Merge DevTools Refactor CL to Blink36

Source/bindings/dart/DartScriptDebugServer.cpp

+/*
+ * Copyright (C) 2014 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "config.h"
+#include "bindings/dart/DartScriptDebugServer.h"
+
+#include "bindings/dart/DartController.h"
+#include "bindings/dart/DartHandleProxy.h"
+#include "bindings/dart/DartUtilities.h"
+#include "bindings/dart/V8Converter.h"
+#include "bindings/v8/PageScriptDebugServer.h"
+#include "bindings/v8/ScriptController.h"
+#include "bindings/v8/ScriptState.h"
+#include "bindings/v8/V8Binding.h"
+#include "bindings/v8/V8WindowShell.h"
+#include "core/dom/Document.h"
+#include "core/frame/DOMWindow.h"
+#include "core/inspector/InspectorController.h"
+#include "core/inspector/InspectorDebuggerAgent.h"
+#include "core/inspector/InspectorInstrumentation.h"
+#include "core/inspector/InstrumentingAgents.h"
+#include "core/inspector/JSONParser.h"
+#include "core/inspector/ScriptDebugListener.h"
+#include "core/page/Page.h"
+#include "platform/JSONValues.h"
+#include "platform/Logging.h"
+#include "wtf/HashMap.h"
+#include "wtf/Vector.h"
+
+namespace WebCore {
+
+static Dart_ExceptionPauseInfo calculatePauseInfo(ScriptDebugServer::PauseOnExceptionsState pauseOnExceptionState)
+{
+    switch (pauseOnExceptionState) {
+    case ScriptDebugServer::DontPauseOnExceptions:
+        return kNoPauseOnExceptions;
+    case ScriptDebugServer::PauseOnAllExceptions:
+        return kPauseOnAllExceptions;
+    case ScriptDebugServer::PauseOnUncaughtExceptions:
+        return kPauseOnUnhandledExceptions;
+    }
+    return kNoPauseOnExceptions;
+}
+
+DartBreakpoint::DartBreakpoint(intptr_t breakpointId, Dart_Isolate isolate)
+    : m_breakpointId(breakpointId)
+    , m_isolate(isolate)
+{
+}
+
+DartBreakpointInfo::DartBreakpointInfo(const String& scriptUrl, const ScriptBreakpoint& scriptBreakpoint)
+    : m_scriptUrl(scriptUrl)
+    , m_scriptBreakpoint(scriptBreakpoint)
+{
+}
+
+DartPageDebug::DartPageDebug(Page* page, size_t pageId)
+    : m_page(page)
+    , m_listener(0)
+    , m_pageId(pageId)
+    , m_nextBreakpointId(1)
+    , m_nextScriptId(1)
+{
+}
+
+DartPageDebug::~DartPageDebug()
+{
+    for (BreakpointMap::iterator it = m_breakpoints.begin(); it != m_breakpoints.end(); ++it)
+        delete it->value;
+}
+
+void DartPageDebug::registerIsolate(Dart_Isolate isolate)
+{
+    m_isolateMap.add(isolate);
+}
+
+intptr_t DartPageDebug::setBreakpointHelper(DartBreakpointInfo* breakpointInfo, const String& breakpointIdString, Dart_Isolate isolate, Dart_Handle& exception)
+{
+    Dart_Handle scriptURL = DartUtilities::convertSourceString(breakpointInfo->m_scriptUrl);
+    // FIXME: use scriptBreakpoint.columnNumber and ScriptBreakpoint.condition as well.
+    Dart_Handle ret = Dart_SetBreakpoint(scriptURL, breakpointInfo->m_scriptBreakpoint.lineNumber + 1);
+    if (Dart_IsError(ret)) {
+        exception = ret;
+        return 0;
+    }
+    ASSERT(Dart_IsInteger(ret));
+    intptr_t breakpointId = DartUtilities::dartToInt(ret, exception);
+    ASSERT(!exception);
+    if (exception) {
+        return 0;
+    }
+    m_breakpointIdMap.set(breakpointId, breakpointIdString);
+    breakpointInfo->m_breakpoints.append(DartBreakpoint(breakpointId, isolate));
+    return breakpointId;
+}
+
+String DartPageDebug::setBreakpoint(const String& sourceID, const ScriptBreakpoint& scriptBreakpoint, int* actualLineNumber, int* actualColumnNumber, bool interstatementLocation)
+{
+    String breakpointIdString = String::format("{\"dartBreakpoint\":%ld,\"page\":%ld}", m_nextBreakpointId, m_pageId);
+
+    m_nextBreakpointId++;
+    if (!m_idToScriptUrlMap.contains(sourceID)) {
+        return "Unable to set breakpoint. Unknown sourceID";
+    }
+    Vector<Dart_Isolate> isolates;
+    m_isolateMap.copyValues(isolates);
+    for (Vector<Dart_Isolate>::iterator it = isolates.begin(); it != isolates.end(); ++it) {
+        Dart_Isolate isolate = *it;
+        DartIsolateScope scope(isolate);
+        DartApiScope apiScope;
+        Dart_Handle exception = 0;
+
+        DartBreakpointInfo* breakpointInfo;
+        BreakpointMap::iterator breakpointIt = m_breakpoints.find(breakpointIdString);
+        if (breakpointIt != m_breakpoints.end()) {
+            breakpointInfo = breakpointIt->value;
+        } else {
+            breakpointInfo = new DartBreakpointInfo(m_idToScriptUrlMap.get(sourceID), scriptBreakpoint);
+            m_breakpoints.set(breakpointIdString, breakpointInfo);
+        }
+
+        intptr_t breakpointId = setBreakpointHelper(breakpointInfo, breakpointIdString, isolate, exception);
+        if (exception) {
+            continue;
+        }
+        Dart_Handle breakpointLine = Dart_GetBreakpointLine(breakpointId);
+        *actualColumnNumber = 0;
+        if (!Dart_IsError(breakpointLine)) {
+            ASSERT(Dart_IsInteger(breakpointLine));
+            *actualLineNumber = DartUtilities::dartToInt(breakpointLine, exception) - 1;
+            ASSERT(!exception);
+        } else {
+            *actualLineNumber = 1;
+        }
+    }
+    return breakpointIdString;
+}
+
+
+void DartPageDebug::removeBreakpointHelper(DartBreakpointInfo* breakpointInfo)
+{
+    Vector<DartBreakpoint>& breakpoints = breakpointInfo->m_breakpoints;
+    for (Vector<DartBreakpoint>::iterator it = breakpoints.begin(); it != breakpoints.end(); ++it) {
+        DartBreakpoint& breakpoint = *it;
+        DartIsolateScope scope(breakpoint.m_isolate);
+        DartApiScope apiScope;
+        // perhaps this isn't needed if the isolate will be removed soon anyway.
