v8  4.6.85(node5.12.0)
V8 is Google's open source JavaScript engine
v8-debug.h
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1 // Copyright 2008 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef V8_V8_DEBUG_H_
6 #define V8_V8_DEBUG_H_
7 
8 #include "v8.h"
9 
10 /**
11  * Debugger support for the V8 JavaScript engine.
12  */
13 namespace v8 {
14 
15 // Debug events which can occur in the V8 JavaScript engine.
16 enum DebugEvent {
17  Break = 1,
18  Exception = 2,
25 };
26 
27 
29  public:
30  /**
31  * A client object passed to the v8 debugger whose ownership will be taken by
32  * it. v8 is always responsible for deleting the object.
33  */
34  class ClientData {
35  public:
36  virtual ~ClientData() {}
37  };
38 
39 
40  /**
41  * A message object passed to the debug message handler.
42  */
43  class Message {
44  public:
45  /**
46  * Check type of message.
47  */
48  virtual bool IsEvent() const = 0;
49  virtual bool IsResponse() const = 0;
50  virtual DebugEvent GetEvent() const = 0;
51 
52  /**
53  * Indicate whether this is a response to a continue command which will
54  * start the VM running after this is processed.
55  */
56  virtual bool WillStartRunning() const = 0;
57 
58  /**
59  * Access to execution state and event data. Don't store these cross
60  * callbacks as their content becomes invalid. These objects are from the
61  * debugger event that started the debug message loop.
62  */
63  virtual Local<Object> GetExecutionState() const = 0;
64  virtual Local<Object> GetEventData() const = 0;
65 
66  /**
67  * Get the debugger protocol JSON.
68  */
69  virtual Local<String> GetJSON() const = 0;
70 
71  /**
72  * Get the context active when the debug event happened. Note this is not
73  * the current active context as the JavaScript part of the debugger is
74  * running in its own context which is entered at this point.
75  */
76  virtual Local<Context> GetEventContext() const = 0;
77 
78  /**
79  * Client data passed with the corresponding request if any. This is the
80  * client_data data value passed into Debug::SendCommand along with the
81  * request that led to the message or NULL if the message is an event. The
82  * debugger takes ownership of the data and will delete it even if there is
83  * no message handler.
84  */
85  virtual ClientData* GetClientData() const = 0;
86 
87  virtual Isolate* GetIsolate() const = 0;
88 
89  virtual ~Message() {}
90  };
91 
92 
93  /**
94  * An event details object passed to the debug event listener.
95  */
96  class EventDetails {
97  public:
98  /**
99  * Event type.
100  */
101  virtual DebugEvent GetEvent() const = 0;
102 
103  /**
104  * Access to execution state and event data of the debug event. Don't store
105  * these cross callbacks as their content becomes invalid.
106  */
107  virtual Local<Object> GetExecutionState() const = 0;
108  virtual Local<Object> GetEventData() const = 0;
109 
110  /**
111  * Get the context active when the debug event happened. Note this is not
112  * the current active context as the JavaScript part of the debugger is
113  * running in its own context which is entered at this point.
114  */
115  virtual Local<Context> GetEventContext() const = 0;
116 
117  /**
118  * Client data passed with the corresponding callback when it was
119  * registered.
120  */
121  virtual Local<Value> GetCallbackData() const = 0;
122 
123  /**
124  * Client data passed to DebugBreakForCommand function. The
125  * debugger takes ownership of the data and will delete it even if
126  * there is no message handler.
127  */
128  virtual ClientData* GetClientData() const = 0;
129 
130  virtual ~EventDetails() {}
131  };
132 
133  /**
134  * Debug event callback function.
135  *
136  * \param event_details object providing information about the debug event
137  *
138  * A EventCallback2 does not take possession of the event data,
139  * and must not rely on the data persisting after the handler returns.
140  */
141  typedef void (*EventCallback)(const EventDetails& event_details);
142 
143  /**
144  * Debug message callback function.
145  *
146  * \param message the debug message handler message object
147  *
148  * A MessageHandler2 does not take possession of the message data,
149  * and must not rely on the data persisting after the handler returns.
150  */
151  typedef void (*MessageHandler)(const Message& message);
152 
153  /**
154  * Callback function for the host to ensure debug messages are processed.
155  */
156  typedef void (*DebugMessageDispatchHandler)();
157 
158  static bool SetDebugEventListener(EventCallback that,
159  Local<Value> data = Local<Value>());
160 
161  // Schedule a debugger break to happen when JavaScript code is run
162  // in the given isolate.
163  static void DebugBreak(Isolate* isolate);
164 
165  // Remove scheduled debugger break in given isolate if it has not
166  // happened yet.
167  static void CancelDebugBreak(Isolate* isolate);
168 
169  // Check if a debugger break is scheduled in the given isolate.
170  static bool CheckDebugBreak(Isolate* isolate);
171 
172  // Message based interface. The message protocol is JSON.
173  static void SetMessageHandler(MessageHandler handler);
174 
175  static void SendCommand(Isolate* isolate,
176  const uint16_t* command, int length,
177  ClientData* client_data = NULL);
178 
179  /**
180  * Run a JavaScript function in the debugger.
181  * \param fun the function to call
182  * \param data passed as second argument to the function
183  * With this call the debugger is entered and the function specified is called
184  * with the execution state as the first argument. This makes it possible to
185  * get access to information otherwise not available during normal JavaScript
186  * execution e.g. details on stack frames. Receiver of the function call will
187  * be the debugger context global object, however this is a subject to change.
188  * The following example shows a JavaScript function which when passed to
189  * v8::Debug::Call will return the current line of JavaScript execution.
