// All nodes with a single child expression are rewritten in the same manner.
//
// If the node is an expression and the child contains an await expression, then the rewriting transforms:
// Expression(Spill(sideEffects, Value))
// to:
// Spill(sideEffects, Expression(Value))
//
// If the node is a statement and the child contains an await expression, then the rewriting transforms:
// ExpressionStatement(Spill(sideEffects, Value))
// to:
// Block(sideEffects, ExpressionStatement(Value))
//
// If the child expression does not contain an await expression then no rewriting is performed.
public override BoundNode VisitExpressionStatement(BoundExpressionStatement node)
{
BoundExpression expression = (BoundExpression)this.Visit(node.Expression);
if (expression.Kind != BoundKind.SpillSequence)
{
return node.Update(expression);
}
return RewriteSpillSequenceAsBlock((BoundSpillSequence)expression);
}
private BoundStatement RewriteLocalDeclaration(BoundLocalDeclaration originalOpt, SyntaxNode syntax, LocalSymbol localSymbol, BoundExpression rewrittenInitializer, bool hasErrors = false)
{
// A declaration of a local variable without an initializer has no associated IL.
// Simply remove the declaration from the bound tree. The local symbol will
// remain in the bound block, so codegen will make a stack frame location for it.
if (rewrittenInitializer == null)
{
return null;
}
// A declaration of a local constant also does nothing, even though there is
// an assignment. The value will be emitted directly where it is used. The
// local symbol remains in the bound block, but codegen will skip making a
// stack frame location for it. (We still need a symbol for it to stay
// around because we'll be generating debug info for it.)
if (localSymbol.IsConst)
{
if (!localSymbol.Type.IsReferenceType && localSymbol.ConstantValue == null)
{
// This can occur in error scenarios (e.g. bad imported metadata)
hasErrors = true;
}
else
{
return null;
}
}
// lowered local declaration node is associated with declaration (not whole statement)
// this is done to make sure that debugger stepping is same as before
var localDeclaration = syntax as LocalDeclarationStatementSyntax;
if (localDeclaration != null)
{
syntax = localDeclaration.Declaration.Variables[0];
}
BoundStatement rewrittenLocalDeclaration = new BoundExpressionStatement(
syntax,
new BoundAssignmentOperator(
syntax,
new BoundLocal(
syntax,
localSymbol,
null,
localSymbol.Type
),
rewrittenInitializer,
localSymbol.Type,
localSymbol.RefKind),
hasErrors);
return InstrumentLocalDeclarationIfNecessary(originalOpt, localSymbol, rewrittenLocalDeclaration);
}
internal static ImmutableArray<BoundStatement> ConstructScriptConstructorBody(
BoundStatement loweredBody,
MethodSymbol constructor,
SynthesizedSubmissionFields previousSubmissionFields,
CSharpCompilation compilation)
{
// Script field initializers have to be emitted after the call to the base constructor because they can refer to "this" instance.
//
// Unlike regular field initializers, initializers of global script variables can access "this" instance.
// If the base class had a constructor that initializes its state a global variable would access partially initialized object.
// For this reason Script class must always derive directly from a class that has no state (System.Object).
CSharpSyntaxNode syntax = loweredBody.Syntax;
// base constructor call:
Debug.Assert((object)constructor.ContainingType.BaseTypeNoUseSiteDiagnostics == null || constructor.ContainingType.BaseTypeNoUseSiteDiagnostics.SpecialType == SpecialType.System_Object);
var objectType = constructor.ContainingAssembly.GetSpecialType(SpecialType.System_Object);
BoundExpression receiver = new BoundThisReference(syntax, constructor.ContainingType) { WasCompilerGenerated = true };
BoundStatement baseConstructorCall =
new BoundExpressionStatement(syntax,
new BoundCall(syntax,
receiverOpt: receiver,
method: objectType.InstanceConstructors[0],
arguments: ImmutableArray<BoundExpression>.Empty,
argumentNamesOpt: ImmutableArray<string>.Empty,
argumentRefKindsOpt: ImmutableArray<RefKind>.Empty,
isDelegateCall: false,
expanded: false,
invokedAsExtensionMethod: false,
argsToParamsOpt: ImmutableArray<int>.Empty,
resultKind: LookupResultKind.Viable,
type: objectType)
{ WasCompilerGenerated = true })
{ WasCompilerGenerated = true };
var statements = ArrayBuilder<BoundStatement>.GetInstance();
statements.Add(baseConstructorCall);
if (constructor.IsSubmissionConstructor)
{
// submission initialization:
MakeSubmissionInitialization(statements, syntax, constructor, previousSubmissionFields, compilation);
}
statements.Add(loweredBody);
return statements.ToImmutableAndFree();
}
public override BoundNode VisitExpressionStatement(BoundExpressionStatement node)
{
var syntax = node.Syntax;
var loweredExpression = VisitUnusedExpression(node.Expression);
if (loweredExpression == null)
{
// NOTE: not using a BoundNoOpStatement, since we don't want a nop to be emitted.
// CONSIDER: could use a BoundNoOpStatement (DevDiv #12943).
return BoundStatementList.Synthesized(syntax);
}
else
{
return AddSequencePoint(node.Update(loweredExpression));
}
}
public override BoundStatement InstrumentFieldOrPropertyInitializer(BoundExpressionStatement original, BoundStatement rewritten)
{
rewritten = base.InstrumentExpressionStatement(original, rewritten);
CSharpSyntaxNode syntax = original.Syntax;
switch (syntax.Parent.Parent.Kind())
{
case SyntaxKind.VariableDeclarator:
var declaratorSyntax = (VariableDeclaratorSyntax)syntax.Parent.Parent;
return AddSequencePoint(declaratorSyntax, rewritten);
case SyntaxKind.PropertyDeclaration:
var declaration = (PropertyDeclarationSyntax)syntax.Parent.Parent;
return AddSequencePoint(declaration, rewritten);
default:
throw ExceptionUtilities.UnexpectedValue(syntax.Parent.Parent.Kind());
}
}
private BoundStatement RewriteExpressionStatement(BoundExpressionStatement node, bool suppressInstrumentation = false)
{
var loweredExpression = VisitUnusedExpression(node.Expression);
if (loweredExpression == null)
{
return null;
}
else
{
BoundStatement result = node.Update(loweredExpression);
if (!suppressInstrumentation && this.Instrument && !node.WasCompilerGenerated)
{
result = _instrumenter.InstrumentExpressionStatement(node, result);
}
return result;
}
}
public override BoundStatement InstrumentExpressionStatement(BoundExpressionStatement original, BoundStatement rewritten)
{
rewritten = base.InstrumentExpressionStatement(original, rewritten);
if (original.IsConstructorInitializer())
{
switch (original.Syntax.Kind())
{
case SyntaxKind.ConstructorDeclaration:
// This is an implicit constructor initializer.
var decl = (ConstructorDeclarationSyntax)original.Syntax;
return new BoundSequencePointWithSpan(decl, rewritten, CreateSpanForConstructorInitializer(decl));
case SyntaxKind.BaseConstructorInitializer:
case SyntaxKind.ThisConstructorInitializer:
var init = (ConstructorInitializerSyntax)original.Syntax;
return new BoundSequencePointWithSpan(init, rewritten, CreateSpanForConstructorInitializer((ConstructorDeclarationSyntax)init.Parent));
}
}
return AddSequencePoint(rewritten);
}
public override BoundNode VisitLocalDeconstructionDeclaration(BoundLocalDeconstructionDeclaration node)
{
var syntax = node.Syntax;
var loweredExpression = VisitUnusedExpression(node.Assignment);
if (loweredExpression == null)
{
// NOTE: not using a BoundNoOpStatement, since we don't want a nop to be emitted.
// CONSIDER: could use a BoundNoOpStatement (DevDiv #12943).
return BoundStatementList.Synthesized(syntax);
}
else
{
BoundStatement result = new BoundExpressionStatement(loweredExpression.Syntax, loweredExpression, node.HasErrors);
result.WasCompilerGenerated = node.WasCompilerGenerated;
if (this.Instrument && !node.WasCompilerGenerated)
{
result = _instrumenter.InstrumentLocalDeconstructionDeclaration(node, result);
}
return result;
}
}
private static BoundInitializer BindGlobalStatement(
Binder binder,
SynthesizedInteractiveInitializerMethod scriptInitializer,
StatementSyntax statementNode,
DiagnosticBag diagnostics,
bool isLast)
{
var statement = binder.BindStatement(statementNode, diagnostics);
if (isLast && !statement.HasAnyErrors)
{
// the result of the last global expression is assigned to the result storage for submission result:
if (binder.Compilation.IsSubmission)
{
// insert an implicit conversion for the submission return type (if needed):
var expression = InitializerRewriter.GetTrailingScriptExpression(statement);
if (expression != null &&
((object)expression.Type == null || expression.Type.SpecialType != SpecialType.System_Void))
{
var submissionResultType = scriptInitializer.ResultType;
expression = binder.GenerateConversionForAssignment(submissionResultType, expression, diagnostics);
statement = new BoundExpressionStatement(statement.Syntax, expression, expression.HasErrors);
}
}
// don't allow trailing expressions after labels (as in regular C#, labels must be followed by a statement):
if (statement.Kind == BoundKind.LabeledStatement)
{
var labeledStatementBody = ((BoundLabeledStatement)statement).Body;
while (labeledStatementBody.Kind == BoundKind.LabeledStatement)
{
labeledStatementBody = ((BoundLabeledStatement)labeledStatementBody).Body;
}
if (InitializerRewriter.GetTrailingScriptExpression(labeledStatementBody) != null)
{
Error(diagnostics, ErrorCode.ERR_SemicolonExpected, ((ExpressionStatementSyntax)labeledStatementBody.Syntax).SemicolonToken);
}
}
}
return new BoundGlobalStatementInitializer(statementNode, statement);
}
public override BoundStatement InstrumentFieldOrPropertyInitializer(BoundExpressionStatement original, BoundStatement rewritten)
{
return Previous.InstrumentFieldOrPropertyInitializer(original, rewritten);
}
public override BoundNode VisitExpressionStatement(BoundExpressionStatement node)
{
if (node.Expression.Kind == BoundKind.AwaitExpression)
{
return VisitAwaitExpression((BoundAwaitExpression)node.Expression, resultPlace: null);
}
else if (node.Expression.Kind == BoundKind.AssignmentOperator)
{
var expression = (BoundAssignmentOperator)node.Expression;
if (expression.Right.Kind == BoundKind.AwaitExpression)
{
return VisitAwaitExpression((BoundAwaitExpression)expression.Right, resultPlace: expression.Left);
}
}
BoundExpression expr = (BoundExpression)this.Visit(node.Expression);
return (expr != null) ? node.Update(expr) : (BoundStatement)F.Block();
}
public override BoundNode VisitExpressionStatement(BoundExpressionStatement node)
{
// expressions cannot contain labels, branches or yields.
return(null);
}
/// <summary>
/// Generates a submission initialization part of a Script type constructor that represents an interactive submission.
/// </summary>
/// <remarks>
/// The constructor takes a parameter of type Roslyn.Scripting.Session - the session reference.
/// It adds the object being constructed into the session by calling Microsoft.CSharp.RuntimeHelpers.SessionHelpers.SetSubmission,
/// and retrieves strongly typed references on all previous submission script classes whose members are referenced by this submission.
/// The references are stored to fields of the submission (<paramref name="synthesizedFields"/>).
/// </remarks>
private static ImmutableArray<BoundStatement> MakeSubmissionInitialization(CSharpSyntaxNode syntax, MethodSymbol submissionConstructor, SynthesizedSubmissionFields synthesizedFields, CSharpCompilation compilation)
{
Debug.Assert(submissionConstructor.ParameterCount == 2);
BoundStatement[] result = new BoundStatement[1 + synthesizedFields.Count];
var sessionReference = new BoundParameter(syntax, submissionConstructor.Parameters[0]) { WasCompilerGenerated = true };
var submissionGetter = (MethodSymbol)compilation.GetWellKnownTypeMember(
WellKnownMember.Microsoft_CSharp_RuntimeHelpers_SessionHelpers__GetSubmission
);
var submissionAdder = (MethodSymbol)compilation.GetWellKnownTypeMember(
WellKnownMember.Microsoft_CSharp_RuntimeHelpers_SessionHelpers__SetSubmission
);
// TODO: report missing adder/getter
Debug.Assert((object)submissionAdder != null && (object)submissionGetter != null);
var intType = compilation.GetSpecialType(SpecialType.System_Int32);
var thisReference = new BoundThisReference(syntax, submissionConstructor.ContainingType) { WasCompilerGenerated = true };
int i = 0;
// hostObject = (THostObject)SessionHelpers.SetSubmission(<session>, <slot index>, this);
var slotIndex = compilation.GetSubmissionSlotIndex();
Debug.Assert(slotIndex >= 0);
BoundExpression setSubmission = BoundCall.Synthesized(syntax,
null,
submissionAdder,
sessionReference,
new BoundLiteral(syntax, ConstantValue.Create(slotIndex), intType) { WasCompilerGenerated = true },
thisReference
);
var hostObjectField = synthesizedFields.GetHostObjectField();
if ((object)hostObjectField != null)
{
setSubmission = new BoundAssignmentOperator(syntax,
new BoundFieldAccess(syntax, thisReference, hostObjectField, ConstantValue.NotAvailable) { WasCompilerGenerated = true },
BoundConversion.Synthesized(syntax,
setSubmission,
Conversion.ExplicitReference,
false,
true,
ConstantValue.NotAvailable,
hostObjectField.Type
),
hostObjectField.Type
)
{ WasCompilerGenerated = true };
}
result[i++] = new BoundExpressionStatement(syntax, setSubmission) { WasCompilerGenerated = true };
foreach (var field in synthesizedFields.FieldSymbols)
{
var targetScriptClass = (ImplicitNamedTypeSymbol)field.Type;
var targetSubmissionId = targetScriptClass.DeclaringCompilation.GetSubmissionSlotIndex();
Debug.Assert(targetSubmissionId >= 0);
// this.<field> = (<FieldType>)SessionHelpers.GetSubmission(<session>, <i>);
result[i++] =
new BoundExpressionStatement(syntax,
new BoundAssignmentOperator(syntax,
new BoundFieldAccess(syntax, thisReference, field, ConstantValue.NotAvailable) { WasCompilerGenerated = true },
BoundConversion.Synthesized(syntax,
BoundCall.Synthesized(syntax,
null,
submissionGetter,
sessionReference,
new BoundLiteral(syntax, ConstantValue.Create(targetSubmissionId), intType) { WasCompilerGenerated = true }),
Conversion.ExplicitReference,
false,
true,
ConstantValue.NotAvailable,
targetScriptClass
),
targetScriptClass
)
{ WasCompilerGenerated = true })
{ WasCompilerGenerated = true };
}
Debug.Assert(i == result.Length);
return result.AsImmutableOrNull();
}
/// <summary>
/// Wrap a given expression e into a block as either { e; } or { return e; }
/// Shared between lambda and expression-bodied method binding.
