var net = require('net'); var readline = require('readline'); var inherits = require('util').inherits; var spawn = require('child_process').spawn; exports.port = 5858; exports.start = function() { if (process.argv.length < 3) { console.error('Usage: node debug script.js'); process.exit(1); } var interface = new Interface(); process.on('uncaughtException', function(e) { console.error("There was an internal error in Node's debugger. " + 'Please report this bug.'); console.error(e.message); console.error(e.stack); if (interface.child) interface.child.kill(); process.exit(1); }); }; var args = process.argv.slice(2); args.unshift('--debug-brk'); // // Parser/Serializer for V8 debugger protocol // http://code.google.com/p/v8/wiki/DebuggerProtocol // // Usage: // p = new Protocol(); // // p.onResponse = function(res) { // // do stuff with response from V8 // }; // // socket.setEncoding('utf8'); // socket.on('data', function(s) { // // Pass strings into the protocol // p.execute(s); // }); // // function Protocol() { this._newRes(); } exports.Protocol = Protocol; Protocol.prototype._newRes = function(raw) { this.res = { raw: raw || '', headers: {} }; this.state = 'headers'; this.reqSeq = 1; this.execute(''); }; Protocol.prototype.execute = function(d) { var res = this.res; res.raw += d; switch (this.state) { case 'headers': var endHeaderIndex = res.raw.indexOf('\r\n\r\n'); if (endHeaderIndex < 0) break; var lines = res.raw.slice(0, endHeaderIndex).split('\r\n'); for (var i = 0; i < lines.length; i++) { var kv = lines[i].split(/: +/); res.headers[kv[0]] = kv[1]; } this.contentLength = +res.headers['Content-Length']; this.bodyStartIndex = endHeaderIndex + 4; this.state = 'body'; if (res.raw.length - this.bodyStartIndex < this.contentLength) break; // pass thru case 'body': if (res.raw.length - this.bodyStartIndex >= this.contentLength) { res.body = res.raw.slice(this.bodyStartIndex, this.bodyStartIndex + this.contentLength); // JSON parse body? res.body = res.body.length ? JSON.parse(res.body) : {}; // Done! this.onResponse(res); this._newRes(res.raw.slice(this.bodyStartIndex + this.contentLength)); } break; default: throw new Error('Unknown state'); break; } }; Protocol.prototype.serialize = function(req) { req.type = 'request'; req.seq = this.reqSeq++; var json = JSON.stringify(req); return 'Content-Length: ' + json.length + '\r\n\r\n' + json; }; var NO_FRAME = -1; function Client() { net.Stream.call(this); var protocol = this.protocol = new Protocol(this); this._reqCallbacks = []; var socket = this; this.currentFrame = NO_FRAME; this.currentSourceLine = -1; this.currentSource = null; this.handles = {}; this.scripts = {}; // Note that 'Protocol' requires strings instead of Buffers. socket.setEncoding('utf8'); socket.on('data', function(d) { protocol.execute(d); }); protocol.onResponse = this._onResponse.bind(this); } inherits(Client, net.Stream); exports.Client = Client; Client.prototype._addHandle = function(desc) { if (typeof desc != 'object' || typeof desc.handle != 'number') { return; } this.handles[desc.handle] = desc; if (desc.type == 'script') { this._addScript(desc); } }; var natives = process.binding('natives'); Client.prototype._addScript = function(desc) { this.scripts[desc.id] = desc; if (desc.name) { desc.isNative = (desc.name.replace('.js', '') in natives) || desc.name == 'node.js'; } }; Client.prototype._removeScript = function(desc) { this.scripts[desc.id] = undefined; }; Client.prototype._onResponse = function(res) { for (var i = 0; i < this._reqCallbacks.length; i++) { var cb = this._reqCallbacks[i]; if (this._reqCallbacks[i].request_seq == res.body.request_seq) break; } var self = this; var handled = false; if (res.headers.Type == 'connect') { // Request a list of scripts for our own storage. self.reqScripts(); self.emit('ready'); handled = true; } else if (res.body && res.body.event == 'break') { this.emit('break', res.body); handled = true; } else if (res.body && res.body.event == 'afterCompile') { this._addHandle(res.body.body.script); handled = true; } else if (res.body && res.body.event == 