public static void Patch(int version, EngineIntrinsics context, PSHostUserInterface ui)
{
Clear();
var uiFieldName = version >= 7 ? "_externalUI" : "externalUI";
// we get InternalHostUserInterface, grab external ui from that and replace it with ours
var externalUIField = ui.GetType().GetField(uiFieldName, BindingFlags.Instance | BindingFlags.NonPublic);
var externalUI = (PSHostUserInterface)externalUIField.GetValue(ui);
// replace it with out patched up UI that writes to profiler on debug
externalUIField.SetValue(ui, new ProfilerUI(externalUI));
ResetUI = () =>
{
externalUIField.SetValue(ui, externalUI);
};
// getting MethodInfo of context._context.Debugger.TraceLine
var bf = BindingFlags.NonPublic | BindingFlags.Instance;
var contextInternal = context.GetType().GetField("_context", bf).GetValue(context);
var debugger = contextInternal.GetType().GetProperty("Debugger", bf).GetValue(contextInternal);
var debuggerType = debugger.GetType();
var callStackField = debuggerType.GetField("_callStack", BindingFlags.Instance | BindingFlags.NonPublic);
var _callStack = callStackField.GetValue(debugger);
var callStackType = _callStack.GetType();
var countProperty = callStackType.GetProperty("Count", BindingFlags.Instance | BindingFlags.NonPublic);
var getCount = countProperty.GetMethod;
var empty = new object[0];
var stack = callStackField.GetValue(debugger);
var initialLevel = (int)getCount.Invoke(stack, empty);
var lastFunctionContextMethod = callStackType.GetMethod("LastFunctionContext", BindingFlags.Instance | BindingFlags.NonPublic);
object functionContext1 = lastFunctionContextMethod.Invoke(callStackField.GetValue(debugger), empty);
var functionContextType = functionContext1.GetType();
var scriptBlockField = functionContextType.GetField("_scriptBlock", BindingFlags.Instance | BindingFlags.NonPublic);
var currentPositionProperty = functionContextType.GetProperty("CurrentPosition", BindingFlags.Instance | BindingFlags.NonPublic);
var scriptBlock1 = (ScriptBlock)scriptBlockField.GetValue(functionContext1);
var extent1 = (IScriptExtent)currentPositionProperty.GetValue(functionContext1);
TraceLine = () =>
{
var callStack = callStackField.GetValue(debugger);
var level = (int)getCount.Invoke(callStack, empty) - initialLevel;
object functionContext = lastFunctionContextMethod.Invoke(callStack, empty);
var scriptBlock = (ScriptBlock)scriptBlockField.GetValue(functionContext);
var extent = (IScriptExtent)currentPositionProperty.GetValue(functionContext);
Trace(extent, scriptBlock, level);
};
// Add another event to the top apart from the scriptblock invocation
// in Trace-ScriptInternal, this makes it more consistently work on first
// run. Without this, the triggering line sometimes does not show up as 99.9%
TraceLine();
}
/// <summary>
/// Enable tracing by patch the current session by replacing the UI host with another that triggers tracing on every statement. Set-PSDebug -Trace 1 needs to be called before this, and Set-PSDebug -Off needs to be called after Unpatch.
/// </summary>
/// <param name="powerShellVersion">Major PSVersion that is used `$PSVersionTable.PSVersion.Major`</param>
/// <param name="context">ExecutionContext to be used `$ExecutionContext`</param>
/// <param name="ui">UIHost to be replaced. `$host.UI`</param>
/// <param name="tracer">The tracer to be used. For example ProfilerTracer.</param>
public static void Patch(int powerShellVersion, EngineIntrinsics context, PSHostUserInterface ui, ITracer tracer)
{
if (context is null)
{
throw new ArgumentNullException(nameof(context));
}
if (ui is null)
{
throw new ArgumentNullException(nameof(ui));
}
Tracer1 = tracer ?? throw new ArgumentNullException(nameof(tracer));
var uiFieldName = powerShellVersion >= 6 ? "_externalUI" : "externalUI";
// we get InternalHostUserInterface, grab external ui from that and replace it with ours
var externalUIField = ui.GetType().GetField(uiFieldName, BindingFlags.Instance | BindingFlags.NonPublic);
var externalUI = (PSHostUserInterface)externalUIField.GetValue(ui);
// replace it with out patched up UI that writes to profiler on debug
externalUIField.SetValue(ui, new TracerHostUI(externalUI, (message) => TraceLine(message, false)));
ResetUI = () =>
{
externalUIField.SetValue(ui, externalUI);
};
// getting MethodInfo of context._context.Debugger.TraceLine
