public override BoundNode VisitTryStatement(BoundTryStatement node)
{
var tryStatementSyntax = node.Syntax;
Debug.Assert(tryStatementSyntax.IsKind(SyntaxKind.TryStatement));
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.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.CurrentMethod, exceptionType, SynthesizedLocalKind.TryAwaitPendingException, tryStatementSyntax);
var finallyLabel = _F.GenerateLabel("finallyLabel");
var pendingBranchVar = new SynthesizedLocal(_F.CurrentMethod, _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));
var syntheticFinally = _F.Block(
_F.HiddenSequencePoint(),
_F.Label(finallyLabel),
rewrittenFinally,
_F.HiddenSequencePoint(),
UnpendException(pendingExceptionLocal),
UnpendBranches(
frame,
pendingBranchVar,
pendingExceptionLocal));
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);
}
private BoundStatement UnpendBranches(
AwaitFinallyFrame frame,
SynthesizedLocal pendingBranchVar,
SynthesizedLocal pendingException)
{
var parent = frame.ParentOpt;
// handle proxy labels if have any
var proxiedLabels = frame.proxiedLabels;
var proxyLabels = frame.proxyLabels;
// skip 0 - it means we took no explicit branches
int i = 1;
var cases = ArrayBuilder <BoundSwitchSection> .GetInstance();
if (proxiedLabels != null)
{
for (int cnt = proxiedLabels.Count; i <= cnt; i++)
{
var target = proxiedLabels[i - 1];
var parentProxy = parent.ProxyLabelIfNeeded(target);
var caseStatement = _F.SwitchSection(i, _F.Goto(parentProxy));
cases.Add(caseStatement);
}
}
if (frame.returnProxyLabel != null)
{
BoundLocal pendingValue = null;
if (frame.returnValue != null)
{
pendingValue = _F.Local(frame.returnValue);
}
SynthesizedLocal returnValue;
BoundStatement unpendReturn;
var returnLabel = parent.ProxyReturnIfNeeded(_F.CurrentMethod, pendingValue, out returnValue);
if (returnLabel == null)
{
unpendReturn = new BoundReturnStatement(_F.Syntax, pendingValue);
}
else
{
if (pendingValue == null)
{
unpendReturn = _F.Goto(returnLabel);
}
else
{
unpendReturn = _F.Block(
_F.Assignment(
_F.Local(returnValue),
pendingValue),
_F.Goto(returnLabel));
}
}
var caseStatement = _F.SwitchSection(i, unpendReturn);
cases.Add(caseStatement);
}
return(_F.Switch(_F.Local(pendingBranchVar), cases.ToImmutableAndFree()));
}
internal static BoundBlock ConstructFieldLikeEventAccessorBody_Regular(
SourceEventSymbol eventSymbol,
bool isAddMethod,
CSharpCompilation compilation,
BindingDiagnosticBag diagnostics
)
{
CSharpSyntaxNode syntax = eventSymbol.CSharpSyntaxNode;
TypeSymbol delegateType = eventSymbol.Type;
MethodSymbol accessor = isAddMethod ? eventSymbol.AddMethod : eventSymbol.RemoveMethod;
ParameterSymbol thisParameter = accessor.ThisParameter;
TypeSymbol boolType = compilation.GetSpecialType(SpecialType.System_Boolean);
SpecialMember updateMethodId = isAddMethod
? SpecialMember.System_Delegate__Combine
: SpecialMember.System_Delegate__Remove;
MethodSymbol updateMethod = (MethodSymbol)compilation.GetSpecialTypeMember(
updateMethodId
);
BoundStatement @return = new BoundReturnStatement(
syntax,
refKind: RefKind.None,
expressionOpt: null
)
{
WasCompilerGenerated = true
};
if (updateMethod == null)
{
MemberDescriptor memberDescriptor = SpecialMembers.GetDescriptor(updateMethodId);
diagnostics.Add(
new CSDiagnostic(
new CSDiagnosticInfo(
ErrorCode.ERR_MissingPredefinedMember,
memberDescriptor.DeclaringTypeMetadataName,
memberDescriptor.Name
),
syntax.Location
)
);
return(BoundBlock.SynthesizedNoLocals(syntax, @return));
}
Binder.ReportUseSite(updateMethod, diagnostics, syntax);
BoundThisReference fieldReceiver = eventSymbol.IsStatic
? null
: new BoundThisReference(syntax, thisParameter.Type)
{
WasCompilerGenerated = true
};
BoundFieldAccess boundBackingField = new BoundFieldAccess(
syntax,
receiver: fieldReceiver,
fieldSymbol: eventSymbol.AssociatedField,
constantValueOpt: null
)
{
WasCompilerGenerated = true
};
