internal BoundAwaitableInfo BindAwaitInfo(
BoundAwaitableValuePlaceholder placeholder,
SyntaxNode node,
BindingDiagnosticBag diagnostics,
ref bool hasErrors,
BoundExpression?expressionOpt = null
)
{
bool hasGetAwaitableErrors = !GetAwaitableExpressionInfo(
expressionOpt ?? placeholder,
placeholder,
out bool isDynamic,
out BoundExpression? getAwaiter,
out PropertySymbol? isCompleted,
out MethodSymbol? getResult,
getAwaiterGetResultCall: out _,
node,
diagnostics
);
hasErrors |= hasGetAwaitableErrors;
return(new BoundAwaitableInfo(
node,
placeholder,
isDynamic: isDynamic,
getAwaiter,
isCompleted,
getResult,
hasErrors: hasGetAwaitableErrors
)
{
WasCompilerGenerated = true
});
}
private BoundAwaitExpression BindAwait(
BoundExpression expression,
SyntaxNode node,
BindingDiagnosticBag diagnostics
)
{
bool hasErrors = false;
var placeholder = new BoundAwaitableValuePlaceholder(
expression.Syntax,
GetValEscape(expression, LocalScopeDepth),
expression.Type
);
ReportBadAwaitDiagnostics(node, node.Location, diagnostics, ref hasErrors);
var info = BindAwaitInfo(
placeholder,
node,
diagnostics,
ref hasErrors,
expressionOpt: expression
);
// Spec 7.7.7.2:
// The expression await t is classified the same way as the expression (t).GetAwaiter().GetResult(). Thus,
// if the return type of GetResult is void, the await-expression is classified as nothing. If it has a
// non-void return type T, the await-expression is classified as a value of type T.
TypeSymbol awaitExpressionType =
info.GetResult?.ReturnType
?? (hasErrors ? CreateErrorType() : Compilation.DynamicType);
return(new BoundAwaitExpression(node, expression, info, awaitExpressionType, hasErrors));
}
internal static BoundStatement BindUsingStatementOrDeclarationFromParts(SyntaxNode syntax, SyntaxToken usingKeyword, SyntaxToken awaitKeyword, Binder originalBinder, UsingStatementBinder usingBinderOpt, DiagnosticBag diagnostics)
{
bool isUsingDeclaration = syntax.Kind() == SyntaxKind.LocalDeclarationStatement;
bool isExpression = !isUsingDeclaration && syntax.Kind() != SyntaxKind.VariableDeclaration;
bool hasAwait = awaitKeyword != default;
Debug.Assert(isUsingDeclaration || usingBinderOpt != null);
TypeSymbol disposableInterface = getDisposableInterface(hasAwait);
Debug.Assert((object)disposableInterface != null);
bool hasErrors = ReportUseSiteDiagnostics(disposableInterface, diagnostics, hasAwait ? awaitKeyword : usingKeyword);
Conversion iDisposableConversion = Conversion.NoConversion;
ImmutableArray <BoundLocalDeclaration> declarationsOpt = default;
BoundMultipleLocalDeclarations multipleDeclarationsOpt = null;
BoundExpression expressionOpt = null;
AwaitableInfo awaitOpt = null;
TypeSymbol declarationTypeOpt = null;
MethodSymbol disposeMethodOpt = null;
TypeSymbol awaitableTypeOpt = null;
if (isExpression)
{
expressionOpt = usingBinderOpt.BindTargetExpression(diagnostics, originalBinder);
hasErrors |= !populateDisposableConversionOrDisposeMethod(fromExpression: true);
}
else
{
VariableDeclarationSyntax declarationSyntax = isUsingDeclaration ? ((LocalDeclarationStatementSyntax)syntax).Declaration : (VariableDeclarationSyntax)syntax;
originalBinder.BindForOrUsingOrFixedDeclarations(declarationSyntax, LocalDeclarationKind.UsingVariable, diagnostics, out declarationsOpt);
Debug.Assert(!declarationsOpt.IsEmpty);
multipleDeclarationsOpt = new BoundMultipleLocalDeclarations(declarationSyntax, declarationsOpt);
declarationTypeOpt = declarationsOpt[0].DeclaredType.Type;
if (declarationTypeOpt.IsDynamic())
{
iDisposableConversion = Conversion.ImplicitDynamic;
}
else
{
hasErrors |= !populateDisposableConversionOrDisposeMethod(fromExpression: false);
}
}
if (hasAwait)
{
BoundAwaitableValuePlaceholder placeholderOpt;
if (awaitableTypeOpt is null)
{
placeholderOpt = null;
}
else
{
hasErrors |= ReportUseSiteDiagnostics(awaitableTypeOpt, diagnostics, awaitKeyword);
placeholderOpt = new BoundAwaitableValuePlaceholder(syntax, awaitableTypeOpt).MakeCompilerGenerated();
}
// even if we don't have a proper value to await, we'll still report bad usages of `await`
awaitOpt = originalBinder.BindAwaitInfo(placeholderOpt, syntax, awaitKeyword.GetLocation(), diagnostics, ref hasErrors);
}
// This is not awesome, but its factored.
