Debugger: Fix QML extra stack loading for GDB

Change-Id: I702bb8f183e93fe25857115225fa55607ffb1674
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

share/qtcreator/debugger/gdbbridge.py

@@ -998,9 +998,10 @@ class Dumper(DumperBase):
         gdb.execute('continue')
 
     def fetchStack(self, args):
-        def fromNativePath(str):
-            return str.replace('\\', '/')
+        def fromNativePath(string):
+            return string.replace('\\', '/')
 
+        extraQml = int(args.get('extraqml', '0'))
         limit = int(args['limit'])
         if limit <= 0:
            limit = 10000
@@ -1008,8 +1009,42 @@ class Dumper(DumperBase):
         self.prepare(args)
         self.output = []
 
-        frame = gdb.newest_frame()
         i = 0
+        if extraQml:
+            frame = gdb.newest_frame()
+            ns = self.qtNamespace()
+            needle = self.qtNamespace() + 'QV4::ExecutionEngine'
+            pat = "%sqt_v4StackTrace(((%sQV4::ExecutionEngine *)0x%x)->currentContext)"
+            done = False
+            while i < limit and frame and not done:
+                block = None
+                try:
+                    block = frame.block()
+                except:
+                    pass
+                if block is not None:
+                    for symbol in block:
+                        if symbol.is_variable or symbol.is_argument:
+                            value = symbol.value(frame)
+                            typeobj = value.type
+                            if typeobj.code == gdb.TYPE_CODE_PTR:
+                               dereftype = typeobj.target().unqualified()
+                               if dereftype.name == needle:
+                                    addr = toInteger(value)
+                                    expr = pat % (ns, ns, addr)
+                                    res = str(gdb.parse_and_eval(expr))
+                                    pos = res.find('"stack=[')
+                                    if pos != -1:
+                                        res = res[pos + 8:-2]
+                                        res = res.replace('\\\"', '\"')
+                                        res = res.replace('func=', 'function=')
+                                        self.put(res)
+                                        done = True
+                                        break
+                frame = frame.older()
+                i += 1
+
+        frame = gdb.newest_frame()
         self.currentCallContext = None
         while i < limit and frame:
             with OutputSafer(self):

src/plugins/debugger/debuggerprotocol.cpp

@@ -249,9 +249,12 @@ void GdbMi::parseList(const QChar *&from, const QChar *to)
         }
         GdbMi child;
         child.parseResultOrValue(from, to);
-        if (child.isValid())
+        if (child.isValid()) {
             m_children.push_back(child);
-        skipCommas(from, to);
+            skipCommas(from, to);
+        } else {
+            ++from;
+        }
     }
 }
 

src/plugins/debugger/gdb/gdbengine.cpp

@@ -3232,58 +3232,13 @@ static quint64 findJsExecutionContextAddress(const GdbMi &stackArgsResponse, con
 
 void GdbEngine::loadAdditionalQmlStack()
 {
-    // Scan for QV4::ExecutionContext parameter in the parameter list of a V4 call.
-    DebuggerCommand cmd("-stack-list-arguments --simple-values", NeedsStop);
-    cmd.callback = [this](const DebuggerResponse &response) {
-        if (!response.data.isValid()) {
-            showMessage(msgCannotLoadQmlStack("No stack obtained."), LogError);
-            return;
-        }
-        const quint64 contextAddress = findJsExecutionContextAddress(response.data, qtNamespace());
-        if (!contextAddress) {
-            showMessage(msgCannotLoadQmlStack("The address of the JS execution context could not be found."), LogError);
-            return;
-        }
-        // Call the debug function of QML with the context address to obtain the QML stack trace.
-        DebuggerCommand cmd;
-        cmd.function = "-data-evaluate-expression \"qt_v4StackTrace((QV4::ExecutionContext *)0x"
-                            + QString::number(contextAddress, 16) + ")\"";
-        cmd.callback = CB(handleQmlStackTrace);
-        runCommand(cmd);
-    };
+    DebuggerCommand cmd = stackCommand(-1);
+    cmd.arg("extraqml", "1");
+    cmd.callback = [this](const DebuggerResponse &r) { handleStackListFrames(r, true); };
+    cmd.flags = Discardable | PythonCommand;
     runCommand(cmd);
 }
 
-// Scan the arguments of a stack list for the address of a QV4::ExecutionContext.
-void GdbEngine::handleQmlStackTrace(const DebuggerResponse &response)
-{
-    if (!response.data.isValid()) {
-        showMessage(msgCannotLoadQmlStack("No result obtained."), LogError);
-        return;
-    }
-    // Prepend QML stack frames to existing C++ stack frames.
-    QString stackData = response.data["value"].data();
-    const int index = stackData.indexOf("stack=");
-    if (index == -1) {
-        showMessage(msgCannotLoadQmlStack("Malformed result."), LogError);
-        return;
-    }
-    stackData.remove(0, index);
-    stackData.replace("\\\"", "\"");
-    GdbMi stackMi;
-    stackMi.fromString(stackData);
-    const int qmlFrameCount = stackMi.childCount();
-    if (!qmlFrameCount) {
-        showMessage(msgCannotLoadQmlStack("No stack frames obtained."), LogError);
-        return;
-    }
-    QList<StackFrame> qmlFrames;
-    qmlFrames.reserve(qmlFrameCount);
-    for (int i = 0; i < qmlFrameCount; ++i)
-        qmlFrames.append(StackFrame::parseFrame(stackMi.childAt(i), runParameters()));
-    stackHandler()->prependFrames(qmlFrames);
-}
-
 DebuggerCommand GdbEngine::stackCommand(int depth)
 {
     DebuggerCommand cmd("fetchStack");

src/plugins/debugger/gdb/gdbengine.h

@@ -360,9 +360,8 @@ protected:
     void handleThreadNames(const DebuggerResponse &response);
     DebuggerCommand stackCommand(int depth);
     void reloadStack();
-    virtual void reloadFullStack() override;
-    virtual void loadAdditionalQmlStack() override;
-    void handleQmlStackTrace(const DebuggerResponse &response);
+    void reloadFullStack() override;
+    void loadAdditionalQmlStack() override;
     int currentFrame() const;
 
     //

src/plugins/debugger/qml/qmlcppengine.cpp

@@ -779,5 +779,11 @@ void QmlCppEngine::setActiveEngine(DebuggerEngine *engine)
     updateViews();
 }
 
+void QmlCppEngine::loadAdditionalQmlStack()
+{
+    if (m_cppEngine)
+        m_cppEngine->loadAdditionalQmlStack();
+}
+
 } // namespace Internal
 } // namespace Debugger

src/plugins/debugger/qml/qmlcppengine.h

@@ -123,6 +123,7 @@ protected:
 
     void notifyInferiorSetupOk() override;
     void notifyEngineRemoteServerRunning(const QString &, int pid) override;
+    void loadAdditionalQmlStack() override;
 
 private:
     void engineStateChanged(DebuggerState newState);