debugger: export `debug_port` to `process`

`process.debug_port` is useful for changing debugger port in runtime,
before starting it (via SIGUSR1).

Using `--port=` argument for debugger repl, tests will run debugger
server on a `common.PORT` (as it usually does for any other servers).

`process._debugEnd()` stops debugger and its server.

* debugger: implemented process._debugEnd(), `node debug --port=5858 app.js`
* test: start debugger repl on common.PORT
* fixes #2613
* fixes #2614

lib/_debugger.js

@@ -1570,11 +1570,12 @@ Interface.prototype.trySpawn = function(cb) {
 
   this.killChild();
 
-  // Connecting to remote debugger
-  // `node debug localhost:5858`
   if (this.args.length === 2) {
     var match = this.args[1].match(/^([^:]+):(\d+)$/);
+
     if (match) {
+      // Connecting to remote debugger
+      // `node debug localhost:5858`
       host = match[1];
       port = parseInt(match[2], 10);
       this.child = {
@@ -1592,6 +1593,14 @@ Interface.prototype.trySpawn = function(cb) {
         }
       };
       process._debugProcess(parseInt(this.args[2], 10));
+    } else {
+      var match = this.args[1].match(/^--port=(\d+)$/);
+      if (match) {
+        // Start debugger on custom port
+        // `node debug --port=5858 app.js`
+        port = parseInt(match[1], 10);
+        this.args.splice(0, 2, '--debug-brk=' + port);
+      }
     }
   }
 

src/node.cc

@@ -1996,8 +1996,24 @@ static Handle<Object> GetFeatures() {
 }
 
 
+static Handle<Value> DebugPortGetter(Local<String> property,
+                                     const AccessorInfo& info) {
+  HandleScope scope;
+  return scope.Close(Integer::NewFromUnsigned(debug_port));
+}
+
+
+static void DebugPortSetter(Local<String> property,
+                            Local<Value> value,
+                            const AccessorInfo& info) {
+  HandleScope scope;
+  debug_port = value->NumberValue();
+}
+
+
 static Handle<Value> DebugProcess(const Arguments& args);
 static Handle<Value> DebugPause(const Arguments& args);
+static Handle<Value> DebugEnd(const Arguments& args);
 
 Handle<Object> SetupProcessObject(int argc, char *argv[]) {
   HandleScope scope;
@@ -2099,6 +2115,10 @@ Handle<Object> SetupProcessObject(int argc, char *argv[]) {
   }
   delete [] execPath;
 
+  process->SetAccessor(String::New("debug_port"),
+                       DebugPortGetter,
+                       DebugPortSetter);
+
 
   // define various internal methods
   NODE_SET_METHOD(process, "_needTickCallback", NeedTickCallback);
@@ -2125,6 +2145,7 @@ Handle<Object> SetupProcessObject(int argc, char *argv[]) {
 
   NODE_SET_METHOD(process, "_debugProcess", DebugProcess);
   NODE_SET_METHOD(process, "_debugPause", DebugPause);
+  NODE_SET_METHOD(process, "_debugEnd", DebugEnd);
 
   NODE_SET_METHOD(process, "dlopen", DLOpen);
 
@@ -2537,6 +2558,16 @@ static Handle<Value> DebugPause(const Arguments& args) {
 }
 
 
+static Handle<Value> DebugEnd(const Arguments& args) {
+  if (debugger_running) {
+    v8::Debug::DisableAgent();
+    debugger_running = false;
+  }
+
+  return Undefined();
+}
+
+
 char** Init(int argc, char *argv[]) {
   // Initialize prog_start_time to get relative uptime.
   uv_uptime(&prog_start_time);

test/simple/test-debugger-repl-utf8.js

@@ -27,7 +27,7 @@ var debug = require('_debugger');
 
 var script = common.fixturesDir + '/breakpoints_utf8.js';
 
-var child = spawn(process.execPath, ['debug', script]);
+var child = spawn(process.execPath, ['debug', '--port=' + common.PORT, script]);
 
 var buffer = '';
 child.stdout.setEncoding('utf-8');
@@ -77,7 +77,7 @@ function addTest(input, output) {
 
 // Initial lines
 addTest(null, [
-  /listening on port 5858/,
+  /listening on port \d+/,
   /connecting... ok/,
   /break in .*:1/,
   /1/, /2/, /3/

test/simple/test-debugger-repl.js

@@ -27,7 +27,7 @@ var debug = require('_debugger');
 
 var script = common.fixturesDir + '/breakpoints.js';
 
-var child = spawn(process.execPath, ['debug', script]);
+var child = spawn(process.execPath, ['debug', '--port=' + common.PORT, script]);
 
 var buffer = '';
 child.stdout.setEncoding('utf-8');
@@ -82,7 +82,7 @@ function addTest(input, output) {
 
 // Initial lines
 addTest(null, [
-  /listening on port 5858/,
+  /listening on port \d+/,
   /connecting... ok/,
   /break in .*:1/,
   /1/, /2/, /3/