public bool RunOn(Program prog, PassInfo passInfo)
{
// We assume that types are uniqued so "GroupBy" works correctly
var groupedVariables = prog.TopLevelDeclarations.OfType <Constant>().Where(c => c.Unique).GroupBy(c => c.TypedIdent.Type);
bool changed = false;
foreach (var pair in groupedVariables)
{
var listOfUniqueVars = pair.ToList();
if (listOfUniqueVars.Count > 1)
{
Expr axiomExpr = null;
changed = true;
// Create IdentifierExprs
Dictionary <Variable, IdentifierExpr> ids = new Dictionary <Variable, IdentifierExpr>();
foreach (var uv in listOfUniqueVars)
{
ids.Add(uv, new IdentifierExpr(Token.NoToken, uv));
}
// Create an Expr asserting that all variables are different from each other (pair wise)
for (int firstVarIndex = 0; firstVarIndex < listOfUniqueVars.Count - 1; ++firstVarIndex)
{
for (int secondVarIndex = firstVarIndex + 1; secondVarIndex < listOfUniqueVars.Count; ++secondVarIndex)
{
var firstVar = listOfUniqueVars[firstVarIndex];
var secondVar = listOfUniqueVars[secondVarIndex];
var notEq = Expr.Neq(ids[firstVar], ids[secondVar]); // FIXME: Use ExprBuilder instead
if (axiomExpr == null)
{
axiomExpr = notEq;
}
else
{
axiomExpr = Expr.And(axiomExpr, notEq);
}
}
}
// Create the Axiom
var axiom = new Axiom(Token.NoToken, axiomExpr);
axiom.AddAttribute("symbooglix_enforce_unique", Expr.True);
prog.AddTopLevelDeclaration(axiom);
InternalAddedAxioms.Add(axiom);
Console.WriteLine("Adding axiom to enforce uniqueness of constant variables of {0} type that use the unique keyword", pair.Key.ToString());
}
}
return(changed);
}