/// </summary>
internal BoundBlock CreateBlockFromExpression(CSharpSyntaxNode node, ImmutableArray<LocalSymbol> locals, ExpressionSyntax expressionSyntax, BoundExpression expression, DiagnosticBag diagnostics)
{
var returnType = GetCurrentReturnType();
var syntax = expressionSyntax ?? expression.Syntax;
BoundStatement statement;
if ((object)returnType != null)
{
if (returnType.SpecialType == SpecialType.System_Void || IsTaskReturningAsyncMethod())
{
// If the return type is void then the expression is required to be a legal
// statement expression.
Debug.Assert(expressionSyntax != null || !IsValidStatementExpression(expression.Syntax, expression));
bool errors = false;
if (expressionSyntax == null || !IsValidStatementExpression(expressionSyntax, expression))
{
Error(diagnostics, ErrorCode.ERR_IllegalStatement, syntax);
errors = true;
}
// Don't mark compiler generated so that the rewriter generates sequence points
var expressionStatement = new BoundExpressionStatement(syntax, expression, errors);
CheckForUnobservedAwaitable(expressionStatement, diagnostics);
statement = expressionStatement;
}
else
{
expression = CreateReturnConversion(syntax, diagnostics, expression, returnType);
statement = new BoundReturnStatement(syntax, expression) { WasCompilerGenerated = true };
}
}
else if (expression.Type?.SpecialType == SpecialType.System_Void)
{
statement = new BoundExpressionStatement(syntax, expression) { WasCompilerGenerated = true };
}
else
{
statement = new BoundReturnStatement(syntax, expression) { WasCompilerGenerated = true };
}
// Need to attach the tree for when we generate sequence points.
return new BoundBlock(node, locals, ImmutableArray.Create(statement)) { WasCompilerGenerated = node.Kind() != SyntaxKind.ArrowExpressionClause };
}
public virtual BoundStatement InstrumentFieldOrPropertyInitializer(BoundExpressionStatement original, BoundStatement rewritten)
{
Debug.Assert(LocalRewriter.IsFieldOrPropertyInitializer(original));
return(InstrumentStatement(original, rewritten));
}
private BoundStatement MakeSwitchStatementWithNullableExpression(
SyntaxNode syntax,
BoundExpression rewrittenExpression,
ImmutableArray <BoundSwitchSection> rewrittenSections,
LabelSymbol constantTargetOpt,
ImmutableArray <LocalSymbol> locals,
ImmutableArray <LocalFunctionSymbol> localFunctions,
GeneratedLabelSymbol breakLabel,
BoundSwitchStatement oldNode)
{
Debug.Assert(rewrittenExpression.Type.IsNullableType());
var exprSyntax = rewrittenExpression.Syntax;
var exprNullableType = rewrittenExpression.Type;
var statementBuilder = ArrayBuilder <BoundStatement> .GetInstance();
// Rewrite the nullable expression to a temp as we might have a user defined conversion from source expression to switch governing type.
// We can avoid generating the temp if the expression is a bound local.
LocalSymbol tempLocal;
if (rewrittenExpression.Kind != BoundKind.Local)
{
BoundAssignmentOperator assignmentToTemp;
BoundLocal boundTemp = _factory.StoreToTemp(rewrittenExpression, out assignmentToTemp);
var tempAssignment = new BoundExpressionStatement(exprSyntax, assignmentToTemp);
statementBuilder.Add(tempAssignment);
tempLocal = boundTemp.LocalSymbol;
rewrittenExpression = boundTemp;
}
else
{
tempLocal = null;
}
// Generate a BoundConditionalGoto with null check as the conditional expression and appropriate switch label as the target: null, default or exit label.
BoundStatement condGotoNullValueTargetLabel = new BoundConditionalGoto(
exprSyntax,
condition: MakeNullCheck(exprSyntax, rewrittenExpression, BinaryOperatorKind.NullableNullEqual),
jumpIfTrue: true,
label: GetNullValueTargetSwitchLabel(rewrittenSections, breakLabel));
// Rewrite the switch statement using nullable expression's underlying value as the switch expression.
// rewrittenExpression.GetValueOrDefault()
MethodSymbol getValueOrDefault = UnsafeGetNullableMethod(syntax, exprNullableType, SpecialMember.System_Nullable_T_GetValueOrDefault);
BoundCall callGetValueOrDefault = BoundCall.Synthesized(exprSyntax, rewrittenExpression, getValueOrDefault);
rewrittenExpression = callGetValueOrDefault;
// rewrite switch statement
BoundStatement rewrittenSwitchStatement = MakeSwitchStatementWithNonNullableExpression(
syntax,
condGotoNullValueTargetLabel,
rewrittenExpression,
rewrittenSections,
constantTargetOpt,
locals,
localFunctions,
breakLabel,
oldNode);
statementBuilder.Add(rewrittenSwitchStatement);
return(new BoundBlock(
syntax,
locals: (object)tempLocal == null ? ImmutableArray <LocalSymbol> .Empty : ImmutableArray.Create <LocalSymbol>(tempLocal),
statements: statementBuilder.ToImmutableAndFree()));
}
public virtual BoundStatement InstrumentExpressionStatement(BoundExpressionStatement original, BoundStatement rewritten)
{
return(InstrumentStatement(original, rewritten));
}
/// <summary>
/// Generates a submission initialization part of a Script type constructor that represents an interactive submission.
/// </summary>
/// <remarks>
/// The constructor takes a parameter of type Roslyn.Scripting.Session - the session reference.
/// It adds the object being constructed into the session by calling Microsoft.CSharp.RuntimeHelpers.SessionHelpers.SetSubmission,
/// and retrieves strongly typed references on all previous submission script classes whose members are referenced by this submission.
/// The references are stored to fields of the submission (<paramref name="synthesizedFields"/>).
/// </remarks>
private static ImmutableArray <BoundStatement> MakeSubmissionInitialization(CSharpSyntaxNode syntax, MethodSymbol submissionConstructor, SynthesizedSubmissionFields synthesizedFields, CSharpCompilation compilation)
{
Debug.Assert(submissionConstructor.ParameterCount == 2);
BoundStatement[] result = new BoundStatement[1 + synthesizedFields.Count];
var sessionReference = new BoundParameter(syntax, submissionConstructor.Parameters[0])
{
WasCompilerGenerated = true
};
var submissionGetter = (MethodSymbol)compilation.GetWellKnownTypeMember(
WellKnownMember.Microsoft_CSharp_RuntimeHelpers_SessionHelpers__GetSubmission
);
var submissionAdder = (MethodSymbol)compilation.GetWellKnownTypeMember(
WellKnownMember.Microsoft_CSharp_RuntimeHelpers_SessionHelpers__SetSubmission
);
// TODO: report missing adder/getter
Debug.Assert((object)submissionAdder != null && (object)submissionGetter != null);
var intType = compilation.GetSpecialType(SpecialType.System_Int32);
var thisReference = new BoundThisReference(syntax, submissionConstructor.ContainingType)
{
WasCompilerGenerated = true
};
int i = 0;
// hostObject = (THostObject)SessionHelpers.SetSubmission(<session>, <slot index>, this);
var slotIndex = compilation.GetSubmissionSlotIndex();
Debug.Assert(slotIndex >= 0);
BoundExpression setSubmission = BoundCall.Synthesized(syntax,
null,
submissionAdder,
sessionReference,
new BoundLiteral(syntax, ConstantValue.Create(slotIndex), intType)
{
WasCompilerGenerated = true
},
thisReference
);
var hostObjectField = synthesizedFields.GetHostObjectField();
if ((object)hostObjectField != null)
{
setSubmission = new BoundAssignmentOperator(syntax,
new BoundFieldAccess(syntax, thisReference, hostObjectField, ConstantValue.NotAvailable)
{
WasCompilerGenerated = true
},
BoundConversion.Synthesized(syntax,
setSubmission,
Conversion.ExplicitReference,
false,
true,
ConstantValue.NotAvailable,
hostObjectField.Type
),
hostObjectField.Type
)
{
WasCompilerGenerated = true
};
}
result[i++] = new BoundExpressionStatement(syntax, setSubmission)
{
WasCompilerGenerated = true
};
foreach (var field in synthesizedFields.FieldSymbols)
{
var targetScriptClass = (ImplicitNamedTypeSymbol)field.Type;
var targetSubmissionId = targetScriptClass.DeclaringCompilation.GetSubmissionSlotIndex();
Debug.Assert(targetSubmissionId >= 0);
// this.<field> = (<FieldType>)SessionHelpers.GetSubmission(<session>, <i>);
result[i++] =
new BoundExpressionStatement(syntax,
new BoundAssignmentOperator(syntax,
new BoundFieldAccess(syntax, thisReference, field, ConstantValue.NotAvailable)
{
WasCompilerGenerated = true
},
BoundConversion.Synthesized(syntax,
BoundCall.Synthesized(syntax,
null,
submissionGetter,
sessionReference,
new BoundLiteral(syntax, ConstantValue.Create(targetSubmissionId), intType)
{
WasCompilerGenerated = true
}),
Conversion.ExplicitReference,
false,
true,
ConstantValue.NotAvailable,
targetScriptClass
),
targetScriptClass
)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
}
Debug.Assert(i == result.Length);
return(result.AsImmutableOrNull());
}
internal static BoundBlock ConstructDestructorBody(MethodSymbol method, BoundBlock block)
{
var syntax = block.Syntax;
Debug.Assert(method.MethodKind == MethodKind.Destructor);
Debug.Assert(syntax.Kind() == SyntaxKind.Block || syntax.Kind() == SyntaxKind.ArrowExpressionClause);
// If this is a destructor and a base type has a Finalize method (see GetBaseTypeFinalizeMethod for exact
// requirements), then we need to call that method in a finally block. Otherwise, just return block as-is.
// NOTE: the Finalize method need not be a destructor or be overridden by the current method.
MethodSymbol baseTypeFinalize = GetBaseTypeFinalizeMethod(method);
if ((object)baseTypeFinalize != null)
{
BoundStatement baseFinalizeCall = new BoundExpressionStatement(
syntax,
BoundCall.Synthesized(
syntax,
new BoundBaseReference(
syntax,
method.ContainingType)
{
WasCompilerGenerated = true
},
baseTypeFinalize))
{
WasCompilerGenerated = true
};
if (syntax.Kind() == SyntaxKind.Block)
{
//sequence point to mimic Dev10
baseFinalizeCall = new BoundSequencePointWithSpan(
syntax,
baseFinalizeCall,
((BlockSyntax)syntax).CloseBraceToken.Span);
}
return(new BoundBlock(
syntax,
ImmutableArray <LocalSymbol> .Empty,
ImmutableArray.Create <BoundStatement>(
new BoundTryStatement(
syntax,
block,
ImmutableArray <BoundCatchBlock> .Empty,
new BoundBlock(
syntax,
ImmutableArray <LocalSymbol> .Empty,
ImmutableArray.Create <BoundStatement>(
baseFinalizeCall)
)
{
WasCompilerGenerated = true
}
)
{
WasCompilerGenerated = true
})));
}
return(block);
}
/// <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);
/// </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);
MethodSymbol updateMethod = (MethodSymbol)compilation.GetSpecialTypeMember(isAddMethod ? SpecialMember.System_Delegate__Combine : SpecialMember.System_Delegate__Remove);
MethodSymbol compareExchangeMethod = GetConstructedCompareExchangeMethod(delegateType, compilation, accessor.Locations[0], diagnostics);
if ((object)compareExchangeMethod == null)
{
return(new BoundBlock(syntax,
localsOpt: default(ImmutableArray <LocalSymbol>),
statements: ImmutableArray.Create <BoundStatement>(
new BoundReturnStatement(syntax,
expressionOpt: null)
{
WasCompilerGenerated = true
}))
{
WasCompilerGenerated = true
});
}
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);
boundTmps[i] = new BoundLocal(syntax, tmps[i], null, delegateType);
}
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
};
// 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)
BoundExpression 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
};
BoundStatement @return = new BoundReturnStatement(syntax,
expressionOpt: null)
{
WasCompilerGenerated = true
};
return(new BoundBlock(syntax,
localsOpt: tmps.AsImmutableOrNull(),
statements: ImmutableArray.Create <BoundStatement>(
tmp0Init,
loopStart,
tmp1Update,
tmp2Update,
tmp0Update,
loopEnd,
@return))
{
WasCompilerGenerated = true
});
}
/// <summary>
/// Construct a body for an auto-property accessor (updating or returning the backing field).
/// </summary>
internal static BoundBlock ConstructAutoPropertyAccessorBody(SourceMethodSymbol accessor)
{
Debug.Assert(accessor.MethodKind == MethodKind.PropertyGet || accessor.MethodKind == MethodKind.PropertySet);
var property = (SourcePropertySymbol)accessor.AssociatedSymbol;
CSharpSyntaxNode syntax = property.CSharpSyntaxNode;
BoundExpression thisReference = null;
if (!accessor.IsStatic)
{
var thisSymbol = accessor.ThisParameter;
thisReference = new BoundThisReference(syntax, thisSymbol.Type)
{
WasCompilerGenerated = true
};
}
var field = property.BackingField;
var fieldAccess = new BoundFieldAccess(syntax, thisReference, field, ConstantValue.NotAvailable)
{
WasCompilerGenerated = true
};
BoundStatement statement;
if (accessor.MethodKind == MethodKind.PropertyGet)
{
statement = new BoundReturnStatement(syntax, fieldAccess)
{
WasCompilerGenerated = true
};
}
else
{
Debug.Assert(accessor.MethodKind == MethodKind.PropertySet);
var parameter = accessor.Parameters[0];
statement = new BoundExpressionStatement(
syntax,
new BoundAssignmentOperator(
syntax,
fieldAccess,
new BoundParameter(syntax, parameter)
{
WasCompilerGenerated = true
},
property.Type)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = true
};
}
statement = new BoundSequencePoint(accessor.SyntaxNode, statement)
{
WasCompilerGenerated = true
};
return(new BoundBlock(syntax, default(ImmutableArray <LocalSymbol>), ImmutableArray.Create <BoundStatement>(statement))
{
WasCompilerGenerated = true
});
}
/// <summary>
/// Lower "using (expression) statement" to a try-finally block.
/// </summary>
private BoundBlock RewriteExpressionUsingStatement(BoundUsingStatement node, BoundBlock tryBlock)
{
Debug.Assert(node.ExpressionOpt != null);
Debug.Assert(node.DeclarationsOpt == null);
// See comments in BuildUsingTryFinally for the details of the lowering to try-finally.
