/// <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, RefKind.None, 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(BoundBlock.SynthesizedNoLocals(syntax, statement));
}
public override BoundNode VisitReturnStatement(BoundReturnStatement node)
{
BoundStatement rewritten = (BoundStatement)base.VisitReturnStatement(node);
// NOTE: we will apply sequence points to synthesized return
// statements if they are contained in lambdas and have expressions
// or if they are expression-bodied properties.
// We do this to ensure that expression lambdas and expression-bodied
// properties have sequence points.
// We also add sequence points for the implicit "return" statement at the end of the method body
// (added by FlowAnalysisPass.AppendImplicitReturn). Implicitly added return for async method
// does not need sequence points added here since it would be done later (presumably during Async rewrite).
if (this.Instrument &&
(!node.WasCompilerGenerated ||
(node.ExpressionOpt != null ?
IsLambdaOrExpressionBodiedMember :
(node.Syntax.Kind() == SyntaxKind.Block && _factory.CurrentMethod?.IsAsync == false))))
{
rewritten = _instrumenter.InstrumentReturnStatement(node, rewritten);
}
else if (node.WasCompilerGenerated && _factory.CurrentMethod?.IsAsync == true)
{
rewritten = new BoundSequencePoint(null, rewritten);
}
return(rewritten);
}
private BoundStatement RewriteWhileStatement(
BoundLoopStatement loop,
BoundExpression rewrittenCondition,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
Debug.Assert(loop.Kind == BoundKind.WhileStatement || loop.Kind == BoundKind.ForEachStatement);
// while (condition)
// body;
//
// becomes
//
// goto continue;
// start:
// {
// body
// continue:
// GotoIfTrue condition start;
// }
// break:
SyntaxNode syntax = loop.Syntax;
var startLabel = new GeneratedLabelSymbol("start");
BoundStatement ifConditionGotoStart = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
BoundStatement gotoContinue = new BoundGotoStatement(syntax, continueLabel);
if (this.Instrument && !loop.WasCompilerGenerated)
{
switch (loop.Kind)
{
case BoundKind.WhileStatement:
ifConditionGotoStart = _instrumenter.InstrumentWhileStatementConditionalGotoStartOrBreak((BoundWhileStatement)loop, ifConditionGotoStart);
break;
case BoundKind.ForEachStatement:
ifConditionGotoStart = _instrumenter.InstrumentForEachStatementConditionalGotoStart((BoundForEachStatement)loop, ifConditionGotoStart);
break;
default:
throw ExceptionUtilities.UnexpectedValue(loop.Kind);
}
// mark the initial jump as hidden. We do it to tell that this is not a part of previous statement. This
// jump may be a target of another jump (for example if loops are nested) and that would give the
// impression that the previous statement is being re-executed.
gotoContinue = new BoundSequencePoint(null, gotoContinue);
}
return(BoundStatementList.Synthesized(syntax, hasErrors,
gotoContinue,
new BoundLabelStatement(syntax, startLabel),
rewrittenBody,
new BoundLabelStatement(syntax, continueLabel),
ifConditionGotoStart,
new BoundLabelStatement(syntax, breakLabel)));
}
private BoundStatement RewriteWhileStatement(
BoundLoopStatement loop,
BoundExpression rewrittenCondition,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
Debug.Assert(loop.Kind == BoundKind.WhileStatement || loop.Kind == BoundKind.ForEachStatement);
// while (condition)
// body;
//
// becomes
//
// goto continue;
// start:
// {
// body
// continue:
// GotoIfTrue condition start;
// }
// break:
SyntaxNode syntax = loop.Syntax;
var startLabel = new GeneratedLabelSymbol("start");
BoundStatement ifConditionGotoStart = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
BoundStatement gotoContinue = new BoundGotoStatement(syntax, continueLabel);
if (this.Instrument && !loop.WasCompilerGenerated)
{
switch (loop.Kind)
{
case BoundKind.WhileStatement:
ifConditionGotoStart = _instrumenter.InstrumentWhileStatementConditionalGotoStartOrBreak((BoundWhileStatement)loop, ifConditionGotoStart);
break;
case BoundKind.ForEachStatement:
ifConditionGotoStart = _instrumenter.InstrumentForEachStatementConditionalGotoStart((BoundForEachStatement)loop, ifConditionGotoStart);
break;
default:
throw ExceptionUtilities.UnexpectedValue(loop.Kind);
}
// mark the initial jump as hidden. We do it to tell that this is not a part of previous statement. This
// jump may be a target of another jump (for example if loops are nested) and that would give the
// impression that the previous statement is being re-executed.
gotoContinue = new BoundSequencePoint(null, gotoContinue);
}
return BoundStatementList.Synthesized(syntax, hasErrors,
gotoContinue,
new BoundLabelStatement(syntax, startLabel),
rewrittenBody,
new BoundLabelStatement(syntax, continueLabel),
ifConditionGotoStart,
new BoundLabelStatement(syntax, breakLabel));
}
private BoundStatement AddSequencePoint(BoundStatement node)
{
if (this.GenerateDebugInfo && !node.WasCompilerGenerated)
{
node = new BoundSequencePoint(node.Syntax, node);
}
return(node);
}
/// <summary>
/// Add sequence point |here|:
///
/// foreach (Type var in |expr|) { }
/// </summary>
/// <remarks>
/// Hit once, before looping begins.
/// </remarks>
private void AddForEachExpressionSequencePoint(ForEachStatementSyntax forEachSyntax, ref BoundStatement collectionVarDecl)
{
if (this.GenerateDebugInfo)
{
// NOTE: This is slightly different from Dev10. In Dev10, when you stop the debugger
// on the collection expression, you can see the (uninitialized) iteration variable.
