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Diffstat (limited to '')
| -rwxr-xr-x | git-clang-format | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/git-clang-format b/git-clang-format new file mode 100755 index 0000000..6a0db27 --- /dev/null +++ b/git-clang-format @@ -0,0 +1,484 @@ +#!/usr/bin/env python +# +#===- git-clang-format - ClangFormat Git Integration ---------*- python -*--===# +# +# The LLVM Compiler Infrastructure +# +# This file is distributed under the University of Illinois Open Source +# License. See LICENSE.TXT for details. +# +#===------------------------------------------------------------------------===# + +r""" +clang-format git integration +============================ + +This file provides a clang-format integration for git. Put it somewhere in your +path and ensure that it is executable. Then, "git clang-format" will invoke +clang-format on the changes in current files or a specific commit. + +For further details, run: +git clang-format -h + +Requires Python 2.7 +""" + +import argparse +import collections +import contextlib +import errno +import os +import re +import subprocess +import sys + +usage = 'git clang-format [OPTIONS] [<commit>] [--] [<file>...]' + +desc = ''' +Run clang-format on all lines that differ between the working directory +and <commit>, which defaults to HEAD. Changes are only applied to the working +directory. + +The following git-config settings set the default of the corresponding option: + clangFormat.binary + clangFormat.commit + clangFormat.extension + clangFormat.style +''' + +# Name of the temporary index file in which save the output of clang-format. +# This file is created within the .git directory. +temp_index_basename = 'clang-format-index' + + +Range = collections.namedtuple('Range', 'start, count') + + +def main(): + config = load_git_config() + + # In order to keep '--' yet allow options after positionals, we need to + # check for '--' ourselves. (Setting nargs='*' throws away the '--', while + # nargs=argparse.REMAINDER disallows options after positionals.) + argv = sys.argv[1:] + try: + idx = argv.index('--') + except ValueError: + dash_dash = [] + else: + dash_dash = argv[idx:] + argv = argv[:idx] + + default_extensions = ','.join([ + # From clang/lib/Frontend/FrontendOptions.cpp, all lower case + 'c', 'h', # C + 'm', # ObjC + 'mm', # ObjC++ + 'cc', 'cp', 'cpp', 'c++', 'cxx', 'hpp', # C++ + # Other languages that clang-format supports + 'proto', 'protodevel', # Protocol Buffers + 'js', # JavaScript + ]) + + p = argparse.ArgumentParser( + usage=usage, formatter_class=argparse.RawDescriptionHelpFormatter, + description=desc) + p.add_argument('--binary', + default=config.get('clangformat.binary', 'clang-format'), + help='path to clang-format'), + p.add_argument('--commit', + default=config.get('clangformat.commit', 'HEAD'), + help='default commit to use if none is specified'), + p.add_argument('--diff', action='store_true', + help='print a diff instead of applying the changes') + p.add_argument('--extensions', + default=config.get('clangformat.extensions', + default_extensions), + help=('comma-separated list of file extensions to format, ' + 'excluding the period and case-insensitive')), + p.add_argument('-f', '--force', action='store_true', + help='allow changes to unstaged files') + p.add_argument('-p', '--patch', action='store_true', + help='select hunks interactively') + p.add_argument('-q', '--quiet', action='count', default=0, + help='print less information') + p.add_argument('--style', + default=config.get('clangformat.style', None), + help='passed to clang-format'), + p.add_argument('-v', '--verbose', action='count', default=0, + help='print extra information') + # We gather all the remaining positional arguments into 'args' since we need + # to use some heuristics to determine whether or not <commit> was present. + # However, to print pretty messages, we make use of metavar and help. + p.add_argument('args', nargs='*', metavar='<commit>', + help='revision from which to compute the diff') + p.add_argument('ignored', nargs='*', metavar='<file>...', + help='if specified, only consider differences