//
// SPEC: A using statement of the form "using (expression) statement; " has the
// SPEC: same three possible expansions [ as "using (ResourceType r = expression) statement; ]
// SPEC: but in this case ResourceType is implicitly the compile-time type of the expression,
// SPEC: and the resource variable is inaccessible to and invisible to the embedded statement.
//
// DELIBERATE SPEC VIOLATION:
//
// The spec quote above implies that the expression must have a type; in fact we allow
// the expression to be null.
//
// If expr is the constant null then we can elide the whole thing and simply generate the statement.
BoundExpression rewrittenExpression = (BoundExpression)Visit(node.ExpressionOpt);
if (rewrittenExpression.ConstantValue == ConstantValue.Null)
{
return(tryBlock);
}
// Otherwise, we lower "using(expression) statement;" as follows:
//
// * If the expression is of type dynamic then we lower as though the user had written
//
// using(IDisposable temp = (IDisposable)expression) statement;
//
// Note that we have to do the conversion early, not in the finally block, because
// if the conversion fails at runtime with an exception then the exception must happen
// before the statement runs.
//
// * Otherwise we lower as though the user had written
//
// using(ResourceType temp = expression) statement;
//
TypeSymbol expressionType = rewrittenExpression.Type;
CSharpSyntaxNode expressionSyntax = rewrittenExpression.Syntax;
UsingStatementSyntax usingSyntax = (UsingStatementSyntax)node.Syntax;
BoundAssignmentOperator tempAssignment;
BoundLocal boundTemp;
if ((object)expressionType == null || expressionType.IsDynamic())
{
// IDisposable temp = (IDisposable) expr;
BoundExpression tempInit = MakeConversion(
expressionSyntax,
rewrittenExpression,
node.IDisposableConversion.Kind,
this.compilation.GetSpecialType(SpecialType.System_IDisposable),
@checked: false,
constantValueOpt: rewrittenExpression.ConstantValue);
boundTemp = this.factory.StoreToTemp(tempInit, out tempAssignment);
}
else
{
// ResourceType temp = expr;
boundTemp = this.factory.StoreToTemp(rewrittenExpression, tempKind: TempKind.Using, store: out tempAssignment);
}
BoundStatement expressionStatement = new BoundExpressionStatement(expressionSyntax, tempAssignment);
if (this.generateDebugInfo)
{
// NOTE: unlike in the assignment case, the sequence point is on the using keyword, not the expression.
expressionStatement = new BoundSequencePointWithSpan(usingSyntax, expressionStatement, usingSyntax.UsingKeyword.Span);
}
BoundStatement tryFinally = RewriteUsingStatementTryFinally(usingSyntax, tryBlock, boundTemp);
// { ResourceType temp = expr; try { ... } finally { ... } }
return(new BoundBlock(
syntax: usingSyntax,
localsOpt: ImmutableArray.Create <LocalSymbol>(boundTemp.LocalSymbol),
statements: ImmutableArray.Create <BoundStatement>(expressionStatement, tryFinally)));
}
internal static BoundBlock ConstructAutoPropertyAccessorBody(
SourceMemberMethodSymbol accessor
)
{
Debug.Assert(
accessor.MethodKind == MethodKind.PropertyGet ||
accessor.MethodKind == MethodKind.PropertySet
);
var property = (SourcePropertySymbolBase)accessor.AssociatedSymbol;
CSharpSyntaxNode syntax = property.CSharpSyntaxNode;
BoundExpression thisReference = null;
if (!accessor.IsStatic)
{
var thisSymbol = accessor.ThisParameter;
thisReference = new BoundThisReference(syntax, thisSymbol.Type)
{
WasCompilerGenerated = true
};
}
var field = property.BackingField;
var fieldAccess = new BoundFieldAccess(
syntax,
thisReference,
field,
ConstantValue.NotAvailable
)
{
WasCompilerGenerated = true
};
BoundStatement statement;
if (accessor.MethodKind == MethodKind.PropertyGet)
{
statement = new BoundReturnStatement(
accessor.SyntaxNode,
RefKind.None,
fieldAccess
);
}
else
{
Debug.Assert(accessor.MethodKind == MethodKind.PropertySet);
var parameter = accessor.Parameters[0];
statement = new BoundExpressionStatement(
accessor.SyntaxNode,
new BoundAssignmentOperator(
syntax,
fieldAccess,
new BoundParameter(syntax, parameter)
{
WasCompilerGenerated = true
},
property.Type
)
{
WasCompilerGenerated = true
}
);
}
return(BoundBlock.SynthesizedNoLocals(syntax, statement));
}
/// <summary>
/// Generate a thread-safe accessor for a WinRT field-like event.
///
/// Add:
/// return EventRegistrationTokenTable<Event>.GetOrCreateEventRegistrationTokenTable(ref _tokenTable).AddEventHandler(value);
///
/// Remove:
/// EventRegistrationTokenTable<Event>.GetOrCreateEventRegistrationTokenTable(ref _tokenTable).RemoveEventHandler(value);
/// </summary>
internal static BoundBlock ConstructFieldLikeEventAccessorBody_WinRT(SourceEventSymbol eventSymbol, bool isAddMethod, CSharpCompilation compilation, DiagnosticBag diagnostics)
{
CSharpSyntaxNode syntax = eventSymbol.CSharpSyntaxNode;
MethodSymbol accessor = isAddMethod ? eventSymbol.AddMethod : eventSymbol.RemoveMethod;
Debug.Assert((object)accessor != null);
FieldSymbol field = eventSymbol.AssociatedField;
Debug.Assert((object)field != null);
NamedTypeSymbol fieldType = (NamedTypeSymbol)field.Type;
Debug.Assert(fieldType.Name == "EventRegistrationTokenTable");
MethodSymbol getOrCreateMethod = (MethodSymbol)Binder.GetWellKnownTypeMember(
compilation,
WellKnownMember.System_Runtime_InteropServices_WindowsRuntime_EventRegistrationTokenTable_T__GetOrCreateEventRegistrationTokenTable,
diagnostics,
syntax: syntax);
if ((object)getOrCreateMethod == null)
{
Debug.Assert(diagnostics.HasAnyErrors());
return(null);
}
getOrCreateMethod = getOrCreateMethod.AsMember(fieldType);
WellKnownMember processHandlerMember = isAddMethod
? WellKnownMember.System_Runtime_InteropServices_WindowsRuntime_EventRegistrationTokenTable_T__AddEventHandler
: WellKnownMember.System_Runtime_InteropServices_WindowsRuntime_EventRegistrationTokenTable_T__RemoveEventHandler;
MethodSymbol processHandlerMethod = (MethodSymbol)Binder.GetWellKnownTypeMember(
compilation,
processHandlerMember,
diagnostics,
syntax: syntax);
if ((object)processHandlerMethod == null)
{
Debug.Assert(diagnostics.HasAnyErrors());
return(null);
}
processHandlerMethod = processHandlerMethod.AsMember(fieldType);
// _tokenTable
BoundFieldAccess fieldAccess = new BoundFieldAccess(
syntax,
field.IsStatic ? null : new BoundThisReference(syntax, accessor.ThisParameter.Type),
field,
constantValueOpt: null)
{
WasCompilerGenerated = true
};
// EventRegistrationTokenTable<Event>.GetOrCreateEventRegistrationTokenTable(ref _tokenTable)
BoundCall getOrCreateCall = BoundCall.Synthesized(
syntax,
receiverOpt: null,
method: getOrCreateMethod,
arg0: fieldAccess);
// value
BoundParameter parameterAccess = new BoundParameter(
syntax,
accessor.Parameters[0]);
// EventRegistrationTokenTable<Event>.GetOrCreateEventRegistrationTokenTable(ref _tokenTable).AddHandler(value) // or RemoveHandler
BoundCall processHandlerCall = BoundCall.Synthesized(
syntax,
receiverOpt: getOrCreateCall,
method: processHandlerMethod,
arg0: parameterAccess);
if (isAddMethod)
{
// {
// return EventRegistrationTokenTable<Event>.GetOrCreateEventRegistrationTokenTable(ref _tokenTable).AddHandler(value);
// }
BoundStatement returnStatement = BoundReturnStatement.Synthesized(syntax, RefKind.None, processHandlerCall);
return(BoundBlock.SynthesizedNoLocals(syntax, returnStatement));
}
else
{
// {
// EventRegistrationTokenTable<Event>.GetOrCreateEventRegistrationTokenTable(ref _tokenTable).RemoveHandler(value);
// return;
// }
BoundStatement callStatement = new BoundExpressionStatement(syntax, processHandlerCall);
BoundStatement returnStatement = new BoundReturnStatement(syntax, RefKind.None, expressionOpt: null);
return(BoundBlock.SynthesizedNoLocals(syntax, callStatement, returnStatement));
}
}
private static BoundStatement RewriteFieldInitializer(BoundFieldInitializer fieldInit)
{
var syntax = fieldInit.Syntax;
var boundReceiver = fieldInit.Field.IsStatic ? null :
new BoundThisReference(syntax, fieldInit.Field.ContainingType);
// Mark this as CompilerGenerated so that the local rewriter doesn't add a sequence point.
BoundStatement boundStatement =
new BoundExpressionStatement(syntax,
new BoundAssignmentOperator(syntax,
new BoundFieldAccess(syntax,
boundReceiver,
fieldInit.Field,
constantValueOpt: null),
fieldInit.InitialValue,
fieldInit.Field.Type)
{ WasCompilerGenerated = true })
{ WasCompilerGenerated = true };
Debug.Assert(syntax is ExpressionSyntax); // Should be the initial value.
Debug.Assert(syntax.Parent.Kind == SyntaxKind.EqualsValueClause);
switch (syntax.Parent.Parent.Kind)
{
case SyntaxKind.VariableDeclarator:
var declaratorSyntax = (VariableDeclaratorSyntax)syntax.Parent.Parent;
boundStatement = LocalRewriter.AddSequencePoint(declaratorSyntax, boundStatement);
break;
case SyntaxKind.PropertyDeclaration:
var declaration = (PropertyDeclarationSyntax)syntax.Parent.Parent;
boundStatement = LocalRewriter.AddSequencePoint(declaration, boundStatement);
break;
default:
throw ExceptionUtilities.Unreachable;
}
return boundStatement;
}
/// <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,
refKind: RefKind.None,
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(BoundBlock.SynthesizedNoLocals(syntax, @return));
}
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)),
conversion: Conversion.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(BoundBlock.SynthesizedNoLocals(syntax,
statements: ImmutableArray.Create <BoundStatement>(
eventUpdate,
@return)));
}
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)),
conversion: Conversion.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(),
localFunctions: ImmutableArray <LocalFunctionSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(
tmp0Init,
loopStart,
tmp1Update,
tmp2Update,
tmp0Update,
loopEnd,
@return))
{
WasCompilerGenerated = true
});
}
/// <summary>
/// Report an error if this is an awaitable async method invocation that is not being awaited.
/// </summary>
/// <remarks>
/// The checks here are equivalent to StatementBinder::CheckForUnobservedAwaitable() in the native compiler.
/// </remarks>
private void CheckForUnobservedAwaitable(BoundExpressionStatement expressionStatement, DiagnosticBag diagnostics)
{
if (expressionStatement == null)
{
return;
}
BoundExpression expression = expressionStatement.Expression;
// If we don't have an expression or it doesn't have a type, just bail out
// now. Also, the dynamic type is always awaitable in an async method and
// could generate a lot of noise if we warned on it. Finally, we only want
// to warn on method calls, not other kinds of expressions.
if (expression == null
|| expression.Kind != BoundKind.Call
|| (object)expression.Type == null
|| expression.Type.IsDynamic()
|| expression.Type.SpecialType == SpecialType.System_Void)
{
return;
}
var call = (BoundCall)expression;
// First check if the target method is async.
if ((object)call.Method != null && call.Method.IsAsync)
{
Error(diagnostics, ErrorCode.WRN_UnobservedAwaitableExpression, expression.Syntax);
return;
}
// Then check if the method call returns a WinRT async type.
if (ImplementsWinRTAsyncInterface(call.Type))
{
Error(diagnostics, ErrorCode.WRN_UnobservedAwaitableExpression, expression.Syntax);
return;
}
// Finally, if we're in an async method, and the expression could be be awaited, report that it is instead discarded.
if (CouldBeAwaited(expression))
{
Error(diagnostics, ErrorCode.WRN_UnobservedAwaitableExpression, expression.Syntax);
}
}
public override BoundStatement InstrumentExpressionStatement(BoundExpressionStatement original, BoundStatement rewritten)
{
return(Previous.InstrumentExpressionStatement(original, rewritten));
}
public override BoundStatement InstrumentFieldOrPropertyInitializer(BoundExpressionStatement original, BoundStatement rewritten)
{
return(AddDynamicAnalysis(original, base.InstrumentExpressionStatement(original, rewritten)));
}
public override BoundStatement InstrumentFieldOrPropertyInitializer(BoundExpressionStatement original, BoundStatement rewritten)
{
return(Previous.InstrumentFieldOrPropertyInitializer(original, rewritten));
}
public override BoundNode VisitExpressionStatement(BoundExpressionStatement node)
{
// NOTE: not using a BoundNoOpStatement, since we don't want a nop to be emitted.
// CONSIDER: could use a BoundNoOpStatement (DevDiv #12943).
return(RewriteExpressionStatement(node) ?? BoundStatementList.Synthesized(node.Syntax));
}
/// <summary>
/// Generates the `ValueTask<bool> MoveNextAsync()` method.
/// </summary>
private void GenerateIAsyncEnumeratorImplementation_MoveNextAsync()
{
// Produce:
// if (State == StateMachineStates.FinishedStateMachine)
// {
// return default(ValueTask<bool>)
// }
// _valueOrEndPromise.Reset();
// var inst = this;
// _builder.Start(ref inst);
// return new ValueTask<bool>(this, _valueOrEndPromise.Version);
NamedTypeSymbol IAsyncEnumeratorOfElementType =
F.WellKnownType(WellKnownType.System_Collections_Generic_IAsyncEnumerator_T)
.Construct(_currentField.Type.TypeSymbol);
MethodSymbol IAsyncEnumerableOfElementType_MoveNextAsync =
F.WellKnownMethod(WellKnownMember.System_Collections_Generic_IAsyncEnumerator_T__MoveNextAsync)
.AsMember(IAsyncEnumeratorOfElementType);
// The implementation doesn't depend on the method body of the iterator method.
