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=0.6
   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 # recurse_deps CMD NAME [BRANCHPATH...]
 130 # Recursively eval CMD on all dependencies of NAME.
 131 # CMD can refer to $_name for queried branch name,
 132 # $_dep for dependency name,
 133 # $_depchain for space-seperated branch backtrace,
 134 # and the $_dep_is_tgish boolean.
 135 # It can modify $_ret to affect the return value
 136 # of the whole function.
 137 # If recurse_deps() hits missing dependencies, it will append
 138 # them to space-separated $missing_deps list and skip them.
 139 recurse_deps()
 140 {
 141         _cmd="$1"; shift
 142         _name="$1"; # no shift
 143         _depchain="$*"
 144
 145         _depsfile="$(mktemp -t tg-depsfile.XXXXXX)"
 146         # Check also our base against remote base. Checking our head
 147         # against remote head has to be done in the helper.
 148         if has_remote "top-bases/$_name"; then
 149                 echo "refs/remotes/$base_remote/top-bases/$_name" >>"$_depsfile"
 150         fi
 151
 152         # if the branch was annihilated, there exists no .topdeps file
 153         if ! branch_annihilated "$_name"; then
 154                 #TODO: handle nonexisting .topdeps?
 155                 git cat-file blob "$_name:.topdeps" >>"$_depsfile";
 156         fi;
 157
 158         _ret=0
 159         while read _dep; do
 160                 if ! ref_exists "$_dep" ; then
 161                         # All hope is lost
 162                         missing_deps="$missing_deps $_dep"
 163                         continue
 164                 fi
 165
 166                 _dep_is_tgish=1
 167                 ref_exists "refs/top-bases/$_dep"  ||
 168                         _dep_is_tgish=
 169
 170                 # Shoo shoo, keep our environment alone!
 171                 [ -z "$_dep_is_tgish" ] ||
 172                         (recurse_deps "$_cmd" "$_dep" "$@") ||
 173                         _ret=$?
 174
 175                 eval "$_cmd"
 176         done <"$_depsfile"
 177         missing_deps="${missing_deps# }"
 178         rm "$_depsfile"
 179         return $_ret
 180 }
 181
 182 # branch_needs_update
 183 # This is a helper function for determining whether given branch
 184 # is up-to-date wrt. its dependencies. It expects input as if it
 185 # is called as a recurse_deps() helper.
 186 # In case the branch does need update, it will echo it together
 187 # with the branch backtrace on the output (see needs_update()
 188 # description for details) and set $_ret to non-zero.
 189 branch_needs_update()
 190 {
 191         _dep_base_update=
 192         if [ -n "$_dep_is_tgish" ]; then
 193                 if has_remote "$_dep"; then
 194                         branch_contains "$_dep" "refs/remotes/$base_remote/$_dep" || _dep_base_update=%
 195                 fi
 196                 # This can possibly override the remote check result;
 197                 # we want to sync with our base first
 198                 branch_contains "$_dep" "refs/top-bases/$_dep" || _dep_base_update=:
 199         fi
 200
 201         if [ -n "$_dep_base_update" ]; then
 202                 # _dep needs to be synced with its base/remote
 203                 echo "$_dep_base_update $_dep $_depchain"
 204                 _ret=1
 205         elif [ -n "$_name" ] && ! branch_contains "refs/top-bases/$_name" "$_dep"; then
 206                 # Some new commits in _dep
 207                 echo "$_dep $_depchain"
 208                 _ret=1
 209         fi
 210 }
 211
 212 # needs_update NAME
 213 # This function is recursive; it outputs reverse path from NAME
 214 # to the branch (e.g. B_DIRTY B1 B2 NAME), one path per line,
 215 # inner paths first. Innermost name can be ':' if the head is
 216 # not in sync with the base or '%' if the head is not in sync
 217 # with the remote (in this order of priority).
 218 # It will also return non-zero status if NAME needs update.
 219 # If needs_update() hits missing dependencies, it will append
 220 # them to space-separated $missing_deps list and skip them.
 221 needs_update()
 222 {
 223         recurse_deps branch_needs_update "$@"
 224 }
 225
 226 # branch_empty NAME
 227 branch_empty()
 228 {
 229         [ -z "$(git diff-tree "refs/top-bases/$1" "$1" | fgrep -v "     .top")" ]
 230 }
 231
 232 # switch_to_base NAME [SEED]
 233 switch_to_base()
 234 {
 235         _base="refs/top-bases/$1"; _seed="$2"
 236         # We have to do all the hard work ourselves :/
 237         # This is like git checkout -b "$_base" "$_seed"
 238         # (or just git checkout "$_base"),
 239         # but does not create a detached HEAD.
 240         git read-tree -u -m HEAD "${_seed:-$_base}"
 241         [ -z "$_seed" ] || git update-ref "$_base" "$_seed"
 242         git symbolic-ref HEAD "$_base"
 243 }
 244
 245 # Show the help messages.