BoundParameter boundParameter = new BoundParameter(
syntax,
parameterSymbol: accessor.Parameters[0]
)
{
WasCompilerGenerated = true
};
BoundExpression delegateUpdate;
MethodSymbol compareExchangeMethod = (MethodSymbol)compilation.GetWellKnownTypeMember(
WellKnownMember.System_Threading_Interlocked__CompareExchange_T
);
if ((object)compareExchangeMethod == null)
{
// (DelegateType)Delegate.Combine(_event, value)
delegateUpdate = BoundConversion.SynthesizedNonUserDefined(
syntax,
operand: BoundCall.Synthesized(
syntax,
receiverOpt: null,
method: updateMethod,
arguments: ImmutableArray.Create <BoundExpression>(
boundBackingField,
boundParameter
)
),
conversion: Conversion.ExplicitReference,
type: delegateType
);
// _event = (DelegateType)Delegate.Combine(_event, value);
BoundStatement eventUpdate = new BoundExpressionStatement(
syntax,
expression: new BoundAssignmentOperator(
syntax,
left: boundBackingField,
right: delegateUpdate,
type: delegateType
)
{
WasCompilerGenerated = true
}
)
{
WasCompilerGenerated = true
};
return(BoundBlock.SynthesizedNoLocals(
syntax,
statements: ImmutableArray.Create <BoundStatement>(eventUpdate, @return)
));
}
compareExchangeMethod = compareExchangeMethod.Construct(
ImmutableArray.Create <TypeSymbol>(delegateType)
);
Binder.ReportUseSite(compareExchangeMethod, diagnostics, syntax);
GeneratedLabelSymbol loopLabel = new GeneratedLabelSymbol("loop");
const int numTemps = 3;
LocalSymbol[] tmps = new LocalSymbol[numTemps];
BoundLocal[] boundTmps = new BoundLocal[numTemps];
for (int i = 0; i < numTemps; i++)
{
tmps[i] = new SynthesizedLocal(
accessor,
TypeWithAnnotations.Create(delegateType),
SynthesizedLocalKind.LoweringTemp
);
boundTmps[i] = new BoundLocal(syntax, tmps[i], null, delegateType)
{
WasCompilerGenerated = true
};
}
// tmp0 = _event;
BoundStatement tmp0Init = new BoundExpressionStatement(
syntax,
expression: new BoundAssignmentOperator(
syntax,
left: boundTmps[0],
right: boundBackingField,
type: delegateType
)
{
WasCompilerGenerated = true
}
)
{
WasCompilerGenerated = true
};
// LOOP:
BoundStatement loopStart = new BoundLabelStatement(syntax, label: loopLabel)
{
WasCompilerGenerated = true
};
// tmp1 = tmp0;
BoundStatement tmp1Update = new BoundExpressionStatement(
syntax,
expression: new BoundAssignmentOperator(
syntax,
left: boundTmps[1],
right: boundTmps[0],
type: delegateType
)
{
WasCompilerGenerated = true
}
)
{
WasCompilerGenerated = true
};
// (DelegateType)Delegate.Combine(tmp1, value)
delegateUpdate = BoundConversion.SynthesizedNonUserDefined(
syntax,
operand: BoundCall.Synthesized(
syntax,
receiverOpt: null,
method: updateMethod,
arguments: ImmutableArray.Create <BoundExpression>(boundTmps[1], boundParameter)
),
conversion: Conversion.ExplicitReference,
type: delegateType
);
// tmp2 = (DelegateType)Delegate.Combine(tmp1, value);
BoundStatement tmp2Update = new BoundExpressionStatement(
syntax,
expression: new BoundAssignmentOperator(
syntax,
left: boundTmps[2],
right: delegateUpdate,
type: delegateType
)
{
WasCompilerGenerated = true
}
)
{
WasCompilerGenerated = true
};
// Interlocked.CompareExchange<DelegateType>(ref _event, tmp2, tmp1)
BoundExpression compareExchange = BoundCall.Synthesized(
syntax,
receiverOpt: null,
method: compareExchangeMethod,
arguments: ImmutableArray.Create <BoundExpression>(
boundBackingField,
boundTmps[2],
boundTmps[1]
)
);
// tmp0 = Interlocked.CompareExchange<DelegateType>(ref _event, tmp2, tmp1);
BoundStatement tmp0Update = new BoundExpressionStatement(
syntax,
expression: new BoundAssignmentOperator(
syntax,
left: boundTmps[0],
right: compareExchange,
type: delegateType
)
{
WasCompilerGenerated = true
}
)
{
WasCompilerGenerated = true
};
// tmp0 == tmp1 // i.e. exit when they are equal, jump to start otherwise
BoundExpression loopExitCondition = new BoundBinaryOperator(
syntax,
operatorKind: BinaryOperatorKind.ObjectEqual,
left: boundTmps[0],
