/// <summary>
/// Rewrite an async method into a state machine type.
/// </summary>
internal static BoundStatement Rewrite(
BoundStatement body,
MethodSymbol method,
int methodOrdinal,
VariableSlotAllocator slotAllocatorOpt,
TypeCompilationState compilationState,
DiagnosticBag diagnostics,
out AsyncStateMachine stateMachineType)
{
if (!method.IsAsync)
{
stateMachineType = null;
return body;
}
// The CLR doesn't support adding fields to structs, so in order to enable EnC in an async method we need to generate a class.
var typeKind = compilationState.Compilation.Options.EnableEditAndContinue ? TypeKind.Class : TypeKind.Struct;
var bodyWithAwaitLifted = AwaitExpressionSpiller.Rewrite(body, method, compilationState, diagnostics);
stateMachineType = new AsyncStateMachine(slotAllocatorOpt, compilationState, method, methodOrdinal, typeKind);
compilationState.ModuleBuilderOpt.CompilationState.SetStateMachineType(method, stateMachineType);
var rewriter = new AsyncRewriter(bodyWithAwaitLifted, method, methodOrdinal, stateMachineType, slotAllocatorOpt, compilationState, diagnostics);
if (!rewriter.VerifyPresenceOfRequiredAPIs())
{
return body;
}
return rewriter.Rewrite();
}
internal AsyncMethodToStateMachineRewriter(
MethodSymbol method,
int methodOrdinal,
AsyncMethodBuilderMemberCollection asyncMethodBuilderMemberCollection,
SyntheticBoundNodeFactory F,
FieldSymbol state,
FieldSymbol builder,
IReadOnlySet<Symbol> hoistedVariables,
IReadOnlyDictionary<Symbol, CapturedSymbolReplacement> nonReusableLocalProxies,
SynthesizedLocalOrdinalsDispenser synthesizedLocalOrdinals,
VariableSlotAllocator slotAllocatorOpt,
int nextFreeHoistedLocalSlot,
DiagnosticBag diagnostics)
: base(F, method, state, hoistedVariables, nonReusableLocalProxies, synthesizedLocalOrdinals, slotAllocatorOpt, nextFreeHoistedLocalSlot, diagnostics, useFinalizerBookkeeping: false)
{
_method = method;
_asyncMethodBuilderMemberCollection = asyncMethodBuilderMemberCollection;
_asyncMethodBuilderField = builder;
_exprReturnLabel = F.GenerateLabel("exprReturn");
_exitLabel = F.GenerateLabel("exitLabel");
_exprRetValue = method.IsGenericTaskReturningAsync(F.Compilation)
? F.SynthesizedLocal(asyncMethodBuilderMemberCollection.ResultType, syntax: F.Syntax, kind: SynthesizedLocalKind.AsyncMethodReturnValue)
: null;
_dynamicFactory = new LoweredDynamicOperationFactory(F, methodOrdinal);
_awaiterFields = new Dictionary<TypeSymbol, FieldSymbol>(TypeSymbol.EqualsIgnoringDynamicComparer);
_nextAwaiterId = slotAllocatorOpt?.PreviousAwaiterSlotCount ?? 0;
}
private static string MakeName(VariableSlotAllocator slotAllocatorOpt, SyntaxNode scopeSyntaxOpt, MethodDebugId methodId, int closureOrdinal)
{
if (scopeSyntaxOpt == null)
{
// Display class is shared among static non-generic lambdas accross generations, method ordinal is -1 in that case.
// A new display class of a static generic lambda is created for each method and each generation.
return GeneratedNames.MakeStaticLambdaDisplayClassName(methodId.Ordinal, methodId.Generation);
}
int previousClosureOrdinal;
if (slotAllocatorOpt != null && slotAllocatorOpt.TryGetPreviousClosure(scopeSyntaxOpt, out previousClosureOrdinal))
{
methodId = slotAllocatorOpt.PreviousMethodId;
closureOrdinal = previousClosureOrdinal;
}
// If we haven't found existing closure in the previous generation, use the current generation method ordinal.
// That is, don't try to reuse previous generation method ordinal as that might create name conflict.
// E.g.
// Gen0 Gen1
// F() { new closure } // ordinal 0
// G() { } // ordinal 0 G() { new closure } // ordinal 1
//
// In the example above G is updated and F is added.
