Documentation: merge: add a section about fast-forward
[git/gsoc2010-gitweb.git] / builtin-rev-parse.c
blob37d02335212dea9672e2472970f66dc4ac95dfd1
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"
13 #define DO_REVS 1
14 #define DO_NOREV 2
15 #define DO_FLAGS 4
16 #define DO_NONFLAGS 8
17 static int filter = ~0;
19 static const char *def;
21 #define NORMAL 0
22 #define REVERSED 1
23 static int show_type = NORMAL;
25 #define SHOW_SYMBOLIC_ASIS 1
26 #define SHOW_SYMBOLIC_FULL 2
27 static int symbolic;
28 static int abbrev;
29 static int abbrev_ref;
30 static int abbrev_ref_strict;
31 static int output_sq;
34 * Some arguments are relevant "revision" arguments,
35 * others are about output format or other details.
36 * This sorts it all out.
38 static int is_rev_argument(const char *arg)
40 static const char *rev_args[] = {
41 "--all",
42 "--bisect",
43 "--dense",
44 "--branches",
45 "--header",
46 "--max-age=",
47 "--max-count=",
48 "--min-age=",
49 "--no-merges",
50 "--objects",
51 "--objects-edge",
52 "--parents",
53 "--pretty",
54 "--remotes",
55 "--sparse",
56 "--tags",
57 "--topo-order",
58 "--date-order",
59 "--unpacked",
60 NULL
62 const char **p = rev_args;
64 /* accept -<digit>, like traditional "head" */
65 if ((*arg == '-') && isdigit(arg[1]))
66 return 1;
68 for (;;) {
69 const char *str = *p++;
70 int len;
71 if (!str)
72 return 0;
73 len = strlen(str);
74 if (!strcmp(arg, str) ||
75 (str[len-1] == '=' && !strncmp(arg, str, len)))
76 return 1;
80 /* Output argument as a string, either SQ or normal */
81 static void show(const char *arg)
83 if (output_sq) {
84 int sq = '\'', ch;
86 putchar(sq);
87 while ((ch = *arg++)) {
88 if (ch == sq)
89 fputs("'\\'", stdout);
90 putchar(ch);
92 putchar(sq);
93 putchar(' ');
95 else
96 puts(arg);
99 /* Like show(), but with a negation prefix according to type */
100 static void show_with_type(int type, const char *arg)
102 if (type != show_type)
103 putchar('^');
104 show(arg);
107 /* Output a revision, only if filter allows it */
108 static void show_rev(int type, const unsigned char *sha1, const char *name)
110 if (!(filter & DO_REVS))
111 return;
112 def = NULL;
114 if ((symbolic || abbrev_ref) && name) {
115 if (symbolic == SHOW_SYMBOLIC_FULL || abbrev_ref) {
116 unsigned char discard[20];
117 char *full;
119 switch (dwim_ref(name, strlen(name), discard, &full)) {
120 case 0:
122 * Not found -- not a ref. We could
123 * emit "name" here, but symbolic-full
124 * users are interested in finding the
125 * refs spelled in full, and they would
126 * need to filter non-refs if we did so.
