Incomplete classes and structs are now generated for C#. (#797)

This feature is NOT coming for C++/CLI !

src/AST/Class.cs

@@ -96,8 +96,20 @@ namespace CppSharp.AST
         // True if the class is final / sealed.
         public bool IsFinal { get; set; }
 
+        private bool? isOpaque = null;
+
         // True if the type is to be treated as opaque.
-        public bool IsOpaque;
+        public bool IsOpaque
+        {
+            get
+            {
+                return isOpaque == null ? IsIncomplete && CompleteDeclaration == null : isOpaque.Value;
+            }
+            set
+            {
+                isOpaque = value;
+            }
+        }
 
         // True if the class is dynamic.
         public bool IsDynamic;
@@ -127,7 +139,6 @@ namespace CppSharp.AST
             IsAbstract = false;
             IsUnion = false;
             IsFinal = false;
-            IsOpaque = false;
             IsPOD = false;
             Type = ClassType.RefType;
             Layout = new ClassLayout();

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -272,7 +272,7 @@ namespace CppSharp.Generators.CSharp
 
         public override bool VisitClassDecl(Class @class)
         {
-            if (@class.IsIncomplete)
+            if (@class.IsIncomplete && !@class.IsOpaque)
                 return false;
 
             if (@class.IsInterface)
@@ -308,63 +308,59 @@ namespace CppSharp.Generators.CSharp
             }
 
             PushBlock(BlockKind.Class);
-            GenerateDeclarationCommon(@class);
-
+            GenerateDeclarationCommon(@class);            
             GenerateClassSpecifier(@class);
 
             NewLine();
             WriteStartBraceIndent();
+            
+            if (!@class.IsAbstractImpl)
+                GenerateClassInternals(@class);
 
-            if (!@class.IsOpaque)
-            {
-                if (!@class.IsAbstractImpl)
-                    GenerateClassInternals(@class);
-
-                VisitDeclContext(@class);
+            VisitDeclContext(@class);
 
-                if (@class.IsDependent || !@class.IsGenerated)
-                    goto exit;
+            if (@class.IsDependent || !@class.IsGenerated)
+                goto exit;
 
-                if (ShouldGenerateClassNativeField(@class))
+            if (ShouldGenerateClassNativeField(@class))
+            {
+                PushBlock(BlockKind.Field);
+                if (@class.IsValueType)
                 {
-                    PushBlock(BlockKind.Field);
-                    if (@class.IsValueType)
-                    {
-                        WriteLine("private {0}.{1} {2};", @class.Name, Helpers.InternalStruct,
-                            Helpers.InstanceField);
-                        WriteLine("internal {0}.{1} {2} {{ get {{ return {3}; }} }}", @class.Name,
-                            Helpers.InternalStruct, Helpers.InstanceIdentifier, Helpers.InstanceField);
-                    }
-                    else
-                    {
-                        WriteLine("public {0} {1} {{ get; protected set; }}",
-                            CSharpTypePrinter.IntPtrType, Helpers.InstanceIdentifier);
+                    WriteLine("private {0}.{1} {2};", @class.Name, Helpers.InternalStruct,
+                        Helpers.InstanceField);
+                    WriteLine("internal {0}.{1} {2} {{ get {{ return {3}; }} }}", @class.Name,
+                        Helpers.InternalStruct, Helpers.InstanceIdentifier, Helpers.InstanceField);
+                }
+                else
+                {
+                    WriteLine("public {0} {1} {{ get; protected set; }}",
+                        CSharpTypePrinter.IntPtrType, Helpers.InstanceIdentifier);
 
-                        PopBlock(NewLineKind.BeforeNextBlock);
+                    PopBlock(NewLineKind.BeforeNextBlock);
 
-                        PushBlock(BlockKind.Field);
+                    PushBlock(BlockKind.Field);
 
-                        WriteLine("protected int {0};", Helpers.PointerAdjustmentIdentifier);
+                    WriteLine("protected int {0};", Helpers.PointerAdjustmentIdentifier);
 
