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 char *buf = NULL;
84 unsigned long buflen = 0;
85 pretty_print_commit(revs.commit_format, commit, ~0,
86 &buf, &buflen,
87 revs.abbrev, NULL, NULL, revs.date_mode);
88 printf("%s%c", buf, hdr_termination);
89 free(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 distance, 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 distance *= 2;
206 switch (distance - nr) {
207 case -1: case 0: case 1:
208 return 1;
209 default:
210 return 0;
211 }
212}
213#if !DEBUG_BISECT
215#define show_list(a,b,c,d) do { ; } while (0)
216#else
217static void show_list(const char *debug, int counted, int nr,
218 struct commit_list *list)
219{
220 struct commit_list *p;
221 fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr);
223 for (p = list; p; p = p->next) {
225 struct commit_list *pp;
226 struct commit *commit = p->item;
227 unsigned flags = commit->object.flags;
228 enum object_type type;
229 unsigned long size;
230 char *buf = read_sha1_file(commit->object.sha1, &type, &size);
231 char *ep, *sp;
232 fprintf(stderr, "%c%c%c ",
234 (flags & TREECHANGE) ? 'T' : ' ',
235 (flags & UNINTERESTING) ? 'U' : ' ',
236 (flags & COUNTED) ? 'C' : ' ');
237 if (commit->util)
238 fprintf(stderr, "%3d", weight(p));
239 else
240 fprintf(stderr, "---");
241 fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1));
242 for (pp = commit->parents; pp; pp = pp->next)
243 fprintf(stderr, " %.*s", 8,
244 sha1_to_hex(pp->item->object.sha1));
245 sp = strstr(buf, "\n\n");
247 if (sp) {
248 sp += 2;
249 for (ep = sp; *ep && *ep != '\n'; ep++)
250 ;
251 fprintf(stderr, " %.*s", (int)(ep - sp), sp);
252 }
253 fprintf(stderr, "\n");
254 }
255}
256#endif /* DEBUG_BISECT */
257/*
259 * zero or positive weight is the number of interesting commits it can
260 * reach, including itself. Especially, weight = 0 means it does not
261 * reach any tree-changing commits (e.g. just above uninteresting one
262 * but traversal is with pathspec).
263 *
264 * weight = -1 means it has one parent and its distance is yet to
265 * be computed.
266 *
267 * weight = -2 means it has more than one parent and its distance is
268 * unknown. After running count_distance() first, they will get zero
269 * or positive distance.
270 */
271static struct commit_list *do_find_bisection(struct commit_list *list,
272 int nr, int *weights)
273{
274 int n, counted, distance;
275 struct commit_list *p, *best;
276 counted = 0;
278 for (n = 0, p = list; p; p = p->next) {
280 struct commit *commit = p->item;
281 unsigned flags = commit->object.flags;
282 p->item->util = &weights[n++];
284 switch (count_interesting_parents(commit)) {
285 case 0:
286 if (!revs.prune_fn || (flags & TREECHANGE)) {
287 weight_set(p, 1);
288 counted++;
289 show_list("bisection 2 count one",
290 counted, nr, list);
291 }
292 /*
293 * otherwise, it is known not to reach any
294 * tree-changing commit and gets weight 0.
295 */
296 break;
297 case 1:
298 weight_set(p, -1);
299 break;
300 default:
301 weight_set(p, -2);
302 break;
303 }
304 }
305 show_list("bisection 2 initialize", counted, nr, list);
307 /*
309 * If you have only one parent in the resulting set
310 * then you can reach one commit more than that parent
311 * can reach. So we do not have to run the expensive
312 * count_distance() for single strand of pearls.
313 *
314 * However, if you have more than one parents, you cannot
315 * just add their distance and one for yourself, since
316 * they usually reach the same ancestor and you would
317 * end up counting them twice that way.
318 *
319 * So we will first count distance of merges the usual
320 * way, and then fill the blanks using cheaper algorithm.
321 */
322 for (p = list; p; p = p->next) {
323 if (p->item->object.flags & UNINTERESTING)
324 continue;
325 n = weight(p);
326 if (n != -2)
327 continue;
328 distance = count_distance(p);
329 clear_distance(list);
330 weight_set(p, distance);
331 /* Does it happen to be at exactly half-way? */
333 if (halfway(p, distance, nr))
334 return p;
335 counted++;
336 }
337 show_list("bisection 2 count_distance", counted, nr, list);
339 while (counted < nr) {
341 for (p = list; p; p = p->next) {
342 struct commit_list *q;
343 unsigned flags = p->item->object.flags;
344 if (0 <= weight(p))
346 continue;
347 for (q = p->item->parents; q; q = q->next) {
348 if (q->item->object.flags & UNINTERESTING)
349 continue;
350 if (0 <= weight(q))
351 break;
352 }
353 if (!q)
354 continue;
355 /*
357 * weight for p is unknown but q is known.
358 * add one for p itself if p is to be counted,
359 * otherwise inherit it from q directly.
