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        if test '' = "$2"
  67        then
  68                rlogm="$rloga"
  69        else
  70                echo "$2"
  71                rlogm="$rloga: $2"
  72        fi
  73        case "$squash" in
  74        t)
  75                echo "Squash commit -- not updating HEAD"
  76                squash_message >"$GIT_DIR/SQUASH_MSG"
  77                ;;
  78        '')
  79                case "$merge_msg" in
  80                '')
  81                        echo "No merge message -- not updating HEAD"
  82                        ;;
  83                *)
  84                        git-update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1
  85                        ;;
  86                esac
  87                ;;
  88        esac
  89        case "$1" in
  90        '')
  91                ;;
  92        ?*)
  93                case "$no_summary" in
  94                '')
  95                        git-diff-tree --stat --summary -M "$head" "$1"
  96                        ;;
  97                esac
  98                ;;
  99        esac
 100}
 101
 102rloga=
 103while case "$#" in 0) break ;; esac
 104do
 105        case "$1" in
 106        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
 107                --no-summa|--no-summar|--no-summary)
 108                no_summary=t ;;
 109        --sq|--squ|--squa|--squas|--squash)
 110                squash=t no_commit=t ;;
 111        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
 112                no_commit=t ;;
 113        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
 114                --strateg=*|--strategy=*|\
 115        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
 116                case "$#,$1" in
 117                *,*=*)
 118                        strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
 119                1,*)
 120                        usage ;;
 121                *)
 122                        strategy="$2"
 123                        shift ;;
 124                esac
 125                case "$strategy,${GIT_USE_RECUR_FOR_RECURSIVE}" in
 126                recursive,?*)
 127                        strategy=recur ;;
 128                esac
 129                case " $all_strategies " in
 130                *" $strategy "*)
 131                        use_strategies="$use_strategies$strategy " ;;
 132                *)
 133                        die "available strategies are: $all_strategies" ;;
 134                esac
 135                ;;
 136        --reflog-action=*)
 137                rloga=`expr "z$1" : 'z-[^=]*=\(.*\)'`
 138                ;;
 139        -*)     usage ;;
 140        *)      break ;;
 141        esac
 142        shift
 143done
 144
 145merge_msg="$1"
 146shift
 147head_arg="$1"
 148head=$(git-rev-parse --verify "$1"^0) || usage
 149shift
 150
 151# All the rest are remote heads
 152test "$#" = 0 && usage ;# we need at least one remote head.
 153test "$rloga" = '' && rloga="merge: $@"
 154
 155remoteheads=
 156for remote
 157do
 158        remotehead=$(git-rev-parse --verify "$remote"^0) ||
 159            die "$remote - not something we can merge"
 160        remoteheads="${remoteheads}$remotehead "
 161done
 162set x $remoteheads ; shift
 163
 164case "$use_strategies" in
 165'')
 166        case "$#" in
 167        1)
 168                use_strategies="$default_twohead_strategies" ;;
 169        *)
 170                use_strategies="$default_octopus_strategies" ;;
 171        esac
 172        ;;
 173esac
 174
 175for s in $use_strategies
 176do
 177        case " $s " in
 178        *" $no_trivial_merge_strategies "*)
 179                index_merge=f
 180                break
 181                ;;
 182        esac
 183done
 184
 185case "$#" in
 1861)
 187        common=$(git-merge-base --all $head "$@")
 188        ;;
 189*)
 190        common=$(git-show-branch --merge-base $head "$@")
 191        ;;
 192esac
 193echo "$head" >"$GIT_DIR/ORIG_HEAD"
 194
 195case "$index_merge,$#,$common,$no_commit" in
 196f,*)
 197        # We've been told not to try anything clever.  Skip to real merge.
 198        ;;
 199?,*,'',*)
 200        # No common ancestors found. We need a real merge.
 201        ;;
 202?,1,"$1",*)
 203        # If head can reach all the merge then we are up to date.
 204        # but first the most common case of merging one remote.
 205        finish_up_to_date "Already up-to-date."
 206        exit 0
 207        ;;
 208?,1,"$head",*)
 209        # Again the most common case of merging one remote.
 210        echo "Updating from $head to $1"
 211        git-update-index --refresh 2>/dev/null
 212        new_head=$(git-rev-parse --verify "$1^0") &&
 213        git-read-tree -u -v -m $head "$new_head" &&
 214        finish "$new_head" "Fast forward"
 215        dropsave
 216        exit 0
 217        ;;
 218?,1,?*"$LF"?*,*)
 219        # We are not doing octopus and not fast forward.  Need a
 220        # real merge.
 221        ;;
 222?,1,*,)
 223        # We are not doing octopus, not fast forward, and have only
 224        # one common.  See if it is really trivial.
 225        git var GIT_COMMITTER_IDENT >/dev/null || exit
 226
 227        echo "Trying really trivial in-index merge..."
