private AssignCmd VisitMapAssignment(AssignLhs lhs, Expr rhs)
{
Debug.Assert(lhs.DeepAssignedVariable.TypedIdent.Type.IsMap);
var ac = new AssignCmd(Token.NoToken, new List <AssignLhs>()
{
lhs
}, new List <Expr>()
{
rhs
});
if (lhs.Type.IsMap)
{
ac = VisitEntireMapAssignment(lhs, rhs);
return(ac);
}
var index = (lhs.AsExpr as NAryExpr).Args[1];
var l = VisitMapStore(lhs.DeepAssignedIdentifier, index, rhs);
if (l != null)
{
ac = new AssignCmd(Token.NoToken, new List <AssignLhs>(), new List <Expr>()); //overwrite
//to generate M'[x] := y
ac.Lhss = l
.Select(x => new MapAssignLhs(Token.NoToken, new SimpleAssignLhs(Token.NoToken, x.Item1), new List <Expr>()
{
index
}))
.ToList <AssignLhs>();
ac.Rhss = l
.Select(x => x.Item2)
.ToList();
}
return(ac);
}
/// <summary>
/// M := E
/// </summary>
/// <param name="lhs"></param>
/// <param name="rhs"></param>
/// <returns></returns>
private AssignCmd VisitEntireMapAssignment(AssignLhs lhs, Expr rhs)
{
Debug.Assert(lhs.DeepAssignedVariable.TypedIdent.Type.IsMap);
var ac = new AssignCmd(Token.NoToken, new List <AssignLhs>()
{
lhs
}, new List <Expr>()
{
rhs
});
//M := old(M)
if (!
(rhs is OldExpr &&
((OldExpr)rhs).Expr is IdentifierExpr &&
((IdentifierExpr)((OldExpr)rhs).Expr).Decl == lhs.DeepAssignedVariable)
)
{
Console.WriteLine("Don't handle direct stores M := e yet, found {0}", ac.ToString());
unhandledCommands.Add(ac);
return(ac);
}
var splitVars = allAllocSites
.Select(x => GetOrCreateSplitMap(lhs.DeepAssignedVariable, x))
.ToList();
ac.Lhss = splitVars.Select(x => (AssignLhs) new SimpleAssignLhs(Token.NoToken, IdentifierExpr.Ident(x))).ToList();
ac.Rhss = splitVars.Select(x => (Expr) new OldExpr(Token.NoToken, (Expr)IdentifierExpr.Ident(x))).ToList();
return(ac);
}
public static Expr SelectOfAssignLhs(AssignLhs lhs)
{
if (lhs is MapAssignLhs)
{
return(Expr.Select(SelectOfAssignLhs(((MapAssignLhs)lhs).Map), ((MapAssignLhs)lhs).Indexes));
}
else
{
return(Expr.Ident(lhs.DeepAssignedVariable));
}
}
public override Block VisitBlock(Block node)
{
foreach (Cmd c in node.Cmds)
{
AssignCmd ac = c as AssignCmd;
if (ac == null)
{
continue;
}
Utils.Assert(ac.Lhss.Count == 1 && ac.Rhss.Count == 1, "Expected assignments to have 1 lhs and 1 rhs");
AssignLhs lhs = ac.Lhss.ElementAt(0);
Expr rhs = ac.Rhss.ElementAt(0);
if (!(lhs.Type.IsBv && lhs.DeepAssignedIdentifier.Name.Equals("RSP")))
{
continue;
} //lhs is RSP
if (!(rhs is NAryExpr))
{
continue;
} //rhs is function application
if (!((NAryExpr)rhs).Fun.FunctionName.Equals("MINUS_64"))
{
continue;
} //rhs is a minus operation
if (!(((NAryExpr)rhs).Args.ElementAt(0) is IdentifierExpr))
{
continue;
} //1st argument is a id like RHS
if (!(((NAryExpr)rhs).Args.ElementAt(0) as IdentifierExpr).Name.Equals("RSP"))
{
continue;
} //1st argument is a id like RHS
if (!(((NAryExpr)rhs).Args.ElementAt(1) is LiteralExpr))
{
continue;
} //2nd argument is a constant like 384bv64
if (!((((NAryExpr)rhs).Args.ElementAt(1) as LiteralExpr).Type == BType.GetBvType(64)))
{
continue;
} //2nd argument is bitvector literal
