public override Ensures VisitEnsures(Ensures ensures)
{
minLayerNum = int.MaxValue;
maxLayerNum = -1;
canAccessSharedVars = true;
Ensures ret = base.VisitEnsures(ensures);
canAccessSharedVars = false;
ActionInfo actionInfo = procToActionInfo[enclosingProc];
AtomicActionInfo atomicActionInfo = actionInfo as AtomicActionInfo;
if (atomicActionInfo != null && atomicActionInfo.ensures == ensures)
{
// This case has already been checked
}
else
{
CheckAndAddLayers(ensures, ensures.Attributes, actionInfo.createdAtLayerNum);
}
return(ret);
}
public void TypeCheck()
{
foreach (Declaration decl in program.TopLevelDeclarations)
{
Procedure proc = decl as Procedure;
if (proc == null)
{
continue;
}
foreach (Ensures e in proc.Ensures)
{
int phaseNum;
MoverType moverType = MoverCheck.GetMoverType(e, out phaseNum);
if (moverType == MoverType.Top)
{
continue;
}
CodeExpr codeExpr = e.Condition as CodeExpr;
if (codeExpr == null)
{
Error(e, "An atomic action must be a CodeExpr");
continue;
}
if (procToActionInfo.ContainsKey(proc))
{
Error(proc, "A procedure can have at most one atomic action");
continue;
}
procToActionInfo[proc] = new ActionInfo(proc, codeExpr, moverType, phaseNum);
}
}
this.VisitProgram(program);
#if QED
YieldTypeChecker.PerformYieldTypeChecking(this);
#endif
}
public override Ensures VisitEnsures(Ensures ensures)
{
ActionInfo actionInfo = procToActionInfo[enclosingProc];
AtomicActionInfo atomicActionInfo = actionInfo as AtomicActionInfo;
if (atomicActionInfo != null && atomicActionInfo.ensures == ensures)
{
// This case has already been checked
}
else
{
sharedVarsAccessed = new HashSet <Variable>();
Debug.Assert(introducedLocalVarsUpperBound == int.MinValue);
base.VisitEnsures(ensures);
CheckAndAddLayers(ensures, ensures.Attributes, actionInfo.createdAtLayerNum);
if (introducedLocalVarsUpperBound > Least(FindLayers(ensures.Attributes)))
{
Error(ensures, "An introduced local variable is accessed but not available");
}
introducedLocalVarsUpperBound = int.MinValue;
sharedVarsAccessed = null;
}
return(ensures);
}
public void TypeCheck()
{
foreach (var proc in program.Procedures)
{
if (!QKeyValue.FindBoolAttribute(proc.Attributes, "yields")) continue;
int createdAtLayerNum; // must be initialized by the following code, otherwise it is an error
int availableUptoLayerNum = int.MaxValue;
List<int> attrs = FindLayers(proc.Attributes);
if (attrs.Count == 1)
{
createdAtLayerNum = attrs[0];
}
else if (attrs.Count == 2)
{
createdAtLayerNum = attrs[0];
availableUptoLayerNum = attrs[1];
}
else
{
Error(proc, "Incorrect number of layers");
continue;
}
if (availableUptoLayerNum <= createdAtLayerNum)
{
Error(proc, "Creation layer number must be less than the available upto layer number");
continue;
}
foreach (Ensures e in proc.Ensures)
{
MoverType moverType = GetMoverType(e);
if (moverType == MoverType.Top) continue;
CodeExpr codeExpr = e.Condition as CodeExpr;
if (codeExpr == null)
{
Error(e, "An atomic action must be a CodeExpr");
continue;
}
if (procToActionInfo.ContainsKey(proc))
{
Error(proc, "A procedure can have at most one atomic action");
continue;
}
minLayerNum = int.MaxValue;
maxLayerNum = -1;
canAccessSharedVars = true;
enclosingProc = proc;
enclosingImpl = null;
base.VisitEnsures(e);
canAccessSharedVars = false;
if (maxLayerNum > createdAtLayerNum)
{
Error(e, "A variable being accessed is introduced after this action is created");
}
else if (availableUptoLayerNum > minLayerNum)
{
Error(e, "A variable being accessed is hidden before this action becomes unavailable");
}
else
{
procToActionInfo[proc] = new AtomicActionInfo(proc, e, moverType, createdAtLayerNum, availableUptoLayerNum);
}
}
if (errorCount > 0) continue;
if (!procToActionInfo.ContainsKey(proc))
{
procToActionInfo[proc] = new ActionInfo(proc, createdAtLayerNum, availableUptoLayerNum);
}
}
if (errorCount > 0) return;
foreach (var impl in program.Implementations)
{
if (!procToActionInfo.ContainsKey(impl.Proc)) continue;
procToActionInfo[impl.Proc].hasImplementation = true;
}
foreach (var proc in procToActionInfo.Keys)
{
ActionInfo actionInfo = procToActionInfo[proc];
if (actionInfo.isExtern && actionInfo.hasImplementation)
{
Error(proc, "Extern procedure cannot have an implementation");
continue;
}
if (actionInfo.isExtern || actionInfo.hasImplementation) continue;
if (leastUnimplementedLayerNum == int.MaxValue)
{
leastUnimplementedLayerNum = actionInfo.createdAtLayerNum;
}
else if (leastUnimplementedLayerNum != actionInfo.createdAtLayerNum)
{
Error(proc, "All unimplemented atomic actions must be created at the same layer");
}
}
foreach (var g in this.globalVarToSharedVarInfo.Keys)
{
var info = globalVarToSharedVarInfo[g];
if (!this.AllCreatedLayerNums.Contains(info.introLayerNum))
{
Error(g, "Variable must be introduced with creation of some atomic action");
}
if (info.hideLayerNum != int.MaxValue && !this.AllCreatedLayerNums.Contains(info.hideLayerNum))
{
Error(g, "Variable must be hidden with creation of some atomic action");
}
}
if (errorCount > 0) return;
this.VisitProgram(program);
foreach (Procedure proc in program.Procedures)
{
if (procToActionInfo.ContainsKey(proc)) continue;
foreach (var ie in proc.Modifies)
{
if (!SharedVariables.Contains(ie.Decl)) continue;
Error(proc, "A ghost procedure must not modify a global variable with layer annotation");
}
}
if (errorCount > 0) return;
YieldTypeChecker.PerformYieldSafeCheck(this);
new LayerEraser().VisitProgram(program);
}
private void CreateGatePreservationChecker(Program program, ActionInfo first, ActionInfo second)
{
Tuple <ActionInfo, ActionInfo> actionPair = new Tuple <ActionInfo, ActionInfo>(first, second);
if (gatePreservationCheckerCache.Contains(actionPair))
{
return;
}
gatePreservationCheckerCache.Add(actionPair);
List <Variable> inputs = new List <Variable>();
inputs.AddRange(first.thisInParams);
inputs.AddRange(second.thatInParams);
List <Variable> outputs = new List <Variable>();
outputs.AddRange(first.thisOutParams);
outputs.AddRange(second.thatOutParams);
List <Variable> locals = new List <Variable>();
locals.AddRange(second.thatAction.LocVars);
