[Truffle] Remove MODULE_FUNCTION_FLAG_FRAME_SLOT_ID.

* Since it is exclusive with other visibilities, we use the VISIBILITY_FRAME_SLOT_ID instead.

core/src/main/java/org/jruby/truffle/nodes/core/ModuleNodes.java

@@ -947,44 +947,11 @@ public ModuleFunctionNode(ModuleFunctionNode prev) {
         }
 
         @Specialization
-        public RubyNilClass moduleFunction(RubyModule module, Object... args) {
+        public RubyModule moduleFunction(RubyModule module, Object... args) {
             notDesignedForCompilation();
 
-            if (args.length == 0) {
-                final Frame unpacked = Truffle.getRuntime().getCallerFrame().getFrame(FrameInstance.FrameAccess.READ_WRITE, false);
-
-                final FrameSlot slot = unpacked.getFrameDescriptor().findFrameSlot(RubyModule.MODULE_FUNCTION_FLAG_FRAME_SLOT_ID);
-
-                /*
-                 * setObject, even though it's a boolean, so we can getObject and either get the
-                 * default Nil or the boolean value without triggering deoptimization.
-                 */
-
-                unpacked.setObject(slot, true);
-            } else {
-                for (Object argument : args) {
-                    final String methodName;
-
-                    if (argument instanceof RubySymbol) {
-                        methodName = ((RubySymbol) argument).toString();
-                    } else if (argument instanceof RubyString) {
-                        methodName = ((RubyString) argument).toString();
-                    } else {
-                        throw new UnsupportedOperationException();
-                    }
-
-                    // TODO(cs): make this instance method private
-                    final RubyMethod method = ModuleOperations.lookupMethod(module, methodName);
-
-                    if (method == null) {
-                        throw new UnsupportedOperationException();
-                    }
-
-                    module.getSingletonClass(this).addMethod(this, method.withVisibility(Visibility.PUBLIC));
-                }
-            }
-
-            return getContext().getCoreLibrary().getNilObject();
+            module.visibilityMethod(this, args, Visibility.MODULE_FUNCTION);
+            return module;
         }
     }
 

core/src/main/java/org/jruby/truffle/nodes/methods/AddMethodNode.java

@@ -9,8 +9,6 @@
  */
 package org.jruby.truffle.nodes.methods;
 
-import com.oracle.truffle.api.frame.FrameSlot;
-import com.oracle.truffle.api.frame.FrameSlotTypeException;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.source.SourceSection;
 import org.jruby.runtime.Visibility;
@@ -24,12 +22,12 @@
 public class AddMethodNode extends RubyNode {
 
     @Child protected RubyNode receiver;
-    @Child protected MethodDefinitionNode method;
+    @Child protected MethodDefinitionNode methodNode;
 
     public AddMethodNode(RubyContext context, SourceSection section, RubyNode receiver, MethodDefinitionNode method, boolean topLevel) {
         super(context, section);
         this.receiver = receiver;
-        this.method = method;
+        this.methodNode = method;
     }
 
     @Override
@@ -38,7 +36,7 @@ public RubySymbol execute(VirtualFrame frame) {
 
         final Object receiverObject = receiver.execute(frame);
 
-        final RubyMethod methodObject = (RubyMethod) method.execute(frame);
+        final RubyMethod methodObject = (RubyMethod) methodNode.execute(frame);
 
         RubyModule module;
 
@@ -48,33 +46,15 @@ public RubySymbol execute(VirtualFrame frame) {
             module = ((RubyBasicObject) receiverObject).getSingletonClass(this);
         }
 
-        final RubyMethod methodWithDeclaringModule = methodObject.withDeclaringModule(module);
+        final RubyMethod method = methodObject.withDeclaringModule(module);
 
