DBG+BRIDGE+GUI: warn when trying to render a graph with more than 5000 nodes

(closes #1321)

src/bridge/bridgemain.cpp

@@ -1552,9 +1552,9 @@ BRIDGE_IMPEXP void GuiFocusView(int hWindow)
     _gui_sendmessage(GUI_FOCUS_VIEW, (void*)hWindow, nullptr);
 }
 
-BRIDGE_IMPEXP void GuiLoadGraph(BridgeCFGraphList* graph, duint addr)
+BRIDGE_IMPEXP bool GuiLoadGraph(BridgeCFGraphList* graph, duint addr)
 {
-    _gui_sendmessage(GUI_LOAD_GRAPH, graph, (void*)addr);
+    return !!_gui_sendmessage(GUI_LOAD_GRAPH, graph, (void*)addr);
 }
 
 BRIDGE_IMPEXP duint GuiGraphAt(duint addr)

src/bridge/bridgemain.h

@@ -1266,7 +1266,7 @@ BRIDGE_IMPEXP void GuiFocusView(int hWindow);
 BRIDGE_IMPEXP bool GuiIsUpdateDisabled();
 BRIDGE_IMPEXP void GuiUpdateEnable(bool updateNow);
 BRIDGE_IMPEXP void GuiUpdateDisable();
-BRIDGE_IMPEXP void GuiLoadGraph(BridgeCFGraphList* graph, duint addr);
+BRIDGE_IMPEXP bool GuiLoadGraph(BridgeCFGraphList* graph, duint addr);
 BRIDGE_IMPEXP duint GuiGraphAt(duint addr);
 BRIDGE_IMPEXP void GuiUpdateGraphView();
 BRIDGE_IMPEXP void GuiDisableLog();

src/dbg/commands/cmd-gui.cpp

@@ -126,7 +126,8 @@ bool cbInstrGraph(int argc, char* argv[])
             return false;
         }
         auto graphList = graph->ToGraphList();
-        GuiLoadGraph(&graphList, sel);
+        if(!GuiLoadGraph(&graphList, sel))
+            return false;
     }
     GuiUpdateAllViews();
     GuiFocusView(GUI_GRAPH);

src/gui/Src/Bridge/Bridge.cpp

@@ -684,7 +684,7 @@ void* Bridge::processMessage(GUIMSG type, void* param1, void* param2)
     {
         BridgeResult result;
         emit loadGraph((BridgeCFGraphList*)param1, duint(param2));
-        result.Wait();
+        return (void*)result.Wait();
     }
     break;
 

src/gui/Src/Gui/CPUDisassembly.cpp

@@ -1904,8 +1904,8 @@ void CPUDisassembly::setEncodeTypeSlot()
 
 void CPUDisassembly::graphSlot()
 {
-    DbgCmdExecDirect(QString("graph %1").arg(ToPtrString(rvaToVa(getSelectionStart()))).toUtf8().constData());
-    emit displayGraphWidget();
+    if(DbgCmdExecDirect(QString("graph %1").arg(ToPtrString(rvaToVa(getSelectionStart()))).toUtf8().constData()))
+        emit displayGraphWidget();
 }
 
 void CPUDisassembly::togglePreviewSlot()

src/gui/Src/Gui/DisassemblerGraphView.cpp

@@ -1617,12 +1617,24 @@ void DisassemblerGraphView::loadCurrentGraph()
 
 void DisassemblerGraphView::loadGraphSlot(BridgeCFGraphList* graphList, duint addr)
 {
+    auto nodeCount = graphList->nodes.count;
+    if(nodeCount > 5000) //TODO: add configuration
+    {
+        auto title = tr("Large number of nodes");
+        auto message = tr("The graph you are trying to render has a large number of nodes (%1). This can cause x64dbg to hang or crash. It is recommended to save your data before you continue.\n\nDo you want to continue rendering this graph?").arg(nodeCount);
+        if(QMessageBox::question(this, title, message, QMessageBox::Yes, QMessageBox::No | QMessageBox::Default) == QMessageBox::No)
+        {
+            Bridge::getBridge()->setResult(0);
+            return;
+        }
+    }
+
     currentGraph = BridgeCFGraph(graphList, true);
     currentBlockMap.clear();
     this->cur_instr = addr ? addr : this->function;
     this->forceCenter = true;
     loadCurrentGraph();
-    Bridge::getBridge()->setResult();
+    Bridge::getBridge()->setResult(1);
 }
 
 void DisassemblerGraphView::graphAtSlot(duint addr)