1#include <stdlib.h>
2#include "cache.h"
3#include "commit.h"
4#include "refs.h"
5
6static const char show_branch_usage[] =
7"git-show-branch [--all] [--heads] [--tags] [--more=count | --list | --independent | --merge-base ] [<refs>...]";
8
9#define UNINTERESTING 01
10
11#define REV_SHIFT 2
12#define MAX_REVS 29 /* should not exceed bits_per_int - REV_SHIFT */
13
14static struct commit *interesting(struct commit_list *list)
15{
16 while (list) {
17 struct commit *commit = list->item;
18 list = list->next;
19 if (commit->object.flags & UNINTERESTING)
20 continue;
21 return commit;
22 }
23 return NULL;
24}
25
26static struct commit *pop_one_commit(struct commit_list **list_p)
27{
28 struct commit *commit;
29 struct commit_list *list;
30 list = *list_p;
31 commit = list->item;
32 *list_p = list->next;
33 free(list);
34 return commit;
35}
36
37struct commit_name {
38 const char *head_name; /* which head's ancestor? */
39 int generation; /* how many parents away from head_name */
40};
41
42/* Name the commit as nth generation ancestor of head_name;
43 * we count only the first-parent relationship for naming purposes.
44 */
45static void name_commit(struct commit *commit, const char *head_name, int nth)
46{
47 struct commit_name *name;
48 if (!commit->object.util)
49 commit->object.util = xmalloc(sizeof(struct commit_name));
50 name = commit->object.util;
51 name->head_name = head_name;
52 name->generation = nth;
53}
54
55/* Parent is the first parent of the commit. We may name it
56 * as (n+1)th generation ancestor of the same head_name as
57 * commit is nth generation ancestore of, if that generation
58 * number is better than the name it already has.
59 */
60static void name_parent(struct commit *commit, struct commit *parent)
61{
62 struct commit_name *commit_name = commit->object.util;
63 struct commit_name *parent_name = parent->object.util;
64 if (!commit_name)
65 return;
66 if (!parent_name ||
67 commit_name->generation + 1 < parent_name->generation)
68 name_commit(parent, commit_name->head_name,
69 commit_name->generation + 1);
70}
71
72static int name_first_parent_chain(struct commit *c)
73{
74 int i = 0;
75 while (c) {
76 struct commit *p;
77 if (!c->object.util)
78 break;
79 if (!c->parents)
80 break;
81 p = c->parents->item;
82 if (!p->object.util) {
83 name_parent(c, p);
84 i++;
85 }
86 c = p;
87 }
88 return i;
89}
90
91static void name_commits(struct commit_list *list,
92 struct commit **rev,
93 char **ref_name,
94 int num_rev)
95{
96 struct commit_list *cl;
97 struct commit *c;
98 int i;
99
100 /* First give names to the given heads */
101 for (cl = list; cl; cl = cl->next) {
102 c = cl->item;
103 if (c->object.util)
104 continue;
105 for (i = 0; i < num_rev; i++) {
106 if (rev[i] == c) {
107 name_commit(c, ref_name[i], 0);
108 break;
109 }
110 }
111 }
112
113 /* Then commits on the first parent ancestry chain */
114 do {
115 i = 0;
116 for (cl = list; cl; cl = cl->next) {
117 i += name_first_parent_chain(cl->item);
118 }
119 } while (i);
120
121 /* Finally, any unnamed commits */
122 do {
123 i = 0;
124 for (cl = list; cl; cl = cl->next) {
125 struct commit_list *parents;
126 struct commit_name *n;
127 int nth;
128 c = cl->item;
129 if (!c->object.util)
130 continue;
131 n = c->object.util;
132 parents = c->parents;
133 nth = 0;
134 while (parents) {
135 struct commit *p = parents->item;
136 char newname[1000];
137 parents = parents->next;
138 nth++;
139 if (p->object.util)
140 continue;
141 sprintf(newname, "%s^%d", n->head_name, nth);
142 name_commit(p, strdup(newname), 0);
143 i++;
144 name_first_parent_chain(p);
145 }
146 }
147 } while (i);
148}
149
150static int mark_seen(struct commit *commit, struct commit_list **seen_p)
151{
152 if (!commit->object.flags) {
153 insert_by_date(commit, seen_p);
154 return 1;
155 }
156 return 0;
157}
158
159static void join_revs(struct commit_list **list_p,
160 struct commit_list **seen_p,
161 int num_rev, int extra)
162{
163 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
164 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
165
166 while (*list_p) {
167 struct commit_list *parents;
168 struct commit *commit = pop_one_commit(list_p);
169 int flags = commit->object.flags & all_mask;