// G's ordinal in Gen0 is 0. If we used that ordinal for updated G's new closure it would conflict with F's ordinal.
Debug.Assert(methodId.Ordinal >= 0);
return GeneratedNames.MakeLambdaDisplayClassName(methodId.Ordinal, methodId.Generation, closureOrdinal);
}
protected StateMachineRewriter(
BoundStatement body,
MethodSymbol method,
SynthesizedContainer stateMachineType,
VariableSlotAllocator slotAllocatorOpt,
TypeCompilationState compilationState,
DiagnosticBag diagnostics)
{
Debug.Assert(body != null);
Debug.Assert(method != null);
Debug.Assert(stateMachineType != null);
Debug.Assert(compilationState != null);
Debug.Assert(diagnostics != null);
this.body = body;
this.method = method;
this.stateMachineType = stateMachineType;
this.slotAllocatorOpt = slotAllocatorOpt;
this.synthesizedLocalOrdinals = new SynthesizedLocalOrdinalsDispenser();
this.diagnostics = diagnostics;
this.F = new SyntheticBoundNodeFactory(method, body.Syntax, compilationState, diagnostics);
Debug.Assert(F.CurrentType == method.ContainingType);
Debug.Assert(F.Syntax == body.Syntax);
}
public AsyncStateMachine(VariableSlotAllocator variableAllocatorOpt, TypeCompilationState compilationState, MethodSymbol asyncMethod, int asyncMethodOrdinal, TypeKind typeKind)
: base(variableAllocatorOpt, compilationState, asyncMethod, asyncMethodOrdinal)
{
// TODO: report use-site errors on these types
_typeKind = typeKind;
_interfaces = ImmutableArray.Create(asyncMethod.DeclaringCompilation.GetWellKnownType(WellKnownType.System_Runtime_CompilerServices_IAsyncStateMachine));
_constructor = new AsyncConstructor(this);
}
protected MethodToClassRewriter(VariableSlotAllocator slotAllocatorOpt, TypeCompilationState compilationState, DiagnosticBag diagnostics)
{
Debug.Assert(compilationState != null);
Debug.Assert(diagnostics != null);
this.CompilationState = compilationState;
this.Diagnostics = diagnostics;
this.slotAllocatorOpt = slotAllocatorOpt;
}
public LocalSlotManager(VariableSlotAllocator slotAllocatorOpt)
{
_slotAllocatorOpt = slotAllocatorOpt;
// Add placeholders for pre-allocated locals.
// The actual identities are populated if/when the locals are reused.
if (slotAllocatorOpt != null)
{
_lazyAllLocals = new ArrayBuilder <Cci.ILocalDefinition>();
slotAllocatorOpt.AddPreviousLocals(_lazyAllLocals);
}
}
private AsyncRewriter(
BoundStatement body,
MethodSymbol method,
int methodOrdinal,
AsyncStateMachine stateMachineType,
VariableSlotAllocator slotAllocatorOpt,
TypeCompilationState compilationState,
DiagnosticBag diagnostics)
: base(body, method, stateMachineType, slotAllocatorOpt, compilationState, diagnostics)
{
_constructedSuccessfully = AsyncMethodBuilderMemberCollection.TryCreate(F, method, this.stateMachineType.TypeMap, out _asyncMethodBuilderMemberCollection);
_methodOrdinal = methodOrdinal;
_ignoreAccessibility = compilationState.ModuleBuilderOpt.IgnoreAccessibility;
}
internal static MethodBody GenerateMethodBody(
PEModuleBuilder moduleBuilder,
SourceRoutineSymbol routine,
int methodOrdinal,
//ImmutableArray<LambdaDebugInfo> lambdaDebugInfo,
//ImmutableArray<ClosureDebugInfo> closureDebugInfo,
//StateMachineTypeSymbol stateMachineTypeOpt,
VariableSlotAllocator variableSlotAllocatorOpt,
DiagnosticBag diagnostics,
//ImportChain importChainOpt,
bool emittingPdb)
{
return GenerateMethodBody(moduleBuilder, routine, (builder) =>
{
DiagnosticBag diagnosticsForThisMethod = DiagnosticBag.GetInstance();
var optimization = moduleBuilder.Compilation.Options.OptimizationLevel;
var codeGen = new CodeGenerator(routine, builder, moduleBuilder, diagnosticsForThisMethod, optimization, emittingPdb);
//if (diagnosticsForThisMethod.HasAnyErrors())
//{
// // we are done here. Since there were errors we should not emit anything.