OpenMethodImplementation(IAsyncEnumerableOfElementType_MoveNextAsync, hasMethodBodyDependency: false);
var ifFinished = F.If(
// if (State == StateMachineStates.FinishedStateMachine)
F.IntEqual(F.Field(F.This(), stateField), F.Literal(StateMachineStates.FinishedStateMachine)),
// return default(ValueTask<bool>)
thenClause: F.Return(F.Default(IAsyncEnumerableOfElementType_MoveNextAsync.ReturnType.TypeSymbol)));
// _promiseOfValueOrEnd.Reset();
BoundFieldAccess promiseField = F.Field(F.This(), _promiseOfValueOrEndField);
var resetMethod = (MethodSymbol)F.WellKnownMethod(WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__Reset, isOptional: true)
.SymbolAsMember((NamedTypeSymbol)_promiseOfValueOrEndField.Type.TypeSymbol);
var callReset = F.ExpressionStatement(F.Call(promiseField, resetMethod));
// _builder.Start(ref inst);
Debug.Assert(!_asyncMethodBuilderMemberCollection.CheckGenericMethodConstraints);
MethodSymbol startMethod = _asyncMethodBuilderMemberCollection.Start.Construct(this.stateMachineType);
LocalSymbol instSymbol = F.SynthesizedLocal(this.stateMachineType);
BoundLocal instLocal = F.Local(instSymbol);
BoundExpressionStatement startCall = F.ExpressionStatement(
F.Call(
F.Field(F.This(), _builderField),
startMethod,
ImmutableArray.Create <BoundExpression>(instLocal)));
MethodSymbol valueTask_ctor =
F.WellKnownMethod(WellKnownMember.System_Threading_Tasks_ValueTask_T__ctor)
.AsMember((NamedTypeSymbol)IAsyncEnumerableOfElementType_MoveNextAsync.ReturnType.TypeSymbol);
MethodSymbol promise_get_Version =
F.WellKnownMethod(WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__get_Version)
.AsMember((NamedTypeSymbol)_promiseOfValueOrEndField.Type.TypeSymbol);
// return new ValueTask<bool>(this, _valueOrEndPromise.Version);
var returnStatement = F.Return(F.New(valueTask_ctor, F.This(), F.Call(F.Field(F.This(), _promiseOfValueOrEndField), promise_get_Version)));
F.CloseMethod(F.Block(
ImmutableArray.Create(instSymbol),
ifFinished,
callReset, // _promiseOfValueOrEnd.Reset();
F.Assignment(instLocal, F.This()), // var inst = this;
startCall, // _builder.Start(ref inst);
returnStatement));
}
public override BoundStatement InstrumentExpressionStatement(BoundExpressionStatement original, BoundStatement rewritten)
{
return Previous.InstrumentExpressionStatement(original, rewritten);
}
/// <summary>
/// Lower "using [await] (expression) statement" to a try-finally block.
/// </summary>
private BoundBlock MakeExpressionUsingStatement(BoundUsingStatement node, BoundBlock tryBlock)
{
Debug.Assert(node.ExpressionOpt != null);
Debug.Assert(node.DeclarationsOpt == null);
// See comments in BuildUsingTryFinally for the details of the lowering to try-finally.
//
// SPEC: A using statement of the form "using (expression) statement; " has the
// SPEC: same three possible expansions [ as "using (ResourceType r = expression) statement; ]
// SPEC: but in this case ResourceType is implicitly the compile-time type of the expression,
// SPEC: and the resource variable is inaccessible to and invisible to the embedded statement.
//
// DELIBERATE SPEC VIOLATION:
//
// The spec quote above implies that the expression must have a type; in fact we allow
// the expression to be null.
//
// If expr is the constant null then we can elide the whole thing and simply generate the statement.
BoundExpression rewrittenExpression = (BoundExpression)Visit(node.ExpressionOpt);
if (rewrittenExpression.ConstantValue == ConstantValue.Null)
{
Debug.Assert(node.Locals.IsEmpty); // TODO: This might not be a valid assumption in presence of semicolon operator.
return(tryBlock);
}
// Otherwise, we lower "using(expression) statement;" as follows:
//
// * If the expression is of type dynamic then we lower as though the user had written
//
// using(IDisposable temp = (IDisposable)expression) statement;
//
// Note that we have to do the conversion early, not in the finally block, because
// if the conversion fails at runtime with an exception then the exception must happen
// before the statement runs.
//
// * Otherwise we lower as though the user had written
//
// using(ResourceType temp = expression) statement;
//
TypeSymbol expressionType = rewrittenExpression.Type;
SyntaxNode expressionSyntax = rewrittenExpression.Syntax;
UsingStatementSyntax usingSyntax = (UsingStatementSyntax)node.Syntax;
BoundAssignmentOperator tempAssignment;
BoundLocal boundTemp;
if ((object)expressionType == null || expressionType.IsDynamic())
{
// IDisposable temp = (IDisposable) expr;
// or
// IAsyncDisposable temp = (IAsyncDisposable) expr;
TypeSymbol iDisposableType = node.AwaitOpt is null?
_compilation.GetSpecialType(SpecialType.System_IDisposable) :
_compilation.GetWellKnownType(WellKnownType.System_IAsyncDisposable);
BoundExpression tempInit = MakeConversionNode(
expressionSyntax,
rewrittenExpression,
Conversion.GetTrivialConversion(node.IDisposableConversion.Kind),
iDisposableType,
@checked: false,
constantValueOpt: rewrittenExpression.ConstantValue);
boundTemp = _factory.StoreToTemp(tempInit, out tempAssignment, kind: SynthesizedLocalKind.Using);
}
else
{
// ResourceType temp = expr;
boundTemp = _factory.StoreToTemp(rewrittenExpression, out tempAssignment, syntaxOpt: usingSyntax, kind: SynthesizedLocalKind.Using);
}
BoundStatement expressionStatement = new BoundExpressionStatement(expressionSyntax, tempAssignment);
if (this.Instrument)
{
expressionStatement = _instrumenter.InstrumentUsingTargetCapture(node, expressionStatement);
}
BoundStatement tryFinally = RewriteUsingStatementTryFinally(usingSyntax, tryBlock, boundTemp, usingSyntax.AwaitKeyword, node.AwaitOpt, node.DisposeMethodOpt);
// { ResourceType temp = expr; try { ... } finally { ... } }
return(new BoundBlock(
syntax: usingSyntax,
locals: node.Locals.Add(boundTemp.LocalSymbol),
statements: ImmutableArray.Create <BoundStatement>(expressionStatement, tryFinally)));
}
/// <summary>
/// Lower a foreach loop that will enumerate a collection using an enumerator.
///
/// E e = ((C)(x)).GetEnumerator()
/// try {
/// while (e.MoveNext()) {
/// V v = (V)(T)e.Current;
/// // body
/// }
/// }
/// finally {
/// // clean up e
/// }
/// </summary>
private BoundStatement RewriteEnumeratorForEachStatement(BoundForEachStatement node)
{
ForEachStatementSyntax forEachSyntax = (ForEachStatementSyntax)node.Syntax;
ForEachEnumeratorInfo enumeratorInfo = node.EnumeratorInfoOpt;
Debug.Assert(enumeratorInfo != null);
BoundExpression collectionExpression = GetUnconvertedCollectionExpression(node);
BoundExpression rewrittenExpression = (BoundExpression)Visit(collectionExpression);
BoundStatement rewrittenBody = (BoundStatement)Visit(node.Body);
TypeSymbol enumeratorType = enumeratorInfo.GetEnumeratorMethod.ReturnType;
TypeSymbol elementType = enumeratorInfo.ElementType;
// E e
LocalSymbol enumeratorVar = _factory.SynthesizedLocal(enumeratorType, syntax: forEachSyntax, kind: SynthesizedLocalKind.ForEachEnumerator);
// Reference to e.
BoundLocal boundEnumeratorVar = MakeBoundLocal(forEachSyntax, enumeratorVar, enumeratorType);
// ((C)(x)).GetEnumerator() or (x).GetEnumerator();
BoundExpression enumeratorVarInitValue = SynthesizeCall(forEachSyntax, rewrittenExpression, enumeratorInfo.GetEnumeratorMethod, enumeratorInfo.CollectionConversion, enumeratorInfo.CollectionType);
// E e = ((C)(x)).GetEnumerator();
BoundStatement enumeratorVarDecl = MakeLocalDeclaration(forEachSyntax, enumeratorVar, enumeratorVarInitValue);
AddForEachExpressionSequencePoint(forEachSyntax, ref enumeratorVarDecl);
// V v
LocalSymbol iterationVar = node.IterationVariable;
//(V)(T)e.Current
BoundExpression iterationVarAssignValue = MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundEnumeratorVar,
method: enumeratorInfo.CurrentPropertyGetter),
conversion: enumeratorInfo.CurrentConversion,
rewrittenType: elementType,
@checked: node.Checked),
conversion: node.ElementConversion,
rewrittenType: iterationVar.Type,
@checked: node.Checked);
// V v = (V)(T)e.Current;
BoundStatement iterationVarDecl = MakeLocalDeclaration(forEachSyntax, iterationVar, iterationVarAssignValue);
AddForEachIterationVariableSequencePoint(forEachSyntax, ref iterationVarDecl);
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* node.Body */
// }
var rewrittenBodyBlock = CreateBlockDeclaringIterationVariable(iterationVar, iterationVarDecl, rewrittenBody, forEachSyntax);
BoundStatement whileLoop = RewriteWhileStatement(
syntax: forEachSyntax,
rewrittenCondition: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundEnumeratorVar,
method: enumeratorInfo.MoveNextMethod),
conditionSequencePointSpan: forEachSyntax.InKeyword.Span,
rewrittenBody: rewrittenBodyBlock,
breakLabel: node.BreakLabel,
continueLabel: node.ContinueLabel,
hasErrors: false);
BoundStatement result;
MethodSymbol disposeMethod;
if (enumeratorInfo.NeedsDisposeMethod && Binder.TryGetSpecialTypeMember(_compilation, SpecialMember.System_IDisposable__Dispose, forEachSyntax, _diagnostics, out disposeMethod))
{
Binder.ReportDiagnosticsIfObsolete(_diagnostics, disposeMethod, forEachSyntax,
hasBaseReceiver: false,
containingMember: _factory.CurrentMethod,
containingType: _factory.CurrentType,
location: enumeratorInfo.Location);
BoundBlock finallyBlockOpt;
var idisposableTypeSymbol = disposeMethod.ContainingType;
var conversions = new TypeConversions(_factory.CurrentMethod.ContainingAssembly.CorLibrary);
HashSet<DiagnosticInfo> useSiteDiagnostics = null;
var isImplicit = conversions.ClassifyImplicitConversion(enumeratorType, idisposableTypeSymbol, ref useSiteDiagnostics).IsImplicit;
_diagnostics.Add(forEachSyntax, useSiteDiagnostics);
if (isImplicit)
{
Debug.Assert(enumeratorInfo.NeedsDisposeMethod);
Conversion receiverConversion = enumeratorType.IsStructType() ?
Conversion.Boxing :
Conversion.ImplicitReference;
// ((IDisposable)e).Dispose(); or e.Dispose();
BoundStatement disposeCall = new BoundExpressionStatement(forEachSyntax,
expression: SynthesizeCall(forEachSyntax, boundEnumeratorVar, disposeMethod, receiverConversion, idisposableTypeSymbol));
BoundStatement disposeStmt;
if (enumeratorType.IsValueType)
{
// No way for the struct to be nullable and disposable.
Debug.Assert(((TypeSymbol)enumeratorType.OriginalDefinition).SpecialType != SpecialType.System_Nullable_T);
// For non-nullable structs, no null check is required.
disposeStmt = disposeCall;
}
else
{
// NB: cast to object missing from spec. Needed to ignore user-defined operators and box type parameters.
// if ((object)e != null) ((IDisposable)e).Dispose();
disposeStmt = RewriteIfStatement(
syntax: forEachSyntax,
rewrittenCondition: new BoundBinaryOperator(forEachSyntax,
operatorKind: BinaryOperatorKind.NotEqual,
left: MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: boundEnumeratorVar,
conversion: enumeratorInfo.EnumeratorConversion,
rewrittenType: _compilation.GetSpecialType(SpecialType.System_Object),
@checked: false),
right: MakeLiteral(forEachSyntax,
constantValue: ConstantValue.Null,
type: null),
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: _compilation.GetSpecialType(SpecialType.System_Boolean)),
rewrittenConsequence: disposeCall,
rewrittenAlternativeOpt: null,
hasErrors: false);
}
finallyBlockOpt = new BoundBlock(forEachSyntax,
locals: ImmutableArray<LocalSymbol>.Empty,
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(disposeStmt));
}
else
{
Debug.Assert(!enumeratorType.IsSealed);
// IDisposable d
LocalSymbol disposableVar = _factory.SynthesizedLocal(idisposableTypeSymbol);
// Reference to d.
BoundLocal boundDisposableVar = MakeBoundLocal(forEachSyntax, disposableVar, idisposableTypeSymbol);
BoundTypeExpression boundIDisposableTypeExpr = new BoundTypeExpression(forEachSyntax,
aliasOpt: null,
type: idisposableTypeSymbol);
// e as IDisposable
BoundExpression disposableVarInitValue = new BoundAsOperator(forEachSyntax,
operand: boundEnumeratorVar,
targetType: boundIDisposableTypeExpr,
conversion: Conversion.ExplicitReference, // Explicit so the emitter won't optimize it away.
type: idisposableTypeSymbol);
// IDisposable d = e as IDisposable;
BoundStatement disposableVarDecl = MakeLocalDeclaration(forEachSyntax, disposableVar, disposableVarInitValue);
// if (d != null) d.Dispose();
BoundStatement ifStmt = RewriteIfStatement(
syntax: forEachSyntax,
rewrittenCondition: new BoundBinaryOperator(forEachSyntax,
operatorKind: BinaryOperatorKind.NotEqual, // reference equality
left: boundDisposableVar,
right: MakeLiteral(forEachSyntax,
constantValue: ConstantValue.Null,
type: null),
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: _compilation.GetSpecialType(SpecialType.System_Boolean)),
rewrittenConsequence: new BoundExpressionStatement(forEachSyntax,
expression: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundDisposableVar,
method: disposeMethod)),
rewrittenAlternativeOpt: null,
hasErrors: false);
// IDisposable d = e as IDisposable;
// if (d != null) d.Dispose();
finallyBlockOpt = new BoundBlock(forEachSyntax,
locals: ImmutableArray.Create<LocalSymbol>(disposableVar),
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(disposableVarDecl, ifStmt));
}
// try {
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* loop body */
// }
// }
// finally {
// /* dispose of e */
// }
BoundStatement tryFinally = new BoundTryStatement(forEachSyntax,
tryBlock: new BoundBlock(forEachSyntax,
locals: ImmutableArray<LocalSymbol>.Empty,
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(whileLoop)),
catchBlocks: ImmutableArray<BoundCatchBlock>.Empty,
finallyBlockOpt: finallyBlockOpt);
// E e = ((C)(x)).GetEnumerator();
// try {
// /* as above */
result = new BoundBlock(
syntax: forEachSyntax,
locals: ImmutableArray.Create(enumeratorVar),
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(enumeratorVarDecl, tryFinally));
}
else
{
// E e = ((C)(x)).GetEnumerator();
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* loop body */
// }
result = new BoundBlock(
syntax: forEachSyntax,
locals: ImmutableArray.Create(enumeratorVar),
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(enumeratorVarDecl, whileLoop));
}
AddForEachKeywordSequencePoint(forEachSyntax, ref result);
return result;
}
private BoundStatement RewriteUsingStatementTryFinally(SyntaxNode syntax, BoundBlock tryBlock, BoundLocal local, SyntaxToken awaitKeywordOpt, AwaitableInfo awaitOpt, MethodSymbol methodOpt)
{
// SPEC: When ResourceType is a non-nullable value type, the expansion is:
// SPEC:
// SPEC: {
// SPEC: ResourceType resource = expr;
// SPEC: try { statement; }
// SPEC: finally { ((IDisposable)resource).Dispose(); }
// SPEC: }
// SPEC:
// SPEC: Otherwise, when Resource type is a nullable value type or
// SPEC: a reference type other than dynamic, the expansion is:
// SPEC:
// SPEC: {
// SPEC: ResourceType resource = expr;
// SPEC: try { statement; }
// SPEC: finally { if (resource != null) ((IDisposable)resource).Dispose(); }
// SPEC: }
// SPEC:
// SPEC: Otherwise, when ResourceType is dynamic, the expansion is:
// SPEC: {
// SPEC: dynamic resource = expr;
// SPEC: IDisposable d = (IDisposable)resource;
// SPEC: try { statement; }
// SPEC: finally { if (d != null) d.Dispose(); }
// SPEC: }
// SPEC:
// SPEC: An implementation is permitted to implement a given using statement
// SPEC: differently -- for example, for performance reasons -- as long as the
// SPEC: behavior is consistent with the above expansion.
