Address some of Peter's comments.
Expect how relocation against entry symbols are handled will be particularly contentious.
Couple of diagnostics suggested needs implementation and how the binding is handled needs investigation.

Add missing full stop.

In D139092#4182991, @MaskRay wrote:

Thanks! LGTM from my review. It'd be good to have a review from a domain expert.

I am going to be out for the next 4 weeks, and will likely have little time reading patches. The patch looks good to land when a domain expert thinks it's fine.

Address review comments.

Use emplace_back() and remove explicit make_pair().

Address some review comments I missed.

Address another round of review comments.

Address further review comments.
Consolidate diagnostic tests to a single test file.

Address further review comments.

Address review comments and add more tests.

Add tests for diagnostics emitted during sanity checking the cmse import library

Thanks for the design docs. At a high-level this gives a good summary on what you intend the multilib feature to do. Couple of suggestions.

Added

• Better help text
• The workflow step of linking a cmse non-secure app against a cmse import library
• Sanity checking of the cmse import library

LGTM.

Addressing a review comment I missed.

Fix review comments.
arm-cmse-invalid-arch.s only works for the ARM target.

Now I can do arc patch D139092
Rebasing using arc diff $(git merge-base HEAD origin) --update D139092

arc patch D139092 still gives me the error.

arc patch D139092 fails with the following error.

Thanks for the comprehensive reviews.

LGTM.

LGTM.

[clang][ARM] Re-word PACBTI warning.

LGTM.

LGTM.

The CI errors seem unrelated.

Fix clang-format errors.

Rebase.

Add new interface isArmMClass() to the Triple class.
Use isArmT32() and isArmMClass() to emit PACBTI warnings for ARM.

Refactor the check conditions to a single function (isArmT32)

Fix clang-format errors.

Address review comments.

Rebase

Address review comment.

[lld][ELF] remove empty SyntheticSections from inputSections

Fix clang-tidy errors

Rebase attempt 2

Rebase

Address review comments

Ping?

Commited the fix to LLVM Release 12.x branch. Rendering looks okay this time.

Sorry for the back-and-forth. Requesting re-review.

Add a newline before the sub-list to fix a rendering issue.

Reopening to add a missing empty line before starting the level-2 list.

Commited to LLVM Release 12.x branch

Abandoning this revision because I think I messed up something when using arcanist to fix pre-merge errors.
https://buildkite.com/llvm-project/diff-checks/builds/32719
I'll submit a new review.

• Fix test failures after a92ceea91116e7b95d23eff634507fa2cff86ef2
• [libc++] Fix extern template test failing on Windows
• [libc++] Fix extern-templates.sh.cpp test on Linux
• [release][docs] List all cores Arm has added support for in LLVM 12.