tg.sh

   1 #!/bin/sh
   2 # TopGit - A different patch queue manager
   3 # (c) Petr Baudis <pasky@suse.cz>  2008
   4 # GPLv2
   5
   6 TG_VERSION=0.8
   7
   8 ## Auxiliary functions
   9
  10 info()
  11 {
  12         echo "${TG_RECURSIVE}tg: $*"
  13 }
  14
  15 die()
  16 {
  17         info "fatal: $*" >&2
  18         exit 1
  19 }
  20
  21 # cat_file TOPIC:PATH [FROM]
  22 # cat the file PATH from branch TOPIC when FROM is empty.
  23 # FROM can be -i or -w, than the file will be from the index or worktree,
  24 # respectively. The caller should than ensure that HEAD is TOPIC, to make sense.
  25 cat_file()
  26 {
  27         path="$1"
  28         case "${2-}" in
  29         -w)
  30                 cat "$root_dir/${path#*:}"
  31                 ;;
  32         -i)
  33                 # ':file' means cat from index
  34                 git cat-file blob ":${path#*:}"
  35                 ;;
  36         '')
  37                 git cat-file blob "$path"
  38                 ;;
  39         *)
  40                 die "Wrong argument to cat_file: '$2'"
  41                 ;;
  42         esac
  43 }
  44
  45 # get tree for the committed topic
  46 get_tree_()
  47 {
  48         echo "$1"
  49 }
  50
  51 # get tree for the base
  52 get_tree_b()
  53 {
  54         echo "refs/top-bases/$1"
  55 }
  56
  57 # get tree for the index
  58 get_tree_i()
  59 {
  60         git write-tree
  61 }
  62
  63 # get tree for the worktree
  64 get_tree_w()
  65 {
  66         i_tree=$(git write-tree)
  67         (
  68                 # the file for --index-output needs to sit next to the
  69                 # current index file
  70                 : ${GIT_INDEX_FILE:="$git_dir/index"}
  71                 TMP_INDEX="$(mktemp "${GIT_INDEX_FILE}-tg.XXXXXX")"
  72                 git read-tree -m $i_tree --index-output="$TMP_INDEX" &&
  73                 GIT_INDEX_FILE="$TMP_INDEX" &&
  74                 export GIT_INDEX_FILE &&
  75                 git diff --name-only -z HEAD |
  76                         git update-index -z --add --remove --stdin &&
  77                 git write-tree &&
  78                 rm -f "$TMP_INDEX"
  79         )
  80 }
  81
  82 # pretty_tree NAME [-b | -i | -w]
  83 # Output tree ID of a cleaned-up tree without tg's artifacts.
  84 # NAME will be ignored for -i and -w, but needs to be present
  85 pretty_tree()
  86 {
  87         name=$1
  88         source=${2#?}
  89         git ls-tree --full-tree "$(get_tree_$source "$name")" |
  90                 awk -F '        ' '$2 !~ /^.top/' |
  91                 git mktree
  92 }
  93
  94 # setup_hook NAME
  95 setup_hook()
  96 {
  97         hook_call="\"\$($tg --hooks-path)\"/$1 \"\$@\""
  98         if [ -f "$git_dir/hooks/$1" ] &&
  99            fgrep -q "$hook_call" "$git_dir/hooks/$1"; then
 100                 # Another job well done!
 101                 return
 102         fi
 103         # Prepare incantation
 104         if [ -x "$git_dir/hooks/$1" ]; then
 105                 hook_call="$hook_call"' || exit $?'
 106         else
 107                 hook_call="exec $hook_call"
 108         fi
 109         # Don't call hook if tg is not installed
 110         hook_call="if which \"$tg\" > /dev/null; then $hook_call; fi"
 111         # Insert call into the hook
 112         {
 113                 echo "#!/bin/sh"
 114                 echo "$hook_call"
 115                 [ ! -s "$git_dir/hooks/$1" ] || cat "$git_dir/hooks/$1"
 116         } >"$git_dir/hooks/$1+"
 117         chmod a+x "$git_dir/hooks/$1+"
 118         mv "$git_dir/hooks/$1+" "$git_dir/hooks/$1"
 119 }
 120
 121 # setup_ours (no arguments)
 122 setup_ours()
 123 {
 124         if [ ! -s "$git_dir/info/attributes" ] || ! grep -q topmsg "$git_dir/info/attributes"; then
 125                 {
 126                         echo ".topmsg   merge=ours"
 127                         echo ".topdeps  merge=ours"
 128                 } >>"$git_dir/info/attributes"
 129         fi
 130         if ! git config merge.ours.driver >/dev/null; then
 131                 git config merge.ours.name '"always keep ours" merge driver'
 132                 git config merge.ours.driver 'touch %A'
 133         fi
 134 }
 135
 136 # measure_branch NAME [BASE]
 137 measure_branch()
 138 {
 139         _bname="$1"; _base="$2"
 140         [ -n "$_base" ] || _base="refs/top-bases/$_bname"
 141         # The caller should've verified $name is valid
 142         _commits="$(git rev-list "$_bname" ^"$_base" -- | wc -l)"
 143         _nmcommits="$(git rev-list --no-merges "$_bname" ^"$_base" -- | wc -l)"
 144         if [ $_commits -gt 1 ]; then
 145                 _suffix="commits"
 146         else
 147                 _suffix="commit"
 148         fi
 149         echo "$_commits/$_nmcommits $_suffix"
 150 }
 151
 152 # branch_contains B1 B2
 153 # Whether B1 is a superset of B2.
