private void AddVariableCleanup(ArrayBuilder <BoundAssignmentOperator> cleanup, FieldSymbol field)
{
if (MightContainReferences(field.Type))
{
cleanup.Add(F.AssignmentExpression(F.Field(F.This(), field), F.NullOrDefault(field.Type)));
}
}
public override BoundNode VisitSpillBlock(BoundSpillBlock node)
{
var newStatements = ArrayBuilder <BoundStatement> .GetInstance();
spillFieldAllocator.AllocateFields(node.SpillTemps);
newStatements.AddRange(VisitList(node.Statements));
// Release references held by the spill temps:
foreach (var spill in node.SpillTemps)
{
if (spill.Type.IsManagedType)
{
var field = spillFieldAllocator.GetField(spill);
newStatements.Add(F.Assignment(F.Field(F.This(), field), F.NullOrDefault(field.Type)));
}
spillFieldAllocator.Free(spill);
}
return(F.Block(node.Locals, newStatements.ToReadOnlyAndFree()));
}
private static BoundBlock PrependImplicitInitializations(BoundBlock body, MethodSymbol method, ImmutableArray <FieldSymbol> implicitlyInitializedFields, TypeCompilationState compilationState, BindingDiagnosticBag diagnostics)
{
Debug.Assert(method.MethodKind == MethodKind.Constructor);
Debug.Assert(method.ContainingType.IsStructType());
var F = new SyntheticBoundNodeFactory(method, body.Syntax, compilationState, diagnostics);
var builder = ArrayBuilder <BoundStatement> .GetInstance(implicitlyInitializedFields.Length);
foreach (var field in implicitlyInitializedFields)
{
builder.Add(
F.ExpressionStatement(
F.AssignmentExpression(
F.Field(F.This(), field),
F.Default(field.Type))));
}
var initializations = F.HiddenSequencePoint(F.Block(builder.ToImmutableAndFree()));
return(body.Update(body.Locals, body.LocalFunctions, body.Statements.Insert(index: 0, initializations)));
}
private static BoundBlock PrependImplicitInitializations(BoundBlock body, MethodSymbol method, ImmutableArray <FieldSymbol> implicitlyInitializedFields, TypeCompilationState compilationState, BindingDiagnosticBag diagnostics)
{
Debug.Assert(method.MethodKind == MethodKind.Constructor);
Debug.Assert(method.ContainingType.IsStructType());
var syntax = body.Syntax;
var F = new SyntheticBoundNodeFactory(method, syntax, compilationState, diagnostics);
var builder = ArrayBuilder <BoundStatement> .GetInstance(implicitlyInitializedFields.Length + 1);
foreach (var field in implicitlyInitializedFields)
{
builder.Add(new BoundExpressionStatement(
syntax,
F.AssignmentExpression(
F.Field(F.This(), field),
F.Default(field.Type))));
}
builder.Add(body);
return(BoundBlock.SynthesizedNoLocals(syntax, builder.ToImmutableAndFree()));
}
// NOTE: can return null if the method has no body.
internal static BoundBlock BindMethodBody(MethodSymbol method, TypeCompilationState compilationState, DiagnosticBag diagnostics, bool generateDebugInfo, out ConsList<Imports> debugImports)
{
debugImports = null;
BoundStatement constructorInitializer = null;
BoundBlock body;
var compilation = method.DeclaringCompilation;
var sourceMethod = method as SourceMethodSymbol;
if ((object)sourceMethod != null)
{
if (sourceMethod.IsExtern)
{
if (sourceMethod.BlockSyntax == null)
{
// Generate warnings only if we are not generating ERR_ExternHasBody error
GenerateExternalMethodWarnings(sourceMethod, diagnostics);
}
return null;
}
else if (sourceMethod.IsParameterlessValueTypeConstructor(requireSynthesized: true))
{
// No body for default struct constructor.
