use a synthetic function call to calculate the function id of a virtual call.

src/de/inetsoftware/jwebassembly/JWebAssembly.java

@@ -40,9 +40,9 @@ import de.inetsoftware.classparser.ClassFile;
 import de.inetsoftware.jwebassembly.binary.BinaryModuleWriter;
 import de.inetsoftware.jwebassembly.module.ModuleGenerator;
 import de.inetsoftware.jwebassembly.module.ModuleWriter;
+import de.inetsoftware.jwebassembly.module.WasmOptions;
 import de.inetsoftware.jwebassembly.module.WasmTarget;
 import de.inetsoftware.jwebassembly.text.TextModuleWriter;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 
 /**
  * The main class of the compiler.

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

@@ -32,6 +32,7 @@ import de.inetsoftware.jwebassembly.module.FunctionName;
 import de.inetsoftware.jwebassembly.module.ModuleWriter;
 import de.inetsoftware.jwebassembly.module.TypeManager.StructType;
 import de.inetsoftware.jwebassembly.module.ValueTypeConvertion;
+import de.inetsoftware.jwebassembly.module.WasmOptions;
 import de.inetsoftware.jwebassembly.module.WasmTarget;
 import de.inetsoftware.jwebassembly.sourcemap.SourceMapWriter;
 import de.inetsoftware.jwebassembly.sourcemap.SourceMapping;
@@ -44,7 +45,6 @@ import de.inetsoftware.jwebassembly.wasm.StructOperator;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
 import de.inetsoftware.jwebassembly.wasm.VariableOperator;
 import de.inetsoftware.jwebassembly.wasm.WasmBlockOperator;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 
 /**
  * Module Writer for binary format. http://webassembly.org/docs/binary-encoding/

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

@@ -25,7 +25,7 @@ import de.inetsoftware.jwebassembly.wasm.VariableOperator;
  * 
  * @author Volker Berlin
  */
-public class CodeOptimizer {
+class CodeOptimizer {
 
     /**
      * Optimize the code before writing.

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

@@ -34,7 +34,7 @@ import de.inetsoftware.jwebassembly.WasmException;
  * 
  * @author Volker Berlin
  */
-public class FunctionManager {
+class FunctionManager {
 
     private final Map<FunctionName, FunctionState> states = new LinkedHashMap<>();
 

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

@@ -46,7 +46,6 @@ import de.inetsoftware.jwebassembly.wasm.AnyType;
 import de.inetsoftware.jwebassembly.wasm.NamedStorageType;
 import de.inetsoftware.jwebassembly.wasm.StructOperator;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 import de.inetsoftware.jwebassembly.watparser.WatParser;
 
 /**

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

@@ -33,7 +33,6 @@ import de.inetsoftware.jwebassembly.wasm.StructOperator;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
 import de.inetsoftware.jwebassembly.wasm.VariableOperator;
 import de.inetsoftware.jwebassembly.wasm.WasmBlockOperator;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 
 /**
  * Module Writer base class.

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

@@ -27,14 +27,13 @@ import javax.annotation.Nonnull;
 
 import de.inetsoftware.jwebassembly.api.annotation.WasmTextCode;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 
 /**
  * Handle all the constant strings. The constant strings will be write into the data section.
  * 
  * @author Volker Berlin
  */
-public class StringManager extends LinkedHashMap<String, Integer> {
+class StringManager extends LinkedHashMap<String, Integer> {
 
     /**
      * Signature of method stringConstant.
@@ -54,7 +53,7 @@ public class StringManager extends LinkedHashMap<String, Integer> {
      * @param options
      *            compiler properties and shared managers
      */
-    public StringManager( WasmOptions options ) {
+    StringManager( WasmOptions options ) {
         this.functions = options.functions;
     }
 

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

@@ -23,6 +23,8 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
+import javax.annotation.Nonnull;
+
 import de.inetsoftware.classparser.ClassFile;
 import de.inetsoftware.classparser.ClassFile.Type;
 import de.inetsoftware.classparser.ConstantClass;
@@ -34,7 +36,6 @@ import de.inetsoftware.jwebassembly.wasm.AnyType;
 import de.inetsoftware.jwebassembly.wasm.ArrayType;
 import de.inetsoftware.jwebassembly.wasm.NamedStorageType;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 
 /**
  * Manage the written and to write types (classes)
@@ -60,7 +61,7 @@ public class TypeManager {
      * @param options
      *            compiler properties
      */
-    public TypeManager( WasmOptions options ) {
+    TypeManager( WasmOptions options ) {
         this.options = options;
     }
 
