antifork/antifork.sh

   1 #!/bin/bash
   2
   3 ##
   4 # \file antifork/antifork.sh
   5 #
   6 # \brief Main script for the Antifork system.
   7 #
   8 # <hr>
   9 #
  10 # <h1><b>Copyright.</b></h1>\n
  11 #
  12 # Antifork for
  13 # PCB, interactive printed circuit board design
  14 # Copyright (C) 2015      Markus "Traumflug" Hitter <mah@jump-ing.de>
  15 #
  16 # This program is free software; you can redistribute it and/or modify
  17 # it under the terms of the GNU General Public License as published by
  18 # the Free Software Foundation; either version 2 of the License, or
  19 # (at your option) any later version.
  20 #
  21 # This program is distributed in the hope that it will be useful,
  22 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 # GNU General Public License for more details.
  25 #
  26 # You should have received a copy of the GNU General Public License
  27 # along with this program; if not, write to the Free Software
  28 # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  29 #
  30 #
  31 # Antifork fetches from known, forked repositores and creates local branches
  32 # of their branches. The point is to make all the hidden stuff visible, to
  33 # allow easy cherry-picking, to allow rebasing, and also to deal with forks
  34 # using StGit (which hilariously messes up a Git repository in a way not
  35 # viewable in gitk).
  36 #
  37 # Along the way, branches in forks can be filtered. This is useful for
  38 # forked branches which simply duplicate branches in the official repo,
  39 # which handle topics already finished and similar stuff.
  40 #
  41 # Antifork is meant to run in local clones, not in the official repo. Copied
  42 # branches are prefixed with the name of the fork when fetched for the first
  43 # time. If a forked branch got updated in the fork and is fetched again, it
  44 # additionally gets the prefix "today-". This means to make it easy to
  45 # recognize changes in hte fork.
  46 #
  47 # Happy antiforking, everybody!
  48 #
  49 #
  50 # Format of the repository description files:
  51 #
  52 #  - The name of the file is also the prefix of the local branch copies.
  53 #
  54 #  - First line is the repository URL.
  55 #
  56 #  - Lines starting with 'ignorebranch' followed by the hash of the last
  57 #    commit of a branch mark remote branches which should be ignored.
  58 #    Typically this is the case when all commits in a branch were reviewed and
  59 #    found to be not helpful or the branch was picked to the official repo
  60 #    already.
  61 #
  62 #    It's the last known (stale) commit instead of the branch name,
  63 #    because if there appear new commits on the branch, the branch
  64 #    should be reviewed again.
  65 #
  66 #
  67 # TODO: also allow to ignore single commits, for example by changing their
  68 #       commit message to "obsolete" and squashing consecutive obsolete commits.
  69 #       This should help reviewing a lot.
  70 #
  71 #       Not exactly trivial, because this requires rebasing and rebasing
  72 #       changes the commit hash.
  73
  74 BASE_CMD=$(basename "$0")
  75
  76 if ! ls -d "${BASE_CMD}" >/dev/null 2>&1; then
  77   echo "Run ${BASE_CMD} from the directory it sits in."
  78   exit 1
  79 fi
  80
  81 # Handle parameters.
  82 while [ "${1}" != "" ]; do
  83   case "${1}" in
  84     -h|--help)
  85       echo
  86       echo "  This script attaches a number of known repositores and creates"
  87       echo "  local branches from their branches. The point is to make all the"
  88       echo "  hidden stuff visible."
  89       echo
  90       echo "  -h,--help    Show this help."
  91       echo
  92       echo "  --also-svn   Also attach and fetch forks done in Subversion"
  93       echo "               repositories. These integrate not too well, so"
  94       echo "               they're ignored by default."
  95       echo
  96       echo "  Running ${BASE_CMD} without parameters fetches these"
  97       echo "  repositories:"
  98       echo
  99       echo "    name              location"
 100       echo
 101       for REPO in *; do
 102         if [ "${REPO}" != "${BASE_CMD}" ]; then
 103           printf "    %-16s  " "${REPO}"
 104           head -1 "${REPO}"
 105         fi
 106       done
 107       echo
 108       echo "  Passing one or more of the names as parameters fetches only the"
 109       echo "  given ones."
 110       exit
 111       ;;
 112     --also-svn)
 113       ALSO_SVN="true"
 114       shift
 115       ;;
 116     *)
 117       if [ -r "${1}" ]; then
 118         REPOS=("${REPOS[@]}" "${1}")
 119       else
 120         echo -n "$(basename "$0"): no description file found for repository "
 121         echo    "'${1}'. Dropping."
 122       fi
 123       shift
 124       ;;
 125   esac
 126 done
 127
 128 # No parameters case.
 129 if [ ${#REPOS[*]} = 0 ]; then
 130   for REPO in *; do
 131     if [ "${REPO}" != "${BASE_CMD}" ]; then
 132       REPOS=("${REPOS[@]}" "${REPO}")
 133     fi
 134   done
 135 fi
 136
 137
 138 # Get into action on Git forks.
 139 for REPO in "${REPOS[@]}"; do
 140
 141   URL=$(head -1 "${REPO}")
 142   if [ "${URL}" != "${URL#svn}" ]; then
 143     echo "Eeeek! ${REPO} = ${URL} is a Subversion repo!"
