git-describe: Die early if there are no possible descriptions
[git/jnareb-git.git] / builtin-rev-list.c
blob4ba1c12e0b6fedb056aebed6ffc8f8bb8d6cfd18
1 #include "cache.h"
2 #include "commit.h"
3 #include "diff.h"
4 #include "revision.h"
5 #include "list-objects.h"
6 #include "builtin.h"
7 #include "log-tree.h"
8 #include "graph.h"
9 #include "bisect.h"
11 static const char rev_list_usage[] =
12 "git rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
13 " limiting output:\n"
14 " --max-count=nr\n"
15 " --max-age=epoch\n"
16 " --min-age=epoch\n"
17 " --sparse\n"
18 " --no-merges\n"
19 " --remove-empty\n"
20 " --all\n"
21 " --branches\n"
22 " --tags\n"
23 " --remotes\n"
24 " --stdin\n"
25 " --quiet\n"
26 " ordering output:\n"
27 " --topo-order\n"
28 " --date-order\n"
29 " --reverse\n"
30 " formatting output:\n"
31 " --parents\n"
32 " --children\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\n"
42 " --bisect-all"
45 static void finish_commit(struct commit *commit, void *data);
46 static void show_commit(struct commit *commit, void *data)
48 struct rev_list_info *info = data;
49 struct rev_info *revs = info->revs;
51 graph_show_commit(revs->graph);
53 if (info->show_timestamp)
54 printf("%lu ", commit->date);
55 if (info->header_prefix)
56 fputs(info->header_prefix, stdout);
58 if (!revs->graph) {
59 if (commit->object.flags & BOUNDARY)
60 putchar('-');
61 else if (commit->object.flags & UNINTERESTING)
62 putchar('^');
63 else if (revs->left_right) {
64 if (commit->object.flags & SYMMETRIC_LEFT)
65 putchar('<');
66 else
67 putchar('>');
70 if (revs->abbrev_commit && revs->abbrev)
71 fputs(find_unique_abbrev(commit->object.sha1, revs->abbrev),
72 stdout);
73 else
74 fputs(sha1_to_hex(commit->object.sha1), stdout);
75 if (revs->print_parents) {
76 struct commit_list *parents = commit->parents;
77 while (parents) {
78 printf(" %s", sha1_to_hex(parents->item->object.sha1));
79 parents = parents->next;
82 if (revs->children.name) {
83 struct commit_list *children;
85 children = lookup_decoration(&revs->children, &commit->object);
86 while (children) {
87 printf(" %s", sha1_to_hex(children->item->object.sha1));
88 children = children->next;
91 show_decorations(revs, commit);
92 if (revs->commit_format == CMIT_FMT_ONELINE)
93 putchar(' ');
94 else
95 putchar('\n');
97 if (revs->verbose_header && commit->buffer) {
98 struct strbuf buf = STRBUF_INIT;
99 pretty_print_commit(revs->commit_format, commit,
100 &buf, revs->abbrev, NULL, NULL,
101 revs->date_mode, 0);
102 if (revs->graph) {
103 if (buf.len) {
104 if (revs->commit_format != CMIT_FMT_ONELINE)
105 graph_show_oneline(revs->graph);
107 graph_show_commit_msg(revs->graph, &buf);
110 * Add a newline after the commit message.
112 * Usually, this newline produces a blank
113 * padding line between entries, in which case
114 * we need to add graph padding on this line.
116 * However, the commit message may not end in a
117 * newline. In this case the newline simply
118 * ends the last line of the commit message,
119 * and we don't need any graph output. (This
120 * always happens with CMIT_FMT_ONELINE, and it
121 * happens with CMIT_FMT_USERFORMAT when the
122 * format doesn't explicitly end in a newline.)
124 if (buf.len && buf.buf[buf.len - 1] == '\n')
125 graph_show_padding(revs->graph);
126 putchar('\n');
127 } else {
129 * If the message buffer is empty, just show
130 * the rest of the graph output for this
131 * commit.
