public static bool IsAccessOnNewlyCreatedObject(KnownSymbols knownSymbols,
SemanticModel semanticModel,
SyntaxNode node, RecursiveState recursiveState1)
{
bool IsOnNewlyCreatedObject(ExpressionSyntax exp)
{
if (exp is MemberAccessExpressionSyntax memberAccess1)
{
return(IsOnNewlyCreatedObject(memberAccess1.Expression));
}
if (exp is ElementAccessExpressionSyntax elementAccess1)
{
return(IsOnNewlyCreatedObject(elementAccess1.Expression));
}
return(Utils.IsNewlyCreatedObject(semanticModel, exp, knownSymbols, RecursiveIsNewlyCreatedObjectState.Empty(), recursiveState1));
}
if (node.Parent is MemberAccessExpressionSyntax memberAccess)
{
return(IsOnNewlyCreatedObject(memberAccess));
}
if (node is ElementAccessExpressionSyntax elementAccess)
{
return(IsOnNewlyCreatedObject(elementAccess));
}
return(false);
}
ChangeAcceptedPurityTypeBasedOnWhetherExpressionRepresentsANewObjectOrParameterBasedExpression(
PurityType currentAcceptedPurityType,
ExpressionSyntax node,
KnownSymbols knownSymbols,
SemanticModel semanticModel,
RecursiveState recursiveState)
{
if (Utils.IsNewlyCreatedObject(semanticModel, node, knownSymbols, RecursiveIsNewlyCreatedObjectState.Empty(), recursiveState))
{
return(PurityType.PureExceptLocally);
}
else if (ImpuritiesFinder.IsParameter(semanticModel, node))
{
return(PurityType.PureExceptReadLocally);
}
return(currentAcceptedPurityType);
}
public static IEnumerable <ExpressionSyntax> GetNonNewObjectReturnsForPropertyGet(
PropertyDeclarationSyntax propertyDeclaration,
SemanticModel semanticModel,
KnownSymbols knownSymbols,
RecursiveState recursiveState1)
{
var propertySymbol = semanticModel.GetDeclaredSymbol(propertyDeclaration);
if (propertySymbol.GetMethod == null)
{
yield break;
}
if (!propertySymbol.ReturnsByRef && IsCompleteValueType(propertySymbol.Type))
{
yield break;
}
List <ExpressionSyntax> returnExpressions;
if (propertyDeclaration.AccessorList != null)
{
var getAccessor =
propertyDeclaration.AccessorList.Accessors.FirstOrNoValue(x =>
x.Keyword.Kind() == SyntaxKind.GetKeyword);
if (getAccessor.HasNoValue)
{
yield break;
}
var getAccessorValue = getAccessor.GetValue();
returnExpressions =
getAccessorValue.ExpressionBody != null
? new List <ExpressionSyntax>()
{
getAccessorValue.ExpressionBody.Expression
}
: getAccessor.GetValue()
.DescendantNodes()
.OfType <ReturnStatementSyntax>()
.Select(x => x.Expression)
.ToList();
}
else if (propertyDeclaration.ExpressionBody != null)
{
returnExpressions = new List <ExpressionSyntax>()
{
propertyDeclaration.ExpressionBody.Expression
};
}
else
{
yield break;
}
foreach (var expression in returnExpressions)
{
if (!Utils.IsNewlyCreatedObject(semanticModel, expression, knownSymbols, RecursiveIsNewlyCreatedObjectState.Empty(), recursiveState1))
{
yield return(expression);
}
}
}
public static IEnumerable <ExpressionSyntax> GetNonNewObjectReturnsForMethod(
BaseMethodDeclarationSyntax methodDeclaration,
SemanticModel semanticModel,
KnownSymbols knownSymbols, RecursiveState recursiveState1)
{
var methodSymbol = semanticModel.GetDeclaredSymbol(methodDeclaration);
if (!methodSymbol.ReturnsByRef && IsCompleteValueType(methodSymbol.ReturnType))
{
yield break;
}
var returnExpressions =
methodDeclaration.Body != null
? methodDeclaration.Body
.DescendantNodes()
.OfType <ReturnStatementSyntax>()
.Select(x => x.Expression)
.ToArray()
: new[] { methodDeclaration.ExpressionBody.Expression };
foreach (var expression in returnExpressions)
{
if (!Utils.IsNewlyCreatedObject(semanticModel, expression, knownSymbols, RecursiveIsNewlyCreatedObjectState.Empty(), recursiveState1))
{
yield return(expression);
}
}
}
public static bool IsNewlyCreatedObject(SemanticModel semanticModel,
SyntaxNode expression,
KnownSymbols knownSymbols,
