git-rebase.sh

   1 #!/bin/sh
   2 #
   3 # Copyright (c) 2005 Junio C Hamano.
   4 #
   5
   6 USAGE='[--interactive | -i] [-v] [--onto <newbase>] <upstream> [<branch>]'
   7 LONG_USAGE='git-rebase replaces <branch> with a new branch of the
   8 same name.  When the --onto option is provided the new branch starts
   9 out with a HEAD equal to <newbase>, otherwise it is equal to <upstream>
  10 It then attempts to create a new commit for each commit from the original
  11 <branch> that does not exist in the <upstream> branch.
  12
  13 It is possible that a merge failure will prevent this process from being
  14 completely automatic.  You will have to resolve any such merge failure
  15 and run git rebase --continue.  Another option is to bypass the commit
  16 that caused the merge failure with git rebase --skip.  To restore the
  17 original <branch> and remove the .dotest working files, use the command
  18 git rebase --abort instead.
  19
  20 Note that if <branch> is not specified on the command line, the
  21 currently checked out branch is used.  You must be in the top
  22 directory of your project to start (or continue) a rebase.
  23
  24 Example:       git-rebase master~1 topic
  25
  26         A---B---C topic                   A'\''--B'\''--C'\'' topic
  27        /                   -->           /
  28   D---E---F---G master          D---E---F---G master
  29 '
  30
  31 SUBDIRECTORY_OK=Yes
  32 OPTIONS_SPEC=
  33 . git-sh-setup
  34 set_reflog_action rebase
  35 require_work_tree
  36 cd_to_toplevel
  37
  38 RESOLVEMSG="
  39 When you have resolved this problem run \"git rebase --continue\".
  40 If you would prefer to skip this patch, instead run \"git rebase --skip\".
  41 To restore the original branch and stop rebasing run \"git rebase --abort\".
  42 "
  43 unset newbase
  44 strategy=recursive
  45 do_merge=
  46 dotest=$GIT_DIR/.dotest-merge
  47 prec=4
  48 verbose=
  49 git_am_opt=
  50
  51 continue_merge () {
  52         test -n "$prev_head" || die "prev_head must be defined"
  53         test -d "$dotest" || die "$dotest directory does not exist"
  54
  55         unmerged=$(git ls-files -u)
  56         if test -n "$unmerged"
  57         then
  58                 echo "You still have unmerged paths in your index"
  59                 echo "did you forget to use git add?"
  60                 die "$RESOLVEMSG"
  61         fi
  62
  63         cmt=`cat "$dotest/current"`
  64         if ! git diff-index --quiet HEAD --
  65         then
  66                 if ! git commit --no-verify -C "$cmt"
  67                 then
  68                         echo "Commit failed, please do not call \"git commit\""
  69                         echo "directly, but instead do one of the following: "
  70                         die "$RESOLVEMSG"
  71                 fi
  72                 printf "Committed: %0${prec}d " $msgnum
  73         else
  74                 printf "Already applied: %0${prec}d " $msgnum
  75         fi
  76         git rev-list --pretty=oneline -1 "$cmt" | sed -e 's/^[^ ]* //'
  77
  78         prev_head=`git rev-parse HEAD^0`
  79         # save the resulting commit so we can read-tree on it later
  80         echo "$prev_head" > "$dotest/prev_head"
  81
  82         # onto the next patch:
  83         msgnum=$(($msgnum + 1))
  84         echo "$msgnum" >"$dotest/msgnum"
  85 }
  86
  87 call_merge () {
  88         cmt="$(cat "$dotest/cmt.$1")"
  89         echo "$cmt" > "$dotest/current"
  90         hd=$(git rev-parse --verify HEAD)
  91         cmt_name=$(git symbolic-ref HEAD 2> /dev/null || echo HEAD)
  92         msgnum=$(cat "$dotest/msgnum")
  93         end=$(cat "$dotest/end")
  94         eval GITHEAD_$cmt='"${cmt_name##refs/heads/}~$(($end - $msgnum))"'
  95         eval GITHEAD_$hd='$(cat "$dotest/onto_name")'
  96         export GITHEAD_$cmt GITHEAD_$hd
  97         git-merge-$strategy "$cmt^" -- "$hd" "$cmt"
  98         rv=$?
  99         case "$rv" in
 100         0)
 101                 unset GITHEAD_$cmt GITHEAD_$hd
 102                 return
 103                 ;;
 104         1)
 105                 git rerere
 106                 die "$RESOLVEMSG"
 107                 ;;
 108         2)
 109                 echo "Strategy: $rv $strategy failed, try another" 1>&2
 110                 die "$RESOLVEMSG"
 111                 ;;
 112         *)
 113                 die "Unknown exit code ($rv) from command:" \
 114                         "git-merge-$strategy $cmt^ -- HEAD $cmt"
 115                 ;;
 116         esac
 117 }
 118
 119 move_to_original_branch () {
 120         test -z "$head_name" &&
 121                 head_name="$(cat "$dotest"/head-name)" &&
 122                 onto="$(cat "$dotest"/onto)" &&
 123                 orig_head="$(cat "$dotest"/orig-head)"
 124         case "$head_name" in
 125         refs/*)
 126                 message="rebase finished: $head_name onto $onto"
 127                 git update-ref -m "$message" \
 128                         $head_name $(git rev-parse HEAD) $orig_head &&
 129                 git symbolic-ref HEAD $head_name ||
 130                 die "Could not move back to $head_name"
 131                 ;;
 132         esac
 133 }
 134
 135 finish_rb_merge () {
 136         move_to_original_branch
 137         rm -r "$dotest"
 138         echo "All done."
