add support for default methods

README.md

@@ -32,6 +32,7 @@ The project is currently not production ready but you can run already some tests
 * [x] invoke instance method calls
 * [ ] invoke interface method calls
 * [ ] invoke dynamic method calls (lambdas)
+* [x] invoke default method calls
 * [ ] String support
 * [ ] static constructors
 * [x] Optimizer - Optimize the WASM output of a single method after transpiling before writing to output

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

@@ -228,6 +228,24 @@ public class ModuleGenerator {
                     ConstantClass superClass = superClassFile.getSuperClass();
                     superClassFile = superClass == null ? null : classFileLoader.get( superClass.getName() );
                 }
+
+                // search if there is a default implementation in an interface
+                superClassFile = classFile;
+                while( superClassFile != null ) {
+                    for( ConstantClass iface : superClassFile.getInterfaces() ) {
+                        ClassFile iClassFile = classFileLoader.get( iface.getName() );
+                        MethodInfo method = iClassFile.getMethod( next.methodName, next.signature );
+                        if( method != null ) {
+                            FunctionName name = new FunctionName( method );
+                            functions.markAsNeeded( name );
+                            functions.setAlias( next, name );
+                            continue NEXT; // we have found a super method
+                        }
+                    }
+                    ConstantClass superClass = superClassFile.getSuperClass();
+                    superClassFile = superClass == null ? null : classFileLoader.get( superClass.getName() );
+                }
+
                 throw new WasmException( "Missing function: " + next.signatureName, -1 );
             }
         }

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

@@ -27,6 +27,7 @@ import java.util.Map;
 import javax.annotation.Nonnull;
 
 import de.inetsoftware.classparser.ClassFile;
+import de.inetsoftware.classparser.ClassFile.Type;
 import de.inetsoftware.classparser.ConstantClass;
 import de.inetsoftware.classparser.FieldInfo;
 import de.inetsoftware.classparser.MethodInfo;
@@ -231,6 +232,11 @@ public class TypeManager {
                 throw new WasmException( "Missing class: " + className, -1 );
             }
 
+            // interface does not need to resolve
+            if( classFile.getType() == Type.Interface ) {
+                return;
+            }
+
             {
                 // list all used fields
                 StructType type = types.structTypes.get( className );

test/de/inetsoftware/jwebassembly/runtime/StructsNonGC.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018 - 2019 Volker Berlin (i-net software)
+ * Copyright 2018 - 2020 Volker Berlin (i-net software)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,6 +49,7 @@ public class StructsNonGC extends AbstractBaseTest {
             addParam( list, script, "callVirtualMethod" );
             addParam( list, script, "useGlobalObject" );
             addParam( list, script, "multipleAssign" );
+            addParam( list, script, "getDefaultValue" );
         }
         rule.setTestParameters( list );
         return list;
@@ -136,9 +137,21 @@ public class StructsNonGC extends AbstractBaseTest {
             }
             return val.a;
         }
+
+        @Export
+        static int getDefaultValue() {
+            Abc2 val = new Abc2();
+            return val.getDefault();
+        }
     }
 
-    static class Abc {
+    interface TestDefault {
+        default int getDefault() {
+            return 7;
+        }
+    }
+
+    static class Abc implements TestDefault {
         int  a;
 
         long b;