[GR-23797] Update Marshal.dump to raise an error when an object has singleton methods

PullRequest: truffleruby/3263

Author: bjfish

CHANGELOG.md

@@ -9,6 +9,7 @@ Bug fixes:
 
 Compatibility:
 
+* Fix `Marshal.dump` to raise an error when an object has singleton methods (@bjfish).
 
 Performance:
 

spec/tags/core/marshal/dump_tags.txt

@@ -1,4 +1,3 @@
-fails:Marshal.dump with an Object raises if an Object has a singleton class and singleton methods
 fails(immutable regexp):Marshal.dump with a Regexp dumps a Regexp with instance variables
 fails(immutable regexp):Marshal.dump with a Regexp dumps an extended Regexp
 fails(immutable regexp):Marshal.dump with a Regexp dumps a Regexp subclass

src/main/java/org/truffleruby/core/kernel/KernelNodes.java

@@ -1629,6 +1629,24 @@ protected RubyArray singletonMethods(Object self, boolean includeAncestors,
 
     }
 
+    @Primitive(name = "singleton_methods?")
+    public abstract static class HasSingletonMethodsNode extends PrimitiveArrayArgumentsNode {
+
+        @TruffleBoundary
+        @Specialization
+        protected boolean hasSingletonMethods(Object self,
+                @Cached MetaClassNode metaClassNode) {
+            final RubyClass metaClass = metaClassNode.execute(self);
+
+            if (!metaClass.isSingleton) {
+                return false;
+            }
+
+            return metaClass.fields.anyMethodDefined();
+        }
+
+    }
+
     @NodeChild(value = "duration", type = RubyBaseNodeWithExecute.class)
     @CoreMethod(names = "sleep", isModuleFunction = true, optional = 1)
     public abstract static class SleepNode extends CoreMethodNode {

src/main/java/org/truffleruby/core/module/ModuleFields.java

@@ -1047,6 +1047,15 @@ public Collection<RubySymbol> filterMethods(
         return filtered;
     }
 
+    public boolean anyMethodDefined() {
+        for (var value : methods.values()) {
+            if (value.getMethod() != null) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     private Map<String, InternalMethod> getInternalMethodMap() {
         Map<String, InternalMethod> map = new HashMap<>();
         for (Entry<String, MethodEntry> e : methods.entrySet()) {

src/main/ruby/truffleruby/core/marshal.rb

@@ -1013,6 +1013,7 @@ def serialize(obj)
     end
 
     def serialize_extended_object(obj)
+      raise TypeError, "singleton can't be dumped" if Primitive.singleton_methods?(obj)
       str = +''
       Primitive.vm_extended_modules obj, -> mod do
         str << "e#{serialize(mod.name.to_sym)}"