right: boundTmps[1],
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: boolType
)
{
WasCompilerGenerated = true
};
// branchfalse (tmp0 == tmp1) LOOP
BoundStatement loopEnd = new BoundConditionalGoto(
syntax,
condition: loopExitCondition,
jumpIfTrue: false,
label: loopLabel
)
{
WasCompilerGenerated = true
};
return(new BoundBlock(
syntax,
locals: tmps.AsImmutable(),
statements: ImmutableArray.Create <BoundStatement>(
tmp0Init,
loopStart,
tmp1Update,
tmp2Update,
tmp0Update,
loopEnd,
@return
)
)
{
WasCompilerGenerated = true
});
}
private DecisionTree AddByValue(DecisionTree.ByType byType, BoundConstantPattern value, DecisionMaker makeDecision)
{
if (byType.Default != null)
{
try
{
return(AddByValue(byType.Default, value, makeDecision));
}
finally
{
if (byType.Default.MatchIsComplete)
{
// This code may be unreachable due to https://github.com/dotnet/roslyn/issues/16878
byType.MatchIsComplete = true;
}
}
}
if (value.ConstantValue == ConstantValue.Null)
{
// This should not occur, as the caller will have invoked AddByNull instead.
throw ExceptionUtilities.Unreachable;
}
if ((object)value.Value.Type == null)
{
return(null);
}
foreach (var kvp in byType.TypeAndDecision)
{
var matchedType = kvp.Key;
var decision = kvp.Value;
// See if the test is already subsumed
switch (ExpressionOfTypeMatchesPatternType(value.Value.Type, matchedType, ref _useSiteDiagnostics))
{
case true:
if (decision.MatchIsComplete)
{
return(null);
}
continue;
case false:
case null:
continue;
}
}
DecisionTree forType = null;
// This new type test should logically be last. However it might be the same type as the one that is already
// last. In that case we can produce better code by piggy-backing our new case on to the last decision.
// Also, the last one might be a non-overlapping type, in which case we can piggy-back onto the second-last
// type test.
for (int i = byType.TypeAndDecision.Count - 1; i >= 0; i--)
{
var kvp = byType.TypeAndDecision[i];
var matchedType = kvp.Key;
var decision = kvp.Value;
if (matchedType.TupleUnderlyingTypeOrSelf() == value.Value.Type.TupleUnderlyingTypeOrSelf())
{
forType = decision;
break;
}
else if (ExpressionOfTypeMatchesPatternType(value.Value.Type, matchedType, ref _useSiteDiagnostics) != false)
{
// because there is overlap, we cannot reuse some earlier entry
break;
}
}
// if we did not piggy-back, then create a new decision tree node for the type.
if (forType == null)
{
var type = value.Value.Type;
var localSymbol = new SynthesizedLocal(_enclosingSymbol as MethodSymbol, type, SynthesizedLocalKind.PatternMatching, Syntax, false, RefKind.None);
var narrowedExpression = new BoundLocal(Syntax, localSymbol, null, type);
forType = new DecisionTree.ByValue(narrowedExpression, value.Value.Type.TupleUnderlyingTypeOrSelf(), localSymbol);
byType.TypeAndDecision.Add(new KeyValuePair <TypeSymbol, DecisionTree>(value.Value.Type, forType));
}
return(AddByValue(forType, value, makeDecision));
}
private BoundExpression HoistRefInitialization(
SynthesizedLocal local,
BoundAssignmentOperator node
)
{
Debug.Assert(local.SynthesizedKind == SynthesizedLocalKind.Spill);
Debug.Assert(local.SyntaxOpt != null);
Debug.Assert(this.OriginalMethod.IsAsync);
var right = (BoundExpression)Visit(node.Right);
var sideEffects = ArrayBuilder <BoundExpression> .GetInstance();
bool needsSacrificialEvaluation = false;
var hoistedFields = ArrayBuilder <StateMachineFieldSymbol> .GetInstance();
AwaitExpressionSyntax awaitSyntaxOpt;
int syntaxOffset;
if (F.Compilation.Options.OptimizationLevel == OptimizationLevel.Debug)
{
awaitSyntaxOpt = (AwaitExpressionSyntax)local.GetDeclaratorSyntax();
syntaxOffset = OriginalMethod.CalculateLocalSyntaxOffset(
LambdaUtilities.GetDeclaratorPosition(awaitSyntaxOpt),
awaitSyntaxOpt.SyntaxTree
);
}
else
{
// These are only used to calculate debug id for ref-spilled variables,
// no need to do so in release build.
