private bool _AreAllAccessesTheSame(IEnumerable <ArrayAccess> accesses)
{
// TODO maybe merge with the other iterations?
// Accessor does not have to be tracked as no more than one
// definition per instruction is possible.
Expression expectedExpression = null;
FlowNode expectedNode = null;
int expectedPosition = -1;
foreach (var access in accesses)
{
var accessor = _GetAccessor(access);
var expression = _GetAliasTarget(accessor.Variable, access.Node);
if (expectedExpression == null)
{
expectedExpression = expression;
expectedNode = access.Node;
expectedPosition = accessor.Position;
continue;
}
var equality = new ExpressionEquality(expectedNode, access.Node, _aliasAnalysis);
if (expectedPosition != accessor.Position || !equality.AreEqual(expectedExpression, expression))
{
return(false);
}
}
return(true);
}
private bool _IsSingleStepIncrement()
{
try {
// TODO maybe change this to use symbols, but this would require more checks.
var indexName = _loopIndex.Name;
var incrementor = _forStatement.Incrementors.Single();
var code = CodeFactory.Create(_forStatement.Incrementors.Single(), _semanticModel);
if (code.Root.Count != 1)
{
Debug.WriteLine($"the incrementor is not a single instruction: {incrementor}");
return(false);
}
var assignment = CodeFactory.Create(_forStatement.Incrementors.Single(), _semanticModel).Root.Single() as Assignment;
if (assignment == null)
{
Debug.WriteLine($"the incrementor is not an assignment as expected");
return(false);
}
if (!(assignment.Left is VariableExpression assigned) || !Equals(assigned?.Name, indexName))
{
Debug.WriteLine($"no incrementation of loop index");
return(false);
}
var equality = new ExpressionEquality();
return(equality.AreEqual(assignment.Right, new AddExpression(new VariableExpression(indexName), new IntegerExpression(1))));
} catch (UnsupportedSyntaxException e) {
Debug.WriteLine($"cannot check incrementor: {e.Message}");
return(false);
}
}
public void Initialize()
{
_instance = new ExpressionEquality();
}