// In the future it might be better to have a seperate shared type that we add the info to, and have the callers create the appropriate bound nodes from it
if (isUsingDeclaration)
{
return(new BoundUsingLocalDeclarations(syntax, disposeMethodOpt, iDisposableConversion, awaitOpt, declarationsOpt, hasErrors));
}
else
{
BoundStatement boundBody = originalBinder.BindPossibleEmbeddedStatement(usingBinderOpt._syntax.Statement, diagnostics);
return(new BoundUsingStatement(
usingBinderOpt._syntax,
usingBinderOpt.Locals,
multipleDeclarationsOpt,
expressionOpt,
iDisposableConversion,
boundBody,
awaitOpt,
disposeMethodOpt,
hasErrors));
}
// initializes iDisposableConversion, awaitableTypeOpt and disposeMethodOpt
bool populateDisposableConversionOrDisposeMethod(bool fromExpression)
{
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
iDisposableConversion = classifyConversion(fromExpression, disposableInterface, ref useSiteDiagnostics);
diagnostics.Add(syntax, useSiteDiagnostics);
if (iDisposableConversion.IsImplicit)
{
if (hasAwait)
{
awaitableTypeOpt = originalBinder.Compilation.GetWellKnownType(WellKnownType.System_Threading_Tasks_ValueTask);
}
return(true);
}
TypeSymbol type = fromExpression ? expressionOpt.Type : declarationTypeOpt;
// If this is a ref struct, or we're in a valid asynchronous using, try binding via pattern.
// We won't need to try and bind a second time if it fails, as async dispose can't be pattern based (ref structs are not allowed in async methods)
if (!(type is null) && (type.IsRefLikeType || hasAwait))
{
BoundExpression receiver = fromExpression
? expressionOpt
: new BoundLocal(syntax, declarationsOpt[0].LocalSymbol, null, type)
{
WasCompilerGenerated = true
};
disposeMethodOpt = originalBinder.TryFindDisposePatternMethod(receiver, syntax, hasAwait, diagnostics);
if (!(disposeMethodOpt is null))
{
if (hasAwait)
{
awaitableTypeOpt = disposeMethodOpt.ReturnType;
}
return(true);
}
}
if (type is null || !type.IsErrorType())
{
// Retry with a different assumption about whether the `using` is async
TypeSymbol alternateInterface = getDisposableInterface(!hasAwait);
HashSet <DiagnosticInfo> ignored = null;
Conversion alternateConversion = classifyConversion(fromExpression, alternateInterface, ref ignored);
bool wrongAsync = alternateConversion.IsImplicit;
ErrorCode errorCode = wrongAsync
? (hasAwait ? ErrorCode.ERR_NoConvToIAsyncDispWrongAsync : ErrorCode.ERR_NoConvToIDispWrongAsync)
: (hasAwait ? ErrorCode.ERR_NoConvToIAsyncDisp : ErrorCode.ERR_NoConvToIDisp);
Error(diagnostics, errorCode, syntax, declarationTypeOpt ?? expressionOpt.Display);
}
return(false);
}
Conversion classifyConversion(bool fromExpression, TypeSymbol targetInterface, ref HashSet <DiagnosticInfo> diag)
{
return(fromExpression ?
originalBinder.Conversions.ClassifyImplicitConversionFromExpression(expressionOpt, targetInterface, ref diag) :
originalBinder.Conversions.ClassifyImplicitConversionFromType(declarationTypeOpt, targetInterface, ref diag));
}
TypeSymbol getDisposableInterface(bool isAsync)
{
return(isAsync
? originalBinder.Compilation.GetWellKnownType(WellKnownType.System_IAsyncDisposable)
: originalBinder.Compilation.GetSpecialType(SpecialType.System_IDisposable));
}
}
internal override BoundStatement BindUsingStatementParts(DiagnosticBag diagnostics, Binder originalBinder)
{
ExpressionSyntax expressionSyntax = TargetExpressionSyntax;
VariableDeclarationSyntax declarationSyntax = _syntax.Declaration;
bool hasAwait = _syntax.AwaitKeyword.Kind() != default;
Debug.Assert((expressionSyntax == null) ^ (declarationSyntax == null)); // Can't have both or neither.
