notes: implement helpers needed for note copying during rewrite
[git] / builtin-describe.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "tag.h"
4 #include "refs.h"
5 #include "builtin.h"
6 #include "exec_cmd.h"
7 #include "parse-options.h"
8 #include "diff.h"
9
10 #define SEEN            (1u<<0)
11 #define MAX_TAGS        (FLAG_BITS - 1)
12
13 static const char * const describe_usage[] = {
14         "git describe [options] <committish>*",
15         "git describe [options] --dirty",
16         NULL
17 };
18
19 static int debug;       /* Display lots of verbose info */
20 static int all; /* Any valid ref can be used */
21 static int tags;        /* Allow lightweight tags */
22 static int longformat;
23 static int abbrev = DEFAULT_ABBREV;
24 static int max_candidates = 10;
25 static int found_names;
26 static const char *pattern;
27 static int always;
28 static const char *dirty;
29
30 /* diff-index command arguments to check if working tree is dirty. */
31 static const char *diff_index_args[] = {
32         "diff-index", "--quiet", "HEAD", "--", NULL
33 };
34
35
36 struct commit_name {
37         struct tag *tag;
38         int prio; /* annotated tag = 2, tag = 1, head = 0 */
39         unsigned char sha1[20];
40         char path[FLEX_ARRAY]; /* more */
41 };
42 static const char *prio_names[] = {
43         "head", "lightweight", "annotated",
44 };
45
46 static void add_to_known_names(const char *path,
47                                struct commit *commit,
48                                int prio,
49                                const unsigned char *sha1)
50 {
51         struct commit_name *e = commit->util;
52         if (!e || e->prio < prio) {
53                 size_t len = strlen(path)+1;
54                 free(e);
55                 e = xmalloc(sizeof(struct commit_name) + len);
56                 e->tag = NULL;
57                 e->prio = prio;
58                 hashcpy(e->sha1, sha1);
59                 memcpy(e->path, path, len);
60                 commit->util = e;
61         }
62         found_names = 1;
63 }
64
65 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
66 {
67         int might_be_tag = !prefixcmp(path, "refs/tags/");
68         struct commit *commit;
69         struct object *object;
70         unsigned char peeled[20];
71         int is_tag, prio;
72
73         if (!all && !might_be_tag)
74                 return 0;
75
76         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
77                 commit = lookup_commit_reference_gently(peeled, 1);
78                 if (!commit)
79                         return 0;
80                 is_tag = !!hashcmp(sha1, commit->object.sha1);
81         } else {
82                 commit = lookup_commit_reference_gently(sha1, 1);
83                 object = parse_object(sha1);
84                 if (!commit || !object)
85                         return 0;
86                 is_tag = object->type == OBJ_TAG;
87         }
88
89         /* If --all, then any refs are used.
90          * If --tags, then any tags are used.
91          * Otherwise only annotated tags are used.
92          */
93         if (might_be_tag) {
94                 if (is_tag)
95                         prio = 2;
96                 else
97                         prio = 1;
98
99                 if (pattern && fnmatch(pattern, path + 10, 0))
100                         prio = 0;
101         }
102         else
103                 prio = 0;
104
105         if (!all) {
106                 if (!prio)
107                         return 0;
108         }
109         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
110         return 0;
111 }
112
113 struct possible_tag {
114         struct commit_name *name;
115         int depth;
116         int found_order;
117         unsigned flag_within;
118 };
119
120 static int compare_pt(const void *a_, const void *b_)
121 {
122         struct possible_tag *a = (struct possible_tag *)a_;
123         struct possible_tag *b = (struct possible_tag *)b_;
124         if (a->depth != b->depth)
125                 return a->depth - b->depth;
126         if (a->found_order != b->found_order)
127                 return a->found_order - b->found_order;
128         return 0;
129 }
130
131 static unsigned long finish_depth_computation(
132         struct commit_list **list,
133         struct possible_tag *best)
134 {
135         unsigned long seen_commits = 0;
136         while (*list) {
137                 struct commit *c = pop_commit(list);
138                 struct commit_list *parents = c->parents;
139                 seen_commits++;
140                 if (c->object.flags & best->flag_within) {
141                         struct commit_list *a = *list;
142                         while (a) {
143                                 struct commit *i = a->item;
144                                 if (!(i->object.flags & best->flag_within))
145                                         break;
146                                 a = a->next;
147                         }
148                         if (!a)
149                                 break;
150                 } else
151                         best->depth++;
152                 while (parents) {
153                         struct commit *p = parents->item;
