Rewrote Range creation for 3.1.0 compatibility (frozen methods) and added a relevant spec case

Author: MattAlp

spec/ruby/language/range_spec.rb

@@ -19,6 +19,15 @@
     it "is frozen" do
       (42..).should.frozen?
     end
+
+    it "is not frozen if it is a subclass of Range" do
+      class ChildRange < Range; end
+      ChildRange.new(1, 2).should_not.frozen?
+    end
+
+    it "is not frozen if it is created through allocate" do
+      Range.allocate.should_not.frozen?
+    end
   end
 
   ruby_version_is "2.7" do

spec/tags/language/range_tags.txt

@@ -9,6 +9,7 @@
  */
 package org.truffleruby.core.range;
 
+import com.oracle.truffle.api.dsl.Bind;
 import com.oracle.truffle.api.profiles.LoopConditionProfile;
 import org.truffleruby.builtins.CoreMethod;
 import org.truffleruby.builtins.CoreMethodArrayArgumentsNode;
@@ -223,7 +224,8 @@ protected RubyObjectRange dup(RubyObjectRange range) {
                     getLanguage().objectRangeShape,
                     range.excludedEnd,
                     range.begin,
-                    range.end);
+                    range.end,
+                    range.frozen);
             AllocationTracing.trace(copy, this);
             return copy;
         }
@@ -546,16 +548,17 @@ protected RubyLongRange longRange(RubyClass rubyClass, long begin, long end, boo
             return range;
         }
 
-        @Specialization(guards = { "rubyClass != getRangeClass() || (!isImplicitLong(begin) || !isImplicitLong(end))" })
+        @Specialization(guards = { "nonStandardClass || (!isImplicitLong(begin) || !isImplicitLong(end))" })
         protected RubyObjectRange objectRange(RubyClass rubyClass, Object begin, Object end, boolean excludeEnd,
-                @Cached DispatchNode compare) {
+                @Cached DispatchNode compare, @Bind("rubyClass != getRangeClass()") boolean nonStandardClass) {
 
             if (compare.call(begin, "<=>", end) == nil && end != nil && begin != nil) {
                 throw new RaiseException(getContext(), coreExceptions().argumentError("bad value for range", this));
             }
 
             final Shape shape = getLanguage().objectRangeShape;
-            final RubyObjectRange range = new RubyObjectRange(rubyClass, shape, excludeEnd, begin, end);
+            final RubyObjectRange range = new RubyObjectRange(rubyClass, shape, excludeEnd, begin, end,
+                    !nonStandardClass);
             AllocationTracing.trace(range, this);
             return range;
         }
@@ -571,7 +574,7 @@ public abstract static class AllocateNode extends UnaryCoreMethodNode {
         @Specialization
         protected RubyObjectRange allocate(RubyClass rubyClass) {
             final Shape shape = getLanguage().objectRangeShape;
-            final RubyObjectRange range = new RubyObjectRange(rubyClass, shape, false, nil, nil);
+            final RubyObjectRange range = new RubyObjectRange(rubyClass, shape, false, nil, nil, false);
             AllocationTracing.trace(range, this);
             return range;
         }

src/main/java/org/truffleruby/core/range/RangeNodes.java

@@ -23,8 +23,14 @@ public final class RubyObjectRange extends RubyRange implements ObjectGraphNode
     public Object begin;
     public Object end;
 
-    public RubyObjectRange(RubyClass rubyClass, Shape shape, boolean excludedEnd, Object begin, Object end) {
-        super(rubyClass, shape, excludedEnd);
+    public RubyObjectRange(
+            RubyClass rubyClass,
+            Shape shape,
+            boolean excludedEnd,
+            Object begin,
+            Object end,
+            boolean frozen) {
+        super(rubyClass, shape, excludedEnd, frozen);
         this.begin = begin;
         this.end = end;
     }

src/main/java/org/truffleruby/core/range/RubyObjectRange.java

@@ -23,8 +23,7 @@ public abstract class RubyRange extends RubyDynamicObject {
     public boolean frozen;
 
     public RubyRange(RubyClass rubyClass, Shape shape, boolean excludedEnd) {
-        super(rubyClass, shape);
-        this.excludedEnd = excludedEnd;
+        this(rubyClass, shape, excludedEnd, true);
     }
 
     public RubyRange(RubyClass rubyClass, Shape shape, boolean excludedEnd, boolean frozen) {