Feature #7730: Top level variables aren't checked for assigned but unused behavior

• Status: Closed
• Priority: Normal
• Assignee: nobu (Nobuyoshi Nakada)
• Target version: 2.6

[agrimm (Andrew Grimm)]

In the following code, variable a in the method gets a warning, but variable b in top level code doesn't get any warning

def warning_method
  a = 2
end

b = 2
warning_method

$ ruby -w no_toplevel_warnings.rb 
no_toplevel_warnings.rb:2: warning: assigned but unused variable - a

It is possible to detect that b is unused if the script is required from another script.

I'd like Ruby to be able to detect that b is an assigned but unused variable.

[nobu (Nobuyoshi Nakada)]

• File 0001-parse.y-warn-assigned-but-unused-in-toplevel.patch 0001-parse.y-warn-assigned-but-unused-in-toplevel.patch added

Agree except for -e option.

[ko1 (Koichi Sasada)]

• Category set to core
• Assignee set to nobu (Nobuyoshi Nakada)
• Target version set to 2.6

Nobu, do you need matz's approval?

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r38982.
Andrew, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

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parse.y: warn assigned but unused in toplevel

• parse.y (local_push_gen): warn assigned but unused variables also in
  toplevel, except for -e option. [Feature #7730] [ruby-core:51580]