Andrew's git / gitweb.git /
3b041d81efd7e96a49c40eba0e23fc0b18508c82
   1#!/bin/sh
   2#
   3# Rewrite revision history
   4# Copyright (c) Petr Baudis, 2006
   5# Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
   6#
   7# Lets you rewrite the revision history of the current branch, creating
   8# a new branch. You can specify a number of filters to modify the commits,
   9# files and trees.
  10
  11warn () {
  12        echo "$*" >&2
  13}
  14
  15map()
  16{
  17        # if it was not rewritten, take the original
  18        if test -r "$workdir/../map/$1"
  19        then
  20                cat "$workdir/../map/$1"
  21        else
  22                echo "$1"
  23        fi
  24}
  25
  26# override die(): this version puts in an extra line break, so that
  27# the progress is still visible
  28
  29die()
  30{
  31        echo >&2
  32        echo "$*" >&2
  33        exit 1
  34}
  35
  36# When piped a commit, output a script to set the ident of either
  37# "author" or "committer
  38
  39set_ident () {
  40        lid="$(echo "$1" | tr "A-Z" "a-z")"
  41        uid="$(echo "$1" | tr "a-z" "A-Z")"
  42        pick_id_script='
  43                /^'$lid' /{
  44                        s/'\''/'\''\\'\'\''/g
  45                        h
  46                        s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
  47                        s/'\''/'\''\'\'\''/g
  48                        s/.*/export GIT_'$uid'_NAME='\''&'\''/p
  49
  50                        g
  51                        s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
  52                        s/'\''/'\''\'\'\''/g
  53                        s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
  54
  55                        g
  56                        s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
  57                        s/'\''/'\''\'\'\''/g
  58                        s/.*/export GIT_'$uid'_DATE='\''&'\''/p
  59
  60                        q
  61                }
  62        '
  63
  64        LANG=C LC_ALL=C sed -ne "$pick_id_script"
  65        # Ensure non-empty id name.
  66        echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
  67}
  68
  69# This script can be sourced by the commit filter to get the functions
  70test "a$SOURCE_FUNCTIONS" = a1 && return
  71this_script="$(cd "$(dirname "$0")"; pwd)"/$(basename "$0")
  72export this_script
  73
  74USAGE="[--env-filter <command>] [--tree-filter <command>] \
  75[--index-filter <command>] [--parent-filter <command>] \
  76[--msg-filter <command>] [--commit-filter <command>] \
  77[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
  78[--original <namespace>] [-d <directory>] [-f | --force] \
  79[<rev-list options>...]"
  80
  81. git-sh-setup
  82
  83tempdir=.git-rewrite
  84filter_env=
  85filter_tree=
  86filter_index=
  87filter_parent=
  88filter_msg=cat
  89filter_commit='git commit-tree "$@"'
  90filter_tag_name=
  91filter_subdir=
  92orig_namespace=refs/original/
  93force=
  94while case "$#" in 0) usage;; esac
  95do
  96        case "$1" in
  97        --)
  98                shift
  99                break
 100                ;;
 101        --force|-f)
 102                shift
 103                force=t
 104                continue
 105                ;;
 106        -*)
 107                ;;
 108        *)
 109                break;
 110        esac
 111
 112        # all switches take one argument
 113        ARG="$1"
 114        case "$#" in 1) usage ;; esac
 115        shift
 116        OPTARG="$1"
 117        shift
 118
 119        case "$ARG" in
 120        -d)
 121                tempdir="$OPTARG"
 122                ;;
 123        --env-filter)
 124                filter_env="$OPTARG"
 125                ;;
 126        --tree-filter)
 127                filter_tree="$OPTARG"
 128                ;;
 129        --index-filter)
 130                filter_index="$OPTARG"
 131                ;;
 132        --parent-filter)
 133                filter_parent="$OPTARG"
 134                ;;
 135        --msg-filter)
 136                filter_msg="$OPTARG"
 137                ;;
 138        --commit-filter)
 139                filter_commit='SOURCE_FUNCTIONS=1 . "$this_script";'" $OPTARG"
 140                ;;
 141        --tag-name-filter)
 142                filter_tag_name="$OPTARG"
 143                ;;
 144        --subdirectory-filter)
 145                filter_subdir="$OPTARG"
 146                ;;
 147        --original)
 148                orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
 149                ;;
 150        *)
 151                usage
 152                ;;
 153        esac
 154done
 155
 156case "$force" in
 157t)
 158        rm -rf "$tempdir"
 159;;
 160'')
 161        test -d "$tempdir" &&
 162                die "$tempdir already exists, please remove it"
 163esac
 164mkdir -p "$tempdir/t" &&
 165tempdir="$(cd "$tempdir"; pwd)" &&
 166cd "$tempdir/t" &&
 167workdir="$(pwd)" ||
 168die ""
 169
 170# Make sure refs/original is empty
 171git for-each-ref > "$tempdir"/backup-refs
 172while read sha1 type name
 173do
 174        case "$force,$name" in
 175        ,$orig_namespace*)
 176                die "Namespace $orig_namespace not empty"
 177        ;;
 178        t,$orig_namespace*)
 179                git update-ref -d "$name" $sha1
 180        ;;
 181        esac
 182done < "$tempdir"/backup-refs
 183
 184export GIT_DIR GIT_WORK_TREE=.