-        if (moduleFunctionFlag(frame)) {
-            module.addMethod(this, methodWithDeclaringModule.withVisibility(Visibility.PRIVATE));
-            module.getSingletonClass(this).addMethod(this, methodWithDeclaringModule.withVisibility(Visibility.PUBLIC));
+        if (method.getVisibility() == Visibility.MODULE_FUNCTION) {
+            module.addMethod(this, method.withVisibility(Visibility.PRIVATE));
+            module.getSingletonClass(this).addMethod(this, method.withVisibility(Visibility.PUBLIC));
         } else {
-            module.addMethod(this, methodWithDeclaringModule);
+            module.addMethod(this, method);
         }
 
         return getContext().newSymbol(method.getName());
     }
-
-    private boolean moduleFunctionFlag(VirtualFrame frame) {
-        final FrameSlot moduleFunctionFlagSlot = frame.getFrameDescriptor().findFrameSlot(RubyModule.MODULE_FUNCTION_FLAG_FRAME_SLOT_ID);
-
-        if (moduleFunctionFlagSlot == null) {
-            return false;
-        } else {
-            Object moduleFunctionObject;
-
-            try {
-                moduleFunctionObject = frame.getObject(moduleFunctionFlagSlot);
-            } catch (FrameSlotTypeException e) {
-                throw new RuntimeException(e);
-            }
-
-            return (moduleFunctionObject instanceof Boolean) && (boolean) moduleFunctionObject;
-        }
-    }
 }

core/src/main/java/org/jruby/truffle/runtime/core/RubyModule.java

@@ -81,12 +81,6 @@ public static void debugModuleChain(RubyModule module) {
      */
     public static final Object VISIBILITY_FRAME_SLOT_ID = new Object();
 
-    /**
-     * The slot within a module definition method frame where we store the implicit state that is
-     * the flag for whether or not new methods will be module methods (functions is the term).
-     */
-    public static final Object MODULE_FUNCTION_FLAG_FRAME_SLOT_ID = new Object();
-
     // The context is stored here - objects can obtain it via their class (which is a module)
     private final RubyContext context;
 
@@ -388,6 +382,8 @@ public void visibilityMethod(RubyNode currentNode, Object[] arguments, Visibilit
 
                 if (arg instanceof RubySymbol) {
                     methodName = ((RubySymbol) arg).toString();
+                } else if (arg instanceof RubyString) {
+                    methodName = ((RubyString) arg).toString();
                 } else {
                     throw new UnsupportedOperationException();
                 }
@@ -399,12 +395,17 @@ public void visibilityMethod(RubyNode currentNode, Object[] arguments, Visibilit
                 }
 
                 /*
-                 * If the method was already defined in this class, that's fine {@link addMethod}
-                 * will overwrite it, otherwise we do actually want to add a copy of the method with
-                 * a different visibility to this module.
+                 * If the method was already defined in this class, that's fine
+                 * {@link addMethod} will overwrite it, otherwise we do actually
+                 * want to add a copy of the method with a different visibility
+                 * to this module.
                  */
-
-                addMethod(currentNode, method.withVisibility(visibility));
+                if (visibility == Visibility.MODULE_FUNCTION) {
+                    addMethod(currentNode, method.withVisibility(Visibility.PRIVATE));
+                    getSingletonClass(currentNode).addMethod(currentNode, method.withVisibility(Visibility.PUBLIC));
+                } else {
+                    addMethod(currentNode, method.withVisibility(visibility));
+                }
             }
         }
     }

core/src/main/java/org/jruby/truffle/runtime/methods/RubyMethod.java

@@ -12,6 +12,7 @@
 import com.oracle.truffle.api.CallTarget;
 import com.oracle.truffle.api.frame.MaterializedFrame;
 import com.oracle.truffle.api.nodes.Node;
+
 import org.jruby.runtime.Visibility;
 import org.jruby.truffle.runtime.core.RubyClass;
 import org.jruby.truffle.runtime.core.RubyModule;
@@ -115,7 +116,7 @@ public boolean isVisibleTo(Node currentNode, RubyClass callerClass) {
                 return false;
 
             default:
-                return false;
+                throw new UnsupportedOperationException(visibility.name());
         }
     }
 

core/src/main/java/org/jruby/truffle/translator/TranslatorEnvironment.java

@@ -201,7 +201,6 @@ public boolean getNeverAssignInParentScope() {
 
     public void addMethodDeclarationSlots() {
         frameDescriptor.addFrameSlot(RubyModule.VISIBILITY_FRAME_SLOT_ID);
-        frameDescriptor.addFrameSlot(RubyModule.MODULE_FUNCTION_FLAG_FRAME_SLOT_ID);
     }
 
     public SharedMethodInfo getSharedMethodInfo() {