Skip to content

llvmPackages_{20,21,git}.compiler-rt: no fmv on aarch64 without libc#409265

Merged
RossComputerGuy merged 1 commit intoNixOS:stagingfrom
RossComputerGuy:fix/pkgsllvm/stdenv
Sep 13, 2025
Merged

llvmPackages_{20,21,git}.compiler-rt: no fmv on aarch64 without libc#409265
RossComputerGuy merged 1 commit intoNixOS:stagingfrom
RossComputerGuy:fix/pkgsllvm/stdenv

Conversation

@RossComputerGuy
Copy link
Member

@RossComputerGuy RossComputerGuy commented May 21, 2025

…patch

Things done

Fixes #393603
Reverts #380213
Required for #407738

We're sending this patch to master and backporting it so pkgsLLVM actually works correctly with LLVM 20 and git.

  • Built on platform(s)
    • x86_64-linux
    • aarch64-linux
    • x86_64-darwin
    • aarch64-darwin
  • For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
    • sandbox = relaxed
    • sandbox = true
  • Tested, as applicable:
  • Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
  • Tested basic functionality of all binary files (usually in ./result/bin/)
  • Nixpkgs 25.11 Release Notes (or backporting 24.11 and 25.05 Nixpkgs Release notes)
    • (Package updates) Added a release notes entry if the change is major or breaking
  • NixOS 25.11 Release Notes (or backporting 24.11 and 25.05 NixOS Release notes)
    • (Module updates) Added a release notes entry if the change is significant
    • (Module addition) Added a release notes entry if adding a new NixOS module
  • Fits CONTRIBUTING.md.

Add a 👍 reaction to pull requests you find important.

@github-actions github-actions bot added the 6.topic: llvm/clang Issues related to llvmPackages, clangStdenv and related label May 21, 2025
@github-actions github-actions bot added 10.rebuild-darwin: 11-100 This PR causes between 11 and 100 packages to rebuild on Darwin. 10.rebuild-linux: 11-100 This PR causes between 11 and 100 packages to rebuild on Linux. 11.by: package-maintainer This PR was created by a maintainer of all the package it changes. labels May 21, 2025
@RossComputerGuy RossComputerGuy mentioned this pull request May 21, 2025
Merged
13 tasks
@alyssais
Copy link
Member

alyssais commented May 25, 2025

Upstream?

@RossComputerGuy
Copy link
Member Author

RossComputerGuy commented May 25, 2025

Already tried going upstream but the PR was closed llvm/llvm-project#125922

@alyssais
Copy link
Member

alyssais commented May 25, 2025

Hmm, unfortunate…

@Ericson2314 what do you think about applying this? Seems a real shame to be adding a new LLVM patch.

@peterwaller-arm
Copy link
Contributor

peterwaller-arm commented Jul 15, 2025 •
edited
Loading

@Ericson2314 just published a blog post adjacent to this: https://blog.obsidian.systems/compiler-bootstrapping-in-nixpkgs/

As patch author, my opinion is that given the timescales involved for a proper fix (e.g. llvm/llvm-project#127227), it would be good to unbreak this today in nixpkgs.

@RossComputerGuy
Copy link
Member Author

RossComputerGuy commented Jul 15, 2025

timescales involved for a proper fix (e.g. #127227)

Wrong issue linked?

@peterwaller-arm
Copy link
Contributor

peterwaller-arm commented Jul 15, 2025

Wrong issue linked?

Right issue number, wrong repo. Fixed.

@Artturin Artturin closed this Jul 28, 2025
@Artturin Artturin reopened this Jul 28, 2025
@nixpkgs-ci nixpkgs-ci bot added 10.rebuild-linux: 101-500 This PR causes between 101 and 500 packages to rebuild on Linux. and removed 10.rebuild-linux: 11-100 This PR causes between 11 and 100 packages to rebuild on Linux. labels Jul 28, 2025
@Ericson2314
Copy link
Member

Ericson2314 commented Jul 29, 2025

Can we make the patch less linux-specific? Conceptually, we're talking about about generally building a "freestanding" compiler-rt on a non-freestanding platform, of which Linux is merely one example.

@peterwaller-arm
Copy link
Contributor

peterwaller-arm commented Jul 29, 2025

Can we make the patch less linux-specific? Conceptually, we're talking about about generally building a "freestanding" compiler-rt on a non-freestanding platform, of which Linux is merely one example.

https://github.com/llvm/llvm-project/blob/0c0aa56cdcf1fe3970a5f3875db412530512fc07/compiler-rt/lib/builtins/CMakeLists.txt#L884

It looks like setting COMPILER_RT_DISABLE_AARCH64_FMV is a better non-linux specific way forward here.

@RossComputerGuy RossComputerGuy mentioned this pull request Jul 31, 2025
Merged
13 tasks
@RossComputerGuy RossComputerGuy force-pushed the fix/pkgsllvm/stdenv branch 2 times, most recently from 8e018d7 to 31c3a2e Compare July 31, 2025 16:26
@RossComputerGuy
Copy link
Member Author

RossComputerGuy commented Jul 31, 2025

It looks like setting COMPILER_RT_DISABLE_AARCH64_FMV is a better non-linux specific way forward here.

