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