parse.y: refine message for gvar w/o identitirs

* parse.y (parse_gvar): separate message for gvar without
  non-space characters from message for invalid identitirs.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50480 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed May 13 11:13:40 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* parse.y (parse_gvar): separate message for gvar without
+	  non-space characters from message for invalid identitirs.
+
 Tue May 12 22:18:27 2015  Masaki Matsushita <glass.saga@gmail.com>
 
 	* enum.c (enum_to_a): fix incompatibility introduced in r50457.

parse.y

@@ -7675,8 +7675,13 @@ parse_gvar(struct parser_params *parser, const enum lex_state_e last_state)
 
       default:
 	if (!parser_is_identchar()) {
-	    pushback(c);
-	    compile_error(PARSER_ARG "`$%c' is not allowed as a global variable name", c);
+	    if (c == -1 || ISSPACE(c)) {
+		compile_error(PARSER_ARG "`$' without identifiers is not allowed as a global variable name");
+	    }
+	    else {
+		pushback(c);
+		compile_error(PARSER_ARG "`$%c' is not allowed as a global variable name", c);
+	    }
 	    return 0;
 	}
       case '0':

test/ripper/test_parser_events.rb

@@ -1219,14 +1219,17 @@ class TestRipper::ParserEvents < Test::Unit::TestCase
   def test_invalid_instance_variable_name
     assert_equal("`@1' is not allowed as an instance variable name", compile_error('@1'))
     assert_equal("`@%' is not allowed as an instance variable name", compile_error('@%'))
+    assert_equal("`@' without identifiers is not allowed as an instance variable name", compile_error('@'))
   end
 
   def test_invalid_class_variable_name
     assert_equal("`@@1' is not allowed as a class variable name", compile_error('@@1'))
     assert_equal("`@@%' is not allowed as a class variable name", compile_error('@@%'))
+    assert_equal("`@@' without identifiers is not allowed as a class variable name", compile_error('@@'))
   end
 
   def test_invalid_global_variable_name
     assert_equal("`$%' is not allowed as a global variable name", compile_error('$%'))
+    assert_equal("`$' without identifiers is not allowed as a global variable name", compile_error('$'))
   end
 end if ripper_test

test/ruby/test_parse.rb

@@ -375,6 +375,25 @@ class TestParse < Test::Unit::TestCase
     assert_nothing_raised { eval(':""') }
   end
 
+  def assert_disallowed_variable(type, noname, *invalid)
+    assert_syntax_error(noname, "`#{noname}' without identifiers is not allowed as #{type} variable name")
+    invalid.each do |name|
+      assert_syntax_error(name, "`#{name}' is not allowed as #{type} variable name")
+    end
+  end
+
+  def test_disallowed_instance_variable
+    assert_disallowed_variable("an instance", *%w[@ @1 @.])
+  end
+
+  def test_disallowed_class_variable
+    assert_disallowed_variable("a class", *%w[@@ @@1 @@.])
+  end
+
+  def test_disallowed_gloal_variable
+    assert_disallowed_variable("a global", *%w[$ $%])
+  end
+
   def test_arg2
     o = Object.new