tree eb677115052bb0adcacdc383b0587006fbfda505
parent eb2c9e46fd03c2a4bd0b8aa2c273e0d99f93623b
author Ulrich Weigand <ulrich.weigand@de.ibm.com> 1707820161 +0100
committer Copybara-Service <copybara-worker@google.com> 1707820517 -0800

[lld] Add target support for SystemZ (s390x) (#75643)

This patch adds full support for linking SystemZ (ELF s390x) object
files. Support should be generally complete:
- All relocation types are supported.
- Full shared library support (DYNAMIC, GOT, PLT, ifunc).
- Relaxation of TLS and GOT relocations where appropriate.
- Platform-specific test cases.

In addition to new platform code and the obvious changes, there were a
few additional changes to common code:

- Add three new RelExpr members (R_GOTPLT_OFF, R_GOTPLT_PC, and
R_PLT_GOTREL) needed to support certain s390x relocations. I chose not
to use a platform-specific name since nothing in the definition of these
relocs is actually platform-specific; it is well possible that other
platforms will need the same.

- A couple of tweaks to TLS relocation handling, as the particular
semantics of the s390x versions differ slightly. See comments in the
code.

This was tested by building and testing >1500 Fedora packages, with only
a handful of failures; as these also have issues when building with LLD
on other architectures, they seem unrelated.

Co-authored-by: Tulio Magno Quites Machado Filho <tuliom@redhat.com>
GitOrigin-RevId: fe3406e349884e4ef61480dd0607f1e237102c74