var bf = BindingFlags.NonPublic | BindingFlags.Instance;
var contextInternal = context.GetType().GetField("_context", bf).GetValue(context);
var debugger = contextInternal.GetType().GetProperty("Debugger", bf).GetValue(contextInternal);
var debuggerType = debugger.GetType();
var callStackField = debuggerType.GetField("_callStack", BindingFlags.Instance | BindingFlags.NonPublic);
var _callStack = callStackField.GetValue(debugger);
var callStackType = _callStack.GetType();
var countBindingFlags = BindingFlags.Instance | BindingFlags.NonPublic;
if (powerShellVersion == 3)
{
// in PowerShell 3 callstack is List<CallStackInfo> not a struct CallStackList
// Count is public property
countBindingFlags = BindingFlags.Instance | BindingFlags.Public;
}
var countProperty = callStackType.GetProperty("Count", countBindingFlags);
var getCount = countProperty.GetMethod;
var empty = new object[0];
var stack = callStackField.GetValue(debugger);
var initialLevel = (int)getCount.Invoke(stack, empty);
if (powerShellVersion == 3)
{
// we do the same operation as in the TraceLineAction below, but here
// we resolve the static things like types and properties, and then in the
// action we just use them to get the live data without the overhead of looking
// up properties all the time. This might be internally done in the reflection code
// did not measure the impact, and it is probably done for us in the reflection api itself
// in modern verisons of runtime
var callStack1 = callStackField.GetValue(debugger);
var callStackList1 = (NonGeneric.IList)callStack1;
var level1 = callStackList1.Count - initialLevel;
var last1 = callStackList1[callStackList1.Count - 1];
var lastType = last1.GetType();
var functionContextProperty = lastType.GetProperty("FunctionContext", BindingFlags.NonPublic | BindingFlags.Instance);
var functionContext1 = functionContextProperty.GetValue(last1);
var functionContextType = functionContext1.GetType();
var scriptBlockField = functionContextType.GetField("_scriptBlock", BindingFlags.Instance | BindingFlags.NonPublic);
var currentPositionProperty = functionContextType.GetProperty("CurrentPosition", BindingFlags.Instance | BindingFlags.NonPublic);
var scriptBlock1 = (ScriptBlock)scriptBlockField.GetValue(functionContext1);
var extent1 = (IScriptExtent)currentPositionProperty.GetValue(functionContext1);
GetTraceLineInfo = () =>
{
var callStack = callStackField.GetValue(debugger);
var callStackList = (NonGeneric.IList)callStack;
var level = callStackList.Count - initialLevel;
var last = callStackList[callStackList.Count - 1];
var functionContext = functionContextProperty.GetValue(last);
var scriptBlock = (ScriptBlock)scriptBlockField.GetValue(functionContext);
var extent = (IScriptExtent)currentPositionProperty.GetValue(functionContext);
return(new TraceLineInfo(extent, scriptBlock, level));
};
}
else
{
var lastFunctionContextMethod = callStackType.GetMethod("LastFunctionContext", BindingFlags.Instance | BindingFlags.NonPublic);
object functionContext1 = lastFunctionContextMethod.Invoke(callStackField.GetValue(debugger), empty);
var functionContextType = functionContext1.GetType();
var scriptBlockField = functionContextType.GetField("_scriptBlock", BindingFlags.Instance | BindingFlags.NonPublic);
var currentPositionProperty = functionContextType.GetProperty("CurrentPosition", BindingFlags.Instance | BindingFlags.NonPublic);
var scriptBlock1 = (ScriptBlock)scriptBlockField.GetValue(functionContext1);
var extent1 = (IScriptExtent)currentPositionProperty.GetValue(functionContext1);
GetTraceLineInfo = () =>
{
var callStack = callStackField.GetValue(debugger);
var level = (int)getCount.Invoke(callStack, empty) - initialLevel;
object functionContext = lastFunctionContextMethod.Invoke(callStack, empty);
var scriptBlock = (ScriptBlock)scriptBlockField.GetValue(functionContext);
var extent = (IScriptExtent)currentPositionProperty.GetValue(functionContext);
return(new TraceLineInfo(extent, scriptBlock, level));
};
}
#pragma warning disable CS0618 // Type or member is obsolete
IsEnabled = true;
#pragma warning restore CS0618 // Type or member is obsolete
// Add another event to the top apart from the scriptblock invocation
// in Trace-ScriptInternal, this makes it more consistently work on first
// run. Without this, the triggering line sometimes does not show up as 99.9%
TraceLine();
}
