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)\"/$1 \"\$@\""
  24         if fgrep -q "$hook_call" "$git_dir/hooks/$1"; then
  25                 # Another job well done!
  26                 return
  27         fi
  28         # Prepare incanation
  29         if [ -x "$git_dir/hooks/$1" ]; then
  30                 hook_call="$hook_call"' || exit $?'
  31         else
  32                 hook_call="exec $hook_call"
  33         fi
  34         # Insert call into the hook
  35         {
  36                 echo "#!/bin/sh"
  37                 echo "$hook_call"
  38                 cat "$git_dir/hooks/$1"
  39         } >"$git_dir/hooks/$1+"
  40         chmod a+x "$git_dir/hooks/$1+"
  41         mv "$git_dir/hooks/$1+" "$git_dir/hooks/$1"
  42 }
  43
  44 # setup_ours (no arguments)
  45 setup_ours()
  46 {
  47         if [ ! -s "$git_dir/info/gitattributes" ] || ! grep -q topmsg "$git_dir/info/gitattributes"; then
  48                 {
  49                         echo -e ".topmsg\tmerge=ours"
  50                         echo -e ".topdeps\tmerge=ours"
  51                 } >>"$git_dir/info/gitattributes"
  52         fi
  53         if ! git config merge.ours.driver >/dev/null; then
  54                 git config merge.ours.name '"always keep ours" merge driver'
  55                 git config merge.ours.driver 'touch %A'
  56         fi
  57 }
  58
  59 # measure_branch NAME [BASE]
  60 measure_branch()
  61 {
  62         _name="$1"; _base="$2"
  63         [ -n "$_base" ] || _base="refs/top-bases/$_name"
  64         # The caller should've verified $name is valid
  65         _commits="$(git rev-list "$_name" ^"$_base" | wc -l)"
  66         _nmcommits="$(git rev-list --no-merges "$_name" ^"$_base" | wc -l)"
  67         if [ $_commits -gt 1 ]; then
  68                 _suffix="commits"
  69         else
  70                 _suffix="commit"
  71         fi
  72         echo "$_commits/$_nmcommits $_suffix"
  73 }
  74
  75 # branch_contains B1 B2
  76 # Whether B1 is a superset of B2.
  77 branch_contains()
  78 {
  79         [ "$(git rev-list ^"$1" "$2" | wc -l)" -eq 0 ]
  80 }
  81
  82 # needs_update NAME [BRANCHPATH...]
  83 # This function is recursive; it outputs reverse path from NAME
  84 # to the branch (e.g. B_DIRTY B1 B2 NAME), one path per line,
  85 # inner paths first. Innermost name can be ':' if the head is
  86 # not in sync with the base.
  87 needs_update()
  88 {
  89         {
  90         git cat-file blob "$1:.topdeps" 2>/dev/null |
  91                 while read _dep; do
  92                         _dep_is_tgish=1
  93                         git rev-parse --verify "refs/top-bases/$_dep" >/dev/null 2>&1 ||
  94                                 _dep_is_tgish=
  95
  96                         # Shoo shoo, keep our environment alone!
  97                         [ -z "$_dep_is_tgish" ] || (needs_update "$_dep" "$@")
  98
  99                         _dep_base_uptodate=1
 100                         if [ -n "$_dep_is_tgish" ]; then
 101                                 branch_contains "$_dep" "refs/top-bases/$_dep" || _dep_base_uptodate=
 102                         fi
 103
 104                         if [ -z "$_dep_base_uptodate" ]; then
 105                                 # _dep needs to be synced with its base
 106                                 echo ": $_dep $*"
 107                         elif ! branch_contains "refs/top-bases/$1" "$_dep"; then
 108                                 # Some new commits in _dep
 109                                 echo "$_dep $*"
 110                         fi
 111                 done
 112         } || : # $1 is not tracked by TopGit anymore
 113 }
 114
 115 # switch_to_base NAME [SEED]
 116 switch_to_base()
 117 {
 118         _base="refs/top-bases/$1"; _seed="$2"
 119         # We have to do all the hard work ourselves :/
 120         # This is like git checkout -b "$_base" "$_seed"
 121         # (or just git checkout "$_base"),
 122         # but does not create a detached HEAD.
 123         git read-tree -u -m HEAD "${_seed:-$_base}"
 124         [ -z "$_seed" ] || git update-ref "$_base" "$_seed"
 125         git symbolic-ref HEAD "$_base"
 126 }
 127
 128
 129 ## Initial setup
 130
 131 set -e
 132 git_dir="$(git rev-parse --git-dir)"
 133 root_dir="$(git rev-parse --show-cdup)"; root_dir="${root_dir:-.}"
 134 # make sure merging the .top* files will always behave sanely
 135 setup_ours
 136 setup_hook "pre-commit"
 137
 138
 139 ## Dispatch
 140
 141 # We were sourced from another script for our utility functions;
 142 # this is set by hooks.
 143 [ -z "$tg__include" ] || return 0
 144
 145 cmd="$1"
 146 [ -n "$cmd" ] || die "He took a duck in the face at two hundred and fifty knots"
 147 shift
 148
 149 case "$cmd" in
 150 help)
 151         echo "TopGit - A different patch queue manager"
 152         echo "Usage: tg (create|delete|info|patch|summary|update|help) ..."
 153         exit 1;;
 154 create|delete|info|patch|summary|update)
 155         . "@cmddir@"/tg-$cmd;;
 156 --hooks-path)
 157         # Internal command
 158         echo "@hooksdir@";;
 159 *)
 160         echo "Unknown subcommand: $cmd" >&2
 161         exit 1;;
 162 esac