cherry-pick: fix docs describing handling of empty commits
[git/gitweb.git] / builtin / rev-parse.c
blob1a6122d3ae29609c30c26959fbb1ff799e13a4b2
1 /*
2 * rev-parse.c
4 * Copyright (C) Linus Torvalds, 2005
5 */
6 #include "cache.h"
7 #include "commit.h"
8 #include "refs.h"
9 #include "quote.h"
10 #include "builtin.h"
11 #include "parse-options.h"
12 #include "diff.h"
13 #include "revision.h"
15 #define DO_REVS 1
16 #define DO_NOREV 2
17 #define DO_FLAGS 4
18 #define DO_NONFLAGS 8
19 static int filter = ~0;
21 static const char *def;
23 #define NORMAL 0
24 #define REVERSED 1
25 static int show_type = NORMAL;
27 #define SHOW_SYMBOLIC_ASIS 1
28 #define SHOW_SYMBOLIC_FULL 2
29 static int symbolic;
30 static int abbrev;
31 static int abbrev_ref;
32 static int abbrev_ref_strict;
33 static int output_sq;
35 static int stuck_long;
36 static struct string_list *ref_excludes;
39 * Some arguments are relevant "revision" arguments,
40 * others are about output format or other details.
41 * This sorts it all out.
43 static int is_rev_argument(const char *arg)
45 static const char *rev_args[] = {
46 "--all",
47 "--bisect",
48 "--dense",
49 "--branches=",
50 "--branches",
51 "--header",
52 "--ignore-missing",
53 "--max-age=",
54 "--max-count=",
55 "--min-age=",
56 "--no-merges",
57 "--min-parents=",
58 "--no-min-parents",
59 "--max-parents=",
60 "--no-max-parents",
61 "--objects",
62 "--objects-edge",
63 "--parents",
64 "--pretty",
65 "--remotes=",
66 "--remotes",
67 "--glob=",
68 "--sparse",
69 "--tags=",
70 "--tags",
71 "--topo-order",
72 "--date-order",
73 "--unpacked",
74 NULL
76 const char **p = rev_args;
78 /* accept -<digit>, like traditional "head" */
79 if ((*arg == '-') && isdigit(arg[1]))
80 return 1;
82 for (;;) {
83 const char *str = *p++;
84 int len;
85 if (!str)
86 return 0;
87 len = strlen(str);
88 if (!strcmp(arg, str) ||
89 (str[len-1] == '=' && !strncmp(arg, str, len)))
90 return 1;
94 /* Output argument as a string, either SQ or normal */
95 static void show(const char *arg)
97 if (output_sq) {
98 int sq = '\'', ch;
100 putchar(sq);
101 while ((ch = *arg++)) {
102 if (ch == sq)
103 fputs("'\\'", stdout);
104 putchar(ch);
106 putchar(sq);
107 putchar(' ');
109 else
110 puts(arg);
113 /* Like show(), but with a negation prefix according to type */
114 static void show_with_type(int type, const char *arg)
116 if (type != show_type)
117 putchar('^');
118 show(arg);
121 /* Output a revision, only if filter allows it */
122 static void show_rev(int type, const unsigned char *sha1, const char *name)
124 if (!(filter & DO_REVS))
125 return;
126 def = NULL;
128 if ((symbolic || abbrev_ref) && name) {
129 if (symbolic == SHOW_SYMBOLIC_FULL || abbrev_ref) {
130 unsigned char discard[20];
131 char *full;
133 switch (dwim_ref(name, strlen(name), discard, &full)) {
134 case 0:
136 * Not found -- not a ref. We could
137 * emit "name" here, but symbolic-full
138 * users are interested in finding the
139 * refs spelled in full, and they would
140 * need to filter non-refs if we did so.
