Code

Fix a warning (on cygwin) to allow -Werror
[git.git] / builtin-revert.c
1 #include "cache.h"
2 #include "builtin.h"
3 #include "object.h"
4 #include "commit.h"
5 #include "tag.h"
6 #include "wt-status.h"
7 #include "run-command.h"
8 #include "exec_cmd.h"
9 #include "utf8.h"
10 #include "parse-options.h"
11 #include "cache-tree.h"
12 #include "diff.h"
13 #include "revision.h"
15 /*
16  * This implements the builtins revert and cherry-pick.
17  *
18  * Copyright (c) 2007 Johannes E. Schindelin
19  *
20  * Based on git-revert.sh, which is
21  *
22  * Copyright (c) 2005 Linus Torvalds
23  * Copyright (c) 2005 Junio C Hamano
24  */
26 static const char * const revert_usage[] = {
27         "git revert [options] <commit-ish>",
28         NULL
29 };
31 static const char * const cherry_pick_usage[] = {
32         "git cherry-pick [options] <commit-ish>",
33         NULL
34 };
36 static int edit, no_replay, no_commit, mainline, signoff;
37 static enum { REVERT, CHERRY_PICK } action;
38 static struct commit *commit;
40 static const char *me;
42 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
44 static void parse_args(int argc, const char **argv)
45 {
46         const char * const * usage_str =
47                 action == REVERT ?  revert_usage : cherry_pick_usage;
48         unsigned char sha1[20];
49         const char *arg;
50         int noop;
51         struct option options[] = {
52                 OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
53                 OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
54                 OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
55                 OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
56                 OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
57                 OPT_INTEGER('m', "mainline", &mainline, "parent number"),
58                 OPT_END(),
59         };
61         if (parse_options(argc, argv, options, usage_str, 0) != 1)
62                 usage_with_options(usage_str, options);
63         arg = argv[0];
65         if (get_sha1(arg, sha1))
66                 die ("Cannot find '%s'", arg);
67         commit = (struct commit *)parse_object(sha1);
68         if (!commit)
69                 die ("Could not find %s", sha1_to_hex(sha1));
70         if (commit->object.type == OBJ_TAG) {
71                 commit = (struct commit *)
72                         deref_tag((struct object *)commit, arg, strlen(arg));
73         }
74         if (commit->object.type != OBJ_COMMIT)
75                 die ("'%s' does not point to a commit", arg);
76 }
78 static char *get_oneline(const char *message)
79 {
80         char *result;
81         const char *p = message, *abbrev, *eol;
82         int abbrev_len, oneline_len;
84         if (!p)
85                 die ("Could not read commit message of %s",
86                                 sha1_to_hex(commit->object.sha1));
87         while (*p && (*p != '\n' || p[1] != '\n'))
88                 p++;
90         if (*p) {
91                 p += 2;
92                 for (eol = p + 1; *eol && *eol != '\n'; eol++)
93                         ; /* do nothing */
94         } else
95                 eol = p;
96         abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
97         abbrev_len = strlen(abbrev);
98         oneline_len = eol - p;
99         result = xmalloc(abbrev_len + 5 + oneline_len);
100         memcpy(result, abbrev, abbrev_len);
101         memcpy(result + abbrev_len, "... ", 4);
102         memcpy(result + abbrev_len + 4, p, oneline_len);
103         result[abbrev_len + 4 + oneline_len] = '\0';
104         return result;
107 static char *get_encoding(const char *message)
109         const char *p = message, *eol;
111         if (!p)
112                 die ("Could not read commit message of %s",
113                                 sha1_to_hex(commit->object.sha1));
114         while (*p && *p != '\n') {
115                 for (eol = p + 1; *eol && *eol != '\n'; eol++)
116                         ; /* do nothing */
117                 if (!prefixcmp(p, "encoding ")) {
118                         char *result = xmalloc(eol - 8 - p);
119                         strlcpy(result, p + 9, eol - 8 - p);
120                         return result;
121                 }
122                 p = eol;
123                 if (*p == '\n')
124                         p++;
125         }
126         return NULL;
129 static struct lock_file msg_file;
130 static int msg_fd;
132 static void add_to_msg(const char *string)
134         int len = strlen(string);
135         if (write_in_full(msg_fd, string, len) < 0)
136                 die ("Could not write to MERGE_MSG");
139 static void add_message_to_msg(const char *message)
141         const char *p = message;
142         while (*p && (*p != '\n' || p[1] != '\n'))
143                 p++;
145         if (!*p)
146                 add_to_msg(sha1_to_hex(commit->object.sha1));
148         p += 2;
149         add_to_msg(p);
150         return;
153 static void set_author_ident_env(const char *message)
155         const char *p = message;
156         if (!p)
157                 die ("Could not read commit message of %s",
158                                 sha1_to_hex(commit->object.sha1));
159         while (*p && *p != '\n') {
160                 const char *eol;