// In Roslyn, you cannot because the iteration variable is re-declared in each iteration
// of the loop and is, therefore, not yet in scope.
collectionVarDecl = new BoundSequencePoint(forEachSyntax.Expression, collectionVarDecl);
}
}
internal static BoundStatement AddSequencePoint(VariableDeclaratorSyntax declaratorSyntax, BoundStatement rewrittenStatement)
{
SyntaxNode node;
TextSpan? part;
GetBreakpointSpan(declaratorSyntax, out node, out part);
var result = BoundSequencePoint.Create(declaratorSyntax, part, rewrittenStatement);
result.WasCompilerGenerated = rewrittenStatement.WasCompilerGenerated;
return(result);
}
internal static BoundStatement AddSequencePoint(PropertyDeclarationSyntax declarationSyntax, BoundStatement rewrittenStatement)
{
Debug.Assert(declarationSyntax.Initializer != null);
int start = declarationSyntax.Initializer.Value.SpanStart;
int end = declarationSyntax.Initializer.Span.End;
TextSpan part = TextSpan.FromBounds(start, end);
var result = BoundSequencePoint.Create(declarationSyntax, part, rewrittenStatement);
result.WasCompilerGenerated = rewrittenStatement.WasCompilerGenerated;
return(result);
}
internal static BoundStatement AddSequencePoint(PropertyDeclarationSyntax declarationSyntax, BoundStatement rewrittenStatement)
{
SyntaxTokenList modifiers = declarationSyntax.Modifiers;
// Skip attributes
int start = modifiers.Any() ? modifiers[0].SpanStart : declarationSyntax.Type.SpanStart;
int end = declarationSyntax.Span.End;
TextSpan part = TextSpan.FromBounds(start, end);
var result = BoundSequencePoint.Create(declarationSyntax, part, rewrittenStatement);
result.WasCompilerGenerated = rewrittenStatement.WasCompilerGenerated;
return(result);
}
private BoundStatement RewriteWhileStatement(
BoundWhileStatement loop,
ImmutableArray <LocalSymbol> locals,
BoundExpression rewrittenCondition,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
if (locals.IsEmpty)
{
return(RewriteWhileStatement(loop, rewrittenCondition, rewrittenBody, breakLabel, continueLabel, hasErrors));
}
// We need to enter scope-block from the top, that is where an instance of a display class will be created
// if any local is captured within a lambda.
// while (condition)
// body;
//
// becomes
//
// continue:
// {
// GotoIfFalse condition break;
// body
// goto continue;
// }
// break:
SyntaxNode syntax = loop.Syntax;
BoundStatement continueLabelStatement = new BoundLabelStatement(syntax, continueLabel);
BoundStatement ifNotConditionGotoBreak = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, breakLabel);
if (this.Instrument && !loop.WasCompilerGenerated)
{
ifNotConditionGotoBreak = _instrumenter.InstrumentWhileStatementConditionalGotoStartOrBreak(loop, ifNotConditionGotoBreak);
continueLabelStatement = new BoundSequencePoint(null, continueLabelStatement);
}
return(BoundStatementList.Synthesized(syntax, hasErrors,
continueLabelStatement,
new BoundBlock(syntax,
locals,
ImmutableArray.Create(
ifNotConditionGotoBreak,
rewrittenBody,
new BoundGotoStatement(syntax, continueLabel))),
new BoundLabelStatement(syntax, breakLabel)));
}
private BoundStatement RewriteWhileStatement(
CSharpSyntaxNode syntax,
BoundExpression rewrittenCondition,
TextSpan conditionSequencePointSpan,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
var startLabel = new GeneratedLabelSymbol("start");
BoundStatement ifConditionGotoStart = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
if (this.GenerateDebugInfo)
{
ifConditionGotoStart = new BoundSequencePointWithSpan(syntax, ifConditionGotoStart, conditionSequencePointSpan);
}
// while (condition)
// body;
//
// becomes
//
// goto continue;
// start:
// {
// body
// continue:
// GotoIfTrue condition start;
// }
// break:
BoundStatement gotoContinue = new BoundGotoStatement(syntax, continueLabel);
if (this.GenerateDebugInfo)
{
// mark the initial jump as hidden. We do it to tell that this is not a part of previous statement. This
// jump may be a target of another jump (for example if loops are nested) and that would give the
// impression that the previous statement is being re-executed.
gotoContinue = new BoundSequencePoint(null, gotoContinue);
}
return(BoundStatementList.Synthesized(syntax, hasErrors,
gotoContinue,
new BoundLabelStatement(syntax, startLabel),
rewrittenBody,
new BoundLabelStatement(syntax, continueLabel),
ifConditionGotoStart,
new BoundLabelStatement(syntax, breakLabel)));
}
private BoundStatement RewriteWhileStatement(
CSharpSyntaxNode syntax,
BoundExpression rewrittenCondition,
TextSpan conditionSequencePointSpan,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
var startLabel = new GeneratedLabelSymbol("start");
BoundStatement ifConditionGotoStart = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
if (this.GenerateDebugInfo)
{
ifConditionGotoStart = new BoundSequencePointWithSpan(syntax, ifConditionGotoStart, conditionSequencePointSpan);
}
// while (condition)
// body;
//
// becomes
//
// goto continue;
// start:
// {
// body
// continue:
// GotoIfTrue condition start;
// }
// break:
BoundStatement gotoContinue = new BoundGotoStatement(syntax, continueLabel);
if (this.GenerateDebugInfo)
{
// mark the initial jump as hidden. We do it to tell that this is not a part of previous statement. This
// jump may be a target of another jump (for example if loops are nested) and that would give the
// impression that the previous statement is being re-executed.
