private Task<ITargetDescription> _orderTargetDescription(PreflightResult result, FileInfo candidate, CancellationToken token, SelfAssemblyMode mode)
{
if (candidate == null)
throw new ArgumentNullException("candidate");
return _targetCreationCache.GetOrAdd(candidate.FullName,
async (key, actualToken) =>
{
var src = Source.FromFile(candidate, Encoding);
await Task.Yield();
await _addToSearchPaths(candidate, actualToken);
return await _performCreateTargetDescription(result, src, actualToken, mode);
}, token);
}
private async Task<ITargetDescription> _performCreateTargetDescription(PreflightResult result, ISource source, CancellationToken token, SelfAssemblyMode mode)
{
Debug.Assert(result.ErrorMessage == null, "TargetDescription ordered despite the preflight result containing errors.");
Debug.Assert(result.References.All(r => r.ErrorMessage == null), "TargetDescription ordered despite the preflight result containing errors.");
RefSpec[] refSpecs;
switch (mode)
{
case SelfAssemblyMode.RecurseIntoFileSystem:
var refSpecResolveTasks =
result.References
.Select(r => _resolveRefSpec(r, token, mode))
.ToArray();
await Task.WhenAll(refSpecResolveTasks);
refSpecs = refSpecResolveTasks.Select(t => t.Result).ToArray();
break;
case SelfAssemblyMode.RegisterOnly:
refSpecs = result.References.Select(_forbidFileRefSpec).ToArray();
break;
default:
throw new ArgumentOutOfRangeException("mode", mode, Resources.SelfAssemblingPlan_performCreateTargetDescription_mode);
}
var buildMessages = refSpecs.Where(t => t.ErrorMessage != null).Select(
s =>
{
Debug.Assert(s.ErrorMessage != null);
// ReSharper disable PossibleNullReferenceException,AssignNullToNotNullAttribute
var refPosition = new SourcePosition(
s.ResolvedPath != null ? s.ResolvedPath.ToString()
: result.Path != null ? result.Path.ToString()
: NoSourcePosition.MissingFileName, 0, 0);
return Message.Error(s.ErrorMessage, refPosition, MessageClasses.SelfAssembly);
// ReSharper restore PossibleNullReferenceException,AssignNullToNotNullAttribute
});
// Assemble dependencies, including standard library (unless suppressed)
var deps = refSpecs.Where(r => r.ModuleName != null).Select(r => r.ModuleName);
if (!result.SuppressStandardLibrary)
deps = deps.Append(StandardLibrary);
var reportedFileName =
result.Path != null ? result.Path.ToString()
: result.ModuleName != null ? result.ModuleName.Id + ".pxs"
: null;
// Typically, duplicate requests are caught much earlier (based on full file paths)
// But if the user of this self assembling build plan manually adds descriptions
// that can also be found on the file system, that conflict can in some situations
// not be detected until full preflight is done.
// This GetOrAdd is our last line of defense against that scenario and race conditions
// around targets in general (e.g., when symbolic links or duplicate files are involved)
return TargetDescriptions.GetOrAdd(result.ModuleName,
mn => CreateDescription(mn, source, reportedFileName, deps, buildMessages));
}
private async Task<PreflightResult> _performPreflight(RefSpec refSpec, CancellationToken token)
// requires refSpec.Source != null
// ensures result != null
{
if (refSpec.ErrorMessage != null)
return new PreflightResult { ErrorMessage = refSpec.ErrorMessage };
token.ThrowIfCancellationRequested();
_trace.TraceEvent(TraceEventType.Information, 0, "Preflight parsing of {0} requested.", refSpec);
// Make sure refSpec has a re-usable source (will have to support both preflight and actual compilation)
var source = refSpec.Source;
if (source == null)
throw new ArgumentException(Resources.SelfAssemblingPlan_RefSpecMustHaveSource, "refSpec");
var reportedPath = _getPath(source);
if (source.IsSingleUse)
source = await source.CacheInMemoryAsync();
token.ThrowIfCancellationRequested();
// Perform preflight parse
var eng = new Engine { ExecutionProhibited = true };
var app = new Application();
var ldr =
new Loader(new LoaderOptions(eng, app)
{
// Important: Have preflight flag set
PreflightModeEnabled = true,
ReconstructSymbols = false,
RegisterCommands = false,
StoreSourceInformation = false,
});
TextReader sourceReader;
if (!source.TryOpen(out sourceReader))
{
var errorResult = new PreflightResult
{
ErrorMessage =
"Failed to open " + refSpec + " for preflight parsing."
};
return errorResult;
}
ldr.LoadFromReader(sourceReader, refSpec.ResolvedPath != null ? refSpec.ResolvedPath.ToString() : null);
// Extract preflight information
ModuleName theModuleName;
if (!ModuleName.TryParse(app.Meta[Module.NameKey], out theModuleName))
theModuleName = app.Module.Name;
MetaEntry noStdLibEntry;
var result = new PreflightResult
{
ModuleName = theModuleName,
SuppressStandardLibrary =
app.Meta.TryGetValue(Module.NoStandardLibraryKey, out noStdLibEntry) && noStdLibEntry.Switch,
Path = reportedPath
};
result.References.AddRange(
app.Meta[Module.ReferencesKey].List.Where(entry => !entry.Equals(new MetaEntry("")))
.Select(_parseRefSpec));
_trace.TraceEvent(TraceEventType.Verbose, 0, "Preflight parsing of {0} finished.", refSpec);
return result;
}