Merge branch 'pb/strbuf-read-file-doc' into maint
[git] / builtin / fmt-merge-msg.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "refs.h"
4 #include "commit.h"
5 #include "diff.h"
6 #include "revision.h"
7 #include "tag.h"
8 #include "string-list.h"
9 #include "branch.h"
10 #include "fmt-merge-msg.h"
11 #include "gpg-interface.h"
12
13 static const char * const fmt_merge_msg_usage[] = {
14         N_("git fmt-merge-msg [-m <message>] [--log[=<n>] | --no-log] [--file <file>]"),
15         NULL
16 };
17
18 static int use_branch_desc;
19
20 int fmt_merge_msg_config(const char *key, const char *value, void *cb)
21 {
22         if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
23                 int is_bool;
24                 merge_log_config = git_config_bool_or_int(key, value, &is_bool);
25                 if (!is_bool && merge_log_config < 0)
26                         return error("%s: negative length %s", key, value);
27                 if (is_bool && merge_log_config)
28                         merge_log_config = DEFAULT_MERGE_LOG_LEN;
29         } else if (!strcmp(key, "merge.branchdesc")) {
30                 use_branch_desc = git_config_bool(key, value);
31         } else {
32                 return git_default_config(key, value, cb);
33         }
34         return 0;
35 }
36
37 /* merge data per repository where the merged tips came from */
38 struct src_data {
39         struct string_list branch, tag, r_branch, generic;
40         int head_status;
41 };
42
43 struct origin_data {
44         unsigned char sha1[20];
45         unsigned is_local_branch:1;
46 };
47
48 static void init_src_data(struct src_data *data)
49 {
50         data->branch.strdup_strings = 1;
51         data->tag.strdup_strings = 1;
52         data->r_branch.strdup_strings = 1;
53         data->generic.strdup_strings = 1;
54 }
55
56 static struct string_list srcs = STRING_LIST_INIT_DUP;
57 static struct string_list origins = STRING_LIST_INIT_DUP;
58
59 struct merge_parents {
60         int alloc, nr;
61         struct merge_parent {
62                 unsigned char given[20];
63                 unsigned char commit[20];
64                 unsigned char used;
65         } *item;
66 };
67
68 /*
69  * I know, I know, this is inefficient, but you won't be pulling and merging
70  * hundreds of heads at a time anyway.
71  */
72 static struct merge_parent *find_merge_parent(struct merge_parents *table,
73                                               unsigned char *given,
74                                               unsigned char *commit)
75 {
76         int i;
77         for (i = 0; i < table->nr; i++) {
78                 if (given && hashcmp(table->item[i].given, given))
79                         continue;
80                 if (commit && hashcmp(table->item[i].commit, commit))
81                         continue;
82                 return &table->item[i];
83         }
84         return NULL;
85 }
86
87 static void add_merge_parent(struct merge_parents *table,
88                              unsigned char *given,
89                              unsigned char *commit)
90 {
91         if (table->nr && find_merge_parent(table, given, commit))
92                 return;
93         ALLOC_GROW(table->item, table->nr + 1, table->alloc);
94         hashcpy(table->item[table->nr].given, given);
95         hashcpy(table->item[table->nr].commit, commit);
96         table->item[table->nr].used = 0;
97         table->nr++;
98 }
99
100 static int handle_line(char *line, struct merge_parents *merge_parents)
101 {
102         int i, len = strlen(line);
103         struct origin_data *origin_data;
104         char *src;
105         const char *origin;
106         struct src_data *src_data;
107         struct string_list_item *item;
108         int pulling_head = 0;
109         unsigned char sha1[20];
110
111         if (len < 43 || line[40] != '\t')
112                 return 1;
113
114         if (starts_with(line + 41, "not-for-merge"))
115                 return 0;
116
117         if (line[41] != '\t')
118                 return 2;
119
120         i = get_sha1_hex(line, sha1);
121         if (i)
122                 return 3;
123
124         if (!find_merge_parent(merge_parents, sha1, NULL))
125                 return 0; /* subsumed by other parents */
126
127         origin_data = xcalloc(1, sizeof(struct origin_data));
128         hashcpy(origin_data->sha1, sha1);
129
130         if (line[len - 1] == '\n')
131                 line[len - 1] = 0;
132         line += 42;
133
134         /*
135          * At this point, line points at the beginning of comment e.g.
