private DirectiveTriviaSyntax?GetPreviousPossiblyRelatedDirective()
{
DirectiveTriviaSyntax?d = this;
while (d != null)
{
d = d.GetPreviousDirective();
if (d != null)
{
// skip matched sets
switch (d.Kind())
{
case SyntaxKind.EndIfDirectiveTrivia:
while (d != null && d.Kind() != SyntaxKind.IfDirectiveTrivia)
{
d = d.GetPreviousRelatedDirective();
}
continue;
case SyntaxKind.EndRegionDirectiveTrivia:
while (d != null && d.Kind() != SyntaxKind.RegionDirectiveTrivia)
{
d = d.GetPreviousRelatedDirective();
}
continue;
}
}
return(d);
}
return(null);
}
private DirectiveTriviaSyntax?GetPreviousRelatedDirective()
{
DirectiveTriviaSyntax?d = this;
switch (d.Kind())
{
case SyntaxKind.EndIfDirectiveTrivia:
while (d != null)
{
switch (d.Kind())
{
case SyntaxKind.IfDirectiveTrivia:
case SyntaxKind.ElifDirectiveTrivia:
case SyntaxKind.ElseDirectiveTrivia:
return(d);
}
d = d.GetPreviousPossiblyRelatedDirective();
}
break;
case SyntaxKind.ElifDirectiveTrivia:
d = d.GetPreviousPossiblyRelatedDirective();
while (d != null)
{
switch (d.Kind())
{
case SyntaxKind.IfDirectiveTrivia:
case SyntaxKind.ElifDirectiveTrivia:
return(d);
}
d = d.GetPreviousPossiblyRelatedDirective();
}
break;
case SyntaxKind.ElseDirectiveTrivia:
while (d != null)
{
switch (d.Kind())
{
case SyntaxKind.IfDirectiveTrivia:
case SyntaxKind.ElifDirectiveTrivia:
return(d);
}
d = d.GetPreviousPossiblyRelatedDirective();
}
break;
case SyntaxKind.EndRegionDirectiveTrivia:
while (d != null)
{
if (d.Kind() == SyntaxKind.RegionDirectiveTrivia)
{
return(d);
}
d = d.GetPreviousPossiblyRelatedDirective();
}
break;
}
return(null);
}
private ImmutableArray <Diagnostic> AnalyzeSemanticModel(SemanticModelAnalysisContext context, int positionOfFirstReducingNullableDirective, SimpleIntervalTree <TextSpan, TextSpanIntervalIntrospector>?codeBlockIntervalTree, SimpleIntervalTree <TextSpan, TextSpanIntervalIntrospector>?possibleNullableImpactIntervalTree)
{
var root = context.SemanticModel.SyntaxTree.GetCompilationUnitRoot(context.CancellationToken);
using (var simplifier = new NullableImpactingSpanWalker(context.SemanticModel, positionOfFirstReducingNullableDirective, ignoredSpans: codeBlockIntervalTree, context.CancellationToken))
{
simplifier.Visit(root);
possibleNullableImpactIntervalTree ??= new SimpleIntervalTree <TextSpan, TextSpanIntervalIntrospector>(new TextSpanIntervalIntrospector(), values: null);
foreach (var interval in simplifier.Spans)
{
possibleNullableImpactIntervalTree.AddIntervalInPlace(interval);
}
}
using var diagnostics = TemporaryArray <Diagnostic> .Empty;
var compilationOptions = ((CSharpCompilationOptions)context.SemanticModel.Compilation.Options).NullableContextOptions;
DirectiveTriviaSyntax? previousRetainedDirective = null;
NullableContextOptions?retainedOptions = compilationOptions;
DirectiveTriviaSyntax?currentOptionsDirective = null;
var currentOptions = retainedOptions;
for (var directive = root.GetFirstDirective(); directive is not null; directive = directive.GetNextDirective())
{
context.CancellationToken.ThrowIfCancellationRequested();
if (directive.IsKind(SyntaxKind.NullableDirectiveTrivia, out NullableDirectiveTriviaSyntax? nullableDirectiveTrivia))
{
// Once we reach a new directive, check to see if we can remove the previous directive
var removedCurrent = false;
if (IsReducing(retainedOptions, currentOptions))
{
// We can't have found a reducing directive and not know which directive it was
Contract.ThrowIfNull(currentOptionsDirective);
if (possibleNullableImpactIntervalTree is null ||
!possibleNullableImpactIntervalTree.HasIntervalThatOverlapsWith(currentOptionsDirective.Span.End, nullableDirectiveTrivia.SpanStart - currentOptionsDirective.Span.End))
{
diagnostics.Add(Diagnostic.Create(Descriptor, currentOptionsDirective.GetLocation()));
}
}
if (!removedCurrent)
{
previousRetainedDirective = currentOptionsDirective;
retainedOptions = currentOptions;
}
currentOptionsDirective = nullableDirectiveTrivia;
currentOptions = CSharpRemoveRedundantNullableDirectiveDiagnosticAnalyzer.GetNullableContextOptions(compilationOptions, currentOptions, nullableDirectiveTrivia);
}
else if (directive.IsKind(SyntaxKind.IfDirectiveTrivia, SyntaxKind.ElifDirectiveTrivia, SyntaxKind.ElseDirectiveTrivia))
{
possibleNullableImpactIntervalTree ??= new SimpleIntervalTree <TextSpan, TextSpanIntervalIntrospector>(new TextSpanIntervalIntrospector(), values: null);
possibleNullableImpactIntervalTree.AddIntervalInPlace(directive.Span);
}
}
// Once we reach the end of the file, check to see if we can remove the last directive
if (IsReducing(retainedOptions, currentOptions))
{
// We can't have found a reducing directive and not know which directive it was
Contract.ThrowIfNull(currentOptionsDirective);
if (possibleNullableImpactIntervalTree is null ||
!possibleNullableImpactIntervalTree.HasIntervalThatOverlapsWith(currentOptionsDirective.Span.End, root.Span.End - currentOptionsDirective.Span.End))
{
diagnostics.Add(Diagnostic.Create(Descriptor, currentOptionsDirective.GetLocation()));
}
}
return(diagnostics.ToImmutableAndClear());
}