chiark / gitweb /
e27ff3072d5da60dcc2e45dd7b806de6fa817625
[topgit.git] / 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 needs_update()
89 {
90         {
91         git cat-file blob "$1:.topdeps" 2>/dev/null |
92                 while read _dep; do
93                         _dep_is_tgish=1
94                         git rev-parse --verify "refs/top-bases/$_dep" >/dev/null 2>&1 ||
95                                 _dep_is_tgish=
96
97                         # Shoo shoo, keep our environment alone!
98                         [ -z "$_dep_is_tgish" ] || (needs_update "$_dep" "$@")
99
100                         _dep_base_uptodate=1
101                         if [ -n "$_dep_is_tgish" ]; then
102                                 branch_contains "$_dep" "refs/top-bases/$_dep" || _dep_base_uptodate=
103                         fi
104
105                         if [ -z "$_dep_base_uptodate" ]; then
106                                 # _dep needs to be synced with its base
107                                 echo ": $_dep $*"
108                         elif ! branch_contains "refs/top-bases/$1" "$_dep"; then
109                                 # Some new commits in _dep
110                                 echo "$_dep $*"
111                         fi
112                 done
113         } || : # $1 is not tracked by TopGit anymore
114 }
115
116 # branch_empty NAME
117 branch_empty()
118 {
119         [ -z "$(git diff-tree "refs/top-bases/$1" "$1" | fgrep -v "     .top")" ]
120 }
121
122 # switch_to_base NAME [SEED]
123 switch_to_base()
124 {
125         _base="refs/top-bases/$1"; _seed="$2"
126         # We have to do all the hard work ourselves :/
127         # This is like git checkout -b "$_base" "$_seed"
128         # (or just git checkout "$_base"),
129         # but does not create a detached HEAD.
130         git read-tree -u -m HEAD "${_seed:-$_base}"
131         [ -z "$_seed" ] || git update-ref "$_base" "$_seed"
132         git symbolic-ref HEAD "$_base"
133 }
134
135
136 ## Initial setup
137
138 set -e
139 git_dir="$(git rev-parse --git-dir)"
140 root_dir="$(git rev-parse --show-cdup)"; root_dir="${root_dir:-.}"
141 # make sure merging the .top* files will always behave sanely
142 setup_ours
143 setup_hook "pre-commit"
144
145
146 ## Dispatch
147
148 # We were sourced from another script for our utility functions;
149 # this is set by hooks.
150 [ -z "$tg__include" ] || return 0
151
152 cmd="$1"
153 [ -n "$cmd" ] || die "He took a duck in the face at two hundred and fifty knots"
154 shift
155
156 case "$cmd" in
157 help)
158         echo "TopGit v0.1 - A different patch queue manager"
159         echo "Usage: tg (create|delete|info|patch|summary|update|help) ..."
160         exit 1;;
161 create|delete|info|patch|summary|update)
162         . "@cmddir@"/tg-$cmd;;
163 --hooks-path)
164         # Internal command
165         echo "@hooksdir@";;
166 *)
167         echo "Unknown subcommand: $cmd" >&2
168         exit 1;;
169 esac