136          * "branch 'frotz' of git://that/repository.git".
137          * Find the repository name and point it with src.
138          */
139         src = strstr(line, " of ");
140         if (src) {
141                 *src = 0;
142                 src += 4;
143                 pulling_head = 0;
144         } else {
145                 src = line;
146                 pulling_head = 1;
147         }
148
149         item = unsorted_string_list_lookup(&srcs, src);
150         if (!item) {
151                 item = string_list_append(&srcs, src);
152                 item->util = xcalloc(1, sizeof(struct src_data));
153                 init_src_data(item->util);
154         }
155         src_data = item->util;
156
157         if (pulling_head) {
158                 origin = src;
159                 src_data->head_status |= 1;
160         } else if (starts_with(line, "branch ")) {
161                 origin_data->is_local_branch = 1;
162                 origin = line + 7;
163                 string_list_append(&src_data->branch, origin);
164                 src_data->head_status |= 2;
165         } else if (starts_with(line, "tag ")) {
166                 origin = line;
167                 string_list_append(&src_data->tag, origin + 4);
168                 src_data->head_status |= 2;
169         } else if (skip_prefix(line, "remote-tracking branch ", &origin)) {
170                 string_list_append(&src_data->r_branch, origin);
171                 src_data->head_status |= 2;
172         } else {
173                 origin = src;
174                 string_list_append(&src_data->generic, line);
175                 src_data->head_status |= 2;
176         }
177
178         if (!strcmp(".", src) || !strcmp(src, origin)) {
179                 int len = strlen(origin);
180                 if (origin[0] == '\'' && origin[len - 1] == '\'')
181                         origin = xmemdupz(origin + 1, len - 2);
182         } else
183                 origin = xstrfmt("%s of %s", origin, src);
184         if (strcmp(".", src))
185                 origin_data->is_local_branch = 0;
186         string_list_append(&origins, origin)->util = origin_data;
187         return 0;
188 }
189
190 static void print_joined(const char *singular, const char *plural,
191                 struct string_list *list, struct strbuf *out)
192 {
193         if (list->nr == 0)
194                 return;
195         if (list->nr == 1) {
196                 strbuf_addf(out, "%s%s", singular, list->items[0].string);
197         } else {
198                 int i;
199                 strbuf_addstr(out, plural);
200                 for (i = 0; i < list->nr - 1; i++)
201                         strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
202                                     list->items[i].string);
203                 strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
204         }
205 }
206
207 static void add_branch_desc(struct strbuf *out, const char *name)
208 {
209         struct strbuf desc = STRBUF_INIT;
210
211         if (!read_branch_desc(&desc, name)) {
212                 const char *bp = desc.buf;
213                 while (*bp) {
214                         const char *ep = strchrnul(bp, '\n');
215                         if (*ep)
216                                 ep++;
217                         strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
218                         bp = ep;
219                 }
220                 strbuf_complete_line(out);
221         }
222         strbuf_release(&desc);
223 }
224
225 #define util_as_integral(elem) ((intptr_t)((elem)->util))
226
227 static void record_person_from_buf(int which, struct string_list *people,
228                                    const char *buffer)
229 {
230         char *name_buf, *name, *name_end;
231         struct string_list_item *elem;
232         const char *field;
233
234         field = (which == 'a') ? "\nauthor " : "\ncommitter ";
235         name = strstr(buffer, field);
236         if (!name)
237                 return;
238         name += strlen(field);
239         name_end = strchrnul(name, '<');
240         if (*name_end)
241                 name_end--;
242         while (isspace(*name_end) && name <= name_end)
243                 name_end--;
244         if (name_end < name)
245                 return;
246         name_buf = xmemdupz(name, name_end - name + 1);
