Emit `warn` event for duplicated hash keys on ripper

Need to use `rb_warn` macro instead of calling `rb_compile_warn`
directly to emit `warn` event on ripper.

internal/parse.h

@@ -65,7 +65,6 @@ int rb_ruby_parser_end_seen_p(rb_parser_t *p);
 int rb_ruby_parser_set_yydebug(rb_parser_t *p, int flag);
 rb_parser_string_t *rb_str_to_parser_string(rb_parser_t *p, VALUE str);
 
-void rb_parser_warn_duplicate_keys(struct parser_params *p, NODE *hash);
 int rb_parser_dvar_defined_ref(struct parser_params*, ID, ID**);
 ID rb_parser_internal_id(struct parser_params*);
 int rb_parser_reg_fragment_check(struct parser_params*, rb_parser_string_t*, int);

parse.y

@@ -14890,7 +14890,6 @@ nd_type_st_key_enable_p(NODE *node)
     }
 }
 
-#ifndef RIPPER
 static VALUE
 nd_value(struct parser_params *p, NODE *node)
 {
@@ -14921,8 +14920,8 @@ nd_value(struct parser_params *p, NODE *node)
     }
 }
 
-void
-rb_parser_warn_duplicate_keys(struct parser_params *p, NODE *hash)
+static void
+warn_duplicate_keys(struct parser_params *p, NODE *hash)
 {
     /* See https://bugs.ruby-lang.org/issues/20331 for discussion about what is warned. */
     st_table *literal_keys = st_init_table_with_size(&literal_type, RNODE_LIST(hash)->as.nd_alen / 2);
@@ -14942,9 +14941,9 @@ rb_parser_warn_duplicate_keys(struct parser_params *p, NODE *hash)
             key = (st_data_t)head;
 
             if (st_delete(literal_keys, &key, &data)) {
-                rb_compile_warn(p->ruby_sourcefile, nd_line((NODE *)data),
-                                "key %+"PRIsVALUE" is duplicated and overwritten on line %d",
-                                nd_value(p, head), nd_line(head));
+                rb_warn2L(nd_line((NODE *)data),
+                          "key %+"PRIsWARN" is duplicated and overwritten on line %d",
+                          nd_value(p, head), WARN_I(nd_line(head)));
             }
             st_insert(literal_keys, (st_data_t)key, (st_data_t)hash);
         }
@@ -14952,12 +14951,11 @@ rb_parser_warn_duplicate_keys(struct parser_params *p, NODE *hash)
     }
     st_free_table(literal_keys);
 }
-#endif
 
 static NODE *
 new_hash(struct parser_params *p, NODE *hash, const YYLTYPE *loc)
 {
-    if (hash) rb_parser_warn_duplicate_keys(p, hash);
+    if (hash) warn_duplicate_keys(p, hash);
     return NEW_HASH(hash, loc);
 }
 

test/ripper/test_parser_events.rb

@@ -1686,6 +1686,12 @@ class TestRipper::ParserEvents < Test::Unit::TestCase
     assert_equal([3], args)
   end
 
+  def test_warn_duplicated_hash_keys
+    fmt, *args = warn("{ a: 1, a: 2 }")
+    assert_match(/is duplicated and overwritten on line/, fmt)
+    assert_equal([:a, 1], args)
+  end
+
   def test_warn_cr_in_middle
     fmt = nil
     assert_warn("") {fmt, = warn("\r;")}