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)
@@ -309,14 +309,11 @@ namespace CppSharp.Generators.CSharp
 
             PushBlock(BlockKind.Class);
             GenerateDeclarationCommon(@class);            
-
             GenerateClassSpecifier(@class);
 
             NewLine();
             WriteStartBraceIndent();
             
-            if (!@class.IsOpaque)
-            {
             if (!@class.IsAbstractImpl)
                 GenerateClassInternals(@class);
 
@@ -364,7 +361,6 @@ namespace CppSharp.Generators.CSharp
 
             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);