Use UnsupportedType description for type name instead of empty string (#1339)

Use UnsupportedType description for type name instead of empty string

src/Generator/Generators/C/CppTypePrinter.cs

@@ -363,7 +363,7 @@ namespace CppSharp.Generators.C
         public override TypePrinterResult VisitUnsupportedType(UnsupportedType type,
             TypeQualifiers quals)
         {
-            return string.Empty;
+            return type.Description;
         }
 
         public override TypePrinterResult VisitDeclaration(Declaration decl,

tests/CLI/CLI.Tests.cs

@@ -44,4 +44,16 @@ public class CLITests : GeneratorTestFixture
             Assert.AreEqual(ClassWithNestedEnum.NestedEnum.E1, consumer.GetPassedEnum(ClassWithNestedEnum.NestedEnum.E1));
         }
     }
+
+    [Test]
+    public void TestChangePassedMappedTypeNonConstRefParam()
+    {
+        using (TestMappedTypeNonConstRefParamConsumer consumer = new TestMappedTypeNonConstRefParamConsumer())
+        {
+            string val = "Initial";
+            consumer.ChangePassedMappedTypeNonConstRefParam(ref val);
+
+            Assert.AreEqual("ChangePassedMappedTypeNonConstRefParam", val);
+        }
+    }
 }

tests/CLI/CLI.cpp

@@ -31,3 +31,20 @@ EnumParam TestByRefEnumParam::GetPassedEnumParam(EnumParam & e)
 {
     return e;
 }
+
+TestMappedTypeNonConstRefParam::TestMappedTypeNonConstRefParam(const std::string str)
+{
+    m_str = str;
+}
+
+const TestMappedTypeNonConstRefParam & TestMappedTypeNonConstRefParam::operator=(const std::string str)
+{
+    m_str = str;
+
+    return *this;
+}
+
+void TestMappedTypeNonConstRefParamConsumer::ChangePassedMappedTypeNonConstRefParam(TestMappedTypeNonConstRefParam & v)
+{
+    v = "ChangePassedMappedTypeNonConstRefParam";
+}

tests/CLI/CLI.cs

@@ -1,5 +1,7 @@
 using CppSharp.AST;
 using CppSharp.Generators;
+using CppSharp.Generators.C;
+using CppSharp.Passes;
 using CppSharp.Types;
 using CppSharp.Utils;
 
@@ -19,6 +21,42 @@ namespace CppSharp.Tests
         }
     }
 
+    [TypeMap("TestMappedTypeNonConstRefParam")]
+    public class TestMappedTypeNonConstRefParamTypeMap : TypeMap
+    {
+        public override Type CLISignatureType(TypePrinterContext ctx)
+        {
+            return new CILType(typeof(string));
+        }
+
+        public override Type CppSignatureType(TypePrinterContext ctx)
+        {
+            var tagType = ctx.Type as TagType;
+            var typePrinter = new CppTypePrinter(Context);
+            return new CustomType(tagType.Declaration.Visit(typePrinter));
+        }
+
+        public override void CLIMarshalToManaged(MarshalContext ctx)
+        {
+            ctx.Return.Write("clix::marshalString<clix::E_UTF8>({0}.m_str)", ctx.ReturnVarName);
+        }
+
+        public override void CLIMarshalToNative(MarshalContext ctx)
+        {
+            if (ctx.Parameter.Usage == ParameterUsage.InOut)
+            {
+                ctx.Before.WriteLine($"System::String^ _{ctx.Parameter.Name} = {ctx.Parameter.Name};");
+            }
+
+            string paramName = ctx.Parameter.Usage == ParameterUsage.InOut ? $"_{ctx.Parameter.Name}" : ctx.Parameter.Name;
+
+            ctx.Before.WriteLine(
+                $"::TestMappedTypeNonConstRefParam _{ctx.ArgName} = clix::marshalString<clix::E_UTF8>({paramName});");
+
+            ctx.Return.Write("_{0}", ctx.ArgName);
+        }
+    }
+
     public class CLITestsGenerator : GeneratorTest
     {
         public CLITestsGenerator(GeneratorKind kind)
@@ -33,6 +71,12 @@ namespace CppSharp.Tests
             base.Setup(driver);
         }
 
+        public override void Preprocess(Driver driver, ASTContext ctx)
+        {
+            LibraryHelpers.SetMethodParameterUsage(ctx, "TestMappedTypeNonConstRefParamConsumer",
+                "ChangePassedMappedTypeNonConstRefParam", 1, ParameterUsage.InOut);
+        }
+
         public static void Main(string[] args)
         {
             ConsoleDriver.Run(new CLITestsGenerator(GeneratorKind.CLI));

tests/CLI/CLI.h

@@ -73,4 +73,19 @@ class DLL_API TestByRefEnumParam
 {
 public:
     EnumParam GetPassedEnumParam(EnumParam& e);
+};
+
+class DLL_API TestMappedTypeNonConstRefParam
+{
+public:
+    TestMappedTypeNonConstRefParam(const std::string);
+    const TestMappedTypeNonConstRefParam& operator=(const std::string);
+
+    std::string m_str;
+};
+
+class DLL_API TestMappedTypeNonConstRefParamConsumer
+{
+public:
+    void ChangePassedMappedTypeNonConstRefParam(TestMappedTypeNonConstRefParam&);
 };