Andrew's git - gitweb.git/blob - git-filter-branch.sh

   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
  11USAGE="git-filter-branch [-d TEMPDIR] [FILTERS] DESTBRANCH [REV-RANGE]"
  12. git-sh-setup
  13
  14warn () {
  15        echo "$*" >&2
  16}
  17
  18map()
  19{
  20        # if it was not rewritten, take the original
  21        if test -r "$workdir/../map/$1"
  22        then
  23                cat "$workdir/../map/$1"
  24        else
  25                echo "$1"
  26        fi
  27}
  28
  29# override die(): this version puts in an extra line break, so that
  30# the progress is still visible
  31
  32die()
  33{
  34        echo >&2
  35        echo "$*" >&2
  36        exit 1
  37}
  38
  39# When piped a commit, output a script to set the ident of either
  40# "author" or "committer
  41
  42set_ident () {
  43        lid="$(echo "$1" | tr "A-Z" "a-z")"
  44        uid="$(echo "$1" | tr "a-z" "A-Z")"
  45        pick_id_script='
  46                /^'$lid' /{
  47                        s/'\''/'\''\\'\'\''/g
  48                        h
  49                        s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
  50                        s/'\''/'\''\'\'\''/g
  51                        s/.*/export GIT_'$uid'_NAME='\''&'\''/p
  52
  53                        g
  54                        s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
  55                        s/'\''/'\''\'\'\''/g
  56                        s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
  57
  58                        g
  59                        s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
  60                        s/'\''/'\''\'\'\''/g
  61                        s/.*/export GIT_'$uid'_DATE='\''&'\''/p
  62
  63                        q
  64                }
  65        '
  66
  67        LANG=C LC_ALL=C sed -ne "$pick_id_script"
  68        # Ensure non-empty id name.
  69        echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
  70}
  71
  72tempdir=.git-rewrite
  73filter_env=
  74filter_tree=
  75filter_index=
  76filter_parent=
  77filter_msg=cat
  78filter_commit='git commit-tree "$@"'
  79filter_tag_name=
  80filter_subdir=
  81while case "$#" in 0) usage;; esac
  82do
  83        case "$1" in
  84        --)
  85                shift
  86                break
  87                ;;
  88        -*)
  89                ;;
  90        *)
  91                break;
  92        esac
  93
  94        # all switches take one argument
  95        ARG="$1"
  96        case "$#" in 1) usage ;; esac
  97        shift
  98        OPTARG="$1"
  99        shift
 100
 101        case "$ARG" in
 102        -d)
 103                tempdir="$OPTARG"
 104                ;;
 105        --env-filter)
 106                filter_env="$OPTARG"
 107                ;;
 108        --tree-filter)
 109                filter_tree="$OPTARG"
 110                ;;
 111        --index-filter)
 112                filter_index="$OPTARG"
 113                ;;
 114        --parent-filter)
 115                filter_parent="$OPTARG"
 116                ;;
 117        --msg-filter)
 118                filter_msg="$OPTARG"
 119                ;;
 120        --commit-filter)
 121                filter_commit="$OPTARG"
 122                ;;
 123        --tag-name-filter)
 124                filter_tag_name="$OPTARG"
 125                ;;
 126        --subdirectory-filter)
 127                filter_subdir="$OPTARG"
 128                ;;
 129        *)
 130                usage
 131                ;;
 132        esac
 133done
 134
 135dstbranch="$1"
 136shift
 137test -n "$dstbranch" || die "missing branch name"
 138git show-ref "refs/heads/$dstbranch" 2> /dev/null &&
 139        die "branch $dstbranch already exists"
 140
 141test ! -e "$tempdir" || die "$tempdir already exists, please remove it"
 142mkdir -p "$tempdir/t" &&
 143cd "$tempdir/t" &&
 144workdir="$(pwd)" ||
 145die ""
 146
 147case "$GIT_DIR" in
 148/*)
 149        ;;
 150*)
 151        GIT_DIR="$(pwd)/../../$GIT_DIR"
 152        ;;
 153esac
 154export GIT_DIR GIT_WORK_TREE=.