'scriptCollected') { // ??? this._removeScript(res.body.body.script); handled = true; } if (cb) { this._reqCallbacks.splice(i, 1); handled = true; cb(res.body); } if (!handled) this.emit('unhandledResponse', res.body); }; Client.prototype.req = function(req, cb) { this.write(this.protocol.serialize(req)); cb.request_seq = req.seq; this._reqCallbacks.push(cb); }; Client.prototype.reqVersion = function(cb) { this.req({ command: 'version' } , function(res) { if (cb) cb(res.body.V8Version, res.running); }); }; Client.prototype.reqLookup = function(refs, cb) { var self = this; // TODO: We have a cache of handle's we've already seen in this.handles // This can be used if we're careful. var req = { command: 'lookup', arguments: { handles: refs } }; this.req(req, function(res) { if (res.success) { for (var ref in res.body) { if (typeof res.body[ref] == 'object') { self._addHandle(res.body[ref]); } } } if (cb) cb(res); }); }; // This is like reqEval, except it will look up the expression in each of the // scopes associated with the current frame. Client.prototype.reqEval = function(expression, cb) { var self = this; if (this.currentFrame == NO_FRAME) { // Only need to eval in global scope. this.reqFrameEval(expression, NO_FRAME, cb); return; } // Otherwise we need to get the current frame to see which scopes it has. this.reqBacktrace(function(bt) { if (!bt.frames) { // ?? cb({}); return; } var frame = bt.frames[self.currentFrame]; var evalFrames = frame.scopes.map(function(s) { return bt.frames[s.index].index; }); self._reqFramesEval(expression, evalFrames, cb); }); }; // Finds the first scope in the array in which the epxression evals. Client.prototype._reqFramesEval = function(expression, evalFrames, cb) { if (evalFrames.length == 0) { // Just eval in global scope. this.reqFrameEval(expression, NO_FRAME, cb); return; } var self = this; var i = evalFrames.shift(); this.reqFrameEval(expression, i, function(res) { if (res.success) { if (cb) cb(res); } else { self._reqFramesEval(expression, evalFrames, cb); } }); }; Client.prototype.reqFrameEval = function(expression, frame, cb) { var self = this; var req = { command: 'evaluate', arguments: { expression: expression } }; if (frame == NO_FRAME) { req.arguments.global = true; } else { req.arguments.frame = frame; } this.req(req, function(res) { if (res.success) { self._addHandle(res.body); } if (cb) cb(res); }); }; // reqBacktrace(cb) // TODO: from, to, bottom Client.prototype.reqBacktrace = function(cb) { this.req({ command: 'backtrace' } , function(res) { if (cb) cb(res.body); }); }; // Returns an array of objects like this: // // { handle: 11, // type: 'script', // name: 'node.js', // id: 14, // lineOffset: 0, // columnOffset: 0, // lineCount: 562, // sourceStart: '(function(process) {\n\n ', // sourceLength: 15939, // scriptType: 2, // compilationType: 0, // context: { ref: 10 }, // text: 'node.js (lines: 562)' } // Client.prototype.reqScripts = function(cb) { var self = this; this.req({ command: 'scripts' } , function(res) { for (var i = 0; i < res.body.length; i++) { self._addHandle(res.body[i]); } if (cb) cb(); }); }; Client.prototype.reqContinue = function(cb) { this.req({ command: 'continue' }, function(res) { if (cb) cb(res); }); }; Client.prototype.listbreakpoints = function(cb) { this.req({ command: 'listbreakpoints' }, function(res) { if (cb) cb(res); }); }; Client.prototype.reqSource = function(from, to, cb) { var req = { command: 'source', fromLine: from, toLine: to }; this.req(req, function(res) { if (cb) cb(res.body); }); }; // client.next(1, cb); Client.prototype.step = function(action, count, cb) { var req = { command: 'continue', arguments: { stepaction: action, stepcount: count } }; this.req(req, function(res) { if (cb) cb(res); }); }; Client.prototype.mirrorObject = function(handle, cb) { var self = this; if (handle.type == 'object') { // The handle looks something like this: // { handle: 8, // type: 'object', // className: 'Object', // constructorFunction: { ref: 9 }, // protoObject: { ref: 4 }, // prototypeObject: { ref: 2 }, // properties: [ { name: 'hello', propertyType: 1, ref: 10 } ], // text: '#' } // For now ignore