int operand = ((((NAryExpr)rhs).Args.ElementAt(1) as LiteralExpr).asBvConst).Value.ToInt;
Utils.Assert(blocksWithinNautralLoops.All(x => x.Label != node.Label),
"Setting RSP within a loop: " + ac + " at label " + node.Label);
rsp_subtractions.Add(operand);
}
return(base.VisitBlock(node));
}
/* returns (mem, rcx, rdi, al) */
public static Tuple <Variable, Expr, Expr, Expr> getRepStosbArgs(AssignCmd c)
{
Utils.Assert(getSlashVerifyCmdType(c) == SlashVerifyCmdType.RepStosB, "getRepStosbArgs not a RepStosb command");
Utils.Assert(c.Lhss.Count == 1 && c.Rhss.Count == 1, "getRepStosbArgs not handling parallel assignCmds");
AssignLhs lhs = c.Lhss[0];
Expr rhs = c.Rhss[0];
Utils.Assert(((NAryExpr)rhs).Args.Count == 4, "RepStosb must have 4 arguments");
return(Tuple.Create <Variable, Expr, Expr, Expr>((((NAryExpr)rhs).Args[0] as IdentifierExpr).Decl,
((NAryExpr)rhs).Args[1],
((NAryExpr)rhs).Args[2],
((NAryExpr)rhs).Args[3]));
}
////////////////////////////////////////////////////////////////////////////////////
internal ReferenceExpression makeReferenceExpression(AssignLhs assignLhs)
{
if (assignLhs is SimpleAssignLhs)
{
return(makeReferenceExpression((SimpleAssignLhs)assignLhs));
}
else if (assignLhs is MapAssignLhs)
{
return(makeReferenceExpression((MapAssignLhs)assignLhs));
}
else
{
throw new Exception("Unsupported Boogie LHS type:" + assignLhs.ToString());
}
}
/////////////////////////////////////////////////////////////////////////////////////
private Expression getAssignmentSourceExpression(AssignLhs target, Expression source)
{
if (target is SimpleAssignLhs)
{
return(getAssignmentSourceExpression((SimpleAssignLhs)target, source));
}
else if (target is MapAssignLhs)
{
return(getAssignmentSourceExpression((MapAssignLhs)target, source));
}
else
{
throw new NotImplementedException();
}
}
public override Cmd VisitAssignCmd(AssignCmd node)
{
HashSet<Variable> rhsVars = new HashSet<Variable>();
for (int i = 0; i < node.Lhss.Count; i++)
{
AssignLhs lhs = node.Lhss[i];
Variable lhsVar = lhs.DeepAssignedVariable;
string domainName = FindDomainName(lhsVar);
if (domainName == null) continue;
if (!(lhs is SimpleAssignLhs))
{
Error(node, $"Only simple assignment allowed on linear variable {lhsVar.Name}");
continue;
}
IdentifierExpr rhs = node.Rhss[i] as IdentifierExpr;
if (rhs == null)
{
Error(node, $"Only variable can be assigned to linear variable {lhsVar.Name}");
continue;
}
string rhsDomainName = FindDomainName(rhs.Decl);
if (rhsDomainName == null)
{
Error(node, $"Only linear variable can be assigned to linear variable {lhsVar.Name}");
continue;
}
if (domainName != rhsDomainName)
{
Error(node,
$"Linear variable of domain {rhsDomainName} cannot be assigned to linear variable of domain {domainName}");
continue;
}
if (rhsVars.Contains(rhs.Decl))
{
Error(node, $"Linear variable {rhs.Decl.Name} can occur only once in the right-hand-side of an assignment");
continue;
}
rhsVars.Add(rhs.Decl);
}
return base.VisitAssignCmd(node);
}
// Return the variable that is being assigned to in the LHS of an assignment.
