Andrew's git / gitweb.git /
29d35fd27c52abf208f57e2a99d3de6e6ff2f977
   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
  11# The following functions will also be available in the commit filter:
  12
  13functions=$(cat << \EOF
  14warn () {
  15        echo "$*" >&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 "$1"
  26        fi
  27}
  28
  29# if you run 'skip_commit "$@"' in a commit filter, it will print
  30# the (mapped) parents, effectively skipping the commit.
  31
  32skip_commit()
  33{
  34        shift;
  35        while [ -n "$1" ];
  36        do
  37                shift;
  38                map "$1";
  39                shift;
  40        done;
  41}
  42
  43# override die(): this version puts in an extra line break, so that
  44# the progress is still visible
  45
  46die()
  47{
  48        echo >&2
  49        echo "$*" >&2
  50        exit 1
  51}
  52EOF
  53)
  54
  55eval "$functions"
  56
  57# When piped a commit, output a script to set the ident of either
  58# "author" or "committer
  59
  60set_ident () {
  61        lid="$(echo "$1" | tr "A-Z" "a-z")"
  62        uid="$(echo "$1" | tr "a-z" "A-Z")"
  63        pick_id_script='
  64                /^'$lid' /{
  65                        s/'\''/'\''\\'\'\''/g
  66                        h
  67                        s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
  68                        s/'\''/'\''\'\'\''/g
  69                        s/.*/GIT_'$uid'_NAME='\''&'\''; export GIT_'$uid'_NAME/p
  70
  71                        g
  72                        s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
  73                        s/'\''/'\''\'\'\''/g
  74                        s/.*/GIT_'$uid'_EMAIL='\''&'\''; export GIT_'$uid'_EMAIL/p
  75
  76                        g
  77                        s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
  78                        s/'\''/'\''\'\'\''/g
  79                        s/.*/GIT_'$uid'_DATE='\''&'\''; export GIT_'$uid'_DATE/p
  80
  81                        q
  82                }
  83        '
  84
  85        LANG=C LC_ALL=C sed -ne "$pick_id_script"
  86        # Ensure non-empty id name.
  87        echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
  88}
  89
  90USAGE="[--env-filter <command>] [--tree-filter <command>] \
  91[--index-filter <command>] [--parent-filter <command>] \
  92[--msg-filter <command>] [--commit-filter <command>] \
  93[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
  94[--original <namespace>] [-d <directory>] [-f | --force] \
  95[<rev-list options>...]"
  96
  97OPTIONS_SPEC=
  98. git-sh-setup
  99
 100git diff-files --quiet &&
 101        git diff-index --cached --quiet HEAD -- ||
 102        die "Cannot rewrite branch(es) with a dirty working directory."
 103
 104tempdir=.git-rewrite
 105filter_env=
 106filter_tree=
 107filter_index=
 108filter_parent=
 109filter_msg=cat
 110filter_commit='git commit-tree "$@"'
 111filter_tag_name=
 112filter_subdir=
 113orig_namespace=refs/original/
 114force=
 115while :
 116do
 117        test $# = 0 && usage
 118        case "$1" in
 119        --)
 120                shift
 121                break
 122                ;;
 123        --force|-f)
 124                shift
 125                force=t
 126                continue
 127                ;;
 128        -*)
 129                ;;
 130        *)
 131                break;
 132        esac
 133
 134        # all switches take one argument
 135        ARG="$1"
 136        case "$#" in 1) usage ;; esac
 137        shift
 138        OPTARG="$1"
 139        shift
 140
 141        case "$ARG" in
 142        -d)
 143                tempdir="$OPTARG"
 144                ;;
 145        --env-filter)
 146                filter_env="$OPTARG"
 147                ;;
 148        --tree-filter)
 149                filter_tree="$OPTARG"
 150                ;;
 151        --index-filter)
 152                filter_index="$OPTARG"
 153                ;;
 154        --parent-filter)
 155                filter_parent="$OPTARG"
 156                ;;
 157        --msg-filter)
 158                filter_msg="$OPTARG"
 159                ;;
 160        --commit-filter)
 161                filter_commit="$functions; $OPTARG"
 162                ;;
 163        --tag-name-filter)
 164                filter_tag_name="$OPTARG"
 165                ;;
 166        --subdirectory-filter)
 167                filter_subdir="$OPTARG"
 168                ;;
 169        --original)
 170                orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
 171                ;;
 172        *)
 173                usage
 174                ;;
 175        esac
 176done
 177
 178case "$force" in
 179t)
 180        rm -rf "$tempdir"
 181;;
 182'')
 183        test -d "$tempdir" &&
 184                die "$tempdir already exists, please remove it"
 185esac
 186mkdir -p "$tempdir/t" &&
 187tempdir="$(cd "$tempdir"; pwd)" &&
 188cd "$tempdir/t" &&
 189workdir="$(pwd)" ||
 190die ""
 191
 192# Make sure refs/original is empty
 193git for-each-ref > "$tempdir"/backup-refs
 194while read sha1 type name
 195do
 196        case "$force,$name" in
 197        ,$orig_namespace*)
 198                die "Namespace $orig_namespace not empty"
 199        ;;
 200        t,$orig_namespace*)
 201                git update-ref -d "$name" $sha1
 202        ;;
 203        esac
 204done < "$tempdir"/backup-refs
 205
 206ORIG_GIT_DIR="$GIT_DIR"
 207ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
 208ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
 209GIT_WORK_TREE=.