the className and constructor and prototype. // TJ's method of object inspection would probably be good for this: // https://groups.google.com/forum/?pli=1#!topic/nodejs-dev/4gkWBOimiOg var propertyRefs = handle.properties.map(function(p) { return p.ref; }); this.reqLookup(propertyRefs, function(res) { if (!res.success) { console.error('problem with reqLookup'); if (cb) cb(handle); return; } var mirror; if (handle.className == 'Array') { mirror = []; } else { mirror = {}; } for (var i = 0; i < handle.properties.length; i++) { var value = res.body[handle.properties[i].ref]; var mirrorValue; if (value) { mirrorValue = value.value ? value.value : value.text; } else { mirrorValue = '[?]'; } if (Array.isArray(mirror) && typeof handle.properties[i].name != 'number') { // Skip the 'length' property. continue; } mirror[handle.properties[i].name] = mirrorValue; } if (cb) cb(mirror); }); } else if (handle.value) { process.nextTick(function() { cb(handle.value); }); } else { process.nextTick(function() { cb(handle); }); } }; Client.prototype.fullTrace = function(cb) { var self = this; this.reqBacktrace(function(trace) { var refs = []; for (var i = 0; i < trace.frames.length; i++) { var frame = trace.frames[i]; // looks like this: // { type: 'frame', // index: 0, // receiver: { ref: 1 }, // func: { ref: 0 }, // script: { ref: 7 }, // constructCall: false, // atReturn: false, // debuggerFrame: false, // arguments: [], // locals: [], // position: 160, // line: 7, // column: 2, // sourceLineText: ' debugger;', // scopes: [ { type: 1, index: 0 }, { type: 0, index: 1 } ], // text: '#00 blah() /home/ryan/projects/node/test-debug.js l...' } refs.push(frame.script.ref); refs.push(frame.func.ref); refs.push(frame.receiver.ref); } self.reqLookup(refs, function(res) { for (var i = 0; i < trace.frames.length; i++) { var frame = trace.frames[i]; frame.script = res.body[frame.script.ref]; frame.func = res.body[frame.func.ref]; frame.receiver = res.body[frame.receiver.ref]; } if (cb) cb(trace); }); }); }; var commands = [ 'backtrace', 'continue', 'help', 'info breakpoints', 'kill', 'list', 'next', 'print', 'quit', 'run', 'scripts', 'step', 'version' ]; var helpMessage = 'Commands: ' + commands.join(', '); function SourceUnderline(sourceText, position) { if (!sourceText) return; // Create an underline with a caret pointing to the source position. If the // source contains a tab character the underline will have a tab character in // the same place otherwise the underline will have a space character. var underline = ''; for (var i = 0; i < position; i++) { if (sourceText[i] == '\t') { underline += '\t'; } else { underline += ' '; } } underline += '^'; // Return the source line text with the underline beneath. return sourceText + '\n' + underline; } function SourceInfo(body) { var result = ''; if (body.script) { if (body.script.name) { result += body.script.name; } else { result += '[unnamed]'; } } result += ':'; result += body.sourceLine + 1; return result; } // This class is the readline-enabled debugger interface which is invoked on // "node debug" function Interface() { var self = this; var child; var client; function complete(line) { return self.complete(line); } var term = readline.createInterface(process.stdin, process.stdout, complete); this.term = term; process.on('exit', function() { self.killChild(); }); this.stdin = process.openStdin(); term.setPrompt('debug> '); term.prompt(); this.quitting = false; process.on('SIGINT', function() { self.handleSIGINT(); }); term.on('SIGINT', function() { self.handleSIGINT(); }); term.on('attemptClose', function() { self.tryQuit(); }); term.on('line', function(cmd) { // trim whitespace cmd = cmd.replace(/^\s*/, '').replace(/\s*$/, ''); if (cmd.length) { self._lastCommand = cmd; self.handleCommand(cmd); } else { self.handleCommand(self._lastCommand); } }); } Interface.prototype.complete = function(line) { // Match me with a command. var matches = []; // Remove leading whitespace line = line.replace(/^\s*/, ''); for (var i = 0; i < commands.length; i++) { if (commands[i].indexOf(line) >= 0) { matches.push(commands[i]); } } return [matches, line]; }; Interface.prototype.handleSIGINT = function() { if (this.paused) { this.child.kill('SIGINT'); } else { this.tryQuit(); } }; Interface.prototype.quit = function() { if (this.quitting) return; this.quitting = true; this.killChild(); this.term.close(); process.exit(0); }; Interface.prototype.tryQuit = function() { var self = this; if (self.child) { self.quitQuestion(function(yes) { if (yes) { self.quit(); } else { self.term.prompt(); } }); } else { self.quit(); } }; Interface.prototype.pause = function() { this.paused = true; this.stdin.pause(); this.term.pause(); }; Interface.prototype.resume = function() { if (!this.paused) return false; this.paused = false; this.stdin.resume(); this.term.resume(); this.term.prompt(); return true; }; Interface.prototype.handleBreak = function(r) { var result = ''; if (r.breakpoints) { result += 'breakpoint'; if (r.breakpoints.length > 1) { result += 's'; } result += ' #'; for (var i = 0; i < r.breakpoints.length; i++) { if (i > 0) { result += ', #'; } result += r.breakpoints[i]; } } else { result += 'break'; } result += ' in '; result += r.invocationText; result += ', '; result += SourceInfo(r); result += '\n'; result += SourceUnderline(r.sourceLineText, r.sourceColumn); this.client.currentSourceLine = r.sourceLine; this.client.currentFrame = 0; this.client.currentScript = r.script.name; console.log(result); if (!this.resume()) this.term.prompt(); }; function intChars(n) { // TODO dumb: if (n < 50) { return 2; } else if (n < 950) { return 3; } else if (n < 9950) { return 4; } else { return 5; } } function leftPad(n) { var s = n.toString(); var nchars = intChars(n); var nspaces = nchars - s.length; for (var i = 0; i < nspaces; i++) { s = ' ' + s; } return s; } Interface.prototype.handleCommand = function(cmd) { var self = this; var client = this.client; var term = this.term; if (cmd == 'quit' || cmd == 'q' || cmd == 'exit') { self._lastCommand = null; self.tryQuit(); } else if (/^r(un)?/.test(cmd)) { self._lastCommand = null; if (self.child) { self.restartQuestion(function(yes) { if (!yes) { self._lastCommand = null; term.prompt(); } else { console.log('restarting...'); self.killChild(); // XXX need to wait a little bit for the restart to work? setTimeout(function() { self.trySpawn(); }, 1000); } }); } else { self.trySpawn(); } } else if (/^help/.test(cmd)) { console.log(helpMessage); term.prompt(); } else if ('version' == cmd) { if (!client) { self.printNotConnected(); return; } client.reqVersion(function(v) { console.log(v); term.prompt(); }); } else if (/info +breakpoints/.test(cmd)) { if (!client) { self.printNotConnected(); return; } client.listbreakpoints(function(res) { console.log(res); term.prompt(); }); } else if ('l' == cmd || 'list' == cmd) { if (!client) { self.printNotConnected(); return; } var from = client.currentSourceLine - 5; var to = client.currentSourceLine + 5; client.reqSource(from, to, function(res) { var lines = res.source.split('\n'); for (var i = 0; i < lines.length; i++) { var lineno = res.fromLine + i + 1; if (lineno < from || lineno > to) continue; if (lineno == 1) { // The first line needs to have the module wrapper filtered out of // it. var wrapper = require('module').wrapper[0]; lines[i] = lines[i].slice(wrapper.length); } if (lineno == 1 + client.currentSourceLine) { var nchars = intChars(lineno); var pointer = ''; for (var j = 0; j < nchars - 1; j++) { pointer += '='; } pointer += '>'; console.log(pointer + ' ' + lines[i]); } else { console.log(leftPad(lineno) + ' ' + lines[i]); } } term.prompt(); }); } else if (/^backtrace/.test(cmd) || /^bt/.test(cmd)) { if (!client) { self.printNotConnected(); return; } client.fullTrace(function(bt) { if (bt.totalFrames == 0) { console.log('(empty stack)'); } else { var text = ''; var firstFrameNative = bt.frames[0].script.isNative; for (var i = 0; i < bt.frames.length; i++) { var frame = bt.frames[i]; if (!firstFrameNative && frame.script.isNative) break; text += '#' + i + ' '; if (frame.func.inferredName && frame.func.inferredName.length > 0) { text += frame.func.inferredName + ' '; } text += require('path').basename(frame.script.name) + ':'; text += (frame.line + 1) + ':' + (frame.column + 1); text += '\n'; } console.log(text); } term.prompt(); }); } else if (cmd == 'scripts' || cmd == 'scripts full') { if (!client) { self.printNotConnected(); return; } self.printScripts(cmd.indexOf('full') > 0); term.prompt(); } else if (/^c(ontinue)?