Re: Profiled libraries on freebsd-current

From: Steve Kargl <sgk_at_troutmask.apl.washington.edu>
Date: Fri, 29 Apr 2022 20:12:57 UTC 
On Fri, Apr 29, 2022 at 12:51:12PM -0700, Mark Millard wrote:
> On 2022-Apr-29, at 12:38, Mark Millard <marklmi@yahoo.com> wrote:
> 
> > https://cgit.freebsd.org/src/commit/?id=175841285e289edebb6603da39f02549521ce950
> > says the following (later), but first I quote the part tbat dirves the
> > interpretation:
> > 
> > QUOTE
> > Clang's -pg support and mcount() remain, so building with -pg can still
> > be used on code that the user builds; we just do not provide prebuilt
> > libraries compiled with -pg.
> > END QUOTE
> > 
> > No WITH_PROFILE options means no "prebuilt libraries compiled with -pg".
> > 
> > 
> > The overall notice was:
> > 
> > author	Ed Maste <emaste@FreeBSD.org>	2021-06-27 17:21:26 +0000
> > committer	Ed Maste <emaste@FreeBSD.org>	2021-06-28 15:36:59 +0000
> > commit	175841285e289edebb6603da39f02549521ce950 (patch)
> > tree	9c2d3b05546961457bb18faeebd2302a25559b49
> > parent	243b95978debac3db06df6d26ca9f8d84f6cbd83 (diff)
> > download	src-175841285e289edebb6603da39f02549521ce950.tar.gz
> > src-175841285e289edebb6603da39f02549521ce950.zip
> > 
> > Add deprecation notice for WITH_PROFILE option
> > 
> > As discussed on freebsd-current [1] and freebsd-arch [2] and review
> > D30833, FreeBSD 14 will ship without the _p.a libraries built with -pg.
> > Both upstream and base system (in commit b762974cf4b9) Clang have been
> > modified to remove the special case for linking against these libraries.
> > 
> > Clang's -pg support and mcount() remain, so building with -pg can still
> > be used on code that the user builds; we just do not provide prebuilt
> > libraries compiled with -pg.  A similar change is still needed for GCC.
> > 
> > [1]  
> > https://lists.freebsd.org/pipermail/freebsd-current/2020-January/075105.html
> > 
> > [2] 
> > https://lists.freebsd.org/archives/freebsd-arch/2021-June/000016.html
> > 
> > 
> > MFC after:	1 week
> > Sponsored by:	The FreeBSD Foundation
> > END QUOTE
> > 
> 
> I probably should have been explicit: the actual removal of WITH_PROFILE
> has not happened yet. So testing attempts to use it are not yet expected
> to have the new behavior yet.
> 

The evenual absence of libc_p.a and libm_p.a will break GCC's
-pg option in GCC.  One will then need to know how to change the
GCC source or install symlinks for to point *_p.a a the *.a libs.

-- 
Steve