return null;
}
var blockSyntax = sourceMethod.BlockSyntax;
if (blockSyntax != null)
{
var factory = compilation.GetBinderFactory(sourceMethod.SyntaxTree);
var inMethodBinder = factory.GetBinder(blockSyntax);
var binder = new ExecutableCodeBinder(blockSyntax, sourceMethod, inMethodBinder);
body = binder.BindBlock(blockSyntax, diagnostics);
if (generateDebugInfo)
{
debugImports = binder.ImportsList;
}
if (inMethodBinder.IsDirectlyInIterator)
{
foreach (var parameter in method.Parameters)
{
if (parameter.RefKind != RefKind.None)
{
diagnostics.Add(ErrorCode.ERR_BadIteratorArgType, parameter.Locations[0]);
}
else if (parameter.Type.IsUnsafe())
{
diagnostics.Add(ErrorCode.ERR_UnsafeIteratorArgType, parameter.Locations[0]);
}
}
if (sourceMethod.IsUnsafe && compilation.Options.AllowUnsafe) // Don't cascade
{
diagnostics.Add(ErrorCode.ERR_IllegalInnerUnsafe, sourceMethod.Locations[0]);
}
if (sourceMethod.IsVararg)
{
// error CS1636: __arglist is not allowed in the parameter list of iterators
diagnostics.Add(ErrorCode.ERR_VarargsIterator, sourceMethod.Locations[0]);
}
}
}
else // for [if (blockSyntax != null)]
{
var property = sourceMethod.AssociatedSymbol as SourcePropertySymbol;
if ((object)property != null && property.IsAutoProperty)
{
return MethodBodySynthesizer.ConstructAutoPropertyAccessorBody(sourceMethod);
}
if (sourceMethod.IsPrimaryCtor)
{
body = null;
}
else
{
return null;
}
}
}
else
{
// synthesized methods should return their bound bodies
body = null;
}
// delegates have constructors but not constructor initializers
if (method.MethodKind == MethodKind.Constructor && !method.ContainingType.IsDelegateType())
{
var initializerInvocation = BindConstructorInitializer(method, diagnostics, compilation);
if (initializerInvocation != null)
{
constructorInitializer = new BoundExpressionStatement(initializerInvocation.Syntax, initializerInvocation) { WasCompilerGenerated = true };
Debug.Assert(initializerInvocation.HasAnyErrors || constructorInitializer.IsConstructorInitializer(), "Please keep this bound node in sync with BoundNodeExtensions.IsConstructorInitializer.");
}
}
var statements = ArrayBuilder<BoundStatement>.GetInstance();
if (constructorInitializer != null)
{
statements.Add(constructorInitializer);
}
if ((object)sourceMethod != null && sourceMethod.IsPrimaryCtor && (object)((SourceMemberContainerTypeSymbol)sourceMethod.ContainingType).PrimaryCtor == (object)sourceMethod)
{
Debug.Assert(method.MethodKind == MethodKind.Constructor && !method.ContainingType.IsDelegateType());
Debug.Assert(body == null);
if (sourceMethod.ParameterCount > 0)
{
var factory = new SyntheticBoundNodeFactory(sourceMethod, sourceMethod.SyntaxNode, compilationState, diagnostics);
factory.CurrentMethod = sourceMethod;
foreach (var parameter in sourceMethod.Parameters)
{
FieldSymbol field = parameter.PrimaryConstructorParameterBackingField;
if ((object)field != null)
{
statements.Add(factory.Assignment(factory.Field(factory.This(), field),
factory.Parameter(parameter)));
}
}
}
}
if (body != null)
{
statements.Add(body);
}
CSharpSyntaxNode syntax = body != null ? body.Syntax : method.GetNonNullSyntaxNode();
BoundBlock block;
if (statements.Count == 1 && statements[0].Kind == ((body == null) ? BoundKind.Block : body.Kind))
{
// most common case - we just have a single block for the body.
block = (BoundBlock)statements[0];
statements.Free();
}
else
{
block = new BoundBlock(syntax, default(ImmutableArray<LocalSymbol>), statements.ToImmutableAndFree()) { WasCompilerGenerated = true };
}
return method.MethodKind == MethodKind.Destructor ? MethodBodySynthesizer.ConstructDestructorBody(syntax, method, block) : block;
}
/// <summary>
/// Generate the GetEnumerator() method for iterators and GetAsyncEnumerator() for async-iterators.
/// </summary>
protected SynthesizedImplementationMethod GenerateIteratorGetEnumerator(MethodSymbol getEnumeratorMethod, ref BoundExpression managedThreadId, int initialState)
{
// Produces:
// {StateMachineType} result;
// if (this.initialThreadId == {managedThreadId} && this.state == -2)
// {
// this.state = {initialState};
// extraReset
// result = this;
// }
// else
// {
// result = new {StateMachineType}({initialState});
// }
// result.parameter = this.parameterProxy; // copy all of the parameter proxies
// The implementation doesn't depend on the method body of the iterator method.