Done and I've verified this to work correctly, it was blocking me for testing #429745 & #402198 since compiler-rt was failing. This should be gtg now, I'll merge once this gets approved.

peterwaller-arm
peterwaller-arm reviewed Jul 31, 2025
View reviewed changes
@nixpkgs-ci nixpkgs-ci bot added 10.rebuild-darwin-stdenv This PR causes stdenv to rebuild on Darwin and must target a staging branch. 11.by: package-maintainer This PR was created by a maintainer of all the package it changes. 10.rebuild-darwin: 5001+ This PR causes many rebuilds on Darwin and must target the staging branches. labels Sep 1, 2025
alyssais
alyssais approved these changes Sep 1, 2025
View reviewed changes
Copy link
Member

@alyssais alyssais left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks good but needs to go to staging.

@nixpkgs-ci nixpkgs-ci bot added 12.approvals: 1 This PR was reviewed and approved by one person. 12.approved-by: package-maintainer This PR was reviewed and approved by a maintainer listed in any of the changed packages. labels Sep 1, 2025
@RossComputerGuy RossComputerGuy marked this pull request as draft September 1, 2025 15:34
@RossComputerGuy RossComputerGuy changed the base branch from master to staging September 1, 2025 15:35
@ofborg ofborg bot added the ofborg-internal-error Ofborg encountered an error label Sep 1, 2025
@nixpkgs-ci nixpkgs-ci bot closed this Sep 1, 2025
@nixpkgs-ci nixpkgs-ci bot reopened this Sep 1, 2025
@RossComputerGuy RossComputerGuy marked this pull request as ready for review September 1, 2025 15:35
@ofborg ofborg bot removed the ofborg-internal-error Ofborg encountered an error label Sep 1, 2025
@RossComputerGuy
llvmPackages_{20,21,git}.compiler-rt: no fmv on aarch64 without libc
ded560c 
aarch64 FMV (Function MultiVersioning) is not available before the libc
is available. This causes issues while building with compiler-rt on
aarch64. By disabling FMV before the libc is available resolves missing
symbol errors.
@RossComputerGuy
Copy link
Member Author

RossComputerGuy commented Sep 13, 2025

Rebasing to fix CI

@nix-owners nix-owners bot requested a review from emilazy September 13, 2025 16:33
@RossComputerGuy RossComputerGuy merged commit 4a9d557 into NixOS:staging Sep 13, 2025
27 of 31 checks passed
@RossComputerGuy RossComputerGuy deleted the fix/pkgsllvm/stdenv branch September 13, 2025 16:40
@nixpkgs-ci
Copy link
Contributor

nixpkgs-ci bot commented Sep 13, 2025

Successfully created backport PR for staging-25.05:

@github-actions github-actions bot added the 8.has: port to stable This PR already has a backport to the stable release. label Sep 13, 2025
@nixpkgs-ci nixpkgs-ci bot mentioned this pull request Sep 13, 2025
Merged
1 task
@emilazy
Copy link
Member

emilazy commented Sep 18, 2025

This doesn’t appear to be necessary for Darwin – should we undo it there? I suppose haveLibc is always effectively true on macOS.

@RossComputerGuy
Copy link
Member Author

RossComputerGuy commented Sep 18, 2025

I had pointed that out that this only really is needed for useLLVM. #409265 (comment)

@alyssais
Copy link
Member

alyssais commented Sep 18, 2025

Sounds like we should adjust the definition of haveLibc.

@peterwaller-arm
Copy link
Contributor

peterwaller-arm commented Sep 18, 2025

This doesn’t appear to be necessary for Darwin – should we undo it there?

@emilazy Per the diff, if haveLibc is always true on Darwin, it should not have any effect on Darwin, no? Can you help me parse your comment? I guess this leads to @alyssais's comment.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@alyssais alyssais alyssais approved these changes

@Ericson2314 Ericson2314 Awaiting requested review from Ericson2314

@dtzWill dtzWill Awaiting requested review from dtzWill

@rrbutani rrbutani Awaiting requested review from rrbutani

@lovek323 lovek323 Awaiting requested review from lovek323

@sternenseemann sternenseemann Awaiting requested review from sternenseemann

@emilazy emilazy Awaiting requested review from emilazy

+1 more reviewer

@peterwaller-arm peterwaller-arm peterwaller-arm left review comments

Reviewers whose approvals may not affect merge requirements

Assignees

No one assigned

Labels

6.topic: llvm/clang Issues related to llvmPackages, clangStdenv and related 8.has: port to stable This PR already has a backport to the stable release. 10.rebuild-darwin: 501+ This PR causes many rebuilds on Darwin and should normally target the staging branches. 10.rebuild-darwin: 5001+ This PR causes many rebuilds on Darwin and must target the staging branches. 10.rebuild-darwin-stdenv This PR causes stdenv to rebuild on Darwin and must target a staging branch. 10.rebuild-linux: 101-500 This PR causes between 101 and 500 packages to rebuild on Linux. 11.by: package-maintainer This PR was created by a maintainer of all the package it changes. 12.approvals: 1 This PR was reviewed and approved by one person. 12.approved-by: package-maintainer This PR was reviewed and approved by a maintainer listed in any of the changed packages.

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

Build failure: libcxx with LLVM+LLD on aarch64-linux

6 participants

@RossComputerGuy @alyssais @peterwaller-arm @Ericson2314 @emilazy @Artturin