public override List <Cmd> CreateUpdatesToRefinementVars(bool isMarkedCall)
{
var cmds = new List <Cmd>();
var pcOkUpdateLHS = new List <IdentifierExpr> {
Expr.Ident(pc), Expr.Ident(ok)
};
if (isMarkedCall)
{
// assert !pc;
// pc, ok := true, true;
cmds.Add(CmdHelper.AssertCmd(tok, Expr.Not(Expr.Ident(pc)), $"Layer-{layerNum + 1} state modified before marked call"));
var pcOkUpdateRHS = new List <Expr> {
Expr.True, Expr.True
};
cmds.Add(CmdHelper.AssignCmd(pcOkUpdateLHS, pcOkUpdateRHS));
}
else
{
// pc, ok := g_old == g ==> pc, transitionRelation(i, g_old, o, g) || (o_old == o && ok);
var pcOkUpdateRHS = new List <Expr> {
Expr.Imp(OldEqualityExprForGlobals(), Expr.Ident(pc)),
Expr.Or(transitionRelation, Expr.And(OldEqualityExprForOutputs(), Expr.Ident(ok))),
};
cmds.Add(CmdHelper.AssignCmd(pcOkUpdateLHS, pcOkUpdateRHS));
}
CivlUtil.ResolveAndTypecheck(cmds);
return(cmds);
}
public static void AddCheckers(CivlTypeChecker ctc)
{
foreach (var action in ctc.AllAtomicActions.Where(a => a.HasPendingAsyncs))
{
var requires = action.gate.Select(g => new Requires(false, g.Expr)).ToList();
var cmds = new List <Cmd>
{
CmdHelper.CallCmd(
action.proc,
action.impl.InParams.Select(Expr.Ident).ToList <Expr>(),
action.impl.OutParams.Select(Expr.Ident).ToList())
};
var blocks = new List <Block>()
{
new Block(Token.NoToken, "init", cmds, CmdHelper.ReturnCmd)
};
var PAs = Expr.Ident(action.impl.OutParams.Last(p => p.TypedIdent.Type.Equals(ctc.pendingAsyncMultisetType)));
var paBound = VarHelper.BoundVariable("pa", ctc.pendingAsyncType);
var pa = Expr.Ident(paBound);
var nonnegativeExpr =
new ForallExpr(Token.NoToken, new List <Variable> {
paBound
},
Expr.Ge(Expr.Select(PAs, pa), Expr.Literal(0)));
var correctTypeExpr = new ForallExpr(Token.NoToken, new List <Variable> {
paBound
},
Expr.Imp(
Expr.Gt(Expr.Select(PAs, pa), Expr.Literal(0)),
Expr.Or(action.pendingAsyncs.Select(a => ExprHelper.FunctionCall(a.pendingAsyncCtor.membership, pa)))));
var ensures = new List <Ensures>
{
new Ensures(false, nonnegativeExpr)
{
ErrorData = $"Action {action.proc.Name} might create negative pending asyncs"
},
new Ensures(false, correctTypeExpr)
{
ErrorData = $"Action {action.proc.Name} might create undeclared pending asyncs"
},
};
CivlUtil.ResolveAndTypecheck(ensures);
var proc = new Procedure(Token.NoToken, $"PendingAsyncChecker_{action.proc.Name}", new List <TypeVariable>(),
action.impl.InParams, action.impl.OutParams,
requires, action.proc.Modifies, ensures);
var impl = new Implementation(Token.NoToken, proc.Name, proc.TypeParameters,
proc.InParams, proc.OutParams, new List <Variable>(), blocks)
{
Proc = proc
};
ctc.program.AddTopLevelDeclaration(proc);
ctc.program.AddTopLevelDeclaration(impl);
}
}
public static void AddCheckers(CivlTypeChecker civlTypeChecker)
{
foreach (var action in civlTypeChecker.AllAtomicActions.Where(a => a.HasPendingAsyncs))
{
var requires = action.gate.Select(g => new Requires(false, g.Expr)).ToList();
var PAs = Expr.Ident(action.impl.OutParams.Last(p => p.TypedIdent.Type.Equals(civlTypeChecker.pendingAsyncMultisetType)));
var paBound = civlTypeChecker.BoundVariable("pa", civlTypeChecker.pendingAsyncType);
var pa = Expr.Ident(paBound);
var nonnegativeExpr =