247
248         elem = string_list_lookup(people, name_buf);
249         if (!elem) {
250                 elem = string_list_insert(people, name_buf);
251                 elem->util = (void *)0;
252         }
253         elem->util = (void*)(util_as_integral(elem) + 1);
254         free(name_buf);
255 }
256
257
258 static void record_person(int which, struct string_list *people,
259                           struct commit *commit)
260 {
261         const char *buffer = get_commit_buffer(commit, NULL);
262         record_person_from_buf(which, people, buffer);
263         unuse_commit_buffer(commit, buffer);
264 }
265
266 static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
267 {
268         const struct string_list_item *a = a_, *b = b_;
269         return util_as_integral(b) - util_as_integral(a);
270 }
271
272 static void add_people_count(struct strbuf *out, struct string_list *people)
273 {
274         if (people->nr == 1)
275                 strbuf_addf(out, "%s", people->items[0].string);
276         else if (people->nr == 2)
277                 strbuf_addf(out, "%s (%d) and %s (%d)",
278                             people->items[0].string,
279                             (int)util_as_integral(&people->items[0]),
280                             people->items[1].string,
281                             (int)util_as_integral(&people->items[1]));
282         else if (people->nr)
283                 strbuf_addf(out, "%s (%d) and others",
284                             people->items[0].string,
285                             (int)util_as_integral(&people->items[0]));
286 }
287
288 static void credit_people(struct strbuf *out,
289                           struct string_list *them,
290                           int kind)
291 {
292         const char *label;
293         const char *me;
294
295         if (kind == 'a') {
296                 label = "By";
297                 me = git_author_info(IDENT_NO_DATE);
298         } else {
299                 label = "Via";
300                 me = git_committer_info(IDENT_NO_DATE);
301         }
302
303         if (!them->nr ||
304             (them->nr == 1 &&
305              me &&
306              skip_prefix(me, them->items->string, &me) &&
307              starts_with(me, " <")))
308                 return;
309         strbuf_addf(out, "\n%c %s ", comment_line_char, label);
310         add_people_count(out, them);
311 }
312
313 static void add_people_info(struct strbuf *out,
314                             struct string_list *authors,
315                             struct string_list *committers)
316 {
317         if (authors->nr)
318                 qsort(authors->items,
319                       authors->nr, sizeof(authors->items[0]),
320                       cmp_string_list_util_as_integral);
321         if (committers->nr)
322                 qsort(committers->items,
323                       committers->nr, sizeof(committers->items[0]),
324                       cmp_string_list_util_as_integral);
325
326         credit_people(out, authors, 'a');
327         credit_people(out, committers, 'c');
328 }
329
330 static void shortlog(const char *name,
331                      struct origin_data *origin_data,
332                      struct commit *head,
333                      struct rev_info *rev,
334                      struct fmt_merge_msg_opts *opts,
335                      struct strbuf *out)
336 {
337         int i, count = 0;
338         struct commit *commit;
339         struct object *branch;
340         struct string_list subjects = STRING_LIST_INIT_DUP;
341         struct string_list authors = STRING_LIST_INIT_DUP;
342         struct string_list committers = STRING_LIST_INIT_DUP;
343         int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
344         struct strbuf sb = STRBUF_INIT;
345         const unsigned char *sha1 = origin_data->sha1;
346         int limit = opts->shortlog_len;
347
348         branch = deref_tag(parse_object(sha1), sha1_to_hex(sha1), 40);
349         if (!branch || branch->type != OBJ_COMMIT)
350                 return;
351
352         setup_revisions(0, NULL, rev, NULL);
353         add_pending_object(rev, branch, name);
354         add_pending_object(rev, &head->object, "^HEAD");
355         head->object.flags |= UNINTERESTING;
356         if (prepare_revision_walk(rev))
357                 die("revision walk setup failed");
