GH-45885: [C++] Require C++20 #48414

pitrou · 2025-12-09T09:52:34Z

Rationale for this change

We decided to migrate Arrow C++ to C++20 in this discussion: https://lists.apache.org/thread/48zlj0dn2y0f53y2k37qsr90y781wfnj

What changes are included in this PR?

Build configuration updates (CMake files etc.) to build with C++20 instead of C++17
C++-level fixes to ensure compilation succeeds:
- Workarounds for deprecation of atomic access on std::shared_ptr<T> (the replacement std::atomic<std::shared_ptr<T>> is unfortunately not supported in all standard library implementations)
- Workaround for Abseil ABI issues
- Trivial update to arrow/util/string.h to call a C++20 API (to validate that C++20 is actually enabled)
CI configuration updates to get enough C++20 support on the various platforms:
- Bump default clang and LLVM versions to 18
- Use AlmaLinux 10 for release verification (AlmaLinux 8 is still tested on other CI builds)

Are these changes tested?

Yes.

Are there any user-facing changes?

Yes, Arrow C++ will now require a C++20-compliant compiler.

GitHub Issue: [C++][Docs] Update minimum GCC to 8 and C++ standard to C++20 #45885

pitrou · 2025-12-09T11:09:05Z

@github-actions crossbow submit -g cpp

pitrou · 2025-12-09T12:47:09Z

@github-actions crossbow submit -g cpp

pitrou · 2025-12-09T13:35:25Z

@github-actions crossbow submit wheelcp313*

pitrou · 2025-12-09T15:07:20Z

@github-actions crossbow submit -g python

pitrou · 2025-12-09T15:07:43Z

@github-actions crossbow submit -g r

pitrou · 2025-12-15T09:10:32Z

@github-actions crossbow submit -g c-glib -g ruby -g r

github-actions · 2025-12-17T16:50:59Z

Revision: 9d8b52f

Submitted crossbow builds: ursacomputing/crossbow @ actions-037a71b82f

Task	Status
test-debian-c-glib
test-debian-ruby
test-ubuntu-c-glib
test-ubuntu-ruby

pitrou · 2025-12-17T16:53:03Z

@github-actions crossbow submit -g verify-rc

github-actions · 2025-12-17T16:55:49Z

Revision: 9d8b52f

Submitted crossbow builds: ursacomputing/crossbow @ actions-264dd4e180

Task	Status
verify-rc-source-cpp-linux-almalinux-10-amd64
verify-rc-source-cpp-linux-conda-latest-amd64
verify-rc-source-cpp-linux-ubuntu-22.04-amd64
verify-rc-source-cpp-linux-ubuntu-24.04-amd64
verify-rc-source-cpp-macos-amd64
verify-rc-source-cpp-macos-arm64
verify-rc-source-cpp-macos-conda-amd64
verify-rc-source-integration-linux-almalinux-10-amd64
verify-rc-source-integration-linux-conda-latest-amd64
verify-rc-source-integration-linux-ubuntu-22.04-amd64
verify-rc-source-integration-linux-ubuntu-24.04-amd64
verify-rc-source-integration-macos-amd64
verify-rc-source-integration-macos-arm64
verify-rc-source-integration-macos-conda-amd64
verify-rc-source-python-linux-almalinux-10-amd64
verify-rc-source-python-linux-conda-latest-amd64
verify-rc-source-python-linux-ubuntu-22.04-amd64
verify-rc-source-python-linux-ubuntu-24.04-amd64
verify-rc-source-python-macos-amd64
verify-rc-source-python-macos-arm64
verify-rc-source-python-macos-conda-amd64
verify-rc-source-ruby-linux-almalinux-10-amd64
verify-rc-source-ruby-linux-conda-latest-amd64
verify-rc-source-ruby-linux-ubuntu-22.04-amd64
verify-rc-source-ruby-linux-ubuntu-24.04-amd64
verify-rc-source-ruby-macos-amd64
verify-rc-source-ruby-macos-arm64
verify-rc-source-windows

zanmato1984

+1

pitrou · 2025-12-18T13:49:50Z

I think all review comments have been addressed, have I overlooked something @kou @WillAyd @zanmato1984 ?

