glossary: expand and clarify some definitions, prune cross-references
[git] / git-mergetool.sh
1 #!/bin/sh
2 #
3 # This program resolves merge conflicts in git
4 #
5 # Copyright (c) 2006 Theodore Y. Ts'o
6 #
7 # This file is licensed under the GPL v2, or a later version
8 # at the discretion of Junio C Hammano.
9 #
10
11 USAGE='[--tool=tool] [file to merge] ...'
12 SUBDIRECTORY_OK=Yes
13 . git-sh-setup
14 require_work_tree
15
16 # Returns true if the mode reflects a symlink
17 is_symlink () {
18     test "$1" = 120000
19 }
20
21 local_present () {
22     test -n "$local_mode"
23 }
24
25 remote_present () {
26     test -n "$remote_mode"
27 }
28
29 base_present () {
30     test -n "$base_mode"
31 }
32
33 cleanup_temp_files () {
34     if test "$1" = --save-backup ; then
35         mv -- "$BACKUP" "$path.orig"
36         rm -f -- "$LOCAL" "$REMOTE" "$BASE"
37     else
38         rm -f -- "$LOCAL" "$REMOTE" "$BASE" "$BACKUP"
39     fi
40 }
41
42 describe_file () {
43     mode="$1"
44     branch="$2"
45     file="$3"
46
47     printf "  {%s}: " "$branch"
48     if test -z "$mode"; then
49         echo "deleted"
50     elif is_symlink "$mode" ; then
51         echo "a symbolic link -> '$(cat "$file")'"
52     else
53         if base_present; then
54             echo "modified"
55         else
56             echo "created"
57         fi
58     fi
59 }
60
61
62 resolve_symlink_merge () {
63     while true; do
64         printf "Use (l)ocal or (r)emote, or (a)bort? "
65         read ans
66         case "$ans" in
67             [lL]*)
68                 git-checkout-index -f --stage=2 -- "$path"
69                 git-add -- "$path"
70                 cleanup_temp_files --save-backup
71                 return
72                 ;;
73             [rR]*)
74                 git-checkout-index -f --stage=3 -- "$path"
75                 git-add -- "$path"
76                 cleanup_temp_files --save-backup
77                 return
78                 ;;
79             [aA]*)
80                 exit 1
81                 ;;
82             esac
83         done
84 }
85
86 resolve_deleted_merge () {
87     while true; do
88         if base_present; then
89             printf "Use (m)odified or (d)eleted file, or (a)bort? "
90         else
91             printf "Use (c)reated or (d)eleted file, or (a)bort? "
92         fi
93         read ans
94         case "$ans" in
95             [mMcC]*)
96                 git-add -- "$path"
97                 cleanup_temp_files --save-backup
98                 return
99                 ;;
100             [dD]*)
101                 git-rm -- "$path" > /dev/null
102                 cleanup_temp_files
103                 return
104                 ;;
105             [aA]*)
106                 exit 1
107                 ;;
108             esac
109         done
110 }
111
112 check_unchanged () {
113     if test "$path" -nt "$BACKUP" ; then
114         status=0;
115     else
116         while true; do
117             echo "$path seems unchanged."
