Issue #958: Travis CI should enfore clang-format standards

This patch adds clang format support to the travis bots.

Author: baylesj

.travis.yml

@@ -15,17 +15,18 @@ addons:
   apt:
     sources:
     - ubuntu-toolchain-r-test
-    - llvm-toolchain-xenial-8
+    - llvm-toolchain-xenial-9
     packages:
-    - clang-8
+    - clang-format-9
+    - clang-9
     - valgrind
 matrix:
   allow_failures:
     - os: osx
   include:
     - name: Mac clang meson static release testing
       os: osx
-      osx_image: xcode10.2
+      osx_image: xcode11
       compiler: clang
       env:
          CXX="clang++"

.travis_scripts/meson_builder.sh

@@ -63,9 +63,11 @@ meson --version
 ninja --version
 _COMPILER_NAME=`basename ${CXX}`
 _BUILD_DIR_NAME="build-${BUILD_TYPE}_${LIB_TYPE}_${_COMPILER_NAME}"
+
+./.travis_scripts/run-clang-format.sh
 meson --buildtype ${BUILD_TYPE} --default-library ${LIB_TYPE} . "${_BUILD_DIR_NAME}"
 ninja -v -j 2 -C "${_BUILD_DIR_NAME}"
-#ninja -v -j 2 -C "${_BUILD_DIR_NAME}" test
+
 cd "${_BUILD_DIR_NAME}"
   meson test --no-rebuild --print-errorlogs
 