 155
 156export GIT_INDEX_FILE="$(pwd)/../index"
 157git read-tree || die "Could not seed the index"
 158
 159ret=0
 160
 161# map old->new commit ids for rewriting parents
 162mkdir ../map || die "Could not create map/ directory"
 163
 164case "$filter_subdir" in
 165"")
 166        git rev-list --reverse --topo-order --default HEAD \
 167                --parents "$@"
 168        ;;
 169*)
 170        git rev-list --reverse --topo-order --default HEAD \
 171                --parents --full-history "$@" -- "$filter_subdir"
 172esac > ../revs || die "Could not get the commits"
 173commits=$(wc -l <../revs | tr -d " ")
 174
 175test $commits -eq 0 && die "Found nothing to rewrite"
 176
 177i=0
 178while read commit parents; do
 179        i=$(($i+1))
 180        printf "\rRewrite $commit ($i/$commits)"
 181
 182        case "$filter_subdir" in
 183        "")
 184                git read-tree -i -m $commit
 185                ;;
 186        *)
 187                git read-tree -i -m $commit:"$filter_subdir"
 188        esac || die "Could not initialize the index"
 189
 190        export GIT_COMMIT=$commit
 191        git cat-file commit "$commit" >../commit ||
 192                die "Cannot read commit $commit"
 193
 194        eval "$(set_ident AUTHOR <../commit)" ||
 195                die "setting author failed for commit $commit"
 196        eval "$(set_ident COMMITTER <../commit)" ||
 197                die "setting committer failed for commit $commit"
 198        eval "$filter_env" < /dev/null ||
 199                die "env filter failed: $filter_env"
 200
 201        if [ "$filter_tree" ]; then
 202                git checkout-index -f -u -a ||
 203                        die "Could not checkout the index"
 204                # files that $commit removed are now still in the working tree;
 205                # remove them, else they would be added again
 206                git ls-files -z --others | xargs -0 rm -f
 207                eval "$filter_tree" < /dev/null ||
 208                        die "tree filter failed: $filter_tree"
 209
 210                git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
 211                        xargs -0 git update-index --add --replace --remove
 212                git ls-files -z --others | \
 213                        xargs -0 git update-index --add --replace --remove
 214        fi
 215
 216        eval "$filter_index" < /dev/null ||
 217                die "index filter failed: $filter_index"
 218
 219        parentstr=
 220        for parent in $parents; do
 221                for reparent in $(map "$parent"); do
 222                        parentstr="$parentstr -p $reparent"
 223                done
 224        done
 225        if [ "$filter_parent" ]; then
 226                parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
 227                                die "parent filter failed: $filter_parent"
 228        fi
 229
 230        sed -e '1,/^$/d' <../commit | \
 231                eval "$filter_msg" > ../message ||
 232                        die "msg filter failed: $filter_msg"
 233        sh -c "$filter_commit" "git commit-tree" \
 234                $(git write-tree) $parentstr < ../message > ../map/$commit
 235done <../revs
 236
 237src_head=$(tail -n 1 ../revs | sed -e 's/ .*//')
 238target_head=$(head -n 1 ../map/$src_head)
 239case "$target_head" in
 240'')
 241        echo Nothing rewritten
 242        ;;
 243*)
 244        git update-ref refs/heads/"$dstbranch" $target_head ||
 245                die "Could not update $dstbranch with $target_head"
 246        if [ $(wc -l <../map/$src_head) -gt 1 ]; then
 247                echo "WARNING: Your commit filter caused the head commit to expand to several rewritten commits. Only the first such commit was recorded as the current $dstbranch head but you will need to resolve the situation now (probably by manually merging the other commits). These are all the commits:" >&2
 248                sed 's/^/       /' ../map/$src_head >&2
 249                ret=1
 250        fi
 251        ;;
 252esac
 253
 254if [ "$filter_tag_name" ]; then
 255        git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
 256        while read sha1 type ref; do
 257                ref="${ref#refs/tags/}"
 258                # XXX: Rewrite tagged trees as well?
 259                if [ "$type" != "commit" -a "$type" != "tag" ]; then
 260                        continue;
 261                fi
 262
 263                if [ "$type" = "tag" ]; then
 264                        # Dereference to a commit
 265                        sha1t="$sha1"
 266                        sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
 267                fi
 268
 269                [ -f "../map/$sha1" ] || continue
 270                new_sha1="$(cat "../map/$sha1")"
 271                export GIT_COMMIT="$sha1"
 272                new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
 273                        die "tag name filter failed: $filter_tag_name"
 274
 275                echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 276
 277                if [ "$type" = "tag" ]; then
 278                        # Warn that we are not rewriting the tag object itself.
 279                        warn "unreferencing tag object $sha1t"
 280                fi
 281
 282                git update-ref "refs/tags/$new_ref" "$new_sha1" ||
 283                        die "Could not write tag $new_ref"
 284        done
 285fi
 286
 287cd ../..
 288rm -rf "$tempdir"
 289printf "\nRewritten history saved to the $dstbranch branch\n"
 290
 291exit $ret