internal static CSDiagnosticInfo?GetFeatureAvailabilityDiagnosticInfo(
this MessageID feature,
CSharpParseOptions options
) =>
options.IsFeatureEnabled(feature)
? null
: GetDisabledFeatureDiagnosticInfo(feature, options.LanguageVersion);
internal static CSDiagnosticInfo GetFeatureAvailabilityDiagnosticInfo(this MessageID feature, CSharpParseOptions options)
{
LanguageVersion requiredVersion;
if (options.IsFeatureEnabled(feature))
{
return(null);
}
string requiredFeature = feature.RequiredFeature();
if (requiredFeature != null)
{
return(new CSDiagnosticInfo(ErrorCode.ERR_FeatureIsExperimental, feature.Localize(), requiredFeature));
}
LanguageVersion availableVersion = options.LanguageVersion;
requiredVersion = feature.RequiredVersion();
return(requiredVersion == LanguageVersion.Preview.MapSpecifiedToEffectiveVersion()
? new CSDiagnosticInfo(ErrorCode.ERR_FeatureInPreview, feature.Localize())
: new CSDiagnosticInfo(availableVersion.GetErrorCode(), feature.Localize(), new CSharpRequiredLanguageVersion(requiredVersion)));
}