Bug #20681: Regular expression warnings are treated as compiler warnings during runtime

• Status: Feedback
• Assignee: -
• Target version: -
• ruby -v: 3.3.4
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[Earlopain (Earlopain _)]

I have some code that recieves arbitrary input and parses it as a regexp. To supress potential warnings I'm defining the warn method. Unfortunately it is not getting called:

def warn(...)
  puts "CALLED"
end

source = "/\w**/"
Regexp.new(source)

Running this emits a warning and doesn't print "CALLED":

$ ruby test.rb
test.rb:6: warning: regular expression has redundant nested repeat operator '*': /\/w**\//

I looked a bit at the code and found something which I think is supposed to handle this case but it seems like its not checking against the right thing: https://github.com/ruby/ruby/blob/4dbf386ca248df0f47f31dc28cdeabe8d4477e5b/regparse.c#L2986-L2994

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Feedback

You may want to re-define Warning.warn.

[Earlopain (Earlopain _)]

nobu (Nobuyoshi Nakada) wrote in #note-1:

You may want to re-define Warning.warn.

Thank you, that works. Apologies for the wrong report.