Andrew's git / gitweb.git / git-filter-branch.sh
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git-filter-branch.shon commit Merge branch 'jc/autogc' into js/rebase-i (61ab92d)
   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 "$1"
  23        fi
  24}
  25
  26# if you run 'skip_commit "$@"' in a commit filter, it will print
  27# the (mapped) parents, effectively skipping the commit.
  28
  29skip_commit()
  30{
  31        shift;
  32        while [ -n "$1" ];
  33        do
  34                shift;
  35                map "$1";
  36                shift;
  37        done;
  38}
  39
  40# override die(): this version puts in an extra line break, so that
  41# the progress is still visible
  42
  43die()
  44{
  45        echo >&2
  46        echo "$*" >&2
  47        exit 1
  48}
  49
  50# When piped a commit, output a script to set the ident of either
  51# "author" or "committer
  52
  53set_ident () {
  54        lid="$(echo "$1" | tr "A-Z" "a-z")"
  55        uid="$(echo "$1" | tr "a-z" "A-Z")"
  56        pick_id_script='
  57                /^'$lid' /{
  58                        s/'\''/'\''\\'\'\''/g
  59                        h
  60                        s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
  61                        s/'\''/'\''\'\'\''/g
  62                        s/.*/export GIT_'$uid'_NAME='\''&'\''/p
  63
  64                        g
  65                        s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
  66                        s/'\''/'\''\'\'\''/g
  67                        s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
  68
  69                        g
  70                        s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
  71                        s/'\''/'\''\'\'\''/g
  72                        s/.*/export GIT_'$uid'_DATE='\''&'\''/p
  73
  74                        q
  75                }
  76        '
  77
  78        LANG=C LC_ALL=C sed -ne "$pick_id_script"
  79        # Ensure non-empty id name.
  80        echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
  81}
  82
  83# This script can be sourced by the commit filter to get the functions
  84test "a$SOURCE_FUNCTIONS" = a1 && return
  85this_script="$(cd "$(dirname "$0")"; pwd)"/$(basename "$0")
  86export this_script
  87
  88USAGE="[--env-filter <command>] [--tree-filter <command>] \
  89[--index-filter <command>] [--parent-filter <command>] \
  90[--msg-filter <command>] [--commit-filter <command>] \
  91[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
  92[--original <namespace>] [-d <directory>] [-f | --force] \
  93[<rev-list options>...]"
  94
  95. git-sh-setup
  96
  97tempdir=.git-rewrite
  98filter_env=
  99filter_tree=
 100filter_index=
 101filter_parent=
 102filter_msg=cat
 103filter_commit='git commit-tree "$@"'
 104filter_tag_name=
 105filter_subdir=
 106orig_namespace=refs/original/
 107force=
 108while :
 109do
 110        test $# = 0 && usage
 111        case "$1" in
 112        --)
 113                shift
 114                break
 115                ;;
 116        --force|-f)
 117                shift
 118                force=t
 119                continue
 120                ;;
 121        -*)
 122                ;;
 123        *)
 124                break;
 125        esac
 126
 127        # all switches take one argument
 128        ARG="$1"
 129        case "$#" in 1) usage ;; esac
 130        shift
 131        OPTARG="$1"
 132        shift
 133
 134        case "$ARG" in
 135        -d)
 136                tempdir="$OPTARG"
 137                ;;
 138        --env-filter)
 139                filter_env="$OPTARG"
 140                ;;
 141        --tree-filter)
 142                filter_tree="$OPTARG"
 143                ;;
 144        --index-filter)
 145                filter_index="$OPTARG"
 146                ;;
 147        --parent-filter)
 148                filter_parent="$OPTARG"
 149                ;;
 150        --msg-filter)
 151                filter_msg="$OPTARG"
 152                ;;
 153        --commit-filter)
 154                filter_commit='SOURCE_FUNCTIONS=1 . "$this_script";'" $OPTARG"
 155                ;;
 156        --tag-name-filter)
 157                filter_tag_name="$OPTARG"
 158                ;;
 159        --subdirectory-filter)
 160                filter_subdir="$OPTARG"
 161                ;;
 162        --original)
 163                orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
 164                ;;
 165        *)
 166                usage
 167                ;;
 168        esac
 169done
 170
 171case "$force" in
 172t)
 173        rm -rf "$tempdir"
 174;;
 175'')
 176        test -d "$tempdir" &&
 177                die "$tempdir already exists, please remove it"
 178esac
 179mkdir -p "$tempdir/t" &&
 180tempdir="$(cd "$tempdir"; pwd)" &&
 181cd "$tempdir/t" &&
 182workdir="$(pwd)" ||
 183die ""
 184
 185# Make sure refs/original is empty
 186git for-each-ref > "$tempdir"/backup-refs
 187while read sha1 type name
 188do
 189        case "$force,$name" in
 190        ,$orig_namespace*)
 191                die "Namespace $orig_namespace not empty"
 192        ;;
 193        t,$orig_namespace*)
 194                git update-ref -d "$name" $sha1
 195        ;;
 196        esac
 197done < "$tempdir"/backup-refs
 198
 199export GIT_DIR GIT_WORK_TREE=.
