vpx/tools/ftfy.sh
John Koleszar cb265a497d FTFY: an automated style corrector
This is a utility for applying a limited amount of style correction on
a change-by-change basis. Rather than a big-bang reformatting, this
tool attempts to only correct the style in diff hunks that you touch.
This should make the cosmetic changes small enough that we can mix them
with functional changes without destroying the diffs, and there's an
escape hatch for separating the reformatting to a second commit for
purists and cases where it hurts readability.

At this time, the script requires a clean working tree, so run it after
you've commited your changes. Run without arguments, the style
corrections will be applied and left unstaged in your working copy. It
also supports the --amend option, which will automatically amend your
HEAD with the corrected style, and --commit, which will create a new
change dependent on your HEAD that contains only the whitespace changes.

There are a number of ways this could be applied in an automated manner
if this proves to be useful, either on a project-wide or per-user
basis. This doesn't buy anything in terms of real code quality, the
intent here would be to keep formatting nits out of review comments in
favor of more meaningful ones and help people whose habitual style
doesn't match the baseline.

Requires astyle[1] 1.24 or newer.
  [1]: http://astyle.sourceforge.net/

Change-Id: I2fb3434de8479655e9811f094029bb90e5d757e1
2012-03-28 14:05:56 -07:00

124 lines
2.8 KiB
Bash
Executable File

#!/bin/sh
self="$0"
usage() {
cat <<EOF >&2
Usage: $self [option]
This script applies a whitespace transformation to the commit at HEAD. If no
options are given, then the modified files are left in the working tree.
Options:
-n, --dry-run Shows a diff of the changes to be made.
--amend Squashes the changes into the commit at HEAD
--commit Creates a new commit containing only the whitespace changes
EOF
rm -f ${CLEAN_FILES}
exit 1
}
log() {
echo "${self##*/}: $@" >&2
}
vpx_style() {
astyle --style=bsd --min-conditional-indent=0 --break-blocks \
--pad-oper --pad-header --unpad-paren \
--align-pointer=name \
--indent-preprocessor --convert-tabs --indent-labels \
--suffix=none --quiet "$@"
sed -i 's/[[:space:]]\{1,\},/,/g' "$@"
}
apply() {
patch -p1 < "$1"
}
commit() {
LAST_CHANGEID=$(git show | awk '/Change-Id:/{print $2}')
if [ -z "$LAST_CHANGEID" ]; then
log "HEAD doesn't have a Change-Id, unable to generate a new commit"
exit 1
fi
# Build a deterministic Change-Id from the parent's
NEW_CHANGEID=${LAST_CHANGEID}-styled
NEW_CHANGEID=I$(echo $NEW_CHANGEID | git hash-object --stdin)
# Commit, preserving authorship from the parent commit.
git commit -a -C HEAD > /dev/null
git commit --amend -F- << EOF
Cosmetic: Fix whitespace in change ${LAST_CHANGEID:0:9}
Change-Id: ${NEW_CHANGEID}
EOF
}
amend() {
git commit -a --amend -C HEAD
}
# Temporary files
ORIG_DIFF=orig.diff.$$
MODIFIED_DIFF=modified.diff.$$
FINAL_DIFF=final.diff.$$
CLEAN_FILES="${ORIG_DIFF} ${MODIFIED_DIFF} ${FINAL_DIFF}"
# Preconditions
[ $# -lt 2 ] || usage
if ! git diff --quiet HEAD; then
log "Working tree is dirty, commit your changes first"
exit 1
fi
# Need to be in the root
cd "$(git rev-parse --show-toplevel)"
# Collect the original diff
git show > "${ORIG_DIFF}"
# Apply the style guide on the modified files and collect its diff
for f in $(git diff HEAD^ --name-only | grep '\.[ch]$'); do
case "$f" in
third_party/*) continue;;
nestegg/*) continue;;
esac
vpx_style "$f"
done
git diff --no-color --no-ext-diff > "${MODIFIED_DIFF}"
# Intersect the two diffs
$(dirname ${self})/intersect-diffs.py \
"${ORIG_DIFF}" "${MODIFIED_DIFF}" > "${FINAL_DIFF}"
INTERSECT_RESULT=$?
git reset --hard >/dev/null
if [ $INTERSECT_RESULT -eq 0 ]; then
# Handle options
if [ -n "$1" ]; then
case "$1" in
-h|--help) usage;;
-n|--dry-run) cat "${FINAL_DIFF}";;
--commit) apply "${FINAL_DIFF}"; commit;;
--amend) apply "${FINAL_DIFF}"; amend;;
*) usage;;
esac
else
apply "${FINAL_DIFF}"
if ! git diff --quiet; then
log "Formatting changes applied, verify and commit."
log "See also: http://www.webmproject.org/code/contribute/conventions/"
git diff --stat
fi
fi
fi
rm -f ${CLEAN_FILES}