Add C# solution-based parsing and cross-language namespace mappings

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: macsux

rewrite-csharp/build.gradle.kts

@@ -89,6 +89,7 @@ tasks.withType<Test> {
     dependsOn(csharpBuild)
 
     maxParallelForks = 1
+    maxHeapSize = "4g"
     // Add timeout to identify hanging tests
     systemProperty("junit.jupiter.execution.timeout.default", "30s")
     // Show test names as they run

rewrite-csharp/csharp/OpenRewrite/CSharp/CSharpParser.cs

@@ -2311,6 +2311,44 @@ public override J VisitUnary(Unary unary, PrintOutputCapture<P> p)
         return unary;
     }
 
+    public override J VisitCsUnary(CsUnary csUnary, PrintOutputCapture<P> p)
+    {
+        BeforeSyntax(csUnary, p);
+
+        var op = csUnary.Operator.Element;
+        bool isPostfix = op == CsUnary.OperatorKind.SuppressNullableWarning;
+
+        if (!isPostfix)
+        {
+            p.Append(GetCsUnaryOperatorString(op));
+        }
+
+        Visit(csUnary.Expression, p);
+
+        if (isPostfix)
+        {
+            VisitSpace(csUnary.Operator.Before, p);
+            p.Append(GetCsUnaryOperatorString(op));
+        }
+
+        AfterSyntax(csUnary, p);
+        return csUnary;
+    }
+
+    private static string GetCsUnaryOperatorString(CsUnary.OperatorKind op)
+    {
+        return op switch
+        {
+            CsUnary.OperatorKind.SuppressNullableWarning => "!",
+            CsUnary.OperatorKind.PointerIndirection => "*",
+            CsUnary.OperatorKind.PointerType => "*",
+            CsUnary.OperatorKind.AddressOf => "&",
+            CsUnary.OperatorKind.Spread => "..",
+            CsUnary.OperatorKind.FromEnd => "^",
+            _ => throw new InvalidOperationException($"Unknown CsUnary operator: {op}")
+        };
+    }
+
     private static string GetUnaryOperatorString(Unary.OperatorType op)
     {
         return op switch

rewrite-csharp/csharp/OpenRewrite/CSharp/CSharpPrinter.cs

@@ -118,9 +118,20 @@ private JavaType MapNamedType(INamedTypeSymbol symbol)
             _typeCache[symbol] = parameterized;
 
             var rawType = MapNamedType(symbol.OriginalDefinition);
-            var typeArgs = symbol.TypeArguments.Select(MapType).ToList()!;
-            parameterized.UnsafeSet(rawType as JavaType.FullyQualified, typeArgs!);
-            return parameterized;
+
+            // Guard: if rawType resolved back to the same Parameterized (cache collision
+            // between symbol and OriginalDefinition) or is not a FullyQualified, fall back
+            if (ReferenceEquals(rawType, parameterized) || rawType is not JavaType.FullyQualified fq)
+            {
+                _typeCache.Remove(symbol);
+                // Fall through to create as a plain Class below
+            }
+            else
+            {
+                var typeArgs = symbol.TypeArguments.Select(MapType).ToList()!;
+                parameterized.UnsafeSet(fq, typeArgs!);
+                return parameterized;
+            }
         }
 
         // Shell cache pattern: create empty shell, cache it, then populate

rewrite-csharp/csharp/OpenRewrite/CSharp/CSharpTypeMapping.cs

@@ -56,7 +56,6 @@ public class CSharpVisitor<P> : JavaVisitor<P>
             NullSafeExpression nse => VisitNullSafeExpression(nse, p),
             // New types
             Keyword kw => VisitKeyword(kw, p),
-            CsArgument csa => VisitCsArgument(csa, p),
             NameColon nc => VisitNameColon(nc, p),
             AnnotatedStatement ans => VisitAnnotatedStatement(ans, p),
             ArrayRankSpecifier ars => VisitArrayRankSpecifier(ars, p),
@@ -602,12 +601,6 @@ public virtual J VisitLineDirective(LineDirective lineDirective, P p)
 
     public virtual J VisitKeyword(Keyword keyword, P p) => keyword;
 