@@ -87,7 +88,7 @@ public class TypeManager {
      * Get the StructType. If needed an instance is created.
      * 
      * @param name
-     *            the type name
+     *            the type name like java/lang/Object
      * @return the struct type
      */
     public StructType valueOf( String name ) {
@@ -123,6 +124,24 @@ public class TypeManager {
         return type;
     }
 
+    /**
+     * Get the FunctionName for a virtual call and mark it as used. The function has 2 parameters (THIS,
+     * virtualfunctionIndex) and returns the index of the function.
+     * 
+     * @return the name
+     */
+    @Nonnull
+    WatCodeSyntheticFunctionName getCallVirtualGC() {
+        return new WatCodeSyntheticFunctionName( //
+                        "callVirtual", "local.get 0 " // THIS
+                                        + "struct.get java/lang/Object .vtable " // vtable is on index 0
+                                        + "local.get 1 " // virtualFunctionIndex
+                                        + "i32.add " //
+                                        + "i32.load offset=0 align=4 " //
+                                        + "return " //
+                        , valueOf( "java/lang/Object" ), ValueType.i32, null, ValueType.i32 ); //
+    }
+
     /**
      * A reference to a type.
      * 

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

@@ -22,12 +22,7 @@ import javax.annotation.Nonnull;
 
 import de.inetsoftware.jwebassembly.WasmException;
 import de.inetsoftware.jwebassembly.module.TypeManager.StructType;
-import de.inetsoftware.jwebassembly.wasm.MemoryOperator;
-import de.inetsoftware.jwebassembly.wasm.NamedStorageType;
-import de.inetsoftware.jwebassembly.wasm.StructOperator;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
-import de.inetsoftware.jwebassembly.wasm.VariableOperator;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 
 /**
  * WasmInstruction for a function call.

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

@@ -26,7 +26,6 @@ import de.inetsoftware.jwebassembly.wasm.NamedStorageType;
 import de.inetsoftware.jwebassembly.wasm.StructOperator;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
 import de.inetsoftware.jwebassembly.wasm.VariableOperator;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 
 /**
  * WasmInstruction for a function call.
@@ -96,14 +95,9 @@ class WasmCallVirtualInstruction extends WasmCallIndirectInstruction {
             // duplicate this on the stack
             writer.writeLocal( VariableOperator.get, getVariableIndexOfThis() );
 
+            writer.writeConst( virtualFunctionIdx * 4, ValueType.i32 );
+            writer.writeFunctionCall( options.getCallVirtual() );
             StructType type = getThisType();
-            if( options.useGC() ) {
-                writer.writeStructOperator( StructOperator.GET, type, new NamedStorageType( type, "", "vtable" ), 0 ); // vtable is ever on position 0
-            } else {
-                writer.writeConst( 0, ValueType.i32 ); // vtable is ever on position 0
-                writer.writeFunctionCall( WasmCodeBuilder.GET_I32 );
-            }
-            writer.writeMemoryOperator( MemoryOperator.load, ValueType.i32, virtualFunctionIdx * 4, 2 );
             writer.writeVirtualFunctionCall( getFunctionName(), type );
         }
     }

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

@@ -44,7 +44,6 @@ import de.inetsoftware.jwebassembly.wasm.ValueType;
 import de.inetsoftware.jwebassembly.wasm.ValueTypeParser;
 import de.inetsoftware.jwebassembly.wasm.VariableOperator;
 import de.inetsoftware.jwebassembly.wasm.WasmBlockOperator;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 
 /**
  * Base class for Code Building.
@@ -517,6 +516,7 @@ public abstract class WasmCodeBuilder {
      */
     protected void addCallVirtualInstruction( FunctionName name, int javaCodePos, int lineNumber ) {
         addCallIndirectInstruction( new WasmCallVirtualInstruction( name, javaCodePos, lineNumber, types, options ) );
+        options.getCallVirtual(); // mark the function as needed
     }
 
     /**
@@ -629,7 +629,7 @@ public abstract class WasmCodeBuilder {
     }
 
     /**
-     * Add an array operation to the instruction list as marker on the code position.
+     * Add a struct/object operation to the instruction list.
      * 
      * @param op
      *            the operation

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

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package de.inetsoftware.jwebassembly.wasm;
+package de.inetsoftware.jwebassembly.module;
 
 import java.util.HashMap;
 
@@ -33,13 +33,13 @@ import de.inetsoftware.jwebassembly.module.TypeManager;
  */
 public class WasmOptions {
 
-    public final FunctionManager functions = new FunctionManager();
+    final FunctionManager functions = new FunctionManager();
 
-    public final TypeManager     types     = new TypeManager( this );
+    final TypeManager     types     = new TypeManager( this );
 
-    public final StringManager   strings   = new StringManager( this );
+    final StringManager   strings   = new StringManager( this );
 