List <Block> secondBlocks = CloneBlocks(second.thatAction.Blocks);
List <Requires> requires = DisjointnessRequires(program, first, second);
List <Ensures> ensures = new List <Ensures>();
foreach (AssertCmd assertCmd in first.thisGate)
{
requires.Add(new Requires(false, assertCmd.Expr));
ensures.Add(new Ensures(false, assertCmd.Expr));
}
string checkerName = string.Format("GatePreservationChecker_{0}_{1}", first.proc.Name, second.proc.Name);
List <IdentifierExpr> globalVars = new List <IdentifierExpr>();
program.GlobalVariables().Iter(x => globalVars.Add(new IdentifierExpr(Token.NoToken, x)));
Procedure proc = new Procedure(Token.NoToken, checkerName, new List <TypeVariable>(), inputs, outputs, requires, globalVars, ensures);
Implementation impl = new Implementation(Token.NoToken, checkerName, new List <TypeVariable>(), inputs, outputs, locals, secondBlocks);
impl.Proc = proc;
this.decls.Add(impl);
this.decls.Add(proc);
}
private void CreateFailurePreservationChecker(Program program, ActionInfo first, ActionInfo second)
{
Tuple <ActionInfo, ActionInfo> actionPair = new Tuple <ActionInfo, ActionInfo>(first, second);
if (failurePreservationCheckerCache.Contains(actionPair))
{
return;
}
failurePreservationCheckerCache.Add(actionPair);
List <Variable> inputs = new List <Variable>();
inputs.AddRange(first.thisInParams);
inputs.AddRange(second.thatInParams);
Expr transitionRelation = (new TransitionRelationComputation(program, second)).Compute();
Expr expr = Expr.True;
foreach (AssertCmd assertCmd in first.thisGate)
{
expr = Expr.And(assertCmd.Expr, expr);
}
List <Requires> requires = DisjointnessRequires(program, first, second);
requires.Add(new Requires(false, Expr.Not(expr)));
foreach (AssertCmd assertCmd in second.thatGate)
{
requires.Add(new Requires(false, assertCmd.Expr));
}
Dictionary <Variable, Expr> map = new Dictionary <Variable, Expr>();
Dictionary <Variable, Expr> oldMap = new Dictionary <Variable, Expr>();
List <Variable> boundVars = new List <Variable>();
foreach (Variable v in program.GlobalVariables())
{
BoundVariable bv = new BoundVariable(Token.NoToken, new TypedIdent(Token.NoToken, "post_" + v.Name, v.TypedIdent.Type));
boundVars.Add(bv);
map[v] = new IdentifierExpr(Token.NoToken, bv);
}
foreach (Variable v in second.thatOutParams)
{
{
BoundVariable bv = new BoundVariable(Token.NoToken, new TypedIdent(Token.NoToken, "post_" + v.Name, v.TypedIdent.Type));
boundVars.Add(bv);
map[v] = new IdentifierExpr(Token.NoToken, bv);
}
{
BoundVariable bv = new BoundVariable(Token.NoToken, new TypedIdent(Token.NoToken, "pre_" + v.Name, v.TypedIdent.Type));
boundVars.Add(bv);
oldMap[v] = new IdentifierExpr(Token.NoToken, bv);
}
}
foreach (Variable v in second.thatAction.LocVars)
{
BoundVariable bv = new BoundVariable(Token.NoToken, new TypedIdent(Token.NoToken, "pre_" + v.Name, v.TypedIdent.Type));
boundVars.Add(bv);
oldMap[v] = new IdentifierExpr(Token.NoToken, bv);
}
Expr ensuresExpr = Expr.And(transitionRelation, Expr.Not(expr));
if (boundVars.Count > 0)
{
Substitution subst = Substituter.SubstitutionFromHashtable(map);
Substitution oldSubst = Substituter.SubstitutionFromHashtable(oldMap);
ensuresExpr = new ExistsExpr(Token.NoToken, boundVars, (Expr) new MySubstituter(subst, oldSubst).Visit(ensuresExpr));
}
List <Ensures> ensures = new List <Ensures>();
ensures.Add(new Ensures(false, ensuresExpr));
List <Block> blocks = new List <Block>();
blocks.Add(new Block(Token.NoToken, "L", new List <Cmd>(), new ReturnCmd(Token.NoToken)));
string checkerName = string.Format("FailurePreservationChecker_{0}_{1}", first.proc.Name, second.proc.Name);
List <IdentifierExpr> globalVars = new List <IdentifierExpr>();
program.GlobalVariables().Iter(x => globalVars.Add(new IdentifierExpr(Token.NoToken, x)));
Procedure proc = new Procedure(Token.NoToken, checkerName, new List <TypeVariable>(), inputs, new List <Variable>(), requires, globalVars, ensures);
Implementation impl = new Implementation(Token.NoToken, checkerName, new List <TypeVariable>(), inputs, new List <Variable>(), new List <Variable>(), blocks);
impl.Proc = proc;
this.decls.Add(impl);
this.decls.Add(proc);
}
public void TypeCheck()
{
foreach (var proc in program.Procedures)
{
if (!QKeyValue.FindBoolAttribute(proc.Attributes, "yields"))
{
continue;
}
int createdAtLayerNum; // must be initialized by the following code, otherwise it is an error
int availableUptoLayerNum = int.MaxValue;
List <int> attrs = FindLayers(proc.Attributes);
if (attrs.Count == 1)
{
createdAtLayerNum = attrs[0];
}
else if (attrs.Count == 2)
{
createdAtLayerNum = attrs[0];
availableUptoLayerNum = attrs[1];
}
else
{
Error(proc, "Incorrect number of layers");
continue;
}
foreach (Ensures e in proc.Ensures)
{
MoverType moverType = GetMoverType(e);
if (moverType == MoverType.Top)
{
continue;
}
CodeExpr codeExpr = e.Condition as CodeExpr;
if (codeExpr == null)
{
Error(e, "An atomic action must be a CodeExpr");
continue;
}
if (procToActionInfo.ContainsKey(proc))
{
Error(proc, "A procedure can have at most one atomic action");
continue;
}
if (availableUptoLayerNum <= createdAtLayerNum)
{
Error(proc, "Creation layer number must be less than the available upto layer number");
continue;
}
minLayerNum = int.MaxValue;
maxLayerNum = -1;
canAccessSharedVars = true;
enclosingProc = proc;
enclosingImpl = null;
base.VisitEnsures(e);
canAccessSharedVars = false;
if (maxLayerNum > createdAtLayerNum)
{
Error(e, "A variable being accessed is introduced after this action is created");
}
else if (availableUptoLayerNum > minLayerNum)
{
Error(e, "A variable being accessed is hidden before this action becomes unavailable");
}
else
{
procToActionInfo[proc] = new AtomicActionInfo(proc, e, moverType, createdAtLayerNum, availableUptoLayerNum);
}
}
if (errorCount > 0)
{
continue;
}
if (!procToActionInfo.ContainsKey(proc))
{
if (availableUptoLayerNum < createdAtLayerNum)
{
Error(proc, "Creation layer number must be no more than the available upto layer number");
continue;
}
else
{
procToActionInfo[proc] = new ActionInfo(proc, createdAtLayerNum, availableUptoLayerNum);
}
}
}
if (errorCount > 0)
{
return;
}