gotoContinue = new BoundSequencePoint(null, gotoContinue);
}
return BoundStatementList.Synthesized(syntax, hasErrors,
gotoContinue,
new BoundLabelStatement(syntax, startLabel),
rewrittenBody,
new BoundLabelStatement(syntax, continueLabel),
ifConditionGotoStart,
new BoundLabelStatement(syntax, breakLabel));
}
private BoundStatement RewriteForStatement(
BoundForStatement node,
BoundStatement rewrittenInitializer,
BoundExpression rewrittenCondition,
BoundStatement rewrittenIncrement,
BoundStatement rewrittenBody)
{
if (node.InnerLocals.IsEmpty)
{
return(RewriteForStatementWithoutInnerLocals(
node,
node.OuterLocals,
rewrittenInitializer,
rewrittenCondition,
rewrittenIncrement,
rewrittenBody,
node.BreakLabel,
node.ContinueLabel, node.HasErrors));
}
// We need to enter inner_scope-block from the top, that is where an instance of a display class will be created
// if any local is captured within a lambda.
// for (initializer; condition; increment)
// body;
//
// becomes the following (with block added for locals)
//
// {
// initializer;
// start:
// {
// GotoIfFalse condition break;
// body;
// continue:
// increment;
// goto start;
// }
// break:
// }
Debug.Assert(rewrittenBody != null);
SyntaxNode syntax = node.Syntax;
var statementBuilder = ArrayBuilder <BoundStatement> .GetInstance();
// initializer;
if (rewrittenInitializer != null)
{
statementBuilder.Add(rewrittenInitializer);
}
var startLabel = new GeneratedLabelSymbol("start");
// start:
BoundStatement startLabelStatement = new BoundLabelStatement(syntax, startLabel);
if (Instrument)
{
startLabelStatement = new BoundSequencePoint(null, startLabelStatement);
}
statementBuilder.Add(startLabelStatement);
var blockBuilder = ArrayBuilder <BoundStatement> .GetInstance();
// GotoIfFalse condition break;
if (rewrittenCondition != null)
{
BoundStatement ifNotConditionGotoBreak = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, node.BreakLabel);
if (this.Instrument)
{
ifNotConditionGotoBreak = _instrumenter.InstrumentForStatementConditionalGotoStartOrBreak(node, ifNotConditionGotoBreak);
}
blockBuilder.Add(ifNotConditionGotoBreak);
}
// body;
blockBuilder.Add(rewrittenBody);
// continue:
// increment;
blockBuilder.Add(new BoundLabelStatement(syntax, node.ContinueLabel));
if (rewrittenIncrement != null)
{
blockBuilder.Add(rewrittenIncrement);
}
// goto start;
blockBuilder.Add(new BoundGotoStatement(syntax, startLabel));
statementBuilder.Add(new BoundBlock(syntax, node.InnerLocals, blockBuilder.ToImmutableAndFree()));
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, node.BreakLabel));
var statements = statementBuilder.ToImmutableAndFree();
return(new BoundBlock(syntax, node.OuterLocals, statements, node.HasErrors));
}
/// <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))));
}
}
private BoundStatement RewriteWhileStatement(
BoundWhileStatement loop,
ImmutableArray<LocalSymbol> locals,
BoundExpression rewrittenCondition,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
if (locals.IsEmpty)
{
return RewriteWhileStatement(loop, rewrittenCondition, rewrittenBody, breakLabel, continueLabel, hasErrors);
}
// We need to enter scope-block from the top, that is where an instance of a display class will be created
// if any local is captured within a lambda.
// while (condition)
// body;
//
// becomes
//
// continue:
// {
// GotoIfFalse condition break;
// body
// goto continue;
// }
// break:
SyntaxNode syntax = loop.Syntax;
BoundStatement continueLabelStatement = new BoundLabelStatement(syntax, continueLabel);
BoundStatement ifNotConditionGotoBreak = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, breakLabel);
if (this.Instrument && !loop.WasCompilerGenerated)
{
ifNotConditionGotoBreak = _instrumenter.InstrumentWhileStatementConditionalGotoStartOrBreak(loop, ifNotConditionGotoBreak);
continueLabelStatement = new BoundSequencePoint(null, continueLabelStatement);
}
return BoundStatementList.Synthesized(syntax, hasErrors,
continueLabelStatement,
new BoundBlock(syntax,
locals,
ImmutableArray.Create(
ifNotConditionGotoBreak,
rewrittenBody,
new BoundGotoStatement(syntax, continueLabel))),
new BoundLabelStatement(syntax, breakLabel));
}
private BoundStatement RewriteForStatement(
BoundForStatement node,
BoundStatement rewrittenInitializer,
BoundExpression rewrittenCondition,
BoundStatement rewrittenIncrement,
BoundStatement rewrittenBody)
{
if (node.InnerLocals.IsEmpty)
{
return RewriteForStatementWithoutInnerLocals(
node,
node.OuterLocals,
rewrittenInitializer,
rewrittenCondition,
rewrittenIncrement,
rewrittenBody,
node.BreakLabel,
node.ContinueLabel, node.HasErrors);
}
// We need to enter inner_scope-block from the top, that is where an instance of a display class will be created
// if any local is captured within a lambda.