ExprHelper.ForallExpr(new List <Variable> {
paBound
},
Expr.Ge(Expr.Select(PAs, pa), Expr.Literal(0)));
var correctTypeExpr = ExprHelper.ForallExpr(new List <Variable> {
paBound
},
Expr.Imp(
Expr.Gt(Expr.Select(PAs, pa), Expr.Literal(0)),
Expr.Or(action.pendingAsyncs.Select(a => ExprHelper.FunctionCall(a.pendingAsyncCtor.membership, pa)))));
CivlUtil.ResolveAndTypecheck(nonnegativeExpr);
CivlUtil.ResolveAndTypecheck(correctTypeExpr);
var cmds = new List <Cmd>
{
CmdHelper.CallCmd(
action.proc,
action.impl.InParams.Select(Expr.Ident).ToList <Expr>(),
action.impl.OutParams.Select(Expr.Ident).ToList()),
CmdHelper.AssertCmd(
action.proc.tok,
nonnegativeExpr,
$"Action {action.proc.Name} might create negative pending asyncs"),
CmdHelper.AssertCmd(
action.proc.tok,
correctTypeExpr,
$"Action {action.proc.Name} might create undeclared pending asyncs")
};
var blocks = new List <Block>()
{
BlockHelper.Block("init", cmds)
};
var proc = DeclHelper.Procedure(civlTypeChecker.AddNamePrefix($"PendingAsyncChecker_{action.proc.Name}"),
action.impl.InParams, action.impl.OutParams,
requires, action.proc.Modifies, new List <Ensures>());
var impl = DeclHelper.Implementation(proc, proc.InParams, proc.OutParams, new List <Variable>(), blocks);
civlTypeChecker.program.AddTopLevelDeclaration(proc);
civlTypeChecker.program.AddTopLevelDeclaration(impl);
}
}
public override List <Cmd> CreateUnchangedAssertCmds()
{
AssertCmd globalsAssertCmd = CmdHelper.AssertCmd(
tok,
Expr.And(this.oldGlobalMap.Select(kvPair => Expr.Eq(Expr.Ident(kvPair.Key), Expr.Ident(kvPair.Value)))),
$"A yield-to-yield fragment illegally modifies layer-{layerNum + 1} globals");
CivlUtil.ResolveAndTypecheck(globalsAssertCmd);
// assert pc ==> o_old == o;
AssertCmd outputsAssertCmd = CmdHelper.AssertCmd(
tok,
Expr.Imp(Expr.Ident(pc), OldEqualityExprForOutputs()),
$"A yield-to-yield fragment illegally modifies layer-{layerNum + 1} outputs");
CivlUtil.ResolveAndTypecheck(outputsAssertCmd);
return(new List <Cmd> {
globalsAssertCmd, outputsAssertCmd
});
}
public override List <Cmd> CreateAssertCmds()
{
// assert pc || g_old == g || transitionRelation(i, g_old, o, g);
var skipOrTransitionRelationAssertCmd = CmdHelper.AssertCmd(
tok,
Expr.Or(Expr.Ident(pc), Expr.Or(OldEqualityExprForGlobals(), transitionRelation)),
$"A yield-to-yield fragment modifies layer-{layerNum + 1} state in a way that does not match the refined atomic action");
CivlUtil.ResolveAndTypecheck(skipOrTransitionRelationAssertCmd);
// assert pc ==> g_old == g && o_old == o;
AssertCmd skipAssertCmd = CmdHelper.AssertCmd(
tok,
Expr.Imp(Expr.Ident(pc), Expr.And(OldEqualityExprForGlobals(), OldEqualityExprForOutputs())),
$"A yield-to-yield fragment modifies layer-{layerNum + 1} state subsequent to a yield-to-yield fragment that already modified layer-{layerNum + 1} state");
CivlUtil.ResolveAndTypecheck(skipAssertCmd);
return(new List <Cmd> {
skipOrTransitionRelationAssertCmd, skipAssertCmd
});
}
private static void AddChecker(CivlTypeChecker civlTypeChecker, Action action, List<Declaration> decls)
{
var linearTypeChecker = civlTypeChecker.linearTypeChecker;
// Note: The implementation should be used as the variables in the
// gate are bound to implementation and not to the procedure.
