builtin-for-each-ref.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "refs.h"
   4 #include "object.h"
   5 #include "tag.h"
   6 #include "commit.h"
   7 #include "tree.h"
   8 #include "blob.h"
   9 #include "quote.h"
  10 #include "parse-options.h"
  11 #include "remote.h"
  12
  13 /* Quoting styles */
  14 #define QUOTE_NONE 0
  15 #define QUOTE_SHELL 1
  16 #define QUOTE_PERL 2
  17 #define QUOTE_PYTHON 4
  18 #define QUOTE_TCL 8
  19
  20 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
  21
  22 struct atom_value {
  23         const char *s;
  24         unsigned long ul; /* used for sorting when not FIELD_STR */
  25 };
  26
  27 struct ref_sort {
  28         struct ref_sort *next;
  29         int atom; /* index into used_atom array */
  30         unsigned reverse : 1;
  31 };
  32
  33 struct refinfo {
  34         char *refname;
  35         unsigned char objectname[20];
  36         struct atom_value *value;
  37 };
  38
  39 static struct {
  40         const char *name;
  41         cmp_type cmp_type;
  42 } valid_atom[] = {
  43         { "refname" },
  44         { "objecttype" },
  45         { "objectsize", FIELD_ULONG },
  46         { "objectname" },
  47         { "tree" },
  48         { "parent" },
  49         { "numparent", FIELD_ULONG },
  50         { "object" },
  51         { "type" },
  52         { "tag" },
  53         { "author" },
  54         { "authorname" },
  55         { "authoremail" },
  56         { "authordate", FIELD_TIME },
  57         { "committer" },
  58         { "committername" },
  59         { "committeremail" },
  60         { "committerdate", FIELD_TIME },
  61         { "tagger" },
  62         { "taggername" },
  63         { "taggeremail" },
  64         { "taggerdate", FIELD_TIME },
  65         { "creator" },
  66         { "creatordate", FIELD_TIME },
  67         { "subject" },
  68         { "body" },
  69         { "contents" },
  70         { "upstream" },
  71 };
  72
  73 /*
  74  * An atom is a valid field atom listed above, possibly prefixed with
  75  * a "*" to denote deref_tag().
  76  *
  77  * We parse given format string and sort specifiers, and make a list
  78  * of properties that we need to extract out of objects.  refinfo
  79  * structure will hold an array of values extracted that can be
  80  * indexed with the "atom number", which is an index into this
  81  * array.
  82  */
  83 static const char **used_atom;
  84 static cmp_type *used_atom_type;
  85 static int used_atom_cnt, sort_atom_limit, need_tagged;
  86
  87 /*
  88  * Used to parse format string and sort specifiers
  89  */
  90 static int parse_atom(const char *atom, const char *ep)
  91 {
  92         const char *sp;
  93         int i, at;
  94
  95         sp = atom;
  96         if (*sp == '*' && sp < ep)
  97                 sp++; /* deref */
  98         if (ep <= sp)
  99                 die("malformed field name: %.*s", (int)(ep-atom), atom);
 100
 101         /* Do we have the atom already used elsewhere? */
 102         for (i = 0; i < used_atom_cnt; i++) {
 103                 int len = strlen(used_atom[i]);
 104                 if (len == ep - atom && !memcmp(used_atom[i], atom, len))
 105                         return i;
 106         }
 107
 108         /* Is the atom a valid one? */
 109         for (i = 0; i < ARRAY_SIZE(valid_atom); i++) {
 110                 int len = strlen(valid_atom[i].name);
 111                 /*
 112                  * If the atom name has a colon, strip it and everything after
 113                  * it off - it specifies the format for this entry, and
 114                  * shouldn't be used for checking against the valid_atom
 115                  * table.
 116                  */
 117                 const char *formatp = strchr(sp, ':');
 118                 if (!formatp || ep < formatp)
 119                         formatp = ep;
 120                 if (len == formatp - sp && !memcmp(valid_atom[i].name, sp, len))
 121                         break;
 122         }
 123
 124         if (ARRAY_SIZE(valid_atom) <= i)
 125                 die("unknown field name: %.*s", (int)(ep-atom), atom);
 126
 127         /* Add it in, including the deref prefix */
 128         at = used_atom_cnt;
 129         used_atom_cnt++;
 130         used_atom = xrealloc(used_atom,
 131                              (sizeof *used_atom) * used_atom_cnt);
 132         used_atom_type = xrealloc(used_atom_type,
 133                                   (sizeof(*used_atom_type) * used_atom_cnt));
 134         used_atom[at] = xmemdupz(atom, ep - atom);
 135         used_atom_type[at] = valid_atom[i].cmp_type;
 136         return at;
 137 }
 138
 139 /*
 140  * In a format string, find the next occurrence of %(atom).