pitrou · 2025-12-18T13:53:12Z

@github-actions crossbow submit -g r -g cpp -g python

github-actions · 2025-12-18T13:57:12Z

Revision: 6f165ed

Submitted crossbow builds: ursacomputing/crossbow @ actions-370fa26cd6

Task	Status
example-cpp-minimal-build-static
example-cpp-minimal-build-static-system-dependency
example-cpp-tutorial
example-python-minimal-build-fedora-conda
example-python-minimal-build-ubuntu-venv
r-binary-packages
r-recheck-most
test-build-cpp-fuzz
test-conda-cpp
test-conda-cpp-valgrind
test-conda-python-3.10
test-conda-python-3.10-hdfs-2.9.2
test-conda-python-3.10-hdfs-3.2.1
test-conda-python-3.10-pandas-1.3.4-numpy-1.21.2
test-conda-python-3.11
test-conda-python-3.11-dask-latest
test-conda-python-3.11-dask-upstream_devel
test-conda-python-3.11-hypothesis
test-conda-python-3.11-pandas-latest-numpy-latest
test-conda-python-3.11-spark-master
test-conda-python-3.12
test-conda-python-3.12-cpython-debug
test-conda-python-3.12-pandas-latest-numpy-1.26
test-conda-python-3.12-pandas-latest-numpy-latest
test-conda-python-3.13
test-conda-python-3.13-pandas-nightly-numpy-nightly
test-conda-python-3.13-pandas-upstream_devel-numpy-nightly
test-conda-python-3.14
test-conda-python-emscripten
test-cuda-cpp-ubuntu-22.04-cuda-11.7.1
test-cuda-cpp-ubuntu-24.04-cuda-13.0.2
test-cuda-python-ubuntu-22.04-cuda-11.7.1
test-cuda-python-ubuntu-24.04-cuda-13.0.2
test-debian-12-cpp-amd64
test-debian-12-cpp-i386
test-debian-12-python-3-amd64
test-debian-12-python-3-i386
test-debian-experimental-cpp-gcc-15
test-fedora-42-cpp
test-fedora-42-python-3
test-r-alpine-linux-cran
test-r-arrow-backwards-compatibility
test-r-depsource-bundled
test-r-depsource-system
test-r-dev-duckdb
test-r-devdocs
test-r-extra-packages
test-r-gcc-11
test-r-gcc-12
test-r-install-local
test-r-install-local-minsizerel
test-r-linux-as-cran
test-r-linux-rchk
test-r-linux-sanitizers
test-r-linux-valgrind
test-r-m1-san
test-r-macos-as-cran
test-r-minimal-build
test-r-offline-maximal
test-r-offline-minimal
test-r-rhub-debian-gcc-devel-lto-latest
test-r-rhub-ubuntu-gcc12-custom-ccache
test-r-rhub-ubuntu-release-latest
test-r-rocker-r-ver-latest
test-r-rstudio-r-base-4.2-jammy
test-r-ubuntu-22.04
test-r-versions
test-ubuntu-22.04-cpp
test-ubuntu-22.04-cpp-20
test-ubuntu-22.04-cpp-bundled
test-ubuntu-22.04-cpp-emscripten
test-ubuntu-22.04-cpp-no-threading
test-ubuntu-22.04-python-3
test-ubuntu-22.04-python-313-freethreading
test-ubuntu-24.04-cpp
test-ubuntu-24.04-cpp-bundled-offline
test-ubuntu-24.04-cpp-gcc-13-bundled
test-ubuntu-24.04-cpp-gcc-14
test-ubuntu-24.04-cpp-minimal-with-formats
test-ubuntu-24.04-cpp-thread-sanitizer
test-ubuntu-24.04-python-3

pitrou · 2025-12-18T15:00:57Z

I'm not sure what it's for, but I've re-enabled the test-debian-experimental-cpp-gcc-15 job.

