Enable linting of CMake files using pre-commit

.pre-commit-config.yaml

@@ -70,6 +70,24 @@ repos:
                 language: system
                 files: \.(cu|cuh|h|hpp|cpp|inl)$
                 args: ['-fallback-style=none']
+              - id: cmake-format
+                name: cmake-format
+                entry: bash cpp/scripts/run-cmake-format.sh cmake-format
+                language: python
+                types: [cmake]
+                # Note that pre-commit autoupdate does not update the versions
+                # of dependencies, so we'll have to update this manually.
+                additional_dependencies:
+                  - cmakelang==0.6.13
+              - id: cmake-lint
+                name: cmake-lint
+                entry: bash cpp/scripts/run-cmake-format.sh cmake-lint
+                language: python
+                types: [cmake]
+                # Note that pre-commit autoupdate does not update the versions
+                # of dependencies, so we'll have to update this manually.
+                additional_dependencies:
+                  - cmakelang==0.6.13
 
 default_language_version:
       python: python3

cpp/scripts/run-cmake-format.sh

@@ -0,0 +1,59 @@
+#!/bin/bash
+
+# This script is a pre-commit hook that wraps cmakelang's cmake linters. The
+# wrapping is necessary because RAPIDS libraries split configuration for
+# cmakelang linters between a local config file and a second config file that's
+# shared across all of RAPIDS via rapids-cmake. In order to keep it up to date
+# this file is only maintained in one place (the rapids-cmake repo) and
+# pulled down during builds. We need a way to invoke CMake linting commands
+# without causing pre-commit failures (which could block local commits or CI),
+# while also being sufficiently flexible to allow users to maintain the config
+# file independently of a build directory.
+#
+# This script provides the minimal functionality to enable those use cases. It
+# searches in a number of predefined locations for the rapids-cmake config file
+# and exits gracefully if the file is not found. If a user wishes to specify a
+# config file at a nonstandard location, they may do so by setting the
+# environment variable RAPIDS_CMAKE_FORMAT_FILE.
+# 
+# While this script can be invoked directly (but only from the repo root since
+# all paths are relative to that), it is advisable to instead use the
+# pre-commit hooks via
+# `pre-commit run (cmake-format)|(cmake-format)`.
+#
+# Usage:
+# bash run-cmake-format.sh {cmake-format,cmake-lint} infile [infile ...]
+
+# Note that pre-commit always runs from the root of the repository, so relative
+# paths are automatically relative to the repo root.
+DEFAULT_FORMAT_FILE_LOCATIONS=(
+  "cpp/build/_deps/rapids-cmake-src/cmake-format-rapids-cmake.json" 
+  "${CUDF_ROOT:-${HOME}}/_deps/rapids-cmake-src/cmake-format-rapids-cmake.json"
+  "cpp/libcudf_kafka/build/_deps/rapids-cmake-src/cmake-format-rapids-cmake.json"
+)
+
+if [ -z ${RAPIDS_CMAKE_FORMAT_FILE:+PLACEHOLDER} ]; then
+    for file_path in ${DEFAULT_FORMAT_FILE_LOCATIONS[@]}; do
+        if [ -f ${file_path} ]; then
+            RAPIDS_CMAKE_FORMAT_FILE=${file_path}
+            break
+        fi
+    done
+fi
+
+if [ -z ${RAPIDS_CMAKE_FORMAT_FILE:+PLACEHOLDER} ]; then
+  echo "The rapids-cmake cmake-format configuration file was not found at any of the default search locations: "
+  echo ""
+  ( IFS=$'\n'; echo "${DEFAULT_FORMAT_FILE_LOCATIONS[*]}" )
+  echo ""
+  echo "Try setting the environment variable RAPIDS_CMAKE_FORMAT_FILE to the path to the config file."
+  exit 0
+else
+  echo "Using format file ${RAPIDS_CMAKE_FORMAT_FILE}"
+fi
+
+if [[ $1 == "cmake-format" ]]; then
+  cmake-format -i --config-files cpp/cmake/config.json ${RAPIDS_CMAKE_FORMAT_FILE} -- ${@:2}
+elif [[ $1 == "cmake-lint" ]]; then
+  cmake-lint --config-files cpp/cmake/config.json ${RAPIDS_CMAKE_FORMAT_FILE} -- ${@:2}
+fi