 141  */
 142 static const char *find_next(const char *cp)
 143 {
 144         while (*cp) {
 145                 if (*cp == '%') {
 146                         /* %( is the start of an atom;
 147                          * %% is a quoted per-cent.
 148                          */
 149                         if (cp[1] == '(')
 150                                 return cp;
 151                         else if (cp[1] == '%')
 152                                 cp++; /* skip over two % */
 153                         /* otherwise this is a singleton, literal % */
 154                 }
 155                 cp++;
 156         }
 157         return NULL;
 158 }
 159
 160 /*
 161  * Make sure the format string is well formed, and parse out
 162  * the used atoms.
 163  */
 164 static int verify_format(const char *format)
 165 {
 166         const char *cp, *sp;
 167         for (cp = format; *cp && (sp = find_next(cp)); ) {
 168                 const char *ep = strchr(sp, ')');
 169                 if (!ep)
 170                         return error("malformed format string %s", sp);
 171                 /* sp points at "%(" and ep points at the closing ")" */
 172                 parse_atom(sp + 2, ep);
 173                 cp = ep + 1;
 174         }
 175         return 0;
 176 }
 177
 178 /*
 179  * Given an object name, read the object data and size, and return a
 180  * "struct object".  If the object data we are returning is also borrowed
 181  * by the "struct object" representation, set *eaten as well---it is a
 182  * signal from parse_object_buffer to us not to free the buffer.
 183  */
 184 static void *get_obj(const unsigned char *sha1, struct object **obj, unsigned long *sz, int *eaten)
 185 {
 186         enum object_type type;
 187         void *buf = read_sha1_file(sha1, &type, sz);
 188
 189         if (buf)
 190                 *obj = parse_object_buffer(sha1, type, *sz, buf, eaten);
 191         else
 192                 *obj = NULL;
 193         return buf;
 194 }
 195
 196 /* See grab_values */
 197 static void grab_common_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
 198 {
 199         int i;
 200
 201         for (i = 0; i < used_atom_cnt; i++) {
 202                 const char *name = used_atom[i];
 203                 struct atom_value *v = &val[i];
 204                 if (!!deref != (*name == '*'))
 205                         continue;
 206                 if (deref)
 207                         name++;
 208                 if (!strcmp(name, "objecttype"))
 209                         v->s = typename(obj->type);
 210                 else if (!strcmp(name, "objectsize")) {
 211                         char *s = xmalloc(40);
 212                         sprintf(s, "%lu", sz);
 213                         v->ul = sz;
 214                         v->s = s;
 215                 }
 216                 else if (!strcmp(name, "objectname")) {
 217                         char *s = xmalloc(41);
 218                         strcpy(s, sha1_to_hex(obj->sha1));
 219                         v->s = s;
 220                 }
 221         }
 222 }
 223
 224 /* See grab_values */
 225 static void grab_tag_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
 226 {
 227         int i;
 228         struct tag *tag = (struct tag *) obj;
 229
 230         for (i = 0; i < used_atom_cnt; i++) {
 231                 const char *name = used_atom[i];
 232                 struct atom_value *v = &val[i];
 233                 if (!!deref != (*name == '*'))
 234                         continue;
 235                 if (deref)
 236                         name++;
 237                 if (!strcmp(name, "tag"))
 238                         v->s = tag->tag;
 239                 else if (!strcmp(name, "type") && tag->tagged)
 240                         v->s = typename(tag->tagged->type);
 241                 else if (!strcmp(name, "object") && tag->tagged) {
 242                         char *s = xmalloc(41);
 243                         strcpy(s, sha1_to_hex(tag->tagged->sha1));
 244                         v->s = s;
 245                 }
 246         }
 247 }
 248
 249 static int num_parents(struct commit *commit)
 250 {
 251         struct commit_list *parents;
 252         int i;