foreach (var impl in program.Implementations)
{
if (!procToActionInfo.ContainsKey(impl.Proc))
{
continue;
}
procToActionInfo[impl.Proc].hasImplementation = true;
}
foreach (var proc in procToActionInfo.Keys)
{
ActionInfo actionInfo = procToActionInfo[proc];
if (actionInfo.isExtern && actionInfo.hasImplementation)
{
Error(proc, "Extern procedure cannot have an implementation");
continue;
}
if (actionInfo.isExtern || actionInfo.hasImplementation)
{
continue;
}
if (leastUnimplementedLayerNum == int.MaxValue)
{
leastUnimplementedLayerNum = actionInfo.createdAtLayerNum;
}
else if (leastUnimplementedLayerNum != actionInfo.createdAtLayerNum)
{
Error(proc, "All unimplemented atomic actions must be created at the same layer");
}
}
foreach (var g in this.globalVarToSharedVarInfo.Keys)
{
var info = globalVarToSharedVarInfo[g];
if (!this.AllCreatedLayerNums.Contains(info.introLayerNum))
{
Error(g, "Variable must be introduced with creation of some atomic action");
}
if (info.hideLayerNum != int.MaxValue && !this.AllCreatedLayerNums.Contains(info.hideLayerNum))
{
Error(g, "Variable must be hidden with creation of some atomic action");
}
}
if (errorCount > 0)
{
return;
}
this.VisitProgram(program);
foreach (Procedure proc in program.Procedures)
{
if (procToActionInfo.ContainsKey(proc))
{
continue;
}
foreach (var ie in proc.Modifies)
{
if (!SharedVariables.Contains(ie.Decl))
{
continue;
}
Error(proc, "A ghost procedure must not modify a global variable with layer annotation");
}
}
if (errorCount > 0)
{
return;
}
YieldTypeChecker.PerformYieldSafeCheck(this);
new LayerEraser().VisitProgram(program);
}
private List <Requires> DisjointnessRequires(Program program, ActionInfo first, ActionInfo second)
{
List <Requires> requires = new List <Requires>();
Dictionary <string, HashSet <Variable> > domainNameToScope = new Dictionary <string, HashSet <Variable> >();
foreach (var domainName in linearTypeChecker.linearDomains.Keys)
{
domainNameToScope[domainName] = new HashSet <Variable>();
}
foreach (Variable v in program.GlobalVariables())
{
var domainName = linearTypeChecker.FindDomainName(v);
if (domainName == null)
{
continue;
}
domainNameToScope[domainName].Add(v);
}
foreach (Variable v in first.thisInParams)
{
var domainName = linearTypeChecker.FindDomainName(v);
if (domainName == null)
{
continue;
}
domainNameToScope[domainName].Add(v);
}
for (int i = 0; i < second.thatInParams.Count; i++)
{
var domainName = linearTypeChecker.FindDomainName(second.thisInParams[i]);
if (domainName == null)
{
continue;
}
domainNameToScope[domainName].Add(second.thatInParams[i]);
}
foreach (string domainName in domainNameToScope.Keys)
{
requires.Add(new Requires(false, linearTypeChecker.DisjointnessExpr(domainName, domainNameToScope[domainName])));
}
return(requires);
}
public void TypeCheck()
{
foreach (var proc in program.Procedures)
{
if (!QKeyValue.FindBoolAttribute(proc.Attributes, "pure"))
{
continue;
}
if (QKeyValue.FindBoolAttribute(proc.Attributes, "yields"))
{
Error(proc, "Pure procedure must not yield");
continue;
}
if (QKeyValue.FindBoolAttribute(proc.Attributes, "layer"))
{
Error(proc, "Pure procedure must not have layers");
continue;
}
if (proc.Modifies.Count > 0)
{
Error(proc, "Pure procedure must not modify a global variable");
continue;
}
procToAtomicProcedureInfo[proc] = new AtomicProcedureInfo();
}
foreach (var proc in program.Procedures)
{
if (QKeyValue.FindBoolAttribute(proc.Attributes, "yields"))
{
continue;
}
var procLayerNums = FindLayers(proc.Attributes);
if (procLayerNums.Count == 0)
{
continue;
}
foreach (IdentifierExpr ie in proc.Modifies)
{
if (!globalVarToSharedVarInfo.ContainsKey(ie.Decl))
{
Error(proc, "Atomic procedure cannot modify a global variable without layer numbers");
continue;
}
}
int lower, upper;
if (procLayerNums.Count == 1)
{
lower = procLayerNums[0];
upper = procLayerNums[0];
}
else if (procLayerNums.Count == 2)
{
lower = procLayerNums[0];
upper = procLayerNums[1];
if (lower >= upper)
{
Error(proc, "Lower layer must be less than upper layer");
continue;
}
}
else
{
Error(proc, "Atomic procedure must specify a layer range");
continue;
}
LayerRange layerRange = new LayerRange(lower, upper);
procToAtomicProcedureInfo[proc] = new AtomicProcedureInfo(layerRange);
}
if (errorCount > 0)
{
return;
}
foreach (Implementation impl in program.Implementations)
{
if (!procToAtomicProcedureInfo.ContainsKey(impl.Proc))
{
continue;
}
var atomicProcedureInfo = procToAtomicProcedureInfo[impl.Proc];
if (atomicProcedureInfo.isPure)
{
this.enclosingImpl = impl;
(new PurityChecker(this)).VisitImplementation(impl);
}
else
{
this.enclosingImpl = impl;
this.sharedVarsAccessed = new HashSet <Variable>();
(new PurityChecker(this)).VisitImplementation(impl);
LayerRange upperBound = FindLayerRange();
LayerRange lowerBound = atomicProcedureInfo.layerRange;
if (!lowerBound.Subset(upperBound))
{
Error(impl, "Atomic procedure cannot access global variable");
}
this.sharedVarsAccessed = null;
}
}
if (errorCount > 0)
{
return;
}
foreach (var proc in program.Procedures)
{
if (!QKeyValue.FindBoolAttribute(proc.Attributes, "yields"))
{
continue;
}
int createdAtLayerNum; // must be initialized by the following code, otherwise it is an error
int availableUptoLayerNum = int.MaxValue;
List <int> attrs = FindLayers(proc.Attributes);
if (attrs.Count == 1)
{
createdAtLayerNum = attrs[0];
}
else if (attrs.Count == 2)
{
createdAtLayerNum = attrs[0];
availableUptoLayerNum = attrs[1];
}
else
{
Error(proc, "Incorrect number of layers");
continue;
}
foreach (Ensures e in proc.Ensures)
{
MoverType moverType = GetMoverType(e);
if (moverType == MoverType.Top)
{
continue;
}
CodeExpr codeExpr = e.Condition as CodeExpr;
if (codeExpr == null)
{
Error(e, "An atomic action must be a CodeExpr");
continue;
}
if (procToActionInfo.ContainsKey(proc))
{
Error(proc, "A procedure can have at most one atomic action");
continue;
}
if (availableUptoLayerNum <= createdAtLayerNum)
{
Error(proc, "Creation layer number must be less than the available upto layer number");
continue;
}
sharedVarsAccessed = new HashSet <Variable>();
enclosingProc = proc;