 200
 201# These refs should be updated if their heads were rewritten
 202
 203git rev-parse --revs-only --symbolic "$@" |
 204while read ref
 205do
 206        # normalize ref
 207        case "$ref" in
 208        HEAD)
 209                ref="$(git symbolic-ref "$ref")"
 210        ;;
 211        refs/*)
 212        ;;
 213        *)
 214                ref="$(git for-each-ref --format='%(refname)' |
 215                        grep /"$ref")"
 216        esac
 217
 218        git check-ref-format "$ref" && echo "$ref"
 219done > "$tempdir"/heads
 220
 221test -s "$tempdir"/heads ||
 222        die "Which ref do you want to rewrite?"
 223
 224export GIT_INDEX_FILE="$(pwd)/../index"
 225git read-tree || die "Could not seed the index"
 226
 227ret=0
 228
 229# map old->new commit ids for rewriting parents
 230mkdir ../map || die "Could not create map/ directory"
 231
 232case "$filter_subdir" in
 233"")
 234        git rev-list --reverse --topo-order --default HEAD \
 235                --parents "$@"
 236        ;;
 237*)
 238        git rev-list --reverse --topo-order --default HEAD \
 239                --parents --full-history "$@" -- "$filter_subdir"
 240esac > ../revs || die "Could not get the commits"
 241commits=$(wc -l <../revs | tr -d " ")
 242
 243test $commits -eq 0 && die "Found nothing to rewrite"
 244
 245# Rewrite the commits
 246
 247i=0
 248while read commit parents; do
 249        i=$(($i+1))
 250        printf "\rRewrite $commit ($i/$commits)"
 251
 252        case "$filter_subdir" in
 253        "")
 254                git read-tree -i -m $commit
 255                ;;
 256        *)
 257                git read-tree -i -m $commit:"$filter_subdir"
 258        esac || die "Could not initialize the index"
 259
 260        export GIT_COMMIT=$commit
 261        git cat-file commit "$commit" >../commit ||
 262                die "Cannot read commit $commit"
 263
 264        eval "$(set_ident AUTHOR <../commit)" ||
 265                die "setting author failed for commit $commit"
 266        eval "$(set_ident COMMITTER <../commit)" ||
 267                die "setting committer failed for commit $commit"
 268        eval "$filter_env" < /dev/null ||
 269                die "env filter failed: $filter_env"
 270
 271        if [ "$filter_tree" ]; then
 272                git checkout-index -f -u -a ||
 273                        die "Could not checkout the index"
 274                # files that $commit removed are now still in the working tree;
 275                # remove them, else they would be added again
 276                git ls-files -z --others | xargs -0 rm -f
 277                eval "$filter_tree" < /dev/null ||
 278                        die "tree filter failed: $filter_tree"
 279
 280                git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
 281                        xargs -0 git update-index --add --replace --remove
 282                git ls-files -z --others | \
 283                        xargs -0 git update-index --add --replace --remove
 284        fi
 285
 286        eval "$filter_index" < /dev/null ||
 287                die "index filter failed: $filter_index"
 288
 289        parentstr=
 290        for parent in $parents; do
 291                for reparent in $(map "$parent"); do
 292                        parentstr="$parentstr -p $reparent"
 293                done
 294        done
 295        if [ "$filter_parent" ]; then
 296                parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
 297                                die "parent filter failed: $filter_parent"
 298        fi
 299
 300        sed -e '1,/^$/d' <../commit | \
 301                eval "$filter_msg" > ../message ||
 302                        die "msg filter failed: $filter_msg"
 303        sh -c "$filter_commit" "git commit-tree" \
 304                $(git write-tree) $parentstr < ../message > ../map/$commit
 305done <../revs
 306
 307# In case of a subdirectory filter, it is possible that a specified head
 308# is not in the set of rewritten commits, because it was pruned by the
 309# revision walker.  Fix it by mapping these heads to the next rewritten
 310# ancestor(s), i.e. the boundaries in the set of rewritten commits.
