protected override bool LocalFunctionEnd(
LocalFunctionState savedState,
LocalFunctionState currentState,
ref LocalState stateAtReturn
)
{
if (currentState.CapturedMask.IsNull)
{
currentState.CapturedMask = GetCapturedBitmask();
currentState.InvertedCapturedMask = currentState.CapturedMask.Clone();
currentState.InvertedCapturedMask.Invert();
}
// Filter the modified state variables to only captured variables
stateAtReturn.Assigned.IntersectWith(currentState.CapturedMask);
if (NonMonotonicState.HasValue)
{
var state = NonMonotonicState.Value;
state.Assigned.UnionWith(currentState.InvertedCapturedMask);
NonMonotonicState = state;
}
// Build a list of variables that are both captured and read before assignment
var capturedAndRead = currentState.ReadVars;
capturedAndRead.IntersectWith(currentState.CapturedMask);
// Union and check to see if there are any changes
return(savedState.ReadVars.UnionWith(capturedAndRead));
}
/// <summary>
/// State changes are handled by the base class. We override to find captured variables that
/// have been read before they were assigned and determine if the set has changed.
/// </summary>
protected override bool LocalFunctionEnd(
LocalFunctionState savedState,
LocalFunctionState currentState,
ref LocalState stateAtReturn)
{
// Build a list of variables that are both captured and read before assignment
var capturedMask = GetCapturedBitmask(ref currentState.ReadVars);
var capturedAndRead = currentState.ReadVars;
capturedAndRead.IntersectWith(capturedMask);
// Union and check to see if there are any changes
return(savedState.ReadVars.UnionWith(capturedAndRead));
}
protected override LocalFunctionState LocalFunctionStart(LocalFunctionState startState)
{
// Captured variables are definitely assigned if they are assigned on
// all branches into the local function, so we store all reads from
// possibly unassigned captured variables and later report definite
// assignment errors if any of the captured variables is not assigned
// on a particular branch.
var savedState = new LocalFunctionState(UnreachableState());
savedState.ReadVars = startState.ReadVars.Clone();
startState.ReadVars.Clear();
return(savedState);
}
/// <summary>
/// At the local function's use site, checks that all variables read are assigned.
/// </summary>
protected override void VisitLocalFunctionUse(LocalFunctionSymbol localFunc, LocalFunctionState localFunctionState, SyntaxNode syntax)
{
_usedLocalFunctions.Add(localFunc);
var reads = localFunctionState.ReadVars;
// Start at slot 1 (slot 0 just indicates reachability)
for (int slot = 1; slot < reads.Capacity; slot++)
{
if (reads[slot])
{
var symbol = variableBySlot[slot].Symbol;
CheckIfAssignedDuringLocalFunctionReplay(symbol, syntax, slot);
}
}
}
protected override void VisitLocalFunctionUse(
LocalFunctionSymbol localFunc,
LocalFunctionState localFunctionState,
SyntaxNode syntax,
bool isCall)
{
_usedLocalFunctions.Add(localFunc);
// Check variables that were read before being definitely assigned.
var reads = localFunctionState.ReadVars;
// Start at slot 1 (slot 0 just indicates reachability)
for (int slot = 1; slot < reads.Capacity; slot++)
{
if (reads[slot])
{
var symbol = variableBySlot[slot].Symbol;
CheckIfAssignedDuringLocalFunctionReplay(symbol, syntax, slot);
}
}
base.VisitLocalFunctionUse(localFunc, localFunctionState, syntax, isCall);
}
