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