enclosingImpl = null;
base.VisitEnsures(e);
LayerRange upperBound = FindLayerRange();
LayerRange lowerBound = new LayerRange(createdAtLayerNum, availableUptoLayerNum);
if (lowerBound.Subset(upperBound))
{
procToActionInfo[proc] = new AtomicActionInfo(proc, e, moverType, createdAtLayerNum, availableUptoLayerNum);
}
else
{
Error(e, "A variable being accessed in this action is unavailable");
}
sharedVarsAccessed = null;
}
if (errorCount > 0)
{
continue;
}
if (!procToActionInfo.ContainsKey(proc))
{
if (availableUptoLayerNum < createdAtLayerNum)
{
Error(proc, "Creation layer number must be no more than the available upto layer number");
continue;
}
else
{
procToActionInfo[proc] = new ActionInfo(proc, createdAtLayerNum, availableUptoLayerNum);
}
}
}
if (errorCount > 0)
{
return;
}
foreach (var impl in program.Implementations)
{
if (!procToActionInfo.ContainsKey(impl.Proc))
{
continue;
}
ActionInfo actionInfo = procToActionInfo[impl.Proc];
procToActionInfo[impl.Proc].hasImplementation = true;
if (actionInfo.isExtern)
{
Error(impl.Proc, "Extern procedure cannot have an implementation");
}
}
if (errorCount > 0)
{
return;
}
foreach (Procedure proc in procToActionInfo.Keys)
{
for (int i = 0; i < proc.InParams.Count; i++)
{
Variable v = proc.InParams[i];
var layer = FindLocalVariableLayer(proc, v, procToActionInfo[proc].createdAtLayerNum);
if (layer == int.MinValue)
{
continue;
}
localVarToLocalVariableInfo[v] = new LocalVariableInfo(layer);
}
for (int i = 0; i < proc.OutParams.Count; i++)
{
Variable v = proc.OutParams[i];
var layer = FindLocalVariableLayer(proc, v, procToActionInfo[proc].createdAtLayerNum);
if (layer == int.MinValue)
{
continue;
}
localVarToLocalVariableInfo[v] = new LocalVariableInfo(layer);
}
}
foreach (Implementation node in program.Implementations)
{
if (!procToActionInfo.ContainsKey(node.Proc))
{
continue;
}
foreach (Variable v in node.LocVars)
{
var layer = FindLocalVariableLayer(node, v, procToActionInfo[node.Proc].createdAtLayerNum);
if (layer == int.MinValue)
{
continue;
}
localVarToLocalVariableInfo[v] = new LocalVariableInfo(layer);
}
for (int i = 0; i < node.Proc.InParams.Count; i++)
{
Variable v = node.Proc.InParams[i];
if (!localVarToLocalVariableInfo.ContainsKey(v))
{
continue;
}
var layer = localVarToLocalVariableInfo[v].layer;
localVarToLocalVariableInfo[node.InParams[i]] = new LocalVariableInfo(layer);
}
for (int i = 0; i < node.Proc.OutParams.Count; i++)
{
Variable v = node.Proc.OutParams[i];
if (!localVarToLocalVariableInfo.ContainsKey(v))
{
continue;
}
var layer = localVarToLocalVariableInfo[v].layer;
localVarToLocalVariableInfo[node.OutParams[i]] = new LocalVariableInfo(layer);
}
}
if (errorCount > 0)
{
return;
}
this.VisitProgram(program);
if (errorCount > 0)
{
return;
}
YieldTypeChecker.PerformYieldSafeCheck(this);
new LayerEraser().VisitProgram(program);
}
public override Cmd VisitCallCmd(CallCmd node)
{
int enclosingProcLayerNum = procToActionInfo[enclosingImpl.Proc].createdAtLayerNum;
if (procToActionInfo.ContainsKey(node.Proc))
{
ActionInfo actionInfo = procToActionInfo[node.Proc];
if (node.IsAsync && actionInfo is AtomicActionInfo)
{
Error(node, "Target of async call cannot be an atomic action");
}
int calleeLayerNum = procToActionInfo[node.Proc].createdAtLayerNum;
if (enclosingProcLayerNum < calleeLayerNum ||
(enclosingProcLayerNum == calleeLayerNum && actionInfo is AtomicActionInfo))
{
Error(node, "The layer of the caller must be greater than the layer of the callee");
}
else if (enclosingProcLayerNum == calleeLayerNum && enclosingImpl.OutParams.Count > 0)
{
HashSet <Variable> outParams = new HashSet <Variable>(enclosingImpl.OutParams);
foreach (var x in node.Outs)
{
if (x.Decl is GlobalVariable)
{
Error(node, "A global variable cannot be used as output argument for this call");
}
else if (outParams.Contains(x.Decl))
{
Error(node, "An output variable of the enclosing implementation cannot be used as output argument for this call");
}
}
}
if (actionInfo.availableUptoLayerNum < enclosingProcLayerNum)
{
Error(node, "The callee is not available in the caller procedure");
}
for (int i = 0; i < node.Ins.Count; i++)
{
Visit(node.Ins[i]);
if (introducedLocalVarsUpperBound != int.MinValue)
{
var formal = node.Proc.InParams[i];
if (!localVarToLocalVariableInfo.ContainsKey(formal) ||
introducedLocalVarsUpperBound > localVarToLocalVariableInfo[formal].layer)
{
Error(node, "An introduced local variable is accessed but not available");
}
introducedLocalVarsUpperBound = int.MinValue;
}
}
for (int i = 0; i < node.Outs.Count; i++)
{
var formal = node.Proc.OutParams[i];
if (!localVarToLocalVariableInfo.ContainsKey(formal))
{
continue;
}
var actual = node.Outs[i].Decl;
if (localVarToLocalVariableInfo.ContainsKey(actual) &&
localVarToLocalVariableInfo[formal].layer <= localVarToLocalVariableInfo[actual].layer)
{
continue;
}
Error(node, "Formal parameter of call must be introduced no later than the actual parameter");
}
return(node);
}
else if (procToAtomicProcedureInfo.ContainsKey(node.Proc))
{
var atomicProcedureInfo = procToAtomicProcedureInfo[node.Proc];
if (atomicProcedureInfo.isPure)
{
if (node.Outs.Count > 0)
{
int inferredLayer = int.MinValue;
foreach (var ie in node.Outs)
{
if (!localVarToLocalVariableInfo.ContainsKey(ie.Decl))
{
continue;
}
if (inferredLayer < localVarToLocalVariableInfo[ie.Decl].layer)
{
inferredLayer = localVarToLocalVariableInfo[ie.Decl].layer;
}
}
pureCallLayer[node] = inferredLayer;
if (inferredLayer != int.MinValue)
{
foreach (var ie in node.Outs)
{
if (!localVarToLocalVariableInfo.ContainsKey(ie.Decl))
{
Error(node, "Output variable must be introduced");
}
else if (inferredLayer != localVarToLocalVariableInfo[ie.Decl].layer)
{
Error(node, "All output variables must be introduced at the same layer");
}
}
}
Debug.Assert(introducedLocalVarsUpperBound == int.MinValue);
foreach (var e in node.Ins)
{
Visit(e);
if (inferredLayer < introducedLocalVarsUpperBound)
{
Error(node, "An introduced local variable is not accessible");
}
introducedLocalVarsUpperBound = int.MinValue;
}
}
else
{
Debug.Assert(introducedLocalVarsUpperBound == int.MinValue);