// for (initializer; condition; increment)
// body;
//
// becomes the following (with block added for locals)
//
// {
// initializer;
// start:
// {
// GotoIfFalse condition break;
// body;
// continue:
// increment;
// goto start;
// }
// break:
// }
Debug.Assert(rewrittenBody != null);
SyntaxNode syntax = node.Syntax;
var statementBuilder = ArrayBuilder<BoundStatement>.GetInstance();
// initializer;
if (rewrittenInitializer != null)
{
statementBuilder.Add(rewrittenInitializer);
}
var startLabel = new GeneratedLabelSymbol("start");
// start:
BoundStatement startLabelStatement = new BoundLabelStatement(syntax, startLabel);
if (Instrument)
{
startLabelStatement = new BoundSequencePoint(null, startLabelStatement);
}
statementBuilder.Add(startLabelStatement);
var blockBuilder = ArrayBuilder<BoundStatement>.GetInstance();
// GotoIfFalse condition break;
if (rewrittenCondition != null)
{
BoundStatement ifNotConditionGotoBreak = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, node.BreakLabel);
if (this.Instrument)
{
ifNotConditionGotoBreak = _instrumenter.InstrumentForStatementConditionalGotoStartOrBreak(node, ifNotConditionGotoBreak);
}
blockBuilder.Add(ifNotConditionGotoBreak);
}
// body;
blockBuilder.Add(rewrittenBody);
// continue:
// increment;
blockBuilder.Add(new BoundLabelStatement(syntax, node.ContinueLabel));
if (rewrittenIncrement != null)
{
blockBuilder.Add(rewrittenIncrement);
}
// goto start;
blockBuilder.Add(new BoundGotoStatement(syntax, startLabel));
statementBuilder.Add(new BoundBlock(syntax, node.InnerLocals, blockBuilder.ToImmutableAndFree()));
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, node.BreakLabel));
var statements = statementBuilder.ToImmutableAndFree();
return new BoundBlock(syntax, node.OuterLocals, statements, node.HasErrors);
}
private BoundStatement RewriteWhileStatement(
CSharpSyntaxNode syntax,
ImmutableArray <LocalSymbol> innerLocals,
BoundExpression rewrittenCondition,
TextSpan conditionSequencePointSpan,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
if (!innerLocals.IsDefaultOrEmpty)
{
var walker = new AnyLocalCapturedInALambdaWalker(innerLocals);
if (walker.Analyze(rewrittenCondition) || walker.Analyze(rewrittenBody))
{
// If any inner local is captured within a lambda, we need to enter scope-block
// always from the top, that is where an instance of a display class will be created.
// The IL will be less optimal, but this shouldn't be a problem, given presence of lambdas.
// while (condition)
// body;
//
// becomes
//
// continue:
// {
// GotoIfFalse condition break;
// body
// goto continue;
// }
// break:
// TODO: We could perform more fine analysis.
// If locals declared in condition (the innerLocals) are captured, but not referenced in the body, we could use optimal IL by creating
// another block around the condition and use it as a scope for the locals declared in condition.
// This optimization can be applied to 'for' as well, while-body === for-body + increment.
// Note however that the scope adjusments will likely be observable during debugging, in locals window.
BoundStatement ifNotConditionGotoBreak = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, breakLabel);
if (this.generateDebugInfo)
{
ifNotConditionGotoBreak = new BoundSequencePointWithSpan(syntax, ifNotConditionGotoBreak, conditionSequencePointSpan);
}
return(BoundStatementList.Synthesized(syntax, hasErrors,
new BoundLabelStatement(syntax, continueLabel),
new BoundBlock(syntax,
innerLocals,
ImmutableArray.Create <BoundStatement>(
ifNotConditionGotoBreak,
rewrittenBody,
new BoundGotoStatement(syntax, continueLabel))),
new BoundLabelStatement(syntax, breakLabel)));
}
}
var startLabel = new GeneratedLabelSymbol("start");
BoundStatement ifConditionGotoStart = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
if (this.generateDebugInfo)
{
ifConditionGotoStart = new BoundSequencePointWithSpan(syntax, ifConditionGotoStart, conditionSequencePointSpan);
}
// while (condition)
// body;
//
// becomes
//
// goto continue;
// start:
// {
// body
// continue:
// GotoIfTrue condition start;
// }
// break:
BoundStatement gotoContinue = new BoundGotoStatement(syntax, continueLabel);
if (this.generateDebugInfo)
{
// mark the initial jump as hidden. We do it to tell that this is not a part of previous statement. This
// jump may be a target of another jump (for example if loops are nested) and that would give the
// impression that the previous statement is being re-executed.
gotoContinue = new BoundSequencePoint(null, gotoContinue);
}
if (!innerLocals.IsDefaultOrEmpty)
{
return(BoundStatementList.Synthesized(syntax, hasErrors,
gotoContinue,
new BoundLabelStatement(syntax, startLabel),
new BoundBlock(syntax,
innerLocals,
ImmutableArray.Create <BoundStatement>(
rewrittenBody,
new BoundLabelStatement(syntax, continueLabel),
ifConditionGotoStart)),
new BoundLabelStatement(syntax, breakLabel)));
}
return(BoundStatementList.Synthesized(syntax, hasErrors,
gotoContinue,
new BoundLabelStatement(syntax, startLabel),
rewrittenBody,
new BoundLabelStatement(syntax, continueLabel),
ifConditionGotoStart,
new BoundLabelStatement(syntax, breakLabel)));
}
private BoundStatement RewriteForStatement(
CSharpSyntaxNode syntax,
ImmutableArray <LocalSymbol> outerLocals,
BoundStatement rewrittenInitializer,
ImmutableArray <LocalSymbol> innerLocals,
BoundExpression rewrittenCondition,
SyntaxNodeOrToken conditionSyntax,
BoundStatement rewrittenIncrement,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
Debug.Assert(rewrittenBody != null);
// The sequence point behavior exhibited here is different from that of the native compiler. In the native
// compiler, if you have something like
//
// for(int i = 0, j = 0; ; i++, j++)
// ^--------------^ ^------^
//
// then all the initializers are treated as a single sequence point, as are
// all the loop incrementers.