in these files') + opts = p.parse_args(argv) + + opts.verbose -= opts.quiet + del opts.quiet + + commit, files = interpret_args(opts.args, dash_dash, opts.commit) + changed_lines = compute_diff_and_extract_lines(commit, files) + if opts.verbose >= 1: + ignored_files = set(changed_lines) + filter_by_extension(changed_lines, opts.extensions.lower().split(',')) + if opts.verbose >= 1: + ignored_files.difference_update(changed_lines) + if ignored_files: + print 'Ignoring changes in the following files (wrong extension):' + for filename in ignored_files: + print ' ', filename + if changed_lines: + print 'Running clang-format on the following files:' + for filename in changed_lines: + print ' ', filename + if not changed_lines: + print 'no modified files to format' + return + # The computed diff outputs absolute paths, so we must cd before accessing + # those files. + cd_to_toplevel() + old_tree = create_tree_from_workdir(changed_lines) + new_tree = run_clang_format_and_save_to_tree(changed_lines, + binary=opts.binary, + style=opts.style) + if opts.verbose >= 1: + print 'old tree:', old_tree + print 'new tree:', new_tree + if old_tree == new_tree: + if opts.verbose >= 0: + print 'clang-format did not modify any files' + elif opts.diff: + print_diff(old_tree, new_tree) + else: + changed_files = apply_changes(old_tree, new_tree, force=opts.force, + patch_mode=opts.patch) + if (opts.verbose >= 0 and not opts.patch) or opts.verbose >= 1: + print 'changed files:' + for filename in changed_files: + print ' ', filename + + +def load_git_config(non_string_options=None): + """Return the git configuration as a dictionary. + + All options are assumed to be strings unless in `non_string_options`, in which + is a dictionary mapping option name (in lower case) to either "--bool" or + "--int".""" + if non_string_options is None: + non_string_options = {} + out = {} + for entry in run('git', 'config', '--list', '--null').split('\0'): + if entry: + name, value = entry.split('\n', 1) + if name in non_string_options: + value = run('git', 'config', non_string_options[name], name) + out[name] = value + return out + + +def interpret_args(args, dash_dash, default_commit): + """Interpret `args` as "[commit] [--] [files...]" and return (commit, files). + + It is assumed that "--" and everything that follows has been removed from + args and placed in `dash_dash`. + + If "--" is present (i.e., `dash_dash` is non-empty), the argument to its + left (if present) is taken as commit. Otherwise, the first argument is + checked if it is a commit or a file. If commit is not given, + `default_commit` is used.""" + if dash_dash: + if len(args) == 0: + commit = default_commit + elif len(args) > 1: + die('at most one commit allowed; %d given' % len(args)) + else: + commit = args[0] + object_type = get_object_type(commit) + if object_type not in ('commit', 'tag'): + if object_type is None: + die("'%s' is not a commit" % commit) + else: + die("'%s' is a %s, but a commit was expected" % (commit, object_type)) + files = dash_dash[1:] + elif args: + if disambiguate_revision(args[0]): + commit = args[0] + files = args[1:] + else: + commit = default_commit + files = args + else: + commit = default_commit + files = [] + return commit, files + + +def disambiguate_revision(value): + """Returns True if `value` is a revision, False if it is a file, or dies.""" + # If `value` is ambiguous (neither a commit nor a file), the following + # command will die with an appropriate error message. + run('git', 'rev-parse', value, verbose=False) + object_type = get_object_type(value) + if object_type is None: + return False + if object_type in ('commit', 'tag'): + return True + die('`%s` is a %s, but a commit or filename was expected' % + (value, object_type)) + + +def get_object_type(value): + """Returns a string description of an object's type, or None if it is not + a valid git object.""" + cmd = ['git', 'cat-file', '-t', value] + p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE) + stdout, stderr = p.communicate() + if p.returncode != 0: + return None + return stdout.strip() + + +def compute_diff_and_extract_lines(commit, files): + """Calls