From f87e43f23a7752b979d5f6dda6232dce3293aa55 Mon Sep 17 00:00:00 2001
From: Jeremy Evans <code@jeremyevans.net>
Date: Fri, 26 Jul 2019 16:11:33 -0700
Subject: [PATCH] Warn $; $, $/ $\ $. outside of ruby -e

Fixes [Bug #14240]
---
 parse.y                  | 14 +++++++++-----
 test/ruby/test_syntax.rb |  8 ++++++++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/parse.y b/parse.y
index 46c263fa7b..fe23d6ef98 100644
--- a/parse.y
+++ b/parse.y
@@ -8347,17 +8347,21 @@ parse_gvar(struct parser_params *p, const enum lex_state_e last_state)
 	pushback(p, c);
 	c = '_';
 	/* fall through */
+      case '/':         /* $/: input record separator */
+      case '\\':        /* $\: output record separator */
+      case ';':         /* $;: field separator */
+      case ',':         /* $,: output field separator */
+      case '.':         /* $.: last read line number */
+        if (c != '_' && strcmp(p->ruby_sourcefile, "-e")) {
+            rb_warn("global variable $%c is deprecated", c);
+        }
+	/* fall through */
       case '~':		/* $~: match-data */
       case '*':		/* $*: argv */
       case '$':		/* $$: pid */
       case '?':		/* $?: last status */
       case '!':		/* $!: error string */
       case '@':		/* $@: error position */
-      case '/':		/* $/: input record separator */
-      case '\\':		/* $\: output record separator */
-      case ';':		/* $;: field separator */
-      case ',':		/* $,: output field separator */
-      case '.':		/* $.: last read line number */
       case '=':		/* $=: ignorecase */
       case ':':		/* $:: load path */
       case '<':		/* $<: reading filename */
diff --git a/test/ruby/test_syntax.rb b/test/ruby/test_syntax.rb
index c5c3737b30..a8748462e4 100644
--- a/test/ruby/test_syntax.rb
+++ b/test/ruby/test_syntax.rb
@@ -605,6 +605,14 @@ def test_unassignable
     end
   end
 
+  def test_deprecated_global_variable
+    assert_warning(/global variable \$; is deprecated/) { eval('$;') }
+    assert_warning(/global variable \$, is deprecated/) { eval('$,') }
+    assert_warning(/global variable \$\/ is deprecated/) { eval('$/') }
+    assert_warning(/global variable \$\\ is deprecated/) { eval('$\\') }
+    assert_warning(/global variable \$\. is deprecated/) { eval('$.') }
+  end
+
   Bug7559 = '[ruby-dev:46737]'
 
   def test_lineno_command_call_quote
-- 
2.21.0