int inferredLayer = int.MinValue;
foreach (var e in node.Ins)
{
Visit(e);
if (inferredLayer < introducedLocalVarsUpperBound)
{
inferredLayer = introducedLocalVarsUpperBound;
}
introducedLocalVarsUpperBound = int.MinValue;
}
pureCallLayer[node] = inferredLayer;
}
}
else
{
if (enclosingProcLayerNum != atomicProcedureInfo.layerRange.upperLayerNum)
{
Error(node, "Creation layer of caller must be the upper bound of the layer range of callee");
}
foreach (var ie in node.Proc.Modifies)
{
if (enclosingProcLayerNum != globalVarToSharedVarInfo[ie.Decl].introLayerNum)
{
Error(node, "Creation layer of caller must be identical to the introduction layer of modified variable");
}
}
foreach (var ie in node.Outs)
{
if (localVarToLocalVariableInfo.ContainsKey(ie.Decl) &&
enclosingProcLayerNum == localVarToLocalVariableInfo[ie.Decl].layer)
{
continue;
}
Error(node, "Output variable must be introduced at the creation layer of caller");
}
}
return(node);
}
else
{
Error(node, "A yielding procedure can call only atomic or yielding procedures");
return(node);
}
}
public void TypeCheck()
{
// Pure procedures
foreach (var proc in program.Procedures.Where(proc => proc.IsPure()))
{
if (proc.IsYield())
{
Error(proc, "Pure procedure must not yield");
continue;
}
if (FindLayers(proc.Attributes).Count != 0)
{
Error(proc, "Pure procedure must not have layers");
continue;
}
if (proc.Modifies.Count > 0)
{
Error(proc, "Pure procedure must not modify a global variable");
continue;
}
procToAtomicProcedureInfo[proc] = new AtomicProcedureInfo();
}
// Atomic procedures (not yielding)
foreach (var proc in program.Procedures.Where(proc => !proc.IsYield()))
{
var procLayerNums = FindLayers(proc.Attributes);
if (procLayerNums.Count == 0) continue;
foreach (IdentifierExpr ie in proc.Modifies)
{
if (!globalVarToSharedVarInfo.ContainsKey(ie.Decl))
{
Error(proc, "Atomic procedure cannot modify a global variable without layer numbers");
continue;
}
}
int lower, upper;
if (procLayerNums.Count == 1)
{
lower = procLayerNums[0];
upper = procLayerNums[0];
}
else if (procLayerNums.Count == 2)
{
lower = procLayerNums[0];
upper = procLayerNums[1];
if (lower >= upper)
{
Error(proc, "Lower layer must be less than upper layer");
continue;
}
}
else
{
Error(proc, "Atomic procedure must specify a layer range");
continue;
}
LayerRange layerRange = new LayerRange(lower, upper);
procToAtomicProcedureInfo[proc] = new AtomicProcedureInfo(layerRange);
}
if (errorCount > 0) return;
// Implementations of atomic procedures
foreach (Implementation impl in program.Implementations)
{
AtomicProcedureInfo atomicProcedureInfo;
if (!procToAtomicProcedureInfo.TryGetValue(impl.Proc, out atomicProcedureInfo)) continue;
if (atomicProcedureInfo.isPure)
{
this.enclosingImpl = impl;
(new PurityChecker(this)).VisitImplementation(impl);
}
else
{
this.enclosingImpl = impl;
this.sharedVarsAccessed = new HashSet<Variable>();
(new PurityChecker(this)).VisitImplementation(impl);
LayerRange upperBound = FindLayerRange();
LayerRange lowerBound = atomicProcedureInfo.layerRange;
if (!lowerBound.Subset(upperBound))
{
Error(impl, "Atomic procedure cannot access global variable");
}
this.sharedVarsAccessed = null;
}
}
if (errorCount > 0) return;
// Yielding procedures
foreach (var proc in program.Procedures.Where(proc => proc.IsYield()))
{
int createdAtLayerNum; // must be initialized by the following code, otherwise it is an error
int availableUptoLayerNum = int.MaxValue;
List<int> attrs = FindLayers(proc.Attributes);
if (attrs.Count == 1)
{
createdAtLayerNum = attrs[0];
}
else if (attrs.Count == 2)
{
createdAtLayerNum = attrs[0];
availableUptoLayerNum = attrs[1];
}
else
{
Error(proc, "Incorrect number of layers");
continue;
}
foreach (Ensures e in proc.Ensures)
{
MoverType moverType = GetMoverType(e);
if (moverType == MoverType.Top) continue;
CodeExpr codeExpr = e.Condition as CodeExpr;
if (codeExpr == null)
{
Error(e, "An atomic action must be a CodeExpr");
continue;
}
if (procToActionInfo.ContainsKey(proc))
{
Error(proc, "A procedure can have at most one atomic action");
continue;
}
if (availableUptoLayerNum <= createdAtLayerNum)
{
Error(proc, "Creation layer number must be less than the available upto layer number");
continue;
}
sharedVarsAccessed = new HashSet<Variable>();
enclosingProc = proc;
enclosingImpl = null;
base.VisitEnsures(e);
LayerRange upperBound = FindLayerRange();
LayerRange lowerBound = new LayerRange(createdAtLayerNum, availableUptoLayerNum);
if (lowerBound.Subset(upperBound))
{
procToActionInfo[proc] = new AtomicActionInfo(proc, e, moverType, createdAtLayerNum, availableUptoLayerNum);
}
else
{
Error(e, "A variable being accessed in this action is unavailable");
}
sharedVarsAccessed = null;
}
if (errorCount > 0) continue;
if (!procToActionInfo.ContainsKey(proc))
{
if (availableUptoLayerNum < createdAtLayerNum)
{
Error(proc, "Creation layer number must be no more than the available upto layer number");
continue;
}
else
{
procToActionInfo[proc] = new ActionInfo(proc, createdAtLayerNum, availableUptoLayerNum);
}
}
}
if (errorCount > 0) return;
foreach (var impl in program.Implementations)
{
if (!procToActionInfo.ContainsKey(impl.Proc)) continue;
ActionInfo actionInfo = procToActionInfo[impl.Proc];
procToActionInfo[impl.Proc].hasImplementation = true;
if (actionInfo.isExtern)
{
Error(impl.Proc, "Extern procedure cannot have an implementation");
}
}
if (errorCount > 0) return;
foreach (Procedure proc in procToActionInfo.Keys)
{
for (int i = 0; i < proc.InParams.Count; i++)
{
Variable v = proc.InParams[i];
var layer = FindLocalVariableLayer(proc, v, procToActionInfo[proc].createdAtLayerNum);
if (layer == int.MinValue) continue;
localVarToLocalVariableInfo[v] = new LocalVariableInfo(layer);
}
for (int i = 0; i < proc.OutParams.Count; i++)
{
Variable v = proc.OutParams[i];
var layer = FindLocalVariableLayer(proc, v, procToActionInfo[proc].createdAtLayerNum);
if (layer == int.MinValue) continue;
localVarToLocalVariableInfo[v] = new LocalVariableInfo(layer);
}
}
foreach (Implementation node in program.Implementations)
{
if (!procToActionInfo.ContainsKey(node.Proc)) continue;
