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: $*"
  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                 arg=$(echo "$arg" | tail --bytes=+5)
  29                 cat "$arg"
  30                 return
  31                 ;;
  32         '(i):'*)
  33                 # ':file' means cat from index
  34                 arg=$(echo "$arg" | tail --bytes=+5)
  35                 git cat-file blob ":$arg"
  36                 ;;
  37         *)
  38                 git cat-file blob "$arg"
  39         esac
  40 }
  41
  42 # setup_hook NAME
  43 setup_hook()
  44 {
  45         hook_call="\"\$($tg --hooks-path)\"/$1 \"\$@\""
  46         if [ -f "$git_dir/hooks/$1" ] &&
  47            fgrep -q "$hook_call" "$git_dir/hooks/$1"; then
  48                 # Another job well done!
  49                 return
  50         fi
  51         # Prepare incantation
  52         if [ -x "$git_dir/hooks/$1" ]; then
  53                 hook_call="$hook_call"' || exit $?'
  54         else
  55                 hook_call="exec $hook_call"
  56         fi
  57         # Insert call into the hook
  58         {
  59                 echo "#!/bin/sh"
  60                 echo "$hook_call"
  61                 [ ! -s "$git_dir/hooks/$1" ] || cat "$git_dir/hooks/$1"
  62         } >"$git_dir/hooks/$1+"
  63         chmod a+x "$git_dir/hooks/$1+"
  64         mv "$git_dir/hooks/$1+" "$git_dir/hooks/$1"
  65 }
  66
  67 # setup_ours (no arguments)
  68 setup_ours()
  69 {
  70         if [ ! -s "$git_dir/info/attributes" ] || ! grep -q topmsg "$git_dir/info/attributes"; then
  71                 {
  72                         echo ".topmsg   merge=ours"
  73                         echo ".topdeps  merge=ours"
  74                 } >>"$git_dir/info/attributes"
  75         fi
  76         if ! git config merge.ours.driver >/dev/null; then
  77                 git config merge.ours.name '"always keep ours" merge driver'
  78                 git config merge.ours.driver 'touch %A'
  79         fi
  80 }
  81
  82 # measure_branch NAME [BASE]
  83 measure_branch()
  84 {
  85         _bname="$1"; _base="$2"
  86         [ -n "$_base" ] || _base="refs/top-bases/$_bname"
  87         # The caller should've verified $name is valid
  88         _commits="$(git rev-list "$_bname" ^"$_base" -- | wc -l)"
  89         _nmcommits="$(git rev-list --no-merges "$_bname" ^"$_base" -- | wc -l)"
  90         if [ $_commits -gt 1 ]; then
  91                 _suffix="commits"
  92         else
  93                 _suffix="commit"
  94         fi
  95         echo "$_commits/$_nmcommits $_suffix"
  96 }
  97
  98 # branch_contains B1 B2
  99 # Whether B1 is a superset of B2.
 100 branch_contains()
 101 {
 102         [ -z "$(git rev-list --max-count=1 ^"$1" "$2" --)" ]
 103 }
 104
 105 # ref_exists REF
 106 # Whether REF is a valid ref name
 107 ref_exists()
 108 {
 109         git rev-parse --verify "$@" >/dev/null 2>&1
 110 }
 111
 112 # has_remote BRANCH
 113 # Whether BRANCH has a remote equivalent (accepts top-bases/ too)
 114 has_remote()
 115 {
 116         [ -n "$base_remote" ] && ref_exists "remotes/$base_remote/$1"
 117 }
 118
 119 branch_annihilated()
 120 {
 121         _name="$1";
 122
 123         # use the merge base in case the base is ahead.
 124         mb="$(git merge-base "refs/top-bases/$_name" "$_name")";
 125
 126         test "$(git rev-parse "$mb^{tree}")" = "$(git rev-parse "$_name^{tree}")";
 127 }
 128
 129 # is_sha1 REF
 130 # Whether REF is a SHA1 (compared to a symbolic name).
 131 is_sha1()
 132 {
 133         [ "$(git rev-parse "$1")" = "$1" ]
 134 }
 135
 136 # recurse_deps CMD NAME [BRANCHPATH...]
 137 # Recursively eval CMD on all dependencies of NAME.
 138 # CMD can refer to $_name for queried branch name,
 139 # $_dep for dependency name,
 140 # $_depchain for space-seperated branch backtrace,
 141 # and the $_dep_is_tgish boolean.
 142 # It can modify $_ret to affect the return value
 143 # of the whole function.
 144 # If recurse_deps() hits missing dependencies, it will append
 145 # them to space-separated $missing_deps list and skip them.
 146 # remote dependencies are processed if no_remotes is unset.