compute_diff() followed by extract_lines().""" + diff_process = compute_diff(commit, files) + changed_lines = extract_lines(diff_process.stdout) + diff_process.stdout.close() + diff_process.wait() + if diff_process.returncode != 0: + # Assume error was already printed to stderr. + sys.exit(2) + return changed_lines + + +def compute_diff(commit, files): + """Return a subprocess object producing the diff from `commit`. + + The return value's `stdin` file object will produce a patch with the + differences between the working directory and `commit`, filtered on `files` + (if non-empty). Zero context lines are used in the patch.""" + cmd = ['git', 'diff-index', '-p', '-U0', commit, '--'] + cmd.extend(files) + p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE) + p.stdin.close() + return p + + +def extract_lines(patch_file): + """Extract the changed lines in `patch_file`. + + The return value is a dictionary mapping filename to a list of (start_line, + line_count) pairs. + + The input must have been produced with ``-U0``, meaning unidiff format with + zero lines of context. The return value is a dict mapping filename to a + list of line `Range`s.""" + matches = {} + for line in patch_file: + match = re.search(r'^\+\+\+\ [^/]+/(.*)', line) + if match: + filename = match.group(1).rstrip('\r\n') + match = re.search(r'^@@ -[0-9,]+ \+(\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: + matches.setdefault(filename, []).append(Range(start_line, line_count)) + return matches + + +def filter_by_extension(dictionary, allowed_extensions): + """Delete every key in `dictionary` that doesn't have an allowed extension. + + `allowed_extensions` must be a collection of lowercase file extensions, + excluding the period.""" + allowed_extensions = frozenset(allowed_extensions) + for filename in dictionary.keys(): + base_ext = filename.rsplit('.', 1) + if len(base_ext) == 1 or base_ext[1].lower() not in allowed_extensions: + del dictionary[filename] + + +def cd_to_toplevel(): + """Change to the top level of the git repository.""" + toplevel = run('git', 'rev-parse', '--show-toplevel') + os.chdir(toplevel) + + +def create_tree_from_workdir(filenames): + """Create a new git tree with the given files from the working directory. + + Returns the object ID (SHA-1) of the created tree.""" + return create_tree(filenames, '--stdin') + + +def run_clang_format_and_save_to_tree(changed_lines, binary='clang-format', + style=None): + """Run clang-format on each file and save the result to a git tree. + + Returns the object ID (SHA-1) of the created tree.""" + def index_info_generator(): + for filename, line_ranges in changed_lines.iteritems(): + mode = oct(os.stat(filename).st_mode) + blob_id = clang_format_to_blob(filename, line_ranges, binary=binary, + style=style) + yield '%s %s\t%s' % (mode, blob_id, filename) + return create_tree(index_info_generator(), '--index-info') + + +def create_tree(input_lines, mode): + """Create a tree object from the given input. + + If mode is '--stdin', it must be a list of filenames. If mode is + '--index-info' is must be a list of values suitable for "git update-index + --index-info", such as "<mode> <SP> <sha1> <TAB> <filename>". Any other mode + is invalid.""" + assert mode in ('--stdin', '--index-info') + cmd = ['git', 'update-index', '--add', '-z', mode] + with temporary_index_file(): + p = subprocess.Popen(cmd, stdin=subprocess.PIPE) + for line in input_lines: + p.stdin.write('%s\0' % line) + p.stdin.close() + if p.wait() != 0: + die('`%s` failed' % ' '.join(cmd)) + tree_id = run('git', 'write-tree') + return tree_id + + +def clang_format_to_blob(filename, line_ranges, binary='clang-format', + style=None): + """Run clang-format on the given file and save the result to a git blob. + + Returns the object ID (SHA-1) of the created blob.""" + clang_format_cmd = [binary, filename] + if style: + clang_format_cmd.extend(['-style='+style]) + clang_format_cmd.extend([ + '-lines=%s:%s' % (start_line, start_line+line_count-1) + for start_line, line_count in line_ranges]) + try: + clang_format = subprocess.Popen(clang_format_cmd, stdin=subprocess.PIPE, + stdout=subprocess.PIPE) + except