private static CSDiagnosticInfo GetDisabledFeatureDiagnosticInfo(
MessageID feature,
LanguageVersion availableVersion
)
{
string?requiredFeature = feature.RequiredFeature();
if (requiredFeature != null)
{
return(new CSDiagnosticInfo(
ErrorCode.ERR_FeatureIsExperimental,
feature.Localize(),
requiredFeature
));
}
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)
));
}
internal bool IsFeatureEnabled(MessageID feature)
{
switch (feature)
{
case MessageID.IDS_FeatureBinaryLiteral:
case MessageID.IDS_FeatureDigitSeparator:
case MessageID.IDS_FeatureLocalFunctions:
case MessageID.IDS_FeatureRefLocalsReturns:
case MessageID.IDS_FeaturePatternMatching:
case MessageID.IDS_FeatureTuples:
case MessageID.IDS_FeatureReplace:
// in "demo" mode enable proposed new C# 7 language features.
if (PreprocessorSymbols.Contains("__DEMO__"))
{
return(true);
}
break;
default:
break;
}
string featureFlag = feature.RequiredFeature();
if (featureFlag != null)
{
return(Features.ContainsKey(featureFlag));
}
LanguageVersion availableVersion = LanguageVersion;
LanguageVersion requiredVersion = feature.RequiredVersion();
return(availableVersion >= requiredVersion);
}
internal bool IsFeatureEnabled(MessageID feature)
{
string?featureFlag = feature.RequiredFeature();
if (featureFlag != null)
{
return(Features.ContainsKey(featureFlag));
}
LanguageVersion availableVersion = LanguageVersion;
LanguageVersion requiredVersion = feature.RequiredVersion();
return(availableVersion >= requiredVersion);
}
/// <remarks>
/// NOTE: we are specifically diverging from dev11 to improve the user experience.
/// Since treating the "async" keyword as an identifier in older language
/// versions can never result in a correct program, we instead accept it as a
/// keyword regardless of the language version and produce an error if the version
/// is insufficient.
/// </remarks>
protected TNode CheckFeatureAvailability <TNode>(TNode node, MessageID feature, bool forceWarning = false)
where TNode : GreenNode
{
LanguageVersion availableVersion = this.Options.LanguageVersion;
if (feature == MessageID.IDS_FeatureModuleAttrLoc)
{
// There's a special error code for this feature, so handle it separately.
return(availableVersion >= LanguageVersion.CSharp2
? node
: this.AddError(node, ErrorCode.WRN_NonECMAFeature, feature.Localize()));
}
if (IsFeatureEnabled(feature))
{
return(node);
}
var featureName = feature.Localize();
var requiredFeature = feature.RequiredFeature();
if (requiredFeature != null)
{
if (forceWarning)
{
SyntaxDiagnosticInfo rawInfo = new SyntaxDiagnosticInfo(ErrorCode.ERR_FeatureIsExperimental, featureName, requiredFeature);
return(this.AddError(node, ErrorCode.WRN_ErrorOverride, rawInfo, rawInfo.Code));
}
return(this.AddError(node, ErrorCode.ERR_FeatureIsExperimental, featureName, requiredFeature));
}
else
{
var requiredVersion = feature.RequiredVersion();
if (forceWarning)
{
SyntaxDiagnosticInfo rawInfo = new SyntaxDiagnosticInfo(availableVersion.GetErrorCode(), featureName,
new CSharpRequiredLanguageVersion(requiredVersion));
return(this.AddError(node, ErrorCode.WRN_ErrorOverride, rawInfo, rawInfo.Code));
}
return(this.AddError(node, availableVersion.GetErrorCode(), featureName, new CSharpRequiredLanguageVersion(requiredVersion)));
}
}
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)));
}
private void CheckFeatureAvailability(MessageID feature)
{
var options = this.Options;
if (options.IsFeatureEnabled(feature))
{
return;
}
string requiredFeature = feature.RequiredFeature();
if (requiredFeature != null)
{
if (!options.IsFeatureEnabled(feature))
{
this.AddError(ErrorCode.ERR_FeatureIsExperimental, feature.Localize(), requiredFeature);
}
return;
}
LanguageVersion availableVersion = this.Options.LanguageVersion;
var requiredVersion = feature.RequiredVersion();
if (availableVersion >= requiredVersion) return;
var featureName = feature.Localize();
this.AddError(availableVersion.GetErrorCode(), featureName, requiredVersion.Localize());
}