// return null;
//}
// We need to save additional debugging information for MoveNext of an async state machine.
//var stateMachineMethod = method as SynthesizedStateMachineMethod;
//bool isStateMachineMoveNextMethod = stateMachineMethod != null && method.Name == WellKnownMemberNames.MoveNextMethodName;
//if (isStateMachineMoveNextMethod && stateMachineMethod.StateMachineType.KickoffMethod.IsAsync)
//{
// int asyncCatchHandlerOffset;
// ImmutableArray<int> asyncYieldPoints;
// ImmutableArray<int> asyncResumePoints;
// codeGen.Generate(out asyncCatchHandlerOffset, out asyncYieldPoints, out asyncResumePoints);
// var kickoffMethod = stateMachineMethod.StateMachineType.KickoffMethod;
// // The exception handler IL offset is used by the debugger to treat exceptions caught by the marked catch block as "user unhandled".
// // This is important for async void because async void exceptions generally result in the process being terminated,
// // but without anything useful on the call stack. Async Task methods on the other hand return exceptions as the result of the Task.
// // So it is undesirable to consider these exceptions "user unhandled" since there may well be user code that is awaiting the task.
// // This is a heuristic since it's possible that there is no user code awaiting the task.
// asyncDebugInfo = new Cci.AsyncMethodBodyDebugInfo(kickoffMethod, kickoffMethod.ReturnsVoid ? asyncCatchHandlerOffset : -1, asyncYieldPoints, asyncResumePoints);
//}
//else
{
codeGen.Generate();
}
}, variableSlotAllocatorOpt, diagnostics, emittingPdb);
}
private IteratorRewriter(
BoundStatement body,
MethodSymbol method,
bool isEnumerable,
IteratorStateMachine stateMachineType,
VariableSlotAllocator slotAllocatorOpt,
TypeCompilationState compilationState,
DiagnosticBag diagnostics)
: base(body, method, stateMachineType, slotAllocatorOpt, compilationState, diagnostics)
{
// the element type may contain method type parameters, which are now alpha-renamed into type parameters of the generated class
_elementType = stateMachineType.ElementType;
_isEnumerable = isEnumerable;
}
private int _nextFinalizeState = StateMachineStates.FinishedStateMachine - 1; // -3
internal IteratorMethodToStateMachineRewriter(
SyntheticBoundNodeFactory F,
MethodSymbol originalMethod,
FieldSymbol state,
FieldSymbol current,
IReadOnlySet<Symbol> hoistedVariables,
IReadOnlyDictionary<Symbol, CapturedSymbolReplacement> nonReusableLocalProxies,
SynthesizedLocalOrdinalsDispenser synthesizedLocalOrdinals,
VariableSlotAllocator slotAllocatorOpt,
int nextFreeHoistedLocalSlot,
DiagnosticBag diagnostics)
: base(F, originalMethod, state, hoistedVariables, nonReusableLocalProxies, synthesizedLocalOrdinals, slotAllocatorOpt, nextFreeHoistedLocalSlot, diagnostics, useFinalizerBookkeeping: false)
{
_current = current;
}
internal LambdaFrame(VariableSlotAllocator slotAllocatorOpt, MethodSymbol topLevelMethod, MethodDebugId methodId, CSharpSyntaxNode scopeSyntaxOpt, int closureOrdinal)
: base(MakeName(slotAllocatorOpt, scopeSyntaxOpt, methodId, closureOrdinal), topLevelMethod)
{
_topLevelMethod = topLevelMethod;
_constructor = new LambdaFrameConstructor(this);
this.ClosureOrdinal = closureOrdinal;
// static lambdas technically have the class scope so the scope syntax is null
if (scopeSyntaxOpt == null)
{
_staticConstructor = new SynthesizedStaticConstructor(this);
var cacheVariableName = GeneratedNames.MakeCachedFrameInstanceFieldName();
_singletonCache = new SynthesizedLambdaCacheFieldSymbol(this, this, cacheVariableName, topLevelMethod, isReadOnly: true, isStatic: true);
}
AssertIsLambdaScopeSyntax(scopeSyntaxOpt);
this.ScopeSyntaxOpt = scopeSyntaxOpt;
}
/// <summary>
/// Rewrite an iterator method into a state machine class.
