Debugger: Implement "Load QML Stack" feature for LLDB

Fixes: QTCREATORBUG-25554
Change-Id: Ieafa22581c294d9b993efe077354750a8f986424
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

share/qtcreator/debugger/lldbbridge.py

@@ -1107,13 +1107,53 @@ class Dumper(DumperBase):
             return
 
         isNativeMixed = int(args.get('nativemixed', 0))
+        extraQml = int(args.get('extraqml', '0'))
 
         limit = args.get('stacklimit', -1)
         (n, isLimited) = (limit, True) if limit > 0 else (thread.GetNumFrames(), False)
         self.currentCallContext = None
         result = 'stack={current-thread="%d"' % thread.GetThreadID()
         result += ',frames=['
-        for i in range(n):
+
+        ii = 0
+        if extraQml:
+            ns = self.qtNamespace()
+            needle = self.qtNamespace() + 'QV4::ExecutionEngine'
+            pats = [
+                    '{0}qt_v4StackTraceForEngine((void*)0x{1:x})',
+                    '{0}qt_v4StackTrace((({0}QV4::ExecutionEngine *)0x{1:x})->currentContext())',
+                    '{0}qt_v4StackTrace((({0}QV4::ExecutionEngine *)0x{1:x})->currentContext)',
+                   ]
+            done = False
+            while ii < n and not done:
+                res = None
+                frame = thread.GetFrameAtIndex(ii)
+                for variable in frame.GetVariables(True, True, False, True):
+                    if not variable.GetType().IsPointerType():
+                        continue
+                    derefvar = variable.Dereference()
+                    if derefvar.GetType().GetName() != needle:
+                        continue
+                    addr = derefvar.GetLoadAddress()
+                    for pat in pats:
+                        exp = pat.format(ns, addr)
+                        val = frame.EvaluateExpression(exp)
+                        err = val.GetError()
+                        res = str(val)
+                        if err.Fail():
+                            continue
+                        pos = res.find('"stack=[')
+                        if pos == -1:
+                            continue
+                        res = res[pos + 8:-2]
+                        res = res.replace('\\\"', '\"')
+                        res = res.replace('func=', 'function=')
+                        result += res
+                        done = True
+                        break
+                ii += 1
+
+        for i in range(n - ii):
             frame = thread.GetFrameAtIndex(i)
             if not frame.IsValid():
                 isLimited = False

src/plugins/debugger/lldb/lldbengine.cpp

@@ -715,27 +715,6 @@ void LldbEngine::updateAll()
     runCommand(cmd);
 }
 
-void LldbEngine::reloadFullStack()
-{
-    fetchStack(-1);
-}
-
-void LldbEngine::fetchStack(int limit)
-{
-    DebuggerCommand cmd("fetchStack");
-    cmd.arg("nativemixed", isNativeMixedActive());
-    cmd.arg("stacklimit", limit);
-    cmd.arg("context", stackHandler()->currentFrame().context);
-    cmd.callback = [this](const DebuggerResponse &response) {
-        const GdbMi &stack = response.data["stack"];
-        const bool isFull = !stack["hasmore"].toInt();
-        stackHandler()->setFramesAndCurrentIndex(stack["frames"], isFull);
-        activateFrame(stackHandler()->currentIndex());
-    };
-    runCommand(cmd);
-}
-
-
 //////////////////////////////////////////////////////////////////////
 //
 // Watch specific stuff
@@ -980,6 +959,33 @@ void LldbEngine::reloadDebuggingHelpers()
     updateAll();
 }
 
+void LldbEngine::loadAdditionalQmlStack()
+{
+    fetchStack(-1, true);
+}
+
+void LldbEngine::reloadFullStack()
+{
+    fetchStack(-1, false);
+}
+
+void LldbEngine::fetchStack(int limit, bool extraQml)
+{
+    DebuggerCommand cmd("fetchStack");
+    cmd.arg("nativemixed", isNativeMixedActive());
+    cmd.arg("stacklimit", limit);
+    cmd.arg("context", stackHandler()->currentFrame().context);
+    cmd.arg("extraqml", int(extraQml));
+    cmd.callback = [this](const DebuggerResponse &response) {
+        const GdbMi &stack = response.data["stack"];
+        const bool isFull = !stack["hasmore"].toInt();
+        stackHandler()->setFramesAndCurrentIndex(stack["frames"], isFull);
+        activateFrame(stackHandler()->currentIndex());
+    };
+    runCommand(cmd);
+}
+
+
 void LldbEngine::fetchDisassembler(DisassemblerAgent *agent)
 {
     QPointer<DisassemblerAgent> p(agent);
@@ -1090,7 +1096,8 @@ bool LldbEngine::hasCapability(unsigned cap) const
         | OperateByInstructionCapability
         | RunToLineCapability
         | WatchComplexExpressionsCapability
-        | MemoryAddressCapability))
+        | MemoryAddressCapability
+        | AdditionalQmlStackCapability))
         return true;
 
     if (runParameters().startMode == AttachToCore)

src/plugins/debugger/lldb/lldbengine.h

@@ -101,6 +101,7 @@ private:
     void reloadSourceFiles() override {}
     void reloadFullStack() override;
     void reloadDebuggingHelpers() override;
+    void loadAdditionalQmlStack() override;
     void fetchDisassembler(Internal::DisassemblerAgent *) override;
 
     void setRegisterValue(const QString &name, const QString &value) override;
@@ -125,7 +126,7 @@ private:
     void updateAll() override;
     void doUpdateLocals(const UpdateParameters &params) override;
     void updateBreakpointData(const Breakpoint &bp, const GdbMi &bkpt, bool added);
-    void fetchStack(int limit);
+    void fetchStack(int limit, bool alsoQml = false);
 
     void runCommand(const DebuggerCommand &cmd) override;
     void debugLastCommand() override;