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