154                         parse_commit(p);
155                         if (!(p->object.flags & SEEN))
156                                 insert_by_date(p, list);
157                         p->object.flags |= c->object.flags;
158                         parents = parents->next;
159                 }
160         }
161         return seen_commits;
162 }
163
164 static void display_name(struct commit_name *n)
165 {
166         if (n->prio == 2 && !n->tag) {
167                 n->tag = lookup_tag(n->sha1);
168                 if (!n->tag || parse_tag(n->tag) || !n->tag->tag)
169                         die("annotated tag %s not available", n->path);
170                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
171                         warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
172         }
173
174         if (n->tag)
175                 printf("%s", n->tag->tag);
176         else
177                 printf("%s", n->path);
178 }
179
180 static void show_suffix(int depth, const unsigned char *sha1)
181 {
182         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
183 }
184
185 static void describe(const char *arg, int last_one)
186 {
187         unsigned char sha1[20];
188         struct commit *cmit, *gave_up_on = NULL;
189         struct commit_list *list;
190         struct commit_name *n;
191         struct possible_tag all_matches[MAX_TAGS];
192         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
193         unsigned long seen_commits = 0;
194         unsigned int unannotated_cnt = 0;
195
196         if (get_sha1(arg, sha1))
197                 die("Not a valid object name %s", arg);
198         cmit = lookup_commit_reference(sha1);
199         if (!cmit)
200                 die("%s is not a valid '%s' object", arg, commit_type);
201
202         n = cmit->util;
203         if (n && (tags || all || n->prio == 2)) {
204                 /*
205                  * Exact match to an existing ref.
206                  */
207                 display_name(n);
208                 if (longformat)
209                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
210                 if (dirty)
211                         printf("%s", dirty);
212                 printf("\n");
213                 return;
214         }
215
216         if (!max_candidates)
217                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
218         if (debug)
219                 fprintf(stderr, "searching to describe %s\n", arg);
220
221         list = NULL;
222         cmit->object.flags = SEEN;
223         commit_list_insert(cmit, &list);
224         while (list) {
225                 struct commit *c = pop_commit(&list);
226                 struct commit_list *parents = c->parents;
227                 seen_commits++;
228                 n = c->util;
229                 if (n) {
230                         if (!tags && !all && n->prio < 2) {
231                                 unannotated_cnt++;
232                         } else if (match_cnt < max_candidates) {
233                                 struct possible_tag *t = &all_matches[match_cnt++];
234                                 t->name = n;
235                                 t->depth = seen_commits - 1;
236                                 t->flag_within = 1u << match_cnt;
237                                 t->found_order = match_cnt;
238                                 c->object.flags |= t->flag_within;
239                                 if (n->prio == 2)
240                                         annotated_cnt++;
241                         }
242                         else {
243                                 gave_up_on = c;
244                                 break;
245                         }
246                 }
247                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
248                         struct possible_tag *t = &all_matches[cur_match];
249                         if (!(c->object.flags & t->flag_within))
250                                 t->depth++;
251                 }
252                 if (annotated_cnt && !list) {
253                         if (debug)
254                                 fprintf(stderr, "finished search at %s\n",
255                                         sha1_to_hex(c->object.sha1));
256                         break;
257                 }
258                 while (parents) {
259                         struct commit *p = parents->item;
260                         parse_commit(p);
261                         if (!(p->object.flags & SEEN))
262                                 insert_by_date(p, &list);
263                         p->object.flags |= c->object.flags;
264                         parents = parents->next;
265                 }
266         }
267
268         if (!match_cnt) {
269                 const unsigned char *sha1 = cmit->object.sha1;
270                 if (always) {
271                         printf("%s", find_unique_abbrev(sha1, abbrev));
272                         if (dirty)
273                                 printf("%s", dirty);
274                         printf("\n");
275                         return;
276                 }
277                 if (unannotated_cnt)
278                         die("No annotated tags can describe '%s'.\n"