Implementation impl = action.impl;
List<Variable> inputs = impl.InParams;
List<Variable> outputs = impl.OutParams;
List<Variable> locals = new List<Variable>(2);
var paLocal1 = civlTypeChecker.LocalVariable("pa1", civlTypeChecker.pendingAsyncType);
var paLocal2 = civlTypeChecker.LocalVariable("pa2", civlTypeChecker.pendingAsyncType);
var pa1 = Expr.Ident(paLocal1);
var pa2 = Expr.Ident(paLocal2);
if (civlTypeChecker.pendingAsyncType != null)
{
locals.Add(paLocal1);
locals.Add(paLocal2);
}
List<Requires> requires = action.gate.Select(a => new Requires(false, a.Expr)).ToList();
List<LinearityCheck> linearityChecks = new List<LinearityCheck>();
foreach (var domain in linearTypeChecker.linearDomains.Values)
{
// Linear in vars
var inVars = inputs.Union(action.modifiedGlobalVars)
.Where(x => linearTypeChecker.FindDomainName(x) == domain.domainName)
.Where(x => InKinds.Contains(linearTypeChecker.FindLinearKind(x)))
.Select(Expr.Ident)
.ToList();
// Linear out vars
var outVars = inputs.Union(outputs).Union(action.modifiedGlobalVars)
.Where(x => linearTypeChecker.FindDomainName(x) == domain.domainName)
.Where(x => OutKinds.Contains(linearTypeChecker.FindLinearKind(x)))
.Select(Expr.Ident)
.ToList();
// First kind
// Permissions in linear output variables are a subset of permissions in linear input variables.
if (outVars.Count > 0)
{
linearityChecks.Add(new LinearityCheck(
null,
OutPermsSubsetInPerms(domain, inVars, outVars),
$"Potential linearity violation in outputs for domain {domain.domainName}.",
"variables"));
}
if (action is AtomicAction atomicAction && atomicAction.HasPendingAsyncs)
{
var PAs = Expr.Ident(atomicAction.impl.OutParams.Last());
foreach (var pendingAsync in atomicAction.pendingAsyncs)
{
var pendingAsyncLinearParams = PendingAsyncLinearParams(linearTypeChecker, domain, pendingAsync, pa1);
if (pendingAsyncLinearParams.Count == 0) continue;
// Second kind
// Permissions in linear output variables + linear inputs of a single pending async
// are a subset of permissions in linear input variables.
var exactlyOnePA = Expr.And(
ExprHelper.FunctionCall(pendingAsync.pendingAsyncCtor.membership, pa1),
Expr.Eq(Expr.Select(PAs, pa1), Expr.Literal(1)));
var outSubsetInExpr = OutPermsSubsetInPerms(domain, inVars, pendingAsyncLinearParams.Union(outVars));
linearityChecks.Add(new LinearityCheck(
exactlyOnePA,
outSubsetInExpr,
$"Potential linearity violation in outputs and pending async of {pendingAsync.proc.Name} for domain {domain.domainName}.",
$"single_{pendingAsync.proc.Name}"));
// Third kind
// If there are two identical pending asyncs, then their input permissions mut be empty.
