Merge branch 'mh/maint-http-proxy-fix'
[git] / builtin-rev-list.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "tag.h"
4 #include "commit.h"
5 #include "tree.h"
6 #include "blob.h"
7 #include "tree-walk.h"
8 #include "diff.h"
9 #include "revision.h"
10 #include "list-objects.h"
11 #include "builtin.h"
12 #include "log-tree.h"
13
14 /* bits #0-15 in revision.h */
15
16 #define COUNTED         (1u<<16)
17
18 static const char rev_list_usage[] =
19 "git-rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
20 "  limiting output:\n"
21 "    --max-count=nr\n"
22 "    --max-age=epoch\n"
23 "    --min-age=epoch\n"
24 "    --sparse\n"
25 "    --no-merges\n"
26 "    --remove-empty\n"
27 "    --all\n"
28 "    --branches\n"
29 "    --tags\n"
30 "    --remotes\n"
31 "    --stdin\n"
32 "    --quiet\n"
33 "  ordering output:\n"
34 "    --topo-order\n"
35 "    --date-order\n"
36 "  formatting output:\n"
37 "    --parents\n"
38 "    --objects | --objects-edge\n"
39 "    --unpacked\n"
40 "    --header | --pretty\n"
41 "    --abbrev=nr | --no-abbrev\n"
42 "    --abbrev-commit\n"
43 "    --left-right\n"
44 "  special purpose:\n"
45 "    --bisect\n"
46 "    --bisect-vars\n"
47 "    --bisect-all"
48 ;
49
50 static struct rev_info revs;
51
52 static int bisect_list;
53 static int show_timestamp;
54 static int hdr_termination;
55 static const char *header_prefix;
56
57 static void finish_commit(struct commit *commit);
58 static void show_commit(struct commit *commit)
59 {
60         if (show_timestamp)
61                 printf("%lu ", commit->date);
62         if (header_prefix)
63                 fputs(header_prefix, stdout);
64         if (commit->object.flags & BOUNDARY)
65                 putchar('-');
66         else if (commit->object.flags & UNINTERESTING)
67                 putchar('^');
68         else if (revs.left_right) {
69                 if (commit->object.flags & SYMMETRIC_LEFT)
70                         putchar('<');
71                 else
72                         putchar('>');
73         }
74         if (revs.abbrev_commit && revs.abbrev)
75                 fputs(find_unique_abbrev(commit->object.sha1, revs.abbrev),
76                       stdout);
77         else
78                 fputs(sha1_to_hex(commit->object.sha1), stdout);
79         if (revs.parents) {
80                 struct commit_list *parents = commit->parents;
81                 while (parents) {
82                         printf(" %s", sha1_to_hex(parents->item->object.sha1));
83                         parents = parents->next;
84                 }
85         }
86         show_decorations(commit);
87         if (revs.commit_format == CMIT_FMT_ONELINE)
88                 putchar(' ');
89         else
90                 putchar('\n');
91
92         if (revs.verbose_header && commit->buffer) {
93                 struct strbuf buf;
94                 strbuf_init(&buf, 0);
95                 pretty_print_commit(revs.commit_format, commit,
96                                     &buf, revs.abbrev, NULL, NULL,
97                                     revs.date_mode, 0);
98                 if (buf.len)
99                         printf("%s%c", buf.buf, hdr_termination);
100                 strbuf_release(&buf);
101         }
102         maybe_flush_or_die(stdout, "stdout");
103         finish_commit(commit);
104 }
105
106 static void finish_commit(struct commit *commit)
107 {
108         if (commit->parents) {
109                 free_commit_list(commit->parents);
110                 commit->parents = NULL;
111         }
112         free(commit->buffer);
113         commit->buffer = NULL;
114 }
115
116 static void finish_object(struct object_array_entry *p)
117 {
118         if (p->item->type == OBJ_BLOB && !has_sha1_file(p->item->sha1))
119                 die("missing blob object '%s'", sha1_to_hex(p->item->sha1));
120 }
121
122 static void show_object(struct object_array_entry *p)
123 {
124         /* An object with name "foo\n0000000..." can be used to
125          * confuse downstream git-pack-objects very badly.
