From a7e148fddfd912d75efcc63f87b00efebaed94e5 Mon Sep 17 00:00:00 2001
From: Kevin Menard <kevin@nirvdrum.com>
Date: Sat, 7 Mar 2015 15:33:38 -0500
Subject: [PATCH] Revert "[Truffle] Fixed class variable lookup from singleton
 classes by attaching their companion class to them."

This reverts commit 0e29b6b8c8f801f35a164b3382d0365b3ae37cb0.

The approach needs overall refinement.
---
 .../truffle/runtime/ModuleOperations.java     |  8 --------
 .../truffle/runtime/core/RubyBasicObject.java |  9 ++-------
 .../jruby/truffle/runtime/core/RubyClass.java | 19 +++----------------
 3 files changed, 5 insertions(+), 31 deletions(-)

diff --git a/truffle/src/main/java/org/jruby/truffle/runtime/ModuleOperations.java b/truffle/src/main/java/org/jruby/truffle/runtime/ModuleOperations.java
index a73be882e48..dc237008174 100644
--- a/truffle/src/main/java/org/jruby/truffle/runtime/ModuleOperations.java
+++ b/truffle/src/main/java/org/jruby/truffle/runtime/ModuleOperations.java
@@ -243,14 +243,6 @@ public static Object lookupClassVariable(RubyModule module, String name) {
             }
         }
 
-        if (module instanceof RubyClass) {
-            RubyClass klass = (RubyClass) module;
-
-            if (klass.isSingleton()) {
-                return lookupClassVariable(((RubyClass) module).getAttached(), name);
-            }
-        }
-
         // Nothing found
 
         return null;
diff --git a/truffle/src/main/java/org/jruby/truffle/runtime/core/RubyBasicObject.java b/truffle/src/main/java/org/jruby/truffle/runtime/core/RubyBasicObject.java
index 2af2b66e946..f06ae4339c0 100644
--- a/truffle/src/main/java/org/jruby/truffle/runtime/core/RubyBasicObject.java
+++ b/truffle/src/main/java/org/jruby/truffle/runtime/core/RubyBasicObject.java
@@ -104,13 +104,8 @@ public RubyClass getSingletonClass(Node currentNode) {
 
         final RubyClass logicalClass = metaClass;
 
-        if (this instanceof RubyModule) {
-            metaClass = RubyClass.createSingletonClassOfObject(getContext(), logicalClass, (RubyModule) this,
-                    String.format("#<Class:#<%s:0x%x>>", logicalClass.getName(), getObjectID()));
-        } else {
-            metaClass = RubyClass.createSingletonClassOfObject(getContext(), logicalClass, logicalClass,
-                    String.format("#<Class:#<%s:0x%x>>", logicalClass.getName(), getObjectID()));
-        }
+        metaClass = RubyClass.createSingletonClassOfObject(getContext(), logicalClass,
+                String.format("#<Class:#<%s:0x%x>>", logicalClass.getName(), getObjectID()));
 
         if (DebugOperations.verySlowIsFrozen(this)) {
             DebugOperations.verySlowFreeze(metaClass);
diff --git a/truffle/src/main/java/org/jruby/truffle/runtime/core/RubyClass.java b/truffle/src/main/java/org/jruby/truffle/runtime/core/RubyClass.java
index ecf9f440530..ac2c1e5f857 100644
--- a/truffle/src/main/java/org/jruby/truffle/runtime/core/RubyClass.java
+++ b/truffle/src/main/java/org/jruby/truffle/runtime/core/RubyClass.java
@@ -33,7 +33,6 @@ public class RubyClass extends RubyModule {
 
     private final boolean isSingleton;
     private final Set<RubyClass> subClasses = Collections.newSetFromMap(new WeakHashMap<RubyClass, Boolean>());
-    @CompilationFinal private RubyModule attached;
 
     /**
      * This constructor supports initialization and solves boot-order problems and should not
@@ -49,10 +48,10 @@ public RubyClass(RubyContext context, RubyModule lexicalParent, RubyClass superc
         ensureSingletonConsistency();
     }
 
-    protected static RubyClass createSingletonClassOfObject(RubyContext context, RubyClass superclass, RubyModule attached, String name) {
+    protected static RubyClass createSingletonClassOfObject(RubyContext context, RubyClass superclass, String name) {
         // We also need to create the singleton class of a singleton class for proper lookup and consistency.
         // See rb_singleton_class() documentation in MRI.
-        return new RubyClass(context, superclass.getLogicalClass(), null, superclass, name, true, attached).ensureSingletonConsistency();
+        return new RubyClass(context, superclass.getLogicalClass(), null, superclass, name, true).ensureSingletonConsistency();
     }
 
     protected RubyClass(RubyContext context, RubyClass classClass, RubyModule lexicalParent, RubyClass superclass, String name, boolean isSingleton) {
@@ -65,14 +64,6 @@ protected RubyClass(RubyContext context, RubyClass classClass, RubyModule lexica
         }
     }
 
-    protected RubyClass(RubyContext context, RubyClass classClass, RubyModule lexicalParent, RubyClass superclass, String name, boolean isSingleton, RubyModule attached) {
-        this(context, classClass, lexicalParent, superclass, name, isSingleton);
-
-        assert isSingleton == true;
-
-        this.attached = attached;
-    }
-
     public void initialize(RubyClass superclass) {
         unsafeSetSuperclass(superclass);
         ensureSingletonConsistency();
@@ -133,7 +124,7 @@ private RubyClass createOneSingletonClass() {
         }
 
         metaClass = new RubyClass(getContext(),
-                getLogicalClass(), null, singletonSuperclass, String.format("#<Class:%s>", getName()), true, this);
+                getLogicalClass(), null, singletonSuperclass, String.format("#<Class:%s>", getName()), true);
 
         return metaClass;
     }
@@ -146,10 +137,6 @@ public boolean isSingleton() {
         return isSingleton;
     }
 
-    public RubyModule getAttached() {
-        return attached;
-    }
-
     public RubyClass getSuperClass() {
         CompilerAsserts.neverPartOfCompilation();