 185
 186# These refs should be updated if their heads were rewritten
 187
 188git rev-parse --revs-only --symbolic "$@" |
 189while read ref
 190do
 191        # normalize ref
 192        case "$ref" in
 193        HEAD)
 194                ref="$(git symbolic-ref "$ref")"
 195        ;;
 196        refs/*)
 197        ;;
 198        *)
 199                ref="$(git for-each-ref --format='%(refname)' |
 200                        grep /"$ref")"
 201        esac
 202
 203        git check-ref-format "$ref" && echo "$ref"
 204done > "$tempdir"/heads
 205
 206test -s "$tempdir"/heads ||
 207        die "Which ref do you want to rewrite?"
 208
 209export GIT_INDEX_FILE="$(pwd)/../index"
 210git read-tree || die "Could not seed the index"
 211
 212ret=0
 213
 214# map old->new commit ids for rewriting parents
 215mkdir ../map || die "Could not create map/ directory"
 216
 217case "$filter_subdir" in
 218"")
 219        git rev-list --reverse --topo-order --default HEAD \
 220                --parents "$@"
 221        ;;
 222*)
 223        git rev-list --reverse --topo-order --default HEAD \
 224                --parents --full-history "$@" -- "$filter_subdir"
 225esac > ../revs || die "Could not get the commits"
 226commits=$(wc -l <../revs | tr -d " ")
 227
 228test $commits -eq 0 && die "Found nothing to rewrite"
 229
 230# Rewrite the commits
 231
 232i=0
 233while read commit parents; do
 234        i=$(($i+1))
 235        printf "\rRewrite $commit ($i/$commits)"
 236
 237        case "$filter_subdir" in
 238        "")
 239                git read-tree -i -m $commit
 240                ;;
 241        *)
 242                git read-tree -i -m $commit:"$filter_subdir"
 243        esac || die "Could not initialize the index"
 244
 245        export GIT_COMMIT=$commit
 246        git cat-file commit "$commit" >../commit ||
 247                die "Cannot read commit $commit"
 248
 249        eval "$(set_ident AUTHOR <../commit)" ||
 250                die "setting author failed for commit $commit"
 251        eval "$(set_ident COMMITTER <../commit)" ||
 252                die "setting committer failed for commit $commit"
 253        eval "$filter_env" < /dev/null ||
 254                die "env filter failed: $filter_env"
 255
 256        if [ "$filter_tree" ]; then
 257                git checkout-index -f -u -a ||
 258                        die "Could not checkout the index"
 259                # files that $commit removed are now still in the working tree;
 260                # remove them, else they would be added again
 261                git ls-files -z --others | xargs -0 rm -f
 262                eval "$filter_tree" < /dev/null ||
 263                        die "tree filter failed: $filter_tree"
 264
 265                git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
 266                        xargs -0 git update-index --add --replace --remove
 267                git ls-files -z --others | \
 268                        xargs -0 git update-index --add --replace --remove
 269        fi
 270
 271        eval "$filter_index" < /dev/null ||
 272                die "index filter failed: $filter_index"
 273
 274        parentstr=
 275        for parent in $parents; do
 276                for reparent in $(map "$parent"); do
 277                        parentstr="$parentstr -p $reparent"
 278                done
 279        done
 280        if [ "$filter_parent" ]; then
 281                parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
 282                                die "parent filter failed: $filter_parent"
 283        fi
 284
 285        sed -e '1,/^$/d' <../commit | \
 286                eval "$filter_msg" > ../message ||
 287                        die "msg filter failed: $filter_msg"
 288        sh -c "$filter_commit" "git commit-tree" \
 289                $(git write-tree) $parentstr < ../message > ../map/$commit
 290done <../revs
 291
 292# In case of a subdirectory filter, it is possible that a specified head
 293# is not in the set of rewritten commits, because it was pruned by the
 294# revision walker.  Fix it by mapping these heads to the next rewritten
 295# ancestor(s), i.e. the boundaries in the set of rewritten commits.
