// 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.
#ifndef V8_V8_DEBUG_H_
#define V8_V8_DEBUG_H_
#include "v8.h"
/**
* Debugger support for the V8 JavaScript engine.
*/
namespace v8 {
// Debug events which can occur in the V8 JavaScript engine.
enum DebugEvent {
Break = 1,
Exception = 2,
NewFunction = 3,
BeforeCompile = 4,
AfterCompile = 5,
ScriptCollected = 6,
BreakForCommand = 7
};
class V8_EXPORT Debug {
public:
/**
* A client object passed to the v8 debugger whose ownership will be taken by
* it. v8 is always responsible for deleting the object.
*/
class ClientData {
public:
virtual ~ClientData() {}
};
/**
* A message object passed to the debug message handler.
*/
class Message {
public:
/**
* Check type of message.
*/
virtual bool IsEvent() const = 0;
virtual bool IsResponse() const = 0;
virtual DebugEvent GetEvent() const = 0;
/**
* Indicate whether this is a response to a continue command which will
* start the VM running after this is processed.
*/
virtual bool WillStartRunning() const = 0;
/**
* Access to execution state and event data. Don't store these cross
* callbacks as their content becomes invalid. These objects are from the
* debugger event that started the debug message loop.
*/
virtual Handle<Object> GetExecutionState() const = 0;
virtual Handle<Object> GetEventData() const = 0;
/**
* Get the debugger protocol JSON.
*/
virtual Handle<String> GetJSON() const = 0;
/**
* Get the context active when the debug event happened. Note this is not
* the current active context as the JavaScript part of the debugger is
* running in its own context which is entered at this point.
*/
virtual Handle<Context> GetEventContext() const = 0;
/**
* Client data passed with the corresponding request if any. This is the
* client_data data value passed into Debug::SendCommand along with the
* request that led to the message or NULL if the message is an event. The
* debugger takes ownership of the data and will delete it even if there is
* no message handler.
*/
virtual ClientData* GetClientData() const = 0;
virtual Isolate* GetIsolate() const = 0;
virtual ~Message() {}
};
/**
* An event details object passed to the debug event listener.
*/
class EventDetails {
public:
/**
* Event type.
*/
virtual DebugEvent GetEvent() const = 0;
/**
* Access to execution state and event data of the debug event. Don't store
* these cross callbacks as their content becomes invalid.
*/
virtual Handle<Object> GetExecutionState() const = 0;
virtual Handle<Object> GetEventData() const = 0;
/**
* Get the context active when the debug event happened. Note this is not
* the current active context as the JavaScript part of the debugger is
* running in its own context which is entered at this point.
*/
virtual Handle<Context> GetEventContext() const = 0;
/**
* Client data passed with the corresponding callback when it was
* registered.
*/
virtual Handle<Value> GetCallbackData() const = 0;
/**
* Client data passed to DebugBreakForCommand function. The
* debugger takes ownership of the data and will delete it even if
* there is no message handler.
*/
virtual ClientData* GetClientData() const = 0;
virtual ~EventDetails() {}
};
/**
* Debug event callback function.
*
* \param event_details object providing information about the debug event
*
* A EventCallback2 does not take possession of the event data,
* and must not rely on the data persisting after the handler returns.
*/
typedef void (*EventCallback)(const EventDetails& event_details);
/**
* Debug message callback function.
*
* \param message the debug message handler message object
*
* A MessageHandler2 does not take possession of the message data,
* and must not rely on the data persisting after the handler returns.
*/
typedef void (*MessageHandler)(const Message& message);
/**
* Callback function for the host to ensure debug messages are processed.
*/
typedef void (*DebugMessageDispatchHandler)();
static bool SetDebugEventListener(EventCallback that,
Handle<Value> data = Handle<Value>());
// Schedule a debugger break to happen when JavaScript code is run
// in the given isolate.
static void DebugBreak(Isolate* isolate);
// Remove scheduled debugger break in given isolate if it has not
// happened yet.
static void CancelDebugBreak(Isolate* isolate);
// Break execution of JavaScript in the given isolate (this method
// can be invoked from a non-VM thread) for further client command
// execution on a VM thread. Client data is then passed in
// EventDetails to EventCallback2 at the moment when the VM actually
// stops.
static void DebugBreakForCommand(Isolate* isolate, ClientData* data);
// Message based interface. The message protocol is JSON.
static void SetMessageHandler(MessageHandler handler);
static void SendCommand(Isolate* isolate,
const uint16_t* command, int length,
ClientData* client_data = NULL);
/**
* Run a JavaScript function in the debugger.
* \param fun the function to call
* \param data passed as second argument to the function
* With this call the debugger is entered and the function specified is called
* with the execution state as the first argument. This makes it possible to
* get access to information otherwise not available during normal JavaScript
* execution e.g. details on stack frames. Receiver of the function call will
* be the debugger context global object, however this is a subject to change.
* The following example shows a JavaScript function which when passed to
* v8::Debug::Call will return the current line of JavaScript execution.
*
* \code
* function frame_source_line(exec_state) {
* return exec_state.frame(0).sourceLine();
* }
* \endcode
*/
static Local<Value> Call(v8::Handle<v8::Function> fun,
Handle<Value> data = Handle<Value>());
/**
* Returns a mirror object for the given object.
*/
static Local<Value> GetMirror(v8::Handle<v8::Value> obj);
/**
* Makes V8 process all pending debug messages.
*
* From V8 point of view all debug messages come asynchronously (e.g. from
* remote debugger) but they all must be handled synchronously: V8 cannot
* do 2 things at one time so normal script execution must be interrupted
* for a while.
*
* Generally when message arrives V8 may be in one of 3 states:
* 1. V8 is running script; V8 will automatically interrupt and process all
* pending messages;
* 2. V8 is suspended on debug breakpoint; in this state V8 is dedicated
* to reading and processing debug messages;
* 3. V8 is not running at all or has called some long-working C++ function;
* by default it means that processing of all debug messages will be deferred
* until V8 gets control again; however, embedding application may improve
* this by manually calling this method.
*
* Technically this method in many senses is equivalent to executing empty
* script:
* 1. It does nothing except for processing all pending debug messages.
* 2. It should be invoked with the same precautions and from the same context
* as V8 script would be invoked from, because:
* a. with "evaluate" command it can do whatever normal script can do,
* including all native calls;
* b. no other thread should call V8 while this method is running
* (v8::Locker may be used here).
*
* "Evaluate" debug command behavior currently is not specified in scope
* of this method.
*/
static void ProcessDebugMessages();
/**
* Debugger is running in its own context which is entered while debugger
* messages are being dispatched. This is an explicit getter for this
* debugger context. Note that the content of the debugger context is subject
* to change.
*/
static Local<Context> GetDebugContext();
/**
* Enable/disable LiveEdit functionality for the given Isolate
* (default Isolate if not provided). V8 will abort if LiveEdit is
* unexpectedly used. LiveEdit is enabled by default.
*/
static void SetLiveEditEnabled(Isolate* isolate, bool enable);
};
} // namespace v8
#undef EXPORT
#endif // V8_V8_DEBUG_H_