// Only on its parameters and staticness.
var getEnumerator = OpenMethodImplementation(
getEnumeratorMethod,
hasMethodBodyDependency: false);
var bodyBuilder = ArrayBuilder <BoundStatement> .GetInstance();
// {StateMachineType} result;
var resultVariable = F.SynthesizedLocal(stateMachineType, null);
// result = new {StateMachineType}({initialState})
BoundStatement makeIterator = F.Assignment(F.Local(resultVariable), F.New(stateMachineType.Constructor, F.Literal(initialState)));
var thisInitialized = F.GenerateLabel("thisInitialized");
if ((object)initialThreadIdField != null)
{
managedThreadId = MakeCurrentThreadId();
var thenBuilder = ArrayBuilder <BoundStatement> .GetInstance(4);
thenBuilder.Add(
// this.state = {initialState};
F.Assignment(F.Field(F.This(), stateField), F.Literal(initialState)));
thenBuilder.Add(
// result = this;
F.Assignment(F.Local(resultVariable), F.This()));
var extraReset = GetExtraResetForIteratorGetEnumerator();
if (extraReset != null)
{
thenBuilder.Add(extraReset);
}
thenBuilder.Add(
method.IsStatic || method.ThisParameter.Type.IsReferenceType ? // if this is a reference type, no need to copy it since it is not assignable
F.Goto(thisInitialized) : // goto thisInitialized
(BoundStatement)F.StatementList());
makeIterator = F.If(
// if (this.state == -2 && this.initialThreadId == Thread.CurrentThread.ManagedThreadId)
condition: F.LogicalAnd(
F.IntEqual(F.Field(F.This(), stateField), F.Literal(StateMachineStates.FinishedStateMachine)),
F.IntEqual(F.Field(F.This(), initialThreadIdField), managedThreadId)),
thenClause: F.Block(thenBuilder.ToImmutableAndFree()),
elseClauseOpt: makeIterator);
}
bodyBuilder.Add(makeIterator);
// Initialize all the parameter copies
var copySrc = initialParameters;
var copyDest = nonReusableLocalProxies;
if (!method.IsStatic)
{
// starting with "this"
CapturedSymbolReplacement proxy;
if (copyDest.TryGetValue(method.ThisParameter, out proxy))
{
bodyBuilder.Add(
F.Assignment(
proxy.Replacement(F.Syntax, stateMachineType => F.Local(resultVariable)),
copySrc[method.ThisParameter].Replacement(F.Syntax, stateMachineType => F.This())));
}
}
bodyBuilder.Add(F.Label(thisInitialized));
foreach (var parameter in method.Parameters)
{
CapturedSymbolReplacement proxy;
if (copyDest.TryGetValue(parameter, out proxy))
{
bodyBuilder.Add(
F.Assignment(
proxy.Replacement(F.Syntax, stateMachineType => F.Local(resultVariable)),
copySrc[parameter].Replacement(F.Syntax, stateMachineType => F.This())));
}
}
bodyBuilder.Add(F.Return(F.Local(resultVariable)));
F.CloseMethod(F.Block(ImmutableArray.Create(resultVariable), bodyBuilder.ToImmutableAndFree()));
return(getEnumerator);
}
/// <summary>
/// Translate a statement that declares a given set of locals. Also allocates and frees hoisted temps as
/// required for the translation.
/// </summary>
/// <param name="locals">The set of locals declared in the original version of this statement</param>
/// <param name="wrapped">A delegate to return the translation of the body of this statement</param>
private BoundNode PossibleIteratorScope(ImmutableArray <LocalSymbol> locals, Func <BoundStatement> wrapped)
{
if (locals.IsDefaultOrEmpty)
{
return(wrapped());
}
var proxyFields = ArrayBuilder <SynthesizedFieldSymbolBase> .GetInstance();
foreach (var local in locals)
{
if (!VariablesCaptured.Contains(local))
{
continue;
}
CapturedSymbolReplacement proxy;
if (proxies.TryGetValue(local, out proxy))
{
// All of the user-declared variables have pre-allocated proxies
var field = proxy.HoistedField;
Debug.Assert((object)field != null);
Debug.Assert(local.DeclarationKind != LocalDeclarationKind.CompilerGenerated); // temps have lazily allocated proxies
if (local.DeclarationKind != LocalDeclarationKind.CompilerGenerated)
{
proxyFields.Add(field);
}
}
else
{
if (local.RefKind == RefKind.None)
{
SynthesizedFieldSymbolBase field = MakeHoistedTemp(local, TypeMap.SubstituteType(local.Type));
proxy = new CapturedToFrameSymbolReplacement(field);
proxies.Add(local, proxy);
}
// ref temporary variables have proxies that are allocated on demand
// See VisitAssignmentOperator.
