public override CSharpSyntaxNode VisitToken(SyntaxToken token)
{
var leading = this.VisitList(token.LeadingTrivia);
var trailing = this.VisitList(token.TrailingTrivia);
if (leading != token.LeadingTrivia || trailing != token.TrailingTrivia)
{
if (leading != token.LeadingTrivia)
{
token = token.TokenWithLeadingTrivia(leading.Node);
}
if (trailing != token.TrailingTrivia)
{
token = token.TokenWithTrailingTrivia(trailing.Node);
}
}
return(token);
}
/// <summary>
/// Converts skippedSyntax node into tokens and adds these as trivia on the target token.
/// Also adds the first error (in depth-first preorder) found in the skipped syntax tree to the target token.
/// </summary>
internal SyntaxToken AddSkippedSyntax(SyntaxToken target, GreenNode skippedSyntax, bool trailing)
{
var builder = new SyntaxListBuilder(4);
// the error in we'll attach to the node
SyntaxDiagnosticInfo diagnostic = null;
// the position of the error within the skippedSyntax node full tree
int diagnosticOffset = 0;
int currentOffset = 0;
foreach (var node in skippedSyntax.EnumerateNodes())
{
SyntaxToken token = node as SyntaxToken;
if (token != null)
{
builder.Add(token.GetLeadingTrivia());
if (token.Width > 0)
{
// separate trivia from the tokens
SyntaxToken tk = token.TokenWithLeadingTrivia(null).TokenWithTrailingTrivia(null);
// adjust relative offsets of diagnostics attached to the token:
int leadingWidth = token.GetLeadingTriviaWidth();
if (leadingWidth > 0)
{
var tokenDiagnostics = tk.GetDiagnostics();
for (int i = 0; i < tokenDiagnostics.Length; i++)
{
var d = (SyntaxDiagnosticInfo)tokenDiagnostics[i];
tokenDiagnostics[i] = new SyntaxDiagnosticInfo(d.Offset - leadingWidth, d.Width, (ErrorCode)d.Code, d.Arguments);
}
}
builder.Add(SyntaxFactory.SkippedTokensTrivia(tk));
}
else
{
// do not create zero-width structured trivia, GetStructure doesn't work well for them
var existing = (SyntaxDiagnosticInfo)token.GetDiagnostics().FirstOrDefault();
if (existing != null)
{
diagnostic = existing;
diagnosticOffset = currentOffset;
}
}
builder.Add(token.GetTrailingTrivia());
currentOffset += token.FullWidth;
}
else if (node.ContainsDiagnostics && diagnostic == null)
{
// only propagate the first error to reduce noise:
var existing = (SyntaxDiagnosticInfo)node.GetDiagnostics().FirstOrDefault();
if (existing != null)
{
diagnostic = existing;
diagnosticOffset = currentOffset;
}
}
}
int triviaWidth = currentOffset;
var trivia = builder.ToListNode();
// total width of everything preceding the added trivia
int triviaOffset;
if (trailing)
{
var trailingTrivia = target.GetTrailingTrivia();
triviaOffset = target.FullWidth; //added trivia is full width (before addition)
target = target.TokenWithTrailingTrivia(SyntaxList.Concat(trailingTrivia, trivia));
}
else
{
// Since we're adding triviaWidth before the token, we have to add that much to
// the offset of each of its diagnostics.
if (triviaWidth > 0)
{
var targetDiagnostics = target.GetDiagnostics();
for (int i = 0; i < targetDiagnostics.Length; i++)
{
var d = (SyntaxDiagnosticInfo)targetDiagnostics[i];
targetDiagnostics[i] = new SyntaxDiagnosticInfo(d.Offset + triviaWidth, d.Width, (ErrorCode)d.Code, d.Arguments);
}
}
var leadingTrivia = target.GetLeadingTrivia();
target = target.TokenWithLeadingTrivia(SyntaxList.Concat(trivia, leadingTrivia));
triviaOffset = 0; //added trivia is first, so offset is zero
}
if (diagnostic != null)
{
int newOffset = triviaOffset + diagnosticOffset + diagnostic.Offset;
target = WithAdditionalDiagnostics(target,
new SyntaxDiagnosticInfo(newOffset, diagnostic.Width, (ErrorCode)diagnostic.Code, diagnostic.Arguments)
);
}
return(target);
}
