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