 246 do_help()
 247 {
 248         if [ -z "$1" ] ; then
 249                 # This is currently invoked in all kinds of circumstances,
 250                 # including when the user made a usage error. Should we end up
 251                 # providing more than a short help message, then we should
 252                 # differentiate.
 253                 # Petr's comment: http://marc.info/?l=git&m=122718711327376&w=2
 254
 255                 ## Build available commands list for help output
 256
 257                 cmds=
 258                 sep=
 259                 for cmd in "@cmddir@"/tg-*; do
 260                         ! [ -r "$cmd" ] && continue
 261                         # strip directory part and "tg-" prefix
 262                         cmd="$(basename "$cmd")"
 263                         cmd="${cmd#tg-}"
 264                         cmds="$cmds$sep$cmd"
 265                         sep="|"
 266                 done
 267
 268                 echo "TopGit v$TG_VERSION - A different patch queue manager"
 269                 echo "Usage: tg [-r REMOTE] ($cmds|help) ..."
 270         elif [ -r "@cmddir@"/tg-$1 ] ; then
 271                 @cmddir@/tg-$1 -h || :
 272                 echo
 273                 if [ -r "@sharedir@/tg-$1.txt" ] ; then
 274                         cat "@sharedir@/tg-$1.txt"
 275                 fi
 276         else
 277                 echo "`basename $0`: no help for $1" 1>&2
 278                 do_help
 279                 exit 1
 280         fi
 281 }
 282
 283 ## Pager stuff
 284
 285 # isatty FD
 286 isatty()
 287 {
 288         test -t $1
 289 }
 290
 291 # setup_pager
 292 # Spawn pager process and redirect the rest of our output to it
 293 setup_pager()
 294 {
 295         isatty 1 || return 0
 296
 297         # TG_PAGER = GIT_PAGER | PAGER | less
 298         # NOTE: GIT_PAGER='' is significant
 299         TG_PAGER=${GIT_PAGER-${PAGER-less}}
 300
 301         [ -z "$TG_PAGER"  -o  "$TG_PAGER" = "cat" ]  && return 0
 302
 303
 304         # now spawn pager
 305         export LESS=${LESS:-FRSX}       # as in pager.c:pager_preexec()
 306
 307         _pager_fifo_dir="$(mktemp -t -d tg-pager-fifo.XXXXXX)"
 308         _pager_fifo="$_pager_fifo_dir/0"
 309         mkfifo -m 600 "$_pager_fifo"
 310
 311         "$TG_PAGER" < "$_pager_fifo" &
 312         exec > "$_pager_fifo"           # dup2(pager_fifo.in, 1)
 313
 314         # this is needed so e.g. `git diff` will still colorize it's output if
 315         # requested in ~/.gitconfig with color.diff=auto
 316         export GIT_PAGER_IN_USE=1
 317
 318         # atexit(close(1); wait pager)
 319         trap "exec >&-; rm \"$_pager_fifo\"; rmdir \"$_pager_fifo_dir\"; wait" EXIT
 320 }
 321
 322 ## Startup
 323
 324 [ -d "@cmddir@" ] ||
 325         die "No command directory: '@cmddir@'"
 326
 327 ## Initial setup
 328
 329 set -e
 330 git_dir="$(git rev-parse --git-dir)"
 331 root_dir="$(git rev-parse --show-cdup)"; root_dir="${root_dir:-.}"
 332 # Make sure root_dir doesn't end with a trailing slash.
 333 root_dir="${root_dir%/}"
 334 base_remote="$(git config topgit.remote 2>/dev/null)" || :
 335 tg="tg"
 336 # make sure merging the .top* files will always behave sanely
 337 setup_ours
 338 setup_hook "pre-commit"
 339
 340 ## Dispatch
 341
 342 # We were sourced from another script for our utility functions;
 343 # this is set by hooks.
 344 [ -z "$tg__include" ] || return 0
 345
 346 if [ "$1" = "-r" ]; then
 347         shift
 348         if [ -z "$1" ]; then
 349                 echo "Option -r requires an argument." >&2
 350                 do_help
 351                 exit 1
 352         fi
 353         base_remote="$1"; shift
 354         tg="$tg -r $base_remote"
 355 fi
 356
 357 cmd="$1"
 358 [ -n "$cmd" ] || { do_help; exit 1; }
 359 shift
 360
 361 case "$cmd" in
 362 help|--help|-h)
 363         do_help "$1"
 364         exit 0;;
 365 --hooks-path)
 366         # Internal command
 367         echo "@hooksdir@";;
 368 *)
 369         [ -r "@cmddir@"/tg-$cmd ] || {
 370                 echo "Unknown subcommand: $cmd" >&2
 371                 do_help
 372                 exit 1
 373         }
 374         . "@cmddir@"/tg-$cmd;;
 375 esac
 376
 377 # vim:noet