pre-commit: Add clang-tidy hook

.clang-tidy

@@ -0,0 +1,7 @@
+---
+Checks:          '-*,modernize-use-nullptr,modernize-use-auto'
+WarningsAsErrors: ''
+HeaderFilterRegex: ''
+AnalyzeTemporaryDtors: false
+FormatStyle:     none
+...

.pre-commit-config.yaml

@@ -74,17 +74,32 @@ repos:
     stages:
     - commit
     - manual
+- repo: local
+  hooks:
+  - id: clang-tidy
+    name: clang-tidy
+    entry: tools/clang_tidy.py
+    require_serial: true
+    verbose: true
+    stages:
+    - commit
+    - manual
+    language: system
+    files: \.(c|cc|cxx|cpp|frag|glsl|h|hpp|hxx|ih|ispc|ipp|java|js|m|mm|proto|vert)$
+    additional_dependencies:
+    - clang-tidy
 - repo: local
   hooks:
   - id: clang-format
     name: clang-format
-    entry: tools/clang_format_wrapper.py
+    description: "Run clang-format in two passes (reformat, then break long lines)"
+    entry: tools/clang_format.py
     require_serial: true
     stages:
     - commit
     - manual
     language: python
-    files: \.(c|cc|cxx|cpp|frag|glsl|h|hpp|hxx|ih|ispc|ipp|java|js|m|mm|proto|vert)$
+    files: \.(c|cc|cxx|cpp|frag|glsl|h|hpp|hxx|ih|ispc|ipp|java|m|mm|proto|vert)$
     additional_dependencies:
     - clang-format
 - repo: https://github.com/psf/black
@@ -114,14 +129,3 @@ repos:
     stages:
     - commit
     - manual
-- repo: local
-  hooks:
-  - id: line-length
-    name: line-length
-    description: Check for lines longer 100 and brakes them before 80.
-    entry: ./tools/line_length.py
-    stages:
-    - commit
-    - manual
-    language: python
-    files: \.(c|cpp|h)$

CMakeLists.txt

@@ -319,6 +319,13 @@ if(CMAKE_VERSION VERSION_LESS "3.7.0")
   set(CMAKE_INCLUDE_CURRENT_DIR ON)
 endif()
 
+# Export compile-commands.json and symlink it into the source directory (needed
+# for clang-tidy pre-commit hook)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+file(CREATE_LINK
+  ${CMAKE_BINARY_DIR}/compile_commands.json
+  ${CMAKE_SOURCE_DIR}/compile_commands.json SYMBOLIC)
+
 # Mixxx itself
 add_library(mixxx-lib STATIC EXCLUDE_FROM_ALL
   src/analyzer/analyzerbeats.cpp

tools/clang_format.py

@@ -0,0 +1,137 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+import argparse
+import logging
+import os
+import re
+import subprocess
+import sys
+import tempfile
+import typing
+
+import githelper
+
+
+# We recommend a maximum line length of 80, but do allow up to 100 characters
+# if deemed necessary by the developer. Lines that exceed that limit will
+# be wrapped after 80 characters automatically.
+LINE_LENGTH_THRESHOLD = 100
+BREAK_BEFORE = 80
+
+
+def get_clang_format_config_with_columnlimit(rootdir, limit):
+    """Create a temporary config with ColumnLimit set to 80."""
+    cpp_file = os.path.join(rootdir, "src/mixxx.cpp")
+    proc = subprocess.run(
+        ["clang-format", "--dump-config", cpp_file],
+        capture_output=True,
+        text=True,
+    )
+    proc.check_returncode()
+    return re.sub(
+        r"(ColumnLimit:\s*)\d+", r"\g<1>{}".format(BREAK_BEFORE), proc.stdout
+    )
+
+
+def run_clang_format_on_lines(rootdir, file_to_format, stylepath=None):
+    logger = logging.getLogger(__name__)
+
+    line_arguments = [
+        "--lines={}:{}".format(start, end)
+        for start, end in file_to_format.lines
+    ]
+    assert line_arguments
+
+    logger.info("Reformatting %s...", file_to_format.filename)
+    filename = os.path.join(rootdir, file_to_format.filename)
+    cmd = [
+        "clang-format",
+        "--style=file",
+        # The --assume-filename argument sets the path for the .clang-format
+        # config file implcitly by assuming a different location of the file to
+        # format
+        "--assume-filename={}".format(
+            os.path.join(
+                stylepath if stylepath else rootdir, file_to_format.filename
+            )
+        ),
+        *line_arguments,
+    ]
+
+    with open(filename) as fp:
+        logger.debug("Executing: %r", cmd)
+        proc = subprocess.run(cmd, stdin=fp, capture_output=True, text=True)
+    try:
+        proc.check_returncode()
+    except subprocess.CalledProcessError:
+        logger.error(
+            "Error while executing command %s: %s", cmd, proc.stderr,
+        )
+        raise
+
+    if proc.stderr:
+        logger.error(proc.stderr)
+    with open(filename, mode="w") as fp:
+        fp.write(proc.stdout)
+
+
+def main(argv: typing.Optional[typing.List[str]] = None) -> int:
+    logging.basicConfig(
+        format="[%(levelname)s] %(message)s", level=logging.INFO
+    )
+
+    logger = logging.getLogger(__name__)
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--from-ref", help="use changes changes since commit")
+    parser.add_argument("--to-ref", help="use changes until commit")
+    parser.add_argument("files", nargs="*", help="only check these files")
+    args = parser.parse_args(argv)
+
+    if not args.from_ref:
+        args.from_ref = os.getenv("PRE_COMMIT_FROM_REF") or os.getenv(
+            "PRE_COMMIT_SOURCE"
+        )
+
+    if not args.to_ref:
+        args.to_ref = os.getenv("PRE_COMMIT_TO_REF") or os.getenv(
+            "PRE_COMMIT_ORIGIN"
+        )
+
+    # Filter filenames
+    rootdir = githelper.get_toplevel_path()
+
+    # First pass: Format added/changed lines using clang-format
+    logger.info("First pass: Reformatting added/changed lines...")
+    files_with_added_lines = githelper.get_changed_lines_grouped(
+        from_ref=args.from_ref,
+        to_ref=args.to_ref,
+        filter_lines=lambda line: line.added,
+        include_files=args.files,
+    )
+    for changed_file in files_with_added_lines:
+        run_clang_format_on_lines(rootdir, changed_file)
+
+    # Second pass: Wrap long added/changed lines using clang-format
+    logger.info("Second pass: Breaking long added/changed lines...")
+    files_with_long_added_lines = githelper.get_changed_lines_grouped(
+        from_ref=args.from_ref,
+        to_ref=args.to_ref,
+        filter_lines=lambda line: line.added
+        and len(line.text) > LINE_LENGTH_THRESHOLD,
+        include_files=args.files,
+    )
+    config = get_clang_format_config_with_columnlimit(rootdir, BREAK_BEFORE)
+    with tempfile.TemporaryDirectory(prefix="clang-format") as tempdir:
+        # Create temporary config with ColumnLimit enabled
+        configfile = os.path.join(tempdir, ".clang-format")
+        with open(configfile, mode="w") as configfp:
+            configfp.write(config)
+
+        for changed_file in files_with_long_added_lines:
+            run_clang_format_on_lines(rootdir, changed_file, stylepath=tempdir)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())