internal VariableSlotAllocator?TryCreateVariableSlotAllocator(EmitBaseline baseline, Compilation compilation, IMethodSymbolInternal method, IMethodSymbolInternal topLevelMethod, DiagnosticBag diagnostics)
{
// Top-level methods are always included in the semantic edit list. Lambda methods are not.
if (!mappedMethods.TryGetValue(topLevelMethod, out var mappedMethod))
{
return(null);
}
// TODO (bug https://github.com/dotnet/roslyn/issues/2504):
// Handle cases when the previous method doesn't exist.
if (!TryGetMethodHandle(baseline, (Cci.IMethodDefinition)method.GetCciAdapter(), out var previousHandle))
{
// Unrecognized method. Must have been added in the current compilation.
return(null);
}
ImmutableArray <EncLocalInfo> previousLocals;
IReadOnlyDictionary <EncHoistedLocalInfo, int>? hoistedLocalMap = null;
IReadOnlyDictionary <Cci.ITypeReference, int>? awaiterMap = null;
IReadOnlyDictionary <int, KeyValuePair <DebugId, int> >?lambdaMap = null;
IReadOnlyDictionary <int, DebugId>?closureMap = null;
IReadOnlyDictionary <int, int>? stateMachineStateMap = null;
int?firstUnusedIncreasingStateMachineState = null;
int?firstUnusedDecreasingStateMachineState = null;
int hoistedLocalSlotCount = 0;
int awaiterSlotCount = 0;
string? stateMachineTypeName = null;
SymbolMatcher symbolMap;
int methodIndex = MetadataTokens.GetRowNumber(previousHandle);
DebugId methodId;
// Check if method has changed previously. If so, we already have a map.
if (baseline.AddedOrChangedMethods.TryGetValue(methodIndex, out var addedOrChangedMethod))
{
methodId = addedOrChangedMethod.MethodId;
MakeLambdaAndClosureMaps(addedOrChangedMethod.LambdaDebugInfo, addedOrChangedMethod.ClosureDebugInfo, out lambdaMap, out closureMap);
MakeStateMachineStateMap(addedOrChangedMethod.StateMachineStates.States, out stateMachineStateMap);
firstUnusedIncreasingStateMachineState = addedOrChangedMethod.StateMachineStates.FirstUnusedIncreasingStateMachineState;
firstUnusedDecreasingStateMachineState = addedOrChangedMethod.StateMachineStates.FirstUnusedDecreasingStateMachineState;
if (addedOrChangedMethod.StateMachineTypeName != null)
{
// method is async/iterator kickoff method
GetStateMachineFieldMapFromPreviousCompilation(
addedOrChangedMethod.StateMachineHoistedLocalSlotsOpt,
addedOrChangedMethod.StateMachineAwaiterSlotsOpt,
out hoistedLocalMap,
out awaiterMap);
hoistedLocalSlotCount = addedOrChangedMethod.StateMachineHoistedLocalSlotsOpt.Length;
awaiterSlotCount = addedOrChangedMethod.StateMachineAwaiterSlotsOpt.Length;
// Kickoff method has no interesting locals on its own.
// We use the EnC method debug information for hoisted locals.
previousLocals = ImmutableArray <EncLocalInfo> .Empty;
stateMachineTypeName = addedOrChangedMethod.StateMachineTypeName;
}
else
{
previousLocals = addedOrChangedMethod.Locals;
}
// All types that AddedOrChangedMethodInfo refers to have been mapped to the previous generation.
// Therefore we don't need to fall back to metadata if we don't find the type reference, like we do in DefinitionMap.MapReference.
symbolMap = MapToPreviousSymbolMatcher;
}
else
{
// Method has not changed since initial generation. Generate a map
// using the local names provided with the initial metadata.