126          */
127         const char *ep = strchr(p->name, '\n');
128
129         finish_object(p);
130         if (ep) {
131                 printf("%s %.*s\n", sha1_to_hex(p->item->sha1),
132                        (int) (ep - p->name),
133                        p->name);
134         }
135         else
136                 printf("%s %s\n", sha1_to_hex(p->item->sha1), p->name);
137 }
138
139 static void show_edge(struct commit *commit)
140 {
141         printf("-%s\n", sha1_to_hex(commit->object.sha1));
142 }
143
144 /*
145  * This is a truly stupid algorithm, but it's only
146  * used for bisection, and we just don't care enough.
147  *
148  * We care just barely enough to avoid recursing for
149  * non-merge entries.
150  */
151 static int count_distance(struct commit_list *entry)
152 {
153         int nr = 0;
154
155         while (entry) {
156                 struct commit *commit = entry->item;
157                 struct commit_list *p;
158
159                 if (commit->object.flags & (UNINTERESTING | COUNTED))
160                         break;
161                 if (!(commit->object.flags & TREESAME))
162                         nr++;
163                 commit->object.flags |= COUNTED;
164                 p = commit->parents;
165                 entry = p;
166                 if (p) {
167                         p = p->next;
168                         while (p) {
169                                 nr += count_distance(p);
170                                 p = p->next;
171                         }
172                 }
173         }
174
175         return nr;
176 }
177
178 static void clear_distance(struct commit_list *list)
179 {
180         while (list) {
181                 struct commit *commit = list->item;
182                 commit->object.flags &= ~COUNTED;
183                 list = list->next;
184         }
185 }
186
187 #define DEBUG_BISECT 0
188
189 static inline int weight(struct commit_list *elem)
190 {
191         return *((int*)(elem->item->util));
192 }
193
194 static inline void weight_set(struct commit_list *elem, int weight)
195 {
196         *((int*)(elem->item->util)) = weight;
197 }
198
199 static int count_interesting_parents(struct commit *commit)
200 {
201         struct commit_list *p;
202         int count;
203
204         for (count = 0, p = commit->parents; p; p = p->next) {
205                 if (p->item->object.flags & UNINTERESTING)
206                         continue;
207                 count++;
208         }
209         return count;
210 }
211
212 static inline int halfway(struct commit_list *p, int nr)
213 {
214         /*
215          * Don't short-cut something we are not going to return!
216          */
217         if (p->item->object.flags & TREESAME)
218                 return 0;
219         if (DEBUG_BISECT)
220                 return 0;
221         /*
222          * 2 and 3 are halfway of 5.
223          * 3 is halfway of 6 but 2 and 4 are not.
224          */
225         switch (2 * weight(p) - nr) {
226         case -1: case 0: case 1:
227                 return 1;
228         default:
229                 return 0;
230         }
231 }
232
233 #if !DEBUG_BISECT
234 #define show_list(a,b,c,d) do { ; } while (0)
235 #else
236 static void show_list(const char *debug, int counted, int nr,
237                       struct commit_list *list)
238 {
239         struct commit_list *p;
240
241         fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr);
242
243         for (p = list; p; p = p->next) {
244                 struct commit_list *pp;
245                 struct commit *commit = p->item;
246                 unsigned flags = commit->object.flags;
247                 enum object_type type;
248                 unsigned long size;
249                 char *buf = read_sha1_file(commit->object.sha1, &type, &size);
250                 char *ep, *sp;
251
252                 fprintf(stderr, "%c%c%c ",
253                         (flags & TREESAME) ? ' ' : 'T',
254                         (flags & UNINTERESTING) ? 'U' : ' ',
255                         (flags & COUNTED) ? 'C' : ' ');
256                 if (commit->util)
257                         fprintf(stderr, "%3d", weight(p));
258                 else
259                         fprintf(stderr, "---");
260                 fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1));
261                 for (pp = commit->parents; pp; pp = pp->next)
262                         fprintf(stderr, " %.*s", 8,
263                                 sha1_to_hex(pp->item->object.sha1));
264
265                 sp = strstr(buf, "\n\n");
266                 if (sp) {
267                         sp += 2;
268                         for (ep = sp; *ep && *ep != '\n'; ep++)
269                                 ;
270                         fprintf(stderr, " %.*s", (int)(ep - sp), sp);
271                 }
272                 fprintf(stderr, "\n");
273         }
274 }
275 #endif /* DEBUG_BISECT */