}
}
var translatedStatement = wrapped();
// produce code to free (e.g. mark as available for reuse) and clear (e.g. set to null) the proxies for any temps for these locals
var clearTemps = ArrayBuilder <BoundAssignmentOperator> .GetInstance();
foreach (var local in locals)
{
ArrayBuilder <SynthesizedFieldSymbolBase> frees;
if (freeTempsMap.TryGetValue(local, out frees))
{
Debug.Assert(local.DeclarationKind == LocalDeclarationKind.CompilerGenerated); // only temps are managed this way
freeTempsMap.Remove(local);
foreach (var field in frees)
{
if (MightContainReferences(field.Type))
{
clearTemps.Add(F.AssignmentExpression(F.Field(F.This(), field), F.NullOrDefault(field.Type)));
}
FreeTemp(field);
}
frees.Free();
}
}
if (clearTemps.Count != 0)
{
translatedStatement = F.Block(
translatedStatement,
F.Block(clearTemps.Select(e => F.ExpressionStatement(e)).AsImmutable <BoundStatement>())
);
}
clearTemps.Free();
// wrap the node in an iterator scope for debugging
if (proxyFields.Count != 0)
{
translatedStatement = new BoundIteratorScope(F.Syntax, proxyFields.ToImmutable(), translatedStatement);
}
proxyFields.Free();
return(translatedStatement);
}
internal LoweredDynamicOperation MakeDynamicOperation(
BoundExpression binderConstruction,
BoundExpression loweredReceiver,
RefKind receiverRefKind,
ImmutableArray <BoundExpression> loweredArguments,
ImmutableArray <RefKind> refKinds,
BoundExpression loweredRight,
TypeSymbol resultType)
{
Debug.Assert(!loweredArguments.IsDefault);
// get well-known types and members we need:
NamedTypeSymbol delegateTypeOverMethodTypeParameters = GetDelegateType(loweredReceiver, receiverRefKind, loweredArguments, refKinds, loweredRight, resultType);
NamedTypeSymbol callSiteTypeGeneric = _factory.WellKnownType(WellKnownType.System_Runtime_CompilerServices_CallSite_T);
MethodSymbol callSiteFactoryGeneric = _factory.WellKnownMethod(WellKnownMember.System_Runtime_CompilerServices_CallSite_T__Create);
FieldSymbol callSiteTargetFieldGeneric = (FieldSymbol)_factory.WellKnownMember(WellKnownMember.System_Runtime_CompilerServices_CallSite_T__Target);
MethodSymbol delegateInvoke;
if (binderConstruction == null ||
(object)delegateTypeOverMethodTypeParameters == null ||
delegateTypeOverMethodTypeParameters.IsErrorType() ||
(object)(delegateInvoke = delegateTypeOverMethodTypeParameters.DelegateInvokeMethod) == null ||
callSiteTypeGeneric.IsErrorType() ||
(object)callSiteFactoryGeneric == null ||
(object)callSiteTargetFieldGeneric == null)
{
// CS1969: One or more types required to compile a dynamic expression cannot be found.
// Dev11 reports it with source location for each dynamic operation, which results in many error messages.
// The diagnostic that names the specific missing type or member has already been reported.
_factory.Diagnostics.Add(ErrorCode.ERR_DynamicRequiredTypesMissing, NoLocation.Singleton);
return(LoweredDynamicOperation.Bad(loweredReceiver, loweredArguments, loweredRight, resultType));
}
if ((object)_currentDynamicCallSiteContainer == null)
{
_currentDynamicCallSiteContainer = CreateCallSiteContainer(_factory, _methodOrdinal);
}
var containerDef = (SynthesizedContainer)_currentDynamicCallSiteContainer.OriginalDefinition;
var methodToContainerTypeParametersMap = containerDef.TypeMap;
ImmutableArray <LocalSymbol> temps = MakeTempsForDiscardArguments(ref loweredArguments);
var callSiteType = callSiteTypeGeneric.Construct(new[] { delegateTypeOverMethodTypeParameters });
var callSiteFactoryMethod = callSiteFactoryGeneric.AsMember(callSiteType);
var callSiteTargetField = callSiteTargetFieldGeneric.AsMember(callSiteType);
var callSiteField = DefineCallSiteStorageSymbol(containerDef, delegateTypeOverMethodTypeParameters, methodToContainerTypeParametersMap);
var callSiteFieldAccess = _factory.Field(null, callSiteField);
var callSiteArguments = GetCallSiteArguments(callSiteFieldAccess, loweredReceiver, loweredArguments, loweredRight);
var nullCallSite = _factory.Null(callSiteField.Type);
var siteInitialization = _factory.Conditional(
_factory.ObjectEqual(callSiteFieldAccess, nullCallSite),
_factory.AssignmentExpression(callSiteFieldAccess, _factory.Call(null, callSiteFactoryMethod, binderConstruction)),
nullCallSite,
callSiteField.Type);
var siteInvocation = _factory.Call(
_factory.Field(callSiteFieldAccess, callSiteTargetField),
delegateInvoke,
callSiteArguments);
return(new LoweredDynamicOperation(_factory, siteInitialization, siteInvocation, resultType, temps));
}
// NOTE: can return null if the method has no body.
