Documentation: fix dependency generation.
[git/gitweb.git] / git-merge.sh
blobb810fceaf8787f6c450abc628d0a329fe298b13f
1 #!/bin/sh
3 # Copyright (c) 2005 Junio C Hamano
6 . git-sh-setup || die "Not a git archive"
8 LF='
11 usage () {
12 die "git-merge [-n] [--no-commit] [-s <strategy>]... <merge-message> <head> <remote>+"
15 # all_strategies='resolve recursive stupid octopus'
17 all_strategies='recursive octopus resolve stupid ours'
18 default_strategies='resolve octopus'
19 use_strategies=
21 dropsave() {
22 rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
23 "$GIT_DIR/MERGE_SAVE" || exit 1
26 savestate() {
27 # Stash away any local modifications.
28 git-diff-index -z --name-only $head |
29 cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
32 restorestate() {
33 if test -f "$GIT_DIR/MERGE_SAVE"
34 then
35 git reset --hard $head
36 cpio -iuv <"$GIT_DIR/MERGE_SAVE"
37 git-update-index --refresh >/dev/null
41 finish () {
42 test '' = "$2" || echo "$2"
43 case "$merge_msg" in
44 '')
45 echo "No merge message -- not updating HEAD"
48 git-update-ref HEAD "$1" "$head" || exit 1
50 esac
52 case "$no_summary" in
53 '')
54 git-diff-tree -p -M "$head" "$1" |
55 git-apply --stat --summary
57 esac
60 while case "$#" in 0) break ;; esac
62 case "$1" in
63 -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
64 --no-summa|--no-summar|--no-summary)
65 no_summary=t ;;
66 --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
67 no_commit=t ;;
68 -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
69 --strateg=*|--strategy=*|\
70 -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
71 case "$#,$1" in
72 *,*=*)
73 strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
74 1,*)
75 usage ;;
77 strategy="$2"
78 shift ;;
79 esac
80 case " $all_strategies " in
81 *" $strategy "*)
82 use_strategies="$use_strategies$strategy " ;;
84 die "available strategies are: $all_strategies" ;;
85 esac
87 -*) usage ;;
88 *) break ;;
89 esac
90 shift
91 done
93 case "$use_strategies" in
94 '')
95 use_strategies=$default_strategies
97 esac
98 test "$#" -le 2 && usage ;# we need at least two heads.
100 merge_msg="$1"
101 shift
102 head_arg="$1"
103 head=$(git-rev-parse --verify "$1"^0) || usage
104 shift
106 # All the rest are remote heads
107 for remote
109 git-rev-parse --verify "$remote"^0 >/dev/null ||
110 die "$remote - not something we can merge"
111 done
113 common=$(git-show-branch --merge-base $head "$@")
114 echo "$head" >"$GIT_DIR/ORIG_HEAD"
116 case "$#,$common,$no_commit" in
117 *,'',*)
118 # No common ancestors found. We need a real merge.
120 1,"$1",*)
121 # If head can reach all the merge then we are up to date.
122 # but first the most common case of merging one remote
123 echo "Already up-to-date."
124 dropsave
125 exit 0
127 1,"$head",*)
128 # Again the most common case of merging one remote.
129 echo "Updating from $head to $1."
130 git-update-index --refresh 2>/dev/null
131 new_head=$(git-rev-parse --verify "$1^0") &&
132 git-read-tree -u -m $head "$new_head" &&
133 finish "$new_head" "Fast forward"
134 dropsave
135 exit 0
137 1,?*"$LF"?*,*)
138 # We are not doing octopus and not fast forward. Need a
139 # real merge.
141 1,*,)
142 # We are not doing octopus, not fast forward, and have only
143 # one common. See if it is really trivial.
144 echo "Trying really trivial in-index merge..."
145 git-update-index --refresh 2>/dev/null
146 if git-read-tree --trivial -m -u $common $head "$1" &&
147 result_tree=$(git-write-tree)
148 then
149 echo "Wonderful."
150 result_commit=$(
151 echo "$merge_msg" |
152 git-commit-tree $result_tree -p HEAD -p "$1"
153 ) || exit
154 finish "$result_commit" "In-index merge"
155 dropsave
156 exit 0
158 echo "Nope."
161 # An octopus. If we can reach all the remote we are up to date.
162 up_to_date=t
163 for remote
165 common_one=$(git-merge-base $head $remote)
166 if test "$common_one" != "$remote"
167 then
168 up_to_date=f
169 break
171 done
172 if test "$up_to_date" = t
173 then
174 echo "Already up-to-date. Yeeah!"
175 dropsave
176 exit 0
179 esac
181 # At this point, we need a real merge. No matter what strategy
182 # we use, it would operate on the index, possibly affecting the
183 # working tree, and when resolved cleanly, have the desired tree
184 # in the index -- this means that the index must be in sync with
185 # the $head commit. The strategies are responsible to ensure this.
187 case "$use_strategies" in
188 ?*' '?*)
189 # Stash away the local changes so that we can try more than one.
190 savestate
191 single_strategy=no
194 rm -f "$GIT_DIR/MERGE_SAVE"
195 single_strategy=yes
197 esac
199 result_tree= best_cnt=-1 best_strategy= wt_strategy=
200 for strategy in $use_strategies
202 test "$wt_strategy" = '' || {
203 echo "Rewinding the tree to pristine..."
204 restorestate
206 case "$single_strategy" in
208 echo "Trying merge strategy $strategy..."
210 esac
212 # Remember which strategy left the state in the working tree
213 wt_strategy=$strategy
215 git-merge-$strategy $common -- "$head_arg" "$@"
216 exit=$?
217 if test "$no_commit" = t && test "$exit" = 0
218 then
219 exit=1 ;# pretend it left conflicts.
222 test "$exit" = 0 || {
224 # The backend exits with 1 when conflicts are left to be resolved,
225 # with 2 when it does not handle the given merge at all.
227 if test "$exit" -eq 1
228 then
229 cnt=`{
230 git-diff-files --name-only
231 git-ls-files --unmerged
232 } | wc -l`
233 if test $best_cnt -le 0 -o $cnt -le $best_cnt
234 then
235 best_strategy=$strategy
236 best_cnt=$cnt
239 continue
242 # Automerge succeeded.
243 result_tree=$(git-write-tree) && break
244 done
246 # If we have a resulting tree, that means the strategy module
247 # auto resolved the merge cleanly.
248 if test '' != "$result_tree"
249 then
250 parents="-p $head"
251 for remote
253 parents="$parents -p $remote"
254 done
255 result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
256 finish "$result_commit" "Merge $result_commit, made by $wt_strategy."
257 dropsave
258 exit 0
261 # Pick the result from the best strategy and have the user fix it up.
262 case "$best_strategy" in
264 restorestate
265 die "No merge strategy handled the merge."
267 "$wt_strategy")
268 # We already have its result in the working tree.
271 echo "Rewinding the tree to pristine..."
272 restorestate
273 echo "Using the $best_strategy to prepare resolving by hand."
274 git-merge-$best_strategy $common -- "$head_arg" "$@"
276 esac
277 for remote
279 echo $remote
280 done >"$GIT_DIR/MERGE_HEAD"
281 echo $merge_msg >"$GIT_DIR/MERGE_MSG"
283 die "Automatic merge failed/prevented; fix up by hand"