//
// We now make each one individually a sequence point:
//
// for(int i = 0, j = 0; ; i++, j++)
// ^-------^ ^---^ ^-^ ^-^
//
// If we decide that we want to preserve the native compiler stepping behavior
// then we'll need to be a bit fancy here. The initializer and increment statements
// can contain lambdas whose bodies need to have sequence points inserted, so we
// need to make sure we visit the children. But we'll also need to make sure that
// we do not generate one sequence point for each statement in the initializers
// and the incrementers.
var statementBuilder = ArrayBuilder <BoundStatement> .GetInstance();
if (rewrittenInitializer != null)
{
statementBuilder.Add(rewrittenInitializer);
}
var startLabel = new GeneratedLabelSymbol("start");
if (!innerLocals.IsDefaultOrEmpty)
{
var walker = new AnyLocalCapturedInALambdaWalker(innerLocals);
if (walker.Analyze(rewrittenCondition) || walker.Analyze(rewrittenIncrement) || walker.Analyze(rewrittenBody))
{
// If any inner local is captured within a lambda, we need to enter scope-block
// always from the top, that is where an instance of a display class will be created.
// The IL will be less optimal, but this shouldn't be a problem, given presence of lambdas.
// for (initializer; condition; increment)
// body;
//
// becomes the following (with
// block added for locals)
//
// {
// initializer;
// start:
// {
// GotoIfFalse condition break;
// body;
// continue:
// increment;
// goto start;
// }
// break:
// }
// start:
statementBuilder.Add(new BoundLabelStatement(syntax, startLabel));
var blockBuilder = ArrayBuilder <BoundStatement> .GetInstance();
// GotoIfFalse condition break;
if (rewrittenCondition != null)
{
BoundStatement ifNotConditionGotoBreak = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, breakLabel);
if (this.generateDebugInfo)
{
if (conditionSyntax.IsToken)
{
ifNotConditionGotoBreak = new BoundSequencePointWithSpan(syntax, ifNotConditionGotoBreak, conditionSyntax.Span);
}
else
{
ifNotConditionGotoBreak = new BoundSequencePoint((CSharpSyntaxNode)conditionSyntax.AsNode(), ifNotConditionGotoBreak);
}
}
blockBuilder.Add(ifNotConditionGotoBreak);
}
// body;
blockBuilder.Add(rewrittenBody);
// continue:
// increment;
blockBuilder.Add(new BoundLabelStatement(syntax, continueLabel));
if (rewrittenIncrement != null)
{
blockBuilder.Add(rewrittenIncrement);
}
// goto start;
blockBuilder.Add(new BoundGotoStatement(syntax, startLabel));
statementBuilder.Add(new BoundBlock(syntax, innerLocals, blockBuilder.ToImmutableAndFree()));
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, breakLabel));
return(new BoundBlock(syntax, outerLocals, statementBuilder.ToImmutableAndFree(), hasErrors));
}
}
var endLabel = new GeneratedLabelSymbol("end");
// for (initializer; condition; increment)
// body;
//
// becomes the following (with
// block added for locals)
//
// {
// initializer;
// goto end;
// start:
// body;
// continue:
// increment;
// end:
// GotoIfTrue condition start;
// break:
// }
// initializer;
// goto end;
//mark the initial jump as hidden.
//We do it to tell that this is not a part of previous statement.
//This jump may be a target of another jump (for example if loops are nested) and that will make
//impression of the previous statement being re-executed
var gotoEnd = new BoundSequencePoint(null, new BoundGotoStatement(syntax, endLabel));
statementBuilder.Add(gotoEnd);
// start:
// body;
statementBuilder.Add(new BoundLabelStatement(syntax, startLabel));
ArrayBuilder <BoundStatement> saveBuilder = null;
if (!innerLocals.IsDefaultOrEmpty)
{
saveBuilder = statementBuilder;
statementBuilder = ArrayBuilder <BoundStatement> .GetInstance();
}
statementBuilder.Add(rewrittenBody);
// continue:
// increment;
statementBuilder.Add(new BoundLabelStatement(syntax, continueLabel));
if (rewrittenIncrement != null)
{
statementBuilder.Add(rewrittenIncrement);
}
// end:
// GotoIfTrue condition start;
statementBuilder.Add(new BoundLabelStatement(syntax, endLabel));
BoundStatement branchBack = null;
if (rewrittenCondition != null)
{
branchBack = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
}
else
{
branchBack = new BoundGotoStatement(syntax, startLabel);
}
if (this.generateDebugInfo)
{
if (conditionSyntax.IsToken)
{
branchBack = new BoundSequencePointWithSpan(syntax, branchBack, conditionSyntax.Span);
}
else
{
//if there is no condition, make this a hidden point so that
//it does not count as a part of previous statement
branchBack = new BoundSequencePoint((CSharpSyntaxNode)conditionSyntax.AsNode(), branchBack);
}
}
statementBuilder.Add(branchBack);
if (!innerLocals.IsDefaultOrEmpty)
{
var block = new BoundBlock(syntax, innerLocals, statementBuilder.ToImmutableAndFree());
statementBuilder = saveBuilder;
statementBuilder.Add(block);
}
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, breakLabel));
var statements = statementBuilder.ToImmutableAndFree();
return(new BoundBlock(syntax, outerLocals, statements, hasErrors));
}
private BoundStatement RewriteForStatement(
CSharpSyntaxNode syntax,
ImmutableArray<LocalSymbol> outerLocals,
BoundStatement rewrittenInitializer,
BoundExpression rewrittenCondition,
CSharpSyntaxNode conditionSyntaxOpt,
TextSpan conditionSpanOpt,
BoundStatement rewrittenIncrement,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
Debug.Assert(rewrittenBody != null);
// The sequence point behavior exhibited here is different from that of the native compiler. In the native
// compiler, if you have something like
//
// for([|int i = 0, j = 0|]; ; [|i++, j++|])
//
// then all the initializers are treated as a single sequence point, as are
// all the loop incrementors.