internal static BoundBlock BindMethodBody(MethodSymbol method, TypeCompilationState compilationState, DiagnosticBag diagnostics, bool generateDebugInfo, out ConsList <Imports> debugImports)
{
debugImports = null;
BoundStatement constructorInitializer = null;
BoundBlock body;
var compilation = method.DeclaringCompilation;
var sourceMethod = method as SourceMethodSymbol;
if ((object)sourceMethod != null)
{
if (sourceMethod.IsExtern)
{
if (sourceMethod.BlockSyntax == null)
{
// Generate warnings only if we are not generating ERR_ExternHasBody error
GenerateExternalMethodWarnings(sourceMethod, diagnostics);
}
return(null);
}
else if (sourceMethod.IsParameterlessValueTypeConstructor(requireSynthesized: true))
{
// No body for default struct constructor.
return(null);
}
var blockSyntax = sourceMethod.BlockSyntax;
if (blockSyntax != null)
{
var factory = compilation.GetBinderFactory(sourceMethod.SyntaxTree);
var inMethodBinder = factory.GetBinder(blockSyntax);
var binder = new ExecutableCodeBinder(blockSyntax, sourceMethod, inMethodBinder);
body = binder.BindBlock(blockSyntax, diagnostics);
if (generateDebugInfo)
{
debugImports = binder.ImportsList;
}
if (inMethodBinder.IsDirectlyInIterator)
{
foreach (var parameter in method.Parameters)
{
if (parameter.RefKind != RefKind.None)
{
diagnostics.Add(ErrorCode.ERR_BadIteratorArgType, parameter.Locations[0]);
}
else if (parameter.Type.IsUnsafe())
{
diagnostics.Add(ErrorCode.ERR_UnsafeIteratorArgType, parameter.Locations[0]);
}
}
if (sourceMethod.IsUnsafe && compilation.Options.AllowUnsafe) // Don't cascade
{
diagnostics.Add(ErrorCode.ERR_IllegalInnerUnsafe, sourceMethod.Locations[0]);
}
if (sourceMethod.IsVararg)
{
// error CS1636: __arglist is not allowed in the parameter list of iterators
diagnostics.Add(ErrorCode.ERR_VarargsIterator, sourceMethod.Locations[0]);
}
}
}
else // for [if (blockSyntax != null)]
{
var property = sourceMethod.AssociatedSymbol as SourcePropertySymbol;
if ((object)property != null && property.IsAutoProperty)
{
return(MethodBodySynthesizer.ConstructAutoPropertyAccessorBody(sourceMethod));
}
if (sourceMethod.IsPrimaryCtor)
{
body = null;
}
else
{
return(null);
}
}
}
else
{
// synthesized methods should return their bound bodies
body = null;
}
// delegates have constructors but not constructor initializers
if (method.MethodKind == MethodKind.Constructor && !method.ContainingType.IsDelegateType())
{
var initializerInvocation = BindConstructorInitializer(method, diagnostics, compilation);
if (initializerInvocation != null)
{
constructorInitializer = new BoundExpressionStatement(initializerInvocation.Syntax, initializerInvocation)
{
WasCompilerGenerated = true
};
Debug.Assert(initializerInvocation.HasAnyErrors || constructorInitializer.IsConstructorInitializer(), "Please keep this bound node in sync with BoundNodeExtensions.IsConstructorInitializer.");
}
}
var statements = ArrayBuilder <BoundStatement> .GetInstance();
if (constructorInitializer != null)
{
statements.Add(constructorInitializer);
}
if ((object)sourceMethod != null && sourceMethod.IsPrimaryCtor && (object)((SourceMemberContainerTypeSymbol)sourceMethod.ContainingType).PrimaryCtor == (object)sourceMethod)
{
Debug.Assert(method.MethodKind == MethodKind.Constructor && !method.ContainingType.IsDelegateType());
Debug.Assert(body == null);
if (sourceMethod.ParameterCount > 0)
{
var factory = new SyntheticBoundNodeFactory(sourceMethod, sourceMethod.SyntaxNode, compilationState, diagnostics);
factory.CurrentMethod = sourceMethod;
foreach (var parameter in sourceMethod.Parameters)
{
FieldSymbol field = parameter.PrimaryConstructorParameterBackingField;
if ((object)field != null)
{
statements.Add(factory.Assignment(factory.Field(factory.This(), field),
factory.Parameter(parameter)));
}
}
}
}
if (body != null)
{
statements.Add(body);
}
CSharpSyntaxNode syntax = body != null ? body.Syntax : method.GetNonNullSyntaxNode();
BoundBlock block;
if (statements.Count == 1 && statements[0].Kind == ((body == null) ? BoundKind.Block : body.Kind))
{
// most common case - we just have a single block for the body.