128 break;
129 case 1: /* happy */
130 if (abbrev_ref)
131 full = shorten_unambiguous_ref(full,
132 abbrev_ref_strict);
133 show_with_type(type, full);
134 break;
135 default: /* ambiguous */
136 error("refname '%s' is ambiguous", name);
137 break;
139 } else {
140 show_with_type(type, name);
143 else if (abbrev)
144 show_with_type(type, find_unique_abbrev(sha1, abbrev));
145 else
146 show_with_type(type, sha1_to_hex(sha1));
149 /* Output a flag, only if filter allows it. */
150 static int show_flag(const char *arg)
152 if (!(filter & DO_FLAGS))
153 return 0;
154 if (filter & (is_rev_argument(arg) ? DO_REVS : DO_NOREV)) {
155 show(arg);
156 return 1;
158 return 0;
161 static int show_default(void)
163 const char *s = def;
165 if (s) {
166 unsigned char sha1[20];
168 def = NULL;
169 if (!get_sha1(s, sha1)) {
170 show_rev(NORMAL, sha1, s);
171 return 1;
174 return 0;
177 static int show_reference(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
179 show_rev(NORMAL, sha1, refname);
180 return 0;
183 static int anti_reference(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
185 show_rev(REVERSED, sha1, refname);
186 return 0;
189 static void show_datestring(const char *flag, const char *datestr)
191 static char buffer[100];
193 /* date handling requires both flags and revs */
194 if ((filter & (DO_FLAGS | DO_REVS)) != (DO_FLAGS | DO_REVS))
195 return;
196 snprintf(buffer, sizeof(buffer), "%s%lu", flag, approxidate(datestr));
197 show(buffer);
200 static int show_file(const char *arg)
202 show_default();
203 if ((filter & (DO_NONFLAGS|DO_NOREV)) == (DO_NONFLAGS|DO_NOREV)) {
204 show(arg);
205 return 1;
207 return 0;
210 static int try_difference(const char *arg)
212 char *dotdot;
213 unsigned char sha1[20];
214 unsigned char end[20];
215 const char *next;
216 const char *this;
217 int symmetric;
219 if (!(dotdot = strstr(arg, "..")))
220 return 0;
221 next = dotdot + 2;
222 this = arg;
223 symmetric = (*next == '.');
225 *dotdot = 0;
226 next += symmetric;
228 if (!*next)
229 next = "HEAD";
230 if (dotdot == arg)
231 this = "HEAD";
232 if (!get_sha1(this, sha1) && !get_sha1(next, end)) {
233 show_rev(NORMAL, end, next);
234 show_rev(symmetric ? NORMAL : REVERSED, sha1, this);
235 if (symmetric) {
236 struct commit_list *exclude;
237 struct commit *a, *b;
238 a = lookup_commit_reference(sha1);
239 b = lookup_commit_reference(end);
240 exclude = get_merge_bases(a, b, 1);
241 while (exclude) {
242 struct commit_list *n = exclude->next;
243 show_rev(REVERSED,
244 exclude->item->object.sha1,NULL);
245 free(exclude);
246 exclude = n;
249 return 1;
251 *dotdot = '.';
252 return 0;
255 static int try_parent_shorthands(const char *arg)
257 char *dotdot;
258 unsigned char sha1[20];
259 struct commit *commit;
260 struct commit_list *parents;
261 int parents_only;
263 if ((dotdot = strstr(arg, "^!")))
264 parents_only = 0;
265 else if ((dotdot = strstr(arg, "^@")))
266 parents_only = 1;
268 if (!dotdot || dotdot[2])
269 return 0;
271 *dotdot = 0;
272 if (get_sha1(arg, sha1))
273 return 0;
275 if (!parents_only)
276 show_rev(NORMAL, sha1, arg);
277 commit = lookup_commit_reference(sha1);
278 for (parents = commit->parents; parents; parents = parents->next)
279 show_rev(parents_only ? NORMAL : REVERSED,
280 parents->item->object.sha1, arg);
