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/$1"; then
  26                 # Another job well done!
  27                 return
  28         fi
  29         # Prepare incanation
  30         if [ -x "$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 ^"$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 # recurse_deps CMD NAME [BRANCHPATH...]
  98 # Recursively eval CMD on all dependencies of NAME.
  99 # CMD can refer to $_name for queried branch name,
 100 # $_dep for dependency name,
 101 # $_depchain for space-seperated branch backtrace,
 102 # and the $_dep_is_tgish boolean.
 103 # It can modify $_ret to affect the return value
 104 # of the whole function.
 105 # If recurse_deps() hits missing dependencies, it will append
 106 # them to space-separated $missing_deps list and skip them.
 107 recurse_deps()
 108 {
 109         _cmd="$1"; shift
 110         _name="$1"; # no shift
 111         _depchain="$*"
 112
 113         _depsfile="$(mktemp -t tg-depsfile.XXXXXX)"
 114         # Check also our base against remote base. Checking our head
 115         # against remote head has to be done in the helper.
 116         if has_remote "top-bases/$_name"; then
 117                 echo "refs/remotes/$base_remote/top-bases/$_name" >>"$_depsfile"
 118         fi
 119         git cat-file blob "$_name:.topdeps" >>"$_depsfile"
 120
 121         _ret=0
 122         while read _dep; do
 123                 if ! ref_exists "$_dep" ; then
 124                         # All hope is lost
 125                         missing_deps="$missing_deps $_dep"
 126                         continue
 127                 fi
 128
 129                 _dep_is_tgish=1
 130                 ref_exists "refs/top-bases/$_dep"  ||
 131                         _dep_is_tgish=
 132
 133                 # Shoo shoo, keep our environment alone!
 134                 [ -z "$_dep_is_tgish" ] ||
 135                         (recurse_deps "$_cmd" "$_dep" "$@") ||
 136                         _ret=$?
 137
 138                 eval "$_cmd"
 139         done <"$_depsfile"
 140         missing_deps="${missing_deps# }"
 141         rm "$_depsfile"
 142         return $_ret
 143 }
 144
 145 # branch_needs_update
 146 # This is a helper function for determining whether given branch
 147 # is up-to-date wrt. its dependencies. It expects input as if it
 148 # is called as a recurse_deps() helper.
 149 # In case the branch does need update, it will echo it together
 150 # with the branch backtrace on the output (see needs_update()
 151 # description for details) and set $_ret to non-zero.
 152 branch_needs_update()
 153 {
 154         _dep_base_update=
 155         if [ -n "$_dep_is_tgish" ]; then
 156                 if has_remote "$_dep"; then
 157                         branch_contains "$_dep" "refs/remotes/$base_remote/$_dep" || _dep_base_update=%
 158                 fi
 159                 # This can possibly override the remote check result;
 160                 # we want to sync with our base first
 161                 branch_contains "$_dep" "refs/top-bases/$_dep" || _dep_base_update=:
 162         fi
 163
 164         if [ -n "$_dep_base_update" ]; then
 165                 # _dep needs to be synced with its base/remote
 166                 echo "$_dep_base_update $_dep $_depchain"
 167                 _ret=1
 168         elif [ -n "$_name" ] && ! branch_contains "refs/top-bases/$_name" "$_dep"; then
 169                 # Some new commits in _dep
 170                 echo "$_dep $_depchain"
 171                 _ret=1
 172         fi
 173 }
 174
 175 # needs_update NAME
 176 # This function is recursive; it outputs reverse path from NAME
 177 # to the branch (e.g. B_DIRTY B1 B2 NAME), one path per line,
 178 # inner paths first. Innermost name can be ':' if the head is
 179 # not in sync with the base or '%' if the head is not in sync
 180 # with the remote (in this order of priority).
 181 # It will also return non-zero status if NAME needs update.
 182 # If needs_update() hits missing dependencies, it will append
 183 # them to space-separated $missing_deps list and skip them.
 184 needs_update()
 185 {
 186         recurse_deps branch_needs_update "$@"
 187 }
 188
 189 # branch_empty NAME
 190 branch_empty()
 191 {
 192         [ -z "$(git diff-tree "refs/top-bases/$1" "$1" | fgrep -v "     .top")" ]
 193 }
 194
 195 # switch_to_base NAME [SEED]
 196 switch_to_base()
 197 {
 198         _base="refs/top-bases/$1"; _seed="$2"
 199         # We have to do all the hard work ourselves :/
 200         # This is like git checkout -b "$_base" "$_seed"
 201         # (or just git checkout "$_base"),
 202         # but does not create a detached HEAD.
 203         git read-tree -u -m HEAD "${_seed:-$_base}"
 204         [ -z "$_seed" ] || git update-ref "$_base" "$_seed"
 205         git symbolic-ref HEAD "$_base"
 206 }
 207
 208 # Show the help messages.
 209 do_help()
 210 {
 211         if [ -z "$1" ] ; then
 212                 ## Build available commands list for help output
 213
 214                 cmds=
 215                 sep=
 216                 for cmd in "@cmddir@"/tg-*; do
 217                         ! [ -r "$cmd" ] && continue
 218                         # strip directory part and "tg-" prefix
 219                         cmd="$(basename "$cmd")"
 220                         cmd="${cmd#tg-}"
 221                         cmds="$cmds$sep$cmd"
 222                         sep="|"
 223                 done
 224
 225                 echo "TopGit v0.2 - A different patch queue manager"
 226                 echo "Usage: tg ($cmds|help) ..."
 227         elif [ -r "@sharedir@/tg-$1.txt" ] ; then
 228                 cat "@sharedir@/tg-$1.txt"
 229         else
 230                 echo "`basename $0`: no help for $1" 1>&2
 231         fi
 232 }
 233
 234
 235 ## Initial setup
 236
 237 set -e
 238 git_dir="$(git rev-parse --git-dir)"
 239 root_dir="$(git rev-parse --show-cdup)"; root_dir="${root_dir:-.}"
 240 base_remote="$(git config topgit.remote 2>/dev/null)" || :
 241 # make sure merging the .top* files will always behave sanely
 242 setup_ours
 243 setup_hook "pre-commit"
 244
 245 [ -d "@cmddir@" ] ||
 246         die "No command directory: '@cmddir@'"
 247
 248 ## Dispatch
 249
 250 # We were sourced from another script for our utility functions;
 251 # this is set by hooks.
 252 [ -z "$tg__include" ] || return 0
 253
 254 cmd="$1"
 255 [ -n "$cmd" ] || die "He took a duck in the face at two hundred and fifty knots"
 256 shift
 257
 258 case "$cmd" in
 259 help|--help|-h)
 260         do_help "$1"
 261         exit 1;;
 262 --hooks-path)
 263         # Internal command
 264         echo "@hooksdir@";;
 265 *)
 266         [ -r "@cmddir@"/tg-$cmd ] || {
 267                 echo "Unknown subcommand: $cmd" >&2
 268                 exit 1
 269         }
 270         . "@cmddir@"/tg-$cmd;;
 271 esac