 296
 297# NEEDSWORK: we should sort the unmapped refs topologically first
 298while read ref
 299do
 300        sha1=$(git rev-parse "$ref"^0)
 301        test -f "$workdir"/../map/$sha1 && continue
 302        # Assign the boundarie(s) in the set of rewritten commits
 303        # as the replacement commit(s).
 304        # (This would look a bit nicer if --not --stdin worked.)
 305        for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
 306                git rev-list $ref --boundary --stdin |
 307                sed -n "s/^-//p")
 308        do
 309                map $p >> "$workdir"/../map/$sha1
 310        done
 311done < "$tempdir"/heads
 312
 313# Finally update the refs
 314
 315_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
 316_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 317count=0
 318echo
 319while read ref
 320do
 321        # avoid rewriting a ref twice
 322        test -f "$orig_namespace$ref" && continue
 323
 324        sha1=$(git rev-parse "$ref"^0)
 325        rewritten=$(map $sha1)
 326
 327        test $sha1 = "$rewritten" &&
 328                warn "WARNING: Ref '$ref' is unchanged" &&
 329                continue
 330
 331        case "$rewritten" in
 332        '')
 333                echo "Ref '$ref' was deleted"
 334                git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
 335                        die "Could not delete $ref"
 336        ;;
 337        $_x40)
 338                echo "Ref '$ref' was rewritten"
 339                git update-ref -m "filter-branch: rewrite" \
 340                                "$ref" $rewritten $sha1 ||
 341                        die "Could not rewrite $ref"
 342        ;;
 343        *)
 344                # NEEDSWORK: possibly add -Werror, making this an error
 345                warn "WARNING: '$ref' was rewritten into multiple commits:"
 346                warn "$rewritten"
 347                warn "WARNING: Ref '$ref' points to the first one now."
 348                rewritten=$(echo "$rewritten" | head -n 1)
 349                git update-ref -m "filter-branch: rewrite to first" \
 350                                "$ref" $rewritten $sha1 ||
 351                        die "Could not rewrite $ref"
 352        ;;
 353        esac
 354        git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
 355        count=$(($count+1))
 356done < "$tempdir"/heads
 357
 358# TODO: This should possibly go, with the semantics that all positive given
 359#       refs are updated, and their original heads stored in refs/original/
 360# Filter tags
 361
 362if [ "$filter_tag_name" ]; then
 363        git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
 364        while read sha1 type ref; do
 365                ref="${ref#refs/tags/}"
 366                # XXX: Rewrite tagged trees as well?
 367                if [ "$type" != "commit" -a "$type" != "tag" ]; then
 368                        continue;
 369                fi
 370
 371                if [ "$type" = "tag" ]; then
 372                        # Dereference to a commit
 373                        sha1t="$sha1"
 374                        sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
 375                fi
 376
 377                [ -f "../map/$sha1" ] || continue
 378                new_sha1="$(cat "../map/$sha1")"
 379                export GIT_COMMIT="$sha1"
 380                new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
 381                        die "tag name filter failed: $filter_tag_name"
 382
 383                echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 384
 385                if [ "$type" = "tag" ]; then
 386                        # Warn that we are not rewriting the tag object itself.
 387                        warn "unreferencing tag object $sha1t"
 388                fi
 389
 390                git update-ref "refs/tags/$new_ref" "$new_sha1" ||
 391                        die "Could not write tag $new_ref"
 392        done
 393fi
 394
 395cd ../..
 396rm -rf "$tempdir"
 397echo
 398test $count -gt 0 && echo "These refs were rewritten:"
 399git show-ref | grep ^"$orig_namespace"
 400
 401exit $ret