162                 for (eol = p; *eol && *eol != '\n'; eol++)
163                         ; /* do nothing */
164                 if (!prefixcmp(p, "author ")) {
165                         char *line, *pend, *email, *timestamp;
167                         p += 7;
168                         line = xmemdupz(p, eol - p);
169                         email = strchr(line, '<');
170                         if (!email)
171                                 die ("Could not extract author email from %s",
172                                         sha1_to_hex(commit->object.sha1));
173                         if (email == line)
174                                 pend = line;
175                         else
176                                 for (pend = email; pend != line + 1 &&
177                                                 isspace(pend[-1]); pend--);
178                                         ; /* do nothing */
179                         *pend = '\0';
180                         email++;
181                         timestamp = strchr(email, '>');
182                         if (!timestamp)
183                                 die ("Could not extract author time from %s",
184                                         sha1_to_hex(commit->object.sha1));
185                         *timestamp = '\0';
186                         for (timestamp++; *timestamp && isspace(*timestamp);
187                                         timestamp++)
188                                 ; /* do nothing */
189                         setenv("GIT_AUTHOR_NAME", line, 1);
190                         setenv("GIT_AUTHOR_EMAIL", email, 1);
191                         setenv("GIT_AUTHOR_DATE", timestamp, 1);
192                         free(line);
193                         return;
194                 }
195                 p = eol;
196                 if (*p == '\n')
197                         p++;
198         }
199         die ("No author information found in %s",
200                         sha1_to_hex(commit->object.sha1));
203 static int merge_recursive(const char *base_sha1,
204                 const char *head_sha1, const char *head_name,
205                 const char *next_sha1, const char *next_name)
207         char buffer[256];
208         const char *argv[6];
209         int i = 0;
211         sprintf(buffer, "GITHEAD_%s", head_sha1);
212         setenv(buffer, head_name, 1);
213         sprintf(buffer, "GITHEAD_%s", next_sha1);
214         setenv(buffer, next_name, 1);
216         /*
217          * This three way merge is an interesting one.  We are at
218          * $head, and would want to apply the change between $commit
219          * and $prev on top of us (when reverting), or the change between
220          * $prev and $commit on top of us (when cherry-picking or replaying).
221          */
222         argv[i++] = "merge-recursive";
223         if (base_sha1)
224                 argv[i++] = base_sha1;
225         argv[i++] = "--";
226         argv[i++] = head_sha1;
227         argv[i++] = next_sha1;
228         argv[i++] = NULL;
230         return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN | RUN_GIT_CMD);
233 static char *help_msg(const unsigned char *sha1)
235         static char helpbuf[1024];
236         char *msg = getenv("GIT_CHERRY_PICK_HELP");
238         if (msg)
239                 return msg;
241         strcpy(helpbuf, "  After resolving the conflicts,\n"
242                "mark the corrected paths with 'git add <paths>' "
243                "or 'git rm <paths>' and commit the result.");
245         if (action == CHERRY_PICK) {
246                 sprintf(helpbuf + strlen(helpbuf),
247                         "\nWhen commiting, use the option "
248                         "'-c %s' to retain authorship and message.",
249                         find_unique_abbrev(sha1, DEFAULT_ABBREV));
250         }
251         return helpbuf;
254 static int index_is_dirty(void)
256         struct rev_info rev;
257         init_revisions(&rev, NULL);
258         setup_revisions(0, NULL, &rev, "HEAD");
259         DIFF_OPT_SET(&rev.diffopt, QUIET);
260         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
261         run_diff_index(&rev, 1);
262         return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
265 static int revert_or_cherry_pick(int argc, const char **argv)
267         unsigned char head[20];
268         struct commit *base, *next, *parent;
269         int i;
270         char *oneline, *reencoded_message = NULL;
271         const char *message, *encoding;
272         const char *defmsg = xstrdup(git_path("MERGE_MSG"));
274         git_config(git_default_config, NULL);
275         me = action == REVERT ? "revert" : "cherry-pick";
276         setenv(GIT_REFLOG_ACTION, me, 0);
277         parse_args(argc, argv);
279         /* this is copied from the shell script, but it's never triggered... */
280         if (action == REVERT && !no_replay)
281                 die("revert is incompatible with replay");
283         if (no_commit) {
284                 /*
285                  * We do not intend to commit immediately.  We just want to
286                  * merge the differences in, so let's compute the tree
287                  * that represents the "current" state for merge-recursive
288                  * to work on.