foreach (Variable v in node.LocVars)
{
var layer = FindLocalVariableLayer(node, v, procToActionInfo[node.Proc].createdAtLayerNum);
if (layer == int.MinValue) continue;
localVarToLocalVariableInfo[v] = new LocalVariableInfo(layer);
}
for (int i = 0; i < node.Proc.InParams.Count; i++)
{
Variable v = node.Proc.InParams[i];
if (!localVarToLocalVariableInfo.ContainsKey(v)) continue;
var layer = localVarToLocalVariableInfo[v].layer;
localVarToLocalVariableInfo[node.InParams[i]] = new LocalVariableInfo(layer);
}
for (int i = 0; i < node.Proc.OutParams.Count; i++)
{
Variable v = node.Proc.OutParams[i];
if (!localVarToLocalVariableInfo.ContainsKey(v)) continue;
var layer = localVarToLocalVariableInfo[v].layer;
localVarToLocalVariableInfo[node.OutParams[i]] = new LocalVariableInfo(layer);
}
}
if (errorCount > 0) return;
this.VisitProgram(program);
if (errorCount > 0) return;
YieldTypeChecker.PerformYieldSafeCheck(this);
new LayerEraser().VisitProgram(program);
}
private void CreateCommutativityChecker(Program program, ActionInfo first, ActionInfo second)
{
Tuple<ActionInfo, ActionInfo> actionPair = new Tuple<ActionInfo, ActionInfo>(first, second);
if (commutativityCheckerCache.Contains(actionPair))
return;
commutativityCheckerCache.Add(actionPair);
List<Variable> inputs = new List<Variable>();
inputs.AddRange(first.thisInParams);
inputs.AddRange(second.thatInParams);
List<Variable> outputs = new List<Variable>();
outputs.AddRange(first.thisOutParams);
outputs.AddRange(second.thatOutParams);
List<Variable> locals = new List<Variable>();
locals.AddRange(first.thisAction.LocVars);
locals.AddRange(second.thatAction.LocVars);
List<Block> firstBlocks = CloneBlocks(first.thisAction.Blocks);
List<Block> secondBlocks = CloneBlocks(second.thatAction.Blocks);
foreach (Block b in firstBlocks)
{
if (b.TransferCmd is ReturnCmd)
{
List<Block> bs = new List<Block>();
bs.Add(secondBlocks[0]);
List<string> ls = new List<string>();
ls.Add(secondBlocks[0].Label);
b.TransferCmd = new GotoCmd(Token.NoToken, ls, bs);
}
}
List<Block> blocks = new List<Block>();
blocks.AddRange(firstBlocks);
blocks.AddRange(secondBlocks);
List<Requires> requires = DisjointnessRequires(program, first, second);
List<Ensures> ensures = new List<Ensures>();
Expr transitionRelation = (new TransitionRelationComputation(program, first, second)).Compute();
ensures.Add(new Ensures(false, transitionRelation));
string checkerName = string.Format("CommutativityChecker_{0}_{1}", first.proc.Name, second.proc.Name);
List<IdentifierExpr> globalVars = new List<IdentifierExpr>();
program.GlobalVariables().Iter(x => globalVars.Add(new IdentifierExpr(Token.NoToken, x)));
Procedure proc = new Procedure(Token.NoToken, checkerName, new List<TypeVariable>(), inputs, outputs, requires, globalVars, ensures);
Implementation impl = new Implementation(Token.NoToken, checkerName, new List<TypeVariable>(), inputs, outputs, locals, blocks);
impl.Proc = proc;
this.decls.Add(impl);
this.decls.Add(proc);
}
public void TypeCheck()
{
foreach (Declaration decl in program.TopLevelDeclarations)
{
Procedure proc = decl as Procedure;
if (proc == null) continue;
foreach (Ensures e in proc.Ensures)
{
int phaseNum;
MoverType moverType = MoverCheck.GetMoverType(e, out phaseNum);
if (moverType == MoverType.Top) continue;
CodeExpr codeExpr = e.Condition as CodeExpr;
if (codeExpr == null)
{
Error(e, "An atomic action must be a CodeExpr");
continue;
}
if (procToActionInfo.ContainsKey(proc))
{
Error(proc, "A procedure can have at most one atomic action");
continue;
}
procToActionInfo[proc] = new ActionInfo(proc, codeExpr, moverType, phaseNum);
}
}
this.VisitProgram(program);
#if QED
YieldTypeChecker.PerformYieldTypeChecking(this);
#endif
}
public TransitionRelationComputation(Program program, ActionInfo first, ActionInfo second)
{
this.program = program;
this.first = first;
this.second = second;
this.dfsStack = new Stack<Block>();
this.transitionRelation = Expr.False;
this.boundVariableCount = 0;
}
private List<Requires> DisjointnessRequires(Program program, ActionInfo first, ActionInfo second)
{
List<Requires> requires = new List<Requires>();
Dictionary<string, HashSet<Variable>> domainNameToScope = new Dictionary<string, HashSet<Variable>>();
foreach (var domainName in linearTypeChecker.linearDomains.Keys)
{
domainNameToScope[domainName] = new HashSet<Variable>();
}
foreach (Variable v in program.GlobalVariables())
{
var domainName = linearTypeChecker.FindDomainName(v);
if (domainName == null) continue;
domainNameToScope[domainName].Add(v);
}
foreach (Variable v in first.thisInParams)
{
var domainName = linearTypeChecker.FindDomainName(v);
if (domainName == null) continue;
domainNameToScope[domainName].Add(v);
}
for (int i = 0; i < second.thatInParams.Count; i++)
{
var domainName = linearTypeChecker.FindDomainName(second.thisInParams[i]);
if (domainName == null) continue;
domainNameToScope[domainName].Add(second.thatInParams[i]);
}
foreach (string domainName in domainNameToScope.Keys)
{
requires.Add(new Requires(false, linearTypeChecker.DisjointnessExpr(domainName, domainNameToScope[domainName])));
}
return requires;
}
private void CreateGatePreservationChecker(Program program, ActionInfo first, ActionInfo second)
{
Tuple<ActionInfo, ActionInfo> actionPair = new Tuple<ActionInfo, ActionInfo>(first, second);
if (gatePreservationCheckerCache.Contains(actionPair))
return;
gatePreservationCheckerCache.Add(actionPair);
List<Variable> inputs = new List<Variable>();
inputs.AddRange(first.thisInParams);
inputs.AddRange(second.thatInParams);
List<Variable> outputs = new List<Variable>();
outputs.AddRange(first.thisOutParams);
outputs.AddRange(second.thatOutParams);
List<Variable> locals = new List<Variable>();
locals.AddRange(second.thatAction.LocVars);
List<Block> secondBlocks = CloneBlocks(second.thatAction.Blocks);
List<Requires> requires = DisjointnessRequires(program, first, second);
List<Ensures> ensures = new List<Ensures>();
foreach (AssertCmd assertCmd in first.thisGate)
{
requires.Add(new Requires(false, assertCmd.Expr));
ensures.Add(new Ensures(false, assertCmd.Expr));
