/// <summary>
/// Tries to filter a given workspace definition by reusing information from the previous BuildXL invocation.
/// </summary>
/// <returns>
/// 1. Failure if the error occurred during parsing/binding one of the changed specs.
/// 2. Result(null) when the filtering failed due to symbols mismatch or due to another reason.
/// 3. Result(WorkspaceDefinition) when the filtering succeeded.
/// </returns>
/// <remarks>
/// If the previous binding information can be reused, then the set of specs that are safe to use as public facades + serialized AST
/// are identified as well
/// </remarks>
private async Task <FilteredWorkspaceDefinition> TryFilterWorkspaceDefinitionIncrementallyAsync(
List <string> changedFiles,
IWorkspaceProvider workspaceProvider,
WorkspaceDefinition workspaceDefinition,
EvaluationFilter evaluationFilter)
{
Logger.TryingToReuseFrontEndSnapshot(LoggingContext);
// TODO: potentially, we could check the number of changes compared to the workspace definition size.
// If the number of changes is too big, maybe we should go into the full parse mode.
// But we need to check the perf implications before making this decision.
var changedSpecs = changedFiles.Select(
p =>
{
var fullPath = AbsolutePath.Create(FrontEndContext.PathTable, p);
var containingModule = workspaceDefinition.TryGetModuleDefinition(fullPath);
return(new SpecWithOwningModule(fullPath, containingModule));
}).ToArray();
// Need to check if the spec does not belong to the current workspace
// or the changed spec belongs to the prelude.
foreach (var changedSpec in changedSpecs)
{
if (changedSpec.OwningModule == null)
{
Logger.FailToReuseFrontEndSnapshot(
LoggingContext,
I($"Changed spec file '{changedSpec.Path.ToString(FrontEndContext.PathTable)}' is not part of the computed workspace."));
return(FilteredWorkspaceDefinition.CanNotFilter());
}
if (changedSpec.OwningModule.Descriptor == workspaceDefinition.PreludeModule.Descriptor)
{
Logger.FailToReuseFrontEndSnapshot(
LoggingContext,
I($"Changed spec file '{changedSpec.Path.ToString(FrontEndContext.PathTable)}' is part of the prelude."));
return(FilteredWorkspaceDefinition.CanNotFilter());
}
}
// Getting the snapshot from the previous run.
// Binding snapshot contains all the specs as well as all the configuration files.
// Need to adjust the count.
var expectedNumberOfSpecs = workspaceDefinition.SpecCount + (workspaceProvider.GetConfigurationModule()?.Specs.Count ?? 0);
var snapshot = FrontEndArtifactManager.TryLoadFrontEndSnapshot(expectedNumberOfSpecs);
if (snapshot == null)
{
// The error message was already logged.
return(FilteredWorkspaceDefinition.CanNotFilter());
}
// Parsing and binding all the changed specs.
var possibleParseResult = await workspaceProvider.ParseAndBindSpecsAsync(changedSpecs);
var firstFailure = LogParseOrBindingErrorsIfAny(possibleParseResult);
if (firstFailure != null)
{
// This is actual failure.
// Instead of switching to the full mode, we can actually stop here.
return(FilteredWorkspaceDefinition.Error(firstFailure));
}
// Snapshot is valid and parse/binding is completed successfully.
var snapshotState = GetSnapshotReuseState(possibleParseResult, snapshot);
if (snapshotState.State == SnapshotState.NoMatch)
{
// NoMatch is returned if the snapshot is unavailable.
if (snapshotState.SpecsWithIncompatiblePublicSurface.Count != 0)
{
Logger.FailToReuseFrontEndSnapshot(
LoggingContext,
I($"Spec file '{snapshotState.SpecsWithIncompatiblePublicSurface.First().Path.AbsolutePath}' changed its binding symbols."));
}
return(FilteredWorkspaceDefinition.CanNotFilter());
}
// Changed file could get different symbols.
// Need to re-save it within the front-end snapshot.
UpdateAndSaveSnapshot(possibleParseResult, snapshot);
var snapshotProvider = new SnapshotBasedSpecProvider(snapshot);
// Now we know exactly which are all the files that need to go through parsing/type checking/AST conversion. So we
// inform that to the artifact manager so the public surface and AST serialization
// can be resued for the rest, if available.
// Observe these set of files are not reflecting a potential user filter, but that's fine. If there is a dirty spec
// that is outside of the filter, that spec won't be requested by the workspace anyway
NotifyDirtySpecsForPublicFacadeAndAstReuse(
snapshotProvider,
workspaceDefinition,
changedSpecs.Select(f => f.Path).ToList());
// The fingerprints for all changed specs are still the same,
// so we can filter the workspace definition provided that the filter allows it.
if (snapshotState.State == SnapshotState.FullMatch)
{
var filter = new WorkspaceFilter(FrontEndContext.PathTable);
var filteredWorkspace = evaluationFilter.CanPerformPartialEvaluationScript(PrimaryConfigFile)
? filter.FilterWorkspaceDefinition(workspaceDefinition, evaluationFilter, snapshotProvider)
: workspaceDefinition.Modules;
return(FilteredWorkspaceDefinition.Filter(new WorkspaceDefinition(filteredWorkspace, workspaceDefinition.PreludeModule)));
}
// Specs are not the same, but we would be able to load public facades for all unaffected specs.
var dirtySpecNames = string.Join(
", ",
snapshotState.SpecsWithTheSamePublicSurface.Take(10).Select(p => Path.GetFileName(p.Path.AbsolutePath)));
Logger.FailedToFilterWorkspaceDefinition(
LoggingContext,
I($"{dirtySpecNames} changed one or more declarations."));
return(FilteredWorkspaceDefinition.CanNotFilter());
}
/// <inheritdoc />
public Task <Possible <ISourceFile>[]> ParseAndBindSpecsAsync(SpecWithOwningModule[] specs)
{
return(m_decoratee.ParseAndBindSpecsAsync(specs));
}