private BoundSwitchLabel BindSwitchSectionLabel(SwitchLabelSyntax node, Binder sectionBinder, DiagnosticBag diagnostics)
{
var switchGoverningType = GetSwitchGoverningType(diagnostics);
BoundExpression boundLabelExpressionOpt = null;
SourceLabelSymbol boundLabelSymbol = null;
ConstantValue labelExpressionConstant = null;
List<SourceLabelSymbol> matchedLabelSymbols;
// Prevent cascading diagnostics
bool hasErrors = node.HasErrors;
switch (node.Kind())
{
case SyntaxKind.CaseSwitchLabel:
var caseLabelSyntax = (CaseSwitchLabelSyntax)node;
// Bind the label case expression
boundLabelExpressionOpt = sectionBinder.BindValue(caseLabelSyntax.Value, diagnostics, BindValueKind.RValue);
boundLabelExpressionOpt = ConvertCaseExpression(switchGoverningType, caseLabelSyntax, boundLabelExpressionOpt, sectionBinder, ref labelExpressionConstant, diagnostics);
// Check for bind errors
hasErrors = hasErrors || boundLabelExpressionOpt.HasAnyErrors;
// SPEC: The constant expression of each case label must denote a value that
// SPEC: is implicitly convertible (§6.1) to the governing type of the switch statement.
// Prevent cascading diagnostics
if (!hasErrors && labelExpressionConstant == null)
{
diagnostics.Add(ErrorCode.ERR_ConstantExpected, caseLabelSyntax.Location);
hasErrors = true;
}
// LabelSymbols for all the switch case labels are created by BuildLabels().
// Fetch the matching switch case label symbols
matchedLabelSymbols = FindMatchingSwitchCaseLabels(labelExpressionConstant, caseLabelSyntax);
break;
case SyntaxKind.CasePatternSwitchLabel:
// pattern matching in case is not yet implemented.
if (!node.HasErrors)
{
Error(diagnostics, ErrorCode.ERR_FeatureIsUnimplemented, node, MessageID.IDS_FeaturePatternMatching.Localize());
hasErrors = true;
}
matchedLabelSymbols = new List<SourceLabelSymbol>();
break;
case SyntaxKind.DefaultSwitchLabel:
matchedLabelSymbols = GetDefaultLabels();
break;
default:
throw ExceptionUtilities.Unreachable;
}
// Get the corresponding matching label symbol created during BuildLabels()
// and also check for duplicate case labels.
Debug.Assert(hasErrors || !matchedLabelSymbols.IsEmpty());
bool first = true;
bool hasDuplicateErrors = false;
foreach (SourceLabelSymbol label in matchedLabelSymbols)
{
if (node.Equals(label.IdentifierNodeOrToken.AsNode()))
{
// we must have exactly one matching label created during BuildLabels()
boundLabelSymbol = label;
// SPEC: A compile-time error occurs if two or more case labels
// SPEC: in the same switch statement specify the same constant value.
if (!hasErrors && !first)
{
// Skipping the first label symbol ensures that the errors (if any),
// are reported on all but the first duplicate case label.
diagnostics.Add(ErrorCode.ERR_DuplicateCaseLabel, node.Location,
label.SwitchCaseLabelConstant?.Value ?? label.Name);
hasDuplicateErrors = true;
}
break;
}
first = false;
}
if ((object)boundLabelSymbol == null)
{
Debug.Assert(hasErrors);
boundLabelSymbol = new SourceLabelSymbol((MethodSymbol)this.ContainingMemberOrLambda, node, labelExpressionConstant);
}
return new BoundSwitchLabel(
syntax: node,
label: boundLabelSymbol,
expressionOpt: boundLabelExpressionOpt,
hasErrors: hasErrors || hasDuplicateErrors);
}
private BoundSwitchLabel BindSwitchSectionLabel(SwitchLabelSyntax node, DiagnosticBag diagnostics)
{
var switchGoverningType = GetSwitchGoverningType(diagnostics);
BoundExpression boundLabelExpressionOpt = null;
SourceLabelSymbol boundLabelSymbol = null;
ConstantValue labelExpressionConstant = null;
List<SourceLabelSymbol> matchedLabelSymbols;
// Prevent cascading diagnostics
bool hasErrors = node.HasErrors;
if (node.Value != null)
{
Debug.Assert(node.Kind == SyntaxKind.CaseSwitchLabel);
// Bind the label case expression
boundLabelExpressionOpt = BindValue(node.Value, diagnostics, BindValueKind.RValue);
boundLabelExpressionOpt = ConvertCaseExpression(switchGoverningType, node, boundLabelExpressionOpt, ref labelExpressionConstant, diagnostics);
// Check for bind errors
hasErrors = hasErrors || boundLabelExpressionOpt.HasAnyErrors;
// SPEC: The constant expression of each case label must denote a value that
// SPEC: is implicitly convertible (§6.1) to the governing type of the switch statement.
// Prevent cascading diagnostics
if (!hasErrors && labelExpressionConstant == null)
{
diagnostics.Add(ErrorCode.ERR_ConstantExpected, node.Location);
hasErrors = true;
}
// LabelSymbols for all the switch case labels are created by BuildLabels().
// Fetch the matching switch case label symbols
matchedLabelSymbols = FindMatchingSwitchCaseLabels(labelExpressionConstant, node);
}
else
{
Debug.Assert(node.Kind == SyntaxKind.DefaultSwitchLabel);
matchedLabelSymbols = GetDefaultLabels();
}
// Get the corresponding matching label symbol created during BuildLabels()
// and also check for duplicate case labels.
Debug.Assert(!matchedLabelSymbols.IsEmpty());
bool first = true;
bool hasDuplicateErrors = false;
foreach (SourceLabelSymbol label in matchedLabelSymbols)
{
if (node.Equals(label.IdentifierNodeOrToken.AsNode()))
{
// we must have exactly one matching label created during BuildLabels()
boundLabelSymbol = label;
// SPEC: A compile-time error occurs if two or more case labels
// SPEC: in the same switch statement specify the same constant value.
if (!hasErrors && !first)
{
// Skipping the first label symbol ensures that the errors (if any),
// are reported on all but the first duplicate case label.
diagnostics.Add(ErrorCode.ERR_DuplicateCaseLabel, node.Location,
label.SwitchCaseLabelConstant == null ? label.Name : label.SwitchCaseLabelConstant.Value);
hasDuplicateErrors = true;
}
break;
}
first = false;
}
if ((object)boundLabelSymbol == null)
{
Debug.Assert(hasErrors);
boundLabelSymbol = new SourceLabelSymbol(this.Owner, node, labelExpressionConstant);
}
return new BoundSwitchLabel(
syntax: node,
label: boundLabelSymbol,
expressionOpt: boundLabelExpressionOpt,
hasErrors: hasErrors || hasDuplicateErrors);
}