 147 recurse_deps()
 148 {
 149         _cmd="$1"; shift
 150         _name="$1"; # no shift
 151         _depchain="$*"
 152
 153         _depsfile="$(mktemp -t tg-depsfile.XXXXXX)"
 154         # If no_remotes is unset check also our base against remote base.
 155         # Checking our head against remote head has to be done in the helper.
 156         if test -z "$no_remotes" && has_remote "top-bases/$_name"; then
 157                 echo "refs/remotes/$base_remote/top-bases/$_name" >>"$_depsfile"
 158         fi
 159
 160         # if the branch was annihilated, there exists no .topdeps file
 161         if ! branch_annihilated "$_name"; then
 162                 #TODO: handle nonexisting .topdeps?
 163                 git cat-file blob "$_name:.topdeps" >>"$_depsfile";
 164         fi;
 165
 166         _ret=0
 167         while read _dep; do
 168                 if ! ref_exists "$_dep" ; then
 169                         # All hope is lost
 170                         missing_deps="$missing_deps $_dep"
 171                         continue
 172                 fi
 173
 174                 _dep_is_tgish=1
 175                 ref_exists "refs/top-bases/$_dep"  ||
 176                         _dep_is_tgish=
 177
 178                 # Shoo shoo, keep our environment alone!
 179                 [ -z "$_dep_is_tgish" ] ||
 180                         (recurse_deps "$_cmd" "$_dep" "$@") ||
 181                         _ret=$?
 182
 183                 eval "$_cmd"
 184         done <"$_depsfile"
 185         missing_deps="${missing_deps# }"
 186         rm "$_depsfile"
 187         return $_ret
 188 }
 189
 190 # branch_needs_update
 191 # This is a helper function for determining whether given branch
 192 # is up-to-date wrt. its dependencies. It expects input as if it
 193 # is called as a recurse_deps() helper.
 194 # In case the branch does need update, it will echo it together
 195 # with the branch backtrace on the output (see needs_update()
 196 # description for details) and set $_ret to non-zero.
 197 branch_needs_update()
 198 {
 199         _dep_base_update=
 200         if [ -n "$_dep_is_tgish" ]; then
 201                 if has_remote "$_dep"; then
 202                         branch_contains "$_dep" "refs/remotes/$base_remote/$_dep" || _dep_base_update=%
 203                 fi
 204                 # This can possibly override the remote check result;
 205                 # we want to sync with our base first
 206                 branch_contains "$_dep" "refs/top-bases/$_dep" || _dep_base_update=:
 207         fi
 208
 209         if [ -n "$_dep_base_update" ]; then
 210                 # _dep needs to be synced with its base/remote
 211                 echo "$_dep_base_update $_dep $_depchain"
 212                 _ret=1
 213         elif [ -n "$_name" ] && ! branch_contains "refs/top-bases/$_name" "$_dep"; then
 214                 # Some new commits in _dep
 215                 echo "$_dep $_depchain"
 216                 _ret=1
 217         fi
 218 }
 219
 220 # needs_update NAME
 221 # This function is recursive; it outputs reverse path from NAME
 222 # to the branch (e.g. B_DIRTY B1 B2 NAME), one path per line,
 223 # inner paths first. Innermost name can be ':' if the head is
 224 # not in sync with the base or '%' if the head is not in sync
 225 # with the remote (in this order of priority).
 226 # It will also return non-zero status if NAME needs update.
 227 # If needs_update() hits missing dependencies, it will append
 228 # them to space-separated $missing_deps list and skip them.
 229 needs_update()
 230 {
 231         recurse_deps branch_needs_update "$@"
 232 }
 233
 234 # branch_empty NAME
 235 branch_empty()
 236 {
 237         [ -z "$(git diff-tree "refs/top-bases/$1" "$1" -- | fgrep -v "  .top")" ]
 238 }
 239
 240 # switch_to_base NAME [SEED]
 241 switch_to_base()
 242 {
 243         _base="refs/top-bases/$1"; _seed="$2"
 244         # We have to do all the hard work ourselves :/
 245         # This is like git checkout -b "$_base" "$_seed"
 246         # (or just git checkout "$_base"),
 247         # but does not create a detached HEAD.
 248         git read-tree -u -m HEAD "${_seed:-$_base}"
 249         [ -z "$_seed" ] || git update-ref "$_base" "$_seed"
 250         git symbolic-ref HEAD "$_base"
 251 }
 252
 253 # Show the help messages.
 254 do_help()
 255 {
 256         if [ -z "$1" ] ; then
 257                 # This is currently invoked in all kinds of circumstances,
 258                 # including when the user made a usage error. Should we end up
 259                 # providing more than a short help message, then we should
 260                 # differentiate.
