Write the "this" parameter type of a method as ref type instead of anyref.

src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java

@@ -467,10 +467,7 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
         localsStream.writeVaruint32( locals.size() );
         for( AnyType valueType : locals ) {
             localsStream.writeVaruint32( 1 ); // TODO optimize, write the count of same types.
-            if( valueType.getCode() >= 0 ) {
+            localsStream.writeRefValueType( valueType );
-                localsStream.writeValueType( ValueType.ref_type );
-            }
-            localsStream.writeValueType( valueType );
         }
         WasmOutputStream functionsStream = function.functionsStream = new WasmOutputStream();
         functionsStream.writeVaruint32( localsStream.size() + codeStream.size() + 1 );

src/de/inetsoftware/jwebassembly/binary/FunctionTypeEntry.java

@@ -48,11 +48,11 @@ class FunctionTypeEntry extends TypeEntry {
     void writeSectionEntryDetails( WasmOutputStream stream ) throws IOException {
         stream.writeVaruint32( this.params.size() );
         for( AnyType valueType : this.params ) {
-            stream.writeValueType( valueType );
+            stream.writeRefValueType( valueType );
         }
         stream.writeVaruint32( this.results.size() );
         for( AnyType valueType : this.results ) {
-            stream.writeValueType( valueType );
+            stream.writeRefValueType( valueType );
         }
     }
 

src/de/inetsoftware/jwebassembly/binary/StructTypeEntry.java

@@ -56,10 +56,7 @@ class StructTypeEntry extends TypeEntry {
         stream.writeVaruint32( this.fields.size() );
         for( NamedStorageType field : this.fields ) {
             stream.writeVarint( 1 ); // 0 - immutable; 1 - mutable 
-            if( field.getType().getCode() > 0  ) {
+            stream.writeRefValueType( field.getType() );
-                stream.writeValueType( ValueType.ref_type );
-            }
-            stream.writeValueType( field.getType() );
         }
     }
 

src/de/inetsoftware/jwebassembly/binary/WasmOutputStream.java

@@ -96,6 +96,21 @@ class WasmOutputStream extends FilterOutputStream {
         writeVarint( type.getCode() );
     }
 
+    /**
+     * Write the value type. If it is a struct type then as reference type.
+     * 
+     * @param type
+     *            a type constant
+     * @throws IOException
+     *             if an I/O error occurs.
+     */
+    public void writeRefValueType( AnyType type ) throws IOException {
+        if( type.getCode() >= 0 ) {
+            writeValueType( ValueType.ref_type );
+        }
+        writeValueType( type );
+    }
+
     /**
      * Write a integer little endian (ever 4 bytes)
      * 

src/de/inetsoftware/jwebassembly/module/ModuleGenerator.java

@@ -210,9 +210,7 @@ public class ModuleGenerator {
      */
     private void setStructType( WasmStructInstruction instruction ) throws IOException {
         StructType type = instruction.getStructType();
-        if( type != null && type.getCode() == Integer.MAX_VALUE ) {
+        writeStructType( type );
-            writeStructType( type );
-        }
     }
 
     /**
@@ -224,6 +222,9 @@ public class ModuleGenerator {
      *             if any I/O error occur
      */
     private void writeStructType( StructType type ) throws IOException {
+        if( type == null || type.getCode() != Integer.MAX_VALUE ) {
+            return;
+        }
         String className = type.getName();
         List<NamedStorageType> list = new ArrayList<>();
         listStructFields( className, list );
@@ -231,14 +232,15 @@ public class ModuleGenerator {
         int id = writer.writeStruct( className, list );
         types.useType( type, id, list );
         for( NamedStorageType namedType : list ) {
-            if( namedType.getType().getCode() == Integer.MAX_VALUE ) {
+            AnyType fieldType = namedType.getType();
-                writeStructType( (StructType)namedType.getType() );
+            if( fieldType.getCode() == Integer.MAX_VALUE ) {
+                writeStructType( (StructType)fieldType );
             }
         }
     }
 
     /**
-     * List the non static fields of the class and its superclasses.
+     * List the non static fields of the class and its super classes.
      * 
      * @param className
      *            the className
@@ -488,7 +490,9 @@ public class ModuleGenerator {
     private void writeMethodSignature( FunctionName name, boolean isStatic, WasmCodeBuilder codeBuilder ) throws IOException, WasmException {
         int paramCount = 0;
         if( !isStatic ) {
-            writer.writeMethodParam( "param", ValueType.anyref, "this" );
+            StructType instanceType = types.valueOf( name.className );
+            writeStructType( instanceType );
+            writer.writeMethodParam( "param", instanceType, "this" );
         }
         Iterator<AnyType> parser = name.getSignature();
         AnyType type;