Re: Documenting common C/C++ options

[Richard Biener <richard.guenther@gmail.com>]

On Tue, Oct 10, 2023 at 1:13 PM Florian Weimer via Gcc <gcc@gcc.gnu.org> wrote:
>
> * Richard Earnshaw:
>
> > On 10/10/2023 11:46, Richard Earnshaw (lists) via Gcc wrote:
> >> On 10/10/2023 10:47, Florian Weimer via Gcc wrote:
> >>> Currently, -fsigned-char and -funsigned-char are only documented as C
> >>> language options, although they work for C++ as well (and Objective-C
> >>> and Objective-C++, I assume, but I have not tested this).  There does
> >>> not seem to be a place for this kind of options in the manual.
> >>>
> >>> The options -fshort-enums and -fshort-wchar are documented under
> >>> code-generation options, but this seems to be a bit of a stretch because
> >>> (at least for -fshort-wchar), these too seem to be more about front-end
> >>> behavior.
> >>>
> >>> What would be a good way to address this?
> >>>
> >>> Thanks,
> >>> Florian
> >>>
> >>
> >>
> >> All of these are ABI; so where ever it goes, it should be documented
> >> that changing them will potentially cause issues with any
> >> pre-compiled object files having different settings.
>
> > And you can add -f[un]signed-bitfield to that list as well.
>
> There's already a section for those ABI options that are like
> -fshort-enums:
>
> @node Code Gen Options
> @section Options for Code Generation Conventions
>
> Maybe we should move them over there.
>
> But that wasn't really the direction of my question.  I was wondering
> where we should document a future C version of -fpermissive.

Options common to the C family are documented in 'C Dialect Options'
which says

"The following options control the dialect of C (or languages derived
from C, such as C++, Objective-C and Objective-C++) that the compiler
accepts:"

the options usually specify when they do not apply to all of the above
sibling languages (where it's not obvious).

Richard.

> Thanks,
> Florian
>