.travis_scripts/run-clang-format.py

@@ -0,0 +1,356 @@
+#!/usr/bin/env python
+"""A wrapper script around clang-format, suitable for linting multiple files
+and to use for continuous integration.
+This is an alternative API for the clang-format command line.
+It runs over multiple files and directories in parallel.
+A diff output is produced and a sensible exit code is returned.
+
+NOTE: pulled from https://github.com/Sarcasm/run-clang-format, which is
+licensed under the MIT license.
+"""
+
+from __future__ import print_function, unicode_literals
+
+import argparse
+import codecs
+import difflib
+import fnmatch
+import io
+import multiprocessing
+import os
+import signal
+import subprocess
+import sys
+import traceback
+
+from functools import partial
+
+try:
+    from subprocess import DEVNULL  # py3k
+except ImportError:
+    DEVNULL = open(os.devnull, "wb")
+
+
+DEFAULT_EXTENSIONS = 'c,h,C,H,cpp,hpp,cc,hh,c++,h++,cxx,hxx'
+
+
+class ExitStatus:
+    SUCCESS = 0
+    DIFF = 1
+    TROUBLE = 2
+
+
+def list_files(files, recursive=False, extensions=None, exclude=None):
+    if extensions is None:
+        extensions = []
+    if exclude is None:
+        exclude = []
+
+    out = []
+    for file in files:
+        if recursive and os.path.isdir(file):
+            for dirpath, dnames, fnames in os.walk(file):
+                fpaths = [os.path.join(dirpath, fname) for fname in fnames]
+                for pattern in exclude:
+                    # os.walk() supports trimming down the dnames list
+                    # by modifying it in-place,
+                    # to avoid unnecessary directory listings.
+                    dnames[:] = [
+                        x for x in dnames
+                        if
+                        not fnmatch.fnmatch(os.path.join(dirpath, x), pattern)
+                    ]
+                    fpaths = [
+                        x for x in fpaths if not fnmatch.fnmatch(x, pattern)
+                    ]
+                for f in fpaths:
+                    ext = os.path.splitext(f)[1][1:]
+                    if ext in extensions:
+                        out.append(f)
+        else:
+            out.append(file)
+    return out
+
+
+def make_diff(file, original, reformatted):
+    return list(
+        difflib.unified_diff(
+            original,
+            reformatted,
+            fromfile='{}\t(original)'.format(file),
+            tofile='{}\t(reformatted)'.format(file),
+            n=3))
+
+
+class DiffError(Exception):
+    def __init__(self, message, errs=None):
+        super(DiffError, self).__init__(message)
+        self.errs = errs or []
+
+
+class UnexpectedError(Exception):
+    def __init__(self, message, exc=None):
+        super(UnexpectedError, self).__init__(message)
+        self.formatted_traceback = traceback.format_exc()
+        self.exc = exc
+
+
+def run_clang_format_diff_wrapper(args, file):
+    try:
+        ret = run_clang_format_diff(args, file)
+        return ret
+    except DiffError:
+        raise
+    except Exception as e:
+        raise UnexpectedError('{}: {}: {}'.format(file, e.__class__.__name__,
+                                                  e), e)
+
+
+def run_clang_format_diff(args, file):
+    try:
+        with io.open(file, 'r', encoding='utf-8') as f:
+            original = f.readlines()
+    except IOError as exc:
+        raise DiffError(str(exc))
+    invocation = [args.clang_format_executable, file]
+
+    # Use of utf-8 to decode the process output.
+    #
+    # Hopefully, this is the correct thing to do.
+    #
+    # It's done due to the following assumptions (which may be incorrect):
+    # - clang-format will returns the bytes read from the files as-is,
+    #   without conversion, and it is already assumed that the files use utf-8.
+    # - if the diagnostics were internationalized, they would use utf-8:
+    #   > Adding Translations to Clang
+    #   >
+    #   > Not possible yet!
+    #   > Diagnostic strings should be written in UTF-8,
+    #   > the client can translate to the relevant code page if needed.
+    #   > Each translation completely replaces the format string
+    #   > for the diagnostic.
+    #   > -- http://clang.llvm.org/docs/InternalsManual.html#internals-diag-translation
+    #
+    # It's not pretty, due to Python 2 & 3 compatibility.
+    encoding_py3 = {}
+    if sys.version_info[0] >= 3:
+        encoding_py3['encoding'] = 'utf-8'
+
+    try:
+        proc = subprocess.Popen(
+            invocation,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            universal_newlines=True,
+            **encoding_py3)
+    except OSError as exc:
+        raise DiffError(
+            "Command '{}' failed to start: {}".format(
+                subprocess.list2cmdline(invocation), exc
+            )
+        )
+    proc_stdout = proc.stdout
+    proc_stderr = proc.stderr
+    if sys.version_info[0] < 3:
+        # make the pipes compatible with Python 3,
+        # reading lines should output unicode
+        encoding = 'utf-8'
+        proc_stdout = codecs.getreader(encoding)(proc_stdout)
+        proc_stderr = codecs.getreader(encoding)(proc_stderr)
+    # hopefully the stderr pipe won't get full and block the process
+    outs = list(proc_stdout.readlines())
+    errs = list(proc_stderr.readlines())
+    proc.wait()
+    if proc.returncode:
+        raise DiffError(
+            "Command '{}' returned non-zero exit status {}".format(
+                subprocess.list2cmdline(invocation), proc.returncode
+            ),
+            errs,
+        )
+    return make_diff(file, original, outs), errs
+
+
+def bold_red(s):
+    return '\x1b[1m\x1b[31m' + s + '\x1b[0m'
+
+