 139 }
 140
 141 is_interactive () {
 142         test -f "$dotest"/interactive ||
 143         while :; do case $#,"$1" in 0,|*,-i|*,--interactive) break ;; esac
 144                 shift
 145         done && test -n "$1"
 146 }
 147
 148 is_interactive "$@" && exec git-rebase--interactive "$@"
 149
 150 while test $# != 0
 151 do
 152         case "$1" in
 153         --continue)
 154                 git diff-files --quiet || {
 155                         echo "You must edit all merge conflicts and then"
 156                         echo "mark them as resolved using git add"
 157                         exit 1
 158                 }
 159                 if test -d "$dotest"
 160                 then
 161                         prev_head=$(cat "$dotest/prev_head")
 162                         end=$(cat "$dotest/end")
 163                         msgnum=$(cat "$dotest/msgnum")
 164                         onto=$(cat "$dotest/onto")
 165                         continue_merge
 166                         while test "$msgnum" -le "$end"
 167                         do
 168                                 call_merge "$msgnum"
 169                                 continue_merge
 170                         done
 171                         finish_rb_merge
 172                         exit
 173                 fi
 174                 head_name=$(cat .dotest/head-name) &&
 175                 onto=$(cat .dotest/onto) &&
 176                 orig_head=$(cat .dotest/orig-head) &&
 177                 git am --resolved --3way --resolvemsg="$RESOLVEMSG" &&
 178                 move_to_original_branch
 179                 exit
 180                 ;;
 181         --skip)
 182                 git reset --hard HEAD || exit $?
 183                 if test -d "$dotest"
 184                 then
 185                         git rerere clear
 186                         prev_head=$(cat "$dotest/prev_head")
 187                         end=$(cat "$dotest/end")
 188                         msgnum=$(cat "$dotest/msgnum")
 189                         msgnum=$(($msgnum + 1))
 190                         onto=$(cat "$dotest/onto")
 191                         while test "$msgnum" -le "$end"
 192                         do
 193                                 call_merge "$msgnum"
 194                                 continue_merge
 195                         done
 196                         finish_rb_merge
 197                         exit
 198                 fi
 199                 head_name=$(cat .dotest/head-name) &&
 200                 onto=$(cat .dotest/onto) &&
 201                 orig_head=$(cat .dotest/orig-head) &&
 202                 git am -3 --skip --resolvemsg="$RESOLVEMSG" &&
 203                 move_to_original_branch
 204                 exit
 205                 ;;
 206         --abort)
 207                 git rerere clear
 208                 if test -d "$dotest"
 209                 then
 210                         move_to_original_branch
 211                 elif test -d .dotest
 212                 then
 213                         dotest=.dotest
 214                         move_to_original_branch
 215                 else
 216                         die "No rebase in progress?"
 217                 fi
 218                 git reset --hard $(cat $dotest/orig-head)
 219                 rm -r "$dotest"
 220                 exit
 221                 ;;
 222         --onto)
 223                 test 2 -le "$#" || usage
 224                 newbase="$2"
 225                 shift
 226                 ;;
 227         -M|-m|--m|--me|--mer|--merg|--merge)
 228                 do_merge=t
 229                 ;;
 230         -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
 231                 --strateg=*|--strategy=*|\
 232         -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
 233                 case "$#,$1" in
 234                 *,*=*)
 235                         strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
 236                 1,*)
 237                         usage ;;
 238                 *)
 239                         strategy="$2"
 240                         shift ;;
 241                 esac
 242                 do_merge=t
 243                 ;;
 244         -v|--verbose)
 245                 verbose=t
 246                 ;;
 247         --whitespace=*)
 248                 git_am_opt="$git_am_opt $1"
 249                 ;;
 250         -C*)
 251                 git_am_opt="$git_am_opt $1"
 252                 ;;
 253         -*)
 254                 usage
 255                 ;;
 256         *)
 257                 break
 258                 ;;
 259         esac
 260         shift
 261 done
 262
 263 # Make sure we do not have .dotest
 264 if test -z "$do_merge"
 265 then
 266         if mkdir .dotest
 267         then
 268                 rmdir .dotest
 269         else
 270                 echo >&2 '
 271 It seems that I cannot create a .dotest directory, and I wonder if you
 272 are in the middle of patch application or another rebase.  If that is not
 273 the case, please rm -fr .dotest and run me again.  I am stopping in case
 274 you still have something valuable there.'
 275                 exit 1
 276         fi
 277 else
 278         if test -d "$dotest"
 279         then
 280                 die "previous dotest directory $dotest still exists." \
 281                         'try git-rebase < --continue | --abort >'
 282         fi
 283 fi
 284
 285 # The tree must be really really clean.
