public override bool VisitMemberReferenceExpression(MemberReferenceExpression memberReferenceExpression, object data)
{
bool result = base.VisitMemberReferenceExpression(memberReferenceExpression, data);
UnaryOperatorExpression uoe = memberReferenceExpression.Target as UnaryOperatorExpression;
if (uoe != null && uoe.Operator == UnaryOperatorType.Dereference)
{
PointerReferenceExpression pre = new PointerReferenceExpression();
pre.Target = uoe.Expression.Detach();
pre.MemberNameToken = (Identifier)memberReferenceExpression.MemberNameToken.Clone();
memberReferenceExpression.TypeArguments.MoveTo(pre.TypeArguments);
pre.CopyAnnotationsFrom(uoe);
pre.CopyAnnotationsFrom(memberReferenceExpression);
pre.AddAnnotation(memberReferenceExpression.GetAllRecursiveILRanges());
memberReferenceExpression.ReplaceWith(pre);
}
return(result);
}
public override object VisitBlockStatement(BlockStatement blockStatement, object data)
{
int numberOfVariablesOutsideBlock = currentlyUsedVariableNames.Count;
base.VisitBlockStatement(blockStatement, data);
foreach (ExpressionStatement stmt in blockStatement.Statements.OfType <ExpressionStatement>().ToArray())
{
Match displayClassAssignmentMatch = displayClassAssignmentPattern.Match(stmt);
if (!displayClassAssignmentMatch.Success)
{
continue;
}
ILVariable variable = displayClassAssignmentMatch.Get <AstNode>("variable").Single().Annotation <ILVariable>();
if (variable == null)
{
continue;
}
TypeDef type = variable.Type.ToTypeDefOrRef().ResolveWithinSameModule();
if (!IsPotentialClosure(context, type))
{
continue;
}
if (displayClassAssignmentMatch.Get <AstType>("type").Single().Annotation <ITypeDefOrRef>().ResolveWithinSameModule() != type)
{
continue;
}
// Looks like we found a display class creation. Now let's verify that the variable is used only for field accesses:
bool ok = true;
foreach (var identExpr in blockStatement.Descendants.OfType <IdentifierExpression>())
{
if (identExpr.Identifier == variable.Name && identExpr != displayClassAssignmentMatch.Get("variable").Single())
{
if (!(identExpr.Parent is MemberReferenceExpression && identExpr.Parent.Annotation <IField>() != null && identExpr.Parent.Annotation <IField>().IsField))
{
ok = false;
}
}
}
if (!ok)
{
continue;
}
Dictionary <IField, AstNode> dict = new Dictionary <IField, AstNode>();
// Delete the variable declaration statement:
VariableDeclarationStatement displayClassVarDecl = PatternStatementTransform.FindVariableDeclaration(stmt, variable.Name);
if (displayClassVarDecl != null)
{
displayClassVarDecl.Remove(); //TODO: Save ILRanges
}
// Delete the assignment statement:
AstNode cur = stmt.NextSibling;
stmt.Remove(); //TODO: Save ILRanges
// Delete any following statements as long as they assign parameters to the display class
BlockStatement rootBlock = blockStatement.Ancestors.OfType <BlockStatement>().LastOrDefault() ?? blockStatement;
List <ILVariable> parameterOccurrances = rootBlock.Descendants.OfType <IdentifierExpression>()
.Select(n => n.Annotation <ILVariable>()).Where(p => p != null && p.IsParameter).ToList();
AstNode next;
for (; cur != null; cur = next)
{
next = cur.NextSibling;
// Test for the pattern:
// "variableName.MemberName = right;"
ExpressionStatement closureFieldAssignmentPattern = new ExpressionStatement(
new AssignmentExpression(
new NamedNode("left", new MemberReferenceExpression {
Target = IdentifierExpression.Create(variable.Name, variable.IsParameter ? TextTokenType.Parameter : TextTokenType.Local),
MemberName = Pattern.AnyString
}),
new AnyNode("right")
)
);
Match m = closureFieldAssignmentPattern.Match(cur);
if (m.Success)
{
FieldDef fieldDef = m.Get <MemberReferenceExpression>("left").Single().Annotation <IField>().ResolveFieldWithinSameModule();
AstNode right = m.Get <AstNode>("right").Single();
bool isParameter = false;
bool isDisplayClassParentPointerAssignment = false;
if (right is ThisReferenceExpression)
{