TypeSymbol iDisposable = hasAwait
? this.Compilation.GetWellKnownType(WellKnownType.System_IAsyncDisposable)
: this.Compilation.GetSpecialType(SpecialType.System_IDisposable);
Debug.Assert((object)iDisposable != null);
bool hasErrors = ReportUseSiteDiagnostics(iDisposable, diagnostics, hasAwait ? _syntax.AwaitKeyword : _syntax.UsingKeyword);
Conversion iDisposableConversion = Conversion.NoConversion;
BoundMultipleLocalDeclarations declarationsOpt = null;
BoundExpression expressionOpt = null;
AwaitableInfo awaitOpt = null;
if (expressionSyntax != null)
{
expressionOpt = this.BindTargetExpression(diagnostics, originalBinder);
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
iDisposableConversion = originalBinder.Conversions.ClassifyImplicitConversionFromExpression(expressionOpt, iDisposable, ref useSiteDiagnostics);
diagnostics.Add(expressionSyntax, useSiteDiagnostics);
if (!iDisposableConversion.IsImplicit)
{
TypeSymbol expressionType = expressionOpt.Type;
if ((object)expressionType == null || !expressionType.IsErrorType())
{
Error(diagnostics, hasAwait ? ErrorCode.ERR_NoConvToIAsyncDisp : ErrorCode.ERR_NoConvToIDisp, expressionSyntax, expressionOpt.Display);
}
hasErrors = true;
}
}
else
{
ImmutableArray <BoundLocalDeclaration> declarations;
originalBinder.BindForOrUsingOrFixedDeclarations(declarationSyntax, LocalDeclarationKind.UsingVariable, diagnostics, out declarations);
Debug.Assert(!declarations.IsEmpty);
declarationsOpt = new BoundMultipleLocalDeclarations(declarationSyntax, declarations);
TypeSymbol declType = declarations[0].DeclaredType.Type;
if (declType.IsDynamic())
{
iDisposableConversion = Conversion.ImplicitDynamic;
}
else
{
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
iDisposableConversion = originalBinder.Conversions.ClassifyImplicitConversionFromType(declType, iDisposable, ref useSiteDiagnostics);
diagnostics.Add(declarationSyntax, useSiteDiagnostics);
if (!iDisposableConversion.IsImplicit)
{
if (!declType.IsErrorType())
{
Error(diagnostics, hasAwait ? ErrorCode.ERR_NoConvToIAsyncDisp : ErrorCode.ERR_NoConvToIDisp, declarationSyntax, declType);
}
hasErrors = true;
}
}
}
if (hasAwait)
{
TypeSymbol taskType = this.Compilation.GetWellKnownType(WellKnownType.System_Threading_Tasks_ValueTask);
hasErrors |= ReportUseSiteDiagnostics(taskType, diagnostics, _syntax.AwaitKeyword);
var resource = (SyntaxNode)expressionSyntax ?? declarationSyntax;
BoundExpression placeholder = new BoundAwaitableValuePlaceholder(resource, taskType).MakeCompilerGenerated();
awaitOpt = BindAwaitInfo(placeholder, resource, _syntax.AwaitKeyword.GetLocation(), diagnostics, ref hasErrors);
}
BoundStatement boundBody = originalBinder.BindPossibleEmbeddedStatement(_syntax.Statement, diagnostics);
Debug.Assert(GetDeclaredLocalsForScope(_syntax) == this.Locals);
return(new BoundUsingStatement(
_syntax,
this.Locals,
declarationsOpt,
expressionOpt,
iDisposableConversion,
boundBody,
awaitOpt,
hasErrors));
}
public override BoundNode VisitAwaitableValuePlaceholder(BoundAwaitableValuePlaceholder node)
{
return(_placeholderMap[node]);
}
public override BoundNode VisitAwaitableValuePlaceholder(BoundAwaitableValuePlaceholder node)
{
Fail(node);
return(null);
}
internal override BoundStatement BindUsingStatementParts(DiagnosticBag diagnostics, Binder originalBinder)
{
ExpressionSyntax expressionSyntax = TargetExpressionSyntax;
VariableDeclarationSyntax declarationSyntax = _syntax.Declaration;
bool hasAwait = _syntax.AwaitKeyword.Kind() != default;
Debug.Assert((expressionSyntax == null) ^ (declarationSyntax == null)); // Can't have both or neither.