//
// We now make each one individually a sequence point:
//
// for([|int i = 0|], [|j = 0|]; ; [|i++|], [|j++|])
//
// If we decide that we want to preserve the native compiler stepping behavior
// then we'll need to be a bit fancy here. The initializer and increment statements
// can contain lambdas whose bodies need to have sequence points inserted, so we
// need to make sure we visit the children. But we'll also need to make sure that
// we do not generate one sequence point for each statement in the initializers
// and the incrementors.
var statementBuilder = ArrayBuilder<BoundStatement>.GetInstance();
if (rewrittenInitializer != null)
{
statementBuilder.Add(rewrittenInitializer);
}
var startLabel = new GeneratedLabelSymbol("start");
// for (initializer; condition; increment)
// body;
//
// becomes the following (with block added for locals)
//
// {
// initializer;
// goto end;
// start:
// body;
// continue:
// increment;
// end:
// GotoIfTrue condition start;
// break:
// }
var endLabel = new GeneratedLabelSymbol("end");
// initializer;
// goto end;
// Mark the initial jump as hidden.
// We do it to tell that this is not a part of previous statement.
// This jump may be a target of another jump (for example if loops are nested) and that will make
// impression of the previous statement being re-executed
var gotoEnd = new BoundSequencePoint(null, new BoundGotoStatement(syntax, endLabel));
statementBuilder.Add(gotoEnd);
// start:
// body;
statementBuilder.Add(new BoundLabelStatement(syntax, startLabel));
statementBuilder.Add(rewrittenBody);
// continue:
// increment;
statementBuilder.Add(new BoundLabelStatement(syntax, continueLabel));
if (rewrittenIncrement != null)
{
statementBuilder.Add(rewrittenIncrement);
}
// end:
// GotoIfTrue condition start;
statementBuilder.Add(new BoundLabelStatement(syntax, endLabel));
BoundStatement branchBack = null;
if (rewrittenCondition != null)
{
branchBack = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
}
else
{
branchBack = new BoundGotoStatement(syntax, startLabel);
}
if (this.GenerateDebugInfo)
{
if (!conditionSpanOpt.IsEmpty)
{
branchBack = new BoundSequencePointWithSpan(syntax, branchBack, conditionSpanOpt);
}
else
{
// hidden sequence point if there is no condition
branchBack = new BoundSequencePoint(conditionSyntaxOpt, branchBack);
}
}
statementBuilder.Add(branchBack);
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, breakLabel));
var statements = statementBuilder.ToImmutableAndFree();
return new BoundBlock(syntax, outerLocals, statements, hasErrors);
}
/// <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, tempKind: TempKind.Lock, store: out assignmentToLockTemp);
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),
tempKind: TempKind.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,
boundFlagTemp,
exitCall,
null,
node.HasErrors);
return(new BoundBlock(
lockSyntax,
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,
ImmutableArray.Create <LocalSymbol>(boundLockTemp.LocalSymbol),
ImmutableArray.Create <BoundStatement>(
boundLockTempInit,
enterCall,
new BoundTryStatement(
lockSyntax,
BoundBlock.SynthesizedNoLocals(lockSyntax, rewrittenBody),
ImmutableArray <BoundCatchBlock> .Empty,
BoundBlock.SynthesizedNoLocals(lockSyntax, exitCall)))));
}
}
/// <summary>
/// Add sequence point |here|:
///
/// foreach (Type var in |expr|) { }
/// </summary>
/// <remarks>
/// Hit once, before looping begins.
/// </remarks>
private void AddForEachExpressionSequencePoint(ForEachStatementSyntax forEachSyntax, ref BoundStatement collectionVarDecl)
{
if (this.GenerateDebugInfo)
{
// NOTE: This is slightly different from Dev10. In Dev10, when you stop the debugger
// on the collection expression, you can see the (uninitialized) iteration variable.
// In Roslyn, you cannot because the iteration variable is re-declared in each iteration
// of the loop and is, therefore, not yet in scope.
collectionVarDecl = new BoundSequencePoint(forEachSyntax.Expression, collectionVarDecl);
}
}
/// <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, ImmutableArray<LocalSymbol>.Empty, ImmutableArray.Create<BoundStatement>(statement)) { WasCompilerGenerated = true };
}
private BoundStatement RewriteForStatement(
CSharpSyntaxNode syntax,
ImmutableArray <LocalSymbol> outerLocals,
BoundStatement rewrittenInitializer,
BoundExpression rewrittenCondition,
CSharpSyntaxNode conditionSyntaxOpt,
TextSpan conditionSpanOpt,
BoundStatement rewrittenIncrement,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
Debug.Assert(rewrittenBody != null);
// The sequence point behavior exhibited here is different from that of the native compiler. In the native
// compiler, if you have something like
//
// for([|int i = 0, j = 0|]; ; [|i++, j++|])
//
// then all the initializers are treated as a single sequence point, as are
// all the loop incrementers.
//
// We now make each one individually a sequence point:
//
// for([|int i = 0|], [|j = 0|]; ; [|i++|], [|j++|])
//
// If we decide that we want to preserve the native compiler stepping behavior
// then we'll need to be a bit fancy here. The initializer and increment statements
// can contain lambdas whose bodies need to have sequence points inserted, so we
// need to make sure we visit the children. But we'll also need to make sure that
// we do not generate one sequence point for each statement in the initializers
// and the incrementers.
var statementBuilder = ArrayBuilder <BoundStatement> .GetInstance();
if (rewrittenInitializer != null)
{
statementBuilder.Add(rewrittenInitializer);
}
var startLabel = new GeneratedLabelSymbol("start");
// for (initializer; condition; increment)
// body;
//
// becomes the following (with block added for locals)
//
// {
// initializer;
// goto end;
// start:
// body;
// continue:
// increment;
// end:
// GotoIfTrue condition start;
// break:
// }
var endLabel = new GeneratedLabelSymbol("end");
// initializer;
// goto end;
// Mark the initial jump as hidden.
