Bug #13809: Unused variable warning does not occur when a method with the same name was called

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.4.1p111 (2017-03-22 revision 58053) [x86_64-linux]
• Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN

[pocke (Masataka Kuwabara)]

problem

a = 1
a()

a is unused, but ruby -cw does not add warning for this code.

$ ruby -cw test.rb
Syntax OK

Cause

The parser changes mode by lvar definition. At that time, parser checks whether lvar is defined that is with same name.
https://github.com/ruby/ruby/blob/6ee82564fac2745e45154938b5b75d9f5ab70b58/parse.y#L7886
Then, if lvar with same name is defined, the lvar is marked as used.
https://github.com/ruby/ruby/blob/6ee82564fac2745e45154938b5b75d9f5ab70b58/parse.y#L10494

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset trunk|r59585.

---

parse.y: set used flag in gettable

• parse.y (dvar_defined_ref, dvar_defined): rename macros. only
  gettable uses the former. assignable should not set LVAR_USED
  flag.

• parse.y (gettable_gen): set used flag on local/dynamic variables
  instead of setting in lexer. [ruby-core:82368] [Bug #13809]