}
string checkerName = string.Format("GatePreservationChecker_{0}_{1}", first.proc.Name, second.proc.Name);
List<IdentifierExpr> globalVars = new List<IdentifierExpr>();
program.GlobalVariables().Iter(x => globalVars.Add(new IdentifierExpr(Token.NoToken, x)));
Procedure proc = new Procedure(Token.NoToken, checkerName, new List<TypeVariable>(), inputs, outputs, requires, globalVars, ensures);
Implementation impl = new Implementation(Token.NoToken, checkerName, new List<TypeVariable>(), inputs, outputs, locals, secondBlocks);
impl.Proc = proc;
this.decls.Add(impl);
this.decls.Add(proc);
}
private void CreateFailurePreservationChecker(Program program, ActionInfo first, ActionInfo second)
{
Tuple<ActionInfo, ActionInfo> actionPair = new Tuple<ActionInfo, ActionInfo>(first, second);
if (failurePreservationCheckerCache.Contains(actionPair))
return;
failurePreservationCheckerCache.Add(actionPair);
List<Variable> inputs = new List<Variable>();
inputs.AddRange(first.thisInParams);
inputs.AddRange(second.thatInParams);
Expr transitionRelation = (new TransitionRelationComputation(program, second)).Compute();
Expr expr = Expr.True;
foreach (AssertCmd assertCmd in first.thisGate)
{
expr = Expr.And(assertCmd.Expr, expr);
}
List<Requires> requires = DisjointnessRequires(program, first, second);
requires.Add(new Requires(false, Expr.Not(expr)));
foreach (AssertCmd assertCmd in second.thatGate)
{
requires.Add(new Requires(false, assertCmd.Expr));
}
Dictionary<Variable, Expr> map = new Dictionary<Variable, Expr>();
Dictionary<Variable, Expr> oldMap = new Dictionary<Variable, Expr>();
List<Variable> boundVars = new List<Variable>();
foreach (Variable v in program.GlobalVariables())
{
BoundVariable bv = new BoundVariable(Token.NoToken, new TypedIdent(Token.NoToken, "post_" + v.Name, v.TypedIdent.Type));
boundVars.Add(bv);
map[v] = new IdentifierExpr(Token.NoToken, bv);
}
foreach (Variable v in second.thatOutParams)
{
{
BoundVariable bv = new BoundVariable(Token.NoToken, new TypedIdent(Token.NoToken, "post_" + v.Name, v.TypedIdent.Type));
boundVars.Add(bv);
map[v] = new IdentifierExpr(Token.NoToken, bv);
}
{
BoundVariable bv = new BoundVariable(Token.NoToken, new TypedIdent(Token.NoToken, "pre_" + v.Name, v.TypedIdent.Type));
boundVars.Add(bv);
oldMap[v] = new IdentifierExpr(Token.NoToken, bv);
}
}
foreach (Variable v in second.thatAction.LocVars)
{
BoundVariable bv = new BoundVariable(Token.NoToken, new TypedIdent(Token.NoToken, "pre_" + v.Name, v.TypedIdent.Type));
boundVars.Add(bv);
oldMap[v] = new IdentifierExpr(Token.NoToken, bv);
}
Expr ensuresExpr = Expr.And(transitionRelation, Expr.Not(expr));
if (boundVars.Count > 0)
{
Substitution subst = Substituter.SubstitutionFromHashtable(map);
Substitution oldSubst = Substituter.SubstitutionFromHashtable(oldMap);
ensuresExpr = new ExistsExpr(Token.NoToken, boundVars, (Expr)new MySubstituter(subst, oldSubst).Visit(ensuresExpr));
}
List<Ensures> ensures = new List<Ensures>();
ensures.Add(new Ensures(false, ensuresExpr));
List<Block> blocks = new List<Block>();
blocks.Add(new Block(Token.NoToken, "L", new List<Cmd>(), new ReturnCmd(Token.NoToken)));
string checkerName = string.Format("FailurePreservationChecker_{0}_{1}", first.proc.Name, second.proc.Name);
List<IdentifierExpr> globalVars = new List<IdentifierExpr>();
program.GlobalVariables().Iter(x => globalVars.Add(new IdentifierExpr(Token.NoToken, x)));
Procedure proc = new Procedure(Token.NoToken, checkerName, new List<TypeVariable>(), inputs, new List<Variable>(), requires, globalVars, ensures);
Implementation impl = new Implementation(Token.NoToken, checkerName, new List<TypeVariable>(), inputs, new List<Variable>(), new List<Variable>(), blocks);
impl.Proc = proc;
this.decls.Add(impl);
this.decls.Add(proc);
}
private void ComputeGraph()
{
foreach (Block block in impl.Blocks)
{
for (int i = 0; i < block.Cmds.Count; i++)
{
Cmd cmd = block.Cmds[i];
int curr = absyToNode[cmd];
int next = (i + 1 == block.Cmds.Count) ? absyToNode[block.TransferCmd] : absyToNode[block.Cmds[i + 1]];
Tuple <int, int> edge = new Tuple <int, int>(curr, next);
if (cmd is CallCmd)
{
CallCmd callCmd = cmd as CallCmd;
if (callCmd.IsAsync)
{
ActionInfo actionInfo = moverTypeChecker.procToActionInfo[callCmd.Proc];
if (currLayerNum <= actionInfo.createdAtLayerNum)
{
edgeLabels[edge] = 'L';
}
else
{
edgeLabels[edge] = 'B';
}
}
else if (!moverTypeChecker.procToActionInfo.ContainsKey(callCmd.Proc))
{
edgeLabels[edge] = 'P';
}
else
{
MoverType moverType;
ActionInfo actionInfo = moverTypeChecker.procToActionInfo[callCmd.Proc];
if (actionInfo.createdAtLayerNum >= currLayerNum)
{
moverType = MoverType.Top;
}
else
{
AtomicActionInfo atomicActionInfo = actionInfo as AtomicActionInfo;
if (atomicActionInfo == null)
{
moverType = MoverType.Both;
}
else
{
moverType = atomicActionInfo.moverType;
}
}
switch (moverType)
{
case MoverType.Atomic:
edgeLabels[edge] = 'A';
break;
case MoverType.Both:
edgeLabels[edge] = 'B';
break;
case MoverType.Left:
edgeLabels[edge] = 'L';
break;
case MoverType.Right:
edgeLabels[edge] = 'R';
break;
case MoverType.Top:
edgeLabels[edge] = 'Y';
break;
}
}
}
else if (cmd is ParCallCmd)
{
ParCallCmd parCallCmd = cmd as ParCallCmd;
bool isYield = false;
bool isRightMover = true;
bool isLeftMover = true;
foreach (CallCmd callCmd in parCallCmd.CallCmds)
{
if (moverTypeChecker.procToActionInfo[callCmd.Proc].createdAtLayerNum >= currLayerNum)
{
isYield = true;
}
}
if (isYield)
{
edgeLabels[edge] = 'Y';
}
else
{
foreach (CallCmd callCmd in parCallCmd.CallCmds)
{
ActionInfo actionInfo = moverTypeChecker.procToActionInfo[callCmd.Proc];
isRightMover = isRightMover && actionInfo.IsRightMover;
isLeftMover = isLeftMover && actionInfo.IsLeftMover;
}
if (isLeftMover && isRightMover)
{
edgeLabels[edge] = 'B';
}
else if (isLeftMover)
{
edgeLabels[edge] = 'L';
}
else if (isRightMover)
{
edgeLabels[edge] = 'R';
}
else
{
Debug.Assert(parCallCmd.CallCmds.Count == 1);
edgeLabels[edge] = 'A';
}
}
}
else if (cmd is YieldCmd)
{
edgeLabels[edge] = 'Y';
}
else
{
edgeLabels[edge] = 'P';
}
}
}
}
public void TypeCheck()
{
foreach (var proc in program.Procedures)