 210export GIT_DIR GIT_WORK_TREE
 211
 212# These refs should be updated if their heads were rewritten
 213
 214git rev-parse --revs-only --symbolic "$@" |
 215while read ref
 216do
 217        # normalize ref
 218        case "$ref" in
 219        HEAD)
 220                ref="$(git symbolic-ref "$ref")"
 221        ;;
 222        refs/*)
 223        ;;
 224        *)
 225                ref="$(git for-each-ref --format='%(refname)' |
 226                        grep /"$ref")"
 227        esac
 228
 229        git check-ref-format "$ref" && echo "$ref"
 230done > "$tempdir"/heads
 231
 232test -s "$tempdir"/heads ||
 233        die "Which ref do you want to rewrite?"
 234
 235GIT_INDEX_FILE="$(pwd)/../index"
 236export GIT_INDEX_FILE
 237git read-tree || die "Could not seed the index"
 238
 239ret=0
 240
 241# map old->new commit ids for rewriting parents
 242mkdir ../map || die "Could not create map/ directory"
 243
 244case "$filter_subdir" in
 245"")
 246        git rev-list --reverse --topo-order --default HEAD \
 247                --parents "$@"
 248        ;;
 249*)
 250        git rev-list --reverse --topo-order --default HEAD \
 251                --parents --full-history "$@" -- "$filter_subdir"
 252esac > ../revs || die "Could not get the commits"
 253commits=$(wc -l <../revs | tr -d " ")
 254
 255test $commits -eq 0 && die "Found nothing to rewrite"
 256
 257# Rewrite the commits
 258
 259i=0
 260while read commit parents; do
 261        i=$(($i+1))
 262        printf "\rRewrite $commit ($i/$commits)"
 263
 264        case "$filter_subdir" in
 265        "")
 266                git read-tree -i -m $commit
 267                ;;
 268        *)
 269                git read-tree -i -m $commit:"$filter_subdir"
 270        esac || die "Could not initialize the index"
 271
 272        GIT_COMMIT=$commit
 273        export GIT_COMMIT
 274        git cat-file commit "$commit" >../commit ||
 275                die "Cannot read commit $commit"
 276
 277        eval "$(set_ident AUTHOR <../commit)" ||
 278                die "setting author failed for commit $commit"
 279        eval "$(set_ident COMMITTER <../commit)" ||
 280                die "setting committer failed for commit $commit"
 281        eval "$filter_env" < /dev/null ||
 282                die "env filter failed: $filter_env"
 283
 284        if [ "$filter_tree" ]; then
 285                git checkout-index -f -u -a ||
 286                        die "Could not checkout the index"
 287                # files that $commit removed are now still in the working tree;
 288                # remove them, else they would be added again
 289                git ls-files -z --others | xargs -0 rm -f
 290                eval "$filter_tree" < /dev/null ||
 291                        die "tree filter failed: $filter_tree"
 292
 293                git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
 294                        xargs -0 git update-index --add --replace --remove
 295                git ls-files -z --others | \
 296                        xargs -0 git update-index --add --replace --remove
 297        fi
 298
 299        eval "$filter_index" < /dev/null ||
 300                die "index filter failed: $filter_index"
 301
 302        parentstr=
 303        for parent in $parents; do
 304                for reparent in $(map "$parent"); do
 305                        parentstr="$parentstr -p $reparent"
 306                done
 307        done
 308        if [ "$filter_parent" ]; then
 309                parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
 310                                die "parent filter failed: $filter_parent"
 311        fi
 312
 313        sed -e '1,/^$/d' <../commit | \
 314                eval "$filter_msg" > ../message ||
 315                        die "msg filter failed: $filter_msg"
 316        sh -c "$filter_commit" "git commit-tree" \
 317                $(git write-tree) $parentstr < ../message > ../map/$commit
 318done <../revs
 319
 320# In case of a subdirectory filter, it is possible that a specified head
 321# is not in the set of rewritten commits, because it was pruned by the
 322# revision walker.  Fix it by mapping these heads to the next rewritten
 323# ancestor(s), i.e. the boundaries in the set of rewritten commits.