EditAndContinueMethodDebugInformation debugInfo;
StandaloneSignatureHandle localSignature;
try
{
debugInfo = baseline.DebugInformationProvider(previousHandle);
localSignature = baseline.LocalSignatureProvider(previousHandle);
}
catch (Exception e) when(e is InvalidDataException || e is IOException)
{
diagnostics.Add(MessageProvider.CreateDiagnostic(
MessageProvider.ERR_InvalidDebugInfo,
method.Locations.First(),
method,
MetadataTokens.GetToken(previousHandle),
method.ContainingAssembly
));
return(null);
}
methodId = new DebugId(debugInfo.MethodOrdinal, 0);
if (!debugInfo.Lambdas.IsDefaultOrEmpty)
{
MakeLambdaAndClosureMaps(debugInfo.Lambdas, debugInfo.Closures, out lambdaMap, out closureMap);
}
MakeStateMachineStateMap(debugInfo.StateMachineStates, out stateMachineStateMap);
if (!debugInfo.StateMachineStates.IsDefaultOrEmpty)
{
firstUnusedIncreasingStateMachineState = debugInfo.StateMachineStates.Max(s => s.StateNumber) + 1;
firstUnusedDecreasingStateMachineState = debugInfo.StateMachineStates.Min(s => s.StateNumber) - 1;
}
ITypeSymbolInternal?stateMachineType = TryGetStateMachineType(previousHandle);
if (stateMachineType != null)
{
// method is async/iterator kickoff method
var localSlotDebugInfo = debugInfo.LocalSlots.NullToEmpty();
GetStateMachineFieldMapFromMetadata(stateMachineType, localSlotDebugInfo, out hoistedLocalMap, out awaiterMap, out awaiterSlotCount);
hoistedLocalSlotCount = localSlotDebugInfo.Length;
// Kickoff method has no interesting locals on its own.
// We use the EnC method debug information for hoisted locals.
previousLocals = ImmutableArray <EncLocalInfo> .Empty;
stateMachineTypeName = stateMachineType.Name;
}
else
{
// If the current method is async/iterator then either the previous method wasn't declared as async/iterator and it's updated to be one,
// or it was but is not marked by the corresponding state machine attribute because it was missing in the compilation.
// In the later case we need to report an error since we don't known how to map to the previous state machine.
// The IDE already checked that the attribute type is present in the base compilation, but didn't validate that it is well-formed.
// We don't have the base compilation to directly query for the attribute, only the source compilation.
// But since constructor signatures can't be updated during EnC we can just check the current compilation.
if (method.IsAsync)
{
if (compilation.CommonGetWellKnownTypeMember(WellKnownMember.System_Runtime_CompilerServices_AsyncStateMachineAttribute__ctor) == null)
{
ReportMissingStateMachineAttribute(diagnostics, method, AttributeDescription.AsyncStateMachineAttribute.FullName);
return(null);
}
}
else if (method.IsIterator)
{
if (compilation.CommonGetWellKnownTypeMember(WellKnownMember.System_Runtime_CompilerServices_IteratorStateMachineAttribute__ctor) == null)
{
ReportMissingStateMachineAttribute(diagnostics, method, AttributeDescription.IteratorStateMachineAttribute.FullName);
return(null);
}
}
try
{
previousLocals = localSignature.IsNil ? ImmutableArray <EncLocalInfo> .Empty :
GetLocalSlotMapFromMetadata(localSignature, debugInfo);
}
catch (Exception e) when(e is UnsupportedSignatureContent || e is BadImageFormatException || e is IOException)
{
diagnostics.Add(MessageProvider.CreateDiagnostic(
MessageProvider.ERR_InvalidDebugInfo,
method.Locations.First(),
method,
MetadataTokens.GetToken(localSignature),
method.ContainingAssembly
));
return(null);
}
}
symbolMap = MapToMetadataSymbolMatcher;
}
return(new EncVariableSlotAllocator(
symbolMap,
mappedMethod.SyntaxMap,
mappedMethod.PreviousMethod,
methodId,
previousLocals,
lambdaMap,
closureMap,
stateMachineTypeName,
hoistedLocalSlotCount,
hoistedLocalMap,
awaiterSlotCount,
awaiterMap,
stateMachineStateMap,
firstUnusedIncreasingStateMachineState,
firstUnusedDecreasingStateMachineState,
GetLambdaSyntaxFacts()));
}