133 if (graph_show_remainder(revs->graph))
134 putchar('\n');
136 } else {
137 if (buf.len)
138 printf("%s%c", buf.buf, info->hdr_termination);
140 strbuf_release(&buf);
141 } else {
142 if (graph_show_remainder(revs->graph))
143 putchar('\n');
145 maybe_flush_or_die(stdout, "stdout");
146 finish_commit(commit, data);
149 static void finish_commit(struct commit *commit, void *data)
151 if (commit->parents) {
152 free_commit_list(commit->parents);
153 commit->parents = NULL;
155 free(commit->buffer);
156 commit->buffer = NULL;
159 static void finish_object(struct object *obj, const struct name_path *path, const char *name)
161 if (obj->type == OBJ_BLOB && !has_sha1_file(obj->sha1))
162 die("missing blob object '%s'", sha1_to_hex(obj->sha1));
165 static void show_object(struct object *obj, const struct name_path *path, const char *component)
167 char *name = path_name(path, component);
168 /* An object with name "foo\n0000000..." can be used to
169 * confuse downstream "git pack-objects" very badly.
171 const char *ep = strchr(name, '\n');
173 finish_object(obj, path, name);
174 if (ep) {
175 printf("%s %.*s\n", sha1_to_hex(obj->sha1),
176 (int) (ep - name),
177 name);
179 else
180 printf("%s %s\n", sha1_to_hex(obj->sha1), name);
181 free(name);
184 static void show_edge(struct commit *commit)
186 printf("-%s\n", sha1_to_hex(commit->object.sha1));
189 static inline int log2i(int n)
191 int log2 = 0;
193 for (; n > 1; n >>= 1)
194 log2++;
196 return log2;
199 static inline int exp2i(int n)
201 return 1 << n;
205 * Estimate the number of bisect steps left (after the current step)
207 * For any x between 0 included and 2^n excluded, the probability for
208 * n - 1 steps left looks like:
210 * P(2^n + x) == (2^n - x) / (2^n + x)
212 * and P(2^n + x) < 0.5 means 2^n < 3x
214 int estimate_bisect_steps(int all)
216 int n, x, e;
218 if (all < 3)
219 return 0;
221 n = log2i(all);
222 e = exp2i(n);
223 x = all - e;
225 return (e < 3 * x) ? n : n - 1;
228 void print_commit_list(struct commit_list *list,
229 const char *format_cur,
230 const char *format_last)
232 for ( ; list; list = list->next) {
233 const char *format = list->next ? format_cur : format_last;
234 printf(format, sha1_to_hex(list->item->object.sha1));
238 static void show_tried_revs(struct commit_list *tried)
240 printf("bisect_tried='");
241 print_commit_list(tried, "%s|", "%s");
242 printf("'\n");
245 static void print_var_str(const char *var, const char *val)
247 printf("%s='%s'\n", var, val);
250 static void print_var_int(const char *var, int val)
252 printf("%s=%d\n", var, val);
255 int show_bisect_vars(struct rev_list_info *info, int reaches, int all)
257 int cnt, flags = info->bisect_show_flags;
258 char hex[41] = "";
259 struct commit_list *tried;
260 struct rev_info *revs = info->revs;
262 if (!revs->commits && !(flags & BISECT_SHOW_TRIED))
263 return 1;
265 revs->commits = filter_skipped(revs->commits, &tried,
266 flags & BISECT_SHOW_ALL,
267 NULL, NULL);
270 * revs->commits can reach "reaches" commits among
271 * "all" commits. If it is good, then there are
272 * (all-reaches) commits left to be bisected.
273 * On the other hand, if it is bad, then the set
274 * to bisect is "reaches".
275 * A bisect set of size N has (N-1) commits further
276 * to test, as we already know one bad one.