 311
 312# NEEDSWORK: we should sort the unmapped refs topologically first
 313while read ref
 314do
 315        sha1=$(git rev-parse "$ref"^0)
 316        test -f "$workdir"/../map/$sha1 && continue
 317        # Assign the boundarie(s) in the set of rewritten commits
 318        # as the replacement commit(s).
 319        # (This would look a bit nicer if --not --stdin worked.)
 320        for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
 321                git rev-list $ref --boundary --stdin |
 322                sed -n "s/^-//p")
 323        do
 324                map $p >> "$workdir"/../map/$sha1
 325        done
 326done < "$tempdir"/heads
 327
 328# Finally update the refs
 329
 330_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
 331_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 332count=0
 333echo
 334while read ref
 335do
 336        # avoid rewriting a ref twice
 337        test -f "$orig_namespace$ref" && continue
 338
 339        sha1=$(git rev-parse "$ref"^0)
 340        rewritten=$(map $sha1)
 341
 342        test $sha1 = "$rewritten" &&
 343                warn "WARNING: Ref '$ref' is unchanged" &&
 344                continue
 345
 346        case "$rewritten" in
 347        '')
 348                echo "Ref '$ref' was deleted"
 349                git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
 350                        die "Could not delete $ref"
 351        ;;
 352        $_x40)
 353                echo "Ref '$ref' was rewritten"
 354                git update-ref -m "filter-branch: rewrite" \
 355                                "$ref" $rewritten $sha1 ||
 356                        die "Could not rewrite $ref"
 357        ;;
 358        *)
 359                # NEEDSWORK: possibly add -Werror, making this an error
 360                warn "WARNING: '$ref' was rewritten into multiple commits:"
 361                warn "$rewritten"
 362                warn "WARNING: Ref '$ref' points to the first one now."
 363                rewritten=$(echo "$rewritten" | head -n 1)
 364                git update-ref -m "filter-branch: rewrite to first" \
 365                                "$ref" $rewritten $sha1 ||
 366                        die "Could not rewrite $ref"
 367        ;;
 368        esac
 369        git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
 370        count=$(($count+1))
 371done < "$tempdir"/heads
 372
 373# TODO: This should possibly go, with the semantics that all positive given
 374#       refs are updated, and their original heads stored in refs/original/
 375# Filter tags
 376
 377if [ "$filter_tag_name" ]; then
 378        git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
 379        while read sha1 type ref; do
 380                ref="${ref#refs/tags/}"
 381                # XXX: Rewrite tagged trees as well?
 382                if [ "$type" != "commit" -a "$type" != "tag" ]; then
 383                        continue;
 384                fi
 385
 386                if [ "$type" = "tag" ]; then
 387                        # Dereference to a commit
 388                        sha1t="$sha1"
 389                        sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
 390                fi
 391
 392                [ -f "../map/$sha1" ] || continue
 393                new_sha1="$(cat "../map/$sha1")"
 394                export GIT_COMMIT="$sha1"
 395                new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
 396                        die "tag name filter failed: $filter_tag_name"
 397
 398                echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 399
 400                if [ "$type" = "tag" ]; then
 401                        # Warn that we are not rewriting the tag object itself.
 402                        warn "unreferencing tag object $sha1t"
 403                fi
 404
 405                git update-ref "refs/tags/$new_ref" "$new_sha1" ||
 406                        die "Could not write tag $new_ref"
 407        done
 408fi
 409
 410cd ../..
 411rm -rf "$tempdir"
 412echo
 413test $count -gt 0 && echo "These refs were rewritten:"
 414git show-ref | grep ^"$orig_namespace"
 415
 416exit $ret