pitrou · 2025-12-18T15:01:10Z

@github-actions crossbow submit test-debian-experimental-cpp-gcc-15

github-actions · 2025-12-18T15:03:43Z

Revision: 6fa77b0

Submitted crossbow builds: ursacomputing/crossbow @ actions-93c23edec8

Task	Status
test-debian-experimental-cpp-gcc-15

pitrou · 2025-12-18T15:25:33Z

@github-actions crossbow submit -g cpp -g python

github-actions · 2025-12-18T15:29:01Z

Revision: 6fa77b0

Submitted crossbow builds: ursacomputing/crossbow @ actions-e5d2f93e4c

Task	Status
example-cpp-minimal-build-static
example-cpp-minimal-build-static-system-dependency
example-cpp-tutorial
example-python-minimal-build-fedora-conda
example-python-minimal-build-ubuntu-venv
test-build-cpp-fuzz
test-conda-cpp
test-conda-cpp-valgrind
test-conda-python-3.10
test-conda-python-3.10-hdfs-2.9.2
test-conda-python-3.10-hdfs-3.2.1
test-conda-python-3.10-pandas-1.3.4-numpy-1.21.2
test-conda-python-3.11
test-conda-python-3.11-dask-latest
test-conda-python-3.11-dask-upstream_devel
test-conda-python-3.11-hypothesis
test-conda-python-3.11-pandas-latest-numpy-latest
test-conda-python-3.11-spark-master
test-conda-python-3.12
test-conda-python-3.12-cpython-debug
test-conda-python-3.12-pandas-latest-numpy-1.26
test-conda-python-3.12-pandas-latest-numpy-latest
test-conda-python-3.13
test-conda-python-3.13-pandas-nightly-numpy-nightly
test-conda-python-3.13-pandas-upstream_devel-numpy-nightly
test-conda-python-3.14
test-conda-python-emscripten
test-cuda-cpp-ubuntu-22.04-cuda-11.7.1
test-cuda-cpp-ubuntu-24.04-cuda-13.0.2
test-cuda-python-ubuntu-22.04-cuda-11.7.1
test-cuda-python-ubuntu-24.04-cuda-13.0.2
test-debian-12-cpp-amd64
test-debian-12-cpp-i386
test-debian-12-python-3-amd64
test-debian-12-python-3-i386
test-debian-experimental-cpp-gcc-15
test-fedora-42-cpp
test-fedora-42-python-3
test-ubuntu-22.04-cpp
test-ubuntu-22.04-cpp-20
test-ubuntu-22.04-cpp-bundled
test-ubuntu-22.04-cpp-emscripten
test-ubuntu-22.04-cpp-no-threading
test-ubuntu-22.04-python-3
test-ubuntu-22.04-python-313-freethreading
test-ubuntu-24.04-cpp
test-ubuntu-24.04-cpp-bundled-offline
test-ubuntu-24.04-cpp-gcc-13-bundled
test-ubuntu-24.04-cpp-gcc-14
test-ubuntu-24.04-cpp-minimal-with-formats
test-ubuntu-24.04-cpp-thread-sanitizer
test-ubuntu-24.04-python-3

pitrou · 2025-12-18T16:16:50Z

Well, let's merge this now.

kou · 2025-12-19T01:07:06Z

cpp/src/arrow/CMakeLists.txt


 foreach(LIB_TARGET ${ARROW_LIBRARIES})
  target_compile_definitions(${LIB_TARGET} PRIVATE ARROW_EXPORTING)
  # C++17 is required to compile against Arrow C++ headers and libraries


Could you update this "C++17" too?

Oops, sorry, it's intriguing that I overlooked these two occurrences.

kou · 2025-12-19T01:09:36Z

matlab/tools/cmake/BuildMatlabArrowInterface.cmake

    INCLUDE_DIRS ${MATLAB_ARROW_LIBMEXCLASS_CLIENT_PROXY_LIBRARY_INCLUDE_DIRS}
    LINK_LIBRARIES arrow_shared
 )
 # Use C++17


Could you update this too?

kou · 2025-12-19T01:27:41Z

I'm not sure what it's for, but I've re-enabled the test-debian-experimental-cpp-gcc-15 job.

It's for the latest GCC. We should bump this GCC version when new GCC is released. Debian experimental will provide it. For example, GCC 16 isn't released yet but it's already provided: https://packages.debian.org/search?keywords=gcc-16

### Rationale for this change As a followup to #48414, fix the comments that I had forgotten to update. ### Are these changes tested? No testing required. ### Are there any user-facing changes? No. Authored-by: Antoine Pitrou <antoine@python.org> Signed-off-by: Nic Crane <thisisnic@gmail.com>

### Rationale for this change As a followup to apache#48414, fix the comments that I had forgotten to update. ### Are these changes tested? No testing required. ### Are there any user-facing changes? No. Authored-by: Antoine Pitrou <antoine@python.org> Signed-off-by: Nic Crane <thisisnic@gmail.com>

conbench-apache-arrow · 2025-12-25T06:06:28Z

After merging your PR, Conbench analyzed the 3 benchmarking runs that have been run so far on merge-commit 30809c6.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 474 possible false positives for unstable benchmarks that are known to sometimes produce them.

github-actions bot added Component: C++ Component: Python Component: FlightRPC Component: GLib Component: MATLAB Component: Documentation labels Dec 9, 2025

pitrou mentioned this pull request Dec 9, 2025

[EXP] GH-44792: [C++] Require C++20 #45445

Closed

github-actions bot added the awaiting review Awaiting review label Dec 9, 2025

pitrou added the CI: Extra: C++ Run extra C++ CI label Dec 9, 2025

pitrou force-pushed the gh45885-cxx20 branch from 39db544 to f272bac Compare December 9, 2025 10:24

github-actions bot added the Component: Gandiva label Dec 9, 2025

This comment was marked as outdated.