+        Dart_RemoveBreakpoint(breakpoint.m_breakpointId);
+    }
+    delete breakpointInfo;
+}
+
+void DartPageDebug::removeBreakpoint(const String& breakpointId)
+{
+    if (m_breakpoints.contains(breakpointId)) {
+        removeBreakpointHelper(m_breakpoints.get(breakpointId));
+        m_breakpoints.remove(breakpointId);
+    }
+}
+
+void DartPageDebug::clearBreakpointsForIsolate(Dart_Isolate isolate)
+{
+    // Warning: this code is O(num_isolates * num_breakpoints)
+    for (BreakpointMap::iterator i = m_breakpoints.begin(); i != m_breakpoints.end(); ++i) {
+        Vector<DartBreakpoint>& breakpoints = i->value->m_breakpoints;
+        for (size_t j = 0; j < breakpoints.size(); j++) {
+            DartBreakpoint& breakpoint = breakpoints[j];
+            if (breakpoint.m_isolate == isolate) {
+                // No need to actually call Dart_RemoveBreakpoint as the
+                // isolate is about to be shut down.
+                breakpoints.remove(j);
+                break;
+            }
+        }
+    }
+}
+
+void DartPageDebug::dispatchDidParseSource(intptr_t libraryId, Dart_Handle scriptURL, Dart_Isolate isolate)
+{
+    ASSERT(Dart_IsString(scriptURL));
+    ScriptDebugListener::Script script;
+    script.url = DartUtilities::toString(scriptURL);
+    String sourceID = getScriptId(script.url);
+    script.source = DartUtilities::toString(Dart_ScriptGetSource(libraryId, scriptURL));
+    // FIXME: track script.sourceMappingURL for dart-dart source map support.
+
+    Dart_Handle info = Dart_ScriptGetTokenInfo(libraryId, scriptURL);
+    ASSERT(Dart_IsList(info));
+    intptr_t infoLength = 0;
+    Dart_Handle ALLOW_UNUSED result = Dart_ListLength(info, &infoLength);
+    ASSERT(!Dart_IsError(result));
+    Dart_Handle elem;
+    int lastLineNumber = 0;
+    int lastColumnNumber = 0;
+    intptr_t lastLineStart = 0;
+    for (intptr_t i = infoLength - 3; i >= 0; i--) {
+        elem = Dart_ListGetAt(info, i);
+        if (Dart_IsNull(elem)) {
+            lastLineStart = i;
+            break;
+        }
+    }
+    Dart_Handle exception = 0;
+    lastLineNumber = DartUtilities::toInteger(Dart_ListGetAt(info, lastLineStart + 1), exception);
+    ASSERT(!exception);
+    lastColumnNumber = DartUtilities::toInteger(Dart_ListGetAt(info, infoLength - 1), exception);
+    ASSERT(!exception);
+
+    script.startLine = 0;
+    script.startColumn = 0;
+    script.endLine = lastLineNumber + 1;
+    script.endColumn = !lastLineNumber ? lastColumnNumber : 0;
+    script.isContentScript = false;
+    script.language = String("dart");
+    script.libraryId = libraryId;
+    m_listener->didParseSource(sourceID, script);
+}
+
+String DartPageDebug::getScriptId(const String& url)
+{
+    HashMap<String, String>::iterator it = m_scriptUrlToIdMap.find(url);
+    if (it == m_scriptUrlToIdMap.end()) {
+        String id = String::format("{\"dartScript\":%ld,\"page\":%ld}", m_nextScriptId, m_pageId);
+        m_nextScriptId++;
+        m_scriptUrlToIdMap.set(url, id);
+        m_idToScriptUrlMap.set(id, url);
+        return id;
+    }
+    return it->value;
+}
+
+void DartPageDebug::clearBreakpoints()
+{
+    for (BreakpointMap::iterator i = m_breakpoints.begin(); i != m_breakpoints.end(); ++i)
+        removeBreakpointHelper(i->value);
+    m_breakpoints.clear();
+    m_breakpointIdMap.clear();
+}
+
+void DartPageDebug::registerIsolateScripts(Dart_Isolate isolate)
+{
+    Dart_Handle libraries = Dart_GetLibraryIds();
+    ASSERT(Dart_IsList(libraries));
+
+    intptr_t librariesLength = 0;
+    Dart_Handle ALLOW_UNUSED result = Dart_ListLength(libraries, &librariesLength);
+    ASSERT(!Dart_IsError(result));
+    for (intptr_t i = 0; i < librariesLength; ++i) {
+        Dart_Handle libraryIdHandle = Dart_ListGetAt(libraries, i);
+        ASSERT(!Dart_IsError(libraryIdHandle));
+        Dart_Handle exception = 0;
+        int64_t int64LibraryId = DartUtilities::toInteger(libraryIdHandle, exception);
+        ASSERT(!exception);
+        intptr_t libraryId = static_cast<intptr_t>(int64LibraryId);
+        ASSERT(libraryId == int64LibraryId);
+
+        Dart_Handle libraryURL = Dart_GetLibraryURL(libraryId);
+        ASSERT(Dart_IsString(libraryURL));
+
+        // FIXMEDART: we may be doing this more than once per library.
