[libc++][CI] Improves clang-(tidy|query) selection.

[Mordante]

Summary

Hardcode the version of the tools used in the test feature script
instead of the tests. By changing the hard-coded location it's
easier to make the location flexible in the future.

Drive-by change

• The minimum required version for clang-query is now 15, which matches our future idea as outlined in the Dockerfile.
• The minimum required version for clang-tidy is now 16, which enables the new clang-tidy ADL plugin. This plugin is disabled for C++03 due to false positives when using noexcept, which is not an operator in C++03.

[Mordante]

Retrigger CI to start on libc++

[Mordante]

Add a dummy change to trigger libcx++ CI.

[Mordante]

Remove dummy change.

[ldionne]

libcxx/test/configs/cmake-bridge.cfg.in

33

I would like to keep this to the smallest set of substitutions that we need to make the test suite work, so I am not sure about this approach. I'll need to take another look at this when I have more time.

[ldionne]

libcxx/utils/ci/run-buildbot

45–49

This can be removed.

libcxx/utils/libcxx/test/features.py

155–156

I think I would dumb down the whole patch to this. It does mean that only folks with exactly clang-tidy-15 will get those tests enabled, but it's already pretty much the status quo, and doing this avoids piping through the clang-tidy version across multiple layers like buildkite-pipeline.yml and CMake.

We should also do the same for clang-query in the same patch.

If we want to be more clever about finding clang-tidy (e.g. falling back on clang-tidy --version >= 15), we can do something similar to what we do with getStdFlag in params.py and basically do a linear search with various options.

Also, restricting the changes to this means that we avoid adding another dependency from the test suite onto CMake, which is good since we want to strive for the test suite being as freestanding as possible (within reason).

[Mordante]

Thanks for the suggestions.

libcxx/test/configs/cmake-bridge.cfg.in

33

As discussed yesterday with @ldionne we go with a different approach so this change is undone.

libcxx/utils/libcxx/test/features.py

155–156

This didn't work as suggested, I used the same syntax as the bash test above.

[Mordante]

Rebased and use a different approach as discussed with @ldionne during the code review.

[Mordante]

Rebased to test CI.

[Mordante]

CI fixes.

[Mordante]

Another attempt to fix the CI.

[Mordante]

Test the CI, the last time seemed a bit flacky.

[Mordante]

Restart CI.

[Mordante]

CI fixes.

[Mordante]

Retrigger CI.

[Mordante]

Another attempt to start the CI.

[Mordante]

CI test again...

[Mordante]

CI seems not really willing to start.

libcxx/CMakeLists.txt

set(LIBCXX_TEST_CONFIG "${LIBCXX_DEFAULT_TEST_CONFIG}" CACHE STRING
     "The path to the Lit testing configuration to use when running the tests.
      If a relative path is provided, it is assumed to be relative to '<monorepo>/libcxx/test/configs'.")
 if (NOT IS_ABSOLUTE "${LIBCXX_TEST_CONFIG}")
   set(LIBCXX_TEST_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/test/configs/${LIBCXX_TEST_CONFIG}")
 endif()
 message(STATUS "Using libc++ testing configuration: ${LIBCXX_TEST_CONFIG}")
 set(LIBCXX_TEST_PARAMS "" CACHE STRING
     "A list of parameters to run the Lit test suite with.")
+set(LIBCXX_TEST_CLANG_TIDY "" CACHE STRING
+    "The optional clang-tidy version to use in the test suite.")
 
 # Benchmark options -----------------------------------------------------------
 option(LIBCXX_INCLUDE_BENCHMARKS "Build the libc++ benchmarks and their dependencies" ON)
 
 set(LIBCXX_BENCHMARK_TEST_ARGS_DEFAULT --benchmark_min_time=0.01)
 set(LIBCXX_BENCHMARK_TEST_ARGS "${LIBCXX_BENCHMARK_TEST_ARGS_DEFAULT}" CACHE STRING
     "Arguments to pass when running the benchmarks using check-cxx-benchmarks")
 

