tg.sh

   1 #!/bin/sh
   2 # TopGit - A different patch queue manager
   3 # (c) Petr Baudis <pasky@suse.cz>  2008
   4 # GPLv2
   5
   6
   7 ## Auxiliary functions
   8
   9 info()
  10 {
  11         echo "${TG_RECURSIVE}tg: $*"
  12 }
  13
  14 die()
  15 {
  16         info "fatal: $*"
  17         exit 1
  18 }
  19
  20 # setup_hook NAME
  21 setup_hook()
  22 {
  23         hook_call="\"\$($tg --hooks-path)\"/$1 \"\$@\""
  24         if [ -f "$git_dir/hooks/$1" ] &&
  25            fgrep -q "$hook_call" "$git_dir/hooks/$1"; then
  26                 # Another job well done!
  27                 return
  28         fi
  29         # Prepare incantation
  30         if [ -x "$git_dir/hooks/$1" ]; then
  31                 hook_call="$hook_call"' || exit $?'
  32         else
  33                 hook_call="exec $hook_call"
  34         fi
  35         # Insert call into the hook
  36         {
  37                 echo "#!/bin/sh"
  38                 echo "$hook_call"
  39                 [ ! -s "$git_dir/hooks/$1" ] || cat "$git_dir/hooks/$1"
  40         } >"$git_dir/hooks/$1+"
  41         chmod a+x "$git_dir/hooks/$1+"
  42         mv "$git_dir/hooks/$1+" "$git_dir/hooks/$1"
  43 }
  44
  45 # setup_ours (no arguments)
  46 setup_ours()
  47 {
  48         if [ ! -s "$git_dir/info/attributes" ] || ! grep -q topmsg "$git_dir/info/attributes"; then
  49                 {
  50                         echo ".topmsg   merge=ours"
  51                         echo ".topdeps  merge=ours"
  52                 } >>"$git_dir/info/attributes"
  53         fi
  54         if ! git config merge.ours.driver >/dev/null; then
  55                 git config merge.ours.name '"always keep ours" merge driver'
  56                 git config merge.ours.driver 'touch %A'
  57         fi
  58 }
  59
  60 # measure_branch NAME [BASE]
  61 measure_branch()
  62 {
  63         _bname="$1"; _base="$2"
  64         [ -n "$_base" ] || _base="refs/top-bases/$_bname"
  65         # The caller should've verified $name is valid
  66         _commits="$(git rev-list "$_bname" ^"$_base" -- | wc -l)"
  67         _nmcommits="$(git rev-list --no-merges "$_bname" ^"$_base" -- | wc -l)"
  68         if [ $_commits -gt 1 ]; then
  69                 _suffix="commits"
  70         else
  71                 _suffix="commit"
  72         fi
  73         echo "$_commits/$_nmcommits $_suffix"
  74 }
  75
  76 # branch_contains B1 B2
  77 # Whether B1 is a superset of B2.
  78 branch_contains()
  79 {
  80         [ -z "$(git rev-list --max-count=1 ^"$1" "$2" --)" ]
  81 }
  82
  83 # ref_exists REF
  84 # Whether REF is a valid ref name
  85 ref_exists()
  86 {
  87         git rev-parse --verify "$@" >/dev/null 2>&1
  88 }
  89
  90 # has_remote BRANCH
  91 # Whether BRANCH has a remote equivalent (accepts top-bases/ too)
  92 has_remote()
  93 {
  94         [ -n "$base_remote" ] && ref_exists "remotes/$base_remote/$1"
  95 }
  96
  97 branch_annihilated()
  98 {
  99         _name="$1";
 100
 101         # use the merge base in case the base is ahead.
 102         mb="$(git merge-base "refs/top-bases/$_name" "$_name")";
 103
 104         test "$(git rev-parse "$mb^{tree}")" = "$(git rev-parse "$_name^{tree}")";
 105 }
 106
 107 # recurse_deps CMD NAME [BRANCHPATH...]
 108 # Recursively eval CMD on all dependencies of NAME.
