Retire support for old environment variables.
[git/git.git] / show-branch.c
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1#include <stdlib.h>
2#include "cache.h"
3#include "commit.h"
4#include "refs.h"
5
6static const char show_branch_usage[] =
2f0f8b71 7"git-show-branch [--all] [--heads] [--tags] [--more=count] [--merge-base] [<refs>...]";
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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 {
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38 const char *head_name; /* which head's ancestor? */
39 int generation; /* how many parents away from head_name */
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40};
41
8e5dd22b 42/* Name the commit as nth generation ancestor of head_name;
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43 * we count only the first-parent relationship for naming purposes.
44 */
8e5dd22b 45static void name_commit(struct commit *commit, const char *head_name, int nth)
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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;
8e5dd22b 51 name->head_name = head_name;
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52 name->generation = nth;
53}
54
55/* Parent is the first parent of the commit. We may name it
8e5dd22b 56 * as (n+1)th generation ancestor of the same head_name as
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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)
8e5dd22b 68 name_commit(parent, commit_name->head_name,
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69 commit_name->generation + 1);
70}
71
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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
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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;
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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;
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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
8e5dd22b 195static void show_one_commit(struct commit *commit)
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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;
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205 if (name && name->head_name) {
206 printf("[%s", name->head_name);
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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
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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
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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;
628894b2 249 return append_ref(refname + 11, sha1);
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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{
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261 if (head) {
262 int orig_cnt = ref_name_cnt;
f76412ed 263 for_each_ref(append_head_ref);
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264 sort_ref_range(orig_cnt, ref_name_cnt);
265 }
266 if (tag) {
267 int orig_cnt = ref_name_cnt;
f76412ed 268 for_each_ref(append_tag_ref);
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269 sort_ref_range(orig_cnt, ref_name_cnt);
270 }
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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);
2f0f8b71 294 int exit_status = 1;
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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));
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302 exit_status = 0;
303 commit->object.flags |= UNINTERESTING;
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304 }
305 }
2f0f8b71 306 return exit_status;
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307}
308
309int main(int ac, char **av)
310{
311 struct commit *rev[MAX_REVS], *commit;
312 struct commit_list *list = NULL, *seen = NULL;
313 int num_rev, i, extra = 0;
314 int all_heads = 0, all_tags = 0;
8e5dd22b 315 int all_mask, all_revs, shown_merge_point;
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316 char head_path[128];
317 int head_path_len;
318 unsigned char head_sha1[20];
319 int merge_base = 0;
f5e375c9 320 char **label;
f76412ed 321
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322 setup_git_directory();
323
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324 while (1 < ac && av[1][0] == '-') {
325 char *arg = av[1];
326 if (!strcmp(arg, "--all"))
327 all_heads = all_tags = 1;
328 else if (!strcmp(arg, "--heads"))
329 all_heads = 1;
330 else if (!strcmp(arg, "--tags"))
331 all_tags = 1;
332 else if (!strcmp(arg, "--more"))
333 extra = 1;
334 else if (!strncmp(arg, "--more=", 7)) {
335 extra = atoi(arg + 7);
336 if (extra < 0)
337 usage(show_branch_usage);
338 }
339 else if (!strcmp(arg, "--merge-base"))
340 merge_base = 1;
341 else
342 usage(show_branch_usage);
343 ac--; av++;
344 }
345 ac--; av++;
346
347 if (all_heads + all_tags)
348 snarf_refs(all_heads, all_tags);
349
350 while (0 < ac) {
351 unsigned char revkey[20];
352 if (get_sha1(*av, revkey))
353 die("bad sha1 reference %s", *av);
354 append_ref(*av, revkey);
355 ac--; av++;
356 }
357
358 /* If still no revs, then add heads */
359 if (!ref_name_cnt)
360 snarf_refs(1, 0);
361
362 for (num_rev = 0; ref_name[num_rev]; num_rev++) {
363 unsigned char revkey[20];
364
365 if (MAX_REVS <= num_rev)
366 die("cannot handle more than %d revs.", MAX_REVS);
367 if (get_sha1(ref_name[num_rev], revkey))
368 usage(show_branch_usage);
369 commit = lookup_commit_reference(revkey);
370 if (!commit)
371 die("cannot find commit %s (%s)",
372 ref_name[num_rev], revkey);
373 parse_commit(commit);
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374 mark_seen(commit, &seen);
375
376 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
377 * and so on. REV_SHIFT bits from bit 0 are used for
378 * internal bookkeeping.
379 */
380 commit->object.flags |= 1u << (num_rev + REV_SHIFT);
381 insert_by_date(commit, &list);
382 rev[num_rev] = commit;
383 }
384 join_revs(&list, &seen, num_rev, extra);
385
386 head_path_len = readlink(".git/HEAD", head_path, sizeof(head_path)-1);
387 if ((head_path_len < 0) || get_sha1("HEAD", head_sha1))
388 head_path[0] = 0;
389 else
390 head_path[head_path_len] = 0;
391
392 if (merge_base)
393 return show_merge_base(seen, num_rev);
394
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395 /* Show list */
396 if (1 < num_rev) {
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397 for (i = 0; i < num_rev; i++) {
398 int j;
399 int is_head = rev_is_head(head_path,
400 head_path_len,
401 ref_name[i],
402 head_sha1,
403 rev[i]->object.sha1);
404 for (j = 0; j < i; j++)
405 putchar(' ');
406 printf("%c [%s] ", is_head ? '*' : '!', ref_name[i]);
8e5dd22b 407 show_one_commit(rev[i]);
f76412ed 408 }
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409 for (i = 0; i < num_rev; i++)
410 putchar('-');
411 putchar('\n');
412 }
413
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414 /* Sort topologically */
415 sort_in_topological_order(&seen);
416
417 /* Give names to commits */
418 name_commits(seen, rev, ref_name, num_rev);
419
420 all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
421 all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
422 shown_merge_point = 0;
423
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424 while (seen) {
425 struct commit *commit = pop_one_commit(&seen);
426 int this_flag = commit->object.flags;
8e5dd22b 427 int is_merge_point = (this_flag & all_revs) == all_revs;
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428 static char *obvious[] = { "" };
429
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430 if (is_merge_point)
431 shown_merge_point = 1;
432
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433 if (1 < num_rev) {
434 for (i = 0; i < num_rev; i++)
435 putchar((this_flag & (1u << (i + REV_SHIFT)))
436 ? '+' : ' ');
437 putchar(' ');
438 }
8e5dd22b 439 show_one_commit(commit);
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440 if (num_rev == 1)
441 label = obvious;
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442 if (shown_merge_point && is_merge_point)
443 if (--extra < 0)
444 break;
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445 }
446 return 0;
447}