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)
));
}
/// <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 the 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 : CSharpSyntaxNode
{
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()));
}
LanguageVersion requiredVersion = feature.RequiredVersion();
if (availableVersion >= requiredVersion)
{
return(node);
}
if (!forceWarning)
{
return(this.AddError(node, availableVersion.GetErrorCode(), feature.Localize(), (int)requiredVersion));
}
SyntaxDiagnosticInfo rawInfo = new SyntaxDiagnosticInfo(availableVersion.GetErrorCode(), feature.Localize(), (int)requiredVersion);
return(this.AddError(node, ErrorCode.WRN_ErrorOverride, rawInfo, rawInfo.Code));
}
/// <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 void CheckFeatureAvailability(this MessageID feature, LanguageVersion availableVersion, DiagnosticBag diagnostics, Location errorLocation)
{
LanguageVersion requiredVersion = feature.RequiredVersion();
if (requiredVersion > availableVersion)
{
diagnostics.Add(availableVersion.GetErrorCode(), errorLocation, feature.Localize(), 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 static void ParseAndResolveReferencePaths(string switchName, string switchValue, string baseDirectory, List<string> builder, MessageID origin, List<Diagnostic> diagnostics)
{
if (string.IsNullOrEmpty(switchValue))
{
Debug.Assert(!string.IsNullOrEmpty(switchName));
AddDiagnostic(diagnostics, ErrorCode.ERR_SwitchNeedsString, MessageID.IDS_PathList.Localize(), switchName);
return;
}
foreach (string path in ParseSeparatedPaths(switchValue))
{
string resolvedPath = FileUtilities.ResolveRelativePath(path, baseDirectory);
if (resolvedPath == null)
{
AddDiagnostic(diagnostics, ErrorCode.WRN_InvalidSearchPathDir, path, origin.Localize(), MessageID.IDS_DirectoryHasInvalidPath.Localize());
}
else if (!PortableShim.Directory.Exists(resolvedPath))
{
AddDiagnostic(diagnostics, ErrorCode.WRN_InvalidSearchPathDir, path, origin.Localize(), MessageID.IDS_DirectoryDoesNotExist.Localize());
}
else
{
builder.Add(resolvedPath);
}
}
}
/// <summary>
/// Add an ERR_UnexpectedVariance diagnostic to the diagnostic bag.
/// </summary>
/// <param name="diagnostics">Diagnostic bag.</param>
/// <param name="unsafeTypeParameter">Type parameter that is not variance safe.</param>
/// <param name="context">Context in which type is not variance safe (e.g. method).</param>
/// <param name="locationProvider">Callback to provide location.</param>
/// <param name="locationArg">Callback argument.</param>
/// <param name="expectedVariance">Desired variance of type.</param>
private static void AddVarianceError <T>(
this DiagnosticBag diagnostics,
TypeParameterSymbol unsafeTypeParameter,
Symbol context,
LocationProvider <T> locationProvider,
T locationArg,
MessageID expectedVariance)
where T : Symbol
{
MessageID actualVariance;
switch (unsafeTypeParameter.Variance)
{
case VarianceKind.In:
actualVariance = MessageID.IDS_Contravariant;
break;
case VarianceKind.Out:
actualVariance = MessageID.IDS_Covariant;
break;
default:
Debug.Assert(false, "Unexpected variance " + unsafeTypeParameter.Variance);
return;
}
// Get a location that roughly represents the unsafe type parameter use.
// (Typically, the locationProvider will return the location of the entire type
// reference rather than the specific type parameter, for instance, returning
// "C<T>[]" for "interface I<in T> { C<T>[] F(); }" rather than the type parameter
// in "C<T>[]", but that is better than returning the location of T within "I<in T>".
var location = locationProvider(locationArg) ?? unsafeTypeParameter.Locations[0];
// CONSIDER: instead of using the same error code for all variance errors, we could use different codes for "requires input-safe",
// "requires output-safe", and "requires input-safe and output-safe". This would make the error codes much easier to document and
// much more actionable.
// UNDONE: related location for use is much more useful
diagnostics.Add(ErrorCode.ERR_UnexpectedVariance, location, context, unsafeTypeParameter, actualVariance.Localize(), expectedVariance.Localize());
}
private void ReduceLet(LetClauseSyntax let, QueryTranslationState state, DiagnosticBag diagnostics)
{
// A query expression with a let clause
// from x in e
// let y = f
// ...
// is translated into
// from * in ( e ) . Select ( x => new { x , y = f } )
// ...
var x = state.rangeVariable;
// We use a slightly different translation strategy. We produce
// from * in ( e ) . Select ( x => new Pair<X,Y>(x, f) )
// Where X is the type of x, and Y is the type of the expression f.