 109 # CMD can refer to $_name for queried branch name,
 110 # $_dep for dependency name,
 111 # $_depchain for space-seperated branch backtrace,
 112 # and the $_dep_is_tgish boolean.
 113 # It can modify $_ret to affect the return value
 114 # of the whole function.
 115 # If recurse_deps() hits missing dependencies, it will append
 116 # them to space-separated $missing_deps list and skip them.
 117 recurse_deps()
 118 {
 119         _cmd="$1"; shift
 120         _name="$1"; # no shift
 121         _depchain="$*"
 122
 123         _depsfile="$(mktemp -t tg-depsfile.XXXXXX)"
 124         # Check also our base against remote base. Checking our head
 125         # against remote head has to be done in the helper.
 126         if has_remote "top-bases/$_name"; then
 127                 echo "refs/remotes/$base_remote/top-bases/$_name" >>"$_depsfile"
 128         fi
 129
 130         # if the branch was annihilated, there exists no .topdeps file
 131         if ! branch_annihilated "$_name"; then
 132                 #TODO: handle nonexisting .topdeps?
 133                 git cat-file blob "$_name:.topdeps" >>"$_depsfile";
 134         fi;
 135
 136         _ret=0
 137         while read _dep; do
 138                 if ! ref_exists "$_dep" ; then
 139                         # All hope is lost
 140                         missing_deps="$missing_deps $_dep"
 141                         continue
 142                 fi
 143
 144                 _dep_is_tgish=1
 145                 ref_exists "refs/top-bases/$_dep"  ||
 146                         _dep_is_tgish=
 147
 148                 # Shoo shoo, keep our environment alone!
 149                 [ -z "$_dep_is_tgish" ] ||
 150                         (recurse_deps "$_cmd" "$_dep" "$@") ||
 151                         _ret=$?
 152
 153                 eval "$_cmd"
 154         done <"$_depsfile"
 155         missing_deps="${missing_deps# }"
 156         rm "$_depsfile"
 157         return $_ret
 158 }
 159
 160 # branch_needs_update
 161 # This is a helper function for determining whether given branch
 162 # is up-to-date wrt. its dependencies. It expects input as if it
 163 # is called as a recurse_deps() helper.
 164 # In case the branch does need update, it will echo it together
 165 # with the branch backtrace on the output (see needs_update()
 166 # description for details) and set $_ret to non-zero.
 167 branch_needs_update()
 168 {
 169         _dep_base_update=
 170         if [ -n "$_dep_is_tgish" ]; then
 171                 if has_remote "$_dep"; then
 172                         branch_contains "$_dep" "refs/remotes/$base_remote/$_dep" || _dep_base_update=%
 173                 fi
 174                 # This can possibly override the remote check result;
 175                 # we want to sync with our base first
 176                 branch_contains "$_dep" "refs/top-bases/$_dep" || _dep_base_update=:
 177         fi
 178
 179         if [ -n "$_dep_base_update" ]; then
 180                 # _dep needs to be synced with its base/remote
 181                 echo "$_dep_base_update $_dep $_depchain"
 182                 _ret=1
 183         elif [ -n "$_name" ] && ! branch_contains "refs/top-bases/$_name" "$_dep"; then
 184                 # Some new commits in _dep
 185                 echo "$_dep $_depchain"
 186                 _ret=1
 187         fi
 188 }
 189
 190 # needs_update NAME
 191 # This function is recursive; it outputs reverse path from NAME
 192 # to the branch (e.g. B_DIRTY B1 B2 NAME), one path per line,
 193 # inner paths first. Innermost name can be ':' if the head is
 194 # not in sync with the base or '%' if the head is not in sync
 195 # with the remote (in this order of priority).
 196 # It will also return non-zero status if NAME needs update.
 197 # If needs_update() hits missing dependencies, it will append
 198 # them to space-separated $missing_deps list and skip them.