358         while ((commit = get_revision(rev)) != NULL) {
359                 struct pretty_print_context ctx = {0};
360
361                 if (commit->parents && commit->parents->next) {
362                         /* do not list a merge but count committer */
363                         if (opts->credit_people)
364                                 record_person('c', &committers, commit);
365                         continue;
366                 }
367                 if (!count && opts->credit_people)
368                         /* the 'tip' committer */
369                         record_person('c', &committers, commit);
370                 if (opts->credit_people)
371                         record_person('a', &authors, commit);
372                 count++;
373                 if (subjects.nr > limit)
374                         continue;
375
376                 format_commit_message(commit, "%s", &sb, &ctx);
377                 strbuf_ltrim(&sb);
378
379                 if (!sb.len)
380                         string_list_append(&subjects,
381                                            oid_to_hex(&commit->object.oid));
382                 else
383                         string_list_append(&subjects, strbuf_detach(&sb, NULL));
384         }
385
386         if (opts->credit_people)
387                 add_people_info(out, &authors, &committers);
388         if (count > limit)
389                 strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
390         else
391                 strbuf_addf(out, "\n* %s:\n", name);
392
393         if (origin_data->is_local_branch && use_branch_desc)
394                 add_branch_desc(out, name);
395
396         for (i = 0; i < subjects.nr; i++)
397                 if (i >= limit)
398                         strbuf_addf(out, "  ...\n");
399                 else
400                         strbuf_addf(out, "  %s\n", subjects.items[i].string);
401
402         clear_commit_marks((struct commit *)branch, flags);
403         clear_commit_marks(head, flags);
404         free_commit_list(rev->commits);
405         rev->commits = NULL;
406         rev->pending.nr = 0;
407
408         string_list_clear(&authors, 0);
409         string_list_clear(&committers, 0);
410         string_list_clear(&subjects, 0);
411 }
412
413 static void fmt_merge_msg_title(struct strbuf *out,
414         const char *current_branch) {
415         int i = 0;
416         char *sep = "";
417
418         strbuf_addstr(out, "Merge ");
419         for (i = 0; i < srcs.nr; i++) {
420                 struct src_data *src_data = srcs.items[i].util;
421                 const char *subsep = "";
422
423                 strbuf_addstr(out, sep);
424                 sep = "; ";
425
426                 if (src_data->head_status == 1) {
427                         strbuf_addstr(out, srcs.items[i].string);
428                         continue;
429                 }
430                 if (src_data->head_status == 3) {
431                         subsep = ", ";
432                         strbuf_addstr(out, "HEAD");
433                 }
434                 if (src_data->branch.nr) {
435                         strbuf_addstr(out, subsep);
436                         subsep = ", ";
437                         print_joined("branch ", "branches ", &src_data->branch,
438                                         out);
439                 }
440                 if (src_data->r_branch.nr) {
441                         strbuf_addstr(out, subsep);
442                         subsep = ", ";
443                         print_joined("remote-tracking branch ", "remote-tracking branches ",
444                                         &src_data->r_branch, out);
445                 }
446                 if (src_data->tag.nr) {
447                         strbuf_addstr(out, subsep);
448                         subsep = ", ";
449                         print_joined("tag ", "tags ", &src_data->tag, out);
450                 }
451                 if (src_data->generic.nr) {
452                         strbuf_addstr(out, subsep);
453                         print_joined("commit ", "commits ", &src_data->generic,
454                                         out);
455                 }
456                 if (strcmp(".", srcs.items[i].string))
457                         strbuf_addf(out, " of %s", srcs.items[i].string);
458         }
459
460         if (!strcmp("master", current_branch))