libcxx/test/configs/cmake-bridge.cfg.in

 # Add substitutions for bootstrapping the test suite configuration
 import shlex
 config.substitutions.append(('%{cxx}', shlex.quote('@CMAKE_CXX_COMPILER@')))
 config.substitutions.append(('%{libcxx}', '@LIBCXX_SOURCE_DIR@'))
 config.substitutions.append(('%{include}', '@LIBCXX_GENERATED_INCLUDE_DIR@'))
 config.substitutions.append(('%{target-include}', '@LIBCXX_GENERATED_INCLUDE_TARGET_DIR@'))
 config.substitutions.append(('%{lib}', '@LIBCXX_LIBRARY_DIR@'))
 config.substitutions.append(('%{executor}', '@LIBCXX_EXECUTOR@'))
+config.substitutions.append(('%{clang-tidy}', shlex.quote('@LIBCXX_TEST_CLANG_TIDY@')))

libcxx/test/libcxx/clang_tidy.sh.cpp

 //===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-clang-tidy
 
 // The GCC compiler flags are not always compatible with clang-tidy.
 // UNSUPPORTED: gcc
 
 // TODO: run clang-tidy with modules enabled once they are supported
-// RUN: clang-tidy %s --warnings-as-errors=* -header-filter=.* --config-file=%S/../../.clang-tidy -- -Wweak-vtables %{compile_flags} -fno-modules
+// RUN: %{clang-tidy} %s --warnings-as-errors=* -header-filter=.* --config-file=%S/../../.clang-tidy -- -Wweak-vtables %{compile_flags} -fno-modules
 
 // Prevent <ext/hash_map> from generating deprecated warnings for this test.
 #if defined(__DEPRECATED)
 #    undef __DEPRECATED
 #endif
 
 /*
 BEGIN-SCRIPT

libcxx/utils/ci/buildkite-pipeline.yml

steps:
   - label: "GCC ${GCC_STABLE_VERSION} / C++latest"
     command: "libcxx/utils/ci/run-buildbot generic-gcc"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "gcc-${GCC_STABLE_VERSION}"
         CXX: "g++-${GCC_STABLE_VERSION}"
+        # Some of GCC's warning flags are not supported by clang-tidy.
+        # Therefore clang-tidy is not used in the GCC build.
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "C++2b"
     command: "libcxx/utils/ci/run-buildbot generic-cxx2b"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "Modular build"
     command: "libcxx/utils/ci/run-buildbot generic-modules"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "C++11"
     command: "libcxx/utils/ci/run-buildbot generic-cxx11"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "C++03"
     command: "libcxx/utils/ci/run-buildbot generic-cxx03"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   #
   # All other supported configurations of libc++.
   #
   - wait
 
   - label: "C++20"
     command: "libcxx/utils/ci/run-buildbot generic-cxx20"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "C++17"
     command: "libcxx/utils/ci/run-buildbot generic-cxx17"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "C++14"
     command: "libcxx/utils/ci/run-buildbot generic-cxx14"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   # Tests with the supported compilers.
   - label: "GCC ${GCC_STABLE_VERSION} / C++11"
     command: "libcxx/utils/ci/run-buildbot generic-gcc-cxx11"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "gcc-${GCC_STABLE_VERSION}"
         CXX: "g++-${GCC_STABLE_VERSION}"
+        # Some of GCC's warning flags are not supported by clang-tidy.
+        # Therefore clang-tidy is not used in the GCC build.
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "Clang 14"
     command: "libcxx/utils/ci/run-buildbot generic-cxx2b"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-14"
         CXX: "clang++-14"
+        CLANG_TIDY: "/usr/bin/clang-tidy-14"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "Clang 15"
     command: "libcxx/utils/ci/run-buildbot generic-cxx2b"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-15"
         CXX: "clang++-15"
+        CLANG_TIDY: "/usr/bin/clang-tidy-15"
     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:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "TSAN"
       command: "libcxx/utils/ci/run-buildbot generic-tsan"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "UBSAN"
       command: "libcxx/utils/ci/run-buildbot generic-ubsan"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "MSAN"
       command: "libcxx/utils/ci/run-buildbot generic-msan"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
   # Tests with the various supported ways to build libc++.
   - label: "Bootstrapping build"
     command: "libcxx/utils/ci/run-buildbot bootstrapping-build"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
       - "**/crash_diagnostics/*"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
         LLVM_SYMBOLIZER_PATH: "/usr/bin/llvm-symbolizer-${LLVM_HEAD_VERSION}"
         CLANG_CRASH_DIAGNOSTICS_DIR: "crash_diagnostics"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   # Tests with various build configurations.
   - label: "Static libraries"
     command: "libcxx/utils/ci/run-buildbot generic-static"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "Shared library with merged ABI and unwinder libraries"
     command: "libcxx/utils/ci/run-buildbot generic-merged"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "Assertions enabled"
     command: "libcxx/utils/ci/run-buildbot generic-assertions"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "Debug mode"
     command: "libcxx/utils/ci/run-buildbot generic-debug-mode"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "No transitive includes"
     command: "libcxx/utils/ci/run-buildbot generic-no-transitive-includes"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - label: "With LLVM's libunwind"
     command: "libcxx/utils/ci/run-buildbot generic-with_llvm_unwinder"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   - group: "Parts disabled"
     steps:
     - label: "No threads"
       command: "libcxx/utils/ci/run-buildbot generic-no-threads"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "No filesystem"
       command: "libcxx/utils/ci/run-buildbot generic-no-filesystem"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "No random device"
       command: "libcxx/utils/ci/run-buildbot generic-no-random_device"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "No fstream"
       command: "libcxx/utils/ci/run-buildbot generic-no-fstream"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "No locale"
       command: "libcxx/utils/ci/run-buildbot generic-no-localization"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "No Unicode"
       command: "libcxx/utils/ci/run-buildbot generic-no-unicode"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "No wide characters"
       command: "libcxx/utils/ci/run-buildbot generic-no-wide-characters"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "No experimental features"
       command: "libcxx/utils/ci/run-buildbot generic-no-experimental"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "No exceptions"
       command: "libcxx/utils/ci/run-buildbot generic-noexceptions"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       env:
           CC: "clang-${LLVM_HEAD_VERSION}"
           CXX: "clang++-${LLVM_HEAD_VERSION}"
+          CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
   - label: "Unstable ABI"
     command: "libcxx/utils/ci/run-buildbot generic-abi-unstable"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
+        CLANG_TIDY: "/usr/bin/clang-tidy-${LLVM_STABLE_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120