170 int still_interesting = !!interesting(*list_p);
171
172 if (!still_interesting && extra < 0)
173 break;
174
175 mark_seen(commit, seen_p);
176 if ((flags & all_revs) == all_revs)
177 flags |= UNINTERESTING;
178 parents = commit->parents;
179
180 while (parents) {
181 struct commit *p = parents->item;
182 int this_flag = p->object.flags;
183 parents = parents->next;
184 if ((this_flag & flags) == flags)
185 continue;
186 parse_commit(p);
187 if (mark_seen(p, seen_p) && !still_interesting)
188 extra--;
189 p->object.flags |= flags;
190 insert_by_date(p, list_p);
191 }
192 }
193}
194
195static void show_one_commit(struct commit *commit)
196{
197 char pretty[128], *cp;
198 struct commit_name *name = commit->object.util;
199 pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
200 pretty, sizeof(pretty));
201 if (!strncmp(pretty, "[PATCH] ", 8))
202 cp = pretty + 8;
203 else
204 cp = pretty;
205 if (name && name->head_name) {
206 printf("[%s", name->head_name);
207 if (name->generation)
208 printf("~%d", name->generation);
209 printf("] ");
210 }
211 puts(cp);
212}
213
214static char *ref_name[MAX_REVS + 1];
215static int ref_name_cnt;
216
217static int compare_ref_name(const void *a_, const void *b_)
218{
219 const char * const*a = a_, * const*b = b_;
220 return strcmp(*a, *b);
221}
222
223static void sort_ref_range(int bottom, int top)
224{
225 qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
226 compare_ref_name);
227}
228
229static int append_ref(const char *refname, const unsigned char *sha1)
230{
231 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
232 if (!commit)
233 return 0;
234 if (MAX_REVS < ref_name_cnt) {
235 fprintf(stderr, "warning: ignoring %s; "
236 "cannot handle more than %d refs",
237 refname, MAX_REVS);
238 return 0;
239 }
240 ref_name[ref_name_cnt++] = strdup(refname);
241 ref_name[ref_name_cnt] = NULL;
242 return 0;
243}
244
245static int append_head_ref(const char *refname, const unsigned char *sha1)
246{
247 if (strncmp(refname, "refs/heads/", 11))
248 return 0;
249 return append_ref(refname + 11, sha1);
250}
251
252static int append_tag_ref(const char *refname, const unsigned char *sha1)
253{
254 if (strncmp(refname, "refs/tags/", 10))
255 return 0;
256 return append_ref(refname + 5, sha1);
257}
258
259static void snarf_refs(int head, int tag)
260{
261 if (head) {
262 int orig_cnt = ref_name_cnt;
263 for_each_ref(append_head_ref);
264 sort_ref_range(orig_cnt, ref_name_cnt);
265 }
266 if (tag) {
267 int orig_cnt = ref_name_cnt;
268 for_each_ref(append_tag_ref);
269 sort_ref_range(orig_cnt, ref_name_cnt);
270 }
271}
272
273static int rev_is_head(char *head_path, int headlen,
274 char *name,
275 unsigned char *head_sha1, unsigned char *sha1)
276{
277 int namelen;
278 if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
279 return 0;
280 namelen = strlen(name);
281 if ((headlen < namelen) ||
282 memcmp(head_path + headlen - namelen, name, namelen))
283 return 0;
284 if (headlen == namelen ||
285 head_path[headlen - namelen - 1] == '/')
286 return 1;
287 return 0;
288}
289
290static int show_merge_base(struct commit_list *seen, int num_rev)
291{
292 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
293 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
294 int exit_status = 1;
295
296 while (seen) {
297 struct commit *commit = pop_one_commit(&seen);
298 int flags = commit->object.flags & all_mask;
299 if (!(flags & UNINTERESTING) &&
300 ((flags & all_revs) == all_revs)) {
301 puts(sha1_to_hex(commit->object.sha1));
302 exit_status = 0;
303 commit->object.flags |= UNINTERESTING;
304 }
305 }
306 return exit_status;
307}
308
309static int show_independent(struct commit **rev,
310 int num_rev,
311 char **ref_name,
312 unsigned int *rev_mask)
313{
314 int i;
315
316 for (i = 0; i < num_rev; i++) {
317 struct commit *commit = rev[i];
318 unsigned int flag = rev_mask[i];
319
320 if (commit->object.flags == flag)
321 puts(sha1_to_hex(commit->object.sha1));
322 commit->object.flags |= UNINTERESTING;
323 }
324 return 0;
325}
326
327int main(int ac, char **av)
328{
329 struct commit *rev[MAX_REVS], *commit;
330 struct commit_list *list = NULL, *seen = NULL;
331 unsigned int rev_mask[MAX_REVS];
