Re: Turn on compiler warnings by default for AC_PROG_CC, AC_PROG_CXX & AC_PROG_FC

On Tue, 14 Jan 2014 10:53:05 -0500, Dale Visser <[email protected]> wrote:
> One advantage of AC_FLAGS_WARN_ALL is that it has been written to work not
> only with gcc, but also with other compilers, such as clang and icc.

I think that's an awesome part of this approach.

> Also, it is possible to easily add flags in configure.ac using the provided
> AC_APPEND_FLAGS macro. For example, to specifically disable some warnings
> applicable to comment text:
> 
> AC_APPEND_FLAG([-Wno-comment], [CFLAGS])

I earlier replied to Dale Visser about this, but didn't reply to the whole list (sorry about that).

The AC_APPEND_FLAG doesn't provide the functionality I would want for portability,
because it doesn't really check if the flag works (and it doesn't report the checking either).
For example, if I add this:
AC_APPEND_FLAG([-Wno-such-option], [CFLAGS])
the "-Wno-such-option" is still passed to the compiler. Ugh.

Perhaps you could change its functionality, or create a separate macro with that functionality.
That way, you could enable/disable warnings on compilers that accepted the flag... and
still work on compilers that didn't support it.

Anyway, I think you're on the right path, just need some tweaks before it's ready.

--- David A. Wheeler