278 cnt = all - reaches;
279 if (cnt < reaches)
280 cnt = reaches;
282 if (revs->commits)
283 strcpy(hex, sha1_to_hex(revs->commits->item->object.sha1));
285 if (flags & BISECT_SHOW_ALL) {
286 traverse_commit_list(revs, show_commit, show_object, info);
287 printf("------\n");
290 if (flags & BISECT_SHOW_TRIED)
291 show_tried_revs(tried);
293 print_var_str("bisect_rev", hex);
294 print_var_int("bisect_nr", cnt - 1);
295 print_var_int("bisect_good", all - reaches - 1);
296 print_var_int("bisect_bad", reaches - 1);
297 print_var_int("bisect_all", all);
298 print_var_int("bisect_steps", estimate_bisect_steps(all));
300 return 0;
303 int cmd_rev_list(int argc, const char **argv, const char *prefix)
305 struct rev_info revs;
306 struct rev_list_info info;
307 int i;
308 int read_from_stdin = 0;
309 int bisect_list = 0;
310 int bisect_show_vars = 0;
311 int bisect_find_all = 0;
312 int quiet = 0;
314 git_config(git_default_config, NULL);
315 init_revisions(&revs, prefix);
316 revs.abbrev = 0;
317 revs.commit_format = CMIT_FMT_UNSPECIFIED;
318 argc = setup_revisions(argc, argv, &revs, NULL);
320 memset(&info, 0, sizeof(info));
321 info.revs = &revs;
323 quiet = DIFF_OPT_TST(&revs.diffopt, QUIET);
324 for (i = 1 ; i < argc; i++) {
325 const char *arg = argv[i];
327 if (!strcmp(arg, "--header")) {
328 revs.verbose_header = 1;
329 continue;
331 if (!strcmp(arg, "--timestamp")) {
332 info.show_timestamp = 1;
333 continue;
335 if (!strcmp(arg, "--bisect")) {
336 bisect_list = 1;
337 continue;
339 if (!strcmp(arg, "--bisect-all")) {
340 bisect_list = 1;
341 bisect_find_all = 1;
342 info.bisect_show_flags = BISECT_SHOW_ALL;
343 revs.show_decorations = 1;
344 continue;
346 if (!strcmp(arg, "--bisect-vars")) {
347 bisect_list = 1;
348 bisect_show_vars = 1;
349 continue;
351 if (!strcmp(arg, "--stdin")) {
352 if (read_from_stdin++)
353 die("--stdin given twice?");
354 read_revisions_from_stdin(&revs);
355 continue;
357 usage(rev_list_usage);
360 if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
361 /* The command line has a --pretty */
362 info.hdr_termination = '\n';
363 if (revs.commit_format == CMIT_FMT_ONELINE)
364 info.header_prefix = "";
365 else
366 info.header_prefix = "commit ";
368 else if (revs.verbose_header)
369 /* Only --header was specified */
370 revs.commit_format = CMIT_FMT_RAW;
372 if ((!revs.commits &&
373 (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
374 !revs.pending.nr)) ||
375 revs.diff)
376 usage(rev_list_usage);
378 save_commit_buffer = revs.verbose_header ||
379 revs.grep_filter.pattern_list;
380 if (bisect_list)
381 revs.limited = 1;
383 if (prepare_revision_walk(&revs))
384 die("revision walk setup failed");
385 if (revs.tree_objects)
386 mark_edges_uninteresting(revs.commits, &revs, show_edge);
388 if (bisect_list) {
389 int reaches = reaches, all = all;
391 revs.commits = find_bisection(revs.commits, &reaches, &all,
392 bisect_find_all);
394 if (bisect_show_vars)
395 return show_bisect_vars(&info, reaches, all);
398 traverse_commit_list(&revs,
399 quiet ? finish_commit : show_commit,
400 quiet ? finish_object : show_object,
401 &info);
403 return 0;