 228        git-update-index --refresh 2>/dev/null
 229        if git-read-tree --trivial -m -u -v $common $head "$1" &&
 230           result_tree=$(git-write-tree)
 231        then
 232            echo "Wonderful."
 233            result_commit=$(
 234                echo "$merge_msg" |
 235                git-commit-tree $result_tree -p HEAD -p "$1"
 236            ) || exit
 237            finish "$result_commit" "In-index merge"
 238            dropsave
 239            exit 0
 240        fi
 241        echo "Nope."
 242        ;;
 243*)
 244        # An octopus.  If we can reach all the remote we are up to date.
 245        up_to_date=t
 246        for remote
 247        do
 248                common_one=$(git-merge-base --all $head $remote)
 249                if test "$common_one" != "$remote"
 250                then
 251                        up_to_date=f
 252                        break
 253                fi
 254        done
 255        if test "$up_to_date" = t
 256        then
 257                finish_up_to_date "Already up-to-date. Yeeah!"
 258                exit 0
 259        fi
 260        ;;
 261esac
 262
 263# We are going to make a new commit.
 264git var GIT_COMMITTER_IDENT >/dev/null || exit
 265
 266# At this point, we need a real merge.  No matter what strategy
 267# we use, it would operate on the index, possibly affecting the
 268# working tree, and when resolved cleanly, have the desired tree
 269# in the index -- this means that the index must be in sync with
 270# the $head commit.  The strategies are responsible to ensure this.
 271
 272case "$use_strategies" in
 273?*' '?*)
 274    # Stash away the local changes so that we can try more than one.
 275    savestate
 276    single_strategy=no
 277    ;;
 278*)
 279    rm -f "$GIT_DIR/MERGE_SAVE"
 280    single_strategy=yes
 281    ;;
 282esac
 283
 284result_tree= best_cnt=-1 best_strategy= wt_strategy=
 285merge_was_ok=
 286for strategy in $use_strategies
 287do
 288    test "$wt_strategy" = '' || {
 289        echo "Rewinding the tree to pristine..."
 290        restorestate
 291    }
 292    case "$single_strategy" in
 293    no)
 294        echo "Trying merge strategy $strategy..."
 295        ;;
 296    esac
 297
 298    # Remember which strategy left the state in the working tree
 299    wt_strategy=$strategy
 300
 301    git-merge-$strategy $common -- "$head_arg" "$@"
 302    exit=$?
 303    if test "$no_commit" = t && test "$exit" = 0
 304    then
 305        merge_was_ok=t
 306        exit=1 ;# pretend it left conflicts.
 307    fi
 308
 309    test "$exit" = 0 || {
 310
 311        # The backend exits with 1 when conflicts are left to be resolved,
 312        # with 2 when it does not handle the given merge at all.
 313
 314        if test "$exit" -eq 1
 315        then
 316            cnt=`{
 317                git-diff-files --name-only
 318                git-ls-files --unmerged
 319            } | wc -l`
 320            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 321            then
 322                best_strategy=$strategy
 323                best_cnt=$cnt
 324            fi
 325        fi
 326        continue
 327    }
 328
 329    # Automerge succeeded.
 330    result_tree=$(git-write-tree) && break
 331done
 332
 333# If we have a resulting tree, that means the strategy module
 334# auto resolved the merge cleanly.
 335if test '' != "$result_tree"
 336then
 337    parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
 338    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 339    finish "$result_commit" "Merge made by $wt_strategy."
 340    dropsave
 341    exit 0
 342fi
 343
 344# Pick the result from the best strategy and have the user fix it up.
 345case "$best_strategy" in
 346'')
 347        restorestate
 348        echo >&2 "No merge strategy handled the merge."
 349        exit 2
 350        ;;
 351"$wt_strategy")
 352        # We already have its result in the working tree.
 353        ;;
 354*)
 355        echo "Rewinding the tree to pristine..."
 356        restorestate
 357        echo "Using the $best_strategy to prepare resolving by hand."
 358        git-merge-$best_strategy $common -- "$head_arg" "$@"
 359        ;;
 360esac
 361
 362if test "$squash" = t
 363then
 364        finish
 365else
 366        for remote
 367        do
 368                echo $remote
 369        done >"$GIT_DIR/MERGE_HEAD"
 370        echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 371fi
 372
 373if test "$merge_was_ok" = t
 374then
 375        echo >&2 \
 376        "Automatic merge went well; stopped before committing as requested"
 377        exit 0
 378else
 379        {
 380            echo '
 381Conflicts:
 382'
 383                git ls-files --unmerged |
 384                sed -e 's/^[^   ]*      /       /' |
 385                uniq
 386        } >>"$GIT_DIR/MERGE_MSG"
 387        if test -d "$GIT_DIR/rr-cache"
 388        then
 389                git-rerere
 390        fi
 391        die "Automatic merge failed; fix conflicts and then commit the result."
 392fi