Re: maint.mk sc_prohibit_always-defined_macros complains about build-aux/warn-on-use.h

[Jim Meyering]

Martin von Gagern wrote:

> Hi there!
>
> I've got gnulib in my repository, so devs don't need a git checkout.
> When I last ran the syntax checks from maint.mk, I got a false positive
> from prohibit_always-defined_macros complaining about the definition of
> environ in build-aux/warn-on-use.h.
>
> The error is due to the following line in warn-on-use.h
>    # define environ (*rpl_environ ())
> which conflicts with definitions from unistd.in.h.
>
> Maybe you should alter that file so it doesn't match the rule. Or you
> should explicitely exclude it from the list of files to check.
>
> In my package, wdiff, I've excluded the whole build-aux directory from
> that check, but I can easily do so without creating extra files due to
> my personal modifications to gnulib.
> http://github.com/gagern/gnulib/commit/57646d674f68676ca3b9
> I guess I should try to get my gnulib copyright assignment forms
> completed so you can include this upstream as well...

Hi Martin,

Thanks for the report.
You can disable that check in a several of ways:
  - add its name to the list of checks to skip in cfg.mk:

      local-checks-to-skip += sc_prohibit_always-defined_macros

  - define gnulib_dir to a name that is not a directory
  - create an .x-sc_prohibit_always-defined_macros file containing
      regexps matching the names of any files you want to exempt

Considering that you version-control parts of gnulib in your
primary repository, disabling the test might be best, since
I would expect many false positives with such usage.
The regexps to search for are derived from gnulib's lib/ directory.
If the same lib/* files are also searched for definitions (because
you've chosen to version control them), every one of those regular
expressions will get at least one false positive: for its definition
in gnulib.