332 int num_rev, i, extra = 0;
333 int all_heads = 0, all_tags = 0;
334 int all_mask, all_revs, shown_merge_point;
335 char head_path[128];
336 int head_path_len;
337 unsigned char head_sha1[20];
338 int merge_base = 0;
339 int independent = 0;
340 char **label;
341
342 setup_git_directory();
343
344 while (1 < ac && av[1][0] == '-') {
345 char *arg = av[1];
346 if (!strcmp(arg, "--all"))
347 all_heads = all_tags = 1;
348 else if (!strcmp(arg, "--heads"))
349 all_heads = 1;
350 else if (!strcmp(arg, "--tags"))
351 all_tags = 1;
352 else if (!strcmp(arg, "--more"))
353 extra = 1;
354 else if (!strcmp(arg, "--list"))
355 extra = -1;
356 else if (!strncmp(arg, "--more=", 7))
357 extra = atoi(arg + 7);
358 else if (!strcmp(arg, "--merge-base"))
359 merge_base = 1;
360 else if (!strcmp(arg, "--independent"))
361 independent = 1;
362 else
363 usage(show_branch_usage);
364 ac--; av++;
365 }
366 ac--; av++;
367
368 /* Only one of these is allowed */
369 if (1 < independent + merge_base + (extra != 0))
370 usage(show_branch_usage);
371
372 if (all_heads + all_tags)
373 snarf_refs(all_heads, all_tags);
374
375 while (0 < ac) {
376 unsigned char revkey[20];
377 if (get_sha1(*av, revkey))
378 die("bad sha1 reference %s", *av);
379 append_ref(*av, revkey);
380 ac--; av++;
381 }
382
383 /* If still no revs, then add heads */
384 if (!ref_name_cnt)
385 snarf_refs(1, 0);
386
387 for (num_rev = 0; ref_name[num_rev]; num_rev++) {
388 unsigned char revkey[20];
389 unsigned int flag = 1u << (num_rev + REV_SHIFT);
390
391 if (MAX_REVS <= num_rev)
392 die("cannot handle more than %d revs.", MAX_REVS);
393 if (get_sha1(ref_name[num_rev], revkey))
394 usage(show_branch_usage);
395 commit = lookup_commit_reference(revkey);
396 if (!commit)
397 die("cannot find commit %s (%s)",
398 ref_name[num_rev], revkey);
399 parse_commit(commit);
400 mark_seen(commit, &seen);
401
402 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
403 * and so on. REV_SHIFT bits from bit 0 are used for
404 * internal bookkeeping.
405 */
406 commit->object.flags |= flag;
407 if (commit->object.flags == flag)
408 insert_by_date(commit, &list);
409 rev[num_rev] = commit;
410 }
411 for (i = 0; i < num_rev; i++)
412 rev_mask[i] = rev[i]->object.flags;
413
414 if (0 <= extra)
415 join_revs(&list, &seen, num_rev, extra);
416
417 head_path_len = readlink(".git/HEAD", head_path, sizeof(head_path)-1);
418 if ((head_path_len < 0) || get_sha1("HEAD", head_sha1))
419 head_path[0] = 0;
420 else
421 head_path[head_path_len] = 0;
422
423 if (merge_base)
424 return show_merge_base(seen, num_rev);
425
426 if (independent)
427 return show_independent(rev, num_rev, ref_name, rev_mask);
428
429 /* Show list; --more=-1 means list-only */
430 if (1 < num_rev || extra < 0) {
431 for (i = 0; i < num_rev; i++) {
432 int j;
433 int is_head = rev_is_head(head_path,
434 head_path_len,
435 ref_name[i],
436 head_sha1,
437 rev[i]->object.sha1);
438 if (extra < 0)
439 printf("%c [%s] ",
440 is_head ? '*' : ' ', ref_name[i]);
441 else {
442 for (j = 0; j < i; j++)
443 putchar(' ');
444 printf("%c [%s] ",
445 is_head ? '*' : '!', ref_name[i]);
446 }
447 show_one_commit(rev[i]);
448 }
449 if (0 <= extra) {
450 for (i = 0; i < num_rev; i++)
451 putchar('-');
452 putchar('\n');
453 }
454 }
455 if (extra < 0)
456 exit(0);
457
458 /* Sort topologically */
459 sort_in_topological_order(&seen);
460
461 /* Give names to commits */
462 name_commits(seen, rev, ref_name, num_rev);
463
464 all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
465 all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
466 shown_merge_point = 0;
467
468 while (seen) {
469 struct commit *commit = pop_one_commit(&seen);
470 int this_flag = commit->object.flags;
471 int is_merge_point = (this_flag & all_revs) == all_revs;
472 static char *obvious[] = { "" };
473
474 if (is_merge_point)
475 shown_merge_point = 1;
476
477 if (1 < num_rev) {
478 for (i = 0; i < num_rev; i++)
479 putchar((this_flag & (1u << (i + REV_SHIFT)))
480 ? '+' : ' ');
481 putchar(' ');
482 }
483 show_one_commit(commit);
484 if (num_rev == 1)
485 label = obvious;
486 if (shown_merge_point && is_merge_point)
487 if (--extra < 0)
488 break;
489 }
490 return 0;
491}