/// </summary>
internal static BoundStatement Rewrite(
BoundStatement body,
MethodSymbol method,
int methodOrdinal,
VariableSlotAllocator slotAllocatorOpt,
TypeCompilationState compilationState,
DiagnosticBag diagnostics,
out IteratorStateMachine stateMachineType)
{
TypeSymbol elementType = method.IteratorElementType;
if ((object)elementType == null)
{
stateMachineType = null;
return body;
}
// Figure out what kind of iterator we are generating.
bool isEnumerable;
switch (method.ReturnType.OriginalDefinition.SpecialType)
{
case SpecialType.System_Collections_IEnumerable:
case SpecialType.System_Collections_Generic_IEnumerable_T:
isEnumerable = true;
break;
case SpecialType.System_Collections_IEnumerator:
case SpecialType.System_Collections_Generic_IEnumerator_T:
isEnumerable = false;
break;
default:
throw ExceptionUtilities.UnexpectedValue(method.ReturnType.OriginalDefinition.SpecialType);
}
stateMachineType = new IteratorStateMachine(slotAllocatorOpt, compilationState, method, methodOrdinal, isEnumerable, elementType);
compilationState.ModuleBuilderOpt.CompilationState.SetStateMachineType(method, stateMachineType);
var rewriter = new IteratorRewriter(body, method, isEnumerable, stateMachineType, slotAllocatorOpt, compilationState, diagnostics);
if (!rewriter.VerifyPresenceOfRequiredAPIs())
{
return body;
}
return rewriter.Rewrite();
}
public IteratorStateMachine(VariableSlotAllocator slotAllocatorOpt, TypeCompilationState compilationState, MethodSymbol iteratorMethod, int iteratorMethodOrdinal, bool isEnumerable, TypeSymbol elementType)
: base(slotAllocatorOpt, compilationState, iteratorMethod, iteratorMethodOrdinal)
{
this.ElementType = TypeMap.SubstituteType(elementType);
var interfaces = ArrayBuilder<NamedTypeSymbol>.GetInstance();
if (isEnumerable)
{
interfaces.Add(ContainingAssembly.GetSpecialType(SpecialType.System_Collections_Generic_IEnumerable_T).Construct(ElementType));
interfaces.Add(ContainingAssembly.GetSpecialType(SpecialType.System_Collections_IEnumerable));
}
interfaces.Add(ContainingAssembly.GetSpecialType(SpecialType.System_Collections_Generic_IEnumerator_T).Construct(ElementType));
interfaces.Add(ContainingAssembly.GetSpecialType(SpecialType.System_IDisposable));
interfaces.Add(ContainingAssembly.GetSpecialType(SpecialType.System_Collections_IEnumerator));
_interfaces = interfaces.ToImmutableAndFree();
_constructor = new IteratorConstructor(this);
}
private AsyncRewriter(
BoundStatement body,
MethodSymbol method,
int methodOrdinal,
AsyncStateMachine stateMachineType,
VariableSlotAllocator slotAllocatorOpt,
TypeCompilationState compilationState,
DiagnosticBag diagnostics)
: base(body, method, stateMachineType, slotAllocatorOpt, compilationState, diagnostics)
{
try
{
_constructedSuccessfully = AsyncMethodBuilderMemberCollection.TryCreate(F, method, this.stateMachineType.TypeMap, out _asyncMethodBuilderMemberCollection);
}
catch (SyntheticBoundNodeFactory.MissingPredefinedMember ex)
{
diagnostics.Add(ex.Diagnostic);
_constructedSuccessfully = false;
}
_methodOrdinal = methodOrdinal;
_ignoreAccessibility = compilationState.ModuleBuilderOpt.IgnoreAccessibility;
}
/// <summary>
/// Generates method body that calls another method.
/// Used for wrapping a method call into a method, e.g. an entry point.
