pending patches

[Mark Wielaard]

Hi Ulf,

Here are some short comments on the pending patches that I would like to
deal with after the 0.169 release. I believe what we have now on master
is a good set of fixes that look OK on Fedora 25/RHEL7 x86_64. I'll run
some tests on other distros and supported Fedora/RHEL architectures in
the next days. And if no show-stoppers pop up I'll like to do a release
on Friday. Then next week we return to these patches.

- Add gnulub modules to replace missing libc functionality.
  The big one. I am surprised that actually made it to the list.
  I haven't tried it out yet, but it looks basically sane.
  What is missing is a description/script to run for updates.
  I have to add something like that for some other special files
  (elf.h, po files) too so anybody can easily run it before a
  release.

- Drop handrolled or #ifdef'ed libc replacement.
  Right, should go in right after the above.

- Check for -z,defs, -z,relro, -fPIC, -fPIE before using them
  There are actually two versions, I haven't looked yet how they differ.
- Check if gcc complains about __attribute__ (visibility(..))
- Disable symbol versioning if .symver doesn't work
- Check if rpath is supported before setting it

In all of the above cases checking for support is a good thing.
But I am a little hesitant about automatically disabling support.
For example our binary compatibility depends on having symbol versioning
support. It seems bad to "silently" break that. And without rpath
support backends aren't found and stuff will mysteriously break. So I
think I prefer configure to error out and have an explicit override
option someone would have to use indicating they are building a broken
elfutils.

- Check if we need -lintl for linking gettext
  This looks OK, but I don't know much about gettext support.

- Generalize library names
  This looks like a nice cleanup, but I don't know anything about how
  non-gnu/linux systems do library sonames (I also use a local hack
  sometimes to explicitly set a different version that I should upstream
  myself).

- Check native binary format
  Yes, running self-test/checks on non-ELF binaries is not going to
  work.

Cheers,

Mark