private HashSet <DVariable> GetVars(Expression exp, HashSet <DVariable> declaredVars)
{
DVariableComparer comparer = new DVariableComparer();
HashSet <DVariable> vars = new HashSet <DVariable>(comparer);
if (exp is SeqSelectExpr)
{
var expr = exp as SeqSelectExpr;
vars.UnionWith(GetVars(expr.Seq, declaredVars));
vars.UnionWith(GetVars(expr.E0, declaredVars));
vars.UnionWith(GetVars(expr.E1, declaredVars));
}
else if (exp is NameSegment)
{
var expr = exp as NameSegment;
DVariable var = new DVariable(expr.Name, expr.Type);
if (!declaredVars.Contains(var))
{
vars.Add(var);
}
}
else if (exp is ApplySuffix)
{
var expr = exp as ApplySuffix;
foreach (var arg in expr.Args)
{
vars.UnionWith(GetVars(arg, declaredVars));
}
}
else if (exp is BinaryExpr)
{
var expr = exp as BinaryExpr;
vars.UnionWith(GetVars(expr.E0, declaredVars));
vars.UnionWith(GetVars(expr.E1, declaredVars));
}
else if (exp is UnaryOpExpr)
{
var expr = exp as UnaryOpExpr;
vars.UnionWith(GetVars(expr.E, declaredVars));
}
else if (exp is ParensExpression)
{
var expr = exp as ParensExpression;
vars.UnionWith(GetVars(expr.E, declaredVars));
}
else if (exp is ChainingExpression)
{
var expr = exp as ChainingExpression;
vars.UnionWith(GetVars(expr.E, declaredVars));
}
else if (exp is SeqDisplayExpr)
{
var expr = exp as SeqDisplayExpr;
foreach (var arg in expr.Elements)
{
vars.UnionWith(GetVars(arg, declaredVars));
}
}
else if (exp is ForallExpr)
{
var expr = exp as ForallExpr;
var newDecVars = new HashSet <DVariable>(declaredVars, comparer);
if (expr.BoundVars != null)
{
foreach (var bvar in expr.BoundVars)
{
DVariable dvar = new DVariable(bvar.DisplayName, bvar.Type);
newDecVars.Add(dvar);
}
}
vars.UnionWith(GetVars(expr.Term, newDecVars));
}
return(vars);
}
private HashSet <DVariable> GetVars(Statement stmt, HashSet <DVariable> declaredVars, bool containNonModified)
{
DVariableComparer comparer = new DVariableComparer();
HashSet <DVariable> usedVars = new HashSet <DVariable>(comparer);
if (stmt is UpdateStmt)
{
var ustmt = (UpdateStmt)stmt;
foreach (var ls in ustmt.Lhss)
{
usedVars.UnionWith(GetVars(ls, declaredVars));
}
if (containNonModified)
{
foreach (var rs in ustmt.Rhss)
{
var exp = rs as ExprRhs;
usedVars.UnionWith(GetVars(exp.Expr, declaredVars));
}
}
}
else if (stmt is AssertStmt && containNonModified)
{
var asrt = stmt as AssertStmt;
usedVars.UnionWith(GetVars(asrt.Expr, declaredVars));
usedVars.UnionWith(GetVars(asrt.Proof, declaredVars, containNonModified));
}
else if (stmt is WhileStmt)
{
var wstmt = stmt as WhileStmt;
usedVars.UnionWith(GetVars(wstmt.Body, declaredVars, containNonModified));
foreach (var exp in wstmt.Decreases.Expressions)
{
usedVars.UnionWith(GetVars(exp, declaredVars));
}
usedVars.UnionWith(GetVars(wstmt.Guard, declaredVars));
foreach (var exp in wstmt.Invariants)
{
usedVars.UnionWith(GetVars(exp.E, declaredVars));
}
}
else if (stmt is BlockStmt)
{
var stmts = stmt as BlockStmt;
foreach (var bodyStmt in stmts.Body)
{
usedVars.UnionWith(GetVars(bodyStmt, declaredVars, containNonModified));
}
}
else if (stmt is VarDeclStmt)
{
var decl = stmt as VarDeclStmt;
usedVars.UnionWith(GetVars(decl.Update, declaredVars, containNonModified));
if (decl.Locals != null)
{
foreach (var v in decl.Locals)
{
DVariable dvar = new DVariable(v.DisplayName, v.Type);
declaredVars.Add(dvar);
}
}
}
else if (stmt is IfStmt)
{
var ifstmt = stmt as IfStmt;
usedVars.UnionWith(GetVars(ifstmt.Guard, declaredVars));
usedVars.UnionWith(GetVars(ifstmt.Thn, declaredVars, containNonModified));
usedVars.UnionWith(GetVars(ifstmt.Els, declaredVars, containNonModified));
}
else if (stmt is PrintStmt)
{
var pstmt = stmt as PrintStmt;
foreach (var arg in pstmt.Args)
{
usedVars.UnionWith(GetVars(arg, declaredVars));
}
}
return(usedVars);
}