Andrew's git - gitweb.git/blob

   1#!/bin/sh
   2#
   3# Copyright (c) 2005 Junio C Hamano
   4#
   5
   6USAGE='[-n] [--no-commit] [--squash] [-s <strategy>]... <merge-message> <head> <remote>+'
   7. git-sh-setup
   8
   9LF='
  10'
  11
  12all_strategies='recursive recur octopus resolve stupid ours'
  13case "${GIT_USE_RECUR_FOR_RECURSIVE}" in
  14'')
  15        default_twohead_strategies=recursive ;;
  16?*)
  17        default_twohead_strategies=recur ;;
  18esac
  19default_octopus_strategies='octopus'
  20no_trivial_merge_strategies='ours'
  21use_strategies=
  22
  23index_merge=t
  24if test "@@NO_PYTHON@@"; then
  25        all_strategies='recur resolve octopus stupid ours'
  26        default_twohead_strategies='resolve'
  27fi
  28
  29dropsave() {
  30        rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
  31                 "$GIT_DIR/MERGE_SAVE" || exit 1
  32}
  33
  34savestate() {
  35        # Stash away any local modifications.
  36        git-diff-index -z --name-only $head |
  37        cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
  38}
  39
  40restorestate() {
  41        if test -f "$GIT_DIR/MERGE_SAVE"
  42        then
  43                git reset --hard $head
  44                cpio -iuv <"$GIT_DIR/MERGE_SAVE"
  45                git-update-index --refresh >/dev/null
  46        fi
  47}
  48
  49finish_up_to_date () {
  50        case "$squash" in
  51        t)
  52                echo "$1 (nothing to squash)" ;;
  53        '')
  54                echo "$1" ;;
  55        esac
  56        dropsave
  57}
  58
  59squash_message () {
  60        echo Squashed commit of the following:
  61        echo
  62        git-log --no-merges ^"$head" $remote
  63}
  64
  65finish () {
  66        test '' = "$2" || echo "$2"
  67        case "$squash" in
  68        t)
  69                echo "Squash commit -- not updating HEAD"
  70                squash_message >"$GIT_DIR/SQUASH_MSG"
  71                ;;
  72        '')
  73                case "$merge_msg" in
  74                '')
  75                        echo "No merge message -- not updating HEAD"
  76                        ;;
  77                *)
  78                        git-update-ref HEAD "$1" "$head" || exit 1
  79                        ;;
  80                esac
  81                ;;
  82        esac
  83        case "$1" in
  84        '')
  85                ;;
  86        ?*)
  87                case "$no_summary" in
  88                '')
  89                        git-diff-tree --stat --summary -M "$head" "$1"
  90                        ;;
  91                esac
  92                ;;
  93        esac
  94}
  95
  96while case "$#" in 0) break ;; esac
  97do
  98        case "$1" in
  99        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
 100                --no-summa|--no-summar|--no-summary)
 101                no_summary=t ;;
 102        --sq|--squ|--squa|--squas|--squash)
 103                squash=t no_commit=t ;;
 104        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
 105                no_commit=t ;;
 106        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
 107                --strateg=*|--strategy=*|\
 108        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
 109                case "$#,$1" in
 110                *,*=*)
 111                        strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
 112                1,*)
 113                        usage ;;
 114                *)
 115                        strategy="$2"
 116                        shift ;;
 117                esac
 118                case "$strategy,${GIT_USE_RECUR_FOR_RECURSIVE}" in
 119                recursive,?*)
 120                        strategy=recur ;;
 121                esac
 122                case " $all_strategies " in
 123                *" $strategy "*)
 124                        use_strategies="$use_strategies$strategy " ;;
 125                *)
 126                        die "available strategies are: $all_strategies" ;;
 127                esac
 128                ;;
 129        -*)     usage ;;
 130        *)      break ;;
 131        esac
 132        shift
 133done
 134
 135merge_msg="$1"
 136shift
 137head_arg="$1"
 138head=$(git-rev-parse --verify "$1"^0) || usage
 139shift
 140
 141# All the rest are remote heads
 142test "$#" = 0 && usage ;# we need at least one remote head.
 143
 144remoteheads=
 145for remote
 146do
 147        remotehead=$(git-rev-parse --verify "$remote"^0) ||
 148            die "$remote - not something we can merge"
 149        remoteheads="${remoteheads}$remotehead "
 150done
 151set x $remoteheads ; shift
 152
 153case "$use_strategies" in
 154'')
 155        case "$#" in
 156        1)
 157                use_strategies="$default_twohead_strategies" ;;
 158        *)
 159                use_strategies="$default_octopus_strategies" ;;
 160        esac
 161        ;;
 162esac
 163
 164for s in $use_strategies
 165do
 166        case " $s " in
 167        *" $no_trivial_merge_strategies "*)
 168                index_merge=f
 169                break
 170                ;;
 171        esac
 172done
 173
 174case "$#" in
 1751)
 176        common=$(git-merge-base --all $head "$@")
 177        ;;
 178*)
 179        common=$(git-show-branch --merge-base $head "$@")
 180        ;;
 181esac
 182echo "$head" >"$GIT_DIR/ORIG_HEAD"
 183
 184case "$index_merge,$#,$common,$no_commit" in
 185f,*)
 186        # We've been told not to try anything clever.  Skip to real merge.
 187        ;;
 188?,*,'',*)
 189        # No common ancestors found. We need a real merge.
 190        ;;
 191?,1,"$1",*)
 192        # If head can reach all the merge then we are up to date.
 193        # but first the most common case of merging one remote.
 194        finish_up_to_date "Already up-to-date."
 195        exit 0
 196        ;;
 197?,1,"$head",*)
 198        # Again the most common case of merging one remote.