-    public final CodeOptimizer   optimizer = new CodeOptimizer();
+    final CodeOptimizer   optimizer = new CodeOptimizer();
 
     private final boolean debugNames;
 
@@ -55,6 +55,9 @@ public class WasmOptions {
      */
     public FunctionName ref_eq;
 
+
+    private FunctionName callVirtual;
+
     /**
      * Create a new instance of options
      * 
@@ -108,4 +111,20 @@ public class WasmOptions {
     public String getSourceMapBase() {
         return sourceMapBase;
     }
+
+    /**
+     * Get the FunctionName for a virtual call and mark it as used. The function has 2 parameters (THIS,
+     * virtualfunctionIndex) and returns the index of the function.
+     * 
+     * @return the name
+     */
+    @Nonnull
+    FunctionName getCallVirtual() {
+        FunctionName name = callVirtual;
+        if( name == null ) {
+            callVirtual = name = types.getCallVirtualGC();
+            functions.markAsNeeded( name );
+        }
+        return name;
+    }
 }

src/de/inetsoftware/jwebassembly/text/TextModuleWriter.java

@@ -33,6 +33,7 @@ import de.inetsoftware.jwebassembly.module.FunctionName;
 import de.inetsoftware.jwebassembly.module.ModuleWriter;
 import de.inetsoftware.jwebassembly.module.TypeManager.StructType;
 import de.inetsoftware.jwebassembly.module.ValueTypeConvertion;
+import de.inetsoftware.jwebassembly.module.WasmOptions;
 import de.inetsoftware.jwebassembly.module.WasmTarget;
 import de.inetsoftware.jwebassembly.wasm.AnyType;
 import de.inetsoftware.jwebassembly.wasm.ArrayOperator;
@@ -43,7 +44,6 @@ import de.inetsoftware.jwebassembly.wasm.StructOperator;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
 import de.inetsoftware.jwebassembly.wasm.VariableOperator;
 import de.inetsoftware.jwebassembly.wasm.WasmBlockOperator;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 
 /**
  * Module Writer for text format with S-expressions.

src/de/inetsoftware/jwebassembly/watparser/WatParser.java

@@ -28,8 +28,12 @@ import de.inetsoftware.jwebassembly.WasmException;
 import de.inetsoftware.jwebassembly.module.FunctionName;
 import de.inetsoftware.jwebassembly.module.ValueTypeConvertion;
 import de.inetsoftware.jwebassembly.module.WasmCodeBuilder;
+import de.inetsoftware.jwebassembly.module.TypeManager.StructType;
+import de.inetsoftware.jwebassembly.wasm.AnyType;
 import de.inetsoftware.jwebassembly.wasm.MemoryOperator;
+import de.inetsoftware.jwebassembly.wasm.NamedStorageType;
 import de.inetsoftware.jwebassembly.wasm.NumericOperator;
+import de.inetsoftware.jwebassembly.wasm.StructOperator;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
 import de.inetsoftware.jwebassembly.wasm.VariableOperator;
 import de.inetsoftware.jwebassembly.wasm.WasmBlockOperator;
@@ -246,6 +250,24 @@ public class WatParser extends WasmCodeBuilder {
                     case "i32.load8_u":
                         i = addMemoryInstruction( MemoryOperator.load8_u, ValueType.i32, tokens, i, lineNumber );
                         break;
+                    case "struct.get":
+                        String typeName = get( tokens, ++i );
+                        String fieldName = get( tokens, ++i );
+                        NamedStorageType fieldNameType = null;
+                        List<NamedStorageType> fields = getTypeManager().valueOf( typeName ).getFields();
+                        if( fields != null ) { // field is null on prepare
+                            for( NamedStorageType namedStorageType : fields ) {
+                                if( namedStorageType.getName().equals( fieldName ) ) {
+                                    fieldNameType = namedStorageType;
+                                    break;
+                                }
+                            }
+                        }
+                        if( fieldNameType == null ) {
+                            fieldNameType = new NamedStorageType( ValueType.anyref, "", fieldName );
+                        }
+                        addStructInstruction( StructOperator.GET, typeName, fieldNameType, javaCodePos, lineNumber );
+                        break;
                     default:
                         throw new WasmException( "Unknown WASM token: " + tok, lineNumber );
                 }

test/de/inetsoftware/jwebassembly/module/WatParserTest.java

@@ -28,7 +28,6 @@ import org.junit.Test;
 import de.inetsoftware.jwebassembly.WasmException;
 import de.inetsoftware.jwebassembly.binary.BinaryModuleWriter;
 import de.inetsoftware.jwebassembly.text.TextModuleWriter;
-import de.inetsoftware.jwebassembly.wasm.WasmOptions;
 import de.inetsoftware.jwebassembly.watparser.WatParser;
 
 /**