190  *
191  * \code
192  * function frame_source_line(exec_state) {
193  * return exec_state.frame(0).sourceLine();
194  * }
195  * \endcode
196  */
197  static V8_DEPRECATE_SOON(
198  "Use maybe version",
199  Local<Value> Call(v8::Local<v8::Function> fun,
200  Local<Value> data = Local<Value>()));
201  // TODO(dcarney): data arg should be a MaybeLocal
202  static MaybeLocal<Value> Call(Local<Context> context,
203  v8::Local<v8::Function> fun,
204  Local<Value> data = Local<Value>());
205 
206  /**
207  * Returns a mirror object for the given object.
208  */
209  static V8_DEPRECATE_SOON("Use maybe version",
210  Local<Value> GetMirror(v8::Local<v8::Value> obj));
211  static MaybeLocal<Value> GetMirror(Local<Context> context,
212  v8::Local<v8::Value> obj);
213 
214  /**
215  * Makes V8 process all pending debug messages.
216  *
217  * From V8 point of view all debug messages come asynchronously (e.g. from
218  * remote debugger) but they all must be handled synchronously: V8 cannot
219  * do 2 things at one time so normal script execution must be interrupted
220  * for a while.
221  *
222  * Generally when message arrives V8 may be in one of 3 states:
223  * 1. V8 is running script; V8 will automatically interrupt and process all
224  * pending messages;
225  * 2. V8 is suspended on debug breakpoint; in this state V8 is dedicated
226  * to reading and processing debug messages;
227  * 3. V8 is not running at all or has called some long-working C++ function;
228  * by default it means that processing of all debug messages will be deferred
229  * until V8 gets control again; however, embedding application may improve
230  * this by manually calling this method.
231  *
232  * Technically this method in many senses is equivalent to executing empty
233  * script:
234  * 1. It does nothing except for processing all pending debug messages.
235  * 2. It should be invoked with the same precautions and from the same context
236  * as V8 script would be invoked from, because:
237  * a. with "evaluate" command it can do whatever normal script can do,
238  * including all native calls;
239  * b. no other thread should call V8 while this method is running
240  * (v8::Locker may be used here).
241  *
242  * "Evaluate" debug command behavior currently is not specified in scope
243  * of this method.
244  */
245  static void ProcessDebugMessages();
246 
247  /**
248  * Debugger is running in its own context which is entered while debugger
249  * messages are being dispatched. This is an explicit getter for this
250  * debugger context. Note that the content of the debugger context is subject
251  * to change. The Context exists only when the debugger is active, i.e. at
252  * least one DebugEventListener or MessageHandler is set.
253  */
254  static Local<Context> GetDebugContext();
255 
256 
257  /**
258  * Enable/disable LiveEdit functionality for the given Isolate
259  * (default Isolate if not provided). V8 will abort if LiveEdit is
260  * unexpectedly used. LiveEdit is enabled by default.
261  */
262  static void SetLiveEditEnabled(Isolate* isolate, bool enable);
263 
264  /**
265  * Returns array of internal properties specific to the value type. Result has
266  * the following format: [<name>, <value>,...,<name>, <value>]. Result array
267  * will be allocated in the current context.
268  */
269  static MaybeLocal<Array> GetInternalProperties(Isolate* isolate,
270  Local<Value> value);
271 };
272 
273 
274 } // namespace v8
275 
276 
277 #undef EXPORT
278 
279 
280 #endif // V8_V8_DEBUG_H_
virtual Local< Value > GetCallbackData() const =0
virtual DebugEvent GetEvent() const =0
virtual Local< Context > GetEventContext() const =0
virtual bool WillStartRunning() const =0
virtual Local< Object > GetEventData() const =0
virtual ~Message()
Definition: v8-debug.h:89
static MaybeLocal< Value > Call(Local< Context > context, v8::Local< v8::Function > fun, Local< Value > data=Local< Value >())
Definition: v8.h:1683
virtual Local< Object > GetExecutionState() const =0
DebugEvent
Definition: v8-debug.h:16
static Local< Context > GetDebugContext()
virtual DebugEvent GetEvent() const =0
virtual bool IsEvent() const =0
static bool SetDebugEventListener(EventCallback that, Local< Value > data=Local< Value >())
virtual ClientData * GetClientData() const =0
static MaybeLocal< Value > GetMirror(Local< Context > context, v8::Local< v8::Value > obj)
virtual bool IsResponse() const =0
virtual Local< Context > GetEventContext() const =0
virtual ~EventDetails()
Definition: v8-debug.h:130
#define V8_DEPRECATE_SOON(message, declarator)
Definition: v8config.h:347
virtual Isolate * GetIsolate() const =0
virtual Local< String > GetJSON() const =0
void(* MessageHandler)(const Message &message)
Definition: v8-debug.h:151
Definition: libplatform.h:10
V8_INLINE Local()
Definition: v8.h:212
static void DebugBreak(Isolate *isolate)
static bool CheckDebugBreak(Isolate *isolate)
Definition: v8.h:2945
static MaybeLocal< Array > GetInternalProperties(Isolate *isolate, Local< Value > value)
static void CancelDebugBreak(Isolate *isolate)
virtual ClientData * GetClientData() const =0
virtual Local< Object > GetEventData() const =0
static void SendCommand(Isolate *isolate, const uint16_t *command, int length, ClientData *client_data=NULL)
virtual ~ClientData()
Definition: v8-debug.h:36
static void SetMessageHandler(MessageHandler handler)
void(* EventCallback)(const EventDetails &event_details)
Definition: v8-debug.h:141
static void SetLiveEditEnabled(Isolate *isolate, bool enable)
#define V8_EXPORT
Definition: v8.h:58
virtual Local< Object > GetExecutionState() const =0
static void ProcessDebugMessages()
void(* DebugMessageDispatchHandler)()
Definition: v8-debug.h:156