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-rwxr-xr-xgit-clang-format484
1 files changed, 484 insertions, 0 deletions
diff --git a/git-clang-format b/git-clang-format
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--- /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()