detecting when an option is not available

[Ian Lance Taylor]

Andreas Schwab <schwab@linux-m68k.org> writes:

> Ian Lance Taylor <iant@google.com> writes:
>
>> The trick to find out if a -Wno- option is supported is to force a
>> compiler error.  E.g.,
>
> The trick to find out if a -Wno- option is supported is to check if the
> positive form is accepted.  See ACX_PROG_CC_WARNING_OPTS.

That does seems simpler.  Thanks.

Ian