Re: CGI::Appl can't find sub

I have determined the cause of the problem. Here are more details to the calls made for the problem seen when adding a new call in AA.pm to BB.pm.

AA.pm
use strict
use warning

  sub Abug1 {}
  sub Asub2 {
      BB::Bsub1(1,2,3);
      BB::Bsub2(hostname);  # hostname is a "bareword"
}
  sub Asub3 {}
[download]

Asub2() is only invoked at runtime via CGI::Applicaton run_modes(). The problem is that with "strict" enabled, barewords are not allowed as parameters to subroutine calls. Instead of reporting an error, the compilation is quietly aborted in the *next* subroutine when a single quote is found: resulting in all subsequent subroutines not being compiled. It also results in the program running for code that compiled and the offending subroutine working just fine. I could see that the other subroutines were missing in the debugger, I just couldn't figure out why. The key was running:

perl -MO=Terse AA.pm

It reports the offending line and where compilation is terminated. I'm glad I ignored the module description I found on perl.org:

"This module is useful for people who are writing their own back end, or who are learning about the Perl internals. It's not useful to the average programmer."

I expect that this is an unusual case because:

1. The resolution of the function doesn't occur until the specific web page is selected and is done as a string lookup.

2. The invocation of the subroutine is protected in "eval { }" so the program keeps on running.

Thanks for the input and I hope this can help someone in the future.

Comment on Re: CGI::Appl can't find sub Download Code

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Re^2: CGI::Appl can't find sub by Anonymous Monk on Jun 14, 2014 at 01:05 UTC
The problem is that with "strict" enabled, barewords are not allowed as parameters to subroutine calls Instead of reporting an error, the compilation is quietly aborted in the next subroutine when a single quote is found barewords don't have that effect, they're not magic	[reply]
Re^3: CGI::Appl can't find sub by jimt999 (Initiate) on Jun 14, 2014 at 03:16 UTC
Okay, then please explain the output from the "perl -MO=Terse AA.pm", which is: Bareword "CA_list" not allowed while "strict subs" in use at AA.pm line 309. BEGIN not safe after errors--compilation aborted at AA.pm line 423. Note that line 423 is about 15 lines into the next subroutine after the one with the bareword parameter. Adding double quotes to the parameter fixed the problem. What made this so hard to root cause is that the problem did not cause the subroutine with the problem to fail. The error message also corresponds with what was observable in the perl debugger - "S AA" failed to show any subroutines after the one that contained line #309.	[reply]
Re^4: CGI::Appl can't find sub by Anonymous Monk on Jun 14, 2014 at 09:31 UTC
Okay, then please explain the output from the "perl -MO=Terse AA.pm", which is ... Ask yourself , why am I using barewords? If they're not function/package names, or hash keys, then they shouldn't be barewords If your barewords are strings, you should quote your strings perlintro, Basic debugging checklist and brian's Guide to Solving Any Perl Problem If this code you posted in Re: CGI::Appl can't find sub is any indication it means perintro was skipped `$ perl -c aa.pm syntax error at aa.pm line 4, near "use strict use warning " syntax error at aa.pm line 8, near "}" aa.pm had compilation errors.` [download] Tracking down syntax errors is very easy, its `perl -c everyfile.pl perl -c lib/Everyfile.pm ...` [download] When you're developing , skip B::Terse, don't forget to test every single subroutine in you write in your test suite, so even if eval is hiding any die-ing you'll notice when you typo Hi :)	[reply] [d/l] [select]