debug.cc.svn-base

Google浏览器V8内核代码

        prev->set_next(current->next());
      }
      current->debug_info()->shared()->set_debug_info(Heap::undefined_value());
      delete current;

      // If there are no more debug info objects there are not more break
      // points.
      has_break_points_ = debug_info_list_ != NULL;

      return;
    }
    // Move to next in list.
    prev = current;
    current = current->next();
  }
  UNREACHABLE();
}


void Debug::SetAfterBreakTarget(JavaScriptFrame* frame) {
  // Get the executing function in which the debug break occurred.
  Handle<SharedFunctionInfo> shared =
      Handle<SharedFunctionInfo>(JSFunction::cast(frame->function())->shared());
  if (!EnsureDebugInfo(shared)) {
    // Return if we failed to retrieve the debug info.
    return;
  }
  Handle<DebugInfo> debug_info = GetDebugInfo(shared);
  Handle<Code> code(debug_info->code());
  Handle<Code> original_code(debug_info->original_code());
#ifdef DEBUG
  // Get the code which is actually executing.
  Handle<Code> frame_code(frame->FindCode());
  ASSERT(frame_code.is_identical_to(code));
#endif

  // Find the call address in the running code. This address holds the call to
  // either a DebugBreakXXX or to the debug break return entry code if the
  // break point is still active after processing the break point.
  Address addr = frame->pc() - Assembler::kTargetAddrToReturnAddrDist;

  // Check if the location is at JS exit.
  bool at_js_exit = false;
  RelocIterator it(debug_info->code());
  while (!it.done()) {
    if (RelocInfo::IsJSReturn(it.rinfo()->rmode())) {
      at_js_exit = it.rinfo()->pc() == addr - 1;
    }
    it.next();
  }

  // Handle the jump to continue execution after break point depending on the
  // break location.
  if (at_js_exit) {
    // First check if the call in the code is still the debug break return
    // entry code. If it is the break point is still active. If not the break
    // point was removed during break point processing.
    if (Assembler::target_address_at(addr) ==
        debug_break_return_entry()->entry()) {
      // Break point still active. Jump to the corresponding place in the
      // original code.
      addr +=  original_code->instruction_start() - code->instruction_start();
    }

    // Move one byte back to where the call instruction was placed.
    thread_local_.after_break_target_ = addr - 1;
  } else {
    // Check if there still is a debug break call at the target address. If the
    // break point has been removed it will have disappeared. If it have
    // disappeared don't try to look in the original code as the running code
    // will have the right address. This takes care of the case where the last
    // break point is removed from the function and therefore no "original code"
    // is available. If the debug break call is still there find the address in
    // the original code.
    if (IsDebugBreak(Assembler::target_address_at(addr))) {
      // If the break point is still there find the call address which was
      // overwritten in the original code by the call to DebugBreakXXX.

      // Find the corresponding address in the original code.
      addr += original_code->instruction_start() - code->instruction_start();
    }

    // Install jump to the call address in the original code. This will be the
    // call which was overwritten by the call to DebugBreakXXX.
    thread_local_.after_break_target_ = Assembler::target_address_at(addr);
  }
}


Code* Debug::GetCodeTarget(Address target) {
  // Maybe this can be refactored with the stuff in ic-inl.h?
  Code* result =
      Code::cast(HeapObject::FromAddress(target - Code::kHeaderSize));
  return result;
}


bool Debug::IsDebugGlobal(GlobalObject* global) {
  return IsLoaded() && global == Debug::debug_context()->global();
}


bool Debugger::debugger_active_ = false;
bool Debugger::compiling_natives_ = false;
bool Debugger::is_loading_debugger_ = false;
DebugMessageThread* Debugger::message_thread_ = NULL;
v8::DebugMessageHandler Debugger::debug_message_handler_ = NULL;
void* Debugger::debug_message_handler_data_ = NULL;


Handle<Object> Debugger::MakeJSObject(Vector<const char> constructor_name,
                                      int argc, Object*** argv,
                                      bool* caught_exception) {
  ASSERT(Top::context() == *Debug::debug_context());

  // Create the execution state object.
  Handle<String> constructor_str = Factory::LookupSymbol(constructor_name);
  Handle<Object> constructor(Top::global()->GetProperty(*constructor_str));
  ASSERT(constructor->IsJSFunction());
  if (!constructor->IsJSFunction()) {
    *caught_exception = true;
    return Factory::undefined_value();
  }
  Handle<Object> js_object = Execution::TryCall(
      Handle<JSFunction>::cast(constructor),
      Handle<JSObject>(Debug::debug_context()->global()), argc, argv,
      caught_exception);
  return js_object;
}