289                  */
290                 if (write_cache_as_tree(head, 0, NULL))
291                         die ("Your index file is unmerged.");
292         } else {
293                 if (get_sha1("HEAD", head))
294                         die ("You do not have a valid HEAD");
295                 if (read_cache() < 0)
296                         die("could not read the index");
297                 if (index_is_dirty())
298                         die ("Dirty index: cannot %s", me);
299                 discard_cache();
300         }
302         if (!commit->parents) {
303                 if (action == REVERT)
304                         die ("Cannot revert a root commit");
305                 parent = NULL;
306         }
307         else if (commit->parents->next) {
308                 /* Reverting or cherry-picking a merge commit */
309                 int cnt;
310                 struct commit_list *p;
312                 if (!mainline)
313                         die("Commit %s is a merge but no -m option was given.",
314                             sha1_to_hex(commit->object.sha1));
316                 for (cnt = 1, p = commit->parents;
317                      cnt != mainline && p;
318                      cnt++)
319                         p = p->next;
320                 if (cnt != mainline || !p)
321                         die("Commit %s does not have parent %d",
322                             sha1_to_hex(commit->object.sha1), mainline);
323                 parent = p->item;
324         } else if (0 < mainline)
325                 die("Mainline was specified but commit %s is not a merge.",
326                     sha1_to_hex(commit->object.sha1));
327         else
328                 parent = commit->parents->item;
330         if (!(message = commit->buffer))
331                 die ("Cannot get commit message for %s",
332                                 sha1_to_hex(commit->object.sha1));
334         /*
335          * "commit" is an existing commit.  We would want to apply
336          * the difference it introduces since its first parent "prev"
337          * on top of the current HEAD if we are cherry-pick.  Or the
338          * reverse of it if we are revert.
339          */
341         msg_fd = hold_lock_file_for_update(&msg_file, defmsg, 1);
343         encoding = get_encoding(message);
344         if (!encoding)
345                 encoding = "utf-8";
346         if (!git_commit_encoding)
347                 git_commit_encoding = "utf-8";
348         if ((reencoded_message = reencode_string(message,
349                                         git_commit_encoding, encoding)))
350                 message = reencoded_message;
352         oneline = get_oneline(message);
354         if (action == REVERT) {
355                 char *oneline_body = strchr(oneline, ' ');
357                 base = commit;
358                 next = parent;
359                 add_to_msg("Revert \"");
360                 add_to_msg(oneline_body + 1);
361                 add_to_msg("\"\n\nThis reverts commit ");
362                 add_to_msg(sha1_to_hex(commit->object.sha1));
363                 add_to_msg(".\n");
364         } else {
365                 base = parent;
366                 next = commit;
367                 set_author_ident_env(message);
368                 add_message_to_msg(message);
369                 if (no_replay) {
370                         add_to_msg("(cherry picked from commit ");
371                         add_to_msg(sha1_to_hex(commit->object.sha1));
372                         add_to_msg(")\n");
373                 }
374         }
376         if (merge_recursive(base == NULL ?
377                                 NULL : sha1_to_hex(base->object.sha1),
378                                 sha1_to_hex(head), "HEAD",
379                                 sha1_to_hex(next->object.sha1), oneline) ||
380                         write_cache_as_tree(head, 0, NULL)) {
381                 add_to_msg("\nConflicts:\n\n");
382                 read_cache();
383                 for (i = 0; i < active_nr;) {
384                         struct cache_entry *ce = active_cache[i++];
385                         if (ce_stage(ce)) {
386                                 add_to_msg("\t");
387                                 add_to_msg(ce->name);
388                                 add_to_msg("\n");
389                                 while (i < active_nr && !strcmp(ce->name,
390                                                 active_cache[i]->name))
391                                         i++;
392                         }
393                 }
394                 if (commit_lock_file(&msg_file) < 0)
395                         die ("Error wrapping up %s", defmsg);
396                 fprintf(stderr, "Automatic %s failed.%s\n",
397                         me, help_msg(commit->object.sha1));
398                 exit(1);
399         }
400         if (commit_lock_file(&msg_file) < 0)
401                 die ("Error wrapping up %s", defmsg);
402         fprintf(stderr, "Finished one %s.\n", me);
404         /*
405          *
406          * If we are cherry-pick, and if the merge did not result in
407          * hand-editing, we will hit this commit and inherit the original
408          * author date and name.
409          * If we are revert, or if our cherry-pick results in a hand merge,
410          * we had better say that the current user is responsible for that.
411          */
413         if (!no_commit) {
414                 /* 6 is max possible length of our args array including NULL */
415                 const char *args[6];
416                 int i = 0;
417                 args[i++] = "commit";
418                 args[i++] = "-n";
419                 if (signoff)
420                         args[i++] = "-s";
421                 if (!edit) {
422                         args[i++] = "-F";
423                         args[i++] = defmsg;
424                 }
425                 args[i] = NULL;
426                 return execv_git_cmd(args);
427         }
428         free(reencoded_message);
430         return 0;
433 int cmd_revert(int argc, const char **argv, const char *prefix)
435         if (isatty(0))
436                 edit = 1;
437         no_replay = 1;
438         action = REVERT;
439         return revert_or_cherry_pick(argc, argv);
442 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
444         no_replay = 0;
445         action = CHERRY_PICK;
446         return revert_or_cherry_pick(argc, argv);