-    public virtual J VisitCsArgument(CsArgument csArgument, P p)
-    {
-        Visit(csArgument.Expression, p);
-        return csArgument;
-    }
-
     public virtual J VisitNameColon(NameColon nameColon, P p) => nameColon;
 
     public virtual J VisitAnnotatedStatement(AnnotatedStatement annotatedStatement, P p)

rewrite-csharp/csharp/OpenRewrite/CSharp/CSharpVisitor.cs

@@ -704,7 +704,7 @@ public sealed class StatementExpression(
     Space prefix,
     Markers markers,
     Statement statement
-) : Cs, Expression, IEquatable<StatementExpression>
+) : Pattern, IEquatable<StatementExpression>
 {
     public Guid Id { get; } = id;
     public Space Prefix { get; } = prefix;
@@ -2812,21 +2812,21 @@ public sealed class ImplicitElementAccess(
     Guid id,
     Space prefix,
     Markers markers,
-    JContainer<CsArgument> argumentList
+    JContainer<Expression> argumentList
 ) : Cs, Expression, IEquatable<ImplicitElementAccess>
 {
     public Guid Id { get; } = id;
     public Space Prefix { get; } = prefix;
     public Markers Markers { get; } = markers;
-    public JContainer<CsArgument> ArgumentList { get; } = argumentList;
+    public JContainer<Expression> ArgumentList { get; } = argumentList;
 
     public ImplicitElementAccess WithId(Guid id) =>
         id == Id ? this : new(id, Prefix, Markers, ArgumentList);
     public ImplicitElementAccess WithPrefix(Space prefix) =>
         ReferenceEquals(prefix, Prefix) ? this : new(Id, prefix, Markers, ArgumentList);
     public ImplicitElementAccess WithMarkers(Markers markers) =>
         ReferenceEquals(markers, Markers) ? this : new(Id, Prefix, markers, ArgumentList);
-    public ImplicitElementAccess WithArgumentList(JContainer<CsArgument> argumentList) =>
+    public ImplicitElementAccess WithArgumentList(JContainer<Expression> argumentList) =>
         ReferenceEquals(argumentList, ArgumentList) ? this : new(Id, Prefix, Markers, argumentList);
 
     Tree Tree.WithId(Guid id) => WithId(id);

rewrite-csharp/csharp/OpenRewrite/CSharp/Cs.cs

@@ -89,7 +89,6 @@ public CSharpReceiver()
             NullSafeExpression nse => VisitNullSafeExpression(nse, q),
             // New types
             Keyword kw => VisitKeyword(kw, q),
-            CsArgument csa => VisitCsArgument(csa, q),
             NameColon nc => VisitNameColon(nc, q),
             AnnotatedStatement ans => VisitAnnotatedStatement(ans, q),
             ArrayRankSpecifier ars => VisitArrayRankSpecifier(ars, q),
@@ -198,7 +197,11 @@ public override J VisitCompilationUnit(CompilationUnit cu, RpcReceiveQueue q)
 
         // Reconstruct members
         var allMembers = new List<Statement>();
-        if (usings != null) allMembers.AddRange(usings.Select(rp => rp.Element));
+        if (usings != null)
+        {
+            foreach (var rp in usings)
+                allMembers.Add(rp.Element);
+        }
         if (attrLists != null) allMembers.AddRange(attrLists);
         if (members != null) allMembers.AddRange(members.Select(rp => rp.Element));
 
@@ -208,13 +211,14 @@ public override J VisitCompilationUnit(CompilationUnit cu, RpcReceiveQueue q)
     // ---- UsingDirective ----
     public override J VisitUsingDirective(UsingDirective ud, RpcReceiveQueue q)
     {
-        q.Receive(ud.IsGlobal ? (object?)ud.Global : null);
-        q.Receive(ud.IsStatic ? (object?)ud.Static : null);
-        // Unsafe: nagoya doesn't model this
-        q.Receive<object?>(null);
+        var global = q.Receive(ud.Global, rp => _delegate.VisitRightPadded(rp, q));
+        var @static = q.Receive(ud.Static, lp => _delegate.VisitLeftPadded(lp, q));
+        // Unsafe: nagoya doesn't model this; consume and discard
+        q.Receive(new JLeftPadded<bool>(Space.Empty, false), lp => _delegate.VisitLeftPadded(lp, q));
         var alias = q.Receive(ud.Alias, rp => _delegate.VisitRightPadded(rp!, q));
         var namespaceOrType = q.Receive((J)ud.NamespaceOrType, el => (J)VisitNonNull(el, q));
-        return ud.WithId(PvId).WithPrefix(PvPrefix).WithMarkers(PvMarkers).WithAlias(alias).WithNamespaceOrType((TypeTree)namespaceOrType!);
+        return ud.WithId(PvId).WithPrefix(PvPrefix).WithMarkers(PvMarkers)
+            .WithGlobal(global!).WithStatic(@static!).WithAlias(alias).WithNamespaceOrType((TypeTree)namespaceOrType!);
     }
 