276
277 static struct commit_list *best_bisection(struct commit_list *list, int nr)
278 {
279         struct commit_list *p, *best;
280         int best_distance = -1;
281
282         best = list;
283         for (p = list; p; p = p->next) {
284                 int distance;
285                 unsigned flags = p->item->object.flags;
286
287                 if (flags & TREESAME)
288                         continue;
289                 distance = weight(p);
290                 if (nr - distance < distance)
291                         distance = nr - distance;
292                 if (distance > best_distance) {
293                         best = p;
294                         best_distance = distance;
295                 }
296         }
297
298         return best;
299 }
300
301 struct commit_dist {
302         struct commit *commit;
303         int distance;
304 };
305
306 static int compare_commit_dist(const void *a_, const void *b_)
307 {
308         struct commit_dist *a, *b;
309
310         a = (struct commit_dist *)a_;
311         b = (struct commit_dist *)b_;
312         if (a->distance != b->distance)
313                 return b->distance - a->distance; /* desc sort */
314         return hashcmp(a->commit->object.sha1, b->commit->object.sha1);
315 }
316
317 static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr)
318 {
319         struct commit_list *p;
320         struct commit_dist *array = xcalloc(nr, sizeof(*array));
321         int cnt, i;
322
323         for (p = list, cnt = 0; p; p = p->next) {
324                 int distance;
325                 unsigned flags = p->item->object.flags;
326
327                 if (flags & TREESAME)
328                         continue;
329                 distance = weight(p);
330                 if (nr - distance < distance)
331                         distance = nr - distance;
332                 array[cnt].commit = p->item;
333                 array[cnt].distance = distance;
334                 cnt++;
335         }
336         qsort(array, cnt, sizeof(*array), compare_commit_dist);
337         for (p = list, i = 0; i < cnt; i++) {
338                 struct name_decoration *r = xmalloc(sizeof(*r) + 100);
339                 struct object *obj = &(array[i].commit->object);
340
341                 sprintf(r->name, "dist=%d", array[i].distance);
342                 r->next = add_decoration(&name_decoration, obj, r);
343                 p->item = array[i].commit;
344                 p = p->next;
345         }
346         if (p)
347                 p->next = NULL;
348         free(array);
349         return list;
350 }
351
352 /*
353  * zero or positive weight is the number of interesting commits it can
354  * reach, including itself.  Especially, weight = 0 means it does not
355  * reach any tree-changing commits (e.g. just above uninteresting one
356  * but traversal is with pathspec).
357  *
358  * weight = -1 means it has one parent and its distance is yet to
359  * be computed.
360  *
361  * weight = -2 means it has more than one parent and its distance is
362  * unknown.  After running count_distance() first, they will get zero
363  * or positive distance.
364  */
365 static struct commit_list *do_find_bisection(struct commit_list *list,
366                                              int nr, int *weights,
367                                              int find_all)
368 {
369         int n, counted;
370         struct commit_list *p;
371
372         counted = 0;
373
374         for (n = 0, p = list; p; p = p->next) {
375                 struct commit *commit = p->item;
376                 unsigned flags = commit->object.flags;
377
378                 p->item->util = &weights[n++];
379                 switch (count_interesting_parents(commit)) {
380                 case 0:
381                         if (!(flags & TREESAME)) {
382                                 weight_set(p, 1);
383                                 counted++;
384                                 show_list("bisection 2 count one",
385                                           counted, nr, list);
386                         }
387                         /*
388                          * otherwise, it is known not to reach any
389                          * tree-changing commit and gets weight 0.
390                          */
391                         break;
392                 case 1:
393                         weight_set(p, -1);
394                         break;
395                 default:
396                         weight_set(p, -2);
397                         break;
398                 }
399         }
400
401         show_list("bisection 2 initialize", counted, nr, list);
402
403         /*
404          * If you have only one parent in the resulting set
405          * then you can reach one commit more than that parent
406          * can reach.  So we do not have to run the expensive
407          * count_distance() for single strand of pearls.