// We do it to tell that this is not a part of previous statement.
// This jump may be a target of another jump (for example if loops are nested) and that will make
// impression of the previous statement being re-executed
var gotoEnd = new BoundSequencePoint(null, new BoundGotoStatement(syntax, endLabel));
statementBuilder.Add(gotoEnd);
// start:
// body;
statementBuilder.Add(new BoundLabelStatement(syntax, startLabel));
statementBuilder.Add(rewrittenBody);
// continue:
// increment;
statementBuilder.Add(new BoundLabelStatement(syntax, continueLabel));
if (rewrittenIncrement != null)
{
statementBuilder.Add(rewrittenIncrement);
}
// end:
// GotoIfTrue condition start;
statementBuilder.Add(new BoundLabelStatement(syntax, endLabel));
BoundStatement branchBack = null;
if (rewrittenCondition != null)
{
branchBack = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
}
else
{
branchBack = new BoundGotoStatement(syntax, startLabel);
}
if (this.GenerateDebugInfo)
{
if (!conditionSpanOpt.IsEmpty)
{
branchBack = new BoundSequencePointWithSpan(syntax, branchBack, conditionSpanOpt);
}
else
{
// hidden sequence point if there is no condition
branchBack = new BoundSequencePoint(conditionSyntaxOpt, branchBack);
}
}
statementBuilder.Add(branchBack);
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, breakLabel));
var statements = statementBuilder.ToImmutableAndFree();
return(new BoundBlock(syntax, outerLocals, statements, hasErrors));
}
private BoundStatement RewriteWhileStatement(
CSharpSyntaxNode syntax,
ImmutableArray<LocalSymbol> innerLocals,
BoundExpression rewrittenCondition,
TextSpan conditionSequencePointSpan,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
if (!innerLocals.IsDefaultOrEmpty)
{
var walker = new AnyLocalCapturedInALambdaWalker(innerLocals);
if (walker.Analyze(rewrittenCondition) || walker.Analyze(rewrittenBody))
{
// If any inner local is captured within a lambda, we need to enter scope-block
// always from the top, that is where an instance of a display class will be created.
// The IL will be less optimal, but this shouldn't be a problem, given presence of lambdas.
// while (condition)
// body;
//
// becomes
//
// continue:
// {
// GotoIfFalse condition break;
// body
// goto continue;
// }
// break:
// TODO: We could perform more fine analysis.
// If locals declared in condition (the innerLocals) are captured, but not referenced in the body, we could use optimal IL by creating
// another block around the condition and use it as a scope for the locals declared in condition.
// This optimization can be applied to 'for' as well, while-body === for-body + increment.
// Note however that the scope adjusments will likely be observable during debugging, in locals window.
BoundStatement ifNotConditionGotoBreak = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, breakLabel);
if (this.GenerateDebugInfo)
{
ifNotConditionGotoBreak = new BoundSequencePointWithSpan(syntax, ifNotConditionGotoBreak, conditionSequencePointSpan);
}
return BoundStatementList.Synthesized(syntax, hasErrors,
new BoundLabelStatement(syntax, continueLabel),
new BoundBlock(syntax,
innerLocals,
ImmutableArray.Create(
ifNotConditionGotoBreak,
rewrittenBody,
new BoundGotoStatement(syntax, continueLabel))),
new BoundLabelStatement(syntax, breakLabel));
}
}
var startLabel = new GeneratedLabelSymbol("start");
BoundStatement ifConditionGotoStart = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
if (this.GenerateDebugInfo)
{
ifConditionGotoStart = new BoundSequencePointWithSpan(syntax, ifConditionGotoStart, conditionSequencePointSpan);
}
// while (condition)
// body;
//
// becomes
//
// goto continue;
// start:
// {
// body
// continue:
// GotoIfTrue condition start;
// }
// break:
BoundStatement gotoContinue = new BoundGotoStatement(syntax, continueLabel);
if (this.GenerateDebugInfo)
{
// mark the initial jump as hidden. We do it to tell that this is not a part of previous statement. This
// jump may be a target of another jump (for example if loops are nested) and that would give the
// impression that the previous statement is being re-executed.
gotoContinue = new BoundSequencePoint(null, gotoContinue);
}
if (!innerLocals.IsDefaultOrEmpty)
{
return BoundStatementList.Synthesized(syntax, hasErrors,
gotoContinue,
new BoundLabelStatement(syntax, startLabel),
new BoundBlock(syntax,
innerLocals,
ImmutableArray.Create<BoundStatement>(
rewrittenBody,
new BoundLabelStatement(syntax, continueLabel),
ifConditionGotoStart)),
new BoundLabelStatement(syntax, breakLabel));
}
return BoundStatementList.Synthesized(syntax, hasErrors,
gotoContinue,
new BoundLabelStatement(syntax, startLabel),
rewrittenBody,
new BoundLabelStatement(syntax, continueLabel),
ifConditionGotoStart,
new BoundLabelStatement(syntax, breakLabel));
}
private BoundStatement RewriteForStatement(
CSharpSyntaxNode syntax,
ImmutableArray<LocalSymbol> outerLocals,
BoundStatement rewrittenInitializer,
ImmutableArray<LocalSymbol> innerLocals,
BoundExpression rewrittenCondition,
SyntaxNodeOrToken conditionSyntax,
BoundStatement rewrittenIncrement,
BoundStatement rewrittenBody,
GeneratedLabelSymbol breakLabel,
GeneratedLabelSymbol continueLabel,
bool hasErrors)
{
Debug.Assert(rewrittenBody != null);
// The sequence point behavior exhibited here is different from that of the native compiler. In the native
// compiler, if you have something like
//
// for(int i = 0, j = 0; ; i++, j++)
// ^--------------^ ^------^
//
// then all the initializers are treated as a single sequence point, as are
// all the loop incrementers.