/.test(cmd)) { if (!client) { self.printNotConnected(); return; } self.pause(); client.reqContinue(function() { self.resume(); }); } else if (/^k(ill)?/.test(cmd)) { if (!client) { self.printNotConnected(); return; } // kill if (self.child) { self.killQuestion(function(yes) { if (yes) { self.killChild(); } else { self._lastCommand = null; } }); } else { self.term.prompt(); } } else if (/^next/.test(cmd) || /^n/.test(cmd)) { if (!client) { self.printNotConnected(); return; } client.step('next', 1, function(res) { // Wait for break point. (disable raw mode?) }); } else if (/^step/.test(cmd) || /^s/.test(cmd)) { if (!client) { self.printNotConnected(); return; } client.step('in', 1, function(res) { // Wait for break point. (disable raw mode?) }); } else if (/^print/.test(cmd) || /^p/.test(cmd)) { if (!client) { self.printNotConnected(); return; } var i = cmd.indexOf(' '); if (i < 0) { console.log('print [expression]'); term.prompt(); } else { cmd = cmd.slice(i); client.reqEval(cmd, function(res) { if (!res.success) { console.log(res.message); term.prompt(); return; } client.mirrorObject(res.body, function(mirror) { console.log(mirror); term.prompt(); }); }); } } else { if (!/^\s*$/.test(cmd)) { // If it's not all white-space print this error message. console.log('Unknown command "%s". Try "help"', cmd); } term.prompt(); } }; Interface.prototype.yesNoQuestion = function(prompt, cb) { var self = this; self.resume(); this.term.question(prompt, function(answer) { if (/^y(es)?$/i.test(answer)) { cb(true); } else if (/^n(o)?$/i.test(answer)) { cb(false); } else { console.log('Please answer y or n.'); self.restartQuestion(cb); } }); }; Interface.prototype.restartQuestion = function(cb) { this.yesNoQuestion('The program being debugged has been started already.\n' + 'Start it from the beginning? (y or n) ', cb); }; Interface.prototype.killQuestion = function(cb) { this.yesNoQuestion('Kill the program being debugged? (y or n) ', cb); }; Interface.prototype.quitQuestion = function(cb) { this.yesNoQuestion('A debugging session is active. Quit anyway? (y or n) ', cb); }; Interface.prototype.killChild = function() { if (this.child) { this.child.kill(); this.child = null; } if (this.client) { this.client.destroy(); this.client = null; } this.resume(); }; Interface.prototype.trySpawn = function(cb) { var self = this; this.killChild(); this.child = spawn(process.execPath, args, { customFds: [0, 1, 2] }); this.pause(); setTimeout(function() { process.stdout.write('connecting...'); var client = self.client = new Client(); client.connect(exports.port); client.once('ready', function() { process.stdout.write('ok\r\n'); // since we did debug-brk, we're hitting a break point immediately // continue before anything else. client.reqContinue(function() { if (cb) cb(); }); }); client.on('close', function() { console.log('\nprogram terminated'); self.client = null; self.killChild(); if (!self.quitting) self.term.prompt(); }); client.on('unhandledResponse', function(res) { console.log('\r\nunhandled res:'); console.log(res); self.term.prompt(); }); client.on('break', function(res) { self.handleBreak(res.body); }); }, 100); }; Interface.prototype.printNotConnected = function() { console.log("Program not running. Try 'run'."); this.term.prompt(); }; // argument full tells if it should display internal node scripts or not Interface.prototype.printScripts = function(displayNatives) { var client = this.client; var text = ''; for (var id in client.scripts) { var script = client.scripts[id]; if (typeof script == 'object' && script.name) { if (displayNatives || script.name == client.currentScript || !script.isNative) { text += script.name == client.currentScript ? '* ' : ' '; text += require('path').basename(script.name) + '\n'; } } } process.stdout.write(text); };