//
// In the case of using-await statement, we'll use "IAsyncDisposable" instead of "IDisposable", "await DisposeAsync()" instead of "Dispose()"
//
// And we do in fact generate the code slightly differently than precisely how it is
// described above.
//
// First: if the type is a non-nullable value type then we do not do the
// *boxing conversion* from the resource to IDisposable. Rather, we do
// a *constrained virtual call* that elides the boxing if possible.
//
// Now, you might wonder if that is legal; isn't skipping the boxing producing
// an observable difference? Because if the value type is mutable and the Dispose
// mutates it, then skipping the boxing means that we are now mutating the original,
// not the boxed copy. But this is never observable. Either (1) we have "using(R r = x){}"
// and r is out of scope after the finally, so it is not possible to observe the mutation,
// or (2) we have "using(x) {}". But that has the semantics of "using(R temp = x){}",
// so again, we are not mutating x to begin with; we're always mutating a copy. Therefore
// it doesn't matter if we skip making *a copy of the copy*.
//
// This is what the dev10 compiler does, and we do so as well.
//
// Second: if the type is a nullable value type then we can similarly elide the boxing.
// We can generate
//
// {
// ResourceType resource = expr;
// try { statement; }
// finally { if (resource.HasValue) resource.GetValueOrDefault().Dispose(); }
// }
//
// Where again we do a constrained virtual call to Dispose, rather than boxing
// the value to IDisposable.
//
// Note that this optimization is *not* what the native compiler does; in this case
// the native compiler behavior is to test for HasValue, then *box* and convert
// the boxed value to IDisposable. There's no need to do that.
//
// Third: if we have "using(x)" and x is dynamic then obviously we need not generate
// "{ dynamic temp1 = x; IDisposable temp2 = (IDisposable) temp1; ... }". Rather, we elide
// the completely unnecessary first temporary.
Debug.Assert((awaitKeywordOpt == default) == (awaitOpt == default(AwaitableInfo)));
BoundExpression disposedExpression;
bool isNullableValueType = local.Type.IsNullableType();
if (isNullableValueType)
{
MethodSymbol getValueOrDefault = UnsafeGetNullableMethod(syntax, local.Type, SpecialMember.System_Nullable_T_GetValueOrDefault);
// local.GetValueOrDefault()
disposedExpression = BoundCall.Synthesized(syntax, local, getValueOrDefault);
}
else
{
// local
disposedExpression = local;
}
BoundExpression disposeCall = GenerateDisposeCall(syntax, disposedExpression, methodOpt, awaitOpt, awaitKeywordOpt);
// local.Dispose(); or await variant
BoundStatement disposeStatement = new BoundExpressionStatement(syntax, disposeCall);
BoundExpression ifCondition;
if (isNullableValueType)
{
// local.HasValue
ifCondition = MakeNullableHasValue(syntax, local);
}
else if (local.Type.IsValueType)
{
ifCondition = null;
}
else
{
// local != null
ifCondition = MakeNullCheck(syntax, local, BinaryOperatorKind.NotEqual);
}
BoundStatement finallyStatement;
if (ifCondition == null)
{
// local.Dispose(); or await variant
finallyStatement = disposeStatement;
}
else
{
// if (local != null) local.Dispose();
// or
// if (local.HasValue) local.GetValueOrDefault().Dispose();
// or
// await variants
finallyStatement = RewriteIfStatement(
syntax: syntax,
rewrittenCondition: ifCondition,
rewrittenConsequence: disposeStatement,
rewrittenAlternativeOpt: null,
hasErrors: false);
}
// try { ... } finally { if (local != null) local.Dispose(); }
// or
// nullable or await variants
BoundStatement tryFinally = new BoundTryStatement(
syntax: syntax,
tryBlock: tryBlock,
catchBlocks: ImmutableArray <BoundCatchBlock> .Empty,
finallyBlockOpt: BoundBlock.SynthesizedNoLocals(syntax, finallyStatement));
return(tryFinally);
}
/// <summary>
/// Wrap a given expression e into a block as either { e; } or { return e; }
/// Shared between lambda and expression-bodied method binding.
/// </summary>
internal BoundBlock CreateBlockFromExpression(CSharpSyntaxNode node, ImmutableArray<LocalSymbol> locals, RefKind refKind, BoundExpression expression, ExpressionSyntax expressionSyntax, DiagnosticBag diagnostics)
{
RefKind returnRefKind;
var returnType = GetCurrentReturnType(out returnRefKind);
var syntax = expressionSyntax ?? expression.Syntax;
BoundStatement statement;
if (IsInAsyncMethod() && refKind != RefKind.None)
{
// This can happen if we are binding an async anonymous method to a delegate type.
Error(diagnostics, ErrorCode.ERR_MustNotHaveRefReturn, syntax);
statement = new BoundReturnStatement(syntax, refKind, expression) { WasCompilerGenerated = true };
}
else if ((object)returnType != null)
{
if ((refKind != RefKind.None) != (returnRefKind != RefKind.None))
{
var errorCode = refKind != RefKind.None
? ErrorCode.ERR_MustNotHaveRefReturn
: ErrorCode.ERR_MustHaveRefReturn;
Error(diagnostics, errorCode, syntax);
statement = new BoundReturnStatement(syntax, RefKind.None, expression) { WasCompilerGenerated = true };
}
else if (returnType.SpecialType == SpecialType.System_Void || IsTaskReturningAsyncMethod())
{
// If the return type is void then the expression is required to be a legal
// statement expression.
Debug.Assert(expressionSyntax != null || !IsValidStatementExpression(expression.Syntax, expression));
bool errors = false;
if (expressionSyntax == null || !IsValidStatementExpression(expressionSyntax, expression))
{
Error(diagnostics, ErrorCode.ERR_IllegalStatement, syntax);
errors = true;
}
// Don't mark compiler generated so that the rewriter generates sequence points
var expressionStatement = new BoundExpressionStatement(syntax, expression, errors);
CheckForUnobservedAwaitable(expression, diagnostics);
statement = expressionStatement;
}
else
{
expression = CreateReturnConversion(syntax, diagnostics, expression, refKind, returnType);
statement = new BoundReturnStatement(syntax, returnRefKind, expression) { WasCompilerGenerated = true };
}
}
else if (expression.Type?.SpecialType == SpecialType.System_Void)
{
statement = new BoundExpressionStatement(syntax, expression) { WasCompilerGenerated = true };
}
else
{
statement = new BoundReturnStatement(syntax, refKind, expression) { WasCompilerGenerated = true };
}
// Need to attach the tree for when we generate sequence points.
return new BoundBlock(node, locals, ImmutableArray<LocalFunctionSymbol>.Empty, ImmutableArray.Create(statement)) { WasCompilerGenerated = node.Kind() != SyntaxKind.ArrowExpressionClause };
}
// 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;
}
public override BoundNode VisitExpressionStatement(BoundExpressionStatement node)
{
if (node.Expression.Kind == BoundKind.AwaitExpression)
{
var awaitExpression = VisitAwaitExpression((BoundAwaitExpression)node.Expression, resultsDiscarded: true);
return node.Update(awaitExpression);
}
return base.VisitExpressionStatement(node);
}
public override BoundNode VisitExpressionStatement(BoundExpressionStatement node)
{
// expressions cannot contain labels, branches or yields.
return null;
}
internal static ImmutableArray <BoundStatement> ConstructScriptConstructorBody(
BoundStatement loweredBody,
MethodSymbol constructor,
SynthesizedSubmissionFields previousSubmissionFields,
CSharpCompilation compilation
)
{
// Script field initializers have to be emitted after the call to the base constructor because they can refer to "this" instance.
//
// Unlike regular field initializers, initializers of global script variables can access "this" instance.
// If the base class had a constructor that initializes its state a global variable would access partially initialized object.
// For this reason Script class must always derive directly from a class that has no state (System.Object).
SyntaxNode syntax = loweredBody.Syntax;
// base constructor call:
Debug.Assert(
(object)constructor.ContainingType.BaseTypeNoUseSiteDiagnostics == null ||
constructor.ContainingType.BaseTypeNoUseSiteDiagnostics.SpecialType
== SpecialType.System_Object
);
var objectType = constructor.ContainingAssembly.GetSpecialType(
SpecialType.System_Object
);
BoundExpression receiver = new BoundThisReference(syntax, constructor.ContainingType)
{
WasCompilerGenerated = true
};
BoundStatement baseConstructorCall = new BoundExpressionStatement(
syntax,
new BoundCall(
syntax,
receiverOpt: receiver,
method: objectType.InstanceConstructors[0],
arguments: ImmutableArray <BoundExpression> .Empty,
argumentNamesOpt: ImmutableArray <string> .Empty,
argumentRefKindsOpt: ImmutableArray <RefKind> .Empty,
isDelegateCall: false,
expanded: false,
invokedAsExtensionMethod: false,
argsToParamsOpt: ImmutableArray <int> .Empty,
defaultArguments: BitVector.Empty,
resultKind: LookupResultKind.Viable,
type: objectType
)
{
WasCompilerGenerated = true
}
)
{
WasCompilerGenerated = true
};
var statements = ArrayBuilder <BoundStatement> .GetInstance();
statements.Add(baseConstructorCall);
if (constructor.IsSubmissionConstructor)
{
// submission initialization:
MakeSubmissionInitialization(
statements,
syntax,
constructor,
previousSubmissionFields,
compilation
);
}
statements.Add(loweredBody);
return(statements.ToImmutableAndFree());
}
public override BoundNode VisitExpressionStatement(BoundExpressionStatement node)
{
BoundSpillSequence2 ss = null;
BoundExpression expr;
if (node.Expression.Kind == BoundKind.AwaitExpression)
{
// await expression with result discarded
var awaitExpression = (BoundAwaitExpression)node.Expression;
var expression = VisitExpression(ref ss, awaitExpression.Expression);
expr = awaitExpression.Update(expression, awaitExpression.GetAwaiter, awaitExpression.IsCompleted, awaitExpression.GetResult, awaitExpression.Type);
}
else
{
expr = VisitExpression(ref ss, node.Expression);
}
Debug.Assert(expr != null);
Debug.Assert(ss == null || ss.Value == null);
BoundStatement replacement = UpdateStatement(ss, node.Update(expr));
return replacement;
}
/// <summary>
/// Lowers a lock statement to a try-finally block that calls Monitor.Enter and Monitor.Exit
/// before and after the body, respectively.
/// </summary>
public override BoundNode VisitLockStatement(BoundLockStatement node)
{
LockStatementSyntax lockSyntax = (LockStatementSyntax)node.Syntax;
BoundExpression rewrittenArgument = VisitExpression(node.Argument);
BoundStatement rewrittenBody = (BoundStatement)Visit(node.Body);
TypeSymbol argumentType = rewrittenArgument.Type;
if ((object)argumentType == null)
{
// This isn't particularly elegant, but hopefully locking on null is
// not very common.
Debug.Assert(rewrittenArgument.ConstantValue == ConstantValue.Null);
argumentType = _compilation.GetSpecialType(SpecialType.System_Object);
rewrittenArgument = MakeLiteral(
rewrittenArgument.Syntax,
rewrittenArgument.ConstantValue,
argumentType); //need to have a non-null type here for TempHelpers.StoreToTemp.
