F38 proposal: LLVM 16 (System-Wide Change proposal)
https://fedoraproject.org/wiki/Changes/LLVM-16
This document represents a proposed Change. As part of the Changes
process, proposals are publicly announced in order to receive
community feedback. This proposal will only be implemented if approved
by the Fedora Engineering Steering Committee.
== Summary ==
Update all llvm sub-projects in Fedora Linux to version 16.
== Owner ==
* Name: [[User:tstellar| Tom Stellard]]
* Email: <tstellar(a)redhat.com>
== Detailed Description ==
All llvm sub-projects in Fedora will be updated to version 16, and
there will be a soname version change for the llvm libraries.
Compatibility packages clang15 and llvm15 will be added to ensure that
packages that currently depend on clang and llvm version 15 libraries
will continue to work.
In addition, the default LTO mode for Fedora packages compiling with
clang will be changed from "Full LTO" to "Thin LTO". "Thin
LTO" uses
much less compiler resources than "Full LTO", and is better tested and
supported by upstream. Note that this will not be a change to clang
itself, but rather a change to the compiler flags for clang in
redhat-rpm-config.
== 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.
** Build release candidates into @fedora-llvm-team/llvm16 COPR.
** Build final release (March 2023) into Rawhide and F38 branches.
* Other developers:
** Maintainers of packages that depend on clang-libs or llvm-libs will
need to update their spec files to depend on the clang15 and llvm15
compatibility packages if they want to rebuild their package and it
does not work with LLVM 16 yet. The key point here is that spec file
changes are only needed if a package is going to be rebuilt after LLVM
16 is added to Fedora. The compatibility packages will ensure that
already built packages continue to work.
* Release engineering: [https://pagure.io/releng/issues/11150]
* Policies and guidelines: N/A (not needed for this Change)
* Trademark approval: N/A (not needed for this Change)
* Alignment with Objectives:
== Upgrade/compatibility impact ==
== How To Test ==
== User Experience ==
== Dependencies ==
This change can be made without updating any other packages. However,
as mention before, packages that need to use LLVM 15 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?) Contingency
mechanism: (What to do? Who will do it?): If there are major problems
with LLVM 16, the compatibility package provide a way for other
packages to continue using LLVM 15.
* Contingency deadline: Final Freeze
* Blocks release? No
== Documentation ==
Release notes will be added for this change.
== Release Notes ==
LLVM sub-projects in Fedora have been updated to version 16:
llvm
clang
lld
lldb
compiler-rt
libomp
llvm-test-suite
libcxx
libcxxabi
python-lit
flang
mlir
polly
libclc
llvm-unwind
llvm-bolt
--
Ben Cotton
He / Him / His
Fedora Program Manager
Red Hat
TZ=America/Indiana/Indianapolis