Changes/LLVM-12

LLVM 12

Summary

Update all llvm sub-projects in Fedora to version 12.

Owner

• Name: Tom Stellard
• Email: <tstellar@redhat.com>

Current status

• Targeted release: Fedora 34
• Last updated: 2021-01-06
• FESCo issue: #2526
• Tracker bug: #1913432
• Release notes tracker: #626

Detailed Description

All llvm sub-projects in Fedora will be updated to version 12, and there will be a soname version change for the llvm libraries. Compatibility packages clang11 and llvm11 will be added to ensure that packages that currently depend on clang and llvm version 11 libraries will continue to work.

Benefit to Fedora

New features and bug fixes provided by the latest version of LLVM.

Scope

• Proposal owners:
  • Review existing llvm and clang compatibility packages and orphan any packages that are no longer used.
  • Request a side-tag.
  • Build llvm11 and clang11 into the side-tag.
  • When the upstream LLVM project releases version 12.0.0-rc1 (Jan 2021), package this and build it into the side tag.
  • Merge side-tag into rawhide prior to the f34 branch date.
  • Continue packaging newer release candidates into rawhide and f34 until the final release is complete (~March 2021)

• Other developers:
  • Maintainers of packages that depend on clang-libs or llvm-libs will need to update their spec files to depend on the clang11 and llvm11 compatibility packages if they want to rebuild their package and it does not work with LLVM 12 yet. The key point here is that spec file changes are only needed if a package is going to be rebuilt after LLVM 12 is added to Fedora. The compatibility packages will ensure that already built packages continue to work.

• Release engineering: [1] (a check of an impact with Release Engineering is needed)

• Policies and guidelines: No policies or guidelines will need to be updated as a result of this change.

• Trademark approval: N/A (not needed for this Change)

Upgrade/compatibility impact

This change should not impact upgradeability.

How To Test

The CI tests for the llvm sub-packages in Fedora will be used to catch regressions that might be potentially introduced by the update to LLVM 12.

User Experience

Users will benefit from new features and bug-fixes in the latest version of LLVM.

Dependencies

This change can be made without updating any other packages. However, as mention before, packages that need to use LLVM 11 will need to update their spec file on their first rebuild after this change.

Contingency Plan

• Contingency mechanism: (What to do? Who will do it?) If there are major problems with LLVM 12, the compatibility package provide a way for other packages to continue using LLVM 11. In the worst case, we could always revert LLVM back to LLVM 11, but this would only happen if their were an unprecedented amount of problems.

• Contingency deadline: Beta Freeze
• Blocks release? No
• Blocks product? None

Documentation

Release notes will be added for this change.

Release Notes

LLVM sub-projects in Fedora have been updated to version 12:

• llvm
• clang
• lld
• lldb
• compiler-rt
• libomp
• llvm-test-suite
• libcxx
• libcxxabi
• python-lit
• flang
• mlir