 154 branch_contains()
 155 {
 156         [ -z "$(git rev-list --max-count=1 ^"$1" "$2" --)" ]
 157 }
 158
 159 # ref_exists REF
 160 # Whether REF is a valid ref name
 161 ref_exists()
 162 {
 163         git rev-parse --verify "$@" >/dev/null 2>&1
 164 }
 165
 166 # has_remote BRANCH
 167 # Whether BRANCH has a remote equivalent (accepts top-bases/ too)
 168 has_remote()
 169 {
 170         [ -n "$base_remote" ] && ref_exists "remotes/$base_remote/$1"
 171 }
 172
 173 branch_annihilated()
 174 {
 175         _name="$1";
 176
 177         # use the merge base in case the base is ahead.
 178         mb="$(git merge-base "refs/top-bases/$_name" "$_name")";
 179
 180         test "$(git rev-parse "$mb^{tree}")" = "$(git rev-parse "$_name^{tree}")";
 181 }
 182
 183 # is_sha1 REF
 184 # Whether REF is a SHA1 (compared to a symbolic name).
 185 is_sha1()
 186 {
 187         [ "$(git rev-parse "$1")" = "$1" ]
 188 }
 189
 190 # recurse_deps CMD NAME [BRANCHPATH...]
 191 # Recursively eval CMD on all dependencies of NAME.
 192 # CMD can refer to $_name for queried branch name,
 193 # $_dep for dependency name,
 194 # $_depchain for space-seperated branch backtrace,
 195 # and the $_dep_is_tgish boolean.
 196 # It can modify $_ret to affect the return value
 197 # of the whole function.
 198 # If recurse_deps() hits missing dependencies, it will append
 199 # them to space-separated $missing_deps list and skip them.
 200 # remote dependencies are processed if no_remotes is unset.
 201 recurse_deps()
 202 {
 203         _cmd="$1"; shift
 204         _name="$1"; # no shift
 205         _depchain="$*"
 206
 207         _depsfile="$(get_temp tg-depsfile)"
 208         # If no_remotes is unset check also our base against remote base.
 209         # Checking our head against remote head has to be done in the helper.
 210         if test -z "$no_remotes" && has_remote "top-bases/$_name"; then
 211                 echo "refs/remotes/$base_remote/top-bases/$_name" >>"$_depsfile"
 212         fi
 213
 214         # if the branch was annihilated, there exists no .topdeps file
 215         if ! branch_annihilated "$_name"; then
 216                 #TODO: handle nonexisting .topdeps?
 217                 git cat-file blob "$_name:.topdeps" >>"$_depsfile";
 218         fi;
 219
 220         _ret=0
 221         while read _dep; do
 222                 if ! ref_exists "$_dep" ; then
 223                         # All hope is lost
 224                         missing_deps="$missing_deps $_dep"
 225                         continue
 226                 fi
 227
 228                 _dep_is_tgish=1
 229                 ref_exists "refs/top-bases/$_dep"  ||
 230                         _dep_is_tgish=
 231
 232                 # Shoo shoo, keep our environment alone!
 233                 [ -z "$_dep_is_tgish" ] ||
 234                         (recurse_deps "$_cmd" "$_dep" "$@") ||
 235                         _ret=$?
 236
 237                 eval "$_cmd"
 238         done <"$_depsfile"
 239         missing_deps="${missing_deps# }"
 240         return $_ret
 241 }
 242
 243 # branch_needs_update
 244 # This is a helper function for determining whether given branch
 245 # is up-to-date wrt. its dependencies. It expects input as if it
 246 # is called as a recurse_deps() helper.
 247 # In case the branch does need update, it will echo it together
 248 # with the branch backtrace on the output (see needs_update()
 249 # description for details) and set $_ret to non-zero.
 250 branch_needs_update()
 251 {
 252         _dep_base_update=
 253         if [ -n "$_dep_is_tgish" ]; then
 254                 if has_remote "$_dep"; then
 255                         branch_contains "$_dep" "refs/remotes/$base_remote/$_dep" || _dep_base_update=%
 256                 fi
 257                 # This can possibly override the remote check result;
 258                 # we want to sync with our base first
 259                 branch_contains "$_dep" "refs/top-bases/$_dep" || _dep_base_update=:
 260         fi
 261
 262         if [ -n "$_dep_base_update" ]; then
 263                 # _dep needs to be synced with its base/remote
 264                 echo "$_dep_base_update $_dep $_depchain"
 265                 _ret=1
 266         elif [ -n "$_name" ] && ! branch_contains "refs/top-bases/$_name" "$_dep"; then
 267                 # Some new commits in _dep
 268                 echo "$_dep $_depchain"
 269                 _ret=1
 270         fi
 271 }
 272
 273 # needs_update NAME
 274 # This function is recursive; it outputs reverse path from NAME
 275 # to the branch (e.g. B_DIRTY B1 B2 NAME), one path per line,
 276 # inner paths first. Innermost name can be ':' if the head is
 277 # not in sync with the base or '%' if the head is not in sync
 278 # with the remote (in this order of priority).
 279 # It will also return non-zero status if NAME needs update.
 280 # If needs_update() hits missing dependencies, it will append
 281 # them to space-separated $missing_deps list and skip them.
 282 needs_update()
 283 {
 284         recurse_deps branch_needs_update "$@"
 285 }
 286
 287 # branch_empty NAME [-i | -w]
 288 branch_empty()
 289 {
 290         [ "$(pretty_tree "$1" -b)" = "$(pretty_tree "$1" ${2-})" ]
 291 }
 292
 293 # list_deps [-i | -w]
 294 # -i/-w apply only to HEAD
 295 list_deps()
 296 {
 297         local head
 298         local head_from
 299         local from
 300         head_from=${1-}
 301         head="$(git symbolic-ref -q HEAD)" ||
 302                 head="..detached.."
 303
 304         git for-each-ref refs/top-bases |
 305                 while read rev type ref; do
 306                         name="${ref#refs/top-bases/}"
 307                         if branch_annihilated "$name"; then
 308                                 continue;
 309                         fi
 310
 311                         from=$head_from
 312                         [ "refs/heads/$name" = "$head" ] ||
 313                                 from=
 314                         cat_file "$name:.topdeps" $from | while read dep; do
 315                                 dep_is_tgish=true
 316                                 ref_exists "refs/top-bases/$dep"  ||
 317                                         dep_is_tgish=false
 318                                 if ! "$dep_is_tgish" || ! branch_annihilated $dep; then
 319                                         echo "$name $dep"
 320                                 fi
 321                         done
 322                 done
 323 }
 324
 325 # switch_to_base NAME [SEED]
 326 switch_to_base()
 327 {
 328         _base="refs/top-bases/$1"; _seed="$2"
 329         # We have to do all the hard work ourselves :/
 330         # This is like git checkout -b "$_base" "$_seed"
 331         # (or just git checkout "$_base"),
 332         # but does not create a detached HEAD.
 333         git read-tree -u -m HEAD "${_seed:-$_base}"
 334         [ -z "$_seed" ] || git update-ref "$_base" "$_seed"
 335         git symbolic-ref HEAD "$_base"
 336 }
 337
 338 # Show the help messages.
 339 do_help()
 340 {
 341         if [ -z "$1" ] ; then
 342                 # This is currently invoked in all kinds of circumstances,
 343                 # including when the user made a usage error. Should we end up
 344                 # providing more than a short help message, then we should
 345                 # differentiate.
 346                 # Petr's comment: http://marc.info/?l=git&m=122718711327376&w=2
 347
 348                 ## Build available commands list for help output
 349
 350                 cmds=
 351                 sep=
 352                 for cmd in "@cmddir@"/tg-*; do
 353                         ! [ -r "$cmd" ] && continue
 354                         # strip directory part and "tg-" prefix
 355                         cmd="$(basename "$cmd")"
 356                         cmd="${cmd#tg-}"
 357                         cmds="$cmds$sep$cmd"
 358                         sep="|"
 359                 done
 360
 361                 echo "TopGit v$TG_VERSION - A different patch queue manager"
 362                 echo "Usage: tg [-r REMOTE] ($cmds|help) ..."
 363         elif [ -r "@cmddir@"/tg-$1 ] ; then
 364                 setup_pager
 365                 @cmddir@/tg-$1 -h 2>&1 || :
 366                 echo
 367                 if [ -r "@sharedir@/tg-$1.txt" ] ; then
 368                         cat "@sharedir@/tg-$1.txt"
 369                 fi
 370         else
 371                 echo "`basename $0`: no help for $1" 1>&2
 372                 do_help
 373                 exit 1
 374         fi
 375 }
 376
 377 ## Pager stuff
 378
 379 # isatty FD
 380 isatty()
 381 {
 382         test -t $1
 383 }
 384
 385 # setup_pager
 386 # Spawn pager process and redirect the rest of our output to it
 387 setup_pager()
 388 {
 389         isatty 1 || return 0
 390
 391         # TG_PAGER = GIT_PAGER | PAGER | less
 392         # NOTE: GIT_PAGER='' is significant
 393         TG_PAGER=${GIT_PAGER-${PAGER-less}}
 394
 395         [ -z "$TG_PAGER"  -o  "$TG_PAGER" = "cat" ]  && return 0
 396
 397
 398         # now spawn pager
 399         export LESS="${LESS:-FRSX}"     # as in pager.c:pager_preexec()
 400
 401         # setup_pager should be called only once per command
 402         pager_fifo="$tg_tmp_dir/pager"
 403         mkfifo -m 600 "$pager_fifo"
 404
 405         "$TG_PAGER" < "$pager_fifo" &
 406         exec > "$pager_fifo"            # dup2(pager_fifo.in, 1)
 407
 408         # this is needed so e.g. `git diff` will still colorize it's output if
 409         # requested in ~/.gitconfig with color.diff=auto
 410         export GIT_PAGER_IN_USE=1
 411
 412         # atexit(close(1); wait pager)
 413         # deliberately overwrites the global EXIT trap
 414         trap "exec >&-; rm -rf \"$tg_tmp_dir\"; wait" EXIT
 415 }
 416
 417 # get_temp NAME [-d]
 418 # creates a new temporary file (or directory with -d) in the global
 419 # temporary directory $tg_tmp_dir with pattern prefix NAME
 420 get_temp()
 421 {
 422         mktemp ${2-} "$tg_tmp_dir/$1.XXXXXX"
 423 }
 424
 425 ## Startup
 426
 427 [ -d "@cmddir@" ] ||
 428         die "No command directory: '@cmddir@'"
 429
 430 ## Initial setup
 431
 432 set -e
 433 git_dir="$(git rev-parse --git-dir)"
 434 root_dir="$(git rev-parse --show-cdup)"; root_dir="${root_dir:-.}"
 435 # Make sure root_dir doesn't end with a trailing slash.
 436 root_dir="${root_dir%/}"
 437 base_remote="$(git config topgit.remote 2>/dev/null)" || :
 438 tg="tg"
 439 # make sure merging the .top* files will always behave sanely
 440 setup_ours
 441 setup_hook "pre-commit"
 442 # create global temporary directories, inside GIT_DIR
 443 tg_tmp_dir="$(mktemp -d "$git_dir/tg-tmp.XXXXXX")"
 444 trap "rm -rf \"$tg_tmp_dir\"" EXIT
 445
 446 ## Dispatch
 447
 448 # We were sourced from another script for our utility functions;
 449 # this is set by hooks.  Skip the rest of the file.  A simple return doesn't
 450 # work as expected in every shell.  See http://bugs.debian.org/516188
 451 if [ -z "$tg__include" ]; then
 452
 453 if [ "$1" = "-r" ]; then
 454         shift
 455         if [ -z "$1" ]; then
 456                 echo "Option -r requires an argument." >&2
 457                 do_help
 458                 exit 1
 459         fi
 460         base_remote="$1"; shift
 461         tg="$tg -r $base_remote"
 462 fi
 463
 464 cmd="$1"
 465 [ -n "$cmd" ] || { do_help; exit 1; }
 466 shift
 467
 468 case "$cmd" in
 469 help|--help|-h)
 470         do_help "$1"
 471         exit 0;;
 472 --hooks-path)
 473         # Internal command
 474         echo "@hooksdir@";;
 475 *)
 476         [ -r "@cmddir@"/tg-$cmd ] || {
 477                 echo "Unknown subcommand: $cmd" >&2
 478                 do_help
 479                 exit 1
 480         }
 481         . "@cmddir@"/tg-$cmd;;
 482 esac
 483
 484 fi
 485
 486 # vim:noet