142 break;
143 case 1: /* happy */
144 if (abbrev_ref)
145 full = shorten_unambiguous_ref(full,
146 abbrev_ref_strict);
147 show_with_type(type, full);
148 break;
149 default: /* ambiguous */
150 error("refname '%s' is ambiguous", name);
151 break;
153 } else {
154 show_with_type(type, name);
157 else if (abbrev)
158 show_with_type(type, find_unique_abbrev(sha1, abbrev));
159 else
160 show_with_type(type, sha1_to_hex(sha1));
163 /* Output a flag, only if filter allows it. */
164 static int show_flag(const char *arg)
166 if (!(filter & DO_FLAGS))
167 return 0;
168 if (filter & (is_rev_argument(arg) ? DO_REVS : DO_NOREV)) {
169 show(arg);
170 return 1;
172 return 0;
175 static int show_default(void)
177 const char *s = def;
179 if (s) {
180 unsigned char sha1[20];
182 def = NULL;
183 if (!get_sha1(s, sha1)) {
184 show_rev(NORMAL, sha1, s);
185 return 1;
188 return 0;
191 static int show_reference(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
193 if (ref_excluded(ref_excludes, refname))
194 return 0;
195 show_rev(NORMAL, sha1, refname);
196 return 0;
199 static int anti_reference(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
201 show_rev(REVERSED, sha1, refname);
202 return 0;
205 static int show_abbrev(const unsigned char *sha1, void *cb_data)
207 show_rev(NORMAL, sha1, NULL);
208 return 0;
211 static void show_datestring(const char *flag, const char *datestr)
213 static char buffer[100];
215 /* date handling requires both flags and revs */
216 if ((filter & (DO_FLAGS | DO_REVS)) != (DO_FLAGS | DO_REVS))
217 return;
218 snprintf(buffer, sizeof(buffer), "%s%lu", flag, approxidate(datestr));
219 show(buffer);
222 static int show_file(const char *arg, int output_prefix)
224 show_default();
225 if ((filter & (DO_NONFLAGS|DO_NOREV)) == (DO_NONFLAGS|DO_NOREV)) {
226 if (output_prefix) {
227 const char *prefix = startup_info->prefix;
228 show(prefix_filename(prefix,
229 prefix ? strlen(prefix) : 0,
230 arg));
231 } else
232 show(arg);
233 return 1;
235 return 0;
238 static int try_difference(const char *arg)
240 char *dotdot;
241 unsigned char sha1[20];
242 unsigned char end[20];
243 const char *next;
244 const char *this;
245 int symmetric;
246 static const char head_by_default[] = "HEAD";
248 if (!(dotdot = strstr(arg, "..")))
249 return 0;
250 next = dotdot + 2;
251 this = arg;
252 symmetric = (*next == '.');
254 *dotdot = 0;
255 next += symmetric;
257 if (!*next)
258 next = head_by_default;
259 if (dotdot == arg)
260 this = head_by_default;
262 if (this == head_by_default && next == head_by_default &&
263 !symmetric) {
265 * Just ".."? That is not a range but the
266 * pathspec for the parent directory.
268 *dotdot = '.';
269 return 0;
272 if (!get_sha1_committish(this, sha1) && !get_sha1_committish(next, end)) {
273 show_rev(NORMAL, end, next);
274 show_rev(symmetric ? NORMAL : REVERSED, sha1, this);
275 if (symmetric) {
276 struct commit_list *exclude;
277 struct commit *a, *b;
278 a = lookup_commit_reference(sha1);
279 b = lookup_commit_reference(end);
280 exclude = get_merge_bases(a, b, 1);
281 while (exclude) {
282 struct commit_list *n = exclude->next;
283 show_rev(REVERSED,
284 exclude->item->object.sha1,NULL);
285 free(exclude);
286 exclude = n;
289 *dotdot = '.';
290 return 1;
292 *dotdot = '.';
293 return 0;
296 static int try_parent_shorthands(const char *arg)
298 char *dotdot;
299 unsigned char sha1[20];
300 struct commit *commit;
301 struct commit_list *parents;
302 int parents_only;
304 if ((dotdot = strstr(arg, "^!")))