118             printf "Was the merge successful? [y/n] "
119             read answer < /dev/tty
120             case "$answer" in
121                 y*|Y*) status=0; break ;;
122                 n*|N*) status=1; break ;;
123             esac
124         done
125     fi
126 }
127
128 save_backup () {
129     if test "$status" -eq 0; then
130         mv -- "$BACKUP" "$path.orig"
131     fi
132 }
133
134 remove_backup () {
135     if test "$status" -eq 0; then
136         rm "$BACKUP"
137     fi
138 }
139
140 merge_file () {
141     path="$1"
142
143     f=`git-ls-files -u -- "$path"`
144     if test -z "$f" ; then
145         if test ! -f "$path" ; then
146             echo "$path: file not found"
147         else
148             echo "$path: file does not need merging"
149         fi
150         exit 1
151     fi
152
153     BACKUP="$path.BACKUP.$$"
154     LOCAL="$path.LOCAL.$$"
155     REMOTE="$path.REMOTE.$$"
156     BASE="$path.BASE.$$"
157
158     mv -- "$path" "$BACKUP"
159     cp -- "$BACKUP" "$path"
160
161     base_mode=`git ls-files -u -- "$path" | awk '{if ($3==1) print $1;}'`
162     local_mode=`git ls-files -u -- "$path" | awk '{if ($3==2) print $1;}'`
163     remote_mode=`git ls-files -u -- "$path" | awk '{if ($3==3) print $1;}'`
164
165     base_present   && git cat-file blob ":1:$path" > "$BASE" 2>/dev/null
166     local_present  && git cat-file blob ":2:$path" > "$LOCAL" 2>/dev/null
167     remote_present && git cat-file blob ":3:$path" > "$REMOTE" 2>/dev/null
168
169     if test -z "$local_mode" -o -z "$remote_mode"; then
170         echo "Deleted merge conflict for '$path':"
171         describe_file "$local_mode" "local" "$LOCAL"
172         describe_file "$remote_mode" "remote" "$REMOTE"
173         resolve_deleted_merge
174         return
175     fi
176
177     if is_symlink "$local_mode" || is_symlink "$remote_mode"; then
178         echo "Symbolic link merge conflict for '$path':"
179         describe_file "$local_mode" "local" "$LOCAL"
180         describe_file "$remote_mode" "remote" "$REMOTE"
181         resolve_symlink_merge
182         return
183     fi
184
185     echo "Normal merge conflict for '$path':"
186     describe_file "$local_mode" "local" "$LOCAL"
187     describe_file "$remote_mode" "remote" "$REMOTE"
188     printf "Hit return to start merge resolution tool (%s): " "$merge_tool"
189     read ans
190
191     case "$merge_tool" in
192         kdiff3)
193             if base_present ; then
194                 (kdiff3 --auto --L1 "$path (Base)" -L2 "$path (Local)" --L3 "$path (Remote)" \
195                     -o "$path" -- "$BASE" "$LOCAL" "$REMOTE" > /dev/null 2>&1)
196             else
197                 (kdiff3 --auto -L1 "$path (Local)" --L2 "$path (Remote)" \
198                     -o "$path" -- "$LOCAL" "$REMOTE" > /dev/null 2>&1)
199             fi
200             status=$?
201             remove_backup
202             ;;
203         tkdiff)
204             if base_present ; then
205                 tkdiff -a "$BASE" -o "$path" -- "$LOCAL" "$REMOTE"
206             else
207                 tkdiff -o "$path" -- "$LOCAL" "$REMOTE"
208             fi
209             status=$?
210             save_backup
211             ;;
212         meld|vimdiff)
213             touch "$BACKUP"
214             $merge_tool -- "$LOCAL" "$path" "$REMOTE"
215             check_unchanged
216             save_backup
217             ;;
218         xxdiff)
219             touch "$BACKUP"
220             if base_present ; then
221                 xxdiff -X --show-merged-pane \
222                     -R 'Accel.SaveAsMerged: "Ctrl-S"' \
223                     -R 'Accel.Search: "Ctrl+F"' \
224                     -R 'Accel.SearchForward: "Ctrl-G"' \
225                     --merged-file "$path" -- "$LOCAL" "$BASE" "$REMOTE"
226             else
227                 xxdiff -X --show-merged-pane \
228                     -R 'Accel.SaveAsMerged: "Ctrl-S"' \
229                     -R 'Accel.Search: "Ctrl+F"' \
230                     -R 'Accel.SearchForward: "Ctrl-G"' \
231                     --merged-file "$path" -- "$LOCAL" "$REMOTE"
232             fi
233             check_unchanged
234             save_backup
235             ;;
236         opendiff)
237             touch "$BACKUP"
238             if base_present; then
239                 opendiff "$LOCAL" "$REMOTE" -ancestor "$BASE" -merge "$path" | cat
240             else
241                 opendiff "$LOCAL" "$REMOTE" -merge "$path" | cat
242             fi
243             check_unchanged
244             save_backup
245             ;;
246         emerge)
247             if base_present ; then
248                 emacs -f emerge-files-with-ancestor-command "$LOCAL" "$REMOTE" "$BASE" "$path"
249             else
250                 emacs -f emerge-files-command "$LOCAL" "$REMOTE" "$path"
251             fi
252             status=$?
