public void CloseMethod(BoundStatement body)
{
Debug.Assert((object)CurrentMethod != null);
if (body.Kind != BoundKind.Block)
{
body = Block(body);
}
CompilationState.AddSynthesizedMethod(CurrentMethod, body);
CurrentMethod = null;
}
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>
/// Introduce a frame around the translation of the given node.
/// </summary>
/// <param name="node">The node whose translation should be translated to contain a frame</param>
/// <param name="frame">The frame for the translated node</param>
/// <param name="F">A function that computes the translation of the node. It receives lists of added statements and added symbols</param>
/// <returns>The translated statement, as returned from F</returns>
private T IntroduceFrame <T>(BoundNode node, LambdaFrame frame, Func <ArrayBuilder <BoundExpression>, ArrayBuilder <LocalSymbol>, T> F)
{
NamedTypeSymbol frameType = frame.ConstructIfGeneric(StaticCast <TypeSymbol> .From(currentTypeParameters));
LocalSymbol framePointer = new LambdaFrameLocalSymbol(this.topLevelMethod, frameType, CompilationState);
CSharpSyntaxNode syntax = node.Syntax;
// assign new frame to the frame variable
CompilationState.AddSynthesizedMethod(frame.Constructor, FlowAnalysisPass.AppendImplicitReturn(MethodCompiler.BindMethodBody(frame.Constructor, CompilationState, null), frame.Constructor));
var prologue = ArrayBuilder <BoundExpression> .GetInstance();
MethodSymbol constructor = frame.Constructor.AsMember(frameType);
Debug.Assert(frameType == constructor.ContainingType);
var newFrame = new BoundObjectCreationExpression(
syntax: syntax,
constructor: constructor);
prologue.Add(new BoundAssignmentOperator(syntax,
new BoundLocal(syntax, framePointer, null, frameType),
newFrame,
frameType));
CapturedSymbolReplacement oldInnermostFrameProxy = null;
if ((object)innermostFramePointer != null)
{
proxies.TryGetValue(innermostFramePointer, out oldInnermostFrameProxy);
if (analysis.needsParentFrame.Contains(node))
{
var capturedFrame = new LambdaCapturedVariable(frame, innermostFramePointer);
FieldSymbol frameParent = capturedFrame.AsMember(frameType);
BoundExpression left = new BoundFieldAccess(syntax, new BoundLocal(syntax, framePointer, null, frameType), frameParent, null);
BoundExpression right = FrameOfType(syntax, frameParent.Type as NamedTypeSymbol);
BoundExpression assignment = new BoundAssignmentOperator(syntax, left, right, left.Type);
if (this.currentMethod.MethodKind == MethodKind.Constructor && capturedFrame.Type == this.currentMethod.ContainingType && !this.seenBaseCall)
{
// Containing method is a constructor
// Initialization statement for the "this" proxy must be inserted
// after the constructor initializer statement block
// This insertion will be done by the delegate F
Debug.Assert(thisProxyInitDeferred == null);
thisProxyInitDeferred = assignment;
}
else
{
prologue.Add(assignment);
}
if (CompilationState.Emitting)
{
CompilationState.ModuleBuilderOpt.AddSynthesizedDefinition(frame, capturedFrame);
}
proxies[innermostFramePointer] = new CapturedToFrameSymbolReplacement(capturedFrame);
}
}
// Capture any parameters of this block. This would typically occur
// at the top level of a method or lambda with captured parameters.
// TODO: speed up the following by computing it in analysis.
foreach (var v in analysis.variablesCaptured)
{
BoundNode varNode;
if (!analysis.variableBlock.TryGetValue(v, out varNode) ||
varNode != node ||
analysis.declaredInsideExpressionLambda.Contains(v))
{
continue;
}
InitVariableProxy(syntax, v, framePointer, prologue);
}
Symbol oldInnermostFramePointer = innermostFramePointer;
innermostFramePointer = framePointer;
var addedLocals = ArrayBuilder <LocalSymbol> .GetInstance();
addedLocals.Add(framePointer);
framePointers.Add(frame, framePointer);
var result = F(prologue, addedLocals);
framePointers.Remove(frame);
innermostFramePointer = oldInnermostFramePointer;
if ((object)innermostFramePointer != null)
{
if (oldInnermostFrameProxy != null)
{
proxies[innermostFramePointer] = oldInnermostFrameProxy;
}
else
{
proxies.Remove(innermostFramePointer);
}
}
return(result);
}