//
// We now make each one individually a sequence point:
//
// for(int i = 0, j = 0; ; i++, j++)
// ^-------^ ^---^ ^-^ ^-^
//
// If we decide that we want to preserve the native compiler stepping behavior
// then we'll need to be a bit fancy here. The initializer and increment statements
// can contain lambdas whose bodies need to have sequence points inserted, so we
// need to make sure we visit the children. But we'll also need to make sure that
// we do not generate one sequence point for each statement in the initializers
// and the incrementers.
var statementBuilder = ArrayBuilder<BoundStatement>.GetInstance();
if (rewrittenInitializer != null)
{
statementBuilder.Add(rewrittenInitializer);
}
var startLabel = new GeneratedLabelSymbol("start");
if (!innerLocals.IsDefaultOrEmpty)
{
var walker = new AnyLocalCapturedInALambdaWalker(innerLocals);
if (walker.Analyze(rewrittenCondition) || walker.Analyze(rewrittenIncrement) || walker.Analyze(rewrittenBody))
{
// If any inner local is captured within a lambda, we need to enter scope-block
// always from the top, that is where an instance of a display class will be created.
// The IL will be less optimal, but this shouldn't be a problem, given presence of lambdas.
// for (initializer; condition; increment)
// body;
//
// becomes the following (with
// block added for locals)
//
// {
// initializer;
// start:
// {
// GotoIfFalse condition break;
// body;
// continue:
// increment;
// goto start;
// }
// break:
// }
// start:
statementBuilder.Add(new BoundLabelStatement(syntax, startLabel));
var blockBuilder = ArrayBuilder<BoundStatement>.GetInstance();
// GotoIfFalse condition break;
if (rewrittenCondition != null)
{
BoundStatement ifNotConditionGotoBreak = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, breakLabel);
if (this.generateDebugInfo)
{
if (conditionSyntax.IsToken)
{
ifNotConditionGotoBreak = new BoundSequencePointWithSpan(syntax, ifNotConditionGotoBreak, conditionSyntax.Span);
}
else
{
ifNotConditionGotoBreak = new BoundSequencePoint((CSharpSyntaxNode)conditionSyntax.AsNode(), ifNotConditionGotoBreak);
}
}
blockBuilder.Add(ifNotConditionGotoBreak);
}
// body;
blockBuilder.Add(rewrittenBody);
// continue:
// increment;
blockBuilder.Add(new BoundLabelStatement(syntax, continueLabel));
if (rewrittenIncrement != null)
{
blockBuilder.Add(rewrittenIncrement);
}
// goto start;
blockBuilder.Add(new BoundGotoStatement(syntax, startLabel));
statementBuilder.Add(new BoundBlock(syntax, innerLocals, blockBuilder.ToImmutableAndFree()));
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, breakLabel));
return new BoundBlock(syntax, outerLocals, statementBuilder.ToImmutableAndFree(), hasErrors);
}
}
var endLabel = new GeneratedLabelSymbol("end");
// for (initializer; condition; increment)
// body;
//
// becomes the following (with
// block added for locals)
//
// {
// initializer;
// goto end;
// start:
// body;
// continue:
// increment;
// end:
// GotoIfTrue condition start;
// break:
// }
// initializer;
// goto end;
//mark the initial jump as hidden.
//We do it to tell that this is not a part of previous statement.
//This jump may be a target of another jump (for example if loops are nested) and that will make
//impression of the previous statement being re-executed
var gotoEnd = new BoundSequencePoint(null, new BoundGotoStatement(syntax, endLabel));
statementBuilder.Add(gotoEnd);
// start:
// body;
statementBuilder.Add(new BoundLabelStatement(syntax, startLabel));
ArrayBuilder<BoundStatement> saveBuilder = null;
if (!innerLocals.IsDefaultOrEmpty)
{
saveBuilder = statementBuilder;
statementBuilder = ArrayBuilder<BoundStatement>.GetInstance();
}
statementBuilder.Add(rewrittenBody);
// continue:
// increment;
statementBuilder.Add(new BoundLabelStatement(syntax, continueLabel));
if (rewrittenIncrement != null)
{
statementBuilder.Add(rewrittenIncrement);
}
// end:
// GotoIfTrue condition start;
statementBuilder.Add(new BoundLabelStatement(syntax, endLabel));
BoundStatement branchBack = null;
if (rewrittenCondition != null)
{
branchBack = new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, true, startLabel);
}
else
{
branchBack = new BoundGotoStatement(syntax, startLabel);
}
if (this.generateDebugInfo)
{
if (conditionSyntax.IsToken)
{
branchBack = new BoundSequencePointWithSpan(syntax, branchBack, conditionSyntax.Span);
}
else
{
//if there is no condition, make this a hidden point so that
//it does not count as a part of previous statement
branchBack = new BoundSequencePoint((CSharpSyntaxNode)conditionSyntax.AsNode(), branchBack);
}
}
statementBuilder.Add(branchBack);
if (!innerLocals.IsDefaultOrEmpty)
{
var block = new BoundBlock(syntax, innerLocals, statementBuilder.ToImmutableAndFree());
statementBuilder = saveBuilder;
statementBuilder.Add(block);
}
// break:
statementBuilder.Add(new BoundLabelStatement(syntax, breakLabel));
var statements = statementBuilder.ToImmutableAndFree();
return new BoundBlock(syntax, outerLocals, statements, hasErrors);
}