/// <summary>
/// Perform control flow analysis, reporting all necessary diagnostics. Returns true if the end of
/// the body might be reachable...
/// </summary>
public static bool Analyze(CSharpCompilation compilation, Symbol member, BoundBlock block, DiagnosticBag diagnostics)
{
var walker = new ControlFlowPass(compilation, member, block);
if (diagnostics != null)
{
walker._convertInsufficientExecutionStackExceptionToCancelledByStackGuardException = true;
}
try
{
bool badRegion = false;
var result = walker.Analyze(ref badRegion, diagnostics);
Debug.Assert(!badRegion);
return(result);
}
catch (BoundTreeVisitor.CancelledByStackGuardException ex) when(diagnostics != null)
{
ex.AddAnError(diagnostics);
return(true);
}
finally
{
walker.Free();
}
}
private static bool Analyze(
CSharpCompilation compilation,
MethodSymbol method,
BoundBlock block,
DiagnosticBag diagnostics)
{
var result = ControlFlowPass.Analyze(compilation, method, block, diagnostics);
DataFlowPass.Analyze(compilation, method, block, diagnostics);
return result;
}
private static bool Analyze(
CSharpCompilation compilation,
MethodSymbol method,
BoundBlock block,
DiagnosticBag diagnostics)
{
var result = ControlFlowPass.Analyze(compilation, method, block, diagnostics);
DefiniteAssignmentPass.Analyze(compilation, method, block, diagnostics);
return(result);
}
private static bool Analyze(
CSharpCompilation compilation,
MethodSymbol method,
BoundBlock block,
DiagnosticBag diagnostics,
out bool needsImplicitReturn,
out ImmutableArray <FieldSymbol> implicitlyInitializedFieldsOpt)
{
needsImplicitReturn = ControlFlowPass.Analyze(compilation, method, block, diagnostics);
DefiniteAssignmentPass.Analyze(compilation, method, block, diagnostics, out implicitlyInitializedFieldsOpt, requireOutParamsAssigned: true);
return(needsImplicitReturn || !implicitlyInitializedFieldsOpt.IsDefault);
}
/// <summary>
/// Perform control flow analysis, reporting all necessary diagnostics. Returns true if the end of
/// the body might be reachable..
/// </summary>
public static bool Analyze(CSharpCompilation compilation, Symbol member, BoundNode node, DiagnosticBag diagnostics)
{
var walker = new ControlFlowPass(compilation, member, node);
try
{
bool badRegion = false;
var result = walker.Analyze(ref badRegion, diagnostics);
Debug.Assert(!badRegion);
return(result);
}
finally
{
walker.Free();
}
}
private BoundLambda ReallyBind(NamedTypeSymbol delegateType)
{
var returnType = DelegateReturnType(delegateType);
LambdaSymbol lambdaSymbol;
Binder lambdaBodyBinder;
BoundBlock block;
var diagnostics = DiagnosticBag.GetInstance();
// when binding for real (not for return inference), there is still
// a good chance that we could reuse a body of a lambda previously bound for
// return type inference.
MethodSymbol cacheKey = GetCacheKey(delegateType);
BoundLambda returnInferenceLambda;
if (returnInferenceCache.TryGetValue(cacheKey, out returnInferenceLambda) && returnInferenceLambda.InferredFromSingleType)
{
var lambdaSym = returnInferenceLambda.Symbol;
var lambdaRetType = lambdaSym.ReturnType;
if (lambdaRetType == returnType)
{
lambdaSymbol = lambdaSym;
lambdaBodyBinder = returnInferenceLambda.Binder;
block = returnInferenceLambda.Body;
diagnostics.AddRange(returnInferenceLambda.Diagnostics);
goto haveLambdaBodyAndBinders;
}
}
var parameters = DelegateParameters(delegateType);
lambdaSymbol = new LambdaSymbol(binder.Compilation, binder.ContainingMemberOrLambda, this.unboundLambda, parameters, returnType);
lambdaBodyBinder = new ExecutableCodeBinder(this.unboundLambda.Syntax, lambdaSymbol, ParameterBinder(lambdaSymbol, binder));
block = BindLambdaBody(lambdaSymbol, ref lambdaBodyBinder, diagnostics);
ValidateUnsafeParameters(diagnostics, parameters);
haveLambdaBodyAndBinders:
bool reachableEndpoint = ControlFlowPass.Analyze(binder.Compilation, lambdaSymbol, block, diagnostics);
if (reachableEndpoint)
{
if (DelegateNeedsReturn(delegateType))
{
// Not all code paths return a value in {0} of type '{1}'
diagnostics.Add(ErrorCode.ERR_AnonymousReturnExpected, lambdaSymbol.Locations[0], this.MessageID.Localize(), delegateType);
}
else
{
block = FlowAnalysisPass.AppendImplicitReturn(block, lambdaSymbol, this.unboundLambda.Syntax);
}
}
if (IsAsync && !ErrorFacts.PreventsSuccessfulDelegateConversion(diagnostics))
{
if ((object)returnType != null && // Can be null if "delegateType" is not actually a delegate type.