 144     continue
 145   fi
 146
 147   git remote add "${REPO}" "${URL}"
 148   echo -n "Fetching ${REPO} ..."
 149   git fetch "${REPO}" >/dev/null
 150   echo " done."
 151
 152   git branch -r | grep "${REPO}/" | grep -v ".stgit" | \
 153     while read BRANCH; do
 154       LOCAL_BRANCH=$(echo "${BRANCH}" | tr -d ' ' | tr / -)
 155       TODAY_BRANCH="today-${LOCAL_BRANCH}"
 156       RAW_BRANCH=$(git show -q "${BRANCH}" | awk '{ print $2; exit; }')
 157
 158       if cat "${REPO}" | grep "^ignorebranch" | grep -q "${RAW_BRANCH}"; then
 159         echo "Ignoring ${BRANCH}."
 160         if git show -q "${LOCAL_BRANCH}" >/dev/null 2>&1; then
 161           git branch -D "${LOCAL_BRANCH}"
 162         fi
 163         continue
 164       else
 165         echo "Handling ${BRANCH}."
 166       fi
 167
 168       if git show -q "${LOCAL_BRANCH}" >/dev/null 2>&1; then
 169         # Local branch exists.
 170         if git show -q "${TODAY_BRANCH}" >/dev/null 2>&1; then
 171           # Today branch exists. Make it the new LOCAL_BRANCH.
 172           git branch -M "${TODAY_BRANCH}" "${LOCAL_BRANCH}"
 173         fi
 174
 175         # If the remote branch changed, make it a TODAY_BRANCH.
 176         if [ "$(git show -q "${BRANCH}" | head -1)" != \
 177              "$(git show -q "${LOCAL_BRANCH}" | head -1)" ]
 178         then
 179           git branch "${TODAY_BRANCH}" "${BRANCH}"
 180         fi
 181       else
 182         # NO local branch.
 183         git branch "${LOCAL_BRANCH}" "${BRANCH}"
 184       fi
 185
 186     done
 187
 188   git remote remove "${REPO}"
 189
 190 done
 191
 192 if [ -z "${ALSO_SVN}" ]; then
 193   echo "Ignoring forks in Subversion repositories."
 194   exit 0
 195 fi
 196
 197 # Handle Subversion repos.
 198 #
 199 # Cloning a Subversion repo is a very time consuming operation, so we handle
 200 # these entirely different:
 201 #
 202 #  - Don't drop the clone after being done. Actually, Git has no function to
 203 #    remove a SVN remote repo once added. See below on how to do it anyways.
 204 #
 205 #  - Just fetch the branches, no further handling.
 206 #
 207 # Advantage for our purposes here is, branching an dealing with branches
 208 # is rather expensive with SVN, so developers using SVN do so rarely. They
 209 # also can't rebase, so even topic branches can't change.
 210 for REPO in "${REPOS[@]}"; do
 211
 212   URL=$(head -1 "${REPO}")
 213   if [ "${URL}" = "${URL#svn}" ]; then
 214     continue
 215   fi
 216
 217   ORG_PWD="$(pwd)"
 218   trap "cd '${ORG_PWD}'" 0
 219
 220   while ! ls -d .git >/dev/null 2>&1; do
 221     cd ..
 222     if [ "$(pwd)" = "/" ]; then
 223       echo "Not inside a Git repo ?!?."
 224       exit 1
 225     fi
 226   done
 227
 228   if ! git branch -a | grep -q "${REPO}/"; then
 229     # We have no clone, yet.
 230     git svn init --stdlayout --svn-remote="${REPO}" --prefix="${REPO}/" "${URL}"
 231   fi
 232
 233   echo -n "Fetching ${REPO} ... "
 234   git svn fetch "${REPO}"
 235   echo " done."
 236
 237 done
 238
 239 #
 240 # How to remove a SVN remote with the name XYZ from a Git repository.
 241 #
 242 # Note: to the best of my research there is no official Git documentation on
 243 #       how to do this, so make sure you have a backup of your Git repo
 244 #       (a simple copy of the directory is sufficient) and: use this on your
 245 #       own risk!  --Traumflug 2015-08-22
 246 #
 247 # 1. git checkout master
 248 #
 249 # 2. vi .git/config
 250 #
 251 #    Remove the section '[svn-remote "XYZ"]'. All lines up to the next '[' or
 252 #    to the end of file.
 253 #
 254 # 3. vi .git/svn/.metadata
 255 #
 256 #    Do the very same as in 2.
 257 #
 258 # 4. rm -r .git/logs/refs/remotes/XYZ
 259 #
 260 # 5. rm -r .git/svn/refs/remotes/XYZ
 261 #
 262 # 6. rm -r .git/refs/remotes/XYZ
 263 #
 264 # 7. git svn gc
 265 #    git gc
 266 #
 267 # The remote is removed now. To also remove the branches once created by the
 268 # SVN remote, do this:
 269 #
 270 # 8. git branch -a | grep remotes/rnd/ | while read B; do
 271 #      git branch -rD "${B#remotes/}";
 272 #    done
 273 #