461                 strbuf_addch(out, '\n');
462         else
463                 strbuf_addf(out, " into %s\n", current_branch);
464 }
465
466 static void fmt_tag_signature(struct strbuf *tagbuf,
467                               struct strbuf *sig,
468                               const char *buf,
469                               unsigned long len)
470 {
471         const char *tag_body = strstr(buf, "\n\n");
472         if (tag_body) {
473                 tag_body += 2;
474                 strbuf_add(tagbuf, tag_body, buf + len - tag_body);
475         }
476         strbuf_complete_line(tagbuf);
477         if (sig->len) {
478                 strbuf_addch(tagbuf, '\n');
479                 strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
480         }
481 }
482
483 static void fmt_merge_msg_sigs(struct strbuf *out)
484 {
485         int i, tag_number = 0, first_tag = 0;
486         struct strbuf tagbuf = STRBUF_INIT;
487
488         for (i = 0; i < origins.nr; i++) {
489                 unsigned char *sha1 = origins.items[i].util;
490                 enum object_type type;
491                 unsigned long size, len;
492                 char *buf = read_sha1_file(sha1, &type, &size);
493                 struct strbuf sig = STRBUF_INIT;
494
495                 if (!buf || type != OBJ_TAG)
496                         goto next;
497                 len = parse_signature(buf, size);
498
499                 if (size == len)
500                         ; /* merely annotated */
501                 else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig, NULL)) {
502                         if (!sig.len)
503                                 strbuf_addstr(&sig, "gpg verification failed.\n");
504                 }
505
506                 if (!tag_number++) {
507                         fmt_tag_signature(&tagbuf, &sig, buf, len);
508                         first_tag = i;
509                 } else {
510                         if (tag_number == 2) {
511                                 struct strbuf tagline = STRBUF_INIT;
512                                 strbuf_addch(&tagline, '\n');
513                                 strbuf_add_commented_lines(&tagline,
514                                                 origins.items[first_tag].string,
515                                                 strlen(origins.items[first_tag].string));
516                                 strbuf_insert(&tagbuf, 0, tagline.buf,
517                                               tagline.len);
518                                 strbuf_release(&tagline);
519                         }
520                         strbuf_addch(&tagbuf, '\n');
521                         strbuf_add_commented_lines(&tagbuf,
522                                         origins.items[i].string,
523                                         strlen(origins.items[i].string));
524                         fmt_tag_signature(&tagbuf, &sig, buf, len);
525                 }
526                 strbuf_release(&sig);
527         next:
528                 free(buf);
529         }
530         if (tagbuf.len) {
531                 strbuf_addch(out, '\n');
532                 strbuf_addbuf(out, &tagbuf);
533         }
534         strbuf_release(&tagbuf);
535 }
536
537 static void find_merge_parents(struct merge_parents *result,
538                                struct strbuf *in, unsigned char *head)
539 {
540         struct commit_list *parents;
541         struct commit *head_commit;
542         int pos = 0, i, j;
543
544         parents = NULL;
545         while (pos < in->len) {
546                 int len;
547                 char *p = in->buf + pos;
548                 char *newline = strchr(p, '\n');
549                 unsigned char sha1[20];
550                 struct commit *parent;
551                 struct object *obj;
552
553                 len = newline ? newline - p : strlen(p);
554                 pos += len + !!newline;
555
556                 if (len < 43 ||
557                     get_sha1_hex(p, sha1) ||
558                     p[40] != '\t' ||
559                     p[41] != '\t')
560                         continue; /* skip not-for-merge */
561                 /*
562                  * Do not use get_merge_parent() here; we do not have
563                  * "name" here and we do not want to contaminate its
564                  * util field yet.