// id := ... then id
// m[...] := ... then m
private static IdentifierExpr getAssignedVariable(AssignLhs lhs)
{
if (lhs is SimpleAssignLhs)
{
SimpleAssignLhs sl = (SimpleAssignLhs)lhs;
return(sl.AssignedVariable);
}
else if (lhs is MapAssignLhs)
{
MapAssignLhs ml = (MapAssignLhs)lhs;
return(getAssignedVariable(ml.Map));
}
else
{
lhs.Emit(new TokenTextWriter(Console.Out));
throw new InternalError("Unknown type of AssignLhs");
}
}
/* returns (mem, addr, data) */
public static Tuple <Variable, Expr, Expr> getStoreArgs(AssignCmd c)
{
Func <Expr, string, bool> RhsMatch = delegate(Expr x, String s)
{
return(x is NAryExpr && ((NAryExpr)x).Fun.FunctionName.Equals(s));
};
Utils.Assert(c.Lhss.Count == 1 && c.Rhss.Count == 1, "getStoreArgs not handling parallel assignCmds");
AssignLhs lhs = c.Lhss[0];
Expr rhs = c.Rhss[0];
Utils.Assert(RhsMatch(rhs, "STORE_LE_8") || RhsMatch(rhs, "STORE_LE_16") || RhsMatch(rhs, "STORE_LE_32") || RhsMatch(rhs, "STORE_LE_64"),
"Expected store expression");
Utils.Assert(((NAryExpr)rhs).Args.Count == 3, "Store must have 3 arguments");
return(Tuple.Create <Variable, Expr, Expr>((((NAryExpr)rhs).Args[0] as IdentifierExpr).Decl,
((NAryExpr)rhs).Args[1],
((NAryExpr)rhs).Args[2]));
}
public static Duple <StoreLhs, Expr> Make(AssignLhs alhs, Expr e)
{
if (alhs is SimpleAssignLhs)
{
return(new Duple <StoreLhs, Expr>(new StoreLhs(alhs.DeepAssignedVariable), e));
}
if (alhs is MapAssignLhs)
{
var mlhs = alhs as MapAssignLhs;
var var = mlhs.DeepAssignedVariable;
var curLhs = mlhs.Map;
var curExpr = Expr.Store(SelectOfAssignLhs(curLhs), mlhs.Indexes, e);
if (curLhs is MapAssignLhs)
{
return(Make(curLhs, curExpr));
}
return(new Duple <StoreLhs, Expr>(new StoreLhs(var), curExpr));
}
return(null); //impossible!
}
/////////////////
// here begin the visit overrides that are only necessary for the cloning, and have nothing to do with the substitution itself
// --> one might move them to a clone visitor..
/////////////////
public override AssignLhs VisitMapAssignLhs(MapAssignLhs node)
{
var dispatchedIndices = new List <Expr>();
foreach (var ind in node.Indexes)
{
dispatchedIndices.Add(VisitExpr(ind));
}
AssignLhs newAssignLhs = null;
if (node.Map is MapAssignLhs)
{
newAssignLhs = VisitMapAssignLhs(node.Map as MapAssignLhs);
}
else if (node.Map is SimpleAssignLhs)
{
newAssignLhs = VisitSimpleAssignLhs(node.Map as SimpleAssignLhs);
}
return(new MapAssignLhs(node.tok, newAssignLhs, dispatchedIndices));
}
private AssignLhs TransformLhs(AssignLhs lhs)
{
var mapLhs = lhs as MapAssignLhs;
if (mapLhs == null ||
!(mapLhs.Map is SimpleAssignLhs) ||
mapLhs.Indexes.Count() != 1)
{
return((AssignLhs)Visit(lhs));
}
var map = (mapLhs.Map as SimpleAssignLhs).AssignedVariable;
if (!Arrays.ContainsKey(map.Name))
{
return((AssignLhs)Visit(lhs));
}
Debug.Assert(mapLhs.Indexes[0] is LiteralExpr);
return(new SimpleAssignLhs(
lhs.tok, new IdentifierExpr(Token.NoToken,
Eliminator.MakeVariableForArrayIndex(map.Decl, mapLhs.Indexes[0].ToString()))));
}
private Block Abstract(Block b)
{
var newCmds = new List <Cmd>();
foreach (Cmd c in b.Cmds)
{
if (c is CallCmd)
{
var call = c as CallCmd;
if (QKeyValue.FindBoolAttribute(call.Attributes, "atomic"))
{
// Discard the call
Debug.Assert(call.Ins.Count >= 1);