}
if (argumentType.Kind == SymbolKind.TypeParameter)
{
// If the argument has a type parameter type, then we'll box it right away
// so that the same object is passed to both Monitor.Enter and Monitor.Exit.
argumentType = _compilation.GetSpecialType(SpecialType.System_Object);
rewrittenArgument = MakeConversionNode(
rewrittenArgument.Syntax,
rewrittenArgument,
Conversion.Boxing,
argumentType,
@checked: false,
constantValueOpt: rewrittenArgument.ConstantValue);
}
BoundAssignmentOperator assignmentToLockTemp;
BoundLocal boundLockTemp = _factory.StoreToTemp(rewrittenArgument, out assignmentToLockTemp, syntaxOpt: lockSyntax, kind: SynthesizedLocalKind.Lock);
BoundStatement boundLockTempInit = new BoundExpressionStatement(lockSyntax, assignmentToLockTemp);
BoundExpression exitCallExpr;
MethodSymbol exitMethod;
if (TryGetWellKnownTypeMember(lockSyntax, WellKnownMember.System_Threading_Monitor__Exit, out exitMethod))
{
exitCallExpr = BoundCall.Synthesized(
lockSyntax,
null,
exitMethod,
boundLockTemp);
}
else
{
exitCallExpr = new BoundBadExpression(lockSyntax, LookupResultKind.NotInvocable, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(boundLockTemp), ErrorTypeSymbol.UnknownResultType);
}
BoundStatement exitCall = new BoundExpressionStatement(lockSyntax, exitCallExpr);
MethodSymbol enterMethod;
if ((TryGetWellKnownTypeMember(lockSyntax, WellKnownMember.System_Threading_Monitor__Enter2, out enterMethod, isOptional: true) ||
TryGetWellKnownTypeMember(lockSyntax, WellKnownMember.System_Threading_Monitor__Enter, out enterMethod)) && // If we didn't find the overload introduced in .NET 4.0, then use the older one.
enterMethod.ParameterCount == 2)
{
// C# 4.0+ version
// L $lock = `argument`; // sequence point
// bool $lockTaken = false;
// try
// {
// Monitor.Enter($lock, ref $lockTaken);
// `body` // sequence point
// }
// finally
// { // hidden sequence point
// if ($lockTaken) Monitor.Exit($lock);
// }
TypeSymbol boolType = _compilation.GetSpecialType(SpecialType.System_Boolean);
BoundAssignmentOperator assignmentToLockTakenTemp;
BoundLocal boundLockTakenTemp = _factory.StoreToTemp(
MakeLiteral(rewrittenArgument.Syntax, ConstantValue.False, boolType),
store: out assignmentToLockTakenTemp,
syntaxOpt: lockSyntax,
kind: SynthesizedLocalKind.LockTaken);
BoundStatement boundLockTakenTempInit = new BoundExpressionStatement(lockSyntax, assignmentToLockTakenTemp);
BoundStatement enterCall = new BoundExpressionStatement(
lockSyntax,
BoundCall.Synthesized(
lockSyntax,
null,
enterMethod,
boundLockTemp,
boundLockTakenTemp));
exitCall = RewriteIfStatement(
lockSyntax,
boundLockTakenTemp,
exitCall,
null,
node.HasErrors);
return new BoundBlock(
lockSyntax,
ImmutableArray.Create(boundLockTemp.LocalSymbol, boundLockTakenTemp.LocalSymbol),
ImmutableArray<LocalFunctionSymbol>.Empty,
ImmutableArray.Create(
MakeInitialLockSequencePoint(boundLockTempInit, lockSyntax),
boundLockTakenTempInit,
new BoundTryStatement(
lockSyntax,
BoundBlock.SynthesizedNoLocals(lockSyntax, ImmutableArray.Create(
enterCall,
rewrittenBody)),
ImmutableArray<BoundCatchBlock>.Empty,
BoundBlock.SynthesizedNoLocals(lockSyntax,
exitCall))));
}
else
{
// Pre-4.0 version
// L $lock = `argument`; // sequence point
// Monitor.Enter($lock); // NB: before try-finally so we don't Exit if an exception prevents us from acquiring the lock.
// try
// {
// `body` // sequence point
// }
// finally
// {
// Monitor.Exit($lock); // hidden sequence point
// }
BoundExpression enterCallExpr;
if ((object)enterMethod != null)
{
Debug.Assert(enterMethod.ParameterCount == 1);
enterCallExpr = BoundCall.Synthesized(
lockSyntax,
null,
enterMethod,
boundLockTemp);
}
else
{
enterCallExpr = new BoundBadExpression(lockSyntax, LookupResultKind.NotInvocable, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(boundLockTemp), ErrorTypeSymbol.UnknownResultType);
}
BoundStatement enterCall = new BoundExpressionStatement(
lockSyntax,
enterCallExpr);
return new BoundBlock(
lockSyntax,
ImmutableArray.Create(boundLockTemp.LocalSymbol),
ImmutableArray<LocalFunctionSymbol>.Empty,
ImmutableArray.Create(
MakeInitialLockSequencePoint(boundLockTempInit, lockSyntax),
enterCall,
new BoundTryStatement(
lockSyntax,
BoundBlock.SynthesizedNoLocals(lockSyntax, rewrittenBody),
ImmutableArray<BoundCatchBlock>.Empty,
BoundBlock.SynthesizedNoLocals(lockSyntax, exitCall))));
}
}
private BoundStatement RewriteUsingStatementTryFinally(CSharpSyntaxNode syntax, BoundBlock tryBlock, BoundLocal local)
{
// SPEC: When ResourceType is a non-nullable value type, the expansion is:
// SPEC:
// SPEC: {
// SPEC: ResourceType resource = expr;
// SPEC: try { statement; }
// SPEC: finally { ((IDisposable)resource).Dispose(); }
// SPEC: }
// SPEC:
// SPEC: Otherwise, when Resource type is a nullable value type or
// SPEC: a reference type other than dynamic, the expansion is:
// SPEC:
// SPEC: {
// SPEC: ResourceType resource = expr;
// SPEC: try { statement; }
// SPEC: finally { if (resource != null) ((IDisposable)resource).Dispose(); }
// SPEC: }
// SPEC:
// SPEC: Otherwise, when ResourceType is dynamic, the expansion is:
// SPEC: {
// SPEC: dynamic resource = expr;
// SPEC: IDisposable d = (IDisposable)resource;
// SPEC: try { statement; }
// SPEC: finally { if (d != null) d.Dispose(); }
// SPEC: }
// SPEC:
// SPEC: An implementation is permitted to implement a given using statement
// SPEC: differently -- for example, for performance reasons -- as long as the
// SPEC: behavior is consistent with the above expansion.
//
// And we do in fact generate the code slightly differently than precisely how it is
// described above.
//
// First: if the type is a non-nullable value type then we do not do the
// *boxing conversion* from the resource to IDisposable. Rather, we do
// a *constrained virtual call* that elides the boxing if possible.
//
// Now, you might wonder if that is legal; isn't skipping the boxing producing
// an observable difference? Because if the value type is mutable and the Dispose
// mutates it, then skipping the boxing means that we are now mutating the original,
// not the boxed copy. But this is never observable. Either (1) we have "using(R r = x){}"
// and r is out of scope after the finally, so it is not possible to observe the mutation,
// or (2) we have "using(x) {}". But that has the semantics of "using(R temp = x){}",
// so again, we are not mutating x to begin with; we're always mutating a copy. Therefore
// it doesn't matter if we skip making *a copy of the copy*.
//
// This is what the dev10 compiler does, and we do so as well.
//
// Second: if the type is a nullable value type then we can similarly elide the boxing.
// We can generate
//
// {
// ResourceType resource = expr;
// try { statement; }
// finally { if (resource.HasValue) resource.GetValueOrDefault().Dispose(); }
// }
//
// Where again we do a constrained virtual call to Dispose, rather than boxing
// the value to IDisposable.
//
// Note that this optimization is *not* what the native compiler does; in this case
// the native compiler behavior is to test for HasValue, then *box* and convert
// the boxed value to IDisposable. There's no need to do that.
//
// Third: if we have "using(x)" and x is dynamic then obviously we need not generate
// "{ dynamic temp1 = x; IDisposable temp2 = (IDisposable) temp1; ... }". Rather, we elide
// the completely unnecessary first temporary.
BoundExpression disposedExpression;
bool isNullableValueType = local.Type.IsNullableType();
if (isNullableValueType)
{
MethodSymbol getValueOrDefault = GetNullableMethod(syntax, local.Type, SpecialMember.System_Nullable_T_GetValueOrDefault);
// local.GetValueOrDefault()
disposedExpression = BoundCall.Synthesized(syntax, local, getValueOrDefault);
}
else
{
// local
disposedExpression = local;
}
// local.Dispose()
BoundExpression disposeCall;
MethodSymbol disposeMethodSymbol;
if (TryGetSpecialTypeMember(syntax, SpecialMember.System_IDisposable__Dispose, out disposeMethodSymbol))
{
disposeCall = BoundCall.Synthesized(syntax, disposedExpression, disposeMethodSymbol);
}
else
{
disposeCall = new BoundBadExpression(syntax, LookupResultKind.NotInvocable, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(disposedExpression), ErrorTypeSymbol.UnknownResultType);
}
// local.Dispose();
BoundStatement disposeStatement = new BoundExpressionStatement(syntax, disposeCall);
BoundExpression ifCondition;
if (isNullableValueType)
{
MethodSymbol hasValue = GetNullableMethod(syntax, local.Type, SpecialMember.System_Nullable_T_get_HasValue);
// local.HasValue
ifCondition = BoundCall.Synthesized(syntax, local, hasValue);
}
else if (local.Type.IsValueType)
{
ifCondition = null;
}
else
{
// local != null
ifCondition = MakeNullCheck(syntax, local, BinaryOperatorKind.NotEqual);
}
BoundStatement finallyStatement;
if (ifCondition == null)
{
// local.Dispose();
finallyStatement = disposeStatement;
}
else
{
// if (local != null) local.Dispose();
// or
// if (local.HasValue) local.GetValueOrDefault().Dispose();
finallyStatement = RewriteIfStatement(
syntax: syntax,
locals: ImmutableArray<LocalSymbol>.Empty,
rewrittenCondition: ifCondition,
rewrittenConsequence: disposeStatement,
rewrittenAlternativeOpt: null,
hasErrors: false);
}
// try { ... } finally { if (local != null) local.Dispose(); }
BoundStatement tryFinally = new BoundTryStatement(
syntax: syntax,
tryBlock: tryBlock,
catchBlocks: ImmutableArray<BoundCatchBlock>.Empty,
finallyBlockOpt: BoundBlock.SynthesizedNoLocals(syntax, finallyStatement));
return tryFinally;
}
public BoundExpressionStatement BindExpressionStatement(CSharpSyntaxNode node, ExpressionSyntax syntax, bool allowsAnyExpression, DiagnosticBag diagnostics)
{
BoundExpressionStatement expressionStatement;
var expression = BindValue(syntax, diagnostics, BindValueKind.RValue);
if (!allowsAnyExpression && !IsValidStatementExpression(syntax, expression))
{
if (!node.HasErrors)
{
Error(diagnostics, ErrorCode.ERR_IllegalStatement, syntax);
}
expressionStatement = new BoundExpressionStatement(node, expression, hasErrors: true);
}
else
{
expressionStatement = new BoundExpressionStatement(node, expression);
}
CheckForUnobservedAwaitable(expressionStatement, diagnostics);
return expressionStatement;
}
private static BoundStatement RewriteFieldInitializer(BoundFieldEqualsValue fieldInit)
{
var syntax = fieldInit.Syntax;
syntax = (syntax as EqualsValueClauseSyntax)?.Value ?? syntax; //we want the attached sequence point to indicate the value node
var boundReceiver = fieldInit.Field.IsStatic ? null :
new BoundThisReference(syntax, fieldInit.Field.ContainingType);
#if XSHARP
var initValue = fieldInit.Value;
// a generated initial value for VO NULL_STRING initialization
// should not overwrite a value set in a child class
// not that we recommend that <g>
bool wasGenerated = fieldInit.WasCompilerGenerated;
if (!wasGenerated)
{
var xNode = initValue.Syntax as LiteralExpressionSyntax;
if (xNode != null && xNode.XGenerated)
{
wasGenerated = true;
}
}
if (wasGenerated && fieldInit.Field.Type.IsStringType() &&
boundReceiver != null &&
fieldInit.Field.DeclaringCompilation.Options.HasOption(CompilerOption.NullStrings, boundReceiver.Syntax))
{
var fldaccess = new BoundFieldAccess(syntax,
boundReceiver,
fieldInit.Field,
constantValueOpt: null)
{
WasCompilerGenerated = true
};
initValue = new BoundNullCoalescingOperator(syntax,
fldaccess,
initValue,
Conversion.Identity,
fieldInit.Field.Type)
{
WasCompilerGenerated = true
};
}
BoundStatement boundStatement =
new BoundExpressionStatement(syntax,
new BoundAssignmentOperator(syntax,
new BoundFieldAccess(syntax,
boundReceiver,
fieldInit.Field,
constantValueOpt: null),
initValue,
fieldInit.Field.Type)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = fieldInit.WasCompilerGenerated
};
#else
BoundStatement boundStatement =
new BoundExpressionStatement(syntax,
new BoundAssignmentOperator(syntax,
new BoundFieldAccess(syntax,
boundReceiver,
fieldInit.Field,
constantValueOpt: null),
fieldInit.Value,
fieldInit.Field.Type)
{
WasCompilerGenerated = true
})
{
WasCompilerGenerated = !fieldInit.Locals.IsEmpty || fieldInit.WasCompilerGenerated
};
#endif
if (!fieldInit.Locals.IsEmpty)
{
boundStatement = new BoundBlock(syntax, fieldInit.Locals, ImmutableArray.Create(boundStatement))
{
WasCompilerGenerated = fieldInit.WasCompilerGenerated
};
}
Debug.Assert(LocalRewriter.IsFieldOrPropertyInitializer(boundStatement));
return(boundStatement);
}
private static BoundInitializer BindGlobalStatement(Binder binder, StatementSyntax statementNode, DiagnosticBag diagnostics, bool isLast)
{
BoundStatement boundStatement = binder.BindStatement(statementNode, diagnostics);
// the result of the last global expression is assigned to the result storage for submission result:
if (binder.Compilation.IsSubmission && isLast && boundStatement.Kind == BoundKind.ExpressionStatement && !boundStatement.HasAnyErrors)
{
var submissionReturnType = binder.Compilation.GetSubmissionReturnType();
// insert an implicit conversion for the submission return type (if needed):
var expression = ((BoundExpressionStatement)boundStatement).Expression;
if ((object)expression.Type == null || expression.Type.SpecialType != SpecialType.System_Void)
{
expression = binder.GenerateConversionForAssignment(submissionReturnType, expression, diagnostics);
boundStatement = new BoundExpressionStatement(boundStatement.Syntax, expression, expression.HasErrors);
}
}
return new BoundGlobalStatementInitializer(statementNode, boundStatement);
}
public override BoundStatement InstrumentExpressionStatement(BoundExpressionStatement original, BoundStatement rewritten)
{
return(AddDynamicAnalysis(original, base.InstrumentExpressionStatement(original, rewritten)));
}
public override BoundNode VisitExpressionStatement(BoundExpressionStatement node)
{
// ref assignments might be translated away (into nothing). If so just
// return no statement. The enclosing statement list will just omit it.
BoundExpression expression = (BoundExpression)this.Visit(node.Expression);
return (expression == null) ? null : node.Update(expression);
}
/// <summary>
/// Lowers a lock statement to a try-finally block that calls Monitor.Enter and Monitor.Exit
/// before and after the body, respectively.
/// </summary>
public override BoundNode VisitLockStatement(BoundLockStatement node)
{
LockStatementSyntax lockSyntax = (LockStatementSyntax)node.Syntax;
BoundExpression rewrittenArgument = VisitExpression(node.Argument);
BoundStatement rewrittenBody = (BoundStatement)Visit(node.Body);
TypeSymbol argumentType = rewrittenArgument.Type;
if ((object)argumentType == null)
{
// This isn't particularly elegant, but hopefully locking on null is
// not very common.
Debug.Assert(rewrittenArgument.ConstantValue == ConstantValue.Null);
argumentType = this.compilation.GetSpecialType(SpecialType.System_Object);
rewrittenArgument = MakeLiteral(
rewrittenArgument.Syntax,
rewrittenArgument.ConstantValue,
argumentType); //need to have a non-null type here for TempHelpers.StoreToTemp.
