Added C# marshalling of parameters of type array of const char* const.

Fixes https://github.com/mono/CppSharp/issues/692.

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

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -1032,11 +1032,12 @@ namespace CppSharp.Generators.CSharp
 
             Type varType = var.Type.Desugar();
             var arrayType = varType as ArrayType;
+            var elementType = arrayType?.Type.Desugar();
             var @class = var.Namespace as Class;
             var isRefTypeArray = arrayType != null && @class != null && @class.IsRefType;
             if (isRefTypeArray)
             {
-                string cast = arrayType.Type.IsPrimitiveType(PrimitiveType.Char) &&
+                string cast = elementType.IsPrimitiveType(PrimitiveType.Char) &&
                     arrayType.QualifiedType.Qualifiers.IsConst
                         ? string.Empty : "(byte*)";
                 WriteLine($"var {ptr} = {cast}{location};");
@@ -1054,11 +1055,18 @@ namespace CppSharp.Generators.CSharp
             var ctx = new CSharpMarshalContext(Context)
             {
                 ArgName = var.Name,
-                ReturnVarName = (isRefTypeArray ||
-                    (arrayType != null && arrayType.Type.Desugar().IsPrimitiveType()) ? string.Empty : "*")
-                    + Generator.GeneratedIdentifier("ptr"),
                 ReturnType = new QualifiedType(var.Type)
             };
+            var prefix = string.Empty;
+            if (!isRefTypeArray && elementType == null)
+                ctx.ReturnVarName = $"*{ptr}";
+            else if (elementType == null || elementType.IsPrimitiveType() ||
+                arrayType.SizeType == ArrayType.ArraySize.Constant)
+                ctx.ReturnVarName = ptr;
+            else
+                ctx.ReturnVarName = $@"{elementType}.{
+                    Helpers.CreateInstanceIdentifier}(new {
+                        CSharpTypePrinter.IntPtrType}({ptr}))";
 
             var marshal = new CSharpMarshalNativeToManagedPrinter(ctx);
             var.QualifiedType.Visit(marshal);

src/Generator/Generators/CSharp/CSharpTypePrinter.cs

@@ -134,7 +134,8 @@ namespace CppSharp.Generators.CSharp
 
             var arraySuffix = array.SizeType != ArrayType.ArraySize.Constant &&
                 MarshalKind == MarshalKind.ReturnVariableArray ?
-                (ContextKind == TypePrinterContextKind.Managed ? "*" : string.Empty) : "[]";
+                (ContextKind == TypePrinterContextKind.Managed &&
+                 arrayType.IsPrimitiveType() ? "*" : string.Empty) : "[]";
             return $"{arrayType.Visit(this)}{arraySuffix}";
         }
 

src/Generator/Types/TypeIgnoreChecker.cs

@@ -138,22 +138,14 @@ namespace CppSharp
                 return false;
             }
 
-            var arrayElemType = array.Type.Desugar();
-
-            if (array.SizeType == ArrayType.ArraySize.Incomplete &&
-                array.QualifiedType.Qualifiers.IsConst &&
-                !arrayElemType.IsPrimitiveType())
-            {
-                Ignore();
-                return false;
-            }
-
             if (!array.QualifiedType.Visit(this))
                 return false;
 
             if (array.SizeType != ArrayType.ArraySize.Constant)
                 return true;
 
+            var arrayElemType = array.Type.Desugar();
+
             Class @class;
             if (arrayElemType.TryGetClass(out @class) && @class.IsRefType)
                 return true;

tests/CSharp/CSharp.Tests.cs

@@ -1074,6 +1074,7 @@ public unsafe class CSharpTests : GeneratorTestFixture
     {
         string[] strings = { "The ", "test ", "works." };
         Assert.That(CSharp.CSharp.TakeStringArray(strings), Is.EqualTo("The test works."));
+        Assert.That(CSharp.CSharp.TakeConstStringArray(strings), Is.EqualTo("The test works."));
     }
 
     private class OverrideVirtualTemplate : VirtualTemplate<int>

tests/CSharp/CSharp.cpp

@@ -1408,3 +1408,8 @@ std::string takeStringArray(const char* arrayOfStrings[])
     }
     return result;
 }
+
+std::string takeConstStringArray(const char* const arrayOfStrings[])
+{
+    return takeStringArray(const_cast<const char**>(arrayOfStrings));
+}

tests/CSharp/CSharp.h

@@ -1240,3 +1240,5 @@ inline namespace InlineNamespace
 DLL_API int takeArrays(Foo* arrayOfPointersToObjects[], int arrayOfPrimitives[], Foo arrayOfObjects[]);
 
 DLL_API std::string takeStringArray(const char* arrayOfStrings[]);
+
+DLL_API std::string takeConstStringArray(const char* const arrayOfStrings[]);