---
- branch: MAIN
  date: Wed Mar 20 13:50:37 UTC 2024
  files:
  - new: '1.395'
    old: '1.394'
    path: src/share/mk/bsd.lib.mk
    pathrev: src/share/mk/bsd.lib.mk@1.395
    type: modified
  id: 20240320T135037Z.0e2d7f60ed66cad33d8752c0f6e7858230095b1d
  log: |
    bsd.lib.mk: Check expected vs actual symbols at build-time.

    If, for LIB=foo, you create a file foo.expsym, bsd.lib.mk will list
    the dynamic symbols and their versions with

    nm --dynamic --extern-only --defined-only --with-symbol-versions

    and compare the names (not addresses or types) to foo.expsym.  If
    there are any differences, they will be printed and the build will
    fail.

    foo.expsym should be sorted with `LANG=C sort -u'.

    This way, you can verify changes don't inadvertently add or remove
    symbols.  If you do want to add (or, if you're bumping the major,
    remove) symbols, you can verify the changes and edit the foo.expsym
    file accordingly.  This will also help to enforce rules about symbol
    changes on pullups in release branches.

    Note that using a version map (-Wl,--version-script=...) doesn't
    catch symbol removal -- ld quietly ignores symbols in the version map
    that aren't actually defined by any object in the library.  So this
    supplements the version map.

    Proposed on tech-userlevel:
    https://mail-index.NetBSD.org/tech-userlevel/2024/03/16/msg014264.html
  module: src
  subject: 'CVS commit: src/share/mk'
  unixtime: '1710942637'
  user: riastradh