 253
 254         for (i = 0, parents = commit->parents;
 255              parents;
 256              parents = parents->next)
 257                 i++;
 258         return i;
 259 }
 260
 261 /* See grab_values */
 262 static void grab_commit_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
 263 {
 264         int i;
 265         struct commit *commit = (struct commit *) obj;
 266
 267         for (i = 0; i < used_atom_cnt; i++) {
 268                 const char *name = used_atom[i];
 269                 struct atom_value *v = &val[i];
 270                 if (!!deref != (*name == '*'))
 271                         continue;
 272                 if (deref)
 273                         name++;
 274                 if (!strcmp(name, "tree")) {
 275                         char *s = xmalloc(41);
 276                         strcpy(s, sha1_to_hex(commit->tree->object.sha1));
 277                         v->s = s;
 278                 }
 279                 if (!strcmp(name, "numparent")) {
 280                         char *s = xmalloc(40);
 281                         v->ul = num_parents(commit);
 282                         sprintf(s, "%lu", v->ul);
 283                         v->s = s;
 284                 }
 285                 else if (!strcmp(name, "parent")) {
 286                         int num = num_parents(commit);
 287                         int i;
 288                         struct commit_list *parents;
 289                         char *s = xmalloc(41 * num + 1);
 290                         v->s = s;
 291                         for (i = 0, parents = commit->parents;
 292                              parents;
 293                              parents = parents->next, i = i + 41) {
 294                                 struct commit *parent = parents->item;
 295                                 strcpy(s+i, sha1_to_hex(parent->object.sha1));
 296                                 if (parents->next)
 297                                         s[i+40] = ' ';
 298                         }
 299                         if (!i)
 300                                 *s = '\0';
 301                 }
 302         }
 303 }
 304
 305 static const char *find_wholine(const char *who, int wholen, const char *buf, unsigned long sz)
 306 {
 307         const char *eol;
 308         while (*buf) {
 309                 if (!strncmp(buf, who, wholen) &&
 310                     buf[wholen] == ' ')
 311                         return buf + wholen + 1;
 312                 eol = strchr(buf, '\n');
 313                 if (!eol)
 314                         return "";
 315                 eol++;
 316                 if (*eol == '\n')
 317                         return ""; /* end of header */
 318                 buf = eol;
 319         }
 320         return "";
 321 }
 322
 323 static const char *copy_line(const char *buf)
 324 {
 325         const char *eol = strchrnul(buf, '\n');
 326         return xmemdupz(buf, eol - buf);
 327 }
 328
 329 static const char *copy_name(const char *buf)
 330 {
 331         const char *cp;
 332         for (cp = buf; *cp && *cp != '\n'; cp++) {
 333                 if (!strncmp(cp, " <", 2))
 334                         return xmemdupz(buf, cp - buf);
 335         }
 336         return "";
 337 }
 338
 339 static const char *copy_email(const char *buf)
 340 {
 341         const char *email = strchr(buf, '<');
 342         const char *eoemail = strchr(email, '>');
 343         if (!email || !eoemail)
 344                 return "";
 345         return xmemdupz(email, eoemail + 1 - email);
 346 }
 347
 348 static void grab_date(const char *buf, struct atom_value *v, const char *atomname)
 349 {
 350         const char *eoemail = strstr(buf, "> ");
 351         char *zone;
 352         unsigned long timestamp;
 353         long tz;
 354         enum date_mode date_mode = DATE_NORMAL;
 355         const char *formatp;
 356
 357         /*
 358          * We got here because atomname ends in "date" or "date<something>";
 359          * it's not possible that <something> is not ":<format>" because
 360          * parse_atom() wouldn't have allowed it, so we can assume that no
 361          * ":" means no format is specified, and use the default.