}
if (argumentType.Kind == SymbolKind.TypeParameter)
{
// If the argument has a type parameter type, then we'll box it right away
// so that the same object is passed to both Monitor.Enter and Monitor.Exit.
argumentType = this.compilation.GetSpecialType(SpecialType.System_Object);
rewrittenArgument = MakeConversion(
rewrittenArgument.Syntax,
rewrittenArgument,
ConversionKind.Boxing,
argumentType,
@checked: false,
constantValueOpt: rewrittenArgument.ConstantValue);
}
BoundAssignmentOperator assignmentToLockTemp;
BoundLocal boundLockTemp = this.factory.StoreToTemp(rewrittenArgument, out assignmentToLockTemp, syntaxOpt: lockSyntax, kind: SynthesizedLocalKind.Lock);
BoundStatement boundLockTempInit = new BoundExpressionStatement(lockSyntax, assignmentToLockTemp);
BoundExpression exitCallExpr;
MethodSymbol exitMethod;
if (TryGetWellKnownTypeMember(lockSyntax, WellKnownMember.System_Threading_Monitor__Exit, out exitMethod))
{
exitCallExpr = BoundCall.Synthesized(
lockSyntax,
null,
exitMethod,
boundLockTemp);
}
else
{
exitCallExpr = new BoundBadExpression(lockSyntax, LookupResultKind.NotInvocable, ImmutableArray <Symbol> .Empty, ImmutableArray.Create <BoundNode>(boundLockTemp), ErrorTypeSymbol.UnknownResultType);
}
BoundStatement exitCall = new BoundExpressionStatement(lockSyntax, exitCallExpr);
MethodSymbol enterMethod;
if ((TryGetWellKnownTypeMember(lockSyntax, WellKnownMember.System_Threading_Monitor__Enter2, out enterMethod, isOptional: true) ||
TryGetWellKnownTypeMember(lockSyntax, WellKnownMember.System_Threading_Monitor__Enter, out enterMethod)) && // If we didn't find the overload introduced in .NET 4.0, then use the older one.
enterMethod.ParameterCount == 2)
{
// C# 4.0+ version
// L $lock = `argument`; // sequence point
// bool $lockTaken = false;
// try
// {
// Monitor.Enter($lock, ref $lockTaken);
// `body` // sequence point
// }
// finally
// { // hidden sequence point
// if ($lockTaken) Monitor.Exit($lock);
// }
TypeSymbol boolType = this.compilation.GetSpecialType(SpecialType.System_Boolean);
BoundAssignmentOperator assignmentToLockTakenTemp;
BoundLocal boundLockTakenTemp = this.factory.StoreToTemp(
MakeLiteral(rewrittenArgument.Syntax, ConstantValue.False, boolType),
store: out assignmentToLockTakenTemp,
syntaxOpt: lockSyntax,
kind: SynthesizedLocalKind.LockTaken);
BoundStatement boundLockTakenTempInit = new BoundExpressionStatement(lockSyntax, assignmentToLockTakenTemp);
BoundStatement enterCall = new BoundExpressionStatement(
lockSyntax,
BoundCall.Synthesized(
lockSyntax,
null,
enterMethod,
boundLockTemp,
boundLockTakenTemp));
exitCall = RewriteIfStatement(
lockSyntax,
boundLockTakenTemp,
exitCall,
null,
node.HasErrors);
return(new BoundBlock(
lockSyntax,
ImmutableArray.Create(boundLockTemp.LocalSymbol, boundLockTakenTemp.LocalSymbol),
ImmutableArray.Create(
MakeInitialLockSequencePoint(boundLockTempInit, lockSyntax),
boundLockTakenTempInit,
new BoundTryStatement(
lockSyntax,
BoundBlock.SynthesizedNoLocals(lockSyntax, ImmutableArray.Create(
enterCall,
rewrittenBody)),
ImmutableArray <BoundCatchBlock> .Empty,
BoundBlock.SynthesizedNoLocals(lockSyntax,
exitCall)))));
}
else
{
// Pre-4.0 version
// L $lock = `argument`; // sequence point
// Monitor.Enter($lock); // NB: before try-finally so we don't Exit if an exception prevents us from acquiring the lock.
// try
// {
// `body` // sequence point
// }
// finally
// {
// Monitor.Exit($lock); // hidden sequence point
// }
BoundExpression enterCallExpr;
if ((object)enterMethod != null)
{
Debug.Assert(enterMethod.ParameterCount == 1);
enterCallExpr = BoundCall.Synthesized(
lockSyntax,
null,
enterMethod,
boundLockTemp);
}
else
{
enterCallExpr = new BoundBadExpression(lockSyntax, LookupResultKind.NotInvocable, ImmutableArray <Symbol> .Empty, ImmutableArray.Create <BoundNode>(boundLockTemp), ErrorTypeSymbol.UnknownResultType);
}
BoundStatement enterCall = new BoundExpressionStatement(
lockSyntax,
enterCallExpr);
return(new BoundBlock(
lockSyntax,
ImmutableArray.Create(boundLockTemp.LocalSymbol),
ImmutableArray.Create(
MakeInitialLockSequencePoint(boundLockTempInit, lockSyntax),
enterCall,
new BoundTryStatement(
lockSyntax,
BoundBlock.SynthesizedNoLocals(lockSyntax, rewrittenBody),
ImmutableArray <BoundCatchBlock> .Empty,
BoundBlock.SynthesizedNoLocals(lockSyntax, exitCall)))));
}
}
/// <summary>
/// Lowers a lock statement to a try-finally block that calls Monitor.Enter and Monitor.Exit
/// before and after the body, respectively.
///
/// C# 4.0 version
///
/// L locked;
/// bool flag = false;
/// try {
/// locked = `argument`;
/// Monitor.Enter(locked, ref flag);
/// `body`
/// } finally {
/// if (flag) Monitor.Exit(locked);
/// }
///
/// Pre-4.0 version
///
/// L locked = `argument`;
/// Monitor.Enter(locked, ref flag);
/// try {
/// `body`
/// } finally {
/// Monitor.Exit(locked);
/// }
/// </summary>
public override BoundNode VisitLockStatement(BoundLockStatement node)
{
LockStatementSyntax lockSyntax = (LockStatementSyntax)node.Syntax;
BoundExpression rewrittenArgument = VisitExpression(node.Argument);
BoundStatement rewrittenBody = (BoundStatement)Visit(node.Body);
TypeSymbol argumentType = rewrittenArgument.Type;
if ((object)argumentType == null)
{
// This isn't particularly elegant, but hopefully locking on null is
// not very common.
Debug.Assert(rewrittenArgument.ConstantValue == ConstantValue.Null);
argumentType = this.compilation.GetSpecialType(SpecialType.System_Object);
rewrittenArgument = MakeLiteral(
rewrittenArgument.Syntax,
rewrittenArgument.ConstantValue,
argumentType); //need to have a non-null type here for TempHelpers.StoreToTemp.
}
if (argumentType.Kind == SymbolKind.TypeParameter)
{
// If the argument has a type parameter type, then we'll box it right away
// so that the same object is passed to both Monitor.Enter and Monitor.Exit.
argumentType = this.compilation.GetSpecialType(SpecialType.System_Object);
rewrittenArgument = MakeConversion(
rewrittenArgument.Syntax,
rewrittenArgument,
ConversionKind.Boxing,
argumentType,
@checked: false,
constantValueOpt: rewrittenArgument.ConstantValue);
}
BoundAssignmentOperator assignmentToLockTemp;
BoundLocal boundLockTemp = this.factory.StoreToTemp(rewrittenArgument, out assignmentToLockTemp, kind: SynthesizedLocalKind.Lock);
BoundStatement boundLockTempInit = new BoundExpressionStatement(lockSyntax, assignmentToLockTemp);
if (this.GenerateDebugInfo)
{
boundLockTempInit = new BoundSequencePointWithSpan( // NOTE: the lock temp is uninitialized at this sequence point.
lockSyntax,
boundLockTempInit,
TextSpan.FromBounds(lockSyntax.LockKeyword.SpanStart, lockSyntax.CloseParenToken.Span.End));
}
BoundExpression exitCallExpr;
MethodSymbol exitMethod;
if (TryGetWellKnownTypeMember(lockSyntax, WellKnownMember.System_Threading_Monitor__Exit, out exitMethod))
{
exitCallExpr = BoundCall.Synthesized(
lockSyntax,
null,
exitMethod,
boundLockTemp);
}
else
{
exitCallExpr = new BoundBadExpression(lockSyntax, LookupResultKind.NotInvocable, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(boundLockTemp), ErrorTypeSymbol.UnknownResultType);
}
BoundStatement exitCall = new BoundExpressionStatement(
lockSyntax,
exitCallExpr);
MethodSymbol enterMethod;
if ((TryGetWellKnownTypeMember(lockSyntax, WellKnownMember.System_Threading_Monitor__Enter2, out enterMethod, isOptional: true) ||
TryGetWellKnownTypeMember(lockSyntax, WellKnownMember.System_Threading_Monitor__Enter, out enterMethod)) && // If we didn't find the overload introduced in .NET 4.0, then use the older one.
enterMethod.ParameterCount == 2)
{
// C# 4.0 version
// L locked;
// bool flag = false;
// try {
// locked = `argument`;
// Monitor.Enter(locked, ref flag);
// `body`
// } finally {
// if (flag) Monitor.Exit(locked);
// }
TypeSymbol boolType = this.compilation.GetSpecialType(SpecialType.System_Boolean);
BoundAssignmentOperator assignmentToTemp;
BoundLocal boundFlagTemp = this.factory.StoreToTemp(
MakeLiteral(rewrittenArgument.Syntax, ConstantValue.False, boolType),
kind: SynthesizedLocalKind.LockTaken,
store: out assignmentToTemp);
BoundStatement boundFlagTempInit = new BoundExpressionStatement(lockSyntax, assignmentToTemp);
if (this.GenerateDebugInfo)
{
// hide the preamble code, we should not stop until we get to " locked = `argument`; "
boundFlagTempInit = new BoundSequencePoint(null, boundFlagTempInit);
}
BoundStatement enterCall = new BoundExpressionStatement(
lockSyntax,
BoundCall.Synthesized(
lockSyntax,
null,
enterMethod,
boundLockTemp,
boundFlagTemp));
exitCall = RewriteIfStatement(
lockSyntax,
ImmutableArray<LocalSymbol>.Empty,
boundFlagTemp,
exitCall,
null,
node.HasErrors);
return new BoundBlock(
lockSyntax,
node.Locals.Concat(ImmutableArray.Create<LocalSymbol>(boundLockTemp.LocalSymbol, boundFlagTemp.LocalSymbol)),
ImmutableArray.Create<BoundStatement>(
boundFlagTempInit,
new BoundTryStatement(
lockSyntax,
BoundBlock.SynthesizedNoLocals(lockSyntax, boundLockTempInit, enterCall, rewrittenBody),
ImmutableArray<BoundCatchBlock>.Empty,
BoundBlock.SynthesizedNoLocals(lockSyntax, exitCall))));
}
else
{
BoundExpression enterCallExpr;
if ((object)enterMethod != null)
{
Debug.Assert(enterMethod.ParameterCount == 1);
// Pre-4.0 version
// L locked = `argument`;
// Monitor.Enter(locked, ref flag); //NB: before try-finally so we don't Exit if an exception prevents us from acquiring the lock.
// try {
// `body`
// } finally {
// Monitor.Exit(locked);
// }
enterCallExpr = BoundCall.Synthesized(
lockSyntax,
null,
enterMethod,
boundLockTemp);
}
else
{
enterCallExpr = new BoundBadExpression(lockSyntax, LookupResultKind.NotInvocable, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(boundLockTemp), ErrorTypeSymbol.UnknownResultType);
}
BoundStatement enterCall = new BoundExpressionStatement(
lockSyntax,
enterCallExpr);
return new BoundBlock(
lockSyntax,
node.Locals.Add(boundLockTemp.LocalSymbol),
ImmutableArray.Create<BoundStatement>(
boundLockTempInit,
enterCall,
new BoundTryStatement(
lockSyntax,
BoundBlock.SynthesizedNoLocals(lockSyntax, rewrittenBody),
ImmutableArray<BoundCatchBlock>.Empty,
BoundBlock.SynthesizedNoLocals(lockSyntax, exitCall))));
}
}
/// <summary>
/// Lower a foreach loop that will enumerate a collection using an enumerator.
///
/// E e = ((C)(x)).GetEnumerator()
/// try {
/// while (e.MoveNext()) {
/// V v = (V)(T)e.Current;
/// // body
/// }
/// }
/// finally {
/// // clean up e
/// }
/// </summary>
private BoundStatement RewriteEnumeratorForEachStatement(BoundForEachStatement node)
{
ForEachStatementSyntax forEachSyntax = (ForEachStatementSyntax)node.Syntax;
ForEachEnumeratorInfo enumeratorInfo = node.EnumeratorInfoOpt;
Debug.Assert(enumeratorInfo != null);
BoundExpression collectionExpression = GetUnconvertedCollectionExpression(node);
BoundExpression rewrittenExpression = (BoundExpression)Visit(collectionExpression);
BoundStatement rewrittenBody = (BoundStatement)Visit(node.Body);
TypeSymbol enumeratorType = enumeratorInfo.GetEnumeratorMethod.ReturnType;
TypeSymbol elementType = enumeratorInfo.ElementType;
// E e
LocalSymbol enumeratorVar = _factory.SynthesizedLocal(enumeratorType, syntax: forEachSyntax, kind: SynthesizedLocalKind.ForEachEnumerator);
// Reference to e.