     // ---- PropertyDeclaration ----
@@ -563,14 +567,6 @@ public override J VisitKeyword(Keyword kw, RpcReceiveQueue q)
         return kw.WithId(PvId).WithPrefix(PvPrefix).WithMarkers(PvMarkers).WithKind((KeywordKind)kind!);
     }
 
-    public override J VisitCsArgument(CsArgument arg, RpcReceiveQueue q)
-    {
-        var nameColumn = q.Receive(arg.NameColumn, rp => _delegate.VisitRightPadded(rp!, q));
-        var refKindKeyword = q.Receive((J?)arg.RefKindKeyword, el => (J)VisitNonNull(el!, q));
-        var expression = q.Receive((J)arg.Expression, el => (J)VisitNonNull(el, q));
-        return arg.WithId(PvId).WithPrefix(PvPrefix).WithMarkers(PvMarkers).WithNameColumn(nameColumn).WithRefKindKeyword((Keyword?)refKindKeyword).WithExpression((Expression)expression!);
-    }
-
     public override J VisitNameColon(NameColon nc, RpcReceiveQueue q)
     {
         var name = q.Receive(nc.Name, rp => _delegate.VisitRightPadded(rp, q));

rewrite-csharp/csharp/OpenRewrite/CSharp/Rpc/CSharpReceiver.cs

@@ -94,7 +94,6 @@ public CSharpSender()
             NullSafeExpression nse => VisitNullSafeExpression(nse, q),
             // New types
             Keyword kw => VisitKeyword(kw, q),
-            CsArgument csa => VisitCsArgument(csa, q),
             NameColon nc => VisitNameColon(nc, q),
             AnnotatedStatement ans => VisitAnnotatedStatement(ans, q),
             ArrayRankSpecifier ars => VisitArrayRankSpecifier(ars, q),
@@ -217,12 +216,10 @@ public override J VisitCompilationUnit(CompilationUnit cu, RpcSendQueue q)
     // Nagoya model: Global (RP<bool>), Static (LP<bool>), Alias (RP<Identifier>?), NamespaceOrType
     public override J VisitUsingDirective(UsingDirective ud, RpcSendQueue q)
     {
-        // Send null for Global/Static when absent; nagoya's bool representation doesn't
-        // match Java's Keyword tree, but null/NO_CHANGE is protocol-compatible for absent cases
-        q.GetAndSend(ud, u => u.IsGlobal ? (object?)u.Global : null);
-        q.GetAndSend(ud, u => u.IsStatic ? (object?)u.Static : null);
-        // Unsafe: nagoya doesn't model this
-        q.GetAndSend(ud, _ => (object?)null);
+        q.GetAndSend(ud, u => u.Global, rp => VisitRightPadded(rp, q));
+        q.GetAndSend(ud, u => u.Static, lp => VisitLeftPadded(lp, q));
+        // Unsafe: nagoya doesn't model this, send a default JLeftPadded<bool>(false)
+        q.GetAndSend(ud, _ => new JLeftPadded<bool>(Space.Empty, false), lp => VisitLeftPadded(lp, q));
         q.GetAndSend(ud, u => u.Alias, rp => VisitRightPadded(rp!, q));
         q.GetAndSend(ud, u => (J)u.NamespaceOrType, el => Visit(el, q));
         return ud;
@@ -672,14 +669,6 @@ public override J VisitKeyword(Keyword kw, RpcSendQueue q)
         return kw;
     }
 
-    public override J VisitCsArgument(CsArgument arg, RpcSendQueue q)
-    {
-        q.GetAndSend(arg, a => a.NameColumn, rp => VisitRightPadded(rp!, q));
-        q.GetAndSend(arg, a => (J?)a.RefKindKeyword, el => Visit(el!, q));
-        q.GetAndSend(arg, a => (J)a.Expression, el => Visit(el, q));
-        return arg;
-    }
-
     public override J VisitNameColon(NameColon nc, RpcSendQueue q)
     {
         q.GetAndSend(nc, n => n.Name, rp => VisitRightPadded(rp, q));