+        Dart_SetLibraryDebuggable(libraryId, true);
+
+        Dart_Handle scripts = Dart_GetScriptURLs(libraryURL);
+        ASSERT(Dart_IsList(scripts));
+
+        intptr_t scriptsLength = 0;
+        result = Dart_ListLength(scripts, &scriptsLength);
+        ASSERT(!Dart_IsError(result));
+        for (intptr_t j = 0; j < scriptsLength; ++j) {
+            Dart_Handle scriptURL = Dart_ListGetAt(scripts, j);
+            dispatchDidParseSource(libraryId, scriptURL, isolate);
+        }
+    }
+}
+
+Vector<Dart_Isolate> DartPageDebug::isolates()
+{
+    Vector<Dart_Isolate> result;
+    m_isolateMap.copyValues(result);
+    return result;
+}
+
+void DartPageDebug::addListener(ScriptDebugListener* listener)
+{
+    ASSERT(!m_listener);
+    m_listener = listener;
+
+    Vector<Dart_Isolate> iter = isolates();
+    for (Vector<Dart_Isolate>::iterator i = iter.begin(); i != iter.end(); ++i) {
+        Dart_Isolate isolate = *i;
+        DartIsolateScope scope(isolate);
+        DartApiScope apiScope;
+        isolateLoaded();
+    }
+}
+
+void DartPageDebug::removeListener()
+{
+    m_listener = 0;
+    Vector<Dart_Isolate> iter = isolates();
+    for (Vector<Dart_Isolate>::iterator i = iter.begin(); i != iter.end(); ++i) {
+        Dart_Isolate isolate = *i;
+        DartIsolateScope scope(isolate);
+        DartApiScope apiScope;
+        Dart_SetPausedEventHandler(0);
+        Dart_SetExceptionThrownHandler(0);
+        Dart_SetIsolateEventHandler(0);
+        Dart_SetExceptionPauseInfo(kNoPauseOnExceptions);
+    }
+    // FIXME: Remove all breakpoints set by the agent. JavaScript does not
+    // remove the breakpoints either.
+}
+
+void DartPageDebug::unregisterIsolate(Dart_Isolate isolate)
+{
+    clearBreakpointsForIsolate(isolate);
+    m_isolateMap.removeByValue(isolate);
+}
+
+void DartPageDebug::isolateLoaded()
+{
+    if (!m_listener)
+        return;
+
+    Dart_Isolate isolate = Dart_CurrentIsolate();
+    Dart_SetPausedEventHandler(DartScriptDebugServer::pausedEventHandler);
+    Dart_SetExceptionThrownHandler(DartScriptDebugServer::exceptionHandler);
+    Dart_SetIsolateEventHandler(DartScriptDebugServer::isolateEventHandler);
+
+    Dart_ExceptionPauseInfo pauseInfo = calculatePauseInfo(
+        DartScriptDebugServer::shared().pauseOnExceptionState());
+    Dart_SetExceptionPauseInfo(pauseInfo);
+
+    ASSERT(isolate);
+    // FIXME: we can get rid of the V8Scope once DartScriptState and

[rmacnak, 2014/06/03 17:32:34]

Can we remove this now?

[Jacob, 2014/06/03 20:23:13]

sadly we can't yet. I updated the comment. with some future cleanup we can get
rid of it but the code inside DartController that this calls still has to go
through V8 to get the v8ScriptState. If we clean it up we should be able to
remove this ugly extra V8Scope call but I'd like to do that as a separate CL as
it is not trivial.

+    // ScriptState are refactored.
+    V8Scope v8Scope(DartDOMData::current(), v8::Debug::GetDebugContext());
+
+    LocalFrame* frame = DartUtilities::domWindowForCurrentIsolate()->frame();
+    DartController* controller = DartController::retrieve(frame);
+    Vector<ScriptState*> scriptStates;
+    controller->collectScriptStatesForIsolate(isolate, DartUtilities::currentV8Context(), scriptStates);
+    for (size_t i = 0; i< scriptStates.size(); i++)
+        InspectorInstrumentation::didCreateIsolatedContext(frame, scriptStates[i], 0);
+
+    registerIsolateScripts(isolate);
+
+    for (BreakpointMap::iterator it = m_breakpoints.begin(); it != m_breakpoints.end(); ++it) {
+        Dart_Handle ALLOW_UNUSED exception = 0;
+        setBreakpointHelper(it->value, it->key, isolate, exception);
+    }
+}
+
+String DartPageDebug::lookupBreakpointId(intptr_t dartBreakpointId)
+{
+    if (dartBreakpointId > 0) {
+        BreakpointIdMap::iterator it = m_breakpointIdMap.find(dartBreakpointId);
+        if (it != m_breakpointIdMap.end())
+            return it->value;
+    }
+    return "";
+}
+
+DartScriptDebugServer::DartScriptDebugServer()
+    : m_pauseOnExceptionState(DontPauseOnExceptions)
+    , m_breakpointsActivated(true)
+    , m_runningNestedMessageLoop(false)
+    , m_executionState(0)
+    , m_pausedPage(0)
+    , m_clientMessageLoop(0)
+    , m_nextPageId(1)
+{
+}
+
+DartScriptDebugServer::~DartScriptDebugServer()
+{
+    for (DebugDataMap::iterator it = m_pageIdToDebugDataMap.begin(); it != m_pageIdToDebugDataMap.end(); ++it)
+        delete it->value;
+}
+
+DartPageDebug* DartScriptDebugServer::lookupPageDebugForId(const String& id)
+{
+    RefPtr<JSONValue> json = parseJSON(id);
+    ASSERT(json && json->type() == JSONValue::TypeObject);
+    if (json && json->type() == JSONValue::TypeObject) {
+        size_t pageId;
+        bool success = json->asObject()->getNumber("page", &pageId);
+        ASSERT(success);
+        if (success)
+            return m_pageIdToDebugDataMap.get(pageId);
+    }
+    return 0;
+}
+
+DartPageDebug* DartScriptDebugServer::lookupPageDebug(Page* page)
+{
+    ASSERT(page);
+    PageToIdMap::iterator it = m_pageToIdMap.find(page);
+    if (it != m_pageToIdMap.end())
+        return m_pageIdToDebugDataMap.get(it->value);
+
+    size_t pageId = m_nextPageId++;
+    m_pageToIdMap.set(page, pageId);
+    DartPageDebug* pageDebug = new DartPageDebug(page, pageId);
+    m_pageIdToDebugDataMap.set(pageId, pageDebug);
+    return pageDebug;
+}
+
+String DartScriptDebugServer::getScriptId(const String& url, Dart_Isolate isolate)
+{
+    // FIXME: this is a ugly. It would be better to get the domData for the
+    // specified isolate.