isParameter = true;
}
else if (right is IdentifierExpression)
{
// handle parameters only if the whole method contains no other occurrence except for 'right'
ILVariable v = right.Annotation <ILVariable>();
isParameter = v.IsParameter && parameterOccurrances.Count(c => c == v) == 1;
if (!isParameter && IsPotentialClosure(context, v.Type.ToTypeDefOrRef().ResolveWithinSameModule()))
{
// parent display class within the same method
// (closure2.localsX = closure1;)
isDisplayClassParentPointerAssignment = true;
}
}
else if (right is MemberReferenceExpression)
{
// copy of parent display class reference from an outer lambda
// closure2.localsX = this.localsY
MemberReferenceExpression mre = m.Get <MemberReferenceExpression>("right").Single();
do
{
// descend into the targets of the mre as long as the field types are closures
FieldDef fieldDef2 = mre.Annotation <FieldDef>().ResolveFieldWithinSameModule();
if (fieldDef2 == null || !IsPotentialClosure(context, fieldDef2.FieldType.ToTypeDefOrRef().ResolveWithinSameModule()))
{
break;
}
// if we finally get to a this reference, it's copying a display class parent pointer
if (mre.Target is ThisReferenceExpression)
{
isDisplayClassParentPointerAssignment = true;
}
mre = mre.Target as MemberReferenceExpression;
} while (mre != null);
}
if (isParameter || isDisplayClassParentPointerAssignment)
{
if (fieldDef != null)
{
dict[fieldDef] = right;
}
cur.Remove(); //TODO: Save ILRanges
}
else
{
break;
}
}
else
{
break;
}
}
// Now create variables for all fields of the display class (except for those that we already handled as parameters)
List <Tuple <AstType, ILVariable> > variablesToDeclare = new List <Tuple <AstType, ILVariable> >();
foreach (FieldDef field in type.Fields)
{
if (field.IsStatic)
{
continue; // skip static fields
}
if (dict.ContainsKey(field)) // skip field if it already was handled as parameter
{
continue;
}
string capturedVariableName = field.Name;
if (capturedVariableName.StartsWith("$VB$Local_", StringComparison.Ordinal) && capturedVariableName.Length > 10)
{
capturedVariableName = capturedVariableName.Substring(10);
}
EnsureVariableNameIsAvailable(blockStatement, capturedVariableName);
currentlyUsedVariableNames.Add(capturedVariableName);
ILVariable ilVar = new ILVariable
{
IsGenerated = true,
Name = capturedVariableName,
Type = field.FieldType,
};
variablesToDeclare.Add(Tuple.Create(AstBuilder.ConvertType(field.FieldType, field), ilVar));
dict[field] = IdentifierExpression.Create(capturedVariableName, TextTokenType.Local).WithAnnotation(ilVar);
}
// Now figure out where the closure was accessed and use the simpler replacement expression there:
foreach (var identExpr in blockStatement.Descendants.OfType <IdentifierExpression>())
{
if (identExpr.Identifier == variable.Name)
{
MemberReferenceExpression mre = (MemberReferenceExpression)identExpr.Parent;
AstNode replacement;
var fieldDef = mre.Annotation <IField>().ResolveFieldWithinSameModule();
if (fieldDef != null && dict.TryGetValue(fieldDef, out replacement))
{
var newReplacement = replacement.Clone();
newReplacement.AddAnnotation(mre.GetAllRecursiveILRanges());
mre.ReplaceWith(newReplacement);
}
}
}
// Now insert the variable declarations (we can do this after the replacements only so that the scope detection works):
Statement insertionPoint = blockStatement.Statements.FirstOrDefault();
foreach (var tuple in variablesToDeclare)
{
var newVarDecl = new VariableDeclarationStatement(tuple.Item2.IsParameter ? TextTokenType.Parameter : TextTokenType.Local, tuple.Item1, tuple.Item2.Name);
newVarDecl.Variables.Single().AddAnnotation(new CapturedVariableAnnotation());
newVarDecl.Variables.Single().AddAnnotation(tuple.Item2);
blockStatement.Statements.InsertBefore(insertionPoint, newVarDecl);
}
}
currentlyUsedVariableNames.RemoveRange(numberOfVariablesOutsideBlock, currentlyUsedVariableNames.Count - numberOfVariablesOutsideBlock);
return(null);
}