{
if (!QKeyValue.FindBoolAttribute(proc.Attributes, "pure")) continue;
if (QKeyValue.FindBoolAttribute(proc.Attributes, "yields"))
{
Error(proc, "Pure procedure must not yield");
continue;
}
if (QKeyValue.FindBoolAttribute(proc.Attributes, "layer"))
{
Error(proc, "Pure procedure must not have layers");
continue;
}
if (proc.Modifies.Count > 0)
{
Error(proc, "Pure procedure must not modify a global variable");
continue;
}
procToAtomicProcedureInfo[proc] = new AtomicProcedureInfo();
}
foreach (var proc in program.Procedures)
{
if (QKeyValue.FindBoolAttribute(proc.Attributes, "yields")) continue;
var procLayerNums = RemoveDuplicatesAndSort(FindLayers(proc.Attributes));
if (procLayerNums.Count == 0) continue;
foreach (IdentifierExpr ie in proc.Modifies)
{
if (!globalVarToSharedVarInfo.ContainsKey(ie.Decl))
{
Error(proc, "Atomic procedure cannot modify a global variable without layer numbers");
}
else if (globalVarToSharedVarInfo[ie.Decl].introLayerNum != procLayerNums[0])
{
Error(proc, "The introduction layer of a modified global variable must be identical to the layer of the atomic procedure");
}
}
if (proc.Modifies.Count == 0 || procLayerNums.Count == 1)
{
procToAtomicProcedureInfo[proc] = new AtomicProcedureInfo(new HashSet<int>(procLayerNums));
}
else
{
Error(proc, "An atomic procedure with more than one layer must not modify a global variable");
}
}
if (errorCount > 0) return;
foreach (Implementation impl in program.Implementations)
{
if (!procToAtomicProcedureInfo.ContainsKey(impl.Proc)) continue;
var atomicProcedureInfo = procToAtomicProcedureInfo[impl.Proc];
if (atomicProcedureInfo.isPure)
{
this.enclosingImpl = impl;
(new PurityChecker(this)).VisitImplementation(impl);
}
else
{
this.enclosingImpl = impl;
this.sharedVarsAccessed = new HashSet<Variable>();
(new PurityChecker(this)).VisitImplementation(impl);
LayerRange upperBound = FindLayerRange();
LayerRange lowerBound = new LayerRange(atomicProcedureInfo.layers);
if (!lowerBound.Subset(upperBound))
{
Error(impl, "Atomic procedure cannot access global variable");
}
this.sharedVarsAccessed = null;
}
}
if (errorCount > 0) return;
foreach (var proc in program.Procedures)
{
if (!QKeyValue.FindBoolAttribute(proc.Attributes, "yields")) continue;
int createdAtLayerNum; // must be initialized by the following code, otherwise it is an error
int availableUptoLayerNum = int.MaxValue;
List<int> attrs = FindLayers(proc.Attributes);
if (attrs.Count == 1)
{
createdAtLayerNum = attrs[0];
}
else if (attrs.Count == 2)
{
createdAtLayerNum = attrs[0];
availableUptoLayerNum = attrs[1];
}
else
{
Error(proc, "Incorrect number of layers");
continue;
}
foreach (Ensures e in proc.Ensures)
{
MoverType moverType = GetMoverType(e);
if (moverType == MoverType.Top) continue;
CodeExpr codeExpr = e.Condition as CodeExpr;
if (codeExpr == null)
{
Error(e, "An atomic action must be a CodeExpr");
continue;
}
if (procToActionInfo.ContainsKey(proc))
{
Error(proc, "A procedure can have at most one atomic action");
continue;
}
if (availableUptoLayerNum <= createdAtLayerNum)
{
Error(proc, "Creation layer number must be less than the available upto layer number");
continue;
}
sharedVarsAccessed = new HashSet<Variable>();
enclosingProc = proc;
enclosingImpl = null;
base.VisitEnsures(e);
LayerRange upperBound = FindLayerRange();
LayerRange lowerBound = new LayerRange(createdAtLayerNum, availableUptoLayerNum);
if (lowerBound.Subset(upperBound))
{
procToActionInfo[proc] = new AtomicActionInfo(proc, e, moverType, createdAtLayerNum, availableUptoLayerNum);
}
else
{
Error(e, "A variable being accessed in this action is unavailable");
}
sharedVarsAccessed = null;
}
if (errorCount > 0) continue;
if (!procToActionInfo.ContainsKey(proc))
{
if (availableUptoLayerNum < createdAtLayerNum)
{
Error(proc, "Creation layer number must be no more than the available upto layer number");
continue;
}
else
{
procToActionInfo[proc] = new ActionInfo(proc, createdAtLayerNum, availableUptoLayerNum);
}
}
}
if (errorCount > 0) return;
foreach (Implementation node in program.Implementations)
{
if (!procToActionInfo.ContainsKey(node.Proc)) continue;
foreach (Variable v in node.LocVars)
{
var layer = FindLocalVariableLayer(node, v, procToActionInfo[node.Proc].createdAtLayerNum);
if (layer == int.MinValue) continue;
localVarToLocalVariableInfo[v] = new LocalVariableInfo(QKeyValue.FindBoolAttribute(node.Attributes, "ghost"), layer);
}
for (int i = 0; i < node.Proc.InParams.Count; i++)
{
Variable v = node.Proc.InParams[i];
var layer = FindLocalVariableLayer(node.Proc, v, procToActionInfo[node.Proc].createdAtLayerNum);
if (layer == int.MinValue) continue;
localVarToLocalVariableInfo[v] = new LocalVariableInfo(false, layer);
localVarToLocalVariableInfo[node.InParams[i]] = new LocalVariableInfo(false, layer);
}
for (int i = 0; i < node.Proc.OutParams.Count; i++)
{
Variable v = node.Proc.OutParams[i];
var layer = FindLocalVariableLayer(node.Proc, v, procToActionInfo[node.Proc].createdAtLayerNum);
if (layer == int.MinValue) continue;
localVarToLocalVariableInfo[v] = new LocalVariableInfo(false, layer);
localVarToLocalVariableInfo[node.OutParams[i]] = new LocalVariableInfo(false, layer);
}
}
if (errorCount > 0) return;
foreach (var impl in program.Implementations)
{
if (!procToActionInfo.ContainsKey(impl.Proc)) continue;
ActionInfo actionInfo = procToActionInfo[impl.Proc];
procToActionInfo[impl.Proc].hasImplementation = true;
if (actionInfo.isExtern)
{
Error(impl.Proc, "Extern procedure cannot have an implementation");
}
}
foreach (var g in this.globalVarToSharedVarInfo.Keys)
{
var info = globalVarToSharedVarInfo[g];
if (!this.AllCreatedLayerNums.Contains(info.introLayerNum))
{
Error(g, "Variable must be introduced with creation of some atomic action");
}
if (info.hideLayerNum != int.MaxValue && !this.AllCreatedLayerNums.Contains(info.hideLayerNum))
{
Error(g, "Variable must be hidden with creation of some atomic action");
}
}
if (errorCount > 0) return;
this.VisitProgram(program);
if (errorCount > 0) return;
YieldTypeChecker.PerformYieldSafeCheck(this);
new LayerEraser().VisitProgram(program);
}