+ builder.rb: reject multi-char gvar names starting with 0

lib/parser/builders/default.rb

@@ -594,7 +594,13 @@ def ivar(token)
  end
 
  def gvar(token)
- n(:gvar, [ value(token).to_sym ],
+ gvar_name = value(token)
+
+ if gvar_name.start_with?('$0') && gvar_name.length > 2
+ diagnostic :error, :gvar_name, { :name => gvar_name }, loc(token)
+ end
+
+ n(:gvar, [ gvar_name.to_sym ],
  variable_map(token))
  end
 

lib/parser/messages.rb

@@ -72,6 +72,7 @@ module Parser
  :circular_argument_reference => 'circular argument reference %{var_name}',
  :pm_interp_in_var_name => 'symbol literal with interpolation is not allowed',
  :lvar_name => "`%{name}' is not allowed as a local variable name",
+ :gvar_name => '%{name} is not allowed as a global variable name',
  :undefined_lvar => "no such local variable: `%{name}'",
  :duplicate_variable_name => 'duplicate variable name %{name}',
  :duplicate_pattern_key => 'duplicate hash pattern key %{name}',

lib/parser/ruby33.y

@@ -2520,17 +2520,9 @@ regexp_contents: # nothing
 
  string_dend: tSTRING_DEND
 
- string_dvar: tGVAR
+ string_dvar: nonlocal_var
  {
- result = @builder.gvar(val[0])
- }
- | tIVAR
- {
- result = @builder.ivar(val[0])
- }
- | tCVAR
- {
- result = @builder.cvar(val[0])
+ result = @builder.accessible(val[0])
  }
  | backref
 

test/test_parser.rb

@@ -11370,4 +11370,18 @@ def test_ruby_bug_19281
  %q{},
  SINCE_3_3)
  end
+
+ def test_ungettable_gvar
+ assert_diagnoses(
+ [:error, :gvar_name, { :name => '$01234' }],
+ '$01234',
+ '^^^^^^ location',
+ ALL_VERSIONS)
+
+ assert_diagnoses(
+ [:error, :gvar_name, { :name => '$01234' }],
+ '"#$01234"',
+ ' ^^^^^^ location',
+ ALL_VERSIONS)
+ end
 end