public override Cmd VisitCallCmd(CallCmd node)
{
var result = base.VisitCallCmd(node);
var oldProc = programInCachedSnapshot.FindProcedure(node.Proc.Name);
if (oldProc != null
&& oldProc.DependencyChecksum != node.Proc.DependencyChecksum
&& node.AssignedAssumptionVariable == null)
{
var before = new List<Cmd>();
var beforePrecondtionCheck = new List<Cmd>();
var after = new List<Cmd>();
var axioms = new List<Axiom>();
Expr assumedExpr = new LiteralExpr(Token.NoToken, false);
// TODO(wuestholz): Try out two alternatives: only do this for low priority implementations or not at all.
var canUseSpecs = DependencyCollector.CanExpressOldSpecs(oldProc, Program);
if (canUseSpecs && oldProc.SignatureEquals(node.Proc))
{
var desugaring = node.Desugaring;
Contract.Assert(desugaring != null);
var precond = node.CheckedPrecondition(oldProc, Program, e => FunctionExtractor.Extract(e, Program, axioms));
if (precond != null)
{
var assume = new AssumeCmd(node.tok, precond, new QKeyValue(Token.NoToken, "precondition_previous_snapshot", new List<object>(), null));
assume.IrrelevantForChecksumComputation = true;
beforePrecondtionCheck.Add(assume);
}
var unmods = node.UnmodifiedBefore(oldProc);
var eqs = new List<Expr>();
foreach (var unmod in unmods)
{
var oldUnmod = new LocalVariable(Token.NoToken,
new TypedIdent(Token.NoToken, string.Format("{0}##old##{1}", unmod.Name, FreshTemporaryVariableName), unmod.Type));
var lhs = new SimpleAssignLhs(Token.NoToken, new IdentifierExpr(Token.NoToken, oldUnmod));
var rhs = new IdentifierExpr(Token.NoToken, unmod.Decl);
var cmd = new AssignCmd(Token.NoToken, new List<AssignLhs> { lhs }, new List<Expr> { rhs });
cmd.IrrelevantForChecksumComputation = true;
before.Add(cmd);
var eq = LiteralExpr.Eq(new IdentifierExpr(Token.NoToken, oldUnmod), new IdentifierExpr(Token.NoToken, unmod.Decl));
eq.Type = Type.Bool;
eq.TypeParameters = SimpleTypeParamInstantiation.EMPTY;
eqs.Add(eq);
}
var mods = node.ModifiedBefore(oldProc);
var oldSubst = new Dictionary<Variable, Expr>();
foreach (var mod in mods)
{
var oldMod = new LocalVariable(Token.NoToken,
new TypedIdent(Token.NoToken, string.Format("{0}##old##{1}", mod.Name, FreshTemporaryVariableName), mod.Type));
oldSubst[mod.Decl] = new IdentifierExpr(Token.NoToken, oldMod);
var lhs = new SimpleAssignLhs(Token.NoToken, new IdentifierExpr(Token.NoToken, oldMod));
var rhs = new IdentifierExpr(Token.NoToken, mod.Decl);
var cmd = new AssignCmd(Token.NoToken, new List<AssignLhs> { lhs }, new List<Expr> { rhs });
cmd.IrrelevantForChecksumComputation = true;
before.Add(cmd);
}
assumedExpr = node.Postcondition(oldProc, eqs, oldSubst, Program, e => FunctionExtractor.Extract(e, Program, axioms));
if (assumedExpr == null)
{
assumedExpr = new LiteralExpr(Token.NoToken, true);
}
}
if (assumedExpr != null)
{
var lv = new LocalVariable(Token.NoToken,
new TypedIdent(Token.NoToken, string.Format("a##cached##{0}", FreshAssumptionVariableName), Type.Bool),
new QKeyValue(Token.NoToken, "assumption", new List<object>(), null));
node.AssignedAssumptionVariable = lv;
currentImplementation.InjectAssumptionVariable(lv, !canUseSpecs);
var lhs = new SimpleAssignLhs(Token.NoToken, new IdentifierExpr(Token.NoToken, lv));
var rhs = LiteralExpr.And(new IdentifierExpr(Token.NoToken, lv), assumedExpr);
var assumed = new AssignCmd(node.tok, new List<AssignLhs> { lhs }, new List<Expr> { rhs });
assumed.IrrelevantForChecksumComputation = true;
after.Add(assumed);
}
node.ExtendDesugaring(before, beforePrecondtionCheck, after);
if (CommandLineOptions.Clo.TraceCachingForTesting || CommandLineOptions.Clo.TraceCachingForBenchmarking)
{
using (var tokTxtWr = new TokenTextWriter("<console>", Console.Out, false, false))
{
var loc = node.tok != null && node.tok != Token.NoToken ? string.Format("{0}({1},{2})", node.tok.filename, node.tok.line, node.tok.col) : "<unknown location>";
Console.Out.WriteLine("Processing call to procedure {0} in implementation {1} (at {2}):", node.Proc.Name, currentImplementation.Name, loc);
foreach (var a in axioms)
{
Console.Out.Write(" >>> added axiom: ");
a.Expr.Emit(tokTxtWr);
Console.Out.WriteLine();
}
foreach (var b in before)
{
Console.Out.Write(" >>> added before: ");
b.Emit(tokTxtWr, 0);
}
foreach (var b in beforePrecondtionCheck)
{
Console.Out.Write(" >>> added before precondition check: ");
b.Emit(tokTxtWr, 0);
}
foreach (var a in after)
{
Console.Out.Write(" >>> added after: ");
a.Emit(tokTxtWr, 0);
}
}
}
}
return result;
}
