#!/usr/bin/env python3 # #===- clang-tidy-diff.py - ClangTidy Diff Checker -----------*- python -*--===# # # 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 # #===-----------------------------------------------------------------------===# r""" ClangTidy Diff Checker ====================== This script reads input from a unified diff, runs clang-tidy on all changed files and outputs clang-tidy warnings in changed lines only. This is useful to detect clang-tidy regressions in the lines touched by a specific patch. Example usage for git/svn users: git diff -U0 HEAD^ | clang-tidy-diff.py -p1 svn diff --diff-cmd=diff -x-U0 | \ clang-tidy-diff.py -fix -checks=-*,modernize-use-override """ import argparse import glob import json import multiprocessing import os import re import shutil import subprocess import sys import tempfile import threading import traceback try: import yaml except ImportError: yaml = None is_py2 = sys.version[0] == '2' if is_py2: import Queue as queue else: import queue as queue def run_tidy(task_queue, lock, timeout): watchdog = None while True: command = task_queue.get() try: proc = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE) if timeout is not None: watchdog = threading.Timer(timeout, proc.kill) watchdog.start() stdout, stderr = proc.communicate() with lock: sys.stdout.write(stdout.decode('utf-8') + '\n') sys.stdout.flush() if stderr: sys.stderr.write(stderr.decode('utf-8') + '\n') sys.stderr.flush() except Exception as e: with lock: sys.stderr.write('Failed: ' + str(e) + ': '.join(command) + '\n') finally: with lock: if not (timeout is None or watchdog is None): if not watchdog.is_alive(): sys.stderr.write('Terminated by timeout: ' + ' '.join(command) + '\n') watchdog.cancel() task_queue.task_done() def start_workers(max_tasks, tidy_caller, task_queue, lock, timeout): for _ in range(max_tasks): t = threading.Thread(target=tidy_caller, args=(task_queue, lock, timeout)) t.daemon = True t.start() def merge_replacement_files(tmpdir, mergefile): """Merge all replacement files in a directory into a single file""" # The fixes suggested by clang-tidy >= 4.0.0 are given under # the top level key 'Diagnostics' in the output yaml files mergekey = "Diagnostics" merged = [] for replacefile in glob.iglob(os.path.join(tmpdir, '*.yaml')): content = yaml.safe_load(open(replacefile, 'r')) if not content: continue # Skip empty files. merged.extend(content.get(mergekey, [])) if merged: # MainSourceFile: The key is required by the definition inside # include/clang/Tooling/ReplacementsYaml.h, but the value # is actually never used inside clang-apply-replacements, # so we set it to '' here. output = {'MainSourceFile': '', mergekey: merged} with open(mergefile, 'w') as out: yaml.safe_dump(output, out) else: # Empty the file: open(mergefile, 'w').close() def main(): parser = argparse.ArgumentParser(description= 'Run clang-tidy against changed files, and ' 'output diagnostics only for modified ' 'lines.') parser.add_argument('-clang-tidy-binary', metavar='PATH', default='clang-tidy', help='path to clang-tidy binary') parser.add_argument('-p', metavar='NUM', default=0, help='strip the smallest prefix containing P slashes') parser.add_argument('-regex', metavar='PATTERN', default=None, help='custom pattern selecting file paths to check ' '(case sensitive, overrides -iregex)') parser.add_argument('-iregex', metavar='PATTERN', default= r'.*\.(cpp|cc|c\+\+|cxx|c|cl|h|hpp|m|mm|inc)', help='custom pattern selecting file paths to check ' '(case insensitive, overridden by -regex)') parser.add_argument('-j', type=int, default=1, help='number of tidy instances to be run in parallel.') parser.add_argument('-timeout', type=int, default=None, help='timeout per each file in seconds.') parser.add_argument('-fix', action='store_true', default=False, help='apply suggested fixes') parser.add_argument('-checks', help='checks filter, when not specified, use clang-tidy ' 'default', default='') parser.add_argument('-path', dest='build_path', help='Path used to read a compile command database.') if yaml: parser.add_argument('-export-fixes', metavar='FILE', dest='export_fixes', help='Create a yaml file to store suggested fixes in, ' 'which can be applied with clang-apply-replacements.') parser.add_argument('-extra-arg', dest='extra_arg', action='append', default=[], help='Additional argument to append to the compiler ' 'command line.') parser.add_argument('-extra-arg-before', dest='extra_arg_before', action='append', default=[], help='Additional argument to prepend to the compiler ' 'command line.') parser.add_argument('-quiet', action='store_true', default=False, help='Run clang-tidy in quiet mode') clang_tidy_args = [] argv = sys.argv[1:] if '--' in argv: clang_tidy_args.extend(argv[argv.index('--'):]) argv = argv[:argv.index('--')] args = parser.parse_args(argv) # Extract changed lines for each file. filename = None lines_by_file = {} for line in sys.stdin: match = re.search('^\+\+\+\ \"?(.*?/){%s}([^ \t\n\"]*)' % args.p, line) if match: filename = match.group(2) if filename is None: continue if args.regex is not None: if not re.match('^%s$' % args.regex, filename): continue else: if not re.match('^%s$' % args.iregex, filename, re.IGNORECASE): continue match = re.search('^@@.*\+(\d+)(,(\d+))?', line) if match: start_line = int(match.group(1)) line_count = 1 if match.group(3): line_count = int(match.group(3)) if line_count == 0: continue end_line = start_line + line_count - 1 lines_by_file.setdefault(filename, []).append([start_line, end_line]) if not any(lines_by_file): print("No relevant changes found.") sys.exit(0) max_task_count = args.j if max_task_count == 0: max_task_count = multiprocessing.cpu_count() max_task_count = min(len(lines_by_file), max_task_count) tmpdir = None if yaml and args.export_fixes: tmpdir = tempfile.mkdtemp() # Tasks for clang-tidy. task_queue = queue.Queue(max_task_count) # A lock for console output. lock = threading.Lock() # Run a pool of clang-tidy workers. start_workers(max_task_count, run_tidy, task_queue, lock, args.timeout) # Form the common args list. common_clang_tidy_args = [] if args.fix: common_clang_tidy_args.append('-fix') if args.checks != '': common_clang_tidy_args.append('-checks=' + args.checks) if args.quiet: common_clang_tidy_args.append('-quiet') if args.build_path is not None: common_clang_tidy_args.append('-p=%s' % args.build_path) for arg in args.extra_arg: common_clang_tidy_args.append('-extra-arg=%s' % arg) for arg in args.extra_arg_before: common_clang_tidy_args.append('-extra-arg-before=%s' % arg) for name in lines_by_file: line_filter_json = json.dumps( [{"name": name, "lines": lines_by_file[name]}], separators=(',', ':')) # Run clang-tidy on files containing changes. command = [args.clang_tidy_binary] command.append('-line-filter=' + line_filter_json) if yaml and args.export_fixes: # Get a temporary file. We immediately close the handle so clang-tidy can # overwrite it. (handle, tmp_name) = tempfile.mkstemp(suffix='.yaml', dir=tmpdir) os.close(handle) command.append('-export-fixes=' + tmp_name) command.extend(common_clang_tidy_args) command.append(name) command.extend(clang_tidy_args) task_queue.put(command) # Wait for all threads to be done. task_queue.join() if yaml and args.export_fixes: print('Writing fixes to ' + args.export_fixes + ' ...') try: merge_replacement_files(tmpdir, args.export_fixes) except: sys.stderr.write('Error exporting fixes.\n') traceback.print_exc() if tmpdir: shutil.rmtree(tmpdir) if __name__ == '__main__': main()