var ie = call.Ins[0] as IdentifierExpr;
Debug.Assert(ie != null);
Debug.Assert(verifier.ArrayModelledAdversarially(ie.Decl));
continue;
}
for (int i = 0; i < call.Ins.Count; i++)
{
ReadCollector rc = new ReadCollector(verifier.KernelArrayInfo);
rc.Visit(call.Ins[i]);
bool foundAdversarial = false;
foreach (AccessRecord ar in rc.NonPrivateAccesses)
{
if (verifier.ArrayModelledAdversarially(ar.V))
{
foundAdversarial = true;
break;
}
}
if (foundAdversarial)
{
LocalVariable lv = new LocalVariable(
Token.NoToken,
new TypedIdent(Token.NoToken, "_abstracted_call_arg_" + abstractedCallArgCounter, call.Ins[i].Type));
abstractedCallArgCounter++;
newLocalVars.Add(lv);
newCmds.Add(new HavocCmd(
Token.NoToken,
new List <IdentifierExpr>(new IdentifierExpr[] { new IdentifierExpr(Token.NoToken, lv) })));
call.Ins[i] = new IdentifierExpr(Token.NoToken, lv);
}
}
}
if (c is AssignCmd)
{
AssignCmd assign = c as AssignCmd;
var lhss = new List <AssignLhs>();
var rhss = new List <Expr>();
foreach (var lhsRhs in assign.Lhss.Zip(assign.Rhss))
{
AssignLhs lhs = lhsRhs.Item1;
Expr rhs = lhsRhs.Item2;
ReadCollector rc = new ReadCollector(verifier.KernelArrayInfo);
rc.Visit(rhs);
bool foundAdversarial = false;
foreach (AccessRecord ar in rc.NonPrivateAccesses)
{
if (verifier.ArrayModelledAdversarially(ar.V))
{
foundAdversarial = true;
break;
}
}
if (foundAdversarial)
{
Debug.Assert(lhs is SimpleAssignLhs);
newCmds.Add(new HavocCmd(c.tok, new List <IdentifierExpr>(new IdentifierExpr[] { (lhs as SimpleAssignLhs).AssignedVariable })));
continue;
}
WriteCollector wc = new WriteCollector(verifier.KernelArrayInfo);
wc.Visit(lhs);
if (wc.FoundNonPrivateWrite())
{
if (verifier.ArrayModelledAdversarially(wc.GetAccess().V))
{
continue; // Just remove the write
}
}
lhss.Add(lhs);
rhss.Add(rhs);
}
if (lhss.Count != 0)
{
newCmds.Add(new AssignCmd(assign.tok, lhss, rhss));
}
continue;
}
newCmds.Add(c);
}
b.Cmds = newCmds;
return(b);
}
/////////////////////////////////////////////////////////////////////////////////////
private ProgramVariable getAssignmentTarget(BasicBlock current, AssignLhs target)
{
return(scope.findVariable(scope.getVarUName(target.DeepAssignedVariable)));
}
private List <Cmd> AbstractAssign(AssignCmd acmd)
{
var newcmd = new List <Cmd>();
// !KeepSimple: then map indices are given special treatment
var KeepSimple = UseSimpleSlicing || (currImplementation == null) || (acmd.Lhss.Count != 1);
if (acmd.Lhss.Count != 1)
{
EncounteredParallelAssignment = true;
}
var newLhss = new List <AssignLhs>();
var newRhss = new List <Expr>();
var varsToHavoc = new HashSet <Variable>();
for (int i = 0; i < acmd.Lhss.Count; i++)
{
AssignLhs lhs = acmd.Lhss[i];
Expr rhs = acmd.Rhss[i];
//IdentifierExpr assignedVar = getAssignedVariable(lhs);
IdentifierExpr assignedVar = lhs.DeepAssignedIdentifier;
if (isTrackedVariable(assignedVar.Decl))
{
if (lhs is MapAssignLhs && !indicesAreTracked((MapAssignLhs)lhs))
{
// convert to assignedVar := *
varsToHavoc.Add(assignedVar.Decl);
}
else if (!isTracked(rhs))
{
// Convert to lhs := *
if (KeepSimple || lhs is SimpleAssignLhs)
{
varsToHavoc.Add(assignedVar.Decl);
}
else
{
// convert to "havoc lhs" as follows:
// havoc dummy; lhs := dummy;
// This is done when lhs is Mem[x]. We're not
// allowed to say "havoc Mem[x]".
