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();
SyntaxNode awaitSyntaxOpt;
int syntaxOffset;
if (F.Compilation.Options.OptimizationLevel == OptimizationLevel.Debug)
{
awaitSyntaxOpt = local.GetDeclaratorSyntax();
Debug.Assert(awaitSyntaxOpt.IsKind(SyntaxKind.AwaitExpression) || awaitSyntaxOpt.IsKind(SyntaxKind.SwitchExpression));
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));
}
internal DebugId GetClosureId(SyntaxNode syntax, ArrayBuilder <ClosureDebugInfo> closureDebugInfo)
{
Debug.Assert(syntax != null);
DebugId closureId;
DebugId previousClosureId;
if (_slotAllocatorOpt != null && _slotAllocatorOpt.TryGetPreviousClosure(syntax, out previousClosureId))
{
closureId = previousClosureId;
}
else
{
closureId = new DebugId(closureDebugInfo.Count, _compilationState.ModuleBuilderOpt.CurrentGenerationOrdinal);
}
int syntaxOffset = _topLevelMethod.CalculateLocalSyntaxOffset(LambdaUtilities.GetDeclaratorPosition(syntax), syntax.SyntaxTree);
closureDebugInfo.Add(new ClosureDebugInfo(syntaxOffset, closureId));
return(closureId);
}
private void CreateNonReusableLocalProxies(
IEnumerable <Symbol> variablesToHoist,
out IReadOnlyDictionary <Symbol, CapturedSymbolReplacement> proxies,
out int nextFreeHoistedLocalSlot)
{
var proxiesBuilder = new Dictionary <Symbol, CapturedSymbolReplacement>();
var typeMap = stateMachineType.TypeMap;
bool isDebugBuild = F.Compilation.Options.OptimizationLevel == OptimizationLevel.Debug;
bool mapToPreviousFields = isDebugBuild && slotAllocatorOpt != null;
nextFreeHoistedLocalSlot = mapToPreviousFields ? slotAllocatorOpt.PreviousHoistedLocalSlotCount : 0;
foreach (var variable in variablesToHoist)
{
Debug.Assert(variable.Kind == SymbolKind.Local || variable.Kind == SymbolKind.Parameter);
if (variable.Kind == SymbolKind.Local)
{
var local = (LocalSymbol)variable;
var synthesizedKind = local.SynthesizedKind;
if (!synthesizedKind.MustSurviveStateMachineSuspension())
{
continue;
}
// no need to hoist constants
if (local.IsConst)
{
continue;
}
if (local.RefKind != RefKind.None)
{
// we'll create proxies for these variables later:
Debug.Assert(synthesizedKind == SynthesizedLocalKind.Spill);
continue;
}
Debug.Assert(local.RefKind == RefKind.None);
StateMachineFieldSymbol field = null;
if (ShouldPreallocateNonReusableProxy(local))
{
// variable needs to be hoisted
var fieldType = typeMap.SubstituteType(local.Type).Type;
LocalDebugId id;
int slotIndex = -1;
if (isDebugBuild)
{
// Calculate local debug id.
//
// EnC: When emitting the baseline (gen 0) the id is stored in a custom debug information attached to the kickoff method.
// When emitting a delta the id is only used to map to the existing field in the previous generation.
SyntaxNode declaratorSyntax = local.GetDeclaratorSyntax();
int syntaxOffset = method.CalculateLocalSyntaxOffset(LambdaUtilities.GetDeclaratorPosition(declaratorSyntax), declaratorSyntax.SyntaxTree);
int ordinal = synthesizedLocalOrdinals.AssignLocalOrdinal(synthesizedKind, syntaxOffset);
id = new LocalDebugId(syntaxOffset, ordinal);
// map local id to the previous id, if available:
int previousSlotIndex;
if (mapToPreviousFields && slotAllocatorOpt.TryGetPreviousHoistedLocalSlotIndex(
declaratorSyntax,
F.ModuleBuilderOpt.Translate(fieldType, declaratorSyntax, diagnostics),
synthesizedKind,
id,
diagnostics,
out previousSlotIndex))
{
slotIndex = previousSlotIndex;
}
}
else
{
id = LocalDebugId.None;
}
if (slotIndex == -1)
{
slotIndex = nextFreeHoistedLocalSlot++;
}
string fieldName = GeneratedNames.MakeHoistedLocalFieldName(synthesizedKind, slotIndex, local.Name);
field = F.StateMachineField(fieldType, fieldName, new LocalSlotDebugInfo(synthesizedKind, id), slotIndex);
}
if (field != null)
{
proxiesBuilder.Add(local, new CapturedToStateMachineFieldReplacement(field, isReusable: false));
}
}
else
{
var parameter = (ParameterSymbol)variable;
if (parameter.IsThis)
{
var containingType = method.ContainingType;
var proxyField = F.StateMachineField(containingType, GeneratedNames.ThisProxyFieldName(), isPublic: true, isThis: true);
proxiesBuilder.Add(parameter, new CapturedToStateMachineFieldReplacement(proxyField, isReusable: false));
if (PreserveInitialParameterValuesAndThreadId)
{
var initialThis = containingType.IsStructType() ?
F.StateMachineField(containingType, GeneratedNames.StateMachineThisParameterProxyName(), isPublic: true, isThis: true) : proxyField;
initialParameters.Add(parameter, new CapturedToStateMachineFieldReplacement(initialThis, isReusable: false));
}
}
else
{
// The field needs to be public iff it is initialized directly from the kickoff method
// (i.e. not for IEnumerable which loads the values from parameter proxies).
var proxyField = F.StateMachineField(typeMap.SubstituteType(parameter.Type).Type, parameter.Name, isPublic: !PreserveInitialParameterValuesAndThreadId);
proxiesBuilder.Add(parameter, new CapturedToStateMachineFieldReplacement(proxyField, isReusable: false));
if (PreserveInitialParameterValuesAndThreadId)
{
var field = F.StateMachineField(typeMap.SubstituteType(parameter.Type).Type, GeneratedNames.StateMachineParameterProxyFieldName(parameter.Name), isPublic: true);
initialParameters.Add(parameter, new CapturedToStateMachineFieldReplacement(field, isReusable: false));
}
}
}
}
proxies = proxiesBuilder;
}