// Subsequently, x (or members of x, if it is a transparent identifier)
// are accessed as TRID.Item1 (or members of that), and y is accessed
// as TRID.Item2, where TRID is the compiler-generated identifier used
// to represent the transparent identifier in the result.
LambdaBodyFactory bodyFactory = (LambdaSymbol lambdaSymbol, ref Binder lambdaBodyBinder, DiagnosticBag d) =>
{
var xExpression = new BoundParameter(let, lambdaSymbol.Parameters[0])
{
WasCompilerGenerated = true
};
var yExpression = lambdaBodyBinder.BindValue(let.Expression, d, BindValueKind.RValue);
SourceLocation errorLocation = new SourceLocation(let.SyntaxTree, new TextSpan(let.Identifier.SpanStart, let.Expression.Span.End - let.Identifier.SpanStart));
if (!yExpression.HasAnyErrors && !yExpression.HasExpressionType())
{
MessageID id = MessageID.IDS_NULL;
if (yExpression.Kind == BoundKind.UnboundLambda)
{
id = ((UnboundLambda)yExpression).MessageID;
}
else if (yExpression.Kind == BoundKind.MethodGroup)
{
id = MessageID.IDS_MethodGroup;
}
else
{
Debug.Assert(yExpression.IsLiteralNull(), "How did we successfully bind an expression without a type?");
}
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, id.Localize());
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray <Symbol> .Empty, ImmutableArray.Create <BoundNode>(yExpression), CreateErrorType());
}
else if (!yExpression.HasAnyErrors && yExpression.Type.SpecialType == SpecialType.System_Void)
{
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, yExpression.Type);
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray <Symbol> .Empty, ImmutableArray.Create <BoundNode>(yExpression), yExpression.Type);
}
var construction = MakePair(let, x.Name, xExpression, let.Identifier.ValueText, yExpression, state, d);
// The bound block represents a closure scope for transparent identifiers captured in the let clause.
// Such closures shall be associated with the lambda body expression.
return(lambdaBodyBinder.CreateBlockFromExpression(let.Expression, lambdaBodyBinder.Locals, null, construction, d));
};
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x), let.Expression, bodyFactory);
state.rangeVariable = state.TransparentRangeVariable(this);
state.AddTransparentIdentifier(x.Name);
var y = state.AddRangeVariable(this, let.Identifier, diagnostics);
state.allRangeVariables[y].Add(let.Identifier.ValueText);
var invocation = MakeQueryInvocation(let, state.fromExpression, "Select", lambda, diagnostics);
state.fromExpression = MakeQueryClause(let, invocation, y, invocation);
}
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());
}
private static void AddVarianceError <T>(
this BindingDiagnosticBag diagnostics,
TypeParameterSymbol unsafeTypeParameter,
Symbol context,
LocationProvider <T> locationProvider,
T locationArg,
MessageID expectedVariance)
where T : Symbol
{
MessageID actualVariance;
switch (unsafeTypeParameter.Variance)
{
case VarianceKind.In:
actualVariance = MessageID.IDS_Contravariant;
break;
case VarianceKind.Out:
actualVariance = MessageID.IDS_Covariant;
break;
default:
throw ExceptionUtilities.UnexpectedValue(unsafeTypeParameter.Variance);
}
// Get a location that roughly represents the unsafe type parameter use.
// (Typically, the locationProvider will return the location of the entire type
// reference rather than the specific type parameter, for instance, returning
// "C<T>[]" for "interface I<in T> { C<T>[] F(); }" rather than the type parameter
// in "C<T>[]", but that is better than returning the location of T within "I<in T>".
var location = locationProvider(locationArg) ?? unsafeTypeParameter.Locations[0];
// CONSIDER: instead of using the same error code for all variance errors, we could use different codes for "requires input-safe",
// "requires output-safe", and "requires input-safe and output-safe". This would make the error codes much easier to document and
// much more actionable.
// UNDONE: related location for use is much more useful
if (!(context is TypeSymbol) && context.IsStatic && !context.IsAbstract && !context.IsVirtual)
{
diagnostics.Add(ErrorCode.ERR_UnexpectedVarianceStaticMember, location, context, unsafeTypeParameter, actualVariance.Localize(), expectedVariance.Localize(),
new CSharpRequiredLanguageVersion(MessageID.IDS_FeatureVarianceSafetyForStaticInterfaceMembers.RequiredVersion()));
}
else
{
diagnostics.Add(ErrorCode.ERR_UnexpectedVariance, location, context, unsafeTypeParameter, actualVariance.Localize(), expectedVariance.Localize());
}
}
private void CheckFeatureAvailability(MessageID feature)
{
LanguageVersion availableVersion = this.Options.LanguageVersion;
var requiredVersion = feature.RequiredVersion();
if (availableVersion >= requiredVersion) return;
var featureName = feature.Localize();
this.AddError(availableVersion.GetErrorCode(), featureName, requiredVersion.Localize());
}