private static MethodSymbol SubstituteTypeParameters(MethodSymbol method)
{
Debug.Assert(method.IsDefinition);
var typeParameters = method.TypeParameters;
int n = typeParameters.Length;
if (n == 0)
{
return method;
}
return method.Construct(IndexedTypeParameterSymbol.Take(n).Cast<TypeParameterSymbol, TypeSymbol>());
}
/// <summary>
/// Get the MethodSymbol for System.Threading.Interlocked.CompareExchange<T> for a given T.
/// </summary>
private static MethodSymbol GetConstructedCompareExchangeMethod(TypeSymbol typeArg, CSharpCompilation compilation, Location errorLocation, DiagnosticBag diagnostics)
{
MethodSymbol compareExchangeDefinition = (MethodSymbol)compilation.GetWellKnownTypeMember(WellKnownMember.System_Threading_Interlocked__CompareExchange_T);
if ((object)compareExchangeDefinition == null)
{
MemberDescriptor memberDescriptor = WellKnownMembers.GetDescriptor(WellKnownMember.System_Threading_Interlocked__CompareExchange_T);
WellKnownType containingType = (WellKnownType)memberDescriptor.DeclaringTypeId;
diagnostics.Add(ErrorCode.ERR_MissingPredefinedMember, errorLocation, containingType.GetMetadataName(), memberDescriptor.Name);
return(null);
}
return(compareExchangeDefinition.Construct(ImmutableArray.Create <TypeSymbol>(typeArg)));
}
/// <summary>
/// Generate a thread-safe accessor for a regular field-like event.
///
/// DelegateType tmp0 = _event; //backing field
/// DelegateType tmp1;
/// DelegateType tmp2;
/// do {
/// tmp1 = tmp0;
/// tmp2 = (DelegateType)Delegate.Combine(tmp1, value); //Remove for -=
/// tmp0 = Interlocked.CompareExchange<DelegateType>(ref _event, tmp2, tmp1);
/// } while ((object)tmp0 != (object)tmp1);
///
/// Note, if System.Threading.Interlocked.CompareExchange<T> is not available,
/// we emit the following code and mark the method Synchronized (unless it is a struct).
///
/// _event = (DelegateType)Delegate.Combine(_event, value); //Remove for -=
///
/// </summary>
internal static BoundBlock ConstructFieldLikeEventAccessorBody_Regular(SourceEventSymbol eventSymbol, bool isAddMethod, CSharpCompilation compilation, DiagnosticBag diagnostics)
{
CSharpSyntaxNode syntax = eventSymbol.CSharpSyntaxNode;
TypeSymbol delegateType = eventSymbol.Type;
MethodSymbol accessor = isAddMethod ? eventSymbol.AddMethod : eventSymbol.RemoveMethod;
ParameterSymbol thisParameter = accessor.ThisParameter;
TypeSymbol boolType = compilation.GetSpecialType(SpecialType.System_Boolean);
SpecialMember updateMethodId = isAddMethod ? SpecialMember.System_Delegate__Combine : SpecialMember.System_Delegate__Remove;
MethodSymbol updateMethod = (MethodSymbol)compilation.GetSpecialTypeMember(updateMethodId);
BoundStatement @return = new BoundReturnStatement(syntax,
expressionOpt: null)
{
WasCompilerGenerated = true
};
if (updateMethod == null)
{
MemberDescriptor memberDescriptor = SpecialMembers.GetDescriptor(updateMethodId);
diagnostics.Add(new CSDiagnostic(new CSDiagnosticInfo(ErrorCode.ERR_MissingPredefinedMember,
memberDescriptor.DeclaringTypeMetadataName,
memberDescriptor.Name),
syntax.Location));
return(new BoundBlock(syntax,
locals: ImmutableArray <LocalSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(@return))
{
WasCompilerGenerated = true
});
}
Binder.ReportUseSiteDiagnostics(updateMethod, diagnostics, syntax);
BoundThisReference fieldReceiver = eventSymbol.IsStatic ?
