Re: warning: module to simplify adding compiler warnings

[Bruno Haible]

Simon Josefsson wrote:
> >> FWIW, I wouldn't use AC_ARG_VAR for gl_WARN_INIT.
> >
> > Yes, agreed: When the user wants to disable some warnings, he can do so by
> > putting the opposite -W options into the CFLAGS when configuring. That's
> > what my proposed piece of documentation says. Non-maintainers don't need
> > to set different warning options on different subdirectories of the package.
> 
> Wouldn't this make it impossible to set WARN_CFLAGS=-Werror when
> invoking configure?

No. Citing the autoconf documentation:
  "AC_ARG_VAR (VARIABLE, DESCRIPTION)
     Declare VARIABLE is a precious variable, and include its
     DESCRIPTION in the variable section of `./configure --help'.
     Being precious means that ..."
etc. - Just keep WARN_CFLAGS uninitialized in the configure script, and
you can give it an initial value from the environment variable.

> Or at least make that usage undocumented.
> 
> The original motivation for the module was that -Werror cannot go into
> CFLAGS, so I need to provide the flag somewhere else, which ended up
> being WARN_CFLAGS.  If that variable isn't documented ...

You write the documentation. I provided only a sketch of it.

Bruno