public void TestIsInstance()
{
Assert.False(SingleVariableDesignationSyntaxWrapper.IsInstance(null));
Assert.False(SingleVariableDesignationSyntaxWrapper.IsInstance(SyntaxFactory.LiteralExpression(SyntaxKind.NullLiteralExpression)));
var syntaxNode = SyntaxFactory.SingleVariableDesignation(SyntaxFactory.Identifier("Anything"));
Assert.True(SingleVariableDesignationSyntaxWrapper.IsInstance(syntaxNode));
}
private ProgramState VisitVariableDesignation(VariableDesignationSyntaxWrapper variableDesignation, ProgramState programState, bool singleVariable)
{
var newProgramState = programState;
if (DiscardDesignationSyntaxWrapper.IsInstance(variableDesignation))
{
// Push value for the discard, it will be popped when visiting the block for the
// corresponding case statement.
newProgramState = newProgramState.PushValue(SymbolicValue.Create());
}
else if (SingleVariableDesignationSyntaxWrapper.IsInstance(variableDesignation))
{
// "x is string s" is equivalent to "s = x"; both symbolic values should remain on stack
var singleVariableDesignation = (SingleVariableDesignationSyntaxWrapper)variableDesignation;
// associate variable with new SV
var variableSymbol = SemanticModel.GetDeclaredSymbol(singleVariableDesignation);
var newSymbolicValue = SymbolicValue.Create();
newProgramState = SetNewSymbolicValueIfTracked(variableSymbol, newSymbolicValue, newProgramState);
if (singleVariable)
{
// When the pattern is "x is Type t" we know that "t != null", hence (SV != null)
newProgramState = newProgramState.PushValue(new ValueNotEqualsSymbolicValue(newSymbolicValue, SymbolicValue.Null));
}
}
else if (ParenthesizedVariableDesignationSyntaxWrapper.IsInstance(variableDesignation))
{
var parenthesizedVariableDesignation = (ParenthesizedVariableDesignationSyntaxWrapper)variableDesignation;
foreach (var variable in parenthesizedVariableDesignation.Variables)
{
// the variables in the deconstruction should not receive "Not Null" constraint
newProgramState = VisitVariableDesignation(variable, newProgramState, singleVariable: false);
}
}
else
{
throw new NotSupportedException($"{variableDesignation.SyntaxNode.Kind()}");
}
return(newProgramState);
}
public void TestIsInstance()
{
Assert.False(SingleVariableDesignationSyntaxWrapper.IsInstance(null));
Assert.False(SingleVariableDesignationSyntaxWrapper.IsInstance(SyntaxFactory.LiteralExpression(SyntaxKind.NullLiteralExpression)));
}