+    ASSERT(isolate == Dart_CurrentIsolate());
+    DartPageDebug* pageDebug = lookupPageDebug(DartUtilities::domWindowForCurrentIsolate()->document()->page());
+    ASSERT(pageDebug);
+    if (!pageDebug)
+        return "";
+    return pageDebug->getScriptId(url);
+}
+
+void DartScriptDebugServer::registerIsolate(Dart_Isolate isolate, Page* page)
+{
+    DartIsolateScope scope(isolate);
+    DartApiScope apiScope;
+
+    DartPageDebug* pageDebug = lookupPageDebug(page);
+    pageDebug->registerIsolate(isolate);
+}
+
+// FIXMEDART: we aren't really handling adding and removing breakpoints
+// as new isolates add/remove themselves.
+String DartScriptDebugServer::setBreakpoint(const String& sourceID, const ScriptBreakpoint& scriptBreakpoint, int* actualLineNumber, int* actualColumnNumber, bool interstatementLocation)
+{
+    DartPageDebug* pageDebug = lookupPageDebugForId(sourceID);
+    ASSERT(pageDebug);
+    if (!pageDebug)
+        return "";
+    return pageDebug->setBreakpoint(sourceID, scriptBreakpoint, actualLineNumber, actualColumnNumber, interstatementLocation);
+}
+
+void DartScriptDebugServer::removeBreakpoint(const String& breakpointId)
+{
+    DartPageDebug* pageDebug = lookupPageDebugForId(breakpointId);
+    if (pageDebug) {
+        pageDebug->removeBreakpoint(breakpointId);
+    }
+}
+
+void DartScriptDebugServer::clearBreakpoints()
+{
+    Vector<DartPageDebug*> list = pages();
+    for (Vector<DartPageDebug*>::iterator it = list.begin(); it != list.end(); ++it)
+        (*it)->clearBreakpoints();
+}
+
+void DartScriptDebugServer::setBreakpointsActivated(bool activated)
+{
+    m_breakpointsActivated = activated;
+}
+
+ScriptDebugServer::PauseOnExceptionsState DartScriptDebugServer::pauseOnExceptionsState()
+{
+    return m_pauseOnExceptionState;
+}
+
+void DartScriptDebugServer::setPauseOnExceptionsState(PauseOnExceptionsState pauseOnExceptionState)
+{
+    if (m_pauseOnExceptionState == pauseOnExceptionState)
+        return;
+    m_pauseOnExceptionState = pauseOnExceptionState;
+
+    Dart_ExceptionPauseInfo pauseInfo = calculatePauseInfo(pauseOnExceptionState);
+
+    Vector<Dart_Isolate> iter = isolates();
+    for (Vector<Dart_Isolate>::iterator it = iter.begin(); it != iter.end(); ++it) {
+        DartIsolateScope scope(*it);
+        DartApiScope apiScope;
+        Dart_SetExceptionPauseInfo(pauseInfo);
+    }
+}
+
+void DartScriptDebugServer::setPauseOnNextStatement(bool pause)
+{
+    if (isPaused())
+        return;
+    if (pause) {
+        debugBreak();
+    } else {
+        cancelDebugBreak();
+    }
+}
+
+bool DartScriptDebugServer::canBreakProgram()
+{
+    if (!m_breakpointsActivated)
+        return false;
+
+    // FIXME: what is the dart equivalent of
+    // v8::HandleScope scope(m_isolate);
+    // return !m_isolate->GetCurrentContext().IsEmpty();
+    // ?
+    return true;
+}
+
+void DartScriptDebugServer::breakProgram()
+{
+    if (!canBreakProgram())
+        return;
+
+    // FIXME: determine if this method needs to be implemented for Dart.
+}
+
+void DartScriptDebugServer::continueProgram()
+{
+    if (isPaused())
+        quitMessageLoopOnPause();
+    m_executionState = 0;
+}
+
+void DartScriptDebugServer::stepIntoStatement()
+{
+    ASSERT(isPaused());
+    Dart_SetStepInto();
+    continueProgram();
+}
+
+void DartScriptDebugServer::stepOverStatement(const ActivationFrame& frame)
+{
+    ASSERT(isPaused());
+    Dart_SetStepOver();
+    continueProgram();
+}
+
+void DartScriptDebugServer::stepOutOfFunction(const ActivationFrame& frame)
+{
+    ASSERT(isPaused());
+    Dart_SetStepOut();
+    continueProgram();
+}
+
+bool DartScriptDebugServer::setScriptSource(const String& sourceID, const String& newContent, bool preview, String* error, RefPtr<TypeBuilder::Debugger::SetScriptSourceError>& errorData, StackTrace* newCallFrames, RefPtr<JSONObject>& result)
+{
+    *error = "Dart does not support live editing source code yet.";
+    return false;
+}
+
+bool DartScriptDebugServer::executeSkipPauseRequest(ScriptDebugListener::SkipPauseRequest request, Dart_StackTrace stackTrace)
+{
+    switch (request) {
+    case ScriptDebugListener::NoSkip:
+        return false;
+    case ScriptDebugListener::Continue:
+        return true;
+    case ScriptDebugListener::StepInto:
+    case ScriptDebugListener::StepOut:
+        break;
+    }
+    ASSERT(0);
+    // FIXMEDART: actually do something jacobr JACOBR
+    return true;
+}
+
+StackTrace DartScriptDebugServer::currentCallFrames()
+{
+    return StackTrace(m_executionState);
+}
+
+StackTrace DartScriptDebugServer::currentCallFramesForAsyncStack()
+{
+    // FIXMEDART: implement propertly. These are the regular not Async call frames.