TypeSymbol disposableInterface = getDisposableInterface(hasAwait);
Debug.Assert((object)disposableInterface != null);
bool hasErrors = ReportUseSiteDiagnostics(disposableInterface, diagnostics, hasAwait ? _syntax.AwaitKeyword : _syntax.UsingKeyword);
Conversion iDisposableConversion = Conversion.NoConversion;
BoundMultipleLocalDeclarations declarationsOpt = null;
BoundExpression expressionOpt = null;
AwaitableInfo awaitOpt = null;
TypeSymbol declarationTypeOpt = null;
if (expressionSyntax != null)
{
expressionOpt = this.BindTargetExpression(diagnostics, originalBinder);
hasErrors |= !initConversion(fromExpression: true);
}
else
{
ImmutableArray <BoundLocalDeclaration> declarations;
originalBinder.BindForOrUsingOrFixedDeclarations(declarationSyntax, LocalDeclarationKind.UsingVariable, diagnostics, out declarations);
Debug.Assert(!declarations.IsEmpty);
declarationsOpt = new BoundMultipleLocalDeclarations(declarationSyntax, declarations);
declarationTypeOpt = declarations[0].DeclaredType.Type;
if (declarationTypeOpt.IsDynamic())
{
iDisposableConversion = Conversion.ImplicitDynamic;
}
else
{
hasErrors |= !initConversion(fromExpression: false);
}
}
if (hasAwait)
{
TypeSymbol taskType = this.Compilation.GetWellKnownType(WellKnownType.System_Threading_Tasks_ValueTask);
hasErrors |= ReportUseSiteDiagnostics(taskType, diagnostics, _syntax.AwaitKeyword);
var resource = (SyntaxNode)expressionSyntax ?? declarationSyntax;
BoundExpression placeholder = new BoundAwaitableValuePlaceholder(resource, taskType).MakeCompilerGenerated();
awaitOpt = BindAwaitInfo(placeholder, resource, _syntax.AwaitKeyword.GetLocation(), diagnostics, ref hasErrors);
}
BoundStatement boundBody = originalBinder.BindPossibleEmbeddedStatement(_syntax.Statement, diagnostics);
Debug.Assert(GetDeclaredLocalsForScope(_syntax) == this.Locals);
return(new BoundUsingStatement(
_syntax,
this.Locals,
declarationsOpt,
expressionOpt,
iDisposableConversion,
boundBody,
awaitOpt,
hasErrors));
bool initConversion(bool fromExpression)
{
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
iDisposableConversion = classifyConversion(fromExpression, disposableInterface, ref useSiteDiagnostics);
diagnostics.Add(fromExpression ? (CSharpSyntaxNode)expressionSyntax : declarationSyntax, useSiteDiagnostics);
if (iDisposableConversion.IsImplicit)
{
return(true);
}
TypeSymbol type = fromExpression ? expressionOpt.Type : declarationTypeOpt;
if (type is null || !type.IsErrorType())
{
// Retry with a different assumption about whether the `using` is async
TypeSymbol alternateInterface = getDisposableInterface(!hasAwait);
HashSet <DiagnosticInfo> ignored = null;
Conversion alternateConversion = classifyConversion(fromExpression, alternateInterface, ref ignored);
bool wrongAsync = alternateConversion.IsImplicit;
ErrorCode errorCode = wrongAsync
? (hasAwait ? ErrorCode.ERR_NoConvToIAsyncDispWrongAsync : ErrorCode.ERR_NoConvToIDispWrongAsync)
: (hasAwait ? ErrorCode.ERR_NoConvToIAsyncDisp : ErrorCode.ERR_NoConvToIDisp);
Error(diagnostics, errorCode, (CSharpSyntaxNode)declarationSyntax ?? expressionSyntax, declarationTypeOpt ?? expressionOpt.Display);
}
return(false);
}
Conversion classifyConversion(bool fromExpression, TypeSymbol targetInterface, ref HashSet <DiagnosticInfo> diag)
{
return(fromExpression ?
originalBinder.Conversions.ClassifyImplicitConversionFromExpression(expressionOpt, targetInterface, ref diag) :
originalBinder.Conversions.ClassifyImplicitConversionFromType(declarationTypeOpt, targetInterface, ref diag));
}
TypeSymbol getDisposableInterface(bool isAsync)
{
return(isAsync
? this.Compilation.GetWellKnownType(WellKnownType.System_IAsyncDisposable)
: this.Compilation.GetSpecialType(SpecialType.System_IDisposable));
}
}