279                             "However, there were unannotated tags: try --tags.",
280                             sha1_to_hex(sha1));
281                 else
282                         die("No tags can describe '%s'.\n"
283                             "Try --always, or create some tags.",
284                             sha1_to_hex(sha1));
285         }
286
287         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
288
289         if (gave_up_on) {
290                 insert_by_date(gave_up_on, &list);
291                 seen_commits--;
292         }
293         seen_commits += finish_depth_computation(&list, &all_matches[0]);
294         free_commit_list(list);
295
296         if (debug) {
297                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
298                         struct possible_tag *t = &all_matches[cur_match];
299                         fprintf(stderr, " %-11s %8d %s\n",
300                                 prio_names[t->name->prio],
301                                 t->depth, t->name->path);
302                 }
303                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
304                 if (gave_up_on) {
305                         fprintf(stderr,
306                                 "more than %i tags found; listed %i most recent\n"
307                                 "gave up search at %s\n",
308                                 max_candidates, max_candidates,
309                                 sha1_to_hex(gave_up_on->object.sha1));
310                 }
311         }
312
313         display_name(all_matches[0].name);
314         if (abbrev)
315                 show_suffix(all_matches[0].depth, cmit->object.sha1);
316         if (dirty)
317                 printf("%s", dirty);
318         printf("\n");
319
320         if (!last_one)
321                 clear_commit_marks(cmit, -1);
322 }
323
324 int cmd_describe(int argc, const char **argv, const char *prefix)
325 {
326         int contains = 0;
327         struct option options[] = {
328                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
329                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
330                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
331                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
332                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
333                 OPT__ABBREV(&abbrev),
334                 OPT_SET_INT(0, "exact-match", &max_candidates,
335                             "only output exact matches", 0),
336                 OPT_INTEGER(0, "candidates", &max_candidates,
337                             "consider <n> most recent tags (default: 10)"),
338                 OPT_STRING(0, "match",       &pattern, "pattern",
339                            "only consider tags matching <pattern>"),
340                 OPT_BOOLEAN(0, "always",     &always,
341                            "show abbreviated commit object as fallback"),
342                 {OPTION_STRING, 0, "dirty",  &dirty, "mark",
343                            "append <mark> on dirty working tree (default: \"-dirty\")",
344                  PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
345                 OPT_END(),
346         };
347
348         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
349         if (max_candidates < 0)
350                 max_candidates = 0;
351         else if (max_candidates > MAX_TAGS)
352                 max_candidates = MAX_TAGS;
353
354         save_commit_buffer = 0;
355
356         if (longformat && abbrev == 0)
357                 die("--long is incompatible with --abbrev=0");
358
359         if (contains) {
360                 const char **args = xmalloc((7 + argc) * sizeof(char *));
361                 int i = 0;
362                 args[i++] = "name-rev";
363                 args[i++] = "--name-only";
364                 args[i++] = "--no-undefined";
365                 if (always)
366                         args[i++] = "--always";
367                 if (!all) {
368                         args[i++] = "--tags";
369                         if (pattern) {
370                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
371                                 sprintf(s, "--refs=refs/tags/%s", pattern);
372                                 args[i++] = s;
373                         }
374                 }
375                 memcpy(args + i, argv, argc * sizeof(char *));
376                 args[i + argc] = NULL;
377                 return cmd_name_rev(i + argc, args, prefix);
378         }
379
380         for_each_ref(get_name, NULL);
381         if (!found_names && !always)
382                 die("No names found, cannot describe anything.");
383
384         if (argc == 0) {
385                 if (dirty && !cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1, diff_index_args, prefix))
386                         dirty = NULL;
387                 describe("HEAD", 1);
388         } else if (dirty) {
389                 die("--dirty is incompatible with committishes");
390         } else {
391                 while (argc-- > 0) {
392                         describe(*argv++, argc == 0);
393                 }
394         }
395         return 0;
396 }