internal override BoundStatement BindSwitchStatementCore(SwitchStatementSyntax node, Binder originalBinder, BindingDiagnosticBag diagnostics)
{
Debug.Assert(SwitchSyntax.Equals(node));
if (node.Sections.Count == 0)
{
diagnostics.Add(ErrorCode.WRN_EmptySwitch, node.OpenBraceToken.GetLocation());
}
// Bind switch expression and set the switch governing type.
BoundExpression boundSwitchGoverningExpression = SwitchGoverningExpression;
diagnostics.AddRange(SwitchGoverningDiagnostics, allowMismatchInDependencyAccumulation: true);
ImmutableArray <BoundSwitchSection> switchSections = BindSwitchSections(originalBinder, diagnostics, out BoundSwitchLabel defaultLabel);
ImmutableArray <LocalSymbol> locals = GetDeclaredLocalsForScope(node);
ImmutableArray <LocalFunctionSymbol> functions = GetDeclaredLocalFunctionsForScope(node);
BoundDecisionDag decisionDag = DecisionDagBuilder.CreateDecisionDagForSwitchStatement(
compilation: this.Compilation,
syntax: node,
switchGoverningExpression: boundSwitchGoverningExpression,
switchSections: switchSections,
// If there is no explicit default label, the default action is to break out of the switch
defaultLabel: defaultLabel?.Label ?? BreakLabel,
diagnostics);
// Report subsumption errors, but ignore the input's constant value for that.
CheckSwitchErrors(node, boundSwitchGoverningExpression, ref switchSections, decisionDag, diagnostics);
// When the input is constant, we use that to reshape the decision dag that is returned
// so that flow analysis will see that some of the cases may be unreachable.
decisionDag = decisionDag.SimplifyDecisionDagIfConstantInput(boundSwitchGoverningExpression);
return(new BoundSwitchStatement(
syntax: node,
expression: boundSwitchGoverningExpression,
innerLocals: locals,
innerLocalFunctions: functions,
switchSections: switchSections,
defaultLabel: defaultLabel,
breakLabel: this.BreakLabel,
reachabilityDecisionDag: decisionDag));
}
public BoundDecisionDag GetDecisionDagForLowering(CSharpCompilation compilation)
{
BoundDecisionDag decisionDag = this.ReachabilityDecisionDag;
if (decisionDag.ContainsAnySynthesizedNodes())
{
decisionDag = DecisionDagBuilder.CreateDecisionDagForSwitchStatement(
compilation,
this.Syntax,
this.Expression,
this.SwitchSections,
this.DefaultLabel?.Label ?? this.BreakLabel,
BindingDiagnosticBag.Discarded,
forLowering: true);
Debug.Assert(!decisionDag.ContainsAnySynthesizedNodes());
}
return(decisionDag);
}