1#!/bin/sh
2self="$0"
3dirname_self=$(dirname "$self")
4
5usage() {
6  cat <<EOF >&2
7Usage: $self [option]
8
9This script applies a whitespace transformation to the commit at HEAD. If no
10options are given, then the modified files are left in the working tree.
11
12Options:
13  -h, --help     Shows this message
14  -n, --dry-run  Shows a diff of the changes to be made.
15  --amend        Squashes the changes into the commit at HEAD
16                     This option will also reformat the commit message.
17  --commit       Creates a new commit containing only the whitespace changes
18  --msg-only     Reformat the commit message only, ignore the patch itself.
19
20EOF
21  rm -f ${CLEAN_FILES}
22  exit 1
23}
24
25
26log() {
27  echo "${self##*/}: $@" >&2
28}
29
30
31vpx_style() {
32  for f; do
33    case "$f" in
34      *.h|*.c|*.cc)
35        "${dirname_self}"/vpx-astyle.sh "$f"
36        ;;
37    esac
38  done
39}
40
41
42apply() {
43  [ $INTERSECT_RESULT -ne 0 ] && patch -p1 < "$1"
44}
45
46
47commit() {
48  LAST_CHANGEID=$(git show | awk '/Change-Id:/{print $2}')
49  if [ -z "$LAST_CHANGEID" ]; then
50    log "HEAD doesn't have a Change-Id, unable to generate a new commit"
51    exit 1
52  fi
53
54  # Build a deterministic Change-Id from the parent's
55  NEW_CHANGEID=${LAST_CHANGEID}-styled
56  NEW_CHANGEID=I$(echo $NEW_CHANGEID | git hash-object --stdin)
57
58  # Commit, preserving authorship from the parent commit.
59  git commit -a -C HEAD > /dev/null
60  git commit --amend -F- << EOF
61Cosmetic: Fix whitespace in change ${LAST_CHANGEID:0:9}
62
63Change-Id: ${NEW_CHANGEID}
64EOF
65}
66
67
68show_commit_msg_diff() {
69  if [ $DIFF_MSG_RESULT -ne 0 ]; then
70    log "Modified commit message:"
71    diff -u "$ORIG_COMMIT_MSG" "$NEW_COMMIT_MSG" | tail -n +3
72  fi
73}
74
75
76amend() {
77  show_commit_msg_diff
78  if [ $DIFF_MSG_RESULT -ne 0 ] || [ $INTERSECT_RESULT -ne 0 ]; then
79    git commit -a --amend -F "$NEW_COMMIT_MSG"
80  fi
81}
82
83
84diff_msg() {
85  git log -1 --format=%B > "$ORIG_COMMIT_MSG"
86  "${dirname_self}"/wrap-commit-msg.py \
87      < "$ORIG_COMMIT_MSG" > "$NEW_COMMIT_MSG"
88  cmp -s "$ORIG_COMMIT_MSG" "$NEW_COMMIT_MSG"
89  DIFF_MSG_RESULT=$?
90}
91
92
93# Temporary files
94ORIG_DIFF=orig.diff.$$
95MODIFIED_DIFF=modified.diff.$$
96FINAL_DIFF=final.diff.$$
97ORIG_COMMIT_MSG=orig.commit-msg.$$
98NEW_COMMIT_MSG=new.commit-msg.$$
99CLEAN_FILES="${ORIG_DIFF} ${MODIFIED_DIFF} ${FINAL_DIFF}"
100CLEAN_FILES="${CLEAN_FILES} ${ORIG_COMMIT_MSG} ${NEW_COMMIT_MSG}"
101
102# Preconditions
103[ $# -lt 2 ] || usage
104
105# Check that astyle supports pad-header and align-pointer=name
106if ! astyle --pad-header --align-pointer=name < /dev/null; then
107  log "Install astyle v1.24 or newer"
108  exit 1
109fi
110
111if ! git diff --quiet HEAD; then
112  log "Working tree is dirty, commit your changes first"
113  exit 1
114fi
115
116# Need to be in the root
117cd "$(git rev-parse --show-toplevel)"
118
119# Collect the original diff
120git show > "${ORIG_DIFF}"
121
122# Apply the style guide on new and modified files and collect its diff
123for f in $(git diff HEAD^ --name-only -M90 --diff-filter=AM); do
124  case "$f" in
125    third_party/*) continue;;
126  esac
127  vpx_style "$f"
128done
129git diff --no-color --no-ext-diff > "${MODIFIED_DIFF}"
130
131# Intersect the two diffs
132"${dirname_self}"/intersect-diffs.py \
133    "${ORIG_DIFF}" "${MODIFIED_DIFF}" > "${FINAL_DIFF}"
134INTERSECT_RESULT=$?
135git reset --hard >/dev/null
136
137# Fixup the commit message
138diff_msg
139
140# Handle options
141if [ -n "$1" ]; then
142  case "$1" in
143    -h|--help) usage;;
144    -n|--dry-run) cat "${FINAL_DIFF}"; show_commit_msg_diff;;
145    --commit) apply "${FINAL_DIFF}"; commit;;
146    --amend) apply "${FINAL_DIFF}"; amend;;
147    --msg-only) amend;;
148    *) usage;;
149  esac
150else
151  apply "${FINAL_DIFF}"
152  if ! git diff --quiet; then
153    log "Formatting changes applied, verify and commit."
154    log "See also: http://www.webmproject.org/code/contribute/conventions/"
155    git diff --stat
156  fi
157fi
158
159rm -f ${CLEAN_FILES}
160