block = (BoundBlock)statements[0];
statements.Free();
}
else
{
block = new BoundBlock(syntax, default(ImmutableArray <LocalSymbol>), statements.ToImmutableAndFree())
{
WasCompilerGenerated = true
};
}
return(method.MethodKind == MethodKind.Destructor ? MethodBodySynthesizer.ConstructDestructorBody(syntax, method, block) : block);
}
private BoundNode RewriteLambdaConversion(BoundLambda node)
{
var wasInExpressionLambda = inExpressionLambda;
inExpressionLambda = inExpressionLambda || node.Type.IsExpressionTree();
if (inExpressionLambda)
{
var newType = VisitType(node.Type);
var newBody = (BoundBlock)Visit(node.Body);
node = node.Update(node.Symbol, newBody, node.Diagnostics, node.Binder, newType);
var result0 = wasInExpressionLambda ? node : ExpressionLambdaRewriter.RewriteLambda(node, CompilationState, Diagnostics);
inExpressionLambda = wasInExpressionLambda;
return(result0);
}
NamedTypeSymbol translatedLambdaContainer;
BoundNode lambdaScope = null;
if (analysis.lambdaScopes.TryGetValue(node.Symbol, out lambdaScope))
{
translatedLambdaContainer = frames[lambdaScope];
}
else
{
translatedLambdaContainer = topLevelMethod.ContainingType;
}
// Move the body of the lambda to a freshly generated synthetic method on its frame.
bool lambdaIsStatic = analysis.captures[node.Symbol].IsEmpty();
var synthesizedMethod = new SynthesizedLambdaMethod(translatedLambdaContainer, topLevelMethod, node, lambdaIsStatic, CompilationState);
if (CompilationState.Emitting)
{
CompilationState.ModuleBuilderOpt.AddSynthesizedDefinition(translatedLambdaContainer, synthesizedMethod);
}
for (int i = 0; i < node.Symbol.ParameterCount; i++)
{
parameterMap.Add(node.Symbol.Parameters[i], synthesizedMethod.Parameters[i]);
}
// rewrite the lambda body as the generated method's body
var oldMethod = currentMethod;
var oldFrameThis = currentFrameThis;
var oldTypeParameters = currentTypeParameters;
var oldInnermostFramePointer = innermostFramePointer;
var oldTypeMap = currentLambdaBodyTypeMap;
var oldAddedStatements = addedStatements;
var oldAddedLocals = addedLocals;
addedStatements = null;
addedLocals = null;
// switch to the generated method
currentMethod = synthesizedMethod;
if (lambdaIsStatic)
{
// no link from a static lambda to its container
innermostFramePointer = currentFrameThis = null;
}
else
{
currentFrameThis = synthesizedMethod.ThisParameter;
innermostFramePointer = null;
framePointers.TryGetValue(translatedLambdaContainer, out innermostFramePointer);
}
if (translatedLambdaContainer.OriginalDefinition is LambdaFrame)
{
currentTypeParameters = translatedLambdaContainer.TypeParameters;
currentLambdaBodyTypeMap = ((LambdaFrame)translatedLambdaContainer).TypeMap;
}
else
{
currentTypeParameters = synthesizedMethod.TypeParameters;
currentLambdaBodyTypeMap = new TypeMap(topLevelMethod.TypeParameters, currentTypeParameters);
}
var body = AddStatementsIfNeeded((BoundStatement)VisitBlock(node.Body));
CheckLocalsDefined(body);
CompilationState.AddSynthesizedMethod(synthesizedMethod, body);
// return to the old method
currentMethod = oldMethod;
currentFrameThis = oldFrameThis;
currentTypeParameters = oldTypeParameters;
innermostFramePointer = oldInnermostFramePointer;
currentLambdaBodyTypeMap = oldTypeMap;
addedLocals = oldAddedLocals;
addedStatements = oldAddedStatements;
// Rewrite the lambda expression (and the enclosing anonymous method conversion) as a delegate creation expression
NamedTypeSymbol constructedFrame = (translatedLambdaContainer is LambdaFrame) ? translatedLambdaContainer.ConstructIfGeneric(StaticCast <TypeSymbol> .From(currentTypeParameters)) : translatedLambdaContainer;
BoundExpression receiver = lambdaIsStatic ? new BoundTypeExpression(node.Syntax, null, constructedFrame) : FrameOfType(node.Syntax, constructedFrame);
MethodSymbol referencedMethod = synthesizedMethod.AsMember(constructedFrame);
if (referencedMethod.IsGenericMethod)
{
referencedMethod = referencedMethod.Construct(StaticCast <TypeSymbol> .From(currentTypeParameters));
}
TypeSymbol type = this.VisitType(node.Type);
BoundExpression result = new BoundDelegateCreationExpression(
node.Syntax,
receiver,
referencedMethod,
isExtensionMethod: false,
type: type);
// if the block containing the lambda is not the innermost block,
// or the lambda is static, then the lambda object should be cached in its frame.