+    return StackTrace(m_executionState);
+}
+
+bool DartScriptDebugServer::isPaused()
+{
+    return !!m_executionState;
+}
+
+void DartScriptDebugServer::clearCompiledScripts()
+{
+    // FIXMEDART: is this meaningful for Dart?
+    // Currently tracking what scripts have been compiled is handled by a
+    // different class.
+}
+
+void DartScriptDebugServer::setPreprocessorSource(const String& preprocessorSource)
+{
+    // FIXMEDART: support calling a preprocessor on all Dart scripts.
+}
+
+DartScriptDebugServer& DartScriptDebugServer::shared()
+{
+    DEFINE_STATIC_LOCAL(DartScriptDebugServer, server, ());
+    return server;
+}
+
+void DartScriptDebugServer::addListener(ScriptDebugListener* listener, Page* page)
+{
+    ScriptController& scriptController = page->mainFrame()->script();
+    if (!scriptController.canExecuteScripts(NotAboutToExecuteScript))
+        return;
+
+    DartPageDebug* pageDebug = lookupPageDebug(page);
+    pageDebug->addListener(listener);
+}
+
+Vector<DartPageDebug*> DartScriptDebugServer::pages()
+{
+    Vector<DartPageDebug*> result;
+    copyValuesToVector(m_pageIdToDebugDataMap, result);
+    return result;
+}
+
+Vector<Dart_Isolate> DartScriptDebugServer::isolates()
+{
+    Vector<Dart_Isolate> result;
+    Vector<DartPageDebug*> allPages = pages();
+    for (Vector<DartPageDebug*>::iterator it = allPages.begin(); it != allPages.end(); ++it) {
+        Vector<Dart_Isolate> forPage = (*it)->isolates();
+        result.appendRange(forPage.begin(), forPage.end());
+    }
+    return result;
+}
+
+bool DartScriptDebugServer::resolveCodeLocation(const Dart_CodeLocation& location, int* line, int* column)
+{
+    // FIXME: cache the results of calling Dart_ScriptGetTokenInfo to improve
+    // performance.
+    Dart_Handle info = Dart_ScriptGetTokenInfo(location.library_id, location.script_url);
+    ASSERT(Dart_IsList(info));
+    intptr_t infoLength = 0;
+    Dart_Handle ALLOW_UNUSED result = Dart_ListLength(info, &infoLength);
+    ASSERT(!Dart_IsError(result));
+    Dart_Handle elem;
+    bool lineStart = true;
+    int currentLineNumber = 0;
+    for (intptr_t i = 0; i < infoLength; i++) {
+        elem = Dart_ListGetAt(info, i);
+        if (Dart_IsNull(elem)) {
+            lineStart = true;
+        } else {
+            ASSERT(Dart_IsInteger(elem));
+            Dart_Handle exception = 0;
+            int64_t value = DartUtilities::toInteger(elem, exception);
+            ASSERT(!exception);
+            if (lineStart) {
+                // Line number.
+                currentLineNumber = value;
+                lineStart = false;
+            } else {
+                // Token offset.
+                if (value == location.token_pos) {
+                    *line = currentLineNumber;
+                    ASSERT(i + 1 < infoLength);
+                    *column = DartUtilities::toInteger(Dart_ListGetAt(info, i + 1), exception);
+                    ASSERT(!exception);
+                    return true;
+                }
+                i++; // skip columnNumber.
+            }
+        }
+    }
+    return false;
+}
+
+void DartScriptDebugServer::removeListener(ScriptDebugListener* listener, Page* page)
+{
+    if (!m_pageToIdMap.contains(page))
+        return;
+
+    if (m_pausedPage == page)
+        continueProgram();
+
+    DartPageDebug* pageDebug = lookupPageDebug(page);
+    if (pageDebug)
+        pageDebug->removeListener();
+}
+
+void DartScriptDebugServer::setClientMessageLoop(PageScriptDebugServer::ClientMessageLoop* clientMessageLoop)
+{
+    m_clientMessageLoop = clientMessageLoop;
+}
+
+void DartScriptDebugServer::runMessageLoopOnPause(Dart_Isolate isolate)
+{
+    LocalFrame* frame = DartUtilities::domWindowForCurrentIsolate()->frame();
+    m_pausedPage = frame->page();
+
+    // Wait for continue or step command.
+    ASSERT(m_clientMessageLoop);
+    if (m_clientMessageLoop)
+        m_clientMessageLoop->run(m_pausedPage);
+
+    DartPageDebug* pageDebug = lookupPageDebug(m_pausedPage);
+    // The listener may have been removed in the nested loop.
+    if (pageDebug && pageDebug->listener())
+        pageDebug->listener()->didContinue();
+
+    m_pausedPage = 0;
+}
+
+void DartScriptDebugServer::quitMessageLoopOnPause()
+{
+    m_clientMessageLoop->quitNow();
+}
+
+bool DartScriptDebugServer::canPreprocess(LocalFrame* frame)
+{
+    // FIXMEDART: support preprocessing Dart source code.