awaitSyntaxOpt = null;
syntaxOffset = -1;
}
var replacement = HoistExpression(
right,
awaitSyntaxOpt,
syntaxOffset,
local.RefKind,
sideEffects,
hoistedFields,
ref needsSacrificialEvaluation
);
proxies.Add(
local,
new CapturedToExpressionSymbolReplacement(
replacement,
hoistedFields.ToImmutableAndFree(),
isReusable: true
)
);
if (needsSacrificialEvaluation)
{
var type = TypeMap.SubstituteType(local.Type).Type;
var sacrificialTemp = F.SynthesizedLocal(type, refKind: RefKind.Ref);
Debug.Assert(
TypeSymbol.Equals(type, replacement.Type, TypeCompareKind.ConsiderEverything2)
);
return(F.Sequence(
ImmutableArray.Create(sacrificialTemp),
sideEffects.ToImmutableAndFree(),
F.AssignmentExpression(F.Local(sacrificialTemp), replacement, isRef: true)
));
}
if (sideEffects.Count == 0)
{
sideEffects.Free();
return(null);
}
var last = sideEffects.Last();
sideEffects.RemoveLast();
return(F.Sequence(
ImmutableArray <LocalSymbol> .Empty,
sideEffects.ToImmutableAndFree(),
last
));
}
/// <summary>
/// Generate a thread-safe accessor for a regular field-like event.
///
/// DelegateType tmp0 = _event; //backing field
/// DelegateType tmp1;
/// DelegateType tmp2;
/// do {
/// tmp1 = tmp0;
/// tmp2 = (DelegateType)Delegate.Combine(tmp1, value); //Remove for -=
/// tmp0 = Interlocked.CompareExchange<DelegateType>(ref _event, tmp2, tmp1);
/// } while ((object)tmp0 != (object)tmp1);
/// </summary>
internal static BoundBlock ConstructFieldLikeEventAccessorBody_Regular(SourceEventSymbol eventSymbol, bool isAddMethod, CSharpCompilation compilation, DiagnosticBag diagnostics)
{
CSharpSyntaxNode syntax = eventSymbol.CSharpSyntaxNode;
TypeSymbol delegateType = eventSymbol.Type;
MethodSymbol accessor = isAddMethod ? eventSymbol.AddMethod : eventSymbol.RemoveMethod;
ParameterSymbol thisParameter = accessor.ThisParameter;
TypeSymbol boolType = compilation.GetSpecialType(SpecialType.System_Boolean);
MethodSymbol updateMethod = (MethodSymbol)compilation.GetSpecialTypeMember(isAddMethod ? SpecialMember.System_Delegate__Combine : SpecialMember.System_Delegate__Remove);
MethodSymbol compareExchangeMethod = GetConstructedCompareExchangeMethod(delegateType, compilation, accessor.Locations[0], diagnostics);
if ((object)compareExchangeMethod == null)
{
return(new BoundBlock(syntax,
locals: ImmutableArray <LocalSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(
new BoundReturnStatement(syntax,
expressionOpt: null)
{
WasCompilerGenerated = true
}))
{
WasCompilerGenerated = true
});
}
GeneratedLabelSymbol loopLabel = new GeneratedLabelSymbol("loop");
const int numTemps = 3;
LocalSymbol[] tmps = new LocalSymbol[numTemps];
BoundLocal[] boundTmps = new BoundLocal[numTemps];
for (int i = 0; i < numTemps; i++)
{
tmps[i] = new SynthesizedLocal(accessor, delegateType, SynthesizedLocalKind.LoweringTemp);
boundTmps[i] = new BoundLocal(syntax, tmps[i], null, delegateType);
}
BoundThisReference fieldReceiver = eventSymbol.IsStatic ?