// NOTE: we are not caching static lambdas in static ctors - cannot reuse such cache.
var shouldCacheForStaticMethod = lambdaIsStatic &&
currentMethod.MethodKind != MethodKind.StaticConstructor &&
!referencedMethod.IsGenericMethod;
// NOTE: We require "lambdaScope != null".
// We do not want to introduce a field into an actual user's class (not a synthetic frame).
var shouldCacheInLoop = lambdaScope != null &&
lambdaScope != analysis.blockParent[node.Body] &&
InLoopOrLambda(node.Syntax, lambdaScope.Syntax);
if (shouldCacheForStaticMethod || shouldCacheInLoop)
{
// replace the expression "new Delegate(frame.M)" with "(frame.cache == null) ? (frame.cache = new Delegate(frame.M)) : frame.cache"
var F = new SyntheticBoundNodeFactory(currentMethod, node.Syntax, CompilationState, Diagnostics);
try
{
var cacheVariableName = GeneratedNames.MakeLambdaCacheName(CompilationState.GenerateTempNumber());
BoundExpression cacheVariable;
if (shouldCacheForStaticMethod || shouldCacheInLoop && translatedLambdaContainer is LambdaFrame)
{
var cacheVariableType = lambdaIsStatic ? type : (translatedLambdaContainer as LambdaFrame).TypeMap.SubstituteType(type);
var cacheField = new SynthesizedFieldSymbol(translatedLambdaContainer, cacheVariableType, cacheVariableName, isPublic: !lambdaIsStatic, isStatic: lambdaIsStatic);
CompilationState.ModuleBuilderOpt.AddSynthesizedDefinition(translatedLambdaContainer, cacheField);
cacheVariable = F.Field(receiver, cacheField.AsMember(constructedFrame)); //NOTE: the field was added to the unconstructed frame type.
}
else
{
// the lambda captures at most the "this" of the enclosing method. We cache its delegate in a local variable.
var cacheLocal = F.SynthesizedLocal(type, cacheVariableName);
if (addedLocals == null)
{
addedLocals = ArrayBuilder <LocalSymbol> .GetInstance();
}
addedLocals.Add(cacheLocal);
if (addedStatements == null)
{
addedStatements = ArrayBuilder <BoundStatement> .GetInstance();
}
cacheVariable = F.Local(cacheLocal);
addedStatements.Add(F.Assignment(cacheVariable, F.Null(type)));
}
result = F.Coalesce(cacheVariable, F.AssignmentExpression(cacheVariable, result));
}
catch (SyntheticBoundNodeFactory.MissingPredefinedMember ex)
{
Diagnostics.Add(ex.Diagnostic);
return(new BoundBadExpression(F.Syntax, LookupResultKind.Empty, ImmutableArray <Symbol> .Empty, ImmutableArray.Create <BoundNode>(node), node.Type));
}
}
return(result);
}
/// <summary>
/// Generate the GetEnumerator() method for iterators and GetAsyncEnumerator() for async-iterators.
