ReleaseNotes: add lld/ELF notes

[MaskRay]

No description provided.

[llvmbot]

@llvm/pr-subscribers-lld

Author: Fangrui Song (MaskRay)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/80393.diff

1 Files Affected:

• (modified) lld/docs/ReleaseNotes.rst (+34)

diff --git a/lld/docs/ReleaseNotes.rst b/lld/docs/ReleaseNotes.rst
index 01669543cd50c..824cc6f56f8d5 100644
--- a/lld/docs/ReleaseNotes.rst
+++ b/lld/docs/ReleaseNotes.rst
@@ -29,8 +29,42 @@ ELF Improvements
 * ``--fat-lto-objects`` option is added to support LLVM FatLTO.
   Without ``--fat-lto-objects``, LLD will link LLVM FatLTO objects using the
   relocatable object file. (`D146778 <https://reviews.llvm.org/D146778>`_)
+* ``-Bsymbolic-non-weak`` is added to directly bind non-weak definitions.
+  (`D158322 <https://reviews.llvm.org/D158322>`_)
+* ``--lto-validate-all-vtables-have-type-infos``, which complements
+  ``--lto-whole-program-visibility``, is added to disable unsafe whole-program
+  devirtualization. ``--lto-known-safe-vtables=<glob>`` can be used
+  to mark known-safe vtable symbols.
+  (`D155659 <https://reviews.llvm.org/D155659>`_)
+* ``--no-allow-shlib-undefined`` now reports errors for DSO referencing
+  non-exported definitions.
+  (`#70769 <https://github.com/llvm/llvm-project/pull/70769>`_)
 * common-page-size can now be larger than the system page-size.
   (`#57618 <https://github.com/llvm/llvm-project/issues/57618>`_)
+* When call graph profile information is availablue due to instrumentation or
+  sample PGO, input sections are now sorted using the new ``cdsort`` algorithm,
+  better than the previous ``hfsort`` algorithm.
+  (`D152840 <https://reviews.llvm.org/D152840>`_)
+* Symbol assignments like ``a = DEFINED(a) ? a : 0;`` are now handled.
+  (`#65866 <https://github.com/llvm/llvm-project/pull/65866>`_)
+* ``OVERLAY`` now supports optional start address and LMA
+  (`#77272 <https://github.com/llvm/llvm-project/pull/77272>`_)
+* Relocations referencing a symbol defined in ``/DISCARD/`` section now lead to
+  an error.
+  (`#69295 <https://github.com/llvm/llvm-project/pull/69295>`_)
+* For AArch64 MTE, global variable descriptors have been implemented.
+  (`D152921 <https://reviews.llvm.org/D152921>`_)
+* ``R_LARCH_PCREL20_S2``/``R_LARCH_ADD6``/``R_LARCH_CALL36`` and extreme code
+  model relocations are now supported.
+* ``--emit-relocs`` is now supported for RISC-V linker relaxation.
+  (`D159082 <https://reviews.llvm.org/D159082>`_)
+* Call relaxation respects RVC when mixing +c and -c relocatable files.
+  (`#73977 <https://github.com/llvm/llvm-project/pull/73977>`_)
+* ``R_RISCV_SET_ULEB128``/``R_RISCV_SUB_ULEB128`` relocations are now supported.
+  (`#72610 <https://github.com/llvm/llvm-project/pull/72610>`_)
+  (`#77261 <https://github.com/llvm/llvm-project/pull/77261>`_)
+* RISC-V TLSDESC is now supported.
+  (`#79239 <https://github.com/llvm/llvm-project/pull/79239>`_)
 
 Breaking changes
 ----------------

[MaskRay]

"""
Merging is blocked
The base branch does not allow updates. Learn more about protected branches.
"""

Once this is approved, @tstellar I think I'll notify you to merge this into release/18.x?
Perhaps you can edit https://discourse.llvm.org/t/release-18-x-branch-has-been-created/76480/4 to tell us what to do :) Probably give an example PR.

[arichardson]

Lgtm

[smithp35]

What's there LGTM too, I've suggested a couple of possible additions that you might want to consider.

[smithp35]

Could be worth adding

* R_AARCH64_GOTPCREL32 is now supported. (`#72584 <https://github.com/llvm/llvm-project/pull/72584>`_)

[smeenai]

Good call, as well as R_RISCV_GOT32_PCREL (#72587)

[MaskRay]

Thanks for the addition. Added both.

[smithp35]

Could be worth adding

* ``--save-temps --lto-emit-asm`` now derives ELF/asm file names from bitcode file names. ld.lld --save-temps a.o d/b.o -o out` will create ELF relocatable files `out.lto.a.o`/`d/out.lto.b.o` instead of `out1.lto.o`/`out2.lto.o`. (`#78835 <https://github.com/llvm/llvm-project/pull/78835>`_)

[MaskRay]

Thanks for the suggestion! I noticed this and GOT32_PCREL and was wondering whether they are minor. But your mentioning this made it clear it is worth mentioning:)

This entry may motivate wasm and Mach-O folks to implement a similar change.
(I am actually self motivated to do this if I have some spare time)

[smeenai]

LGTM, thanks!

[smeenai]

Good call, as well as R_RISCV_GOT32_PCREL (#72587)

[MaskRay]

@tstellar This should be in a good shape to be merged:) Thanks