From c44336573bf88c00230962204c3d8739cc03c54d Mon Sep 17 00:00:00 2001
From: patrick96 <p.ziegler96@gmail.com>
Date: Tue, 27 Sep 2022 23:42:29 +0200
Subject: [PATCH] build: Create clangformat(-dryrun) build targets

The clangformat target updates all files in-place while the
clangformat-dryrun target prints an error message for each format-change
clang-format would apply.
The latter exits with a non-zero error code if there are any changes.
---
 .editorconfig          |  3 +++
 cmake/04-targets.cmake | 20 ++++++++++++-----
 common/clang-format.sh | 20 -----------------
 common/file-runner.py  | 50 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 68 insertions(+), 25 deletions(-)
 delete mode 100755 common/clang-format.sh
 create mode 100755 common/file-runner.py

diff --git a/.editorconfig b/.editorconfig
index 57c08e6e..ff6aa42b 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -7,6 +7,9 @@ indent_style = space
 indent_size = 2
 charset = utf-8
 
+[*.py]
+indent_size = 4
+
 [Makefile]
 indent_style = tab
 indent_size = 2
diff --git a/cmake/04-targets.cmake b/cmake/04-targets.cmake
index 7424341b..0c1e8f51 100644
--- a/cmake/04-targets.cmake
+++ b/cmake/04-targets.cmake
@@ -17,13 +17,23 @@ add_custom_target(uninstall
 # folders where the clang tools should operate
 set(CLANG_SEARCH_PATHS ${PROJECT_SOURCE_DIR}/src ${PROJECT_SOURCE_DIR}/include ${PROJECT_SOURCE_DIR}/tests)
 
-# Target: codeformat (clang-format) {{{
+# Runs clang-format on all source files
+add_custom_target(
+  clangformat
+  COMMAND ${PROJECT_SOURCE_DIR}/common/file-runner.py
+  --dirs ${CLANG_SEARCH_PATHS}
+  -- clang-format -style=file -i --verbose
+  )
 
-add_custom_target(codeformat)
-add_custom_command(TARGET codeformat
-  COMMAND ${PROJECT_SOURCE_DIR}/common/clang-format.sh ${CLANG_SEARCH_PATHS})
+# Dry-runs clang-format on all source files
+# Useful for CI since it will exit with an error code
+add_custom_target(
+  clangformat-dryrun
+  COMMAND ${PROJECT_SOURCE_DIR}/common/file-runner.py
+  --dirs ${CLANG_SEARCH_PATHS}
+  -- clang-format -style=file --dry-run -Werror --verbose
+  )
 
-# }}}
 # Target: codecheck (clang-tidy) {{{
 
 add_custom_target(codecheck)
diff --git a/common/clang-format.sh b/common/clang-format.sh
deleted file mode 100755
index 0a912c8e..00000000
--- a/common/clang-format.sh
+++ /dev/null
@@ -1,20 +0,0 @@
-#!/bin/sh
-
-main() {
-  if [ $# -lt 1 ]; then
-    echo "$0 DIR..." 1>&2
-    exit 1
-  fi
-
-  # Search paths
-  search="${*:-.}"
-
-  echo "$0 in $search"
-
-  # shellcheck disable=2086
-  find $search -regex ".*.[c|h]pp"                           \
-    -exec printf "\\033[32;1m** \\033[0mFormatting %s\\n" {} \; \
-    -exec clang-format -style=file -i {} \;
-}
-
-main "$@"
diff --git a/common/file-runner.py b/common/file-runner.py
new file mode 100755
index 00000000..a4d97c9f
--- /dev/null
+++ b/common/file-runner.py
@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+
+from pathlib import Path
+import sys
+import os
+import argparse
+import subprocess
+
+EXTENSIONS = set('.' + ext for ext in ['c', 'h', 'cpp', 'hpp', 'inl'])
+
+
+def get_files(dirs):
+    """
+    Generator which yields all files in the given directories with any of the
+    EXTENSIONS.
+    """
+    for dir in dirs:
+        for root, _, files in os.walk(dir):
+            for file in files:
+                path = Path(os.path.join(root, file))
+                if path.suffix in EXTENSIONS:
+                    yield path
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="""
+        Run command on all C/C++ source files in the given directories
+        """)
+    parser.add_argument('--dirs', type=Path, nargs='+',
+                        help='Directories to search in')
+    parser.add_argument('command', nargs='+',
+                        help='Command to which to pass found files')
+    args = parser.parse_args()
+
+    all_files = list(str(file) for file in get_files(args.dirs))
+
+    if not all_files:
+        print("No files found")
+        sys.exit(1)
+
+    result = subprocess.run(args.command + all_files)
+    print(f'Formatted {len(all_files)} files')
+
+    if result.returncode != 0:
+        sys.exit(result.returncode)
+
+
+if __name__ == '__main__':
+    main()