305 parents_only = 0;
306 else if ((dotdot = strstr(arg, "^@")))
307 parents_only = 1;
309 if (!dotdot || dotdot[2])
310 return 0;
312 *dotdot = 0;
313 if (get_sha1_committish(arg, sha1)) {
314 *dotdot = '^';
315 return 0;
318 if (!parents_only)
319 show_rev(NORMAL, sha1, arg);
320 commit = lookup_commit_reference(sha1);
321 for (parents = commit->parents; parents; parents = parents->next)
322 show_rev(parents_only ? NORMAL : REVERSED,
323 parents->item->object.sha1, arg);
325 *dotdot = '^';
326 return 1;
329 static int parseopt_dump(const struct option *o, const char *arg, int unset)
331 struct strbuf *parsed = o->value;
332 if (unset)
333 strbuf_addf(parsed, " --no-%s", o->long_name);
334 else if (o->short_name && (o->long_name == NULL || !stuck_long))
335 strbuf_addf(parsed, " -%c", o->short_name);
336 else
337 strbuf_addf(parsed, " --%s", o->long_name);
338 if (arg) {
339 if (!stuck_long)
340 strbuf_addch(parsed, ' ');
341 else if (o->long_name)
342 strbuf_addch(parsed, '=');
343 sq_quote_buf(parsed, arg);
345 return 0;
348 static const char *skipspaces(const char *s)
350 while (isspace(*s))
351 s++;
352 return s;
355 static int cmd_parseopt(int argc, const char **argv, const char *prefix)
357 static int keep_dashdash = 0, stop_at_non_option = 0;
358 static char const * const parseopt_usage[] = {
359 N_("git rev-parse --parseopt [options] -- [<args>...]"),
360 NULL
362 static struct option parseopt_opts[] = {
363 OPT_BOOL(0, "keep-dashdash", &keep_dashdash,
364 N_("keep the `--` passed as an arg")),
365 OPT_BOOL(0, "stop-at-non-option", &stop_at_non_option,
366 N_("stop parsing after the "
367 "first non-option argument")),
368 OPT_BOOL(0, "stuck-long", &stuck_long,
369 N_("output in stuck long form")),
370 OPT_END(),
373 struct strbuf sb = STRBUF_INIT, parsed = STRBUF_INIT;
374 const char **usage = NULL;
375 struct option *opts = NULL;
376 int onb = 0, osz = 0, unb = 0, usz = 0;
378 strbuf_addstr(&parsed, "set --");
379 argc = parse_options(argc, argv, prefix, parseopt_opts, parseopt_usage,
380 PARSE_OPT_KEEP_DASHDASH);
381 if (argc < 1 || strcmp(argv[0], "--"))
382 usage_with_options(parseopt_usage, parseopt_opts);
384 /* get the usage up to the first line with a -- on it */
385 for (;;) {
386 if (strbuf_getline(&sb, stdin, '\n') == EOF)
387 die("premature end of input");
388 ALLOC_GROW(usage, unb + 1, usz);
389 if (!strcmp("--", sb.buf)) {
390 if (unb < 1)
391 die("no usage string given before the `--' separator");
392 usage[unb] = NULL;
393 break;
395 usage[unb++] = strbuf_detach(&sb, NULL);
398 /* parse: (<short>|<short>,<long>|<long>)[*=?!]*<arghint>? SP+ <help> */
399 while (strbuf_getline(&sb, stdin, '\n') != EOF) {
400 const char *s;
401 const char *end;
402 struct option *o;
404 if (!sb.len)
405 continue;
407 ALLOC_GROW(opts, onb + 1, osz);
408 memset(opts + onb, 0, sizeof(opts[onb]));
410 o = &opts[onb++];
411 s = strchr(sb.buf, ' ');
412 if (!s || *sb.buf == ' ') {
413 o->type = OPTION_GROUP;
414 o->help = xstrdup(skipspaces(sb.buf));
415 continue;
418 o->type = OPTION_CALLBACK;
419 o->help = xstrdup(skipspaces(s));
420 o->value = &parsed;
421 o->flags = PARSE_OPT_NOARG;
422 o->callback = &parseopt_dump;
424 /* Possible argument name hint */
425 end = s;
