Re: [PATCH][v2] Always default to DWARF2_DEBUG if not specified, warn about deprecated STABS

[Jeff Law <jeffreyalaw@gmail.com>]

On 9/13/2021 1:31 AM, Richard Biener wrote:
> This makes defaults.h choose DWARF2_DEBUG if PREFERRED_DEBUGGING_TYPE
> is not specified by the target and NO_DEBUG if DWARF is not supported.
>
> It also makes us warn when STABS is enabled and removes the corresponding
> diagnostic from the Ada frontend.  The warnings are pruned from the
> testsuite output via prune_gcc_output.
>
> This leaves the following targets without debug support:
>
>   pdp11-*-*   pdp11 is a.out, dwarf support is difficult
>   m68k*-*-openbsd*  it looks like this is a.out as well, at least it does
>                     not pretend to support DWARF
>   hppa[12]*-*-hpux10*  does seem to not support DWARF
I would probably argue that hpux10 should just be removed, along with 
hpux 7-9 if they haven't been already.  It's the epitome of a dead platform.


>   vax-*-openbsd*  seems to be a.out as well, does not support DWARF
>
> behavior will be like
>
>> ./cc1 -quiet t.c -g
> cc1: warning: target system does not support debug output
>> ./cc1 -quiet t.c -gstabs
> t.c: warning: STABS debugging information is obsolete and not supported anymore
>
> that is, -g is unsupported but -gstabs will generate STABS (the above
> is for pdp11).  It would be nice if maintainers could confirm the above
> listed configurations do not support DWARF and weight in whether to
> (apart from pdp11) the specific configurations can be obsoleted or
> adjusted.  It looks like we do not have any openbsd maintainer.
> I've discussed the situation for pdp11 with Paul already at some point
> but we didn't reach any conclusion besides that it would be nice to
> move pdp11 to ELF.
>
>
> 2021-09-10  Richard Biener  <rguenther@suse.de>
>
> gcc/
> 	* defaults.h (PREFERRED_DEBUGGING_TYPE): Choose DWARF2_DEBUG
> 	or NO_DEBUG.
> 	* toplev.c (process_options): Warn when STABS debugging is
> 	enabled.
>
> gcc/ada/
> 	* gcc-interface/misc.c (gnat_post_options): Do not warn
> 	about DBX_DEBUG use here.
>
> gcc/testsuite/
> 	* lib/prune.exp: Prune STABS obsoletion message.
OK
jeff