/// </summary>
internal static MethodBody GenerateMethodBody(
PEModuleBuilder moduleBuilder,
MethodSymbol routine,
Action<ILBuilder> builder,
VariableSlotAllocator variableSlotAllocatorOpt,
DiagnosticBag diagnostics,
bool emittingPdb)
{
var compilation = moduleBuilder.Compilation;
var localSlotManager = new LocalSlotManager(variableSlotAllocatorOpt);
var optimizations = compilation.Options.OptimizationLevel;
DebugDocumentProvider debugDocumentProvider = null;
if (emittingPdb)
{
debugDocumentProvider = (path, basePath) => moduleBuilder.GetOrAddDebugDocument(path, basePath, CreateDebugDocumentForFile);
}
ILBuilder il = new ILBuilder(moduleBuilder, localSlotManager, optimizations);
try
{
Cci.AsyncMethodBodyDebugInfo asyncDebugInfo = null;
builder(il);
//
il.Realize();
//
var localVariables = il.LocalSlotManager.LocalsInOrder();
if (localVariables.Length > 0xFFFE)
{
//diagnosticsForThisMethod.Add(ErrorCode.ERR_TooManyLocals, method.Locations.First());
}
//if (diagnosticsForThisMethod.HasAnyErrors())
//{
// // we are done here. Since there were errors we should not emit anything.
// return null;
//}
//// We will only save the IL builders when running tests.
//if (moduleBuilder.SaveTestData)
//{
// moduleBuilder.SetMethodTestData(method, builder.GetSnapshot());
//}
// Only compiler-generated MoveNext methods have iterator scopes. See if this is one.
var stateMachineHoistedLocalScopes = default(ImmutableArray<Cci.StateMachineHoistedLocalScope>);
//if (isStateMachineMoveNextMethod)
//{
// stateMachineHoistedLocalScopes = builder.GetHoistedLocalScopes();
//}
var stateMachineHoistedLocalSlots = default(ImmutableArray<EncHoistedLocalInfo>);
var stateMachineAwaiterSlots = default(ImmutableArray<Cci.ITypeReference>);
//if (optimizations == OptimizationLevel.Debug && stateMachineTypeOpt != null)
//{
// Debug.Assert(method.IsAsync || method.IsIterator);
// GetStateMachineSlotDebugInfo(moduleBuilder, moduleBuilder.GetSynthesizedFields(stateMachineTypeOpt), variableSlotAllocatorOpt, diagnosticsForThisMethod, out stateMachineHoistedLocalSlots, out stateMachineAwaiterSlots);
// Debug.Assert(!diagnostics.HasAnyErrors());
//}
return new MethodBody(
il.RealizedIL,
il.MaxStack,
(Cci.IMethodDefinition)routine.PartialDefinitionPart ?? routine,
variableSlotAllocatorOpt?.MethodId ?? new DebugId(0, moduleBuilder.CurrentGenerationOrdinal),
localVariables,
il.RealizedSequencePoints,
debugDocumentProvider,
il.RealizedExceptionHandlers,
il.GetAllScopes(),
il.HasDynamicLocal,
null, // importScopeOpt,
ImmutableArray<LambdaDebugInfo>.Empty, // lambdaDebugInfo,
ImmutableArray<ClosureDebugInfo>.Empty, // closureDebugInfo,
null, //stateMachineTypeOpt?.Name,
stateMachineHoistedLocalScopes,
stateMachineHoistedLocalSlots,
stateMachineAwaiterSlots,
asyncDebugInfo);
}
finally
{
// Basic blocks contain poolable builders for IL and sequence points. Free those back
// to their pools.
il.FreeBasicBlocks();
//// Remember diagnostics.
//diagnostics.AddRange(diagnosticsForThisMethod);
//diagnosticsForThisMethod.Free();
}
}
public StateMachineTypeSymbol(VariableSlotAllocator slotAllocatorOpt, TypeCompilationState compilationState, MethodSymbol kickoffMethod, int kickoffMethodOrdinal)
: base(MakeName(slotAllocatorOpt, compilationState, kickoffMethod, kickoffMethodOrdinal), kickoffMethod)
{
Debug.Assert(kickoffMethod != null);
this.KickoffMethod = kickoffMethod;
}
private static string MakeName(VariableSlotAllocator slotAllocatorOpt, TypeCompilationState compilationState, MethodSymbol kickoffMethod, int kickoffMethodOrdinal)
{
return slotAllocatorOpt?.PreviousStateMachineTypeName ??