var twoIdenticalPAs = Expr.And(
ExprHelper.FunctionCall(pendingAsync.pendingAsyncCtor.membership, pa1),
Expr.Ge(Expr.Select(PAs, pa1), Expr.Literal(2)));
var emptyPerms = OutPermsSubsetInPerms(domain, Enumerable.Empty<Expr>(), pendingAsyncLinearParams);
linearityChecks.Add(new LinearityCheck(
twoIdenticalPAs,
emptyPerms,
$"Potential linearity violation in identical pending asyncs of {pendingAsync.proc.Name} for domain {domain.domainName}.",
$"identical_{pendingAsync.proc.Name}"));
}
var pendingAsyncs = atomicAction.pendingAsyncs.ToList();
for (int i = 0; i < pendingAsyncs.Count; i++)
{
var pendingAsync1 = pendingAsyncs[i];
for (int j = i; j < pendingAsyncs.Count; j++)
{
var pendingAsync2 = pendingAsyncs[j];
var pendingAsyncLinearParams1 = PendingAsyncLinearParams(linearTypeChecker, domain, pendingAsync1, pa1);
var pendingAsyncLinearParams2 = PendingAsyncLinearParams(linearTypeChecker, domain, pendingAsync2, pa2);
if (pendingAsyncLinearParams1.Count == 0 || pendingAsyncLinearParams2.Count == 0) continue;
// Fourth kind
// Input permissions of two non-identical pending asyncs (possibly of the same action)
// are a subset of permissions in linear input variables.
var membership = Expr.And(
Expr.Neq(pa1, pa2),
Expr.And(
ExprHelper.FunctionCall(pendingAsync1.pendingAsyncCtor.membership, pa1),
ExprHelper.FunctionCall(pendingAsync2.pendingAsyncCtor.membership, pa2)));
var existing = Expr.And(
Expr.Ge(Expr.Select(PAs, pa1), Expr.Literal(1)),
Expr.Ge(Expr.Select(PAs, pa2), Expr.Literal(1)));
var noDuplication = OutPermsSubsetInPerms(domain, inVars, pendingAsyncLinearParams1.Union(pendingAsyncLinearParams2));
linearityChecks.Add(new LinearityCheck(
Expr.And(membership, existing),
noDuplication,
$"Potential lnearity violation in pending asyncs of {pendingAsync1.proc.Name} and {pendingAsync2.proc.Name} for domain {domain.domainName}.",
$"distinct_{pendingAsync1.proc.Name}_{pendingAsync2.proc.Name}"));
}
}
}
}
if (linearityChecks.Count == 0) return;
// Create checker blocks
List<Block> checkerBlocks = new List<Block>(linearityChecks.Count);
foreach (var lc in linearityChecks)
{
List<Cmd> cmds = new List<Cmd>(2);
if (lc.assume != null)
{
cmds.Add(CmdHelper.AssumeCmd(lc.assume));
}
cmds.Add(new AssertCmd(action.proc.tok, lc.assert) { ErrorData = lc.message });
var block = new Block(Token.NoToken, lc.name, cmds, CmdHelper.ReturnCmd);
CivlUtil.ResolveAndTypecheck(block, ResolutionContext.State.Two);
checkerBlocks.Add(block);
}
// Create init blocks
List<Block> blocks = new List<Block>(linearityChecks.Count + 1);
blocks.Add(
new Block(
Token.NoToken,
"init",
new List<Cmd> { CmdHelper.CallCmd(action.proc, inputs, outputs) },
new GotoCmd(Token.NoToken, checkerBlocks)));
blocks.AddRange(checkerBlocks);
// Create the whole check procedure
string checkerName = civlTypeChecker.AddNamePrefix($"LinearityChecker_{action.proc.Name}");
Procedure linCheckerProc = new Procedure(Token.NoToken, checkerName, new List<TypeVariable>(),
inputs, outputs, requires, action.proc.Modifies, new List<Ensures>());
Implementation linCheckImpl = new Implementation(Token.NoToken, checkerName,
new List<TypeVariable>(), inputs, outputs, locals, blocks);
linCheckImpl.Proc = linCheckerProc;
decls.Add(linCheckImpl);
decls.Add(linCheckerProc);
}