253             save_backup
254             ;;
255     esac
256     if test "$status" -ne 0; then
257         echo "merge of $path failed" 1>&2
258         mv -- "$BACKUP" "$path"
259         exit 1
260     fi
261     git add -- "$path"
262     cleanup_temp_files
263 }
264
265 while case $# in 0) break ;; esac
266 do
267     case "$1" in
268         -t|--tool*)
269             case "$#,$1" in
270                 *,*=*)
271                     merge_tool=`expr "z$1" : 'z-[^=]*=\(.*\)'`
272                     ;;
273                 1,*)
274                     usage ;;
275                 *)
276                     merge_tool="$2"
277                     shift ;;
278             esac
279             ;;
280         --)
281             break
282             ;;
283         -*)
284             usage
285             ;;
286         *)
287             break
288             ;;
289     esac
290     shift
291 done
292
293 if test -z "$merge_tool"; then
294     merge_tool=`git-config merge.tool`
295     case "$merge_tool" in
296         kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | "")
297             ;; # happy
298         *)
299             echo >&2 "git config option merge.tool set to unknown tool: $merge_tool"
300             echo >&2 "Resetting to default..."
301             unset merge_tool
302             ;;
303     esac
304 fi
305
306 if test -z "$merge_tool" ; then
307     if type kdiff3 >/dev/null 2>&1 && test -n "$DISPLAY"; then
308         merge_tool="kdiff3";
309     elif type tkdiff >/dev/null 2>&1 && test -n "$DISPLAY"; then
310         merge_tool=tkdiff
311     elif type xxdiff >/dev/null 2>&1 && test -n "$DISPLAY"; then
312         merge_tool=xxdiff
313     elif type meld >/dev/null 2>&1 && test -n "$DISPLAY"; then
314         merge_tool=meld
315     elif type opendiff >/dev/null 2>&1; then
316         merge_tool=opendiff
317     elif type emacs >/dev/null 2>&1; then
318         merge_tool=emerge
319     elif type vimdiff >/dev/null 2>&1; then
320         merge_tool=vimdiff
321     else
322         echo "No available merge resolution programs available."
323         exit 1
324     fi
325 fi
326
327 case "$merge_tool" in
328     kdiff3|tkdiff|meld|xxdiff|vimdiff|opendiff)
329         if ! type "$merge_tool" > /dev/null 2>&1; then
330             echo "The merge tool $merge_tool is not available"
331             exit 1
332         fi
333         ;;
334     emerge)
335         if ! type "emacs" > /dev/null 2>&1; then
336             echo "Emacs is not available"
337             exit 1
338         fi
339         ;;
340     *)
341         echo "Unknown merge tool: $merge_tool"
342         exit 1
343         ;;
344 esac
345
346 if test $# -eq 0 ; then
347         files=`git ls-files -u | sed -e 's/^[^  ]*      //' | sort -u`
348         if test -z "$files" ; then
349                 echo "No files need merging"
350                 exit 0
351         fi
352         echo Merging the files: $files
353         git ls-files -u | sed -e 's/^[^ ]*      //' | sort -u | while read i
354         do
355                 printf "\n"
356                 merge_file "$i" < /dev/tty > /dev/tty
357         done
358 else
359         while test $# -gt 0; do
360                 printf "\n"
361                 merge_file "$1"
362                 shift
363         done
364 fi
365 exit 0