+    return false;
+}
+
+// Source to Source processing iff debugger enabled and it has loaded a preprocessor.
+PassOwnPtr<ScriptSourceCode> DartScriptDebugServer::preprocess(LocalFrame* frame, const ScriptSourceCode& sourceCode)
+{
+    // FIXMEDART: support preprocessing Dart source code.
+    return PassOwnPtr<ScriptSourceCode>();
+}
+
+String DartScriptDebugServer::preprocessEventListener(LocalFrame* frame, const String& source, const String& url, const String& functionName)
+{
+    // We don't support inline event listeners in Dart so this code should
+    // never be executed.
+    ASSERT_NOT_REACHED();
+    return source;
+}
+
+void DartScriptDebugServer::debugBreak()
+{
+    Vector<Dart_Isolate> iter = isolates();
+    for (Vector<Dart_Isolate>::iterator it = iter.begin(); it != iter.end(); ++it) {
+        Dart_Isolate isolate = *it;
+        if (!m_interruptCalled.contains(isolate)) {
+            m_interruptCalled.add(isolate);
+            Dart_InterruptIsolate(isolate);
+        }
+        m_interruptCancelled.remove(isolate);
+    }
+}
+
+void DartScriptDebugServer::cancelDebugBreak()
+{
+    // FIXME: it would be nice if the DartVM provided an API to directly cancel
+    // a debug break call like V8 does.
+    for (HashSet<Dart_Isolate>::iterator it = m_interruptCalled.begin(); it != m_interruptCalled.end(); ++it) {
+        m_interruptCancelled.add(*it);
+    }
+}
+
+Page* DartScriptDebugServer::inferPage(Dart_Isolate isolate)
+{
+    for (DebugDataMap::iterator it = m_pageIdToDebugDataMap.begin(); it != m_pageIdToDebugDataMap.end(); ++it) {
+        DartPageDebug* pageDebug = it->value;
+        if (pageDebug->containsIsolate(isolate)) {
+            return pageDebug->page();
+        }
+    }
+    return 0;
+}
+
+void DartScriptDebugServer::unregisterIsolate(Dart_Isolate isolate, Page* page)
+{
+    m_interruptCalled.remove(isolate);
+    m_interruptCancelled.remove(isolate);
+    if (!page) {
+        // FIXME: We should instead fix the underlying issue where the
+        // reference to the page is lost before we call unregisterIsolate in
+        // some cases.
+        page = inferPage(isolate);
+        ASSERT(page);
+    }
+    DartPageDebug* pageDebug = lookupPageDebug(page);
+    ASSERT(pageDebug);
+    if (pageDebug)
+        pageDebug->unregisterIsolate(isolate);
+}
+
+void DartScriptDebugServer::isolateLoaded()
+{
+    Page* page = DartUtilities::domWindowForCurrentIsolate()->document()->page();
+    if (!page || !instrumentationForPage(page)->inspectorDebuggerAgent())
+        return;
+
+    DartPageDebug* pageDebug = lookupPageDebug(page);
+    if (!pageDebug)
+        return;
+
+    pageDebug->isolateLoaded();
+}
+
+void DartScriptDebugServer::handleDartDebugEvent(Dart_IsolateId isolateId, intptr_t breakpointId, Dart_Handle exception, const Dart_CodeLocation& location)
+{
+    Dart_Isolate isolate = Dart_GetIsolate(isolateId);
+    ASSERT(isolate);
+    Dart_Handle result = 0;
+    Dart_StackTrace stackTrace = 0;
+    result = Dart_GetStackTrace(&stackTrace);
+    ASSERT(!Dart_IsError(result));
+    result = 0;
+    DartPageDebug* pageDebug = lookupPageDebugForCurrentIsolate();
+    if (!pageDebug)
+        return;
+    ScriptDebugListener* listener = pageDebug->listener();
+    if (listener) {
+        DartIsolateScope scope(isolate);
+        DartApiScope apiScope;
+        ScriptCallFrame topFrame = DartUtilities::getTopFrame(stackTrace, result);
+        if (!result) {
+            if (exception) {
+                if (executeSkipPauseRequest(listener->shouldSkipExceptionPause(topFrame), stackTrace))
+                    return;
+            } else {
+                ScriptDebugListener::SkipPauseRequest skipRequest;
+                if (breakpointId != ILLEGAL_BREAKPOINT_ID)
+                    skipRequest = listener->shouldSkipBreakpointPause(topFrame);
+                else
+                    skipRequest = listener->shouldSkipStepPause(topFrame);
+                if (executeSkipPauseRequest(skipRequest, stackTrace))
+                    return;
+            }
+        }
+        handleProgramBreak(isolate, stackTrace, breakpointId, exception, location);
+    }
+}
+
+DartPageDebug* DartScriptDebugServer::lookupPageDebugForCurrentIsolate()
+{
+    Page* page = DartUtilities::domWindowForCurrentIsolate()->document()->page();
+    return lookupPageDebug(page);
+}
+
+void DartScriptDebugServer::handleProgramBreak(Dart_Isolate isolate, Dart_StackTrace stackTrace, intptr_t dartBreakpointId, Dart_Handle exception, const Dart_CodeLocation& location)
+{
+    ASSERT(isolate == Dart_CurrentIsolate());
+    // Don't allow nested breaks.
+    if (isPaused())
+        return;
+
+    DartPageDebug* pageDebug = lookupPageDebugForCurrentIsolate();
+    if (!pageDebug)
+        return;
+    ScriptDebugListener* listener = pageDebug->listener();
+
+    if (!listener)
+        return;
+
+    Vector<String> breakpointIds;
+    breakpointIds.append(pageDebug->lookupBreakpointId(dartBreakpointId));
+    m_executionState = stackTrace;
+    // FIXME: remove call to DartHandleProxy once ScriptValue is refactored.
