add fallback support for Array#[] with endless range and delete endless int range specialization

Author: Nicolas Laurent

src/main/java/org/truffleruby/core/array/ArrayIndexNode.java

@@ -77,26 +77,6 @@ protected DynamicObject slice(DynamicObject array, DynamicObject range, NotProvi
         }
     }
 
-    @Specialization(guards = "isIntEndlessRange(getContext(), range)")
-    protected DynamicObject endlessSlice(DynamicObject array, DynamicObject range, NotProvided len,
-            @Cached("createBinaryProfile()") ConditionProfile negativeBeginProfile,
-            @Cached("create()") ArrayReadSliceNormalizedNode readNormalizedSliceNode) {
-        final int size = getSize(array);
-        final int normalizedBegin = ArrayOperations
-                .normalizeIndex(size, (int) Layouts.OBJECT_RANGE.getBegin(range), negativeBeginProfile);
-
-        if (normalizedBegin < 0 || normalizedBegin > size) {
-            return nil();
-        } else {
-            if (size == normalizedBegin) {
-                return allocateObjectNode
-                        .allocate(Layouts.BASIC_OBJECT.getLogicalClass(array), ArrayStrategy.NULL_ARRAY_STORE, 0);
-            }
-
-            return readNormalizedSliceNode.executeReadSlice(array, normalizedBegin, size - normalizedBegin);
-        }
-    }
-
     @Specialization(guards = "isFallback(index, maybeLength)")
     protected Object fallbackIndex(DynamicObject array, Object index, Object maybeLength) {
         return fallback(array, index, maybeLength);

src/main/java/org/truffleruby/language/RubyGuards.java

@@ -132,12 +132,6 @@ public static boolean isEndlessRange(RubyContext context, DynamicObject object)
         return isNil(context, Layouts.OBJECT_RANGE.getEnd(object));
     }
 
-    public static boolean isIntEndlessRange(RubyContext context, DynamicObject object) {
-        return isObjectRange(object) && isInteger(Layouts.OBJECT_RANGE.getBegin(object)) && isEndlessRange(
-                context,
-                object);
-    }
-
     public static boolean isRubyRange(Object value) {
         return isIntRange(value) || isLongRange(value) || isObjectRange(value);
     }

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

@@ -153,15 +153,19 @@ def ==(other)
         unless arg.begin.respond_to?(:to_int)
           raise TypeError, "no implicit conversion of #{arg.begin.class} into Integer"
         end
-        unless arg.end.respond_to?(:to_int)
+        unless arg.end == nil || arg.end.respond_to?(:to_int)
           raise TypeError, "no implicit conversion of #{arg.end.class} into Integer"
         end
         start_index = arg.begin.to_int
-        end_index = arg.end.to_int
         Truffle::Type.check_long(start_index)
-        Truffle::Type.check_long(end_index)
         start_index = Truffle::Type.clamp_to_int(start_index)
-        end_index = Truffle::Type.clamp_to_int(end_index)
+        if arg.end == nil
+          end_index = arg.exclude_end? ? size : size - 1
+        else
+          end_index = arg.end.to_int
+          Truffle::Type.check_long(end_index)
+          end_index = Truffle::Type.clamp_to_int(end_index)
+        end
         range = Range.new(start_index, end_index, arg.exclude_end?)
         TrufflePrimitive.array_aref(self, range, undefined)
       else

test/mri/excludes/TestArray.rb

@@ -24,7 +24,6 @@
 exclude :test_union, "needs investigation"
 exclude :test_uniq_bang_with_freeze, "needs investigation"
 exclude :test_zip, "needs investigation"
-exclude :test_0_literal, "needs investigation"
 exclude :test_AREF, "needs investigation"
 exclude :test_combination_with_callcc, "needs investigation"
 exclude :test_fill_0, "needs investigation"