Handle<Object> Debugger::MakeExecutionState(bool* caught_exception) {
  // Create the execution state object.
  Handle<Object> break_id = Factory::NewNumberFromInt(Top::break_id());
  const int argc = 1;
  Object** argv[argc] = { break_id.location() };
  return MakeJSObject(CStrVector("MakeExecutionState"),
                      argc, argv, caught_exception);
}


Handle<Object> Debugger::MakeBreakEvent(Handle<Object> exec_state,
                                        Handle<Object> break_points_hit,
                                        bool* caught_exception) {
  // Create the new break event object.
  const int argc = 2;
  Object** argv[argc] = { exec_state.location(),
                          break_points_hit.location() };
  return MakeJSObject(CStrVector("MakeBreakEvent"),
                      argc,
                      argv,
                      caught_exception);
}


Handle<Object> Debugger::MakeExceptionEvent(Handle<Object> exec_state,
                                            Handle<Object> exception,
                                            bool uncaught,
                                            bool* caught_exception) {
  // Create the new exception event object.
  const int argc = 3;
  Object** argv[argc] = { exec_state.location(),
                          exception.location(),
                          uncaught ? Factory::true_value().location() :
                                     Factory::false_value().location()};
  return MakeJSObject(CStrVector("MakeExceptionEvent"),
                      argc, argv, caught_exception);
}


Handle<Object> Debugger::MakeNewFunctionEvent(Handle<Object> function,
                                              bool* caught_exception) {
  // Create the new function event object.
  const int argc = 1;
  Object** argv[argc] = { function.location() };
  return MakeJSObject(CStrVector("MakeNewFunctionEvent"),
                      argc, argv, caught_exception);
}


Handle<Object> Debugger::MakeCompileEvent(Handle<Script> script,
                                          Handle<Object> script_function,
                                          bool* caught_exception) {
  // Create the compile event object.
  Handle<Object> exec_state = MakeExecutionState(caught_exception);
  Handle<Object> script_source(script->source());
  Handle<Object> script_name(script->name());
  const int argc = 3;
  Object** argv[argc] = { script_source.location(),
                          script_name.location(),
                          script_function.location() };
  return MakeJSObject(CStrVector("MakeCompileEvent"),
                      argc,
                      argv,
                      caught_exception);
}


Handle<String> Debugger::ProcessRequest(Handle<Object> exec_state,
                                        Handle<Object> request,
                                        bool stopped) {
  // Get the function ProcessDebugRequest (declared in debug.js).
  Handle<JSFunction> process_denbug_request =
    Handle<JSFunction>(JSFunction::cast(
    Debug::debug_context()->global()->GetProperty(
        *Factory::LookupAsciiSymbol("ProcessDebugRequest"))));

  // Call ProcessDebugRequest expect String result. The ProcessDebugRequest
  // will never throw an exception (see debug.js).
  bool caught_exception;
  const int argc = 3;
  Object** argv[argc] = { exec_state.location(),
                          request.location(),
                          stopped ? Factory::true_value().location() :
                                    Factory::false_value().location()};
  Handle<Object> result = Execution::TryCall(process_denbug_request,
                                             Factory::undefined_value(),
                                             argc, argv,
                                             &caught_exception);
  if (caught_exception) {
    return Factory::empty_symbol();
  }

  return Handle<String>::cast(result);
}


void Debugger::OnException(Handle<Object> exception, bool uncaught) {
  HandleScope scope;

  // Bail out based on state or if there is no listener for this event
  if (Debug::InDebugger()) return;
  if (!Debugger::EventActive(v8::Exception)) return;

  // Bail out if exception breaks are not active
  if (uncaught) {
    // Uncaught exceptions are reported by either flags.
    if (!(Debug::break_on_uncaught_exception() ||
          Debug::break_on_exception())) return;
  } else {
    // Caught exceptions are reported is activated.
    if (!Debug::break_on_exception()) return;
  }

  // Enter the debugger.  Bail out if the debugger cannot be loaded.
  if (!Debug::Load()) return;
  SaveBreakFrame save;
  EnterDebuggerContext enter;