426 while (s > sb.buf && strchr("*=?!", s[-1]) == NULL)
427 --s;
428 if (s != sb.buf && s != end)
429 o->argh = xmemdupz(s, end - s);
430 if (s == sb.buf)
431 s = end;
433 while (s > sb.buf && strchr("*=?!", s[-1])) {
434 switch (*--s) {
435 case '=':
436 o->flags &= ~PARSE_OPT_NOARG;
437 break;
438 case '?':
439 o->flags &= ~PARSE_OPT_NOARG;
440 o->flags |= PARSE_OPT_OPTARG;
441 break;
442 case '!':
443 o->flags |= PARSE_OPT_NONEG;
444 break;
445 case '*':
446 o->flags |= PARSE_OPT_HIDDEN;
447 break;
451 if (s - sb.buf == 1) /* short option only */
452 o->short_name = *sb.buf;
453 else if (sb.buf[1] != ',') /* long option only */
454 o->long_name = xmemdupz(sb.buf, s - sb.buf);
455 else {
456 o->short_name = *sb.buf;
457 o->long_name = xmemdupz(sb.buf + 2, s - sb.buf - 2);
460 strbuf_release(&sb);
462 /* put an OPT_END() */
463 ALLOC_GROW(opts, onb + 1, osz);
464 memset(opts + onb, 0, sizeof(opts[onb]));
465 argc = parse_options(argc, argv, prefix, opts, usage,
466 (keep_dashdash ? PARSE_OPT_KEEP_DASHDASH : 0) |
467 (stop_at_non_option ? PARSE_OPT_STOP_AT_NON_OPTION : 0) |
468 PARSE_OPT_SHELL_EVAL);
470 strbuf_addf(&parsed, " --");
471 sq_quote_argv(&parsed, argv, 0);
472 puts(parsed.buf);
473 return 0;
476 static int cmd_sq_quote(int argc, const char **argv)
478 struct strbuf buf = STRBUF_INIT;
480 if (argc)
481 sq_quote_argv(&buf, argv, 0);
482 printf("%s\n", buf.buf);
483 strbuf_release(&buf);
485 return 0;
488 static void die_no_single_rev(int quiet)
490 if (quiet)
491 exit(1);
492 else
493 die("Needed a single revision");
496 static const char builtin_rev_parse_usage[] =
497 N_("git rev-parse --parseopt [options] -- [<args>...]\n"
498 " or: git rev-parse --sq-quote [<arg>...]\n"
499 " or: git rev-parse [options] [<arg>...]\n"
500 "\n"
501 "Run \"git rev-parse --parseopt -h\" for more information on the first usage.");
503 int cmd_rev_parse(int argc, const char **argv, const char *prefix)
505 int i, as_is = 0, verify = 0, quiet = 0, revs_count = 0, type = 0;
506 int has_dashdash = 0;
507 int output_prefix = 0;
508 unsigned char sha1[20];
509 const char *name = NULL;
511 if (argc > 1 && !strcmp("--parseopt", argv[1]))
512 return cmd_parseopt(argc - 1, argv + 1, prefix);
514 if (argc > 1 && !strcmp("--sq-quote", argv[1]))
515 return cmd_sq_quote(argc - 2, argv + 2);
517 if (argc > 1 && !strcmp("-h", argv[1]))
518 usage(builtin_rev_parse_usage);
520 for (i = 1; i < argc; i++) {
521 if (!strcmp(argv[i], "--")) {
522 has_dashdash = 1;
523 break;
527 prefix = setup_git_directory();
528 git_config(git_default_config, NULL);
529 for (i = 1; i < argc; i++) {
530 const char *arg = argv[i];
532 if (as_is) {
533 if (show_file(arg, output_prefix) && as_is < 2)
534 verify_filename(prefix, arg, 0);
535 continue;
537 if (!strcmp(arg,"-n")) {
538 if (++i >= argc)
539 die("-n requires an argument");
540 if ((filter & DO_FLAGS) && (filter & DO_REVS)) {
541 show(arg);
542 show(argv[i]);
544 continue;
546 if (starts_with(arg, "-n")) {
547 if ((filter & DO_FLAGS) && (filter & DO_REVS))
548 show(arg);
549 continue;
552 if (*arg == '-') {
553 if (!strcmp(arg, "--")) {
554 as_is = 2;
555 /* Pass on the "--" if we show anything but files.. */
556 if (filter & (DO_FLAGS | DO_REVS))
557 show_file(arg, 0);
558 continue;