 261                 # Petr's comment: http://marc.info/?l=git&m=122718711327376&w=2
 262
 263                 ## Build available commands list for help output
 264
 265                 cmds=
 266                 sep=
 267                 for cmd in "@cmddir@"/tg-*; do
 268                         ! [ -r "$cmd" ] && continue
 269                         # strip directory part and "tg-" prefix
 270                         cmd="$(basename "$cmd")"
 271                         cmd="${cmd#tg-}"
 272                         cmds="$cmds$sep$cmd"
 273                         sep="|"
 274                 done
 275
 276                 echo "TopGit v$TG_VERSION - A different patch queue manager"
 277                 echo "Usage: tg [-r REMOTE] ($cmds|help) ..."
 278         elif [ -r "@cmddir@"/tg-$1 ] ; then
 279                 setup_pager
 280                 @cmddir@/tg-$1 -h 2>&1 || :
 281                 echo
 282                 if [ -r "@sharedir@/tg-$1.txt" ] ; then
 283                         cat "@sharedir@/tg-$1.txt"
 284                 fi
 285         else
 286                 echo "`basename $0`: no help for $1" 1>&2
 287                 do_help
 288                 exit 1
 289         fi
 290 }
 291
 292 ## Pager stuff
 293
 294 # isatty FD
 295 isatty()
 296 {
 297         test -t $1
 298 }
 299
 300 # setup_pager
 301 # Spawn pager process and redirect the rest of our output to it
 302 setup_pager()
 303 {
 304         isatty 1 || return 0
 305
 306         # TG_PAGER = GIT_PAGER | PAGER | less
 307         # NOTE: GIT_PAGER='' is significant
 308         TG_PAGER=${GIT_PAGER-${PAGER-less}}
 309
 310         [ -z "$TG_PAGER"  -o  "$TG_PAGER" = "cat" ]  && return 0
 311
 312
 313         # now spawn pager
 314         export LESS="${LESS:-FRSX}"     # as in pager.c:pager_preexec()
 315
 316         _pager_fifo_dir="$(mktemp -t -d tg-pager-fifo.XXXXXX)"
 317         _pager_fifo="$_pager_fifo_dir/0"
 318         mkfifo -m 600 "$_pager_fifo"
 319
 320         "$TG_PAGER" < "$_pager_fifo" &
 321         exec > "$_pager_fifo"           # dup2(pager_fifo.in, 1)
 322
 323         # this is needed so e.g. `git diff` will still colorize it's output if
 324         # requested in ~/.gitconfig with color.diff=auto
 325         export GIT_PAGER_IN_USE=1
 326
 327         # atexit(close(1); wait pager)
 328         trap "exec >&-; rm \"$_pager_fifo\"; rmdir \"$_pager_fifo_dir\"; wait" EXIT
 329 }
 330
 331 ## Startup
 332
 333 [ -d "@cmddir@" ] ||
 334         die "No command directory: '@cmddir@'"
 335
 336 ## Initial setup
 337
 338 set -e
 339 git_dir="$(git rev-parse --git-dir)"
 340 root_dir="$(git rev-parse --show-cdup)"; root_dir="${root_dir:-.}"
 341 # Make sure root_dir doesn't end with a trailing slash.
 342 root_dir="${root_dir%/}"
 343 base_remote="$(git config topgit.remote 2>/dev/null)" || :
 344 tg="tg"
 345 # make sure merging the .top* files will always behave sanely
 346 setup_ours
 347 setup_hook "pre-commit"
 348
 349 ## Dispatch
 350
 351 # We were sourced from another script for our utility functions;
 352 # this is set by hooks.  Skip the rest of the file.  A simple return doesn't
 353 # work as expected in every shell.  See http://bugs.debian.org/516188
 354 if [ -z "$tg__include" ]; then
 355
 356 if [ "$1" = "-r" ]; then
 357         shift
 358         if [ -z "$1" ]; then
 359                 echo "Option -r requires an argument." >&2
 360                 do_help
 361                 exit 1
 362         fi
 363         base_remote="$1"; shift
 364         tg="$tg -r $base_remote"
 365 fi
 366
 367 cmd="$1"
 368 [ -n "$cmd" ] || { do_help; exit 1; }
 369 shift
 370
 371 case "$cmd" in
 372 help|--help|-h)
 373         do_help "$1"
 374         exit 0;;
 375 --hooks-path)
 376         # Internal command
 377         echo "@hooksdir@";;
 378 *)
 379         [ -r "@cmddir@"/tg-$cmd ] || {
 380                 echo "Unknown subcommand: $cmd" >&2
 381                 do_help
 382                 exit 1
 383         }
 384         . "@cmddir@"/tg-$cmd;;
 385 esac
 386
 387 fi
 388
 389 # vim:noet