RecursiveIsNewlyCreatedObjectState recursiveState, RecursiveState recursiveState1)
{
if (expression is LiteralExpressionSyntax)
{
return(true);
}
if (expression is TupleExpressionSyntax tuple)
{
return(tuple.Arguments
.Select(x => x.Expression)
.All(x => IsNewlyCreatedObject(semanticModel, x, knownSymbols, recursiveState, recursiveState1)));
}
if (expression is ObjectCreationExpressionSyntax objectCreationExpression)
{
if (objectCreationExpression
.ArgumentList != null)
{
if (objectCreationExpression
.ArgumentList
.Arguments.Any(arg =>
!IsNewlyCreatedObject(semanticModel, arg.Expression, knownSymbols, recursiveState, recursiveState1)))
{
return(false);
}
}
if (objectCreationExpression.Initializer != null)
{
if (objectCreationExpression
.Initializer
.Expressions
.OfType <AssignmentExpressionSyntax>()
.Any(x =>
!IsNewlyCreatedObject(semanticModel, x.Right, knownSymbols, recursiveState, recursiveState1)))
{
return(false);
}
}
return(true);
}
if (expression is ArrayCreationExpressionSyntax arrayCreationExpression)
{
if (arrayCreationExpression.Initializer != null)
{
if (arrayCreationExpression
.Initializer
.Expressions
.Any(x =>
!IsNewlyCreatedObject(semanticModel, x, knownSymbols, recursiveState, recursiveState1)))
{
return(false);
}
}
return(true);
}
if (expression is ImplicitArrayCreationExpressionSyntax arrayCreationExpression1)
{
if (arrayCreationExpression1.Initializer != null)
{
if (arrayCreationExpression1
.Initializer
.Expressions
.Any(x =>
!IsNewlyCreatedObject(semanticModel, x, knownSymbols, recursiveState, recursiveState1)))
{
return(false);
}
}
return(true);
}
if (expression is InitializerExpressionSyntax initSyntax &&
initSyntax.Kind() == SyntaxKind.ArrayInitializerExpression)
{
if (initSyntax
.Expressions
.Any(x =>
!IsNewlyCreatedObject(semanticModel, x, knownSymbols, recursiveState, recursiveState1)))
{
return(false);
}
return(true);
}
if (expression is InvocationExpressionSyntax invocationExpression)
{
if (semanticModel.GetSymbolInfo(invocationExpression.Expression).Symbol is IMethodSymbol invokedMethod)
{
if (MethodReturnsNewObject(semanticModel, knownSymbols, recursiveState1, invokedMethod))
{
return(true);
}
}
}
if (expression is MemberAccessExpressionSyntax memberAccessExpression)
{
if (semanticModel.GetSymbolInfo(memberAccessExpression.Name).Symbol is IPropertySymbol propertySymbol && !GetUsage(memberAccessExpression.Name).IsWrite())
{
if (MethodReturnsNewObject(semanticModel, knownSymbols, recursiveState1, propertySymbol.GetMethod))
{
return(true);
}
}
}
if (expression is IdentifierNameSyntax identifier)
{
var identifierSymbol = semanticModel.GetSymbolInfo(identifier).Symbol;
if (identifierSymbol is ILocalSymbol local)
{
if (!local.IsRef && IsCompleteValueType(local.Type))
{
return(true);
}
if (recursiveState.VariablesUnderTest.Contains(local))
{
return(true);
}
var methodBody =
GetBodyOfMethodThatContainsExpression(expression);
if (methodBody.HasNoValue)
{
return(false);
}
var valuesInjectedIntoObject =
GetValuesPossiblyInjectedInto(semanticModel, local, methodBody.GetValue(), knownSymbols, recursiveState1);
if (!valuesInjectedIntoObject.All(x =>
{
var typeSymbol = semanticModel.GetTypeInfo(x).Type;
if (typeSymbol != null && IsImmutablePureData(typeSymbol))
{
return(true);
}
return(IsNewlyCreatedObject(semanticModel, x, knownSymbols, recursiveState.Add(local),
recursiveState1));
}))
{
return(false);
}
return(FindValuesAssignedToVariable(semanticModel, local, methodBody.GetValue()).All(x =>
IsNewlyCreatedObject(semanticModel, x, knownSymbols, recursiveState.Add(local), recursiveState1)));
}
}
if (semanticModel.GetTypeInfo(expression).Type is ITypeSymbol type)
{
if (IsCompleteValueType(type))
{
return(true);
}
}
return(false);
}
