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.
  22
  23 Example:       git-rebase master~1 topic
  24
  25         A---B---C topic                   A'\''--B'\''--C'\'' topic
  26        /                   -->           /
  27   D---E---F---G master          D---E---F---G master
  28 '
  29
  30 SUBDIRECTORY_OK=Yes
  31 OPTIONS_SPEC=
  32 . git-sh-setup
  33 set_reflog_action rebase
  34 require_work_tree
  35 cd_to_toplevel
  36
  37 RESOLVEMSG="
  38 When you have resolved this problem run \"git rebase --continue\".
  39 If you would prefer to skip this patch, instead run \"git rebase --skip\".
  40 To restore the original branch and stop rebasing run \"git rebase --abort\".
  41 "
  42 unset newbase
  43 strategy=recursive
  44 do_merge=
  45 dotest=$GIT_DIR/.dotest-merge
  46 prec=4
  47 verbose=
  48 git_am_opt=
  49
  50 continue_merge () {
  51         test -n "$prev_head" || die "prev_head must be defined"
  52         test -d "$dotest" || die "$dotest directory does not exist"
  53
  54         unmerged=$(git ls-files -u)
  55         if test -n "$unmerged"
  56         then
  57                 echo "You still have unmerged paths in your index"
  58                 echo "did you forget to use git add?"
  59                 die "$RESOLVEMSG"
  60         fi
  61
  62         cmt=`cat "$dotest/current"`
  63         if ! git diff-index --quiet --ignore-submodules HEAD --
  64         then
  65                 if ! git commit --no-verify -C "$cmt"
  66                 then
  67                         echo "Commit failed, please do not call \"git commit\""
  68                         echo "directly, but instead do one of the following: "
  69                         die "$RESOLVEMSG"
  70                 fi
  71                 printf "Committed: %0${prec}d " $msgnum
  72         else
  73                 printf "Already applied: %0${prec}d " $msgnum
  74         fi
  75         git rev-list --pretty=oneline -1 "$cmt" | sed -e 's/^[^ ]* //'
  76
  77         prev_head=`git rev-parse HEAD^0`
  78         # save the resulting commit so we can read-tree on it later
  79         echo "$prev_head" > "$dotest/prev_head"
  80
  81         # onto the next patch:
  82         msgnum=$(($msgnum + 1))
  83         echo "$msgnum" >"$dotest/msgnum"
  84 }
  85
  86 call_merge () {
  87         cmt="$(cat "$dotest/cmt.$1")"
  88         echo "$cmt" > "$dotest/current"
  89         hd=$(git rev-parse --verify HEAD)
  90         cmt_name=$(git symbolic-ref HEAD 2> /dev/null || echo HEAD)
  91         msgnum=$(cat "$dotest/msgnum")
  92         end=$(cat "$dotest/end")
  93         eval GITHEAD_$cmt='"${cmt_name##refs/heads/}~$(($end - $msgnum))"'
  94         eval GITHEAD_$hd='$(cat "$dotest/onto_name")'
  95         export GITHEAD_$cmt GITHEAD_$hd
  96         git-merge-$strategy "$cmt^" -- "$hd" "$cmt"
  97         rv=$?
  98         case "$rv" in
  99         0)
 100                 unset GITHEAD_$cmt GITHEAD_$hd
 101                 return
 102                 ;;
 103         1)
 104                 git rerere
 105                 die "$RESOLVEMSG"
 106                 ;;
 107         2)
 108                 echo "Strategy: $rv $strategy failed, try another" 1>&2
 109                 die "$RESOLVEMSG"
 110                 ;;
 111         *)
 112                 die "Unknown exit code ($rv) from command:" \
 113                         "git-merge-$strategy $cmt^ -- HEAD $cmt"
 114                 ;;
 115         esac
 116 }
 117
 118 move_to_original_branch () {
 119         test -z "$head_name" &&
 120                 head_name="$(cat "$dotest"/head-name)" &&
 121                 onto="$(cat "$dotest"/onto)" &&
 122                 orig_head="$(cat "$dotest"/orig-head)"
 123         case "$head_name" in
 124         refs/*)
 125                 message="rebase finished: $head_name onto $onto"
 126                 git update-ref -m "$message" \
 127                         $head_name $(git rev-parse HEAD) $orig_head &&
 128                 git symbolic-ref HEAD $head_name ||
 129                 die "Could not move back to $head_name"
 130                 ;;
 131         esac
 132 }
 133
 134 finish_rb_merge () {
 135         move_to_original_branch
 136         rm -r "$dotest"
 137         echo "All done."