/// </summary>
protected SynthesizedImplementationMethod GenerateIteratorGetEnumerator(MethodSymbol getEnumeratorMethod, ref BoundExpression managedThreadId, int initialState)
{
// Produces:
// {StateMachineType} result;
// if (this.initialThreadId == {managedThreadId} && this.state == -2)
// {
// this.state = {initialState};
// extraReset
// result = this;
// }
// else
// {
// result = new {StateMachineType}({initialState});
// }
//
// // Initialize each parameter fields
// result.parameter = this.parameterProxy;
// OR
// if (token.Equals(default)) { result.parameter = this.parameterProxy; } else { result.parameter = token; } // for async-enumerable parameters marked with [EnumeratorCancellation]
// The implementation doesn't depend on the method body of the iterator method.
// Only on its parameters and staticness.
var getEnumerator = OpenMethodImplementation(
getEnumeratorMethod,
hasMethodBodyDependency: false);
var bodyBuilder = ArrayBuilder <BoundStatement> .GetInstance();
// {StateMachineType} result;
var resultVariable = F.SynthesizedLocal(stateMachineType, null);
// result = new {StateMachineType}({initialState})
BoundStatement makeIterator = F.Assignment(F.Local(resultVariable), F.New(stateMachineType.Constructor, F.Literal(initialState)));
var thisInitialized = F.GenerateLabel("thisInitialized");
if ((object)initialThreadIdField != null)
{
managedThreadId = MakeCurrentThreadId();
var thenBuilder = ArrayBuilder <BoundStatement> .GetInstance(4);
thenBuilder.Add(
// this.state = {initialState};
F.Assignment(F.Field(F.This(), stateField), F.Literal(initialState)));
thenBuilder.Add(
// result = this;
F.Assignment(F.Local(resultVariable), F.This()));
var extraReset = GetExtraResetForIteratorGetEnumerator();
if (extraReset != null)
{
thenBuilder.Add(extraReset);
}
if (method.IsStatic || method.ThisParameter.Type.IsReferenceType)
{
// if this is a reference type, no need to copy it since it is not assignable
thenBuilder.Add(
// goto thisInitialized;
F.Goto(thisInitialized));
}
makeIterator = F.If(
// if (this.state == -2 && this.initialThreadId == Thread.CurrentThread.ManagedThreadId)
condition: F.LogicalAnd(
F.IntEqual(F.Field(F.This(), stateField), F.Literal(StateMachineStates.FinishedStateMachine)),
F.IntEqual(F.Field(F.This(), initialThreadIdField), managedThreadId)),
thenClause: F.Block(thenBuilder.ToImmutableAndFree()),
elseClauseOpt: makeIterator);
}
bodyBuilder.Add(makeIterator);
// Initialize all the parameter copies
var copySrc = initialParameters;
var copyDest = nonReusableLocalProxies;
if (!method.IsStatic)
{
// starting with "this"
CapturedSymbolReplacement proxy;
if (copyDest.TryGetValue(method.ThisParameter, out proxy))
{
bodyBuilder.Add(
F.Assignment(
proxy.Replacement(F.Syntax, stateMachineType => F.Local(resultVariable)),
copySrc[method.ThisParameter].Replacement(F.Syntax, stateMachineType => F.This())));
}
}
bodyBuilder.Add(F.Label(thisInitialized));
foreach (var parameter in method.Parameters)
{
CapturedSymbolReplacement proxy;
if (copyDest.TryGetValue(parameter, out proxy))
{
// result.parameter = this.parameterProxy;
BoundExpression left = proxy.Replacement(F.Syntax, stateMachineType => F.Local(resultVariable));
BoundStatement copy = F.Assignment(
left,
copySrc[parameter].Replacement(F.Syntax, stateMachineType => F.This()));
if (this.method.IsAsync)
{
ParameterSymbol tokenParameter = getEnumeratorMethod.Parameters[0];
if (hasEnumeratorCancellationAttribute(parameter))
{
// For any async-enumerable parameter marked with [EnumeratorCancellation] attribute, conditionally copy GetAsyncEnumerator's cancellation token parameter instead
// if (token.Equals(default))
// result.parameter = this.parameterProxy;
// else
// result.parameter = token;
copy = F.If(
// if (token.Equals(default))
F.Call(F.Parameter(tokenParameter), WellKnownMember.System_Threading_CancellationToken__Equals, F.Default(tokenParameter.Type)),
// result.parameter = this.parameterProxy;
copy,
// result.parameter = token;
F.Assignment(left, F.Parameter(tokenParameter)));
}
}
bodyBuilder.Add(copy);
}
}
bodyBuilder.Add(F.Return(F.Local(resultVariable)));
F.CloseMethod(F.Block(ImmutableArray.Create(resultVariable), bodyBuilder.ToImmutableAndFree()));
return(getEnumerator);