OSError as e: + if e.errno == errno.ENOENT: + die('cannot find executable "%s"' % binary) + else: + raise + clang_format.stdin.close() + hash_object_cmd = ['git', 'hash-object', '-w', '--path='+filename, '--stdin'] + hash_object = subprocess.Popen(hash_object_cmd, stdin=clang_format.stdout, + stdout=subprocess.PIPE) + clang_format.stdout.close() + stdout = hash_object.communicate()[0] + if hash_object.returncode != 0: + die('`%s` failed' % ' '.join(hash_object_cmd)) + if clang_format.wait() != 0: + die('`%s` failed' % ' '.join(clang_format_cmd)) + return stdout.rstrip('\r\n') + + +@contextlib.contextmanager +def temporary_index_file(tree=None): + """Context manager for setting GIT_INDEX_FILE to a temporary file and deleting + the file afterward.""" + index_path = create_temporary_index(tree) + old_index_path = os.environ.get('GIT_INDEX_FILE') + os.environ['GIT_INDEX_FILE'] = index_path + try: + yield + finally: + if old_index_path is None: + del os.environ['GIT_INDEX_FILE'] + else: + os.environ['GIT_INDEX_FILE'] = old_index_path + os.remove(index_path) + + +def create_temporary_index(tree=None): + """Create a temporary index file and return the created file's path. + + If `tree` is not None, use that as the tree to read in. Otherwise, an + empty index is created.""" + gitdir = run('git', 'rev-parse', '--git-dir') + path = os.path.join(gitdir, temp_index_basename) + if tree is None: + tree = '--empty' + run('git', 'read-tree', '--index-output='+path, tree) + return path + + +def print_diff(old_tree, new_tree): + """Print the diff between the two trees to stdout.""" + # We use the porcelain 'diff' and not plumbing 'diff-tree' because the output + # is expected to be viewed by the user, and only the former does nice things + # like color and pagination. + subprocess.check_call(['git', 'diff', old_tree, new_tree, '--']) + + +def apply_changes(old_tree, new_tree, force=False, patch_mode=False): + """Apply the changes in `new_tree` to the working directory. + + Bails if there are local changes in those files and not `force`. If + `patch_mode`, runs `git checkout --patch` to select hunks interactively.""" + changed_files = run('git', 'diff-tree', '-r', '-z', '--name-only', old_tree, + new_tree).rstrip('\0').split('\0') + if not force: + unstaged_files = run('git', 'diff-files', '--name-status', *changed_files) + if unstaged_files: + print >>sys.stderr, ('The following files would be modified but ' + 'have unstaged changes:') + print >>sys.stderr, unstaged_files + print >>sys.stderr, 'Please commit, stage, or stash them first.' + sys.exit(2) + if patch_mode: + # In patch mode, we could just as well create an index from the new tree + # and checkout from that, but then the user will be presented with a + # message saying "Discard ... from worktree". Instead, we use the old + # tree as the index and checkout from new_tree, which gives the slightly + # better message, "Apply ... to index and worktree". This is not quite + # right, since it won't be applied to the user's index, but oh well. + with temporary_index_file(old_tree): + subprocess.check_call(['git', 'checkout', '--patch', new_tree]) + index_tree = old_tree + else: + with temporary_index_file(new_tree): + run('git', 'checkout-index', '-a', '-f') + return changed_files + + +def run(*args, **kwargs): + stdin = kwargs.pop('stdin', '') + verbose = kwargs.pop('verbose', True) + strip = kwargs.pop('strip', True) + for name in kwargs: + raise TypeError("run() got an unexpected keyword argument '%s'" % name) + p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE, + stdin=subprocess.PIPE) + stdout, stderr = p.communicate(input=stdin) + if p.returncode == 0: + if stderr: + if verbose: + print >>sys.stderr, '`%s` printed to stderr:' % ' '.join(args) + print >>sys.stderr, stderr.rstrip() + if strip: + stdout = stdout.rstrip('\r\n') + return stdout + if verbose: + print >>sys.stderr, '`%s` returned %s' % (' '.join(args), p.returncode) + if stderr: + print >>sys.stderr, stderr.rstrip() + sys.exit(2) + + +def die(message): + print >>sys.stderr, 'error:', message + sys.exit(2) + + +if __name__ == '__main__': + main() |