408          *
409          * However, if you have more than one parents, you cannot
410          * just add their distance and one for yourself, since
411          * they usually reach the same ancestor and you would
412          * end up counting them twice that way.
413          *
414          * So we will first count distance of merges the usual
415          * way, and then fill the blanks using cheaper algorithm.
416          */
417         for (p = list; p; p = p->next) {
418                 if (p->item->object.flags & UNINTERESTING)
419                         continue;
420                 if (weight(p) != -2)
421                         continue;
422                 weight_set(p, count_distance(p));
423                 clear_distance(list);
424
425                 /* Does it happen to be at exactly half-way? */
426                 if (!find_all && halfway(p, nr))
427                         return p;
428                 counted++;
429         }
430
431         show_list("bisection 2 count_distance", counted, nr, list);
432
433         while (counted < nr) {
434                 for (p = list; p; p = p->next) {
435                         struct commit_list *q;
436                         unsigned flags = p->item->object.flags;
437
438                         if (0 <= weight(p))
439                                 continue;
440                         for (q = p->item->parents; q; q = q->next) {
441                                 if (q->item->object.flags & UNINTERESTING)
442                                         continue;
443                                 if (0 <= weight(q))
444                                         break;
445                         }
446                         if (!q)
447                                 continue;
448
449                         /*
450                          * weight for p is unknown but q is known.
451                          * add one for p itself if p is to be counted,
452                          * otherwise inherit it from q directly.
453                          */
454                         if (!(flags & TREESAME)) {
455                                 weight_set(p, weight(q)+1);
456                                 counted++;
457                                 show_list("bisection 2 count one",
458                                           counted, nr, list);
459                         }
460                         else
461                                 weight_set(p, weight(q));
462
463                         /* Does it happen to be at exactly half-way? */
464                         if (!find_all && halfway(p, nr))
465                                 return p;
466                 }
467         }
468
469         show_list("bisection 2 counted all", counted, nr, list);
470
471         if (!find_all)
472                 return best_bisection(list, nr);
473         else
474                 return best_bisection_sorted(list, nr);
475 }
476
477 static struct commit_list *find_bisection(struct commit_list *list,
478                                           int *reaches, int *all,
479                                           int find_all)
480 {
481         int nr, on_list;
482         struct commit_list *p, *best, *next, *last;
483         int *weights;
484
485         show_list("bisection 2 entry", 0, 0, list);
486
487         /*
488          * Count the number of total and tree-changing items on the
489          * list, while reversing the list.
490          */
491         for (nr = on_list = 0, last = NULL, p = list;
492              p;
493              p = next) {
494                 unsigned flags = p->item->object.flags;
495
496                 next = p->next;
497                 if (flags & UNINTERESTING)
498                         continue;
499                 p->next = last;
500                 last = p;
501                 if (!(flags & TREESAME))
502                         nr++;
503                 on_list++;
504         }
505         list = last;
506         show_list("bisection 2 sorted", 0, nr, list);
507
508         *all = nr;
509         weights = xcalloc(on_list, sizeof(*weights));
510
511         /* Do the real work of finding bisection commit. */
512         best = do_find_bisection(list, nr, weights, find_all);
513         if (best) {
514                 if (!find_all)
515                         best->next = NULL;
516                 *reaches = weight(best);
517         }
518         free(weights);
519         return best;
520 }
521
522 static void read_revisions_from_stdin(struct rev_info *revs)
523 {
524         char line[1000];
525
526         while (fgets(line, sizeof(line), stdin) != NULL) {
527                 int len = strlen(line);
528                 if (len && line[len - 1] == '\n')
529                         line[--len] = 0;
530                 if (!len)
531                         break;
532                 if (line[0] == '-')
533                         die("options not supported in --stdin mode");
534                 if (handle_revision_arg(line, revs, 0, 1))
535                         die("bad revision '%s'", line);
536         }
537 }
538
539 int cmd_rev_list(int argc, const char **argv, const char *prefix)
540 {
541         struct commit_list *list;
542         int i;
