Add Exception Stacks view when viewing a .nettrace with exceptions (#2223)

* Initial plan for issue

* Add Exception Stacks view support for .nettrace files

Co-authored-by: brianrob <[email protected]>

* Fix OnlyManagedCodeStacks setting for Exceptions to respect hasUniversalSystem

Co-authored-by: brianrob <[email protected]>

* Update OnlyManagedCodeStacks to use m_supportsProcesses instead of hasUniversalSystem

Co-authored-by: brianrob <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: brianrob <[email protected]>

Author: Copilot

src/PerfView/PerfViewData.cs

@@ -9461,6 +9461,7 @@ protected override Action<Action> OpenImpl(Window parentWindow, StatusBar worker
             bool hasAspNetCoreHosting = false;
             bool hasContention = false;
             bool hasWaitHandle = false;
+            bool hasExceptions = false;
             bool hasUniversalSystem = false;
             bool hasUniversalCPU = false;
             if (m_traceLog != null)
@@ -9516,6 +9517,10 @@ protected override Action<Action> OpenImpl(Window parentWindow, StatusBar worker
                     {
                         hasWaitHandle = true;
                     }
+                    else if (eventStats.EventName.StartsWith("Exception/Start"))
+                    {
+                        hasExceptions = true;
+                    }
                     else if (eventStats.ProviderGuid == UniversalSystemTraceEventParser.ProviderGuid)
                     {
                         hasUniversalSystem = true;
@@ -9610,6 +9615,11 @@ protected override Action<Action> OpenImpl(Window parentWindow, StatusBar worker
                 {
                     advanced.AddChild(new PerfViewStackSource(this, "WaitHandleWait"));
                 }
+
+                if (hasExceptions)
+                {
+                    advanced.AddChild(new PerfViewStackSource(this, "Exceptions"));
+                }
             }
 
             if (memory.Children.Count > 0)
@@ -9969,6 +9979,43 @@ protected internal override StackSource OpenStackSourceImpl(string streamName, T
                             return null;
                         }
 
+                        return stackSource;
+                    }
+                case "Exceptions":
+                    {
+                        var eventLog = GetTraceLog(log);
+
+                        var stackSource = new MutableTraceEventStackSource(eventLog);
+                        // EventPipe currently only has managed code stacks.
+                        stackSource.OnlyManagedCodeStacks = !m_supportsProcesses;
+                        stackSource.ShowUnknownAddresses = App.CommandLineArgs.ShowUnknownAddresses;
+                        stackSource.ShowOptimizationTiers = App.CommandLineArgs.ShowOptimizationTiers;
+
+                        TraceEvents events = eventLog.Events;
+
+                        if (startRelativeMSec != 0 || endRelativeMSec != double.PositiveInfinity)
+                        {
+                            events = events.FilterByTime(startRelativeMSec, endRelativeMSec);
+                        }
+
+                        var eventSource = events.GetSource();
+                        var sample = new StackSourceSample(stackSource);
+
+                        eventSource.Clr.ExceptionStart += delegate (ExceptionTraceData data)
+                        {
+                            sample.Metric = 1;
+                            sample.TimeRelativeMSec = data.TimeStampRelativeMSec;
+
+                            // Create a call stack that ends with the 'throw'
+                            var nodeName = "Throw(" + data.ExceptionType + ") " + data.ExceptionMessage;
+                            var nodeIndex = stackSource.Interner.FrameIntern(nodeName);
+                            sample.StackIndex = stackSource.Interner.CallStackIntern(nodeIndex, stackSource.GetCallStack(data.CallStackIndex(), data));
+                            stackSource.AddSample(sample);
+                        };
+
+                        eventSource.Process();
+                        stackSource.DoneAddingSamples();
+
                         return stackSource;
                     }
             }