560 if (!strcmp(arg, "--default")) {
561 def = argv[++i];
562 if (!def)
563 die("--default requires an argument");
564 continue;
566 if (!strcmp(arg, "--prefix")) {
567 prefix = argv[++i];
568 if (!prefix)
569 die("--prefix requires an argument");
570 startup_info->prefix = prefix;
571 output_prefix = 1;
572 continue;
574 if (!strcmp(arg, "--revs-only")) {
575 filter &= ~DO_NOREV;
576 continue;
578 if (!strcmp(arg, "--no-revs")) {
579 filter &= ~DO_REVS;
580 continue;
582 if (!strcmp(arg, "--flags")) {
583 filter &= ~DO_NONFLAGS;
584 continue;
586 if (!strcmp(arg, "--no-flags")) {
587 filter &= ~DO_FLAGS;
588 continue;
590 if (!strcmp(arg, "--verify")) {
591 filter &= ~(DO_FLAGS|DO_NOREV);
592 verify = 1;
593 continue;
595 if (!strcmp(arg, "--quiet") || !strcmp(arg, "-q")) {
596 quiet = 1;
597 continue;
599 if (!strcmp(arg, "--short") ||
600 starts_with(arg, "--short=")) {
601 filter &= ~(DO_FLAGS|DO_NOREV);
602 verify = 1;
603 abbrev = DEFAULT_ABBREV;
604 if (arg[7] == '=')
605 abbrev = strtoul(arg + 8, NULL, 10);
606 if (abbrev < MINIMUM_ABBREV)
607 abbrev = MINIMUM_ABBREV;
608 else if (40 <= abbrev)
609 abbrev = 40;
610 continue;
612 if (!strcmp(arg, "--sq")) {
613 output_sq = 1;
614 continue;
616 if (!strcmp(arg, "--not")) {
617 show_type ^= REVERSED;
618 continue;
620 if (!strcmp(arg, "--symbolic")) {
621 symbolic = SHOW_SYMBOLIC_ASIS;
622 continue;
624 if (!strcmp(arg, "--symbolic-full-name")) {
625 symbolic = SHOW_SYMBOLIC_FULL;
626 continue;
628 if (starts_with(arg, "--abbrev-ref") &&
629 (!arg[12] || arg[12] == '=')) {
630 abbrev_ref = 1;
631 abbrev_ref_strict = warn_ambiguous_refs;
632 if (arg[12] == '=') {
633 if (!strcmp(arg + 13, "strict"))
634 abbrev_ref_strict = 1;
635 else if (!strcmp(arg + 13, "loose"))
636 abbrev_ref_strict = 0;
637 else
638 die("unknown mode for %s", arg);
640 continue;
642 if (!strcmp(arg, "--all")) {
643 for_each_ref(show_reference, NULL);
644 continue;
646 if (starts_with(arg, "--disambiguate=")) {
647 for_each_abbrev(arg + 15, show_abbrev, NULL);
648 continue;
650 if (!strcmp(arg, "--bisect")) {
651 for_each_ref_in("refs/bisect/bad", show_reference, NULL);
652 for_each_ref_in("refs/bisect/good", anti_reference, NULL);
653 continue;
655 if (starts_with(arg, "--branches=")) {
656 for_each_glob_ref_in(show_reference, arg + 11,
657 "refs/heads/", NULL);
658 clear_ref_exclusion(&ref_excludes);
659 continue;
661 if (!strcmp(arg, "--branches")) {
662 for_each_branch_ref(show_reference, NULL);
663 clear_ref_exclusion(&ref_excludes);
664 continue;
666 if (starts_with(arg, "--tags=")) {
667 for_each_glob_ref_in(show_reference, arg + 7,
668 "refs/tags/", NULL);
669 clear_ref_exclusion(&ref_excludes);
670 continue;
672 if (!strcmp(arg, "--tags")) {
673 for_each_tag_ref(show_reference, NULL);
674 clear_ref_exclusion(&ref_excludes);
675 continue;
677 if (starts_with(arg, "--glob=")) {
678 for_each_glob_ref(show_reference, arg + 7, NULL);
679 clear_ref_exclusion(&ref_excludes);
680 continue;
682 if (starts_with(arg, "--remotes=")) {
683 for_each_glob_ref_in(show_reference, arg + 10,
684 "refs/remotes/", NULL);
685 clear_ref_exclusion(&ref_excludes);
686 continue;
688 if (!strcmp(arg, "--remotes")) {
689 for_each_remote_ref(show_reference, NULL);