null :
new BoundThisReference(syntax, thisParameter.Type)
{
WasCompilerGenerated = true
};
BoundFieldAccess boundBackingField = new BoundFieldAccess(syntax,
receiver: fieldReceiver,
fieldSymbol: eventSymbol.AssociatedField,
constantValueOpt: null)
{
WasCompilerGenerated = true
};
BoundParameter boundParameter = new BoundParameter(syntax,
parameterSymbol: accessor.Parameters[0])
{
WasCompilerGenerated = true
};
// tmp0 = _event;
BoundStatement tmp0Init = new BoundExpressionStatement(syntax,
expression: new BoundAssignmentOperator(syntax,
left: boundTmps[0],
right: boundBackingField,
type: delegateType)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
// LOOP:
BoundStatement loopStart = new BoundLabelStatement(syntax,
label: loopLabel)
{
WasCompilerGenerated = true
};
// tmp1 = tmp0;
BoundStatement tmp1Update = new BoundExpressionStatement(syntax,
expression: new BoundAssignmentOperator(syntax,
left: boundTmps[1],
right: boundTmps[0],
type: delegateType)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
// (DelegateType)Delegate.Combine(tmp1, value)
BoundExpression delegateUpdate = BoundConversion.SynthesizedNonUserDefined(syntax,
operand: BoundCall.Synthesized(syntax,
receiverOpt: null,
method: updateMethod,
arguments: ImmutableArray.Create <BoundExpression>(boundTmps[1], boundParameter)),
kind: ConversionKind.ExplicitReference,
type: delegateType);
// tmp2 = (DelegateType)Delegate.Combine(tmp1, value);
BoundStatement tmp2Update = new BoundExpressionStatement(syntax,
expression: new BoundAssignmentOperator(syntax,
left: boundTmps[2],
right: delegateUpdate,
type: delegateType)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
// Interlocked.CompareExchange<DelegateType>(ref _event, tmp2, tmp1)
BoundExpression compareExchange = BoundCall.Synthesized(syntax,
receiverOpt: null,
method: compareExchangeMethod,
arguments: ImmutableArray.Create <BoundExpression>(boundBackingField, boundTmps[2], boundTmps[1]));
// tmp0 = Interlocked.CompareExchange<DelegateType>(ref _event, tmp2, tmp1);
BoundStatement tmp0Update = new BoundExpressionStatement(syntax,
expression: new BoundAssignmentOperator(syntax,
left: boundTmps[0],
right: compareExchange,
type: delegateType)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
// tmp0 == tmp1 // i.e. exit when they are equal, jump to start otherwise
BoundExpression loopExitCondition = new BoundBinaryOperator(syntax,
operatorKind: BinaryOperatorKind.ObjectEqual,
left: boundTmps[0],
right: boundTmps[1],
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: boolType)
{
WasCompilerGenerated = true
};
// branchfalse (tmp0 == tmp1) LOOP
BoundStatement loopEnd = new BoundConditionalGoto(syntax,
condition: loopExitCondition,
jumpIfTrue: false,
label: loopLabel)
{
WasCompilerGenerated = true
};
BoundStatement @return = new BoundReturnStatement(syntax,
expressionOpt: null)
{
WasCompilerGenerated = true
};
return(new BoundBlock(syntax,
locals: tmps.AsImmutable(),
statements: ImmutableArray.Create <BoundStatement>(
tmp0Init,
loopStart,
tmp1Update,
tmp2Update,
tmp0Update,
loopEnd,
@return))
{
WasCompilerGenerated = true
});
}
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(
tryStatementSyntax.IsKind(SyntaxKind.TryStatement) ||
tryStatementSyntax.IsKind(SyntaxKind.UsingStatement) ||
tryStatementSyntax.IsKind(SyntaxKind.ForEachStatement) ||
tryStatementSyntax.IsKind(SyntaxKind.ForEachVariableStatement));
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, TypeSymbolWithAnnotations.Create(exceptionType), SynthesizedLocalKind.TryAwaitPendingException, tryStatementSyntax);
var finallyLabel = _F.GenerateLabel("finallyLabel");
var pendingBranchVar = new SynthesizedLocal(_F.CurrentFunction, TypeSymbolWithAnnotations.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.TypeSymbol)));
locals.Add(pendingBranchVar);
statements.Add(_F.Assignment(_F.Local(pendingBranchVar), _F.Default(pendingBranchVar.Type.TypeSymbol)));
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);
}