 324
 325# NEEDSWORK: we should sort the unmapped refs topologically first
 326while read ref
 327do
 328        sha1=$(git rev-parse "$ref"^0)
 329        test -f "$workdir"/../map/$sha1 && continue
 330        # Assign the boundarie(s) in the set of rewritten commits
 331        # as the replacement commit(s).
 332        # (This would look a bit nicer if --not --stdin worked.)
 333        for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
 334                git rev-list $ref --boundary --stdin |
 335                sed -n "s/^-//p")
 336        do
 337                map $p >> "$workdir"/../map/$sha1
 338        done
 339done < "$tempdir"/heads
 340
 341# Finally update the refs
 342
 343_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
 344_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 345count=0
 346echo
 347while read ref
 348do
 349        # avoid rewriting a ref twice
 350        test -f "$orig_namespace$ref" && continue
 351
 352        sha1=$(git rev-parse "$ref"^0)
 353        rewritten=$(map $sha1)
 354
 355        test $sha1 = "$rewritten" &&
 356                warn "WARNING: Ref '$ref' is unchanged" &&
 357                continue
 358
 359        case "$rewritten" in
 360        '')
 361                echo "Ref '$ref' was deleted"
 362                git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
 363                        die "Could not delete $ref"
 364        ;;
 365        $_x40)
 366                echo "Ref '$ref' was rewritten"
 367                git update-ref -m "filter-branch: rewrite" \
 368                                "$ref" $rewritten $sha1 ||
 369                        die "Could not rewrite $ref"
 370        ;;
 371        *)
 372                # NEEDSWORK: possibly add -Werror, making this an error
 373                warn "WARNING: '$ref' was rewritten into multiple commits:"
 374                warn "$rewritten"
 375                warn "WARNING: Ref '$ref' points to the first one now."
 376                rewritten=$(echo "$rewritten" | head -n 1)
 377                git update-ref -m "filter-branch: rewrite to first" \
 378                                "$ref" $rewritten $sha1 ||
 379                        die "Could not rewrite $ref"
 380        ;;
 381        esac
 382        git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
 383        count=$(($count+1))
 384done < "$tempdir"/heads
 385
 386# TODO: This should possibly go, with the semantics that all positive given
 387#       refs are updated, and their original heads stored in refs/original/
 388# Filter tags
 389
 390if [ "$filter_tag_name" ]; then
 391        git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
 392        while read sha1 type ref; do
 393                ref="${ref#refs/tags/}"
 394                # XXX: Rewrite tagged trees as well?
 395                if [ "$type" != "commit" -a "$type" != "tag" ]; then
 396                        continue;
 397                fi
 398
 399                if [ "$type" = "tag" ]; then
 400                        # Dereference to a commit
 401                        sha1t="$sha1"
 402                        sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
 403                fi
 404
 405                [ -f "../map/$sha1" ] || continue
 406                new_sha1="$(cat "../map/$sha1")"
 407                GIT_COMMIT="$sha1"
 408                export GIT_COMMIT
 409                new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
 410                        die "tag name filter failed: $filter_tag_name"
 411
 412                echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 413
 414                if [ "$type" = "tag" ]; then
 415                        # Warn that we are not rewriting the tag object itself.
 416                        warn "unreferencing tag object $sha1t"
 417                fi
 418
 419                git update-ref "refs/tags/$new_ref" "$new_sha1" ||
 420                        die "Could not write tag $new_ref"
 421        done
 422fi
 423
 424cd ../..
 425rm -rf "$tempdir"
 426echo
 427test $count -gt 0 && echo "These refs were rewritten:"
 428git show-ref | grep ^"$orig_namespace"
 429
 430unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
 431test -z "$ORIG_GIT_DIR" || GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
 432test -z "$ORIG_GIT_WORK_TREE" || GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
 433        export GIT_WORK_TREE
 434test -z "$ORIG_GIT_INDEX_FILE" || GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
 435        export GIT_INDEX_FILE
 436git read-tree -u -m HEAD
 437
 438exit $ret