[libc++][CI] Starts using Clang 17.

[philnik]

libcxx/utils/ci/buildkite-pipeline.yml

293

Why don't you remove the Clang 14 run?

[Mordante]

libcxx/utils/ci/buildkite-pipeline.yml

293

We typically do that after the release branch is released. Then we also can cleanup the clang 14 work-arounds if needed.

[ldionne]

libcxx/utils/ci/buildkite-pipeline.yml

293

FWIW I would be OK with removing the 14 run in this patch, but no strong preference.

[Mordante]

Rebased and addresses review comments

[Mordante]

Thanks for the reviews!

libcxx/utils/ci/buildkite-pipeline.yml

293

I don't feel to strongly about the "current" process. So I've removed it.
(Especially since I want to give the patch a spin before landing it.)

[Mordante]

Try to fix CI.

libcxx/utils/ci/buildkite-pipeline-clang.yml

 #===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 #
 #===----------------------------------------------------------------------===##
 
 #
 # This file describes the various pre-commit CI bots used to test Clang against
 # libc++ under various configurations. Unlike the usual libc++ CI pipeline,
 # which aims to test libc++ itself, this pipeline aims to test Clang by
 # compiling libc++ and running its test suite against the just-built Clang,
 # in various configurations.
 #
 env:
-    LLVM_HEAD_VERSION: "16"
+    LLVM_HEAD_VERSION: "17"
 steps:
   - label: "Building clang"
     commands:
       - "mkdir install"
       - "cmake -S llvm -B build -G Ninja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_INSTALL_PREFIX=install -DLLVM_ENABLE_PROJECTS=\"clang;compiler-rt\""
       - "ninja -C build install-clang install-clang-resource-headers"
       - "buildkite-agent artifact upload 'install/**/*'"
     env:

libcxx/utils/ci/buildkite-pipeline.yml

 #
 
 # The Linux CI runners use the nightly ToT build provided by the Docker image.
 # (Note the image isn't updated daily.) The LLVM_HEAD_VERSION contains that
 # version number. The Linux CI runners for GCC use the latest stable version.
 # Theses numbers are available in all runners, making it easier to update the
 # version number.
 env:
-    LLVM_STABLE_VERSION: "15"
-    LLVM_HEAD_VERSION: "16"
+    LLVM_STABLE_VERSION: "16"
+    LLVM_HEAD_VERSION: "17"
     GCC_STABLE_VERSION: "12"
 steps:
   #
   # Light pre-commit tests for things like formatting or when people forget
   # to update generated files.
   #
   - label: "Format"
     command: "libcxx/utils/ci/run-buildbot check-format"
steps:
   - label: "Generated output"
     command: "libcxx/utils/ci/run-buildbot check-generated-output"
     artifact_paths:
       - "**/generated_output.patch"
       - "**/generated_output.status"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
-        CLANG_FORMAT: "clang-format-${LLVM_STABLE_VERSION}"
+        # TODO ENABLE
+        # CLANG_FORMAT: "/usr/bin/clang-format-${LLVM_STABLE_VERSION}"
+        CLANG_FORMAT: "clang-format-15"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
-  - label: "Clang 14"
+  - label: "Clang 15"
     command: "libcxx/utils/ci/run-buildbot generic-cxx2b"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
-        CC: "clang-14"
-        CXX: "clang++-14"
+        CC: "clang-15"
+        CXX: "clang++-15"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
-  - label: "Clang 15"
+  - label: "Clang 16"
     command: "libcxx/utils/ci/run-buildbot generic-cxx2b"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
-        CC: "clang-15"
-        CXX: "clang++-15"
+        CC: "clang-16"
+        CXX: "clang++-16"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   # Tests with the sanitizers.
   - group: "Sanitizers"
     steps:
     - label: "ASAN"
       command: "libcxx/utils/ci/run-buildbot generic-asan"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env: