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