 138 }
 139
 140 is_interactive () {
 141         test -f "$dotest"/interactive ||
 142         while :; do case $#,"$1" in 0,|*,-i|*,--interactive) break ;; esac
 143                 shift
 144         done && test -n "$1"
 145 }
 146
 147 is_interactive "$@" && exec git-rebase--interactive "$@"
 148
 149 while test $# != 0
 150 do
 151         case "$1" in
 152         --continue)
 153                 git diff-files --quiet --ignore-submodules || {
 154                         echo "You must edit all merge conflicts and then"
 155                         echo "mark them as resolved using git add"
 156                         exit 1
 157                 }
 158                 if test -d "$dotest"
 159                 then
 160                         prev_head=$(cat "$dotest/prev_head")
 161                         end=$(cat "$dotest/end")
 162                         msgnum=$(cat "$dotest/msgnum")
 163                         onto=$(cat "$dotest/onto")
 164                         continue_merge
 165                         while test "$msgnum" -le "$end"
 166                         do
 167                                 call_merge "$msgnum"
 168                                 continue_merge
 169                         done
 170                         finish_rb_merge
 171                         exit
 172                 fi
 173                 head_name=$(cat .dotest/head-name) &&
 174                 onto=$(cat .dotest/onto) &&
 175                 orig_head=$(cat .dotest/orig-head) &&
 176                 git am --resolved --3way --resolvemsg="$RESOLVEMSG" &&
 177                 move_to_original_branch
 178                 exit
 179                 ;;
 180         --skip)
 181                 git reset --hard HEAD || exit $?
 182                 if test -d "$dotest"
 183                 then
 184                         git rerere clear
 185                         prev_head=$(cat "$dotest/prev_head")
 186                         end=$(cat "$dotest/end")
 187                         msgnum=$(cat "$dotest/msgnum")
 188                         msgnum=$(($msgnum + 1))
 189                         onto=$(cat "$dotest/onto")
 190                         while test "$msgnum" -le "$end"
 191                         do
 192                                 call_merge "$msgnum"
 193                                 continue_merge
 194                         done
 195                         finish_rb_merge
 196                         exit
 197                 fi
 198                 head_name=$(cat .dotest/head-name) &&
 199                 onto=$(cat .dotest/onto) &&
 200                 orig_head=$(cat .dotest/orig-head) &&
 201                 git am -3 --skip --resolvemsg="$RESOLVEMSG" &&
 202                 move_to_original_branch
 203                 exit
 204                 ;;
 205         --abort)
 206                 git rerere clear
 207                 if test -d "$dotest"
 208                 then
 209                         move_to_original_branch
 210                 elif test -d .dotest
 211                 then
 212                         dotest=.dotest
 213                         move_to_original_branch
 214                 else
 215                         die "No rebase in progress?"
 216                 fi
 217                 git reset --hard $(cat "$dotest/orig-head")
 218                 rm -r "$dotest"
 219                 exit
 220                 ;;
 221         --onto)
 222                 test 2 -le "$#" || usage
 223                 newbase="$2"
 224                 shift
 225                 ;;
 226         -M|-m|--m|--me|--mer|--merg|--merge)
 227                 do_merge=t
 228                 ;;
 229         -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
 230                 --strateg=*|--strategy=*|\
 231         -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
 232                 case "$#,$1" in
 233                 *,*=*)
 234                         strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
 235                 1,*)
 236                         usage ;;
 237                 *)
 238                         strategy="$2"
 239                         shift ;;
 240                 esac
 241                 do_merge=t
 242                 ;;
 243         -v|--verbose)
 244                 verbose=t
 245                 ;;
 246         --whitespace=*)
 247                 git_am_opt="$git_am_opt $1"
 248                 ;;
 249         -C*)
 250                 git_am_opt="$git_am_opt $1"
 251                 ;;
 252         -*)
 253                 usage
 254                 ;;
 255         *)
 256                 break
 257                 ;;
 258         esac
 259         shift
 260 done
 261
 262 # Make sure we do not have .dotest
 263 if test -z "$do_merge"
 264 then
 265         if mkdir .dotest
 266         then
 267                 rmdir .dotest
 268         else
 269                 echo >&2 '
 270 It seems that I cannot create a .dotest directory, and I wonder if you
 271 are in the middle of patch application or another rebase.  If that is not
 272 the case, please rm -fr .dotest and run me again.  I am stopping in case
 273 you still have something valuable there.'
 274                 exit 1
 275         fi
 276 else
 277         if test -d "$dotest"
 278         then
 279                 die "previous dotest directory $dotest still exists." \
 280                         'try git-rebase < --continue | --abort >'
 281         fi
 282 fi
 283
 284 # The tree must be really really clean.
 285 git update-index --ignore-submodules --refresh || exit
 286 diff=$(git diff-index --cached --name-status -r --ignore-submodules HEAD --)
 287 case "$diff" in
 288 ?*)     echo "cannot rebase: your index is not up-to-date"
 289         echo "$diff"
 290         exit 1
 291         ;;
 292 esac
 293
 294 # The upstream head must be given.  Make sure it is valid.
 295 upstream_name="$1"
 296 upstream=`git rev-parse --verify "${upstream_name}^0"` ||
 297     die "invalid upstream $upstream_name"
 298
 299 # Make sure the branch to rebase onto is valid.