  // Clear all current stepping setup.
  Debug::ClearStepping();
  // Create the event data object.
  bool caught_exception = false;
  Handle<Object> exec_state = MakeExecutionState(&caught_exception);
  Handle<Object> event_data;
  if (!caught_exception) {
    event_data = MakeExceptionEvent(exec_state, exception, uncaught,
                                    &caught_exception);
  }
  // Bail out and don't call debugger if exception.
  if (caught_exception) {
    return;
  }

  // Process debug event
  ProcessDebugEvent(v8::Exception, event_data);
  // Return to continue execution from where the exception was thrown.
}


void Debugger::OnDebugBreak(Handle<Object> break_points_hit) {
  HandleScope scope;

  // Debugger has already been entered by caller.
  ASSERT(Top::context() == *Debug::debug_context());

  // Bail out if there is no listener for this event
  if (!Debugger::EventActive(v8::Break)) return;

  // Debugger must be entered in advance.
  ASSERT(Top::context() == *Debug::debug_context());

  // Create the event data object.
  bool caught_exception = false;
  Handle<Object> exec_state = MakeExecutionState(&caught_exception);
  Handle<Object> event_data;
  if (!caught_exception) {
    event_data = MakeBreakEvent(exec_state, break_points_hit,
                                &caught_exception);
  }
  // Bail out and don't call debugger if exception.
  if (caught_exception) {
    return;
  }

  // Process debug event
  ProcessDebugEvent(v8::Break, event_data);
}


void Debugger::OnBeforeCompile(Handle<Script> script) {
  HandleScope scope;

  // Bail out based on state or if there is no listener for this event
  if (Debug::InDebugger()) return;
  if (compiling_natives()) return;
  if (!EventActive(v8::BeforeCompile)) return;

  // Enter the debugger.  Bail out if the debugger cannot be loaded.
  if (!Debug::Load()) return;
  SaveBreakFrame save;
  EnterDebuggerContext enter;

  // Create the event data object.
  bool caught_exception = false;
  Handle<Object> event_data = MakeCompileEvent(script,
                                               Factory::undefined_value(),
                                               &caught_exception);
  // Bail out and don't call debugger if exception.
  if (caught_exception) {
    return;
  }

  // Process debug event
  ProcessDebugEvent(v8::BeforeCompile, event_data);
}


// Handle debugger actions when a new script is compiled.
void Debugger::OnAfterCompile(Handle<Script> script, Handle<JSFunction> fun) {
  HandleScope scope;

  // No compile events while compiling natives.
  if (compiling_natives()) return;

  // No more to do if not debugging.
  if (!debugger_active()) return;

  // Enter the debugger.  Bail out if the debugger cannot be loaded.
  if (!Debug::Load()) return;
  SaveBreakFrame save;
  EnterDebuggerContext enter;

  // If debugging there might be script break points registered for this
  // script. Make sure that these break points are set.

  // Get the function UpdateScriptBreakPoints (defined in debug-delay.js).
  Handle<Object> update_script_break_points =
      Handle<Object>(Debug::debug_context()->global()->GetProperty(
          *Factory::LookupAsciiSymbol("UpdateScriptBreakPoints")));
  if (!update_script_break_points->IsJSFunction()) {
    return;
  }
  ASSERT(update_script_break_points->IsJSFunction());

  // Wrap the script object in a proper JS object before passing it
  // to JavaScript.
  Handle<JSValue> wrapper = GetScriptWrapper(script);

  // Call UpdateScriptBreakPoints expect no exceptions.
  bool caught_exception = false;
  const int argc = 1;
  Object** argv[argc] = { reinterpret_cast<Object**>(wrapper.location()) };
  Handle<Object> result = Execution::TryCall(
      Handle<JSFunction>::cast(update_script_break_points),
      Top::builtins(), argc, argv,
      &caught_exception);
  if (caught_exception) {
    return;
  }
  // Bail out based on state or if there is no listener for this event
  if (Debug::InDebugger()) return;
  if (!Debugger::EventActive(v8::AfterCompile)) return;

  // Create the compile state object.
  Handle<Object> event_data = MakeCompileEvent(script,
                                               Factory::undefined_value(),
                                               &caught_exception);
  // Bail out and don't call debugger if exception.
  if (caught_exception) {
    return;
  }
  // Process debug event
  ProcessDebugEvent(v8::AfterCompile, event_data);
}


void Debugger::OnNewFunction(Handle<JSFunction> function) {
  return;
  HandleScope scope;