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