 199        echo "Updating from $head to $1"
 200        git-update-index --refresh 2>/dev/null
 201        new_head=$(git-rev-parse --verify "$1^0") &&
 202        git-read-tree -u -v -m $head "$new_head" &&
 203        finish "$new_head" "Fast forward"
 204        dropsave
 205        exit 0
 206        ;;
 207?,1,?*"$LF"?*,*)
 208        # We are not doing octopus and not fast forward.  Need a
 209        # real merge.
 210        ;;
 211?,1,*,)
 212        # We are not doing octopus, not fast forward, and have only
 213        # one common.  See if it is really trivial.
 214        git var GIT_COMMITTER_IDENT >/dev/null || exit
 215
 216        echo "Trying really trivial in-index merge..."
 217        git-update-index --refresh 2>/dev/null
 218        if git-read-tree --trivial -m -u -v $common $head "$1" &&
 219           result_tree=$(git-write-tree)
 220        then
 221            echo "Wonderful."
 222            result_commit=$(
 223                echo "$merge_msg" |
 224                git-commit-tree $result_tree -p HEAD -p "$1"
 225            ) || exit
 226            finish "$result_commit" "In-index merge"
 227            dropsave
 228            exit 0
 229        fi
 230        echo "Nope."
 231        ;;
 232*)
 233        # An octopus.  If we can reach all the remote we are up to date.
 234        up_to_date=t
 235        for remote
 236        do
 237                common_one=$(git-merge-base --all $head $remote)
 238                if test "$common_one" != "$remote"
 239                then
 240                        up_to_date=f
 241                        break
 242                fi
 243        done
 244        if test "$up_to_date" = t
 245        then
 246                finish_up_to_date "Already up-to-date. Yeeah!"
 247                exit 0
 248        fi
 249        ;;
 250esac
 251
 252# We are going to make a new commit.
 253git var GIT_COMMITTER_IDENT >/dev/null || exit
 254
 255# At this point, we need a real merge.  No matter what strategy
 256# we use, it would operate on the index, possibly affecting the
 257# working tree, and when resolved cleanly, have the desired tree
 258# in the index -- this means that the index must be in sync with
 259# the $head commit.  The strategies are responsible to ensure this.
 260
 261case "$use_strategies" in
 262?*' '?*)
 263    # Stash away the local changes so that we can try more than one.
 264    savestate
 265    single_strategy=no
 266    ;;
 267*)
 268    rm -f "$GIT_DIR/MERGE_SAVE"
 269    single_strategy=yes
 270    ;;
 271esac
 272
 273result_tree= best_cnt=-1 best_strategy= wt_strategy=
 274merge_was_ok=
 275for strategy in $use_strategies
 276do
 277    test "$wt_strategy" = '' || {
 278        echo "Rewinding the tree to pristine..."
 279        restorestate
 280    }
 281    case "$single_strategy" in
 282    no)
 283        echo "Trying merge strategy $strategy..."
 284        ;;
 285    esac
 286
 287    # Remember which strategy left the state in the working tree
 288    wt_strategy=$strategy
 289
 290    git-merge-$strategy $common -- "$head_arg" "$@"
 291    exit=$?
 292    if test "$no_commit" = t && test "$exit" = 0
 293    then
 294        merge_was_ok=t
 295        exit=1 ;# pretend it left conflicts.
 296    fi
 297
 298    test "$exit" = 0 || {
 299
 300        # The backend exits with 1 when conflicts are left to be resolved,
 301        # with 2 when it does not handle the given merge at all.
 302
 303        if test "$exit" -eq 1
 304        then
 305            cnt=`{
 306                git-diff-files --name-only
 307                git-ls-files --unmerged
 308            } | wc -l`
 309            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 310            then
 311                best_strategy=$strategy
 312                best_cnt=$cnt
 313            fi
 314        fi
 315        continue
 316    }
 317
 318    # Automerge succeeded.
 319    result_tree=$(git-write-tree) && break
 320done
 321
 322# If we have a resulting tree, that means the strategy module
 323# auto resolved the merge cleanly.
 324if test '' != "$result_tree"
 325then
 326    parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
 327    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 328    finish "$result_commit" "Merge $result_commit, made by $wt_strategy."
 329    dropsave
 330    exit 0
 331fi
 332
 333# Pick the result from the best strategy and have the user fix it up.
 334case "$best_strategy" in
 335'')
 336        restorestate
 337        echo >&2 "No merge strategy handled the merge."
 338        exit 2
 339        ;;
 340"$wt_strategy")
 341        # We already have its result in the working tree.
 342        ;;
 343*)
 344        echo "Rewinding the tree to pristine..."
 345        restorestate
 346        echo "Using the $best_strategy to prepare resolving by hand."
 347        git-merge-$best_strategy $common -- "$head_arg" "$@"
 348        ;;
 349esac
 350
 351if test "$squash" = t
 352then
 353        finish
 354else
 355        for remote
 356        do
 357                echo $remote
 358        done >"$GIT_DIR/MERGE_HEAD"
 359        echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 360fi
 361
 362if test "$merge_was_ok" = t
 363then
 364        echo >&2 \
 365        "Automatic merge went well; stopped before committing as requested"
 366        exit 0
 367else
 368        {
 369            echo '
 370Conflicts:
 371'
 372                git ls-files --unmerged |
 373                sed -e 's/^[^   ]*      /       /' |
 374                uniq
 375        } >>"$GIT_DIR/MERGE_MSG"
 376        if test -d "$GIT_DIR/rr-cache"
 377        then
 378                git-rerere
 379        fi
 380        die "Automatic merge failed; fix conflicts and then commit the result."
 381fi