/// <summary>
/// Creates a new document with preprocessor directives of the specified kind removed.
/// </summary>
/// <param name="document"></param>
/// <param name="directiveFilter"></param>
/// <param name="cancellationToken"></param>
public static async Task <Document> RemovePreprocessorDirectivesAsync(
this Document document,
PreprocessorDirectiveFilter directiveFilter,
CancellationToken cancellationToken = default)
{
if (document == null)
{
throw new ArgumentNullException(nameof(document));
}
SyntaxNode root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
SourceText sourceText = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
SourceText newSourceText = RemovePreprocessorDirectives(sourceText, root.DescendantPreprocessorDirectives(), directiveFilter);
return(document.WithText(newSourceText));
}
private static SourceText RemovePreprocessorDirectives(
SourceText sourceText,
IEnumerable <DirectiveTriviaSyntax> directives,
PreprocessorDirectiveFilter directiveFilter)
{
return(sourceText.WithChanges(GetTextChanges()));
IEnumerable <TextChange> GetTextChanges()
{
TextLineCollection lines = sourceText.Lines;
foreach (DirectiveTriviaSyntax directive in directives)
{
if (ShouldRemoveDirective(directive))
{
int startLine = directive.GetSpanStartLine();
yield return(new TextChange(lines[startLine].SpanIncludingLineBreak, ""));
}
}
}
bool ShouldRemoveDirective(DirectiveTriviaSyntax directive)
{
switch (directive.Kind())
{
case SyntaxKind.IfDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.If) != 0);
case SyntaxKind.ElifDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Elif) != 0);
case SyntaxKind.ElseDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Else) != 0);
case SyntaxKind.EndIfDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.EndIf) != 0);
case SyntaxKind.RegionDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Region) != 0);
case SyntaxKind.EndRegionDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.EndRegion) != 0);
case SyntaxKind.DefineDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Define) != 0);
case SyntaxKind.UndefDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Undef) != 0);
case SyntaxKind.ErrorDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Error) != 0);
case SyntaxKind.WarningDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Warning) != 0);
case SyntaxKind.LineDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Line) != 0);
case SyntaxKind.PragmaWarningDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.PragmaWarning) != 0);
case SyntaxKind.PragmaChecksumDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.PragmaChecksum) != 0);
case SyntaxKind.ReferenceDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Reference) != 0);
case SyntaxKind.BadDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Bad) != 0);
case SyntaxKind.ShebangDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Shebang) != 0);
case SyntaxKind.LoadDirectiveTrivia:
return((directiveFilter & PreprocessorDirectiveFilter.Load) != 0);
}
Debug.Fail(directive.Kind().ToString());
return(false);
}
}
