[Bug other/114191] Flags "Warning" and "Target" don't mix well in target.opt files

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114191

--- Comment #4 from rguenther at suse dot de <rguenther at suse dot de> ---
On Mon, 4 Mar 2024, gjl at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114191
> 
> --- Comment #2 from Georg-Johann Lay <gjl at gcc dot gnu.org> ---
> (In reply to Richard Biener from comment #1)
> > Wmisspelled-isr
> > Target C C++ Var(avr_warn_misspelled_isr) Init(1)
> > Warn if the ISR is misspelled, ...
> > 
> > should eventually work?
> 
> With that, the warnings appear as they should, but the option is not
> recognized:
> 
> $ avr-gcc signal.c -S -Wmisspelled-isr
> error: unrecognized command-line option '-Wmisspelled-isr'
> 
> $ avr-gcc signal.c -S -Wno-misspelled-isr
> error: unrecognized command-line option '-Wno-misspelled-isr'
> 
> $ avr-gcc signal.c -S -Werror=misspelled-isr
> error: '-Werror=misspelled-isr': '-Wmisspelled-isr' is not an option that
> controls warnings

Hmm.  This is how some other targets do it, grepping

grep ^W config/*/*.opt

(a bit noisy because of descriptions).

config/gcn/gcn.opt:Wopenacc-dims
config/gcn/gcn.opt:Warn about invalid OpenACC dimensions.
config/i386/mingw.opt:Wpedantic-ms-format
config/i386/mingw.opt:Warn about none ISO msvcrt scanf/printf width 
extensions.

would be not Target but

config/rs6000/darwin.opt:Waltivec-long-deprecated

uses Target (and thus is dysfunctional)

So it seems we're not set up for 'Target' warnings.