+def colorize(diff_lines):
+    def bold(s):
+        return '\x1b[1m' + s + '\x1b[0m'
+
+    def cyan(s):
+        return '\x1b[36m' + s + '\x1b[0m'
+
+    def green(s):
+        return '\x1b[32m' + s + '\x1b[0m'
+
+    def red(s):
+        return '\x1b[31m' + s + '\x1b[0m'
+
+    for line in diff_lines:
+        if line[:4] in ['--- ', '+++ ']:
+            yield bold(line)
+        elif line.startswith('@@ '):
+            yield cyan(line)
+        elif line.startswith('+'):
+            yield green(line)
+        elif line.startswith('-'):
+            yield red(line)
+        else:
+            yield line
+
+
+def print_diff(diff_lines, use_color):
+    if use_color:
+        diff_lines = colorize(diff_lines)
+    if sys.version_info[0] < 3:
+        sys.stdout.writelines((l.encode('utf-8') for l in diff_lines))
+    else:
+        sys.stdout.writelines(diff_lines)
+
+
+def print_trouble(prog, message, use_colors):
+    error_text = 'error:'
+    if use_colors:
+        error_text = bold_red(error_text)
+    print("{}: {} {}".format(prog, error_text, message), file=sys.stderr)
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument(
+        '--clang-format-executable',
+        metavar='EXECUTABLE',
+        help='path to the clang-format executable',
+        default='clang-format')
+    parser.add_argument(
+        '--extensions',
+        help='comma separated list of file extensions (default: {})'.format(
+            DEFAULT_EXTENSIONS),
+        default=DEFAULT_EXTENSIONS)
+    parser.add_argument(
+        '-r',
+        '--recursive',
+        action='store_true',
+        help='run recursively over directories')
+    parser.add_argument('files', metavar='file', nargs='+')
+    parser.add_argument(
+        '-q',
+        '--quiet',
+        action='store_true')
+    parser.add_argument(
+        '-j',
+        metavar='N',
+        type=int,
+        default=0,
+        help='run N clang-format jobs in parallel'
+        ' (default number of cpus + 1)')
+    parser.add_argument(
+        '--color',
+        default='auto',
+        choices=['auto', 'always', 'never'],
+        help='show colored diff (default: auto)')
+    parser.add_argument(
+        '-e',
+        '--exclude',
+        metavar='PATTERN',
+        action='append',
+        default=[],
+        help='exclude paths matching the given glob-like pattern(s)'
+        ' from recursive search')
+
+    args = parser.parse_args()
+
+    # use default signal handling, like diff return SIGINT value on ^C
+    # https://bugs.python.org/issue14229#msg156446
+    signal.signal(signal.SIGINT, signal.SIG_DFL)
+    try:
+        signal.SIGPIPE
+    except AttributeError:
+        # compatibility, SIGPIPE does not exist on Windows
+        pass
+    else:
+        signal.signal(signal.SIGPIPE, signal.SIG_DFL)
+
+    colored_stdout = False
+    colored_stderr = False
+    if args.color == 'always':
+        colored_stdout = True
+        colored_stderr = True
+    elif args.color == 'auto':
+        colored_stdout = sys.stdout.isatty()
+        colored_stderr = sys.stderr.isatty()
+
+    version_invocation = [args.clang_format_executable, str("--version")]
+    try:
+        subprocess.check_call(version_invocation, stdout=DEVNULL)
+    except subprocess.CalledProcessError as e:
+        print_trouble(parser.prog, str(e), use_colors=colored_stderr)
+        return ExitStatus.TROUBLE
+    except OSError as e:
+        print_trouble(
+            parser.prog,
+            "Command '{}' failed to start: {}".format(
+                subprocess.list2cmdline(version_invocation), e
+            ),
+            use_colors=colored_stderr,
+        )
+        return ExitStatus.TROUBLE
+
+    retcode = ExitStatus.SUCCESS
+    files = list_files(
+        args.files,
+        recursive=args.recursive,
+        exclude=args.exclude,
+        extensions=args.extensions.split(','))
+
+    if not files:
+        return
+
+    njobs = args.j
+    if njobs == 0:
+        njobs = multiprocessing.cpu_count() + 1
+    njobs = min(len(files), njobs)
+
+    if njobs == 1:
+        # execute directly instead of in a pool,
+        # less overhead, simpler stacktraces
+        it = (run_clang_format_diff_wrapper(args, file) for file in files)
+        pool = None
+    else:
+        pool = multiprocessing.Pool(njobs)
+        it = pool.imap_unordered(
+            partial(run_clang_format_diff_wrapper, args), files)
+    while True:
+        try:
+            outs, errs = next(it)
+        except StopIteration:
+            break
+        except DiffError as e:
+            print_trouble(parser.prog, str(e), use_colors=colored_stderr)
+            retcode = ExitStatus.TROUBLE
+            sys.stderr.writelines(e.errs)
+        except UnexpectedError as e:
+            print_trouble(parser.prog, str(e), use_colors=colored_stderr)
+            sys.stderr.write(e.formatted_traceback)
+            retcode = ExitStatus.TROUBLE
+            # stop at the first unexpected error,
+            # something could be very wrong,
+            # don't process all files unnecessarily
+            if pool:
+                pool.terminate()
+            break
+        else:
+            sys.stderr.writelines(errs)
+            if outs == []:
+                continue
+            if not args.quiet:
+                print_diff(outs, use_color=colored_stdout)
+            if retcode == ExitStatus.SUCCESS:
+                retcode = ExitStatus.DIFF
+    return retcode
+
+
+if __name__ == '__main__':
+    sys.exit(main())

.travis_scripts/run-clang-format.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+python $DIR/run-clang-format.py -r $DIR/../src/**/ $DIR/../include/**/