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 # 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 # remote dependencies are processed if no_remotes is unset.
 140 recurse_deps()
 141 {
 142         _cmd="$1"; shift
 143         _name="$1"; # no shift
 144         _depchain="$*"
 145
 146         _depsfile="$(mktemp -t tg-depsfile.XXXXXX)"
 147         # If no_remotes is unset check also our base against remote base.
 148         # Checking our head against remote head has to be done in the helper.
 149         if test -z "$no_remotes" && has_remote "top-bases/$_name"; then
 150                 echo "refs/remotes/$base_remote/top-bases/$_name" >>"$_depsfile"
 151         fi
 152
 153         # if the branch was annihilated, there exists no .topdeps file
 154         if ! branch_annihilated "$_name"; then
 155                 #TODO: handle nonexisting .topdeps?
 156                 git cat-file blob "$_name:.topdeps" >>"$_depsfile";
 157         fi;
 158
 159         _ret=0
 160         while read _dep; do
 161                 if ! ref_exists "$_dep" ; then
 162                         # All hope is lost
 163                         missing_deps="$missing_deps $_dep"
 164                         continue
 165                 fi
 166
 167                 _dep_is_tgish=1
 168                 ref_exists "refs/top-bases/$_dep"  ||
 169                         _dep_is_tgish=
 170
 171                 # Shoo shoo, keep our environment alone!
 172                 [ -z "$_dep_is_tgish" ] ||
 173                         (recurse_deps "$_cmd" "$_dep" "$@") ||
 174                         _ret=$?
 175
 176                 eval "$_cmd"
 177         done <"$_depsfile"
 178         missing_deps="${missing_deps# }"
 179         rm "$_depsfile"
 180         return $_ret
 181 }
 182
 183 # branch_needs_update
 184 # This is a helper function for determining whether given branch
 185 # is up-to-date wrt. its dependencies. It expects input as if it
 186 # is called as a recurse_deps() helper.
 187 # In case the branch does need update, it will echo it together
 188 # with the branch backtrace on the output (see needs_update()
 189 # description for details) and set $_ret to non-zero.
 190 branch_needs_update()
 191 {
 192         _dep_base_update=
 193         if [ -n "$_dep_is_tgish" ]; then
 194                 if has_remote "$_dep"; then
 195                         branch_contains "$_dep" "refs/remotes/$base_remote/$_dep" || _dep_base_update=%
 196                 fi
 197                 # This can possibly override the remote check result;
 198                 # we want to sync with our base first
 199                 branch_contains "$_dep" "refs/top-bases/$_dep" || _dep_base_update=:
 200         fi
 201
 202         if [ -n "$_dep_base_update" ]; then
 203                 # _dep needs to be synced with its base/remote
 204                 echo "$_dep_base_update $_dep $_depchain"
 205                 _ret=1
 206         elif [ -n "$_name" ] && ! branch_contains "refs/top-bases/$_name" "$_dep"; then
 207                 # Some new commits in _dep
 208                 echo "$_dep $_depchain"
 209                 _ret=1
 210         fi
 211 }
 212
 213 # needs_update NAME
 214 # This function is recursive; it outputs reverse path from NAME
 215 # to the branch (e.g. B_DIRTY B1 B2 NAME), one path per line,
 216 # inner paths first. Innermost name can be ':' if the head is
 217 # not in sync with the base or '%' if the head is not in sync
 218 # with the remote (in this order of priority).
 219 # It will also return non-zero status if NAME needs update.
 220 # If needs_update() hits missing dependencies, it will append
 221 # them to space-separated $missing_deps list and skip them.
 222 needs_update()
 223 {
 224         recurse_deps branch_needs_update "$@"
 225 }
 226
 227 # branch_empty NAME
 228 branch_empty()
 229 {
 230         [ -z "$(git diff-tree "refs/top-bases/$1" "$1" -- | fgrep -v "  .top")" ]
 231 }
 232
 233 # switch_to_base NAME [SEED]
 234 switch_to_base()
 235 {
 236         _base="refs/top-bases/$1"; _seed="$2"
 237         # We have to do all the hard work ourselves :/
 238         # This is like git checkout -b "$_base" "$_seed"
 239         # (or just git checkout "$_base"),
 240         # but does not create a detached HEAD.
 241         git read-tree -u -m HEAD "${_seed:-$_base}"
 242         [ -z "$_seed" ] || git update-ref "$_base" "$_seed"
 243         git symbolic-ref HEAD "$_base"
 244 }
 245
 246 # Show the help messages.
 247 do_help()
 248 {
 249         if [ -z "$1" ] ; then
 250                 # This is currently invoked in all kinds of circumstances,
 251                 # including when the user made a usage error. Should we end up
 252                 # providing more than a short help message, then we should
 253                 # differentiate.