returnType.SpecialType != SpecialType.System_Void &&
returnType != binder.Compilation.GetWellKnownType(WellKnownType.System_Threading_Tasks_Task) &&
returnType.OriginalDefinition != binder.Compilation.GetWellKnownType(WellKnownType.System_Threading_Tasks_Task_T))
{
// Cannot convert async {0} to delegate type '{1}'. An async {0} may return void, Task or Task<T>, none of which are convertible to '{1}'.
diagnostics.Add(ErrorCode.ERR_CantConvAsyncAnonFuncReturns, lambdaSymbol.Locations[0], lambdaSymbol.MessageID.Localize(), delegateType);
}
}
if (IsAsync)
{
Debug.Assert(lambdaSymbol.IsAsync);
SourceMemberMethodSymbol.ReportAsyncParameterErrors(lambdaSymbol, diagnostics, lambdaSymbol.Locations[0]);
}
var result = new BoundLambda(this.unboundLambda.Syntax, block, diagnostics.ToReadOnlyAndFree(), lambdaBodyBinder, delegateType)
{
WasCompilerGenerated = this.unboundLambda.WasCompilerGenerated
};
return(result);
}
private BoundLambda ReallyBind(NamedTypeSymbol delegateType)
{
var invokeMethod = DelegateInvokeMethod(delegateType);
RefKind refKind;
var returnType = DelegateReturnType(invokeMethod, out refKind);
LambdaSymbol lambdaSymbol;
Binder lambdaBodyBinder;
BoundBlock block;
var diagnostics = DiagnosticBag.GetInstance();
// when binding for real (not for return inference), there is still
// a good chance that we could reuse a body of a lambda previously bound for
// return type inference.
var cacheKey = ReturnInferenceCacheKey.Create(delegateType, IsAsync);
BoundLambda returnInferenceLambda;
if (_returnInferenceCache.TryGetValue(cacheKey, out returnInferenceLambda) && returnInferenceLambda.InferredFromSingleType)
{
lambdaSymbol = returnInferenceLambda.Symbol;
if ((object)LambdaSymbol.InferenceFailureReturnType != lambdaSymbol.ReturnType &&
lambdaSymbol.ReturnType == returnType && lambdaSymbol.RefKind == refKind)
{
lambdaBodyBinder = returnInferenceLambda.Binder;
block = returnInferenceLambda.Body;
diagnostics.AddRange(returnInferenceLambda.Diagnostics);
goto haveLambdaBodyAndBinders;
}
}
lambdaSymbol = new LambdaSymbol(
binder.Compilation,
binder.ContainingMemberOrLambda,
_unboundLambda,
cacheKey.ParameterTypes,
cacheKey.ParameterRefKinds,
refKind,
returnType);
lambdaBodyBinder = new ExecutableCodeBinder(_unboundLambda.Syntax, lambdaSymbol, ParameterBinder(lambdaSymbol, binder));
block = BindLambdaBody(lambdaSymbol, lambdaBodyBinder, diagnostics);
((ExecutableCodeBinder)lambdaBodyBinder).ValidateIteratorMethods(diagnostics);
ValidateUnsafeParameters(diagnostics, cacheKey.ParameterTypes);
haveLambdaBodyAndBinders:
bool reachableEndpoint = ControlFlowPass.Analyze(binder.Compilation, lambdaSymbol, block, diagnostics);
if (reachableEndpoint)
{
if (DelegateNeedsReturn(invokeMethod))
{
// Not all code paths return a value in {0} of type '{1}'
diagnostics.Add(ErrorCode.ERR_AnonymousReturnExpected, lambdaSymbol.DiagnosticLocation, this.MessageID.Localize(), delegateType);
}
else
{
block = FlowAnalysisPass.AppendImplicitReturn(block, lambdaSymbol);
}
}
if (IsAsync && !ErrorFacts.PreventsSuccessfulDelegateConversion(diagnostics))
{
if ((object)returnType != null && // Can be null if "delegateType" is not actually a delegate type.
returnType.SpecialType != SpecialType.System_Void &&
!returnType.IsNonGenericTaskType(binder.Compilation) &&
!returnType.IsGenericTaskType(binder.Compilation))
{
// Cannot convert async {0} to delegate type '{1}'. An async {0} may return void, Task or Task<T>, none of which are convertible to '{1}'.
