https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123259
Bug ID: 123259
Summary: Allow more control over CTF generation
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: ro at gcc dot gnu.org
CC: david.faust at oracle dot com, ibhagat at gcc dot gnu.org
Target Milestone: ---
I've recently been working on a patch to support Solaris CTF, which proved easy
due to Ali Bahrami's work. It can be done just in specs. I've introduce a new
-gsctf, which doesn't do more than pass -gctf for compilation and -z ctf when
linking.
To put this through its paces, I tried a full GCC bootstrap with -gsctf added
via a boot config file. It only sets STAGE[23]_[CT]FLAGS to -gsctf. While
this
worked mostly fine, I ran into an issue that also affects GNU CTF:
For all non-C languages, I get warnings like
cc1plus: note: CTF debug info requested, but not supported for ‘GNU C++17’
frontend
This happens because CFLAGS is often passed for non-C languages, with no way
to restrict it.
While that warning is perfectly benign, it has unfortunate consequences on the
bootstrap and test run: libstdc++ testing is utterly confused by that warning,
leading to tons of failures.
I believe this issue extends to all mixed-language projects, not just GCC, so
it may warrant a general solution. For the time being, I've restricted passing
-gctf in the specs like
%{,c:%{gsctf:-gctf}}
i.e. silently ignoring -gsctf for non-C compilations. While this works (except
for Ada), doing this behind the user's back isn't optimal.
I can thing of two solutions:
* Introduce -Wctf (on by default), so one could suppress the warning with
-Wno-ctf.
* Alternatively (or in addition), one could provide more flexibility by
allowing -gctf more control over which languages it applies to, something
like
-gctf[=[c,supported,all]
This may well be overkill and the issue considered build-system only.
Thoughts?
