[Truffle] Reimplemented the :module_mirror primitive in Ruby to simplify corner cases.

Author: nirvdrum

truffle/src/main/java/org/jruby/truffle/nodes/rubinius/ModulePrimitiveNodes.java

@@ -9,49 +9,33 @@
  */
 package org.jruby.truffle.nodes.rubinius;
 
-import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
-import com.oracle.truffle.api.dsl.Cached;
+import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.dsl.Specialization;
+import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.source.SourceSection;
-import org.jruby.truffle.runtime.RubyConstant;
+import org.jruby.truffle.nodes.dispatch.CallDispatchHeadNode;
+import org.jruby.truffle.nodes.dispatch.DispatchHeadNodeFactory;
 import org.jruby.truffle.runtime.RubyContext;
-import org.jruby.truffle.runtime.core.RubyBasicObject;
-import org.jruby.truffle.runtime.core.RubyClass;
-import org.jruby.truffle.runtime.core.RubyModule;
-
 
 public abstract class ModulePrimitiveNodes {
 
     @RubiniusPrimitive(name = "module_mirror")
     public abstract static class ModuleMirrorPrimitiveNode extends RubiniusPrimitiveNode {
 
+        @Child private CallDispatchHeadNode moduleMirrorNode;
+
         public ModuleMirrorPrimitiveNode(RubyContext context, SourceSection sourceSection) {
             super(context, sourceSection);
         }
 
-        @Specialization(guards = "logicalClass == object.getLogicalClass()")
-        public Object moduleMirrorCached(RubyBasicObject object,
-                                             @Cached("object.getLogicalClass()") RubyClass logicalClass,
-                                             @Cached("lookupMirror(object)") Object mirror) {
-            return mirror;
-        }
-
         @Specialization
-        public Object moduleMirrorUncached(RubyBasicObject object) {
-            return lookupMirror(object);
-        }
-
-        @TruffleBoundary
-        protected Object lookupMirror(RubyBasicObject object) {
-            final RubyModule rubinius = (RubyModule) getContext().getCoreLibrary().getObjectClass().getConstants().get("Rubinius").getValue();
-            final RubyModule mirror = (RubyModule) rubinius.getConstants().get("Mirror").getValue();
-            final RubyConstant objectMirrorConstant = mirror.getConstants().get(object.getLogicalClass().getName());
-
-            if (objectMirrorConstant == null) {
-                return nil();
+        public Object moduleMirrorCached(VirtualFrame frame, Object reflectee) {
+            if (moduleMirrorNode == null) {
+                CompilerDirectives.transferToInterpreter();
+                moduleMirrorNode = insert(DispatchHeadNodeFactory.createMethodCall(getContext(), null));
             }
 
-            return objectMirrorConstant.getValue();
+            return moduleMirrorNode.call(frame, getContext().getCoreLibrary().getRubiniusMirror(), "module_mirror", null, reflectee);
         }
 
     }

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

@@ -124,6 +124,7 @@ public class CoreLibrary {
     private final RubyModule kernelModule;
     private final RubyModule rubiniusModule;
     private final RubyModule rubiniusFFIModule;
+    private final RubyClass rubiniusMirrorModule;
     private final RubyModule signalModule;
     private final RubyModule truffleModule;
     private final RubyClass bigDecimalClass;
@@ -356,6 +357,8 @@ public CoreLibrary(RubyContext context) {
         rubiniusFFIModule = defineModule(rubiniusModule, "FFI");
         defineModule(defineModule(rubiniusFFIModule, "Platform"), "POSIX");
         defineClass(rubiniusFFIModule, objectClass, "Pointer", new PointerPrimitiveNodes.PointerAllocator());
+
+        rubiniusMirrorModule = defineClass(rubiniusModule, objectClass, "Mirror");
         defineModule(rubiniusModule, "Type");
 
         byteArrayClass = defineClass(rubiniusModule, objectClass, "ByteArray");
@@ -1387,6 +1390,10 @@ public RubyClass getTupleClass() {
         return tupleClass;
     }
 
+    public RubyClass getRubiniusMirror() {
+        return rubiniusMirrorModule;
+    }
+
     public RubyBasicObject getRubiniusUndefined() {
         return rubiniusUndefined;
     }

truffle/src/main/ruby/core.rb

@@ -16,6 +16,7 @@
 
 # Patch rubinius-core-api to make it work for us
 
+require_relative 'core/rubinius/api/shims/mirror'
 require_relative 'core/rubinius/api/shims/lookuptable'
 require_relative 'core/rubinius/api/shims/array'
 require_relative 'core/rubinius/api/shims/rubinius'

truffle/src/main/ruby/core/rubinius/api/shims/mirror.rb

@@ -0,0 +1,27 @@
+# Copyright (c) 2015 Oracle and/or its affiliates. All rights reserved. This
+# code is released under a tri EPL/GPL/LGPL license. You can use it,
+# redistribute it and/or modify it under the terms of the:
+#
+# Eclipse Public License version 1.0
+# GNU General Public License version 2
+# GNU Lesser General Public License version 2.1
+
+module Rubinius
+  class Mirror
+
+    # Implementation of the :module_mirror Rubinius primitive.
+    def self.module_mirror(obj)
+      if obj.is_a?(::Numeric)
+        Rubinius::Mirror::Numeric
+      else
+        begin
+          Rubinius::Mirror.const_get(obj.class.name.to_sym, false)
+        rescue NameError
+          # TODO (nirvdrum 06-Jun-15) Rubinius defaults to Rubinius::Mirror::Object, but we don't have that yet. `nil` is safe based upon current usage.
+          nil
+        end
+      end
+    end
+
+  end
+end