/// <summary>
/// Evaluates an LLDB expression. It decides which expression evaluation method to use
/// (e.g. LLDB, lldb-eval, path expression, etc.) depending on the Stadia SDK settings and
/// the input |expression|. It doesn't support format specifiers, only expressions that
/// can be directly evaluated in the LLDB environment.
/// </summary>
/// <param name="expression">The expression to be evaluated.</param>
/// <param name="variable">The evaluation context.</param>
/// <param name="natvisScope">The Natvis tokens to be resolved before evaluation.</param>
/// <param name="displayName">The display name given to the result. If null the underlying
/// debugger's context specific name is used.</param>
/// <returns>The expression result.</returns>
async Task <IVariableInformation> EvaluateLldbExpressionAsync(VsExpression expression,
IVariableInformation variable,
NatvisScope natvisScope,
string displayName)
{
ExpressionEvaluationStrategy strategy = _extensionOptions.ExpressionEvaluationStrategy;
var stepsRecorder = new ExpressionEvaluationRecorder.StepsRecorder(_timeSource);
long startTimestampUs = _timeSource.GetTimestampUs();
IVariableInformation variableInformation =
await EvaluateLldbExpressionWithMetricsAsync(
expression, variable, natvisScope, displayName, strategy, stepsRecorder);
// Evaluating a context variable will just return the reference to it. Because of
// deferred evaluation of display values, some values could be incorrectly displayed
// (in the case a context variable was changed in between two expression evaluations).
// In order to prevent this, we create a copy of result if the expression was simply
// a context variable.
if (natvisScope.IsContextVariable(expression.Value))
{
variableInformation = variableInformation.Clone(expression.FormatSpecifier);
}
long endTimestampUs = _timeSource.GetTimestampUs();
_expressionEvaluationRecorder.Record(strategy, ExpressionEvaluationContext.VALUE,
stepsRecorder, startTimestampUs, endTimestampUs,
variable.Id);
return(variableInformation);
}
async Task <RemoteValue> CreateValueFromExpressionAsync(string expression)
{
var stepsRecorder = new ExpressionEvaluationRecorder.StepsRecorder(_timeSource);
long startTimestampUs = _timeSource.GetTimestampUs();
RemoteValue remoteValue =
await CreateValueFromExpressionWithMetricsAsync(expression, stepsRecorder);
long endTimestampUs = _timeSource.GetTimestampUs();
_expressionEvaluationRecorder.Record(_expressionEvaluationStrategy,
_expressionEvaluationContext, stepsRecorder,
startTimestampUs, endTimestampUs);
return(remoteValue);
}
public void RecordSingleEventWithTwoStepsTest()
{
const ExpressionEvaluationStrategy strategySource = ExpressionEvaluationStrategy.LLDB;
const ExpressionEvaluationContext contextSource = ExpressionEvaluationContext.FRAME;
var stepsRecorder = new ExpressionEvaluationRecorder.StepsRecorder(_timeSource);
using (Step step = stepsRecorder.NewStep(ExpressionEvaluationEngine.LLDB_VARIABLE_PATH))
{
step.Finalize(LLDBErrorCode.ERROR);
}
using (Step step = stepsRecorder.NewStep(ExpressionEvaluationEngine.LLDB))
{
step.Finalize(LLDBErrorCode.OK);
}
const long startTimestampUs = 750;
const long endTimestampUs = 21562;
_expressionEvaluationRecorder.Record(strategySource, contextSource, stepsRecorder,
startTimestampUs, endTimestampUs);
// Get a copy of the batch summary sent to batchEventAggregator so we can verify
// that it matches the one being sent to metrics.
ExpressionEvaluationBatchSummary batchSummary = null;
_batchEventAggregator.BatchSummaryReady += (_, newSummary) => batchSummary = newSummary;
_timer.Increment(_minimumBatchSeparationMilliseconds);
_eventScheduler.Increment(_minimumBatchSeparationMilliseconds);
const ExpressionEvaluation.Types.Strategy strategyExpected =
ExpressionEvaluation.Types.Strategy.Lldb;
const ExpressionEvaluation.Types.Context contextExpected = ExpressionEvaluation.Types
.Context.Frame;
Assert.AreEqual(1, batchSummary.Proto.ExpressionEvaluations.Count);
ExpressionEvaluation received = batchSummary.Proto.ExpressionEvaluations[0];
Assert.Multiple(() =>
{
Assert.AreEqual(strategyExpected, received.Strategy);
Assert.AreEqual(contextExpected, received.Context);
Assert.NotNull(received.EvaluationSteps);
Assert.AreEqual(2, received.EvaluationSteps.Count);
Assert.AreEqual(startTimestampUs, received.StartTimestampMicroseconds);
Assert.AreEqual(endTimestampUs, received.EndTimestampMicroseconds);
Assert.Null(received.NatvisValueId);
});
const ExpressionEvaluationStep.Types.Engine firstStepEngineExpected =
ExpressionEvaluationStep.Types.Engine.LldbVariablePath;
const ExpressionEvaluationStep.Types.EngineResult firstStepEngineResultExpected =
ExpressionEvaluationStep.Types.EngineResult.LldbError;
const ExpressionEvaluationStep.Types.Engine secondStepEngineExpected =
ExpressionEvaluationStep.Types.Engine.Lldb;
const ExpressionEvaluationStep.Types.EngineResult secondStepEngineResultExpected =
ExpressionEvaluationStep.Types.EngineResult.LldbOk;
ExpressionEvaluationStep firstStep = received.EvaluationSteps[0];
ExpressionEvaluationStep secondStep = received.EvaluationSteps[1];
Assert.Multiple(() =>
{
Assert.AreEqual(firstStepEngineExpected, firstStep.Engine);
Assert.AreEqual(firstStepEngineResultExpected, firstStep.Result);
Assert.AreEqual(1, firstStep.DurationMicroseconds);
Assert.AreEqual(secondStepEngineExpected, secondStep.Engine);
Assert.AreEqual(secondStepEngineResultExpected, secondStep.Result);
Assert.AreEqual(1, secondStep.DurationMicroseconds);
});
_metrics.Received(1)
.RecordEvent(DeveloperEventType.Types.Type.VsiDebugExpressionEvaluationBatch,
new DeveloperLogEvent
{
DebugExpressionEvaluationBatch = batchSummary.Proto,
StatusCode = DeveloperEventStatus.Types.Code.Success
});
}