 286 git update-index --refresh || exit
 287 diff=$(git diff-index --cached --name-status -r HEAD --)
 288 case "$diff" in
 289 ?*)     echo "cannot rebase: your index is not up-to-date"
 290         echo "$diff"
 291         exit 1
 292         ;;
 293 esac
 294
 295 # The upstream head must be given.  Make sure it is valid.
 296 upstream_name="$1"
 297 upstream=`git rev-parse --verify "${upstream_name}^0"` ||
 298     die "invalid upstream $upstream_name"
 299
 300 # Make sure the branch to rebase onto is valid.
 301 onto_name=${newbase-"$upstream_name"}
 302 onto=$(git rev-parse --verify "${onto_name}^0") || exit
 303
 304 # If a hook exists, give it a chance to interrupt
 305 if test -x "$GIT_DIR/hooks/pre-rebase"
 306 then
 307         "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} || {
 308                 echo >&2 "The pre-rebase hook refused to rebase."
 309                 exit 1
 310         }
 311 fi
 312
 313 # If the branch to rebase is given, first switch to it.
 314 case "$#" in
 315 2)
 316         branch_name="$2"
 317         git-checkout "$2" || usage
 318         ;;
 319 *)
 320         if branch_name=`git symbolic-ref -q HEAD`
 321         then
 322                 branch_name=`expr "z$branch_name" : 'zrefs/heads/\(.*\)'`
 323         else
 324                 branch_name=HEAD ;# detached
 325         fi
 326         ;;
 327 esac
 328 branch=$(git rev-parse --verify "${branch_name}^0") || exit
 329
 330 # Now we are rebasing commits $upstream..$branch on top of $onto
 331
 332 # Check if we are already based on $onto with linear history,
 333 # but this should be done only when upstream and onto are the same.
 334 mb=$(git merge-base "$onto" "$branch")
 335 if test "$upstream" = "$onto" && test "$mb" = "$onto" &&
 336         # linear history?
 337         ! git rev-list --parents "$onto".."$branch" | grep " .* " > /dev/null
 338 then
 339         echo >&2 "Current branch $branch_name is up to date."
 340         exit 0
 341 fi
 342
 343 if test -n "$verbose"
 344 then
 345         echo "Changes from $mb to $onto:"
 346         # We want color (if set), but no pager
 347         GIT_PAGER='' git diff --stat --summary "$mb" "$onto"
 348 fi
 349
 350 # move to a detached HEAD
 351 orig_head=$(git rev-parse HEAD^0)
 352 head_name=$(git symbolic-ref HEAD 2> /dev/null)
 353 case "$head_name" in
 354 '')
 355         head_name="detached HEAD"
 356         ;;
 357 *)
 358         git checkout "$orig_head" > /dev/null 2>&1 ||
 359                 die "could not detach HEAD"
 360         ;;
 361 esac
 362
 363 # Rewind the head to "$onto"; this saves our current head in ORIG_HEAD.
 364 echo "First, rewinding head to replay your work on top of it..."
 365 git-reset --hard "$onto"
 366
 367 # If the $onto is a proper descendant of the tip of the branch, then
 368 # we just fast forwarded.
 369 if test "$mb" = "$branch"
 370 then
 371         echo >&2 "Fast-forwarded $branch_name to $onto_name."
 372         move_to_original_branch
 373         exit 0
 374 fi
 375
 376 if test -z "$do_merge"
 377 then
 378         git format-patch -k --stdout --full-index --ignore-if-in-upstream "$upstream"..ORIG_HEAD |
 379         git am $git_am_opt --binary -3 -k --resolvemsg="$RESOLVEMSG" &&
 380         move_to_original_branch
 381         ret=$?
 382         test 0 != $ret -a -d .dotest &&
 383                 echo $head_name > .dotest/head-name &&
 384                 echo $onto > .dotest/onto &&
 385                 echo $orig_head > .dotest/orig-head
 386         exit $ret
 387 fi
 388
 389 # start doing a rebase with git-merge
 390 # this is rename-aware if the recursive (default) strategy is used
 391
 392 mkdir -p "$dotest"
 393 echo "$onto" > "$dotest/onto"
 394 echo "$onto_name" > "$dotest/onto_name"
 395 prev_head=$orig_head
 396 echo "$prev_head" > "$dotest/prev_head"
 397 echo "$orig_head" > "$dotest/orig-head"
 398 echo "$head_name" > "$dotest/head-name"
 399
 400 msgnum=0
 401 for cmt in `git rev-list --reverse --no-merges "$upstream"..ORIG_HEAD`
 402 do
 403         msgnum=$(($msgnum + 1))
 404         echo "$cmt" > "$dotest/cmt.$msgnum"
 405 done
 406
 407 echo 1 >"$dotest/msgnum"
 408 echo $msgnum >"$dotest/end"
 409
 410 end=$msgnum
 411 msgnum=1
 412
 413 while test "$msgnum" -le "$end"
 414 do
 415         call_merge "$msgnum"
 416         continue_merge
 417 done
 418
 419 finish_rb_merge