/// <summary>
/// An error/warning directive tells the compiler to indicate a syntactic error/warning
/// at the current location.
///
/// Format: #error Error message string
/// Resulting message: from the first non-whitespace character after the directive
/// keyword until the end of the directive (aka EOD) at the line break or EOF.
/// Resulting span: [first non-whitespace char, EOD)
///
/// Examples (pipes indicate span):
/// #error |goo|
/// #error |goo|
/// #error |goo |
/// #error |goo baz|
/// #error |//goo|
/// #error |/*goo*/|
/// #error |/*goo|
/// </summary>
/// <param name="hash">The '#' token.</param>
/// <param name="keyword">The 'error' or 'warning' token.</param>
/// <param name="isActive">True if the error/warning should be recorded.</param>
/// <returns>An ErrorDirective or WarningDirective node.</returns>
private DirectiveTriviaSyntax ParseErrorOrWarningDirective(SyntaxToken hash, SyntaxToken keyword, bool isActive)
{
var eod = this.ParseEndOfDirectiveWithOptionalPreprocessingMessage();
bool isError = keyword.Kind == SyntaxKind.ErrorKeyword;
if (isActive)
{
var triviaBuilder = new System.IO.StringWriter(System.Globalization.CultureInfo.InvariantCulture);
int triviaWidth = 0;
// whitespace and single line comments are trailing trivia on the keyword, the rest
// of the error message is leading trivia on the eod.
//
bool skipping = true;
foreach (var t in keyword.TrailingTrivia)
{
if (skipping)
{
if (t.Kind == SyntaxKind.WhitespaceTrivia)
{
continue;
}
skipping = false;
}
t.WriteTo(triviaBuilder, leading: true, trailing: true);
triviaWidth += t.FullWidth;
}
foreach (var node in eod.LeadingTrivia)
{
node.WriteTo(triviaBuilder, leading: true, trailing: true);
triviaWidth += node.FullWidth;
}
//relative to leading trivia of eod
//could be negative if part of the error text comes from the trailing trivia of the keyword token
int triviaOffset = eod.GetLeadingTriviaWidth() - triviaWidth;
string errorText = triviaBuilder.ToString();
eod = this.AddError(eod, triviaOffset, triviaWidth, isError ? ErrorCode.ERR_ErrorDirective : ErrorCode.WRN_WarningDirective, errorText);
if (isError)
{
if (errorText.Equals("version", StringComparison.Ordinal))
{
Assembly assembly = typeof(CSharpCompiler).GetTypeInfo().Assembly;
string version = CommonCompiler.GetAssemblyFileVersion(assembly);
eod = this.AddError(eod, triviaOffset, triviaWidth, ErrorCode.ERR_CompilerAndLanguageVersion, version,
this.Options.SpecifiedLanguageVersion.ToDisplayString());
}
else
{
const string versionMarker = "version:";
if (errorText.StartsWith(versionMarker, StringComparison.Ordinal) &&
LanguageVersionFacts.TryParse(errorText.Substring(versionMarker.Length), out var languageVersion))
{
ErrorCode error = this.Options.LanguageVersion.GetErrorCode();
eod = this.AddError(eod, triviaOffset, triviaWidth, error, "version", new CSharpRequiredLanguageVersion(languageVersion));
}
}
}
}
if (isError)
{
return(SyntaxFactory.ErrorDirectiveTrivia(hash, keyword, eod, isActive));
}
else
{
return(SyntaxFactory.WarningDirectiveTrivia(hash, keyword, eod, isActive));
}
}