 300 onto_name=${newbase-"$upstream_name"}
 301 onto=$(git rev-parse --verify "${onto_name}^0") || exit
 302
 303 # If a hook exists, give it a chance to interrupt
 304 if test -x "$GIT_DIR/hooks/pre-rebase"
 305 then
 306         "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} || {
 307                 echo >&2 "The pre-rebase hook refused to rebase."
 308                 exit 1
 309         }
 310 fi
 311
 312 # If the branch to rebase is given, that is the branch we will rebase
 313 # $branch_name -- branch being rebased, or HEAD (already detached)
 314 # $orig_head -- commit object name of tip of the branch before rebasing
 315 # $head_name -- refs/heads/<that-branch> or "detached HEAD"
 316 switch_to=
 317 case "$#" in
 318 2)
 319         # Is it "rebase other $branchname" or "rebase other $commit"?
 320         branch_name="$2"
 321         switch_to="$2"
 322
 323         if git show-ref --verify --quiet -- "refs/heads/$2" &&
 324            branch=$(git rev-parse --verify "refs/heads/$2" 2>/dev/null)
 325         then
 326                 head_name="refs/heads/$2"
 327         elif branch=$(git rev-parse --verify "$2" 2>/dev/null)
 328         then
 329                 head_name="detached HEAD"
 330         else
 331                 usage
 332         fi
 333         ;;
 334 *)
 335         # Do not need to switch branches, we are already on it.
 336         if branch_name=`git symbolic-ref -q HEAD`
 337         then
 338                 head_name=$branch_name
 339                 branch_name=`expr "z$branch_name" : 'zrefs/heads/\(.*\)'`
 340         else
 341                 head_name="detached HEAD"
 342                 branch_name=HEAD ;# detached
 343         fi
 344         branch=$(git rev-parse --verify "${branch_name}^0") || exit
 345         ;;
 346 esac
 347 orig_head=$branch
 348
 349 # Now we are rebasing commits $upstream..$branch on top of $onto
 350
 351 # Check if we are already based on $onto with linear history,
 352 # but this should be done only when upstream and onto are the same.
 353 mb=$(git merge-base "$onto" "$branch")
 354 if test "$upstream" = "$onto" && test "$mb" = "$onto" &&
 355         # linear history?
 356         ! (git rev-list --parents "$onto".."$branch" | grep " .* ") > /dev/null
 357 then
 358         # Lazily switch to the target branch if needed...
 359         test -z "$switch_to" || git checkout "$switch_to"
 360         echo >&2 "Current branch $branch_name is up to date."
 361         exit 0
 362 fi
 363
 364 if test -n "$verbose"
 365 then
 366         echo "Changes from $mb to $onto:"
 367         # We want color (if set), but no pager
 368         GIT_PAGER='' git diff --stat --summary "$mb" "$onto"
 369 fi
 370
 371 # Detach HEAD and reset the tree
 372 echo "First, rewinding head to replay your work on top of it..."
 373 git checkout "$onto^0" >/dev/null 2>&1 ||
 374         die "could not detach HEAD"
 375 # git reset --hard "$onto^0"
 376
 377 # If the $onto is a proper descendant of the tip of the branch, then
 378 # we just fast forwarded.
 379 if test "$mb" = "$branch"
 380 then
 381         echo >&2 "Fast-forwarded $branch_name to $onto_name."
 382         move_to_original_branch
 383         exit 0
 384 fi
 385
 386 if test -z "$do_merge"
 387 then
 388         git format-patch -k --stdout --full-index --ignore-if-in-upstream \
 389                 "$upstream..$orig_head" |
 390         git am $git_am_opt --rebasing --resolvemsg="$RESOLVEMSG" &&
 391         move_to_original_branch
 392         ret=$?
 393         test 0 != $ret -a -d .dotest &&
 394                 echo $head_name > .dotest/head-name &&
 395                 echo $onto > .dotest/onto &&
 396                 echo $orig_head > .dotest/orig-head
 397         exit $ret
 398 fi
 399
 400 # start doing a rebase with git-merge
 401 # this is rename-aware if the recursive (default) strategy is used
 402
 403 mkdir -p "$dotest"
 404 echo "$onto" > "$dotest/onto"
 405 echo "$onto_name" > "$dotest/onto_name"
 406 prev_head=$orig_head
 407 echo "$prev_head" > "$dotest/prev_head"
 408 echo "$orig_head" > "$dotest/orig-head"
 409 echo "$head_name" > "$dotest/head-name"
 410
 411 msgnum=0
 412 for cmt in `git rev-list --reverse --no-merges "$upstream..$orig_head"`
 413 do
 414         msgnum=$(($msgnum + 1))
 415         echo "$cmt" > "$dotest/cmt.$msgnum"
 416 done
 417
 418 echo 1 >"$dotest/msgnum"
 419 echo $msgnum >"$dotest/end"
 420
 421 end=$msgnum
 422 msgnum=1
 423
 424 while test "$msgnum" -le "$end"
 425 do
 426         call_merge "$msgnum"
 427         continue_merge
 428 done
 429
 430 finish_rb_merge