282 return 1;
285 static int parseopt_dump(const struct option *o, const char *arg, int unset)
287 struct strbuf *parsed = o->value;
288 if (unset)
289 strbuf_addf(parsed, " --no-%s", o->long_name);
290 else if (o->short_name)
291 strbuf_addf(parsed, " -%c", o->short_name);
292 else
293 strbuf_addf(parsed, " --%s", o->long_name);
294 if (arg) {
295 strbuf_addch(parsed, ' ');
296 sq_quote_buf(parsed, arg);
298 return 0;
301 static const char *skipspaces(const char *s)
303 while (isspace(*s))
304 s++;
305 return s;
308 static int cmd_parseopt(int argc, const char **argv, const char *prefix)
310 static int keep_dashdash = 0, stop_at_non_option = 0;
311 static char const * const parseopt_usage[] = {
312 "git rev-parse --parseopt [options] -- [<args>...]",
313 NULL
315 static struct option parseopt_opts[] = {
316 OPT_BOOLEAN(0, "keep-dashdash", &keep_dashdash,
317 "keep the `--` passed as an arg"),
318 OPT_BOOLEAN(0, "stop-at-non-option", &stop_at_non_option,
319 "stop parsing after the "
320 "first non-option argument"),
321 OPT_END(),
324 struct strbuf sb = STRBUF_INIT, parsed = STRBUF_INIT;
325 const char **usage = NULL;
326 struct option *opts = NULL;
327 int onb = 0, osz = 0, unb = 0, usz = 0;
329 strbuf_addstr(&parsed, "set --");
330 argc = parse_options(argc, argv, prefix, parseopt_opts, parseopt_usage,
331 PARSE_OPT_KEEP_DASHDASH);
332 if (argc < 1 || strcmp(argv[0], "--"))
333 usage_with_options(parseopt_usage, parseopt_opts);
335 /* get the usage up to the first line with a -- on it */
336 for (;;) {
337 if (strbuf_getline(&sb, stdin, '\n') == EOF)
338 die("premature end of input");
339 ALLOC_GROW(usage, unb + 1, usz);
340 if (!strcmp("--", sb.buf)) {
341 if (unb < 1)
342 die("no usage string given before the `--' separator");
343 usage[unb] = NULL;
344 break;
346 usage[unb++] = strbuf_detach(&sb, NULL);
349 /* parse: (<short>|<short>,<long>|<long>)[=?]? SP+ <help> */
350 while (strbuf_getline(&sb, stdin, '\n') != EOF) {
351 const char *s;
352 struct option *o;
354 if (!sb.len)
355 continue;
357 ALLOC_GROW(opts, onb + 1, osz);
358 memset(opts + onb, 0, sizeof(opts[onb]));
360 o = &opts[onb++];
361 s = strchr(sb.buf, ' ');
362 if (!s || *sb.buf == ' ') {
363 o->type = OPTION_GROUP;
364 o->help = xstrdup(skipspaces(sb.buf));
365 continue;
368 o->type = OPTION_CALLBACK;
369 o->help = xstrdup(skipspaces(s));
370 o->value = &parsed;
371 o->flags = PARSE_OPT_NOARG;
372 o->callback = &parseopt_dump;
373 while (s > sb.buf && strchr("*=?!", s[-1])) {
374 switch (*--s) {
375 case '=':
376 o->flags &= ~PARSE_OPT_NOARG;
377 break;
378 case '?':
379 o->flags &= ~PARSE_OPT_NOARG;
380 o->flags |= PARSE_OPT_OPTARG;
381 break;
382 case '!':
383 o->flags |= PARSE_OPT_NONEG;
384 break;
385 case '*':
386 o->flags |= PARSE_OPT_HIDDEN;
387 break;
391 if (s - sb.buf == 1) /* short option only */
392 o->short_name = *sb.buf;
393 else if (sb.buf[1] != ',') /* long option only */
394 o->long_name = xmemdupz(sb.buf, s - sb.buf);
395 else {
396 o->short_name = *sb.buf;
397 o->long_name = xmemdupz(sb.buf + 2, s - sb.buf - 2);
400 strbuf_release(&sb);
402 /* put an OPT_END() */
403 ALLOC_GROW(opts, onb + 1, osz);
404 memset(opts + onb, 0, sizeof(opts[onb]));
405 argc = parse_options(argc, argv, prefix, opts, usage,