BoundLocal boundEnumeratorVar = MakeBoundLocal(forEachSyntax, enumeratorVar, enumeratorType);
// ((C)(x)).GetEnumerator() or (x).GetEnumerator();
BoundExpression enumeratorVarInitValue = SynthesizeCall(forEachSyntax, rewrittenExpression, enumeratorInfo.GetEnumeratorMethod, enumeratorInfo.CollectionConversion, enumeratorInfo.CollectionType);
// E e = ((C)(x)).GetEnumerator();
BoundStatement enumeratorVarDecl = MakeLocalDeclaration(forEachSyntax, enumeratorVar, enumeratorVarInitValue);
AddForEachExpressionSequencePoint(forEachSyntax, ref enumeratorVarDecl);
// V v
LocalSymbol iterationVar = node.IterationVariable;
//(V)(T)e.Current
BoundExpression iterationVarAssignValue = MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundEnumeratorVar,
method: enumeratorInfo.CurrentPropertyGetter),
conversion: enumeratorInfo.CurrentConversion,
rewrittenType: elementType,
@checked: node.Checked),
conversion: node.ElementConversion,
rewrittenType: iterationVar.Type,
@checked: node.Checked);
// V v = (V)(T)e.Current;
BoundStatement iterationVarDecl = MakeLocalDeclaration(forEachSyntax, iterationVar, iterationVarAssignValue);
AddForEachIterationVariableSequencePoint(forEachSyntax, ref iterationVarDecl);
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* node.Body */
// }
BoundStatement whileLoop = RewriteWhileStatement(
syntax: forEachSyntax,
rewrittenCondition: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundEnumeratorVar,
method: enumeratorInfo.MoveNextMethod),
conditionSequencePointSpan: forEachSyntax.InKeyword.Span,
rewrittenBody: new BoundBlock(rewrittenBody.Syntax,
statements: ImmutableArray.Create <BoundStatement>(iterationVarDecl, rewrittenBody),
locals: ImmutableArray.Create <LocalSymbol>(iterationVar)),
breakLabel: node.BreakLabel,
continueLabel: node.ContinueLabel,
hasErrors: false);
BoundStatement result;
MethodSymbol disposeMethod;
if (enumeratorInfo.NeedsDisposeMethod && Binder.TryGetSpecialTypeMember(_compilation, SpecialMember.System_IDisposable__Dispose, forEachSyntax, _diagnostics, out disposeMethod))
{
Binder.ReportDiagnosticsIfObsolete(_diagnostics, disposeMethod, forEachSyntax,
hasBaseReceiver: false,
containingMember: _factory.CurrentMethod,
containingType: _factory.CurrentType,
location: enumeratorInfo.Location);
BoundBlock finallyBlockOpt;
var idisposableTypeSymbol = disposeMethod.ContainingType;
var conversions = new TypeConversions(_factory.CurrentMethod.ContainingAssembly.CorLibrary);
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
var isImplicit = conversions.ClassifyImplicitConversion(enumeratorType, idisposableTypeSymbol, ref useSiteDiagnostics).IsImplicit;
_diagnostics.Add(forEachSyntax, useSiteDiagnostics);
if (isImplicit)
{
Debug.Assert(enumeratorInfo.NeedsDisposeMethod);
Conversion receiverConversion = enumeratorType.IsStructType() ?
Conversion.Boxing :
Conversion.ImplicitReference;
// ((IDisposable)e).Dispose(); or e.Dispose();
BoundStatement disposeCall = new BoundExpressionStatement(forEachSyntax,
expression: SynthesizeCall(forEachSyntax, boundEnumeratorVar, disposeMethod, receiverConversion, idisposableTypeSymbol));
BoundStatement disposeStmt;
if (enumeratorType.IsValueType)
{
// No way for the struct to be nullable and disposable.
Debug.Assert(((TypeSymbol)enumeratorType.OriginalDefinition).SpecialType != SpecialType.System_Nullable_T);
// For non-nullable structs, no null check is required.
disposeStmt = disposeCall;
}
else
{
// NB: cast to object missing from spec. Needed to ignore user-defined operators and box type parameters.
// if ((object)e != null) ((IDisposable)e).Dispose();
disposeStmt = RewriteIfStatement(
syntax: forEachSyntax,
rewrittenCondition: new BoundBinaryOperator(forEachSyntax,
operatorKind: BinaryOperatorKind.NotEqual,
left: MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: boundEnumeratorVar,
conversion: enumeratorInfo.EnumeratorConversion,
rewrittenType: _compilation.GetSpecialType(SpecialType.System_Object),
@checked: false),
right: MakeLiteral(forEachSyntax,
constantValue: ConstantValue.Null,
type: null),
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: _compilation.GetSpecialType(SpecialType.System_Boolean)),
rewrittenConsequence: disposeCall,
rewrittenAlternativeOpt: null,
hasErrors: false);
}
finallyBlockOpt = new BoundBlock(forEachSyntax,
locals: ImmutableArray <LocalSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(disposeStmt));
}
else
{
Debug.Assert(!enumeratorType.IsSealed);
// IDisposable d
LocalSymbol disposableVar = _factory.SynthesizedLocal(idisposableTypeSymbol);
// Reference to d.
BoundLocal boundDisposableVar = MakeBoundLocal(forEachSyntax, disposableVar, idisposableTypeSymbol);
BoundTypeExpression boundIDisposableTypeExpr = new BoundTypeExpression(forEachSyntax,
aliasOpt: null,
type: idisposableTypeSymbol);
// e as IDisposable
BoundExpression disposableVarInitValue = new BoundAsOperator(forEachSyntax,
operand: boundEnumeratorVar,
targetType: boundIDisposableTypeExpr,
conversion: Conversion.ExplicitReference, // Explicit so the emitter won't optimize it away.
type: idisposableTypeSymbol);
// IDisposable d = e as IDisposable;
BoundStatement disposableVarDecl = MakeLocalDeclaration(forEachSyntax, disposableVar, disposableVarInitValue);
// if (d != null) d.Dispose();
BoundStatement ifStmt = RewriteIfStatement(
syntax: forEachSyntax,
rewrittenCondition: new BoundBinaryOperator(forEachSyntax,
operatorKind: BinaryOperatorKind.NotEqual, // reference equality
left: boundDisposableVar,
right: MakeLiteral(forEachSyntax,
constantValue: ConstantValue.Null,
type: null),
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: _compilation.GetSpecialType(SpecialType.System_Boolean)),
rewrittenConsequence: new BoundExpressionStatement(forEachSyntax,
expression: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundDisposableVar,
method: disposeMethod)),
rewrittenAlternativeOpt: null,
hasErrors: false);
// IDisposable d = e as IDisposable;
// if (d != null) d.Dispose();
finallyBlockOpt = new BoundBlock(forEachSyntax,
locals: ImmutableArray.Create <LocalSymbol>(disposableVar),
statements: ImmutableArray.Create <BoundStatement>(disposableVarDecl, ifStmt));
}
// try {
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* loop body */
// }
// }
// finally {
// /* dispose of e */
// }
BoundStatement tryFinally = new BoundTryStatement(forEachSyntax,
tryBlock: new BoundBlock(forEachSyntax,
locals: ImmutableArray <LocalSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(whileLoop)),
catchBlocks: ImmutableArray <BoundCatchBlock> .Empty,
finallyBlockOpt: finallyBlockOpt);
// E e = ((C)(x)).GetEnumerator();
// try {
// /* as above */
result = new BoundBlock(
syntax: forEachSyntax,
locals: ImmutableArray.Create(enumeratorVar),
statements: ImmutableArray.Create <BoundStatement>(enumeratorVarDecl, tryFinally));
}
else
{
// E e = ((C)(x)).GetEnumerator();
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* loop body */
// }
result = new BoundBlock(
syntax: forEachSyntax,
locals: ImmutableArray.Create(enumeratorVar),
statements: ImmutableArray.Create <BoundStatement>(enumeratorVarDecl, whileLoop));
}
AddForEachKeywordSequencePoint(forEachSyntax, ref result);
return(result);
}
private BoundStatement MakeSwitchStatementWithNullableExpression(
CSharpSyntaxNode syntax,
BoundExpression rewrittenExpression,
ImmutableArray<BoundSwitchSection> rewrittenSections,
LabelSymbol constantTargetOpt,
ImmutableArray<LocalSymbol> locals,
GeneratedLabelSymbol breakLabel,
BoundSwitchStatement oldNode)
{
Debug.Assert(rewrittenExpression.Type.IsNullableType());
var exprSyntax = rewrittenExpression.Syntax;
var exprNullableType = rewrittenExpression.Type;
var statementBuilder = ArrayBuilder<BoundStatement>.GetInstance();
// Rewrite the nullable expression to a temp as we might have a user defined conversion from source expression to switch governing type.
// We can avoid generating the temp if the expression is a bound local.
LocalSymbol tempLocal;
if (rewrittenExpression.Kind != BoundKind.Local)
{
BoundAssignmentOperator assignmentToTemp;
BoundLocal boundTemp = _factory.StoreToTemp(rewrittenExpression, out assignmentToTemp);
var tempAssignment = new BoundExpressionStatement(exprSyntax, assignmentToTemp);
statementBuilder.Add(tempAssignment);
tempLocal = boundTemp.LocalSymbol;
rewrittenExpression = boundTemp;
}
else
{
tempLocal = null;
}
// Generate a BoundConditionalGoto with null check as the conditional expression and appropriate switch label as the target: null, default or exit label.
BoundStatement condGotoNullValueTargetLabel = new BoundConditionalGoto(
exprSyntax,
condition: MakeNullCheck(exprSyntax, rewrittenExpression, BinaryOperatorKind.NullableNullEqual),
jumpIfTrue: true,
label: GetNullValueTargetSwitchLabel(rewrittenSections, breakLabel));
// Rewrite the switch statement using nullable expression's underlying value as the switch expression.
// rewrittenExpression.GetValueOrDefault()
MethodSymbol getValueOrDefault = GetNullableMethod(syntax, exprNullableType, SpecialMember.System_Nullable_T_GetValueOrDefault);
BoundCall callGetValueOrDefault = BoundCall.Synthesized(exprSyntax, rewrittenExpression, getValueOrDefault);
rewrittenExpression = callGetValueOrDefault;
// rewrite switch statement
BoundStatement rewrittenSwitchStatement = MakeSwitchStatementWithNonNullableExpression(
syntax,
condGotoNullValueTargetLabel,
rewrittenExpression,
rewrittenSections,
constantTargetOpt,
locals,
breakLabel,
oldNode);
statementBuilder.Add(rewrittenSwitchStatement);
return new BoundBlock(syntax, locals: (object)tempLocal == null ? ImmutableArray<LocalSymbol>.Empty : ImmutableArray.Create<LocalSymbol>(tempLocal), statements: statementBuilder.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>
/// Lower "using (expression) statement" to a try-finally block.
/// </summary>
private BoundBlock RewriteExpressionUsingStatement(BoundUsingStatement node, BoundBlock tryBlock)
{
Debug.Assert(node.ExpressionOpt != null);
Debug.Assert(node.DeclarationsOpt == null);
// See comments in BuildUsingTryFinally for the details of the lowering to try-finally.
//
// SPEC: A using statement of the form "using (expression) statement; " has the
// SPEC: same three possible expansions [ as "using (ResourceType r = expression) statement; ]
// SPEC: but in this case ResourceType is implicitly the compile-time type of the expression,
// SPEC: and the resource variable is inaccessible to and invisible to the embedded statement.
//
// DELIBERATE SPEC VIOLATION:
//
// The spec quote above implies that the expression must have a type; in fact we allow
// the expression to be null.
//
// If expr is the constant null then we can elide the whole thing and simply generate the statement.
BoundExpression rewrittenExpression = (BoundExpression)Visit(node.ExpressionOpt);
if (rewrittenExpression.ConstantValue == ConstantValue.Null)
{
Debug.Assert(node.Locals.IsEmpty); // TODO: This might not be a valid assumption in presence of semicolon operator.
return tryBlock;
}
// Otherwise, we lower "using(expression) statement;" as follows:
//
// * If the expression is of type dynamic then we lower as though the user had written
//
// using(IDisposable temp = (IDisposable)expression) statement;
//
// Note that we have to do the conversion early, not in the finally block, because
// if the conversion fails at runtime with an exception then the exception must happen
// before the statement runs.
//
// * Otherwise we lower as though the user had written
//
// using(ResourceType temp = expression) statement;
//
TypeSymbol expressionType = rewrittenExpression.Type;
CSharpSyntaxNode expressionSyntax = rewrittenExpression.Syntax;
UsingStatementSyntax usingSyntax = (UsingStatementSyntax)node.Syntax;
BoundAssignmentOperator tempAssignment;
BoundLocal boundTemp;
if ((object)expressionType == null || expressionType.IsDynamic())
{
// IDisposable temp = (IDisposable) expr;
BoundExpression tempInit = MakeConversion(
expressionSyntax,
rewrittenExpression,
node.IDisposableConversion.Kind,
this.compilation.GetSpecialType(SpecialType.System_IDisposable),
@checked: false,
constantValueOpt: rewrittenExpression.ConstantValue);
boundTemp = this.factory.StoreToTemp(tempInit, out tempAssignment);
}
else
{
// ResourceType temp = expr;
boundTemp = this.factory.StoreToTemp(rewrittenExpression, out tempAssignment, kind: SynthesizedLocalKind.Using);
}
BoundStatement expressionStatement = new BoundExpressionStatement(expressionSyntax, tempAssignment);
if (this.generateDebugInfo)
{
expressionStatement = AddSequencePoint(usingSyntax, expressionStatement);
}
BoundStatement tryFinally = RewriteUsingStatementTryFinally(usingSyntax, tryBlock, boundTemp);
// { ResourceType temp = expr; try { ... } finally { ... } }
return new BoundBlock(
syntax: usingSyntax,
locals: node.Locals.Add(boundTemp.LocalSymbol),
statements: ImmutableArray.Create<BoundStatement>(expressionStatement, tryFinally));
}
/// <summary>
/// Prepares most of the parts for MoveNextAsync() and DisposeAsync() methods.
/// </summary>
private void GetPartsForStartingMachine(TypeSymbol returnType, out BoundExpressionStatement callReset, out LocalSymbol instSymbol,
out BoundStatement instAssignment, out BoundExpressionStatement startCall, out MethodSymbol promise_get_Version)
{
// Produce the following parts:
// - _promiseOfValueOrEnd.Reset();
// - var inst = this;
// - _builder.Start(ref inst);
// - _valueOrEndPromise.Version
// _promiseOfValueOrEnd.Reset();
BoundFieldAccess promiseField = F.InstanceField(_promiseOfValueOrEndField);
var resetMethod = (MethodSymbol)F.WellKnownMethod(WellKnownMember.System_Threading_Tasks_Sources_ManualResetValueTaskSourceCore_T__Reset, isOptional: true)
.SymbolAsMember((NamedTypeSymbol)_promiseOfValueOrEndField.Type.TypeSymbol);
callReset = F.ExpressionStatement(F.Call(promiseField, resetMethod));
// _builder.Start(ref inst);
Debug.Assert(!_asyncMethodBuilderMemberCollection.CheckGenericMethodConstraints);
MethodSymbol startMethod = _asyncMethodBuilderMemberCollection.Start.Construct(this.stateMachineType);
instSymbol = F.SynthesizedLocal(this.stateMachineType);
// var inst = this;
var instLocal = F.Local(instSymbol);
instAssignment = F.Assignment(instLocal, F.This());
// _builder.Start(ref inst);
startCall = F.ExpressionStatement(
F.Call(
F.InstanceField(_builderField),
startMethod,
ImmutableArray.Create <BoundExpression>(instLocal)));
// _valueOrEndPromise.Version
promise_get_Version = F.WellKnownMethod(WellKnownMember.System_Threading_Tasks_Sources_ManualResetValueTaskSourceCore_T__get_Version)
.AsMember((NamedTypeSymbol)_promiseOfValueOrEndField.Type.TypeSymbol);
}