// We should be doing this only when we can add new
// local variables
Debug.Assert(currImplementation != null);
// Get new local variable dummy
LocalVariable dummy = getNewLocal(lhs.Type, currImplementation);
// havoc dummy
newcmd.Add(BoogieAstFactory.MkHavocVar(dummy));
// lhs := dummy
newLhss.Add(lhs);
newRhss.Add(Expr.Ident(dummy));
}
}
else
{
// It is possible to come here because a variable may be untracked in this scope,
// yet tracked globally because it is on the lhs
newLhss.Add(lhs);
newRhss.Add(rhs);
}
}
}
if (newLhss.Count != 0)
{
newcmd.Add(new AssignCmd(Token.NoToken, newLhss, newRhss));
}
if (varsToHavoc.Count != 0)
{
var ieseq = new List <IdentifierExpr>();
varsToHavoc.Iter(v => ieseq.Add(Expr.Ident(v)));
newcmd.Add(new HavocCmd(Token.NoToken, ieseq));
}
return(newcmd);
}
/* looks at the function used in the NAryExpr to determine the type: LOAD8, LOAD16,...,STORE64 */
public static SlashVerifyCmdType getSlashVerifyCmdType(Cmd c)
{
Func <Expr, string, bool> RhsMatch = delegate(Expr x, String s)
{
return(x is NAryExpr && ((NAryExpr)x).Fun.FunctionName.Equals(s));
};
if (c is AssignCmd)
{
AssignCmd ac = c as AssignCmd;
Utils.Assert(ac.Lhss.Count == 1 && ac.Rhss.Count == 1, "getSlashVerifyCmdType not handling parallel assignCmds");
AssignLhs lhs = ac.Lhss[0];
Expr rhs = ac.Rhss[0];
if (lhs.Type.IsMap && RhsMatch(rhs, "STORE_LE_8"))
{
return(SlashVerifyCmdType.Store8);
}
else if (lhs.Type.IsMap && RhsMatch(rhs, "STORE_LE_16"))
{
return(SlashVerifyCmdType.Store16);
}
else if (lhs.Type.IsMap && RhsMatch(rhs, "STORE_LE_32"))
{
return(SlashVerifyCmdType.Store32);
}
else if (lhs.Type.IsMap && RhsMatch(rhs, "STORE_LE_64"))
{
return(SlashVerifyCmdType.Store64);
}
else if (lhs.Type.IsMap && RhsMatch(rhs, "REP_STOSB"))
{
return(SlashVerifyCmdType.RepStosB);
}
else if (lhs.Type.IsBv && lhs.DeepAssignedIdentifier.Name.Equals("RSP"))
{
return(SlashVerifyCmdType.SetRSP);
}
}
else if (c is AssertCmd)
{
AssertCmd ac = c as AssertCmd;
//extract instruction type
string attribute_cmdtype = QKeyValue.FindStringAttribute(ac.Attributes, "SlashVerifyCommandType");
string attribute_jmptarget = QKeyValue.FindStringAttribute(ac.Attributes, "SlashVerifyJmpTarget");
if (attribute_cmdtype != null &&
attribute_cmdtype.Equals("ret"))
{
return(SlashVerifyCmdType.Ret);
}
else if (attribute_cmdtype != null &&
attribute_cmdtype.Equals("call"))
{
return(SlashVerifyCmdType.Call);
}
else if (attribute_cmdtype != null && attribute_jmptarget != null &&
attribute_cmdtype.Equals("remotejmp"))
{
return(SlashVerifyCmdType.RemoteJmp);
}
else if (attribute_cmdtype != null && attribute_jmptarget != null &&
attribute_cmdtype.Equals("indirectjmp") && attribute_jmptarget.Equals("remote"))
{
return(SlashVerifyCmdType.RemoteIndirectJmp);
}
}
return(SlashVerifyCmdType.None);
}