libcxx/utils/ci/run-buildbot

 
 --build-dir <DIR>   The directory to use for building the library. By default,
                     this is '<llvm-root>/build/<builder>'.
 
 --osx-roots <DIR>   Path to pre-downloaded macOS dylibs. By default, we download
                     them from Green Dragon. This is only relevant at all when
                     running back-deployment testing if one wants to override
                     the old dylibs we use to run the tests with different ones.
+Environment variables
+CC                  The C compiler to use, this value is used by CMake. This
+                    variable is optional.
+CXX                 The C++ compiler to use, this value is used by CMake. This
+                    variable is optional.
+
+GIT_CLANG_FORMAT    The git-clang-format binary to use in the 'format' builder.
+                    When the value is omitted, it defaults to
+                    'git-clang-format'. This variable or its fallback must work
+                    when running the 'format' builder.
+CLANG_TIDY          The clang-tidy binary to use in the unit tests. When the
+                    value is omitted, it defaults to 'clang-tidy.exe' on Windows
+                    and 'clang-tidy' on other platforms. The unit test validate
+                    whether the executable can be used, if not the tests
+                    requiring clang-tidy are unsupported.
 EOF
 }
 
+if [[ $# == 0 ]]; then
+   usage
+   exit 0
+fi
+
 while [[ $# -gt 0 ]]; do
     case ${1} in
         -h|--help)
             usage
             exit 0
             ;;
         --llvm-root)
             MONOREPO_ROOT="${2}"
${CMAKE} \
           -DLIBCXX_ENABLE_WERROR=YES \
           -DLIBCXXABI_ENABLE_WERROR=YES \
           -DLIBUNWIND_ENABLE_WERROR=YES \
           -DLLVM_LIT_ARGS="-sv --show-unsupported --xunit-xml-output test-results.xml --timeout=1500 --time-tests" \
           "${@}"
 }
 
 function generate-cmake() {
+    if [ -z "${CLANG_TIDY}" ]; then
+       CLANG_TIDY=clang-tidy
+    fi
     generate-cmake-base \
           -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind" \
           -DLIBCXX_CXX_ABI=libcxxabi \
+          -DLIBCXX_TEST_CLANG_TIDY="${CLANG_TIDY}" \
           "${@}"
 }
 