+    listener->didPause(DartUtilities::currentScriptState(), currentCallFrames(), exception ? ScriptValue(DartHandleProxy::create(exception), DartUtilities::currentV8Context()->GetIsolate()) : ScriptValue(), breakpointIds);
+
+    m_runningNestedMessageLoop = true;
+    runMessageLoopOnPause(isolate);
+    m_runningNestedMessageLoop = false;
+}
+
+void DartScriptDebugServer::pausedEventHandler(Dart_IsolateId isolateId, intptr_t breakpointId, const Dart_CodeLocation& location)
+{
+    DartScriptDebugServer::shared().handleDartDebugEvent(isolateId, breakpointId, 0, location);
+}
+
+void DartScriptDebugServer::exceptionHandler(Dart_IsolateId isolateId, Dart_Handle exception, Dart_StackTrace trace)
+{
+    DartScriptDebugServer::shared().handleException(isolateId, exception, trace);
+}
+
+void DartScriptDebugServer::isolateEventHandler(Dart_IsolateId isolateId, Dart_IsolateEvent kind)
+{
+    if (kind == kInterrupted) {
+        DartScriptDebugServer::shared().handleInterrupted(isolateId);
+    }
+}
+
+void DartScriptDebugServer::handleInterrupted(Dart_IsolateId isolateId)
+{
+    Dart_Isolate isolate = Dart_GetIsolate(isolateId);
+
+    if (isolate) {
+        ASSERT(isolate == Dart_CurrentIsolate());
+        if (!m_interruptCalled.contains(isolate)) {
+            return;
+        }
+
+        m_interruptCalled.remove(isolate);
+        if (m_interruptCancelled.contains(isolate)) {
+            m_interruptCancelled.remove(isolate);
+            return;
+        }
+
+        // FIXME: this is a bit of a hack. V8 was also set to pause on the next
+        // code execution. If it attempts to pause while in the middle of
+        // internal V8 debugger logic it will crash so before we do anything we
+        // need to cancel the pending pause sent to V8.
+        // Perhaps it would be slightly less hacky to send a message to
+        // ScriptDebugServer instructing it to cancel pausing V8.
+        v8::Debug::CancelDebugBreak(DartUtilities::currentV8Context()->GetIsolate());
+
+        // The user really wants to be paused at the start of the first line of
+        // the Dart method not at the method invocation itself. Otherwise,
+        // stepping to the next call steps out of the executing Dart code
+        // which is not what the user expects.
+        Dart_SetStepInto();
+        continueProgram();
+    }
+}
+
+void DartScriptDebugServer::handleException(Dart_IsolateId isolateId, Dart_Handle exception, Dart_StackTrace trace)
+{
+    Dart_Isolate isolate = Dart_GetIsolate(isolateId);
+    ASSERT(isolate);
+    Dart_CodeLocation location;
+    Dart_Handle ALLOW_UNUSED result;
+    Dart_ActivationFrame frame;
+    result = Dart_GetActivationFrame(trace, 0, &frame);
+    ASSERT(!Dart_IsError(result));
+    result = Dart_ActivationFrameGetLocation(frame, 0, 0, &location);
+    ASSERT(!Dart_IsError(result));
+    handleProgramBreak(isolate, trace, ILLEGAL_BREAKPOINT_ID, exception, location);
+}
+
+void DartScriptDebugServer::runScript(ScriptState* scriptState, const String& scriptId, ScriptValue* result, bool* wasThrown, String* exceptionMessage)
+{
+}
+
+UnifiedScriptDebugServer::UnifiedScriptDebugServer(DartScriptDebugServer* dartScriptDebugServer, PageScriptDebugServer* scriptDebugServer)
+{
+    m_v8 = scriptDebugServer;
+    m_dart = dartScriptDebugServer;
+}
+
+UnifiedScriptDebugServer& UnifiedScriptDebugServer::shared()
+{
+    DEFINE_STATIC_LOCAL(UnifiedScriptDebugServer, server, (&DartScriptDebugServer::shared(), &PageScriptDebugServer::shared()));
+    return server;
+}
+
+String UnifiedScriptDebugServer::setBreakpoint(const String& sourceID, const ScriptBreakpoint& scriptBreakpoint, int* actualLineNumber, int* actualColumnNumber, bool interstatementLocation)
+{
+    if (isDartSourceID(sourceID))
+        return m_dart->setBreakpoint(sourceID, scriptBreakpoint, actualLineNumber, actualColumnNumber, interstatementLocation);
+    return m_v8->setBreakpoint(sourceID, scriptBreakpoint, actualLineNumber, actualColumnNumber, interstatementLocation);
+}
+
+void UnifiedScriptDebugServer::removeBreakpoint(const String& breakpointId)
+{
+    if (isDartBreakpointId(breakpointId))
+        m_dart->removeBreakpoint(breakpointId);
+    else
+        m_v8->removeBreakpoint(breakpointId);
+}
+
+void UnifiedScriptDebugServer::clearBreakpoints()
+{
+    m_v8->clearBreakpoints();
+    m_dart->clearBreakpoints();
+}
+
+void UnifiedScriptDebugServer::setBreakpointsActivated(bool activated)
+{
+    m_v8->setBreakpointsActivated(activated);
+    m_dart->setBreakpointsActivated(activated);
+}
+
+ScriptDebugServer::PauseOnExceptionsState UnifiedScriptDebugServer::pauseOnExceptionsState()
+{
+    // Assume Dart and V8 always have a consistent value for
+    // pauseOnExceptionsState.
