Added an off by default option for generating abstract implementations because the MS ABI branch does not always work.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>

src/Generator/Driver.cs

@@ -148,7 +148,8 @@ namespace CppSharp
             TranslationUnitPasses.AddPass(new CheckIgnoredDeclsPass());
             TranslationUnitPasses.AddPass(new CheckFlagEnumsPass());
             TranslationUnitPasses.AddPass(new CheckDuplicatedNamesPass());
-            TranslationUnitPasses.AddPass(new GenerateAbstractImplementationsPass());
+            if (Options.GenerateAbstractImpls)
+                TranslationUnitPasses.AddPass(new GenerateAbstractImplementationsPass());
         }
 
         public void ProcessCode()
@@ -262,6 +263,7 @@ namespace CppSharp
         public bool GenerateFunctionTemplates;
         public bool GeneratePartialClasses;
         public bool GenerateVirtualTables;
+        public bool GenerateAbstractImpls;
         public bool GenerateInternalImports;
         public string IncludePrefix;
         public bool WriteOnlyWhenChanged;

src/Generator/Generators/CSharp/CSharpMarshal.cs

@@ -216,7 +216,8 @@ namespace CppSharp.Generators.CSharp
                 instance = copy;
             }
 
-            if (@class.IsRefType && !@class.IsAbstract)
+            if (@class.IsRefType &&
+                (!Context.Driver.Options.GenerateAbstractImpls || !@class.IsAbstract))
             {
                 var instanceName = Generator.GeneratedIdentifier("instance");
                 if (VarSuffix > 0)
@@ -253,7 +254,9 @@ namespace CppSharp.Generators.CSharp
             }
 
             Context.Return.Write("new {0}({1})",
-                QualifiedIdentifier(@class) + (@class.IsAbstract ? "Internal" : ""),
+                QualifiedIdentifier(@class) +
+                (Context.Driver.Options.GenerateAbstractImpls && @class.IsAbstract ?
+                    "Internal" : ""),
                 instance);
 
             return true;

src/Generator/Generators/CSharp/CSharpTextTemplate.cs

@@ -626,7 +626,8 @@ namespace CppSharp.Generators.CSharp
             Write(Helpers.GetAccess(@class));
             Write("unsafe ");
 
-            if (@class.IsAbstract)
+            if (Driver.Options.GenerateAbstractImpls &&
+                @class.IsAbstract)
                 Write("abstract ");
 
             if (Options.GeneratePartialClasses)
@@ -1483,9 +1484,11 @@ namespace CppSharp.Generators.CSharp
             PushBlock(CSharpBlockKind.Method);
             GenerateDeclarationCommon(method);
 
-            Write(@class.IsAbstract && method.IsConstructor ? "protected " : "public ");
+            Write(Driver.Options.GenerateAbstractImpls &&
+                @class.IsAbstract && method.IsConstructor ? "protected " : "public ");
 
-            if (method.IsVirtual && !method.IsOverride && !method.IsPure)
+            if (method.IsVirtual && !method.IsOverride &&
+                (!Driver.Options.GenerateAbstractImpls || !method.IsPure))
                 Write("virtual ");
 
             var isBuiltinOperator = method.IsOperator &&
@@ -1497,7 +1500,7 @@ namespace CppSharp.Generators.CSharp
             if (method.IsOverride)
                 Write("override ");
 
-            if (method.IsPure)
+            if (Driver.Options.GenerateAbstractImpls && method.IsPure)
                 Write("abstract ");
 
             var functionName = GetFunctionIdentifier(method);
@@ -1511,7 +1514,7 @@ namespace CppSharp.Generators.CSharp
 
             Write(")");
 
-            if (method.IsPure)
+            if (Driver.Options.GenerateAbstractImpls && method.IsPure)
             {
                 Write(";");
                 PopBlock(NewLineKind.BeforeNextBlock);