-                        // use interfaces if any - derived types with a secondary base this class must be compatible with the map
-                        var @interface = @class.Namespace.Classes.Find(c => c.OriginalClass == @class);
-                        var dict = string.Format("global::System.Collections.Concurrent.ConcurrentDictionary<IntPtr, {0}>",
-                            (@interface ?? @class).Visit(TypePrinter));
-                        WriteLine("internal static readonly {0} NativeToManagedMap = new {0}();", dict);
-                        WriteLine("protected void*[] __OriginalVTables;");
-                    }
-                    PopBlock(NewLineKind.BeforeNextBlock);
+                    // use interfaces if any - derived types with a secondary base this class must be compatible with the map
+                    var @interface = @class.Namespace.Classes.Find(c => c.OriginalClass == @class);
+                    var dict = string.Format("global::System.Collections.Concurrent.ConcurrentDictionary<IntPtr, {0}>",
+                        (@interface ?? @class).Visit(TypePrinter));
+                    WriteLine("internal static readonly {0} NativeToManagedMap = new {0}();", dict);
+                    WriteLine("protected void*[] __OriginalVTables;");
                 }
+                PopBlock(NewLineKind.BeforeNextBlock);
+            }
 
-                GenerateClassConstructors(@class);
+            GenerateClassConstructors(@class);
 
-                GenerateClassMethods(@class.Methods);
-                GenerateClassVariables(@class);
-                GenerateClassProperties(@class);
+            GenerateClassMethods(@class.Methods);
+            GenerateClassVariables(@class);
+            GenerateClassProperties(@class);
 
-                if (@class.IsDynamic)
-                    GenerateVTable(@class);
-            }
+            if (@class.IsDynamic)
+                GenerateVTable(@class);
         exit:
             WriteCloseBraceIndent();
             PopBlock(NewLineKind.BeforeNextBlock);

src/Generator/Passes/CheckIgnoredDecls.cs

@@ -369,6 +369,14 @@ namespace CppSharp.Passes
                 return true;
             }
 
+            var @class = decl as Class;
+            if (@class != null && @class.IsOpaque && !@class.IsDependent && 
+                !(@class is ClassTemplateSpecialization))
+            {
+                msg = null;
+                return false;
+            }
+
             if (decl.IsIncomplete)
             {
                 msg = "incomplete";
@@ -400,6 +408,11 @@ namespace CppSharp.Passes
 
             Declaration decl;
             if (!finalType.TryGetDeclaration(out decl)) return true;
+
+            var @class = (decl as Class);
+            if (@class != null && @class.IsOpaque && !@class.IsDependent && 
+                !(@class is ClassTemplateSpecialization))
+                return true;
             return !decl.IsIncomplete || decl.CompleteDeclaration != null;
         }
 

src/Generator/Passes/ResolveIncompleteDeclsPass.cs

@@ -67,6 +67,9 @@ namespace CppSharp.Passes
             if (declaration.CompleteDeclaration != null)
                 return;
 
+            var @class = declaration as Class;
+            if (@class != null && @class.IsOpaque) return;
+
             declaration.CompleteDeclaration =
                 ASTContext.FindCompleteClass(declaration.QualifiedName);
 

src/Parser/ASTConverter.cs

@@ -994,7 +994,7 @@ namespace CppSharp
             {
                 var decl = ctx.GetClasses(i);
                 var _decl = Visit(decl) as AST.Class;
-                if (!_decl.IsIncomplete)
+                if (!_decl.IsIncomplete || _decl.IsOpaque)
                     _ctx.Classes.Add(_decl);
             }
 

tests/CSharp/CSharp.Tests.cs

@@ -698,4 +698,12 @@ public unsafe class CSharpTests : GeneratorTestFixture
             return base.HasPointerToEnumInParam(pointerToEnum);
         }
     }
+
+    [Test]
+    public void TestGenerationOfIncompleteClasses()
+    {
+        var incompleteStruct = CSharp.CSharp.CreateIncompleteStruct();
+        Assert.IsNotNull(incompleteStruct);
+        Assert.DoesNotThrow(() => CSharp.CSharp.UseIncompleteStruct(incompleteStruct));
+    }
 }

tests/CSharp/CSharp.cpp

@@ -1310,3 +1310,15 @@ void HasGetterAndOverriddenSetter::setBaseSetter(int value)
 void hasArrayOfConstChar(const char* const arrayOfConstChar[])
 {
 }
+
+struct IncompleteStruct {};
+
+IncompleteStruct* createIncompleteStruct()
+{
+    return new IncompleteStruct();
+}
+
+DLL_API void useIncompleteStruct(IncompleteStruct * a)
+{
+    return;
+}

tests/CSharp/CSharp.h

@@ -1151,3 +1151,10 @@ protected:
 };
 
 void DLL_API hasArrayOfConstChar(const char* const arrayOfConstChar[]);
+
+struct CompleteIncompleteStruct;
+
+typedef struct IncompleteStruct IncompleteStruct;
+
+DLL_API IncompleteStruct* createIncompleteStruct();
+DLL_API void useIncompleteStruct(IncompleteStruct* a);