null :
new BoundThisReference(syntax, thisParameter.Type)
{
WasCompilerGenerated = true
};
BoundFieldAccess boundBackingField = new BoundFieldAccess(syntax,
receiver: fieldReceiver,
fieldSymbol: eventSymbol.AssociatedField,
constantValueOpt: null)
{
WasCompilerGenerated = true
};
BoundParameter boundParameter = new BoundParameter(syntax,
parameterSymbol: accessor.Parameters[0])
{
WasCompilerGenerated = true
};
BoundExpression delegateUpdate;
MethodSymbol compareExchangeMethod = (MethodSymbol)compilation.GetWellKnownTypeMember(WellKnownMember.System_Threading_Interlocked__CompareExchange_T);
if ((object)compareExchangeMethod == null)
{
// (DelegateType)Delegate.Combine(_event, value)
delegateUpdate = BoundConversion.SynthesizedNonUserDefined(syntax,
operand: BoundCall.Synthesized(syntax,
receiverOpt: null,
method: updateMethod,
arguments: ImmutableArray.Create <BoundExpression>(boundBackingField, boundParameter)),
kind: ConversionKind.ExplicitReference,
type: delegateType);
// _event = (DelegateType)Delegate.Combine(_event, value);
BoundStatement eventUpdate = new BoundExpressionStatement(syntax,
expression: new BoundAssignmentOperator(syntax,
left: boundBackingField,
right: delegateUpdate,
type: delegateType)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
return(new BoundBlock(syntax,
locals: ImmutableArray <LocalSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(
eventUpdate,
@return))
{
WasCompilerGenerated = true
});
}
compareExchangeMethod = compareExchangeMethod.Construct(ImmutableArray.Create <TypeSymbol>(delegateType));
Binder.ReportUseSiteDiagnostics(compareExchangeMethod, diagnostics, syntax);
GeneratedLabelSymbol loopLabel = new GeneratedLabelSymbol("loop");
const int numTemps = 3;
LocalSymbol[] tmps = new LocalSymbol[numTemps];
BoundLocal[] boundTmps = new BoundLocal[numTemps];
for (int i = 0; i < numTemps; i++)
{
tmps[i] = new SynthesizedLocal(accessor, delegateType, SynthesizedLocalKind.LoweringTemp);
boundTmps[i] = new BoundLocal(syntax, tmps[i], null, delegateType);
}
// tmp0 = _event;
BoundStatement tmp0Init = new BoundExpressionStatement(syntax,
expression: new BoundAssignmentOperator(syntax,
left: boundTmps[0],
right: boundBackingField,
type: delegateType)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
// LOOP:
BoundStatement loopStart = new BoundLabelStatement(syntax,
label: loopLabel)
{
WasCompilerGenerated = true
};
// tmp1 = tmp0;
BoundStatement tmp1Update = new BoundExpressionStatement(syntax,
expression: new BoundAssignmentOperator(syntax,
left: boundTmps[1],
right: boundTmps[0],
type: delegateType)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
// (DelegateType)Delegate.Combine(tmp1, value)
delegateUpdate = BoundConversion.SynthesizedNonUserDefined(syntax,
operand: BoundCall.Synthesized(syntax,
receiverOpt: null,
method: updateMethod,
arguments: ImmutableArray.Create <BoundExpression>(boundTmps[1], boundParameter)),
kind: ConversionKind.ExplicitReference,
type: delegateType);
// tmp2 = (DelegateType)Delegate.Combine(tmp1, value);
BoundStatement tmp2Update = new BoundExpressionStatement(syntax,
expression: new BoundAssignmentOperator(syntax,
left: boundTmps[2],
right: delegateUpdate,
type: delegateType)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
// Interlocked.CompareExchange<DelegateType>(ref _event, tmp2, tmp1)
BoundExpression compareExchange = BoundCall.Synthesized(syntax,
receiverOpt: null,
method: compareExchangeMethod,
arguments: ImmutableArray.Create <BoundExpression>(boundBackingField, boundTmps[2], boundTmps[1]));
// tmp0 = Interlocked.CompareExchange<DelegateType>(ref _event, tmp2, tmp1);
BoundStatement tmp0Update = new BoundExpressionStatement(syntax,
expression: new BoundAssignmentOperator(syntax,
left: boundTmps[0],
right: compareExchange,
type: delegateType)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
// tmp0 == tmp1 // i.e. exit when they are equal, jump to start otherwise
BoundExpression loopExitCondition = new BoundBinaryOperator(syntax,
operatorKind: BinaryOperatorKind.ObjectEqual,
left: boundTmps[0],
right: boundTmps[1],
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: boolType)
{
WasCompilerGenerated = true
};
// branchfalse (tmp0 == tmp1) LOOP
BoundStatement loopEnd = new BoundConditionalGoto(syntax,
condition: loopExitCondition,
jumpIfTrue: false,
label: loopLabel)
{
WasCompilerGenerated = true
};
return(new BoundBlock(syntax,
locals: tmps.AsImmutable(),
statements: ImmutableArray.Create <BoundStatement>(
tmp0Init,
loopStart,
tmp1Update,
tmp2Update,
tmp0Update,
loopEnd,
@return))
{
WasCompilerGenerated = true
});
}
internal override BoundExpression GetAddress(BoundPseudoVariable variable)
{
var local = variable.LocalSymbol;
return(InvokeGetMethod(_getAddressMethod.Construct(local.Type), variable.Syntax, local.Name));
}
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);
}