Sign in to view

pitrou force-pushed the gh45885-cxx20 branch from f272bac to 69cfc74 Compare December 9, 2025 12:47

This comment was marked as outdated.

Sign in to view

pitrou added the CI: Extra: Package: Linux Run extra Linux Packages CI label Dec 9, 2025

This comment was marked as outdated.

Sign in to view

pitrou force-pushed the gh45885-cxx20 branch from 69cfc74 to 1c42352 Compare December 9, 2025 15:51

This comment was marked as outdated.

Sign in to view

pitrou mentioned this pull request Dec 11, 2025

[C++][Docs] Update minimum GCC to 8 and C++ standard to C++20 #45885

Closed

5 tasks

pitrou force-pushed the gh45885-cxx20 branch from 1c42352 to e654d71 Compare December 15, 2025 09:09

pitrou force-pushed the gh45885-cxx20 branch 2 times, most recently from 4c8506b to 42fbedc Compare December 18, 2025 10:37

zanmato1984 approved these changes Dec 18, 2025

View reviewed changes

pitrou force-pushed the gh45885-cxx20 branch from 42fbedc to 6f165ed Compare December 18, 2025 13:52

apacheGH-45885: [C++] Require C++20

6fa77b0

pitrou force-pushed the gh45885-cxx20 branch from 6f165ed to 6fa77b0 Compare December 18, 2025 15:00

pitrou merged commit 30809c6 into apache:main Dec 18, 2025
66 of 68 checks passed

pitrou removed the awaiting change review Awaiting change review label Dec 18, 2025

pitrou deleted the gh45885-cxx20 branch December 18, 2025 16:17

This was referenced Dec 18, 2025

GH-48433: [C++] Use NDEBUG to fix linkage to abseil libraries #48418

Closed

[C++] libarrow_flight symbol issue with pre-packaged Abseil >= 20240722.0 #48433

Closed

kou reviewed Dec 19, 2025

View reviewed changes

github-actions bot added the awaiting changes Awaiting changes label Dec 19, 2025

pitrou mentioned this pull request Dec 19, 2025

MINOR: [C++] Fix C++17-related comments #48598

Merged

GH-45885: [C++] Require C++20 #48414

GH-45885: [C++] Require C++20 #48414

Uh oh!

Conversation

pitrou commented Dec 9, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Rationale for this change

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

Uh oh!

pitrou commented Dec 9, 2025

Uh oh!

This comment was marked as outdated.

pitrou commented Dec 9, 2025

Uh oh!

This comment was marked as outdated.

pitrou commented Dec 9, 2025

Uh oh!

This comment was marked as outdated.

This comment was marked as outdated.

pitrou commented Dec 9, 2025

Uh oh!

pitrou commented Dec 9, 2025

Uh oh!

This comment was marked as outdated.

This comment was marked as outdated.

This comment was marked as outdated.

This comment was marked as outdated.

pitrou commented Dec 15, 2025

Uh oh!

github-actions bot commented Dec 17, 2025

Uh oh!

pitrou commented Dec 17, 2025

Uh oh!

github-actions bot commented Dec 17, 2025

Uh oh!

zanmato1984 left a comment

Choose a reason for hiding this comment

Uh oh!

pitrou commented Dec 18, 2025

Uh oh!

pitrou commented Dec 18, 2025

Uh oh!

github-actions bot commented Dec 18, 2025

Uh oh!

pitrou commented Dec 18, 2025

Uh oh!

pitrou commented Dec 18, 2025

Uh oh!

github-actions bot commented Dec 18, 2025

Uh oh!

pitrou commented Dec 18, 2025

Uh oh!

github-actions bot commented Dec 18, 2025

Uh oh!

pitrou commented Dec 18, 2025

Uh oh!

Uh oh!

kou Dec 19, 2025

Choose a reason for hiding this comment

Uh oh!

pitrou Dec 19, 2025

Choose a reason for hiding this comment

Uh oh!

kou Dec 19, 2025

Choose a reason for hiding this comment

Uh oh!

kou commented Dec 19, 2025

Uh oh!

conbench-apache-arrow bot commented Dec 25, 2025

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

7 participants

pitrou commented Dec 9, 2025 •

edited

Loading