src,lib: v8-inspector support

This change introduces experimental v8-inspector support. This brings
the DevTools debug protocol allowing Node.js to be debugged with
Chrome DevTools native, or through other debuggers supporting that
protocol.

Partial WebSocket support, to the extent required by DevTools, is
included. This is derived from the implementation in Blink.

v8-inspector support can be disabled by the --without-inspector
configure flag.

PR-URL: #6792
Reviewed-By: jasnell - James M Snell <jasnell@gmail.com>
Reviewed-By: addaleax - Anna Henningsen <anna@addaleax.net>
Reviewed-By: bnoordhuis - Ben Noordhuis <info@bnoordhuis.nl>

configure

@@ -415,6 +415,11 @@ parser.add_option('--no-browser-globals',
     help='do not export browser globals like setTimeout, console, etc. ' +
          '(This mode is not officially supported for regular applications)')
 
+parser.add_option('--without-inspector',
+    action='store_true',
+    dest='without_inspector',
+    help='disable experimental V8 inspector support')
+
 (options, args) = parser.parse_args()
 
 # Expand ~ in the install prefix now, it gets written to multiple files.
@@ -810,6 +815,7 @@ def configure_node(o):
     o['variables']['library_files'] = options.linked_module
 
   o['variables']['asan'] = int(options.enable_asan or 0)
+  o['variables']['v8_inspector'] = b(not options.without_inspector)
 
   if options.use_xcode and options.use_ninja:
     raise Exception('--xcode and --ninja cannot be used together.')

doc/api/debugger.md

@@ -179,4 +179,18 @@ process or via URI reference to the listening debugger:
 * `node debug <URI>` - Connects to the process via the URI such as
 localhost:5858
 
+## V8 Inspector Integration for Node.js
+
+__NOTE: This is an experimental feature.__
+
+V8 Inspector integration allows attaching Chrome DevTools to Node.js
+instances for debugging and profiling.
+
+V8 Inspector can be enabled by passing the `--inspect` flag when starting a
+Node.js application. It is also possible to supply a custom port with that flag,
+e.g. `--inspect=9222` will accept DevTools connections on port 9222.
+
+To break on the first line of the application code, provide the `--debug-brk`
+flag in addition to `--inspect`.
+
 [TCP-based protocol]: https://github.com/v8/v8/wiki/Debugging-Protocol

lib/internal/bootstrap_node.js

@@ -81,6 +81,10 @@
       // Start the debugger agent
       NativeModule.require('_debugger').start();
 
+    } else if (process.argv[1] == '--remote_debugging_server') {
+      // Start the debugging server
+      NativeModule.require('internal/inspector/remote_debugging_server');
+
     } else if (process.argv[1] == '--debug-agent') {
       // Start the debugger agent
       NativeModule.require('_debug_agent').start();

node.gyp

@@ -250,6 +250,28 @@
             'deps/v8/src/third_party/vtune/v8vtune.gyp:v8_vtune'
           ],
         }],
+        [ 'v8_inspector=="true"', {
+          'defines': [
+            'HAVE_INSPECTOR=1',
+            'V8_INSPECTOR_USE_STL=1',
+          ],
+          'sources': [
+            'src/inspector_agent.cc',
+            'src/inspector_socket.cc',
+            'src/inspector_socket.h',
+            'src/inspector-agent.h',
+          ],
+          'dependencies': [
+            'deps/v8_inspector/v8_inspector.gyp:v8_inspector',
+          ],
+          'include_dirs': [
+            'deps/v8_inspector',
+            'deps/v8_inspector/deps/wtf', # temporary
+            '<(SHARED_INTERMEDIATE_DIR)/blink', # for inspector
+          ],
+        }, {
+          'defines': [ 'HAVE_INSPECTOR=0' ]
+        }],
         [ 'node_use_openssl=="true"', {
           'defines': [ 'HAVE_OPENSSL=1' ],
           'sources': [
@@ -690,7 +712,10 @@
       'target_name': 'cctest',
       'type': 'executable',
       'dependencies': [
+        'deps/openssl/openssl.gyp:openssl',
+        'deps/http_parser/http_parser.gyp:http_parser',
         'deps/gtest/gtest.gyp:gtest',
+        'deps/uv/uv.gyp:libuv',
         'deps/v8/tools/gyp/v8.gyp:v8',
         'deps/v8/tools/gyp/v8.gyp:v8_libplatform'
       ],
@@ -711,6 +736,20 @@
       'sources': [
         'test/cctest/util.cc',
       ],
+
+      'conditions': [
+        ['v8_inspector=="true"', {
+          'dependencies': [
+            'deps/openssl/openssl.gyp:openssl',
+            'deps/http_parser/http_parser.gyp:http_parser',
+            'deps/uv/uv.gyp:libuv'
+          ],
+          'sources': [
+            'src/inspector_socket.cc',
+            'test/cctest/test_inspector_socket.cc'
+          ]
+        }]
+      ]
     }
   ], # end targets
 

src/env-inl.h

@@ -225,6 +225,9 @@ inline Environment::Environment(v8::Local<v8::Context> context,
       makecallback_cntr_(0),
       async_wrap_uid_(0),
       debugger_agent_(this),
+#if HAVE_INSPECTOR
+      inspector_agent_(this),
+#endif
       http_parser_buffer_(nullptr),
       context_(context->GetIsolate(), context) {
   // We'll be creating new objects so make sure we've entered the context.

src/env.h

@@ -5,6 +5,9 @@
 
 #include "ares.h"
 #include "debug-agent.h"
+#if HAVE_INSPECTOR
+#include "inspector_agent.h"
+#endif
 #include "handle_wrap.h"
 #include "req-wrap.h"
 #include "tree.h"
@@ -549,6 +552,12 @@ class Environment {
     return &debugger_agent_;
   }
 
+#if HAVE_INSPECTOR
+  inline inspector::Agent* inspector_agent() {
+    return &inspector_agent_;
+  }
+#endif
+
   typedef ListHead<HandleWrap, &HandleWrap::handle_wrap_queue_> HandleWrapQueue;
   typedef ListHead<ReqWrap<uv_req_t>, &ReqWrap<uv_req_t>::req_wrap_queue_>
           ReqWrapQueue;
@@ -586,6 +595,9 @@ class Environment {
   size_t makecallback_cntr_;
   int64_t async_wrap_uid_;
   debugger::Agent debugger_agent_;
+#if HAVE_INSPECTOR
+  inspector::Agent inspector_agent_;
+#endif
 
   HandleWrapQueue handle_wrap_queue_;
   ReqWrapQueue req_wrap_queue_;