543         int read_from_stdin = 0;
544         int bisect_show_vars = 0;
545         int bisect_find_all = 0;
546         int quiet = 0;
547
548         git_config(git_default_config);
549         init_revisions(&revs, prefix);
550         revs.abbrev = 0;
551         revs.commit_format = CMIT_FMT_UNSPECIFIED;
552         argc = setup_revisions(argc, argv, &revs, NULL);
553
554         for (i = 1 ; i < argc; i++) {
555                 const char *arg = argv[i];
556
557                 if (!strcmp(arg, "--header")) {
558                         revs.verbose_header = 1;
559                         continue;
560                 }
561                 if (!strcmp(arg, "--timestamp")) {
562                         show_timestamp = 1;
563                         continue;
564                 }
565                 if (!strcmp(arg, "--bisect")) {
566                         bisect_list = 1;
567                         continue;
568                 }
569                 if (!strcmp(arg, "--bisect-all")) {
570                         bisect_list = 1;
571                         bisect_find_all = 1;
572                         continue;
573                 }
574                 if (!strcmp(arg, "--bisect-vars")) {
575                         bisect_list = 1;
576                         bisect_show_vars = 1;
577                         continue;
578                 }
579                 if (!strcmp(arg, "--stdin")) {
580                         if (read_from_stdin++)
581                                 die("--stdin given twice?");
582                         read_revisions_from_stdin(&revs);
583                         continue;
584                 }
585                 if (!strcmp(arg, "--quiet")) {
586                         quiet = 1;
587                         continue;
588                 }
589                 usage(rev_list_usage);
590
591         }
592         if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
593                 /* The command line has a --pretty  */
594                 hdr_termination = '\n';
595                 if (revs.commit_format == CMIT_FMT_ONELINE)
596                         header_prefix = "";
597                 else
598                         header_prefix = "commit ";
599         }
600         else if (revs.verbose_header)
601                 /* Only --header was specified */
602                 revs.commit_format = CMIT_FMT_RAW;
603
604         list = revs.commits;
605
606         if ((!list &&
607              (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
608               !revs.pending.nr)) ||
609             revs.diff)
610                 usage(rev_list_usage);
611
612         save_commit_buffer = revs.verbose_header || revs.grep_filter;
613         if (bisect_list)
614                 revs.limited = 1;
615
616         if (prepare_revision_walk(&revs))
617                 die("revision walk setup failed");
618         if (revs.tree_objects)
619                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
620
621         if (bisect_list) {
622                 int reaches = reaches, all = all;
623
624                 revs.commits = find_bisection(revs.commits, &reaches, &all,
625                                               bisect_find_all);
626                 if (bisect_show_vars) {
627                         int cnt;
628                         char hex[41];
629                         if (!revs.commits)
630                                 return 1;
631                         /*
632                          * revs.commits can reach "reaches" commits among
633                          * "all" commits.  If it is good, then there are
634                          * (all-reaches) commits left to be bisected.
635                          * On the other hand, if it is bad, then the set
636                          * to bisect is "reaches".
637                          * A bisect set of size N has (N-1) commits further
638                          * to test, as we already know one bad one.
639                          */
640                         cnt = all - reaches;
641                         if (cnt < reaches)
642                                 cnt = reaches;
643                         strcpy(hex, sha1_to_hex(revs.commits->item->object.sha1));
644
645                         if (bisect_find_all) {
646                                 traverse_commit_list(&revs, show_commit, show_object);
647                                 printf("------\n");
648                         }
649
650                         printf("bisect_rev=%s\n"
651                                "bisect_nr=%d\n"
652                                "bisect_good=%d\n"
653                                "bisect_bad=%d\n"
654                                "bisect_all=%d\n",
655                                hex,
656                                cnt - 1,
657                                all - reaches - 1,
658                                reaches - 1,
659                                all);
660                         return 0;
661                 }
662         }
663
664         traverse_commit_list(&revs,
665                 quiet ? finish_commit : show_commit,
666                 quiet ? finish_object : show_object);
667
668         return 0;
669 }