On Tue, Dec 13, 2022 at 09:50:23AM +0000, Jonathan Wakely via Gcc-patches wrote:
> On Tue, 13 Dec 2022 at 09:44, Jakub Jelinek <ja...@redhat.com> wrote:
> >
> > Hi!
> >
> > When writing the r13-4629 commit log I've realized that libsanitizer
> > isn't the only place which nowadays renames libbacktrace symbols,
> > libstdc++ does that too.
> >
> > Ok for trunk if this passes bootstrap/regtest?
>
> OK, thanks.
>
> When we move the backtrace symbols from libstdc++_libbacktrace.a into
> libstdc++.so we probably want to look into removing the symbols we
> don't actually use. Renaming them to our private namespace is good,
> but not including them in the library at all would be better.
Most of them I assume are actually used, the reason they aren't static
is that libbacktrace contains multiple TUs and some APIs are used to
interface between the TUs. __attribute__((visibility ("hidden"))) would
work for shared libraries and targets where it actually works, but
we still have the *.a libraries where such symbols are visible, so I think
some renaming is needed.
Though, my understanding of backtrace_uncompress_{lzma,zdebug,zstd} is that
those are there just as small wrappers for make check purposes only,
so I bet those symbols could be easily removed (say by not defining them
at all if their names are macros, then we could keep them in
backtrace-rename.h as is).
> > 2022-12-13 Jakub Jelinek <ja...@redhat.com>
> >
> > * src/libbacktrace/backtrace-rename.h (backtrace_uncompress_zstd):
> > Define.
> >
> > --- libstdc++-v3/src/libbacktrace/backtrace-rename.h.jj 2022-09-01
> > 09:37:58.452624676 +0200
> > +++ libstdc++-v3/src/libbacktrace/backtrace-rename.h 2022-12-13
> > 10:41:14.551699599 +0100
> > @@ -16,6 +16,7 @@
> > #define backtrace_syminfo __glibcxx_backtrace_syminfo
> > #define backtrace_uncompress_lzma __glibcxx_backtrace_uncompress_lzma
> > #define backtrace_uncompress_zdebug __glibcxx_backtrace_uncompress_zdebug
> > +#define backtrace_uncompress_zstd __glibcxx_backtrace_uncompress_zstd
> > #define backtrace_vector_finish __glibcxx_backtrace_vector_finish
> > #define backtrace_vector_grow __glibcxx_backtrace_vector_grow
> > #define backtrace_vector_release __glibcxx_backtrace_vector_release
Jakub