 function generate-cmake-libcxx-win() {
     # TODO: Clang-cl in MSVC configurations don't have access to compiler_rt
     # builtins helpers for int128 division. See
     # https://reviews.llvm.org/D91139#2429595 for a comment about longterm
     # intent for handling the issue. In the meantime, define
     # -D_LIBCPP_HAS_NO_INT128 (both when building the library itself and
     # when building tests) to allow enabling filesystem for running tests,
     # even if it uses a non-permanent ABI.
+    if [ -z "${CLANG_TIDY}" ]; then
+       CLANG_TIDY=clang-tidy.exe
+    fi
     generate-cmake-base \
           -DLLVM_ENABLE_RUNTIMES="libcxx" \
           -DCMAKE_C_COMPILER=clang-cl \
           -DCMAKE_CXX_COMPILER=clang-cl \
           -DLIBCXX_ENABLE_FILESYSTEM=YES \
           -DLIBCXX_EXTRA_SITE_DEFINES="_LIBCPP_HAS_NO_INT128" \
+          -DLIBCXX_TEST_CLANG_TIDY="${CLANG_TIDY}" \
           "${@}"
 }
 
 function check-runtimes() {
     echo "--- Installing libc++, libc++abi and libunwind to a fake location"
     ${NINJA} -vC "${BUILD_DIR}" install-cxx install-cxxabi install-unwind
 
     echo "+++ Running the libc++ tests"

libcxx/utils/libcxx/test/features.py

 _isClang      = lambda cfg: '__clang__' in compilerMacros(cfg) and '__apple_build_version__' not in compilerMacros(cfg)
 _isAppleClang = lambda cfg: '__apple_build_version__' in compilerMacros(cfg)
 _isGCC        = lambda cfg: '__GNUC__' in compilerMacros(cfg) and '__clang__' not in compilerMacros(cfg)
 _isMSVC       = lambda cfg: '_MSC_VER' in compilerMacros(cfg)
 _msvcVersion  = lambda cfg: (int(compilerMacros(cfg)['_MSC_VER']) // 100, int(compilerMacros(cfg)['_MSC_VER']) % 100)
 
 def _hasSuitableClangTidy(cfg):
   try:
-    return int(re.search('[0-9]+', commandOutput(cfg, ['clang-tidy --version'])).group()) >= 13
+    return int(re.search('[0-9]+', commandOutput(cfg, ['%{clang-tidy} --version'])).group()) >= 14
   except ConfigurationRuntimeError:
     return False
 
 def _hasSuitableClangQuery(cfg):
   try:
-    return int(re.search('[0-9]+', commandOutput(cfg, ['clang-query --version'])).group()) >= 13
+    return int(re.search('[0-9]+', commandOutput(cfg, ['clang-query --version'])).group()) >= 14
   except ConfigurationRuntimeError:
     return False
 
 DEFAULT_FEATURES = [
   Feature(name='fcoroutines-ts',
           when=lambda cfg: hasCompileFlag(cfg, '-fcoroutines-ts') and
                            featureTestMacros(cfg, flags='-fcoroutines-ts').get('__cpp_coroutines', 0) >= 201703,
           actions=[AddCompileFlag('-fcoroutines-ts')]),
DEFAULT_FEATURES = [
   #
   # For the corner case of bash existing, but it being missing in the path
   # set in %{exec} as "--env PATH=one-single-dir", the executor does find
   # and executes bash, but bash then can't find any other common shell
   # utilities. Test executing "bash -c 'bash --version'" to see if bash
   # manages to find binaries to execute.
   Feature(name='executor-has-no-bash',
           when=lambda cfg: runScriptExitCode(cfg, ['%{exec} bash -c \'bash --version\'']) != 0),
   Feature(name='has-clang-tidy',
           when=_hasSuitableClangTidy),
   Feature(name='has-clang-query',
           when=_hasSuitableClangQuery),
 
   Feature(name='apple-clang',                                                                                                      when=_isAppleClang),
   Feature(name=lambda cfg: 'apple-clang-{__clang_major__}'.format(**compilerMacros(cfg)),                                          when=_isAppleClang),
   Feature(name=lambda cfg: 'apple-clang-{__clang_major__}.{__clang_minor__}'.format(**compilerMacros(cfg)),                        when=_isAppleClang),
   Feature(name=lambda cfg: 'apple-clang-{__clang_major__}.{__clang_minor__}.{__clang_patchlevel__}'.format(**compilerMacros(cfg)), when=_isAppleClang),