+    return m_v8->pauseOnExceptionsState();
+}
+
+void UnifiedScriptDebugServer::setPauseOnExceptionsState(ScriptDebugServer::PauseOnExceptionsState pauseOnExceptionsState)
+{
+    m_dart->setPauseOnExceptionsState(pauseOnExceptionsState);
+    m_v8->setPauseOnExceptionsState(pauseOnExceptionsState);
+}
+
+void UnifiedScriptDebugServer::setPauseOnNextStatement(bool pause)
+{
+    if (isPaused()) {
+        return;
+    }
+    m_v8->setPauseOnNextStatement(pause);
+    m_dart->setPauseOnNextStatement(pause);
+}
+
+bool UnifiedScriptDebugServer::canBreakProgram()
+{
+    return m_v8->canBreakProgram() || m_dart->canBreakProgram();
+}
+
+void UnifiedScriptDebugServer::breakProgram()
+{
+    if (m_v8->canBreakProgram())
+        m_v8->breakProgram();
+    if (m_dart->canBreakProgram())
+        m_dart->breakProgram();
+}
+
+void UnifiedScriptDebugServer::continueProgram()
+{
+    m_v8->continueProgram();
+    m_dart->continueProgram();
+}
+
+void UnifiedScriptDebugServer::stepIntoStatement()
+{
+    if (m_v8->isPaused())
+        m_v8->stepIntoStatement();
+    else
+        m_dart->stepIntoStatement();
+}
+
+void UnifiedScriptDebugServer::stepOverStatement(const ActivationFrame& frame)
+{
+    if (m_v8->isPaused())
+        m_v8->stepOverStatement(frame);
+    else
+        m_dart->stepOverStatement(frame);
+}
+
+void UnifiedScriptDebugServer::stepOutOfFunction(const ActivationFrame& frame)
+{
+    if (m_v8->isPaused())
+        m_v8->stepOutOfFunction(frame);
+    else
+        m_dart->stepOutOfFunction(frame);
+}
+
+bool UnifiedScriptDebugServer::isDartSourceID(const String& sourceID)
+{
+    // FIXMEDART: find a cleaner solution.
+    return sourceID.startsWith(String("{\"dartScript"));
+}
+
+bool UnifiedScriptDebugServer::isDartBreakpointId(const String& breakpointId)
+{
+    // FIXMEDART: find a cleaner solution.
+    return breakpointId.startsWith(String("{\"dartBreakpoint"));
+}
+
+bool UnifiedScriptDebugServer::setScriptSource(const String& sourceID, const String& newContent, bool preview, String* error, RefPtr<TypeBuilder::Debugger::SetScriptSourceError>& errorBuilder, StackTrace* newCallFrames, RefPtr<JSONObject>& result)
+{
+    if (isDartSourceID(sourceID))
+        return m_dart->setScriptSource(sourceID, newContent, preview, error, errorBuilder, newCallFrames, result);
+    return m_v8->setScriptSource(sourceID, newContent, preview, error, errorBuilder, newCallFrames, result);
+}
+
+StackTrace UnifiedScriptDebugServer::currentCallFrames()
+{
+    // FIXMEDART: we need to figure out how to interleave stack traces where possible.
+    StackTrace v8StackTrace = m_v8->currentCallFrames();
+    if (!v8StackTrace.isNull())
+        return v8StackTrace;
+    return m_dart->currentCallFrames();
+}
+
+StackTrace UnifiedScriptDebugServer::currentCallFramesForAsyncStack()
+{
+    // FIXMEDART: we need to figure out how to interleave stack traces where possible.
+    StackTrace v8StackTrace = m_v8->currentCallFramesForAsyncStack();
+    if (!v8StackTrace.isNull())
+        return v8StackTrace;
+    return m_dart->currentCallFramesForAsyncStack();
+}
+
+
+bool UnifiedScriptDebugServer::isPaused()
+{
+    return m_v8->isPaused() || m_dart->isPaused();
+}
+
+bool UnifiedScriptDebugServer::runningNestedMessageLoop()
+{
+    return m_dart->runningNestedMessageLoop() || m_v8->runningNestedMessageLoop();
+}
+
+void UnifiedScriptDebugServer::clearCompiledScripts()
+{
+    m_v8->clearCompiledScripts();
+    m_dart->clearCompiledScripts();
+}
+
+void UnifiedScriptDebugServer::setPreprocessorSource(const String& script)
+{
+    m_v8->setPreprocessorSource(script);
+    m_dart->setPreprocessorSource(script);
+}
+
+void UnifiedScriptDebugServer::preprocessBeforeCompile(const v8::Debug::EventDetails& eventDetails)
+{
+    m_v8->preprocessBeforeCompile(eventDetails);
+    // FIXMEDART: tweak the signature and call for dart.
+}
+
+PassOwnPtr<ScriptSourceCode> UnifiedScriptDebugServer::preprocess(LocalFrame* frame, const ScriptSourceCode& scriptSourceCode)
+{
+    // FIXME: how do we know whether to preprocess with Dart or V8?
+    return m_v8->preprocess(frame, scriptSourceCode);
+}
+
+void UnifiedScriptDebugServer::addListener(ScriptDebugListener* listener, Page* page)
+{
+    m_v8->addListener(listener, page);
+    m_dart->addListener(listener, page);
+}
+
+void UnifiedScriptDebugServer::removeListener(ScriptDebugListener* listener, Page* page)
+{
+    m_v8->removeListener(listener, page);
+    m_dart->removeListener(listener, page);
+}
+
+String UnifiedScriptDebugServer::preprocessEventListener(LocalFrame* frame, const String& source, const String& url, const String& functionName)
+{
+    // FIXME: how do we know whether to preprocess with Dart or V8?
+    return m_v8->preprocessEventListener(frame, source, url, functionName);
+}
+
+void UnifiedScriptDebugServer::runScript(ScriptState* scriptState, const String& scriptId, ScriptValue* result, bool* wasThrown, String* exceptionMessage)
+{
+    // FIXME: support runScript for Dart as well.
+    m_v8->runScript(scriptState, scriptId, result, wasThrown, exceptionMessage);
+}
+
+}