/// <summary>
/// Gets all the declared local variables in the given <paramref name="declarationStatement"/>.
/// </summary>
/// <param name="declarationStatement">Variable declaration statement</param>
public static ImmutableArray <ILocalSymbol> GetDeclaredVariables(this IVariableDeclarationsOperation declarationStatement)
{
if (declarationStatement == null)
{
throw new ArgumentNullException(nameof(declarationStatement));
}
var arrayBuilder = ArrayBuilder <ILocalSymbol> .GetInstance();
foreach (IVariableDeclarationOperation group in declarationStatement.Declarations)
{
foreach (ILocalSymbol symbol in group.Variables)
{
arrayBuilder.Add(symbol);
}
}
return(arrayBuilder.ToImmutableAndFree());
}
public sealed override void Initialize(AnalysisContext context)
{
context.RegisterOperationBlockStartAction(
(operationBlockContext) =>
{
if (operationBlockContext.OwningSymbol is IMethodSymbol containingMethod)
{
HashSet <ILocalSymbol> mightBecomeConstLocals = new HashSet <ILocalSymbol>();
HashSet <ILocalSymbol> assignedToLocals = new HashSet <ILocalSymbol>();
operationBlockContext.RegisterOperationAction(
(operationContext) =>
{
if (operationContext.Operation is IAssignmentOperation assignment)
{
AssignTo(assignment.Target, assignedToLocals, mightBecomeConstLocals);
}
else if (operationContext.Operation is IIncrementOrDecrementOperation increment)
{
AssignTo(increment.Target, assignedToLocals, mightBecomeConstLocals);
}
else
{
throw TestExceptionUtilities.UnexpectedValue(operationContext.Operation);
}
},
OperationKind.SimpleAssignment,
OperationKind.CompoundAssignment,
OperationKind.Increment);
operationBlockContext.RegisterOperationAction(
(operationContext) =>
{
IInvocationOperation invocation = (IInvocationOperation)operationContext.Operation;
foreach (IArgumentOperation argument in invocation.Arguments)
{
if (argument.Parameter.RefKind == RefKind.Out || argument.Parameter.RefKind == RefKind.Ref)
{
AssignTo(argument.Value, assignedToLocals, mightBecomeConstLocals);
}
}
},
OperationKind.Invocation);
operationBlockContext.RegisterOperationAction(
(operationContext) =>
{
IVariableDeclarationsOperation declaration = (IVariableDeclarationsOperation)operationContext.Operation;
foreach (IVariableDeclarationOperation variable in declaration.Declarations)
{
foreach (ILocalSymbol local in variable.Variables)
{
if (!local.IsConst && !assignedToLocals.Contains(local))
{
var localType = local.Type;
if ((!localType.IsReferenceType || localType.SpecialType == SpecialType.System_String) && localType.SpecialType != SpecialType.None)
{
if (variable.Initializer != null && variable.Initializer.Value.ConstantValue.HasValue)
{
mightBecomeConstLocals.Add(local);
}
}
}
}
}
},
OperationKind.VariableDeclarations);
operationBlockContext.RegisterOperationBlockEndAction(
(operationBlockEndContext) =>
{
foreach (ILocalSymbol couldBeConstLocal in mightBecomeConstLocals)
{
Report(operationBlockEndContext, couldBeConstLocal, LocalCouldBeConstDescriptor);
}
});
}
});
}
public override IOperation VisitVariableDeclarations(IVariableDeclarationsOperation operation, object argument)
{
return(new VariableDeclarationStatement(VisitArray(operation.Declarations), ((Operation)operation).SemanticModel, operation.Syntax, operation.Type, operation.ConstantValue, operation.IsImplicit));
}
public override void VisitVariableDeclarations(IVariableDeclarationsOperation operation)
{
base.VisitVariableDeclarations(operation);
}
public virtual void VisitVariableDeclarations(IVariableDeclarationsOperation operation)
{
DefaultVisit(operation);
}