CVS commit: src/external/bsd/libarchive/lib/libarchive

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Thu Nov 21 18:17:40 UTC 2024

Modified Files:
        src/external/bsd/libarchive/lib/libarchive: Makefile

Log Message:
libarchive: Export only public symbols.

1. Build with -fvisibility=hidden -D__LIBARCHIVE_ENABLE_VISIBILITY,
   which is upstream's supported way to export only public symbols.

   => Verified that this only suppresses symbols which are _not_
      declared in libarchive's public header files.

2. Link with -Wl,--exclude-libs,libzstd so that statically linked
   libzstd symbols aren't exported.

   => Verified that this only suppresses libzstd symbols which are not
      part of libarchive at all.

This deletes exported symbols from a shared library -- but only those
that should never have been exported to begin with, and that can't be
used by normal libarchive applications without going out of their way
to get at internal symbols.  In fact, some of these symbols, like
blake2s_init, are likely to collide with other libraries or
applications.

So while this technically violates the letter of shlib major rules
and releng pullup rules by deleting exported symbols, I'm not bumping
and I intend to pull this up to 10 (and maybe 9) -- because I suspect
it is more likely that libarchive's private symbols will conflict
with other uses in real applications than that real applications will
rely on libarchive's private symbols.

PR lib/58829: libarchive exports excess symbols


To generate a diff of this commit:
cvs rdiff -u -r1.19 -r1.20 \
    src/external/bsd/libarchive/lib/libarchive/Makefile

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.