360 */
361 if (!revs.prune_fn || (flags & TREECHANGE)) {
362 weight_set(p, weight(q)+1);
363 counted++;
364 show_list("bisection 2 count one",
365 counted, nr, list);
366 }
367 else
368 weight_set(p, weight(q));
369 /* Does it happen to be at exactly half-way? */
371 distance = weight(p);
372 if (halfway(p, distance, nr))
373 return p;
374 }
375 }
376 show_list("bisection 2 counted all", counted, nr, list);
378 /* Then find the best one */
380 counted = -1;
381 best = list;
382 for (p = list; p; p = p->next) {
383 unsigned flags = p->item->object.flags;
384 if (revs.prune_fn && !(flags & TREECHANGE))
386 continue;
387 distance = weight(p);
388 if (nr - distance < distance)
389 distance = nr - distance;
390 if (distance > counted) {
391 best = p;
392 counted = distance;
393 }
394 }
395 return best;
396}
397static struct commit_list *find_bisection(struct commit_list *list,
399 int *reaches, int *all)
400{
401 int nr, on_list;
402 struct commit_list *p, *best, *next, *last;
403 int *weights;
404 show_list("bisection 2 entry", 0, 0, list);
406 /*
408 * Count the number of total and tree-changing items on the
409 * list, while reversing the list.
410 */
411 for (nr = on_list = 0, last = NULL, p = list;
412 p;
413 p = next) {
414 unsigned flags = p->item->object.flags;
415 next = p->next;
417 if (flags & UNINTERESTING)
418 continue;
419 p->next = last;
420 last = p;
421 if (!revs.prune_fn || (flags & TREECHANGE))
422 nr++;
423 on_list++;
424 }
425 list = last;
426 show_list("bisection 2 sorted", 0, nr, list);
427 *all = nr;
429 weights = xcalloc(on_list, sizeof(*weights));
430 /* Do the real work of finding bisection commit. */
432 best = do_find_bisection(list, nr, weights);
433 if (best)
435 best->next = NULL;
436 *reaches = weight(best);
438 free(weights);
439 return best;
441}
442static void read_revisions_from_stdin(struct rev_info *revs)
444{
445 char line[1000];
446 while (fgets(line, sizeof(line), stdin) != NULL) {
448 int len = strlen(line);
449 if (line[len - 1] == '\n')
450 line[--len] = 0;
451 if (!len)
452 break;
453 if (line[0] == '-')
454 die("options not supported in --stdin mode");
455 if (handle_revision_arg(line, revs, 0, 1))
456 die("bad revision '%s'", line);
457 }
458}
459int cmd_rev_list(int argc, const char **argv, const char *prefix)
461{
462 struct commit_list *list;
463 int i;
464 int read_from_stdin = 0;
465 int bisect_show_vars = 0;
466 git_config(git_default_config);
468 init_revisions(&revs, prefix);
469 revs.abbrev = 0;
470 revs.commit_format = CMIT_FMT_UNSPECIFIED;
471 argc = setup_revisions(argc, argv, &revs, NULL);
472 for (i = 1 ; i < argc; i++) {
474 const char *arg = argv[i];
475 if (!strcmp(arg, "--header")) {
477 revs.verbose_header = 1;
478 continue;
479 }
480 if (!strcmp(arg, "--timestamp")) {
481 show_timestamp = 1;
482 continue;
483 }
484 if (!strcmp(arg, "--bisect")) {
485 bisect_list = 1;
486 continue;
487 }
488 if (!strcmp(arg, "--bisect-vars")) {
489 bisect_list = 1;
490 bisect_show_vars = 1;
491 continue;
492 }
493 if (!strcmp(arg, "--stdin")) {
494 if (read_from_stdin++)
495 die("--stdin given twice?");
496 read_revisions_from_stdin(&revs);
497 continue;
498 }
499 usage(rev_list_usage);
500 }
502 if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
503 /* The command line has a --pretty */
504 hdr_termination = '\n';
505 if (revs.commit_format == CMIT_FMT_ONELINE)
506 header_prefix = "";
507 else
508 header_prefix = "commit ";
509 }
510 else if (revs.verbose_header)
511 /* Only --header was specified */
512 revs.commit_format = CMIT_FMT_RAW;
513 list = revs.commits;
515 if ((!list &&
517 (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
518 !revs.pending.nr)) ||
519 revs.diff)
520 usage(rev_list_usage);
521 save_commit_buffer = revs.verbose_header || revs.grep_filter;
523 track_object_refs = 0;
524 if (bisect_list)
525 revs.limited = 1;
526 prepare_revision_walk(&revs);
528 if (revs.tree_objects)
529 mark_edges_uninteresting(revs.commits, &revs, show_edge);
530 if (bisect_list) {
532 int reaches = reaches, all = all;
533 revs.commits = find_bisection(revs.commits, &reaches, &all);
535 if (bisect_show_vars) {
536 int cnt;
537 if (!revs.commits)
538 return 1;
539 /*
540 * revs.commits can reach "reaches" commits among
541 * "all" commits. If it is good, then there are
542 * (all-reaches) commits left to be bisected.
543 * On the other hand, if it is bad, then the set
544 * to bisect is "reaches".
545 * A bisect set of size N has (N-1) commits further
546 * to test, as we already know one bad one.
547 */
548 cnt = all-reaches;
549 if (cnt < reaches)
550 cnt = reaches;
551 printf("bisect_rev=%s\n"
552 "bisect_nr=%d\n"
553 "bisect_good=%d\n"
554 "bisect_bad=%d\n"
555 "bisect_all=%d\n",
556 sha1_to_hex(revs.commits->item->object.sha1),
557 cnt - 1,
558 all - reaches - 1,
559 reaches - 1,
560 all);
561 return 0;
562 }
563 }
564 traverse_commit_list(&revs, show_commit, show_object);
566 return 0;
568}