406 keep_dashdash ? PARSE_OPT_KEEP_DASHDASH : 0 |
407 stop_at_non_option ? PARSE_OPT_STOP_AT_NON_OPTION : 0);
409 strbuf_addf(&parsed, " --");
410 sq_quote_argv(&parsed, argv, 0);
411 puts(parsed.buf);
412 return 0;
415 static int cmd_sq_quote(int argc, const char **argv)
417 struct strbuf buf = STRBUF_INIT;
419 if (argc)
420 sq_quote_argv(&buf, argv, 0);
421 printf("%s\n", buf.buf);
422 strbuf_release(&buf);
424 return 0;
427 static void die_no_single_rev(int quiet)
429 if (quiet)
430 exit(1);
431 else
432 die("Needed a single revision");
435 static const char builtin_rev_parse_usage[] =
436 "git rev-parse --parseopt [options] -- [<args>...]\n"
437 " or: git rev-parse --sq-quote [<arg>...]\n"
438 " or: git rev-parse [options] [<arg>...]\n"
439 "\n"
440 "Run \"git rev-parse --parseopt -h\" for more information on the first usage.";
442 int cmd_rev_parse(int argc, const char **argv, const char *prefix)
444 int i, as_is = 0, verify = 0, quiet = 0, revs_count = 0, type = 0;
445 unsigned char sha1[20];
446 const char *name = NULL;
448 if (argc > 1 && !strcmp("--parseopt", argv[1]))
449 return cmd_parseopt(argc - 1, argv + 1, prefix);
451 if (argc > 1 && !strcmp("--sq-quote", argv[1]))
452 return cmd_sq_quote(argc - 2, argv + 2);
454 if (argc > 1 && !strcmp("-h", argv[1]))
455 usage(builtin_rev_parse_usage);
457 prefix = setup_git_directory();
458 git_config(git_default_config, NULL);
459 for (i = 1; i < argc; i++) {
460 const char *arg = argv[i];
462 if (as_is) {
463 if (show_file(arg) && as_is < 2)
464 verify_filename(prefix, arg);
465 continue;
467 if (!strcmp(arg,"-n")) {
468 if (++i >= argc)
469 die("-n requires an argument");
470 if ((filter & DO_FLAGS) && (filter & DO_REVS)) {
471 show(arg);
472 show(argv[i]);
474 continue;
476 if (!prefixcmp(arg, "-n")) {
477 if ((filter & DO_FLAGS) && (filter & DO_REVS))
478 show(arg);
479 continue;
482 if (*arg == '-') {
483 if (!strcmp(arg, "--")) {
484 as_is = 2;
485 /* Pass on the "--" if we show anything but files.. */
486 if (filter & (DO_FLAGS | DO_REVS))
487 show_file(arg);
488 continue;
490 if (!strcmp(arg, "--default")) {
491 def = argv[i+1];
492 i++;
493 continue;
495 if (!strcmp(arg, "--revs-only")) {
496 filter &= ~DO_NOREV;
497 continue;
499 if (!strcmp(arg, "--no-revs")) {
500 filter &= ~DO_REVS;
501 continue;
503 if (!strcmp(arg, "--flags")) {
504 filter &= ~DO_NONFLAGS;
505 continue;
507 if (!strcmp(arg, "--no-flags")) {
508 filter &= ~DO_FLAGS;
509 continue;
511 if (!strcmp(arg, "--verify")) {
512 filter &= ~(DO_FLAGS|DO_NOREV);
513 verify = 1;
514 continue;
516 if (!strcmp(arg, "--quiet") || !strcmp(arg, "-q")) {
517 quiet = 1;
518 continue;
520 if (!strcmp(arg, "--short") ||
521 !prefixcmp(arg, "--short=")) {
522 filter &= ~(DO_FLAGS|DO_NOREV);
523 verify = 1;
524 abbrev = DEFAULT_ABBREV;
525 if (arg[7] == '=')
526 abbrev = strtoul(arg + 8, NULL, 10);
527 if (abbrev < MINIMUM_ABBREV)
528 abbrev = MINIMUM_ABBREV;
529 else if (40 <= abbrev)
530 abbrev = 40;
531 continue;
533 if (!strcmp(arg, "--sq")) {
534 output_sq = 1;
535 continue;
537 if (!strcmp(arg, "--not")) {
538 show_type ^= REVERSED;
539 continue;
541 if (!strcmp(arg, "--symbolic")) {
542 symbolic = SHOW_SYMBOLIC_ASIS;
543 continue;
545 if (!strcmp(arg, "--symbolic-full-name")) {
546 symbolic = SHOW_SYMBOLIC_FULL;