690 clear_ref_exclusion(&ref_excludes);
691 continue;
693 if (starts_with(arg, "--exclude=")) {
694 add_ref_exclusion(&ref_excludes, arg + 10);
695 continue;
697 if (!strcmp(arg, "--local-env-vars")) {
698 int i;
699 for (i = 0; local_repo_env[i]; i++)
700 printf("%s\n", local_repo_env[i]);
701 continue;
703 if (!strcmp(arg, "--show-toplevel")) {
704 const char *work_tree = get_git_work_tree();
705 if (work_tree)
706 puts(work_tree);
707 continue;
709 if (!strcmp(arg, "--show-prefix")) {
710 if (prefix)
711 puts(prefix);
712 else
713 putchar('\n');
714 continue;
716 if (!strcmp(arg, "--show-cdup")) {
717 const char *pfx = prefix;
718 if (!is_inside_work_tree()) {
719 const char *work_tree =
720 get_git_work_tree();
721 if (work_tree)
722 printf("%s\n", work_tree);
723 continue;
725 while (pfx) {
726 pfx = strchr(pfx, '/');
727 if (pfx) {
728 pfx++;
729 printf("../");
732 putchar('\n');
733 continue;
735 if (!strcmp(arg, "--git-dir")) {
736 const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
737 static char cwd[PATH_MAX];
738 int len;
739 if (gitdir) {
740 puts(gitdir);
741 continue;
743 if (!prefix) {
744 puts(".git");
745 continue;
747 if (!getcwd(cwd, PATH_MAX))
748 die_errno("unable to get current working directory");
749 len = strlen(cwd);
750 printf("%s%s.git\n", cwd, len && cwd[len-1] != '/' ? "/" : "");
751 continue;
753 if (!strcmp(arg, "--resolve-git-dir")) {
754 const char *gitdir = argv[++i];
755 if (!gitdir)
756 die("--resolve-git-dir requires an argument");
757 gitdir = resolve_gitdir(gitdir);
758 if (!gitdir)
759 die("not a gitdir '%s'", argv[i]);
760 puts(gitdir);
761 continue;
763 if (!strcmp(arg, "--is-inside-git-dir")) {
764 printf("%s\n", is_inside_git_dir() ? "true"
765 : "false");
766 continue;
768 if (!strcmp(arg, "--is-inside-work-tree")) {
769 printf("%s\n", is_inside_work_tree() ? "true"
770 : "false");
771 continue;
773 if (!strcmp(arg, "--is-bare-repository")) {
774 printf("%s\n", is_bare_repository() ? "true"
775 : "false");
776 continue;
778 if (starts_with(arg, "--since=")) {
779 show_datestring("--max-age=", arg+8);
780 continue;
782 if (starts_with(arg, "--after=")) {
783 show_datestring("--max-age=", arg+8);
784 continue;
786 if (starts_with(arg, "--before=")) {
787 show_datestring("--min-age=", arg+9);
788 continue;
790 if (starts_with(arg, "--until=")) {
791 show_datestring("--min-age=", arg+8);
792 continue;
794 if (show_flag(arg) && verify)
795 die_no_single_rev(quiet);
796 continue;
799 /* Not a flag argument */
800 if (try_difference(arg))
801 continue;
802 if (try_parent_shorthands(arg))
803 continue;
804 name = arg;
805 type = NORMAL;
806 if (*arg == '^') {
807 name++;
808 type = REVERSED;
810 if (!get_sha1(name, sha1)) {
811 if (verify)
812 revs_count++;
813 else
814 show_rev(type, sha1, name);
815 continue;
817 if (verify)
818 die_no_single_rev(quiet);
819 if (has_dashdash)
820 die("bad revision '%s'", arg);
821 as_is = 1;
822 if (!show_file(arg, output_prefix))
823 continue;
824 verify_filename(prefix, arg, 1);
826 if (verify) {
827 if (revs_count == 1) {
828 show_rev(type, sha1, name);
829 return 0;
830 } else if (revs_count == 0 && show_default())
831 return 0;
832 die_no_single_rev(quiet);
833 } else
834 show_default();
835 return 0;