 199 needs_update()
 200 {
 201         recurse_deps branch_needs_update "$@"
 202 }
 203
 204 # branch_empty NAME
 205 branch_empty()
 206 {
 207         [ -z "$(git diff-tree "refs/top-bases/$1" "$1" | fgrep -v "     .top")" ]
 208 }
 209
 210 # switch_to_base NAME [SEED]
 211 switch_to_base()
 212 {
 213         _base="refs/top-bases/$1"; _seed="$2"
 214         # We have to do all the hard work ourselves :/
 215         # This is like git checkout -b "$_base" "$_seed"
 216         # (or just git checkout "$_base"),
 217         # but does not create a detached HEAD.
 218         git read-tree -u -m HEAD "${_seed:-$_base}"
 219         [ -z "$_seed" ] || git update-ref "$_base" "$_seed"
 220         git symbolic-ref HEAD "$_base"
 221 }
 222
 223 # Show the help messages.
 224 do_help()
 225 {
 226         if [ -z "$1" ] ; then
 227                 # This is currently invoked in all kinds of circumstances,
 228                 # including when the user made a usage error. Should we end up
 229                 # providing more than a short help message, then we should
 230                 # differentiate.
 231                 # Petr's comment: http://marc.info/?l=git&m=122718711327376&w=2
 232
 233                 ## Build available commands list for help output
 234
 235                 cmds=
 236                 sep=
 237                 for cmd in "@cmddir@"/tg-*; do
 238                         ! [ -r "$cmd" ] && continue
 239                         # strip directory part and "tg-" prefix
 240                         cmd="$(basename "$cmd")"
 241                         cmd="${cmd#tg-}"
 242                         cmds="$cmds$sep$cmd"
 243                         sep="|"
 244                 done
 245
 246                 echo "TopGit v0.5 - A different patch queue manager"
 247                 echo "Usage: tg [-r REMOTE] ($cmds|help) ..."
 248         elif [ -r "@cmddir@"/tg-$1 ] ; then
 249                 @cmddir@/tg-$1 -h || :
 250                 echo
 251                 if [ -r "@sharedir@/tg-$1.txt" ] ; then
 252                         cat "@sharedir@/tg-$1.txt"
 253                 fi
 254         else
 255                 echo "`basename $0`: no help for $1" 1>&2
 256                 do_help
 257                 exit 1
 258         fi
 259 }
 260
 261
 262 ## Startup
 263
 264 [ -d "@cmddir@" ] ||
 265         die "No command directory: '@cmddir@'"
 266
 267 ## Initial setup
 268
 269 set -e
 270 git_dir="$(git rev-parse --git-dir)"
 271 root_dir="$(git rev-parse --show-cdup)"; root_dir="${root_dir:-.}"
 272 # Make sure root_dir doesn't end with a trailing slash.
 273 root_dir="${root_dir%/}"
 274 base_remote="$(git config topgit.remote 2>/dev/null)" || :
 275 tg="tg"
 276 # make sure merging the .top* files will always behave sanely
 277 setup_ours
 278 setup_hook "pre-commit"
 279
 280 ## Dispatch
 281
 282 # We were sourced from another script for our utility functions;
 283 # this is set by hooks.
 284 [ -z "$tg__include" ] || return 0
 285
 286 if [ "$1" = "-r" ]; then
 287         shift
 288         if [ -z "$1" ]; then
 289                 echo "Option -r requires an argument." >&2
 290                 do_help
 291                 exit 1
 292         fi
 293         base_remote="$1"; shift
 294         tg="$tg -r $base_remote"
 295 fi
 296
 297 cmd="$1"
 298 [ -n "$cmd" ] || { do_help; exit 1; }
 299 shift
 300
 301 case "$cmd" in
 302 help|--help|-h)
 303         do_help "$1"
 304         exit 0;;
 305 --hooks-path)
 306         # Internal command
 307         echo "@hooksdir@";;
 308 *)
 309         [ -r "@cmddir@"/tg-$cmd ] || {
 310                 echo "Unknown subcommand: $cmd" >&2
 311                 do_help
 312                 exit 1
 313         }
 314         . "@cmddir@"/tg-$cmd;;
 315 esac
 316
 317 # vim:noet