547 continue;
549 if (!prefixcmp(arg, "--abbrev-ref") &&
550 (!arg[12] || arg[12] == '=')) {
551 abbrev_ref = 1;
552 abbrev_ref_strict = warn_ambiguous_refs;
553 if (arg[12] == '=') {
554 if (!strcmp(arg + 13, "strict"))
555 abbrev_ref_strict = 1;
556 else if (!strcmp(arg + 13, "loose"))
557 abbrev_ref_strict = 0;
558 else
559 die("unknown mode for %s", arg);
561 continue;
563 if (!strcmp(arg, "--all")) {
564 for_each_ref(show_reference, NULL);
565 continue;
567 if (!strcmp(arg, "--bisect")) {
568 for_each_ref_in("refs/bisect/bad", show_reference, NULL);
569 for_each_ref_in("refs/bisect/good", anti_reference, NULL);
570 continue;
572 if (!strcmp(arg, "--branches")) {
573 for_each_branch_ref(show_reference, NULL);
574 continue;
576 if (!strcmp(arg, "--tags")) {
577 for_each_tag_ref(show_reference, NULL);
578 continue;
580 if (!strcmp(arg, "--remotes")) {
581 for_each_remote_ref(show_reference, NULL);
582 continue;
584 if (!strcmp(arg, "--show-prefix")) {
585 if (prefix)
586 puts(prefix);
587 continue;
589 if (!strcmp(arg, "--show-cdup")) {
590 const char *pfx = prefix;
591 if (!is_inside_work_tree()) {
592 const char *work_tree =
593 get_git_work_tree();
594 if (work_tree)
595 printf("%s\n", work_tree);
596 continue;
598 while (pfx) {
599 pfx = strchr(pfx, '/');
600 if (pfx) {
601 pfx++;
602 printf("../");
605 putchar('\n');
606 continue;
608 if (!strcmp(arg, "--git-dir")) {
609 const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
610 static char cwd[PATH_MAX];
611 if (gitdir) {
612 puts(gitdir);
613 continue;
615 if (!prefix) {
616 puts(".git");
617 continue;
619 if (!getcwd(cwd, PATH_MAX))
620 die_errno("unable to get current working directory");
621 printf("%s/.git\n", cwd);
622 continue;
624 if (!strcmp(arg, "--is-inside-git-dir")) {
625 printf("%s\n", is_inside_git_dir() ? "true"
626 : "false");
627 continue;
629 if (!strcmp(arg, "--is-inside-work-tree")) {
630 printf("%s\n", is_inside_work_tree() ? "true"
631 : "false");
632 continue;
634 if (!strcmp(arg, "--is-bare-repository")) {
635 printf("%s\n", is_bare_repository() ? "true"
636 : "false");
637 continue;
639 if (!prefixcmp(arg, "--since=")) {
640 show_datestring("--max-age=", arg+8);
641 continue;
643 if (!prefixcmp(arg, "--after=")) {
644 show_datestring("--max-age=", arg+8);
645 continue;
647 if (!prefixcmp(arg, "--before=")) {
648 show_datestring("--min-age=", arg+9);
649 continue;
651 if (!prefixcmp(arg, "--until=")) {
652 show_datestring("--min-age=", arg+8);
653 continue;
655 if (show_flag(arg) && verify)
656 die_no_single_rev(quiet);
657 continue;
660 /* Not a flag argument */
661 if (try_difference(arg))
662 continue;
663 if (try_parent_shorthands(arg))
664 continue;
665 name = arg;
666 type = NORMAL;
667 if (*arg == '^') {
668 name++;
669 type = REVERSED;
671 if (!get_sha1(name, sha1)) {
672 if (verify)
673 revs_count++;
674 else
675 show_rev(type, sha1, name);
676 continue;
678 if (verify)
679 die_no_single_rev(quiet);
680 as_is = 1;
681 if (!show_file(arg))
682 continue;
683 verify_filename(prefix, arg);
685 if (verify) {
686 if (revs_count == 1) {
687 show_rev(type, sha1, name);
688 return 0;
689 } else if (revs_count == 0 && show_default())
690 return 0;
691 die_no_single_rev(quiet);
692 } else
693 show_default();
694 return 0;