public AwaitFinallyFrame(AwaitFinallyFrame parent, HashSet <LabelSymbol> labelsOpt, SyntaxNode syntax)
{
Debug.Assert(parent != null);
Debug.Assert(syntax != null);
Debug.Assert(SyntaxBindingUtilities.BindsToTryStatement(syntax));
this.ParentOpt = parent;
this.LabelsOpt = labelsOpt;
_syntaxOpt = syntax;
}
public StateMachineState AllocateState(SyntaxNode awaitOrYieldReturnSyntax)
{
Debug.Assert(SyntaxBindingUtilities.BindsToResumableStateMachineState(awaitOrYieldReturnSyntax));
int direction = _increasing ? +1 : -1;
if (_slotAllocator?.TryGetPreviousStateMachineState(awaitOrYieldReturnSyntax, out var state) == true)
{
#if DEBUG
// two states of the new state machine should not match the same state of the previous machine:
Debug.Assert(!_matchedStates[(int)state * direction]);
_matchedStates[(int)state * direction] = true;
#endif
_matchedStateCount++;
}
else
{
state = _nextState;
_nextState += direction;
}
return(state);
}
public override BoundNode VisitTryStatement(BoundTryStatement node)
{
var tryStatementSyntax = node.Syntax;
// If you add a syntax kind to the assertion below, please also ensure
// that the scenario has been tested with Edit-and-Continue.
Debug.Assert(SyntaxBindingUtilities.BindsToTryStatement(tryStatementSyntax));
BoundStatement finalizedRegion;
BoundBlock rewrittenFinally;
var finallyContainsAwaits = _analysis.FinallyContainsAwaits(node);
if (!finallyContainsAwaits)
{
finalizedRegion = RewriteFinalizedRegion(node);
rewrittenFinally = (BoundBlock)this.Visit(node.FinallyBlockOpt);
if (rewrittenFinally == null)
{
return(finalizedRegion);
}
var asTry = finalizedRegion as BoundTryStatement;
if (asTry != null)
{
// since finalized region is a try we can just attach finally to it
Debug.Assert(asTry.FinallyBlockOpt == null);
return(asTry.Update(asTry.TryBlock, asTry.CatchBlocks, rewrittenFinally, asTry.FinallyLabelOpt, asTry.PreferFaultHandler));
}
else
{
// wrap finalizedRegion into a Try with a finally.
return(_F.Try((BoundBlock)finalizedRegion, ImmutableArray <BoundCatchBlock> .Empty, rewrittenFinally));
}
}
// rewrite finalized region (try and catches) in the current frame
var frame = PushFrame(node);
finalizedRegion = RewriteFinalizedRegion(node);
rewrittenFinally = (BoundBlock)this.VisitBlock(node.FinallyBlockOpt);
PopFrame();
var exceptionType = _F.SpecialType(SpecialType.System_Object);
var pendingExceptionLocal = new SynthesizedLocal(_F.CurrentFunction, TypeWithAnnotations.Create(exceptionType), SynthesizedLocalKind.TryAwaitPendingException, tryStatementSyntax);
var finallyLabel = _F.GenerateLabel("finallyLabel");
var pendingBranchVar = new SynthesizedLocal(_F.CurrentFunction, TypeWithAnnotations.Create(_F.SpecialType(SpecialType.System_Int32)), SynthesizedLocalKind.TryAwaitPendingBranch, tryStatementSyntax);
var catchAll = _F.Catch(_F.Local(pendingExceptionLocal), _F.Block());
var catchAndPendException = _F.Try(
_F.Block(
finalizedRegion,
_F.HiddenSequencePoint(),
_F.Goto(finallyLabel),
PendBranches(frame, pendingBranchVar, finallyLabel)),
ImmutableArray.Create(catchAll),
finallyLabel: finallyLabel);
BoundBlock syntheticFinallyBlock = _F.Block(
_F.HiddenSequencePoint(),
_F.Label(finallyLabel),
rewrittenFinally,
_F.HiddenSequencePoint(),
UnpendException(pendingExceptionLocal),
UnpendBranches(
frame,
pendingBranchVar,
pendingExceptionLocal));
BoundStatement syntheticFinally = syntheticFinallyBlock;
if (_F.CurrentFunction.IsAsync && _F.CurrentFunction.IsIterator)
{
// We wrap this block so that it can be processed as a finally block by async-iterator rewriting
syntheticFinally = _F.ExtractedFinallyBlock(syntheticFinallyBlock);
}
var locals = ArrayBuilder <LocalSymbol> .GetInstance();
var statements = ArrayBuilder <BoundStatement> .GetInstance();
statements.Add(_F.HiddenSequencePoint());
locals.Add(pendingExceptionLocal);
statements.Add(_F.Assignment(_F.Local(pendingExceptionLocal), _F.Default(pendingExceptionLocal.Type)));
locals.Add(pendingBranchVar);
statements.Add(_F.Assignment(_F.Local(pendingBranchVar), _F.Default(pendingBranchVar.Type)));
LocalSymbol returnLocal = frame.returnValue;
if (returnLocal != null)
{
locals.Add(returnLocal);
}
statements.Add(catchAndPendException);
statements.Add(syntheticFinally);
var completeTry = _F.Block(
locals.ToImmutableAndFree(),
statements.ToImmutableAndFree());
return(completeTry);
}
