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/gitattributes" ] || ! grep -q topmsg "$git_dir/info/gitattributes"; then
  49                 {
  50                         echo -e ".topmsg\tmerge=ours"
  51                         echo -e ".topdeps\tmerge=ours"
  52                 } >>"$git_dir/info/gitattributes"
  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         _name="$1"; _base="$2"
  64         [ -n "$_base" ] || _base="refs/top-bases/$_name"
  65         # The caller should've verified $name is valid
  66         _commits="$(git rev-list "$_name" ^"$_base" | wc -l)"
  67         _nmcommits="$(git rev-list --no-merges "$_name" ^"$_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 # needs_update NAME [BRANCHPATH...]
  84 # This function is recursive; it outputs reverse path from NAME
  85 # to the branch (e.g. B_DIRTY B1 B2 NAME), one path per line,
  86 # inner paths first. Innermost name can be ':' if the head is
  87 # not in sync with the base.
  88 # It will also return non-zero status if NAME needs update.
  89 # If needs_update() hits missing dependencies, it will append
  90 # them to space-separated $missing_deps list and skip them.
  91 needs_update()
  92 {
  93         git cat-file blob "$1:.topdeps" 2>/dev/null | {
  94                 _ret=0
  95                 while read _dep; do
  96                         if !git rev-parse --verify "$_dep" >/dev/null 2>&1; then
  97                                 # All hope is lost
  98                                 missing_deps="$missing_deps $_dep"
  99                                 continue
 100                         fi
 101
 102                         _dep_is_tgish=1
 103                         git rev-parse --verify "refs/top-bases/$_dep" >/dev/null 2>&1 ||
 104                                 _dep_is_tgish=
 105
 106                         # Shoo shoo, keep our environment alone!
 107                         [ -z "$_dep_is_tgish" ] ||
 108                                 (needs_update "$_dep" "$@") ||
 109                                 _ret=$?
 110
 111                         _dep_base_uptodate=1
 112                         if [ -n "$_dep_is_tgish" ]; then
 113                                 branch_contains "$_dep" "refs/top-bases/$_dep" || _dep_base_uptodate=
 114                         fi
 115
 116                         if [ -z "$_dep_base_uptodate" ]; then
 117                                 # _dep needs to be synced with its base
 118                                 echo ": $_dep $*"
 119                                 _ret=1
 120                         elif ! branch_contains "refs/top-bases/$1" "$_dep"; then
 121                                 # Some new commits in _dep
 122                                 echo "$_dep $*"
 123                                 _ret=1
 124                         fi
 125                 done
 126                 exit $_ret
 127         }
 128 }
 129
 130 # branch_empty NAME
 131 branch_empty()
 132 {
 133         [ -z "$(git diff-tree "refs/top-bases/$1" "$1" | fgrep -v "     .top")" ]
 134 }
 135
 136 # switch_to_base NAME [SEED]
 137 switch_to_base()
 138 {
 139         _base="refs/top-bases/$1"; _seed="$2"
 140         # We have to do all the hard work ourselves :/
 141         # This is like git checkout -b "$_base" "$_seed"
 142         # (or just git checkout "$_base"),
 143         # but does not create a detached HEAD.
 144         git read-tree -u -m HEAD "${_seed:-$_base}"
 145         [ -z "$_seed" ] || git update-ref "$_base" "$_seed"
 146         git symbolic-ref HEAD "$_base"
 147 }
 148
 149
 150 ## Initial setup
 151
 152 set -e
 153 git_dir="$(git rev-parse --git-dir)"
 154 root_dir="$(git rev-parse --show-cdup)"; root_dir="${root_dir:-.}"
 155 # make sure merging the .top* files will always behave sanely
 156 setup_ours
 157 setup_hook "pre-commit"
 158
 159
 160 ## Dispatch
 161
 162 # We were sourced from another script for our utility functions;
 163 # this is set by hooks.
 164 [ -z "$tg__include" ] || return 0
 165
 166 cmd="$1"
 167 [ -n "$cmd" ] || die "He took a duck in the face at two hundred and fifty knots"
 168 shift
 169
 170 case "$cmd" in
 171 help)
 172         echo "TopGit v0.1 - A different patch queue manager"
 173         echo "Usage: tg (create|delete|info|patch|summary|update|help) ..."
 174         exit 1;;
 175 create|delete|info|patch|summary|update)
 176         . "@cmddir@"/tg-$cmd;;
 177 --hooks-path)
 178         # Internal command
 179         echo "@hooksdir@";;
 180 *)
 181         echo "Unknown subcommand: $cmd" >&2
 182         exit 1;;
 183 esac