fixup! Introduce VMAccess API

Author: gilles-duboscq

espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalConstantReflectionProvider.java

@@ -155,12 +155,12 @@ static EspressoResolvedJavaType classAsType(Value value, EspressoExternalVMAcces
                 dimensions++;
                 elemental = elemental.invokeMember("getComponentType");
             } while (elemental.invokeMember("isArray").asBoolean());
-            return new EspressoExternalResolvedArrayType(getElementalType(elemental, access), dimensions, access);
+            return new EspressoExternalResolvedArrayType(getNonArrayType(elemental, access), dimensions, access);
         }
-        return getElementalType(value, access);
+        return getNonArrayType(value, access);
     }
 
-    private static EspressoResolvedJavaType getElementalType(Value value, EspressoExternalVMAccess access) {
+    private static EspressoResolvedJavaType getNonArrayType(Value value, EspressoExternalVMAccess access) {
         if (value.invokeMember("isPrimitive").asBoolean()) {
             return getPrimitiveType(value.getMember("static").getMetaQualifiedName(), access);
         }

espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalResolvedInstanceType.java

@@ -41,6 +41,9 @@
 
 final class EspressoExternalResolvedInstanceType extends AbstractEspressoResolvedInstanceType {
     private final EspressoExternalVMAccess access;
+    /**
+     * A handle to an espresso Klass.
+     */
     private final Value metaObject;
     private final int flags;
     private EspressoExternalConstantPool constantPool;

espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalResolvedJavaMethod.java

@@ -276,6 +276,10 @@ JavaConstant invoke(JavaConstant receiver, JavaConstant... arguments) {
         for (int i = 0; i < parameterCount; i++) {
             JavaConstant argument = arguments[i];
             JavaKind argumentKind = argument.getJavaKind();
+            /*
+             * Perform widening primitive conversions (JLS 5.1.2) in order to implement strict
+             * method invocation conversions (JLS 5.3). Also promote to stack kind.
+             */
             args[i + outputArgumentOffset] = switch (signature.getParameterKind(i)) {
                 case Boolean -> switch (argumentKind) {
                     case Boolean -> argument.asBoolean() ? 1 : 0;
@@ -335,7 +339,7 @@ JavaConstant invoke(JavaConstant receiver, JavaConstant... arguments) {
         }
         Value result;
         try {
-            result = methodMirror.invokeMember("invoke", args);
+            result = methodMirror.execute(args);
         } catch (PolyglotException e) {
             throw new InvocationException(new EspressoExternalObjectConstant(access, e.getGuestObject()), e);
         }

espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/impl/Method.java

@@ -2164,8 +2164,7 @@ public RuntimeConstantPool getPool() {
     // endregion jdwp-specific
 
     private static final KeysArray<String> ALL_MEMBERS;
-    private static final Set<String> INVOCABLE_MEMBERS;
-    private static final Set<String> READABLE_MEMBERS;
+    private static final Set<String> ALL_MEMBERS_SET;
 
     static {
         String[] readableMembers = {
@@ -2185,15 +2184,8 @@ public RuntimeConstantPool getPool() {
                         ReadMember.HAS_POISON,
                         ReadMember.HOLDER,
         };
-        String[] invocableMembers = {
-                        InvokeMember.INVOKE,
-        };
-        String[] allMembers = new String[readableMembers.length + invocableMembers.length];
-        System.arraycopy(readableMembers, 0, allMembers, 0, readableMembers.length);
-        System.arraycopy(invocableMembers, 0, allMembers, readableMembers.length, invocableMembers.length);
-        ALL_MEMBERS = new KeysArray<>(allMembers);
-        READABLE_MEMBERS = Set.of(readableMembers);
-        INVOCABLE_MEMBERS = Set.of(invocableMembers);
+        ALL_MEMBERS = new KeysArray<>(readableMembers);
+        ALL_MEMBERS_SET = Set.of(readableMembers);
     }
 
     @ExportMessage
@@ -2365,12 +2357,18 @@ public static Object doUnknown(@SuppressWarnings("unused") Method receiver, Stri
         }
     }
 
+    /*
+     * We use the "execute" message on Method objects instead of the usual way of invoking espresso
+     * over interop because usual interop cannot call private methods. For instance methods interop
+     * also only returns "bound" methods for a specific receiver. Also, this "execute" message is
+     * much more restrictive in what arguments it accepts: it only expects host boxes for primitive
+     * arguments and espresso objects for object arguments. It doesn't perform any of the more
+     * complex conversions typically done for interop.
+     */
     @ExportMessage
-    abstract static class InvokeMember {
-        static final String INVOKE = "invoke";
-
-        @Specialization(guards = "INVOKE.equals(member)")
-        static Object invoke(Method receiver, @SuppressWarnings("unused") String member, Object[] arguments,
+    abstract static class Execute {
+        @Specialization
+        static Object invoke(Method receiver, Object[] arguments,
                         @Bind Node node,
                         @CachedLibrary(limit = "2") @Exclusive InteropLibrary interop,
                         @Cached @Exclusive InlinedBranchProfile typeError,
@@ -2479,26 +2477,20 @@ static Object invoke(Method receiver, @SuppressWarnings("unused") String member,
             }
             return result;
         }
-
-        @Fallback
-        @SuppressWarnings("unused")
-        static Object doUnknown(Method receiver, String member, Object[] arguments) throws UnknownIdentifierException {
-            throw UnknownIdentifierException.create(member);
-        }
     }
 
     @ExportMessage
     @SuppressWarnings("static-method")
     @TruffleBoundary
     public boolean isMemberReadable(String member) {
-        return READABLE_MEMBERS.contains(member);
+        return ALL_MEMBERS_SET.contains(member);
     }
 
     @ExportMessage
     @SuppressWarnings("static-method")
     @TruffleBoundary
-    public boolean isMemberInvocable(String member) {
-        return INVOCABLE_MEMBERS.contains(member);
+    public boolean isExecutable() {
+        return true;
     }
 
     @ExportMessage