diagnostics.Add(ErrorCode.ERR_CantConvAsyncAnonFuncReturns, lambdaSymbol.DiagnosticLocation, lambdaSymbol.MessageID.Localize(), delegateType);
}
}
if (IsAsync)
{
Debug.Assert(lambdaSymbol.IsAsync);
SourceMemberMethodSymbol.ReportAsyncParameterErrors(lambdaSymbol.Parameters, diagnostics, lambdaSymbol.DiagnosticLocation);
}
var result = new BoundLambda(_unboundLambda.Syntax, block, diagnostics.ToReadOnlyAndFree(), lambdaBodyBinder, delegateType, inferReturnType: false)
{
WasCompilerGenerated = _unboundLambda.WasCompilerGenerated
};
return(result);
}
private BoundLambda ReallyBind(NamedTypeSymbol delegateType)
{
var invokeMethod = DelegateInvokeMethod(delegateType);
RefKind refKind;
var returnType = DelegateReturnType(invokeMethod, out refKind);
LambdaSymbol lambdaSymbol;
Binder lambdaBodyBinder;
BoundBlock block;
var diagnostics = DiagnosticBag.GetInstance();
// when binding for real (not for return inference), there is still
// a good chance that we could reuse a body of a lambda previously bound for
// return type inference.
MethodSymbol cacheKey = GetCacheKey(delegateType);
BoundLambda returnInferenceLambda;
if (_returnInferenceCache.TryGetValue(cacheKey, out returnInferenceLambda) && returnInferenceLambda.InferredFromSingleType && returnInferenceLambda.Symbol.ReturnType == returnType)
{
lambdaSymbol = returnInferenceLambda.Symbol;
Debug.Assert(lambdaSymbol.RefKind == refKind);
lambdaBodyBinder = returnInferenceLambda.Binder;
block = returnInferenceLambda.Body;
diagnostics.AddRange(returnInferenceLambda.Diagnostics);
goto haveLambdaBodyAndBinders;
}
var parameters = DelegateParameters(invokeMethod);
lambdaSymbol = new LambdaSymbol(
binder.Compilation,
binder.ContainingMemberOrLambda,
_unboundLambda,
parameters,
refKind,
returnType);
lambdaBodyBinder = new ExecutableCodeBinder(_unboundLambda.Syntax, lambdaSymbol, ParameterBinder(lambdaSymbol, binder));
block = BindLambdaBody(lambdaSymbol, lambdaBodyBinder, diagnostics);
((ExecutableCodeBinder)lambdaBodyBinder).ValidateIteratorMethods(diagnostics);
ValidateUnsafeParameters(diagnostics, parameters);
haveLambdaBodyAndBinders:
bool reachableEndpoint = ControlFlowPass.Analyze(binder.Compilation, lambdaSymbol, block, diagnostics);
if (reachableEndpoint)
{
if (DelegateNeedsReturn(invokeMethod))
{
// Not all code paths return a value in {0} of type '{1}'
diagnostics.Add(ErrorCode.ERR_AnonymousReturnExpected, lambdaSymbol.Locations[0], this.MessageID.Localize(), delegateType);
}
else
{
block = FlowAnalysisPass.AppendImplicitReturn(block, lambdaSymbol);
}
}
if (IsAsync && !ErrorFacts.PreventsSuccessfulDelegateConversion(diagnostics))
{
if ((object)returnType != null && // Can be null if "delegateType" is not actually a delegate type.
returnType.SpecialType != SpecialType.System_Void &&
!returnType.IsNonGenericTaskType(binder.Compilation) &&
!returnType.IsGenericTaskType(binder.Compilation))
{
// Cannot convert async {0} to delegate type '{1}'. An async {0} may return void, Task or Task<T>, none of which are convertible to '{1}'.
diagnostics.Add(ErrorCode.ERR_CantConvAsyncAnonFuncReturns, lambdaSymbol.Locations[0], lambdaSymbol.MessageID.Localize(), delegateType);
}
}
if (IsAsync)
{
Debug.Assert(lambdaSymbol.IsAsync);
SourceMemberMethodSymbol.ReportAsyncParameterErrors(lambdaSymbol.Parameters, diagnostics, lambdaSymbol.Locations[0]);
}
// This is an attempt to get a repro for https://devdiv.visualstudio.com/DevDiv/_workitems?id=278481
if ((object)returnType != null && returnType.SpecialType != SpecialType.System_Void &&
!block.HasErrors && !diagnostics.HasAnyResolvedErrors() && block.Statements.Length > 0)
{
BoundStatement first = block.Statements[0];
if (first.Kind == BoundKind.ReturnStatement)
{
var returnStmt = (BoundReturnStatement)first;
if (returnStmt.ExpressionOpt != null && (object)returnStmt.ExpressionOpt.Type == null)
{
throw ExceptionUtilities.Unreachable;
}
}
}
var result = new BoundLambda(_unboundLambda.Syntax, block, diagnostics.ToReadOnlyAndFree(), lambdaBodyBinder, delegateType, inferReturnType: false)
{
WasCompilerGenerated = _unboundLambda.WasCompilerGenerated
};
return(result);
}