 254                 # Petr's comment: http://marc.info/?l=git&m=122718711327376&w=2
 255
 256                 ## Build available commands list for help output
 257
 258                 cmds=
 259                 sep=
 260                 for cmd in "@cmddir@"/tg-*; do
 261                         ! [ -r "$cmd" ] && continue
 262                         # strip directory part and "tg-" prefix
 263                         cmd="$(basename "$cmd")"
 264                         cmd="${cmd#tg-}"
 265                         cmds="$cmds$sep$cmd"
 266                         sep="|"
 267                 done
 268
 269                 echo "TopGit v$TG_VERSION - A different patch queue manager"
 270                 echo "Usage: tg [-r REMOTE] ($cmds|help) ..."
 271         elif [ -r "@cmddir@"/tg-$1 ] ; then
 272                 setup_pager
 273                 @cmddir@/tg-$1 -h 2>&1 || :
 274                 echo
 275                 if [ -r "@sharedir@/tg-$1.txt" ] ; then
 276                         cat "@sharedir@/tg-$1.txt"
 277                 fi
 278         else
 279                 echo "`basename $0`: no help for $1" 1>&2
 280                 do_help
 281                 exit 1
 282         fi
 283 }
 284
 285 ## Pager stuff
 286
 287 # isatty FD
 288 isatty()
 289 {
 290         test -t $1
 291 }
 292
 293 # setup_pager
 294 # Spawn pager process and redirect the rest of our output to it
 295 setup_pager()
 296 {
 297         isatty 1 || return 0
 298
 299         # TG_PAGER = GIT_PAGER | PAGER | less
 300         # NOTE: GIT_PAGER='' is significant
 301         TG_PAGER=${GIT_PAGER-${PAGER-less}}
 302
 303         [ -z "$TG_PAGER"  -o  "$TG_PAGER" = "cat" ]  && return 0
 304
 305
 306         # now spawn pager
 307         export LESS=${LESS:-FRSX}       # as in pager.c:pager_preexec()
 308
 309         _pager_fifo_dir="$(mktemp -t -d tg-pager-fifo.XXXXXX)"
 310         _pager_fifo="$_pager_fifo_dir/0"
 311         mkfifo -m 600 "$_pager_fifo"
 312
 313         "$TG_PAGER" < "$_pager_fifo" &
 314         exec > "$_pager_fifo"           # dup2(pager_fifo.in, 1)
 315
 316         # this is needed so e.g. `git diff` will still colorize it's output if
 317         # requested in ~/.gitconfig with color.diff=auto
 318         export GIT_PAGER_IN_USE=1
 319
 320         # atexit(close(1); wait pager)
 321         trap "exec >&-; rm \"$_pager_fifo\"; rmdir \"$_pager_fifo_dir\"; wait" EXIT
 322 }
 323
 324 ## Startup
 325
 326 [ -d "@cmddir@" ] ||
 327         die "No command directory: '@cmddir@'"
 328
 329 ## Initial setup
 330
 331 set -e
 332 git_dir="$(git rev-parse --git-dir)"
 333 root_dir="$(git rev-parse --show-cdup)"; root_dir="${root_dir:-.}"
 334 # Make sure root_dir doesn't end with a trailing slash.
 335 root_dir="${root_dir%/}"
 336 base_remote="$(git config topgit.remote 2>/dev/null)" || :
 337 tg="tg"
 338 # make sure merging the .top* files will always behave sanely
 339 setup_ours
 340 setup_hook "pre-commit"
 341
 342 ## Dispatch
 343
 344 # We were sourced from another script for our utility functions;
 345 # this is set by hooks.  Skip the rest of the file.  A simple return doesn't
 346 # work as expected in every shell.  See http://bugs.debian.org/516188
 347 if [ -z "$tg__include" ]; then
 348
 349 if [ "$1" = "-r" ]; then
 350         shift
 351         if [ -z "$1" ]; then
 352                 echo "Option -r requires an argument." >&2
 353                 do_help
 354                 exit 1
 355         fi
 356         base_remote="$1"; shift
 357         tg="$tg -r $base_remote"
 358 fi
 359
 360 cmd="$1"
 361 [ -n "$cmd" ] || { do_help; exit 1; }
 362 shift
 363
 364 case "$cmd" in
 365 help|--help|-h)
 366         do_help "$1"
 367         exit 0;;
 368 --hooks-path)
 369         # Internal command
 370         echo "@hooksdir@";;
 371 *)
 372         [ -r "@cmddir@"/tg-$cmd ] || {
 373                 echo "Unknown subcommand: $cmd" >&2
 374                 do_help
 375                 exit 1
 376         }
 377         . "@cmddir@"/tg-$cmd;;
 378 esac
 379
 380 fi
 381
 382 # vim:noet