GeneratedNames.MakeStateMachineTypeName(kickoffMethod.Name, kickoffMethodOrdinal, compilationState.ModuleBuilderOpt.CurrentGenerationOrdinal);
}
// new:
public MethodToStateMachineRewriter(
SyntheticBoundNodeFactory F,
MethodSymbol originalMethod,
FieldSymbol state,
IReadOnlySet<Symbol> hoistedVariables,
IReadOnlyDictionary<Symbol, CapturedSymbolReplacement> nonReusableLocalProxies,
SynthesizedLocalOrdinalsDispenser synthesizedLocalOrdinals,
VariableSlotAllocator slotAllocatorOpt,
int nextFreeHoistedLocalSlot,
DiagnosticBag diagnostics,
bool useFinalizerBookkeeping)
: base(slotAllocatorOpt, F.CompilationState, diagnostics)
{
Debug.Assert(F != null);
Debug.Assert(originalMethod != null);
Debug.Assert(state != null);
Debug.Assert(nonReusableLocalProxies != null);
Debug.Assert(diagnostics != null);
Debug.Assert(hoistedVariables != null);
Debug.Assert(nextFreeHoistedLocalSlot >= 0);
this.F = F;
this.stateField = state;
this.cachedState = F.SynthesizedLocal(F.SpecialType(SpecialType.System_Int32), syntax: F.Syntax, kind: SynthesizedLocalKind.StateMachineCachedState);
_useFinalizerBookkeeping = useFinalizerBookkeeping;
_hasFinalizerState = useFinalizerBookkeeping;
this.OriginalMethod = originalMethod;
_hoistedVariables = hoistedVariables;
_synthesizedLocalOrdinals = synthesizedLocalOrdinals;
_nextFreeHoistedLocalSlot = nextFreeHoistedLocalSlot;
foreach (var proxy in nonReusableLocalProxies)
{
this.proxies.Add(proxy.Key, proxy.Value);
}
}
// new:
public MethodToStateMachineRewriter(
SyntheticBoundNodeFactory F,
MethodSymbol originalMethod,
FieldSymbol state,
IReadOnlySet<Symbol> hoistedVariables,
IReadOnlyDictionary<Symbol, CapturedSymbolReplacement> nonReusableLocalProxies,
SynthesizedLocalOrdinalsDispenser synthesizedLocalOrdinals,
VariableSlotAllocator slotAllocatorOpt,
int nextFreeHoistedLocalSlot,
DiagnosticBag diagnostics,
bool useFinalizerBookkeeping)
: base(slotAllocatorOpt, F.CompilationState, diagnostics)
{
Debug.Assert(F != null);
Debug.Assert(originalMethod != null);
Debug.Assert(state != null);
Debug.Assert(nonReusableLocalProxies != null);
Debug.Assert(diagnostics != null);
Debug.Assert(hoistedVariables != null);
Debug.Assert(nextFreeHoistedLocalSlot >= 0);
this.F = F;
this.stateField = state;
this.cachedState = F.SynthesizedLocal(F.SpecialType(SpecialType.System_Int32), syntax: F.Syntax, kind: SynthesizedLocalKind.StateMachineCachedState);
_useFinalizerBookkeeping = useFinalizerBookkeeping;
_hasFinalizerState = useFinalizerBookkeeping;
this.OriginalMethod = originalMethod;
_hoistedVariables = hoistedVariables;
_synthesizedLocalOrdinals = synthesizedLocalOrdinals;
_nextFreeHoistedLocalSlot = nextFreeHoistedLocalSlot;
foreach (var proxy in nonReusableLocalProxies)
{
this.proxies.Add(proxy.Key, proxy.Value);
}
// create cache local for reference type "this" in Release
var thisParameter = originalMethod.ThisParameter;
CapturedSymbolReplacement thisProxy;
if ((object)thisParameter != null &&
thisParameter.Type.IsReferenceType &&
proxies.TryGetValue(thisParameter, out thisProxy) &&
F.Compilation.Options.OptimizationLevel == OptimizationLevel.Release)
{
BoundExpression thisProxyReplacement = thisProxy.Replacement(F.Syntax, frameType => F.This());
this.cachedThis = F.SynthesizedLocal(thisProxyReplacement.Type, syntax: F.Syntax, kind: SynthesizedLocalKind.FrameCache);
}
}