565                  */
566                 obj = parse_object(sha1);
567                 parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
568                 if (!parent)
569                         continue;
570                 commit_list_insert(parent, &parents);
571                 add_merge_parent(result, obj->oid.hash, parent->object.oid.hash);
572         }
573         head_commit = lookup_commit(head);
574         if (head_commit)
575                 commit_list_insert(head_commit, &parents);
576         parents = reduce_heads(parents);
577
578         while (parents) {
579                 struct commit *cmit = pop_commit(&parents);
580                 for (i = 0; i < result->nr; i++)
581                         if (!hashcmp(result->item[i].commit, cmit->object.oid.hash))
582                                 result->item[i].used = 1;
583         }
584
585         for (i = j = 0; i < result->nr; i++) {
586                 if (result->item[i].used) {
587                         if (i != j)
588                                 result->item[j] = result->item[i];
589                         j++;
590                 }
591         }
592         result->nr = j;
593 }
594
595 int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
596                   struct fmt_merge_msg_opts *opts)
597 {
598         int i = 0, pos = 0;
599         unsigned char head_sha1[20];
600         const char *current_branch;
601         void *current_branch_to_free;
602         struct merge_parents merge_parents;
603
604         memset(&merge_parents, 0, sizeof(merge_parents));
605
606         /* get current branch */
607         current_branch = current_branch_to_free =
608                 resolve_refdup("HEAD", RESOLVE_REF_READING, head_sha1, NULL);
609         if (!current_branch)
610                 die("No current branch");
611         if (starts_with(current_branch, "refs/heads/"))
612                 current_branch += 11;
613
614         find_merge_parents(&merge_parents, in, head_sha1);
615
616         /* get a line */
617         while (pos < in->len) {
618                 int len;
619                 char *newline, *p = in->buf + pos;
620
621                 newline = strchr(p, '\n');
622                 len = newline ? newline - p : strlen(p);
623                 pos += len + !!newline;
624                 i++;
625                 p[len] = 0;
626                 if (handle_line(p, &merge_parents))
627                         die ("Error in line %d: %.*s", i, len, p);
628         }
629
630         if (opts->add_title && srcs.nr)
631                 fmt_merge_msg_title(out, current_branch);
632
633         if (origins.nr)
634                 fmt_merge_msg_sigs(out);
635
636         if (opts->shortlog_len) {
637                 struct commit *head;
638                 struct rev_info rev;
639
640                 head = lookup_commit_or_die(head_sha1, "HEAD");
641                 init_revisions(&rev, NULL);
642                 rev.commit_format = CMIT_FMT_ONELINE;
643                 rev.ignore_merges = 1;
644                 rev.limited = 1;
645
646                 strbuf_complete_line(out);
647
648                 for (i = 0; i < origins.nr; i++)
649                         shortlog(origins.items[i].string,
650                                  origins.items[i].util,
651                                  head, &rev, opts, out);
652         }
653
654         strbuf_complete_line(out);
655         free(current_branch_to_free);
656         free(merge_parents.item);
657         return 0;
658 }
659
660 int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
661 {
662         const char *inpath = NULL;
663         const char *message = NULL;
664         int shortlog_len = -1;
665         struct option options[] = {
666                 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
667                   N_("populate log with at most <n> entries from shortlog"),
668                   PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
669                 { OPTION_INTEGER, 0, "summary", &shortlog_len, N_("n"),
670                   N_("alias for --log (deprecated)"),
671                   PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, NULL,
672                   DEFAULT_MERGE_LOG_LEN },
673                 OPT_STRING('m', "message", &message, N_("text"),
674                         N_("use <text> as start of message")),
675                 OPT_FILENAME('F', "file", &inpath, N_("file to read from")),
676                 OPT_END()
677         };
678
679         FILE *in = stdin;
680         struct strbuf input = STRBUF_INIT, output = STRBUF_INIT;
681         int ret;
682         struct fmt_merge_msg_opts opts;
683
684         git_config(fmt_merge_msg_config, NULL);
685         argc = parse_options(argc, argv, prefix, options, fmt_merge_msg_usage,
686                              0);
687         if (argc > 0)
688                 usage_with_options(fmt_merge_msg_usage, options);
689         if (shortlog_len < 0)
690                 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
691
692         if (inpath && strcmp(inpath, "-")) {
693                 in = fopen(inpath, "r");
694                 if (!in)
695                         die_errno("cannot open '%s'", inpath);
696         }
697
698         if (strbuf_read(&input, fileno(in), 0) < 0)
699                 die_errno("could not read input file");
700
701         if (message)
702                 strbuf_addstr(&output, message);
703
704         memset(&opts, 0, sizeof(opts));
705         opts.add_title = !message;
706         opts.credit_people = 1;
707         opts.shortlog_len = shortlog_len;
708
709         ret = fmt_merge_msg(&input, &output, &opts);
710         if (ret)
711                 return ret;
712         write_in_full(STDOUT_FILENO, output.buf, output.len);
713         return 0;
714 }