 362          */
 363         formatp = strchr(atomname, ':');
 364         if (formatp != NULL) {
 365                 formatp++;
 366                 date_mode = parse_date_format(formatp);
 367         }
 368
 369         if (!eoemail)
 370                 goto bad;
 371         timestamp = strtoul(eoemail + 2, &zone, 10);
 372         if (timestamp == ULONG_MAX)
 373                 goto bad;
 374         tz = strtol(zone, NULL, 10);
 375         if ((tz == LONG_MIN || tz == LONG_MAX) && errno == ERANGE)
 376                 goto bad;
 377         v->s = xstrdup(show_date(timestamp, tz, date_mode));
 378         v->ul = timestamp;
 379         return;
 380  bad:
 381         v->s = "";
 382         v->ul = 0;
 383 }
 384
 385 /* See grab_values */
 386 static void grab_person(const char *who, struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
 387 {
 388         int i;
 389         int wholen = strlen(who);
 390         const char *wholine = NULL;
 391
 392         for (i = 0; i < used_atom_cnt; i++) {
 393                 const char *name = used_atom[i];
 394                 struct atom_value *v = &val[i];
 395                 if (!!deref != (*name == '*'))
 396                         continue;
 397                 if (deref)
 398                         name++;
 399                 if (strncmp(who, name, wholen))
 400                         continue;
 401                 if (name[wholen] != 0 &&
 402                     strcmp(name + wholen, "name") &&
 403                     strcmp(name + wholen, "email") &&
 404                     prefixcmp(name + wholen, "date"))
 405                         continue;
 406                 if (!wholine)
 407                         wholine = find_wholine(who, wholen, buf, sz);
 408                 if (!wholine)
 409                         return; /* no point looking for it */
 410                 if (name[wholen] == 0)
 411                         v->s = copy_line(wholine);
 412                 else if (!strcmp(name + wholen, "name"))
 413                         v->s = copy_name(wholine);
 414                 else if (!strcmp(name + wholen, "email"))
 415                         v->s = copy_email(wholine);
 416                 else if (!prefixcmp(name + wholen, "date"))
 417                         grab_date(wholine, v, name);
 418         }
 419
 420         /* For a tag or a commit object, if "creator" or "creatordate" is
 421          * requested, do something special.
 422          */
 423         if (strcmp(who, "tagger") && strcmp(who, "committer"))
 424                 return; /* "author" for commit object is not wanted */
 425         if (!wholine)
 426                 wholine = find_wholine(who, wholen, buf, sz);
 427         if (!wholine)
 428                 return;
 429         for (i = 0; i < used_atom_cnt; i++) {
 430                 const char *name = used_atom[i];
 431                 struct atom_value *v = &val[i];
 432                 if (!!deref != (*name == '*'))
 433                         continue;
 434                 if (deref)
 435                         name++;
 436
 437                 if (!prefixcmp(name, "creatordate"))
 438                         grab_date(wholine, v, name);
 439                 else if (!strcmp(name, "creator"))
 440                         v->s = copy_line(wholine);
 441         }
 442 }
 443
 444 static void find_subpos(const char *buf, unsigned long sz, const char **sub, const char **body)
 445 {
 446         while (*buf) {
 447                 const char *eol = strchr(buf, '\n');
 448                 if (!eol)
 449                         return;
 450                 if (eol[1] == '\n') {
 451                         buf = eol + 1;
 452                         break; /* found end of header */
 453                 }
 454                 buf = eol + 1;
 455         }
 456         while (*buf == '\n')
 457                 buf++;
 458         if (!*buf)
 459                 return;
 460         *sub = buf; /* first non-empty line */
 461         buf = strchr(buf, '\n');
 462         if (!buf) {
 463                 *body = "";
 464                 return; /* no body */
 465         }
 466         while (*buf == '\n')
 467                 buf++; /* skip blank between subject and body */
 468         *body = buf;
 469 }
 470
 471 /* See grab_values */
 472 static void grab_sub_body_contents(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
 473 {
 474         int i;
 475         const char *subpos = NULL, *bodypos = NULL;
 476
 477         for (i = 0; i < used_atom_cnt; i++) {
 478                 const char *name = used_atom[i];
 479                 struct atom_value *v = &val[i];
 480                 if (!!deref != (*name == '*'))
 481                         continue;
 482                 if (deref)
 483                         name++;
 484                 if (strcmp(name, "subject") &&
 485                     strcmp(name, "body") &&
 486                     strcmp(name, "contents"))
 487                         continue;
 488                 if (!subpos)
 489                         find_subpos(buf, sz, &subpos, &bodypos);
 490                 if (!subpos)
 491                         return;
 492
 493                 if (!strcmp(name, "subject"))
 494                         v->s = copy_line(subpos);
 495                 else if (!strcmp(name, "body"))
 496                         v->s = xstrdup(bodypos);
 497                 else if (!strcmp(name, "contents"))
 498                         v->s = xstrdup(subpos);
 499         }
 500 }
 501
 502 /* We want to have empty print-string for field requests
 503  * that do not apply (e.g. "authordate" for a tag object)
 504  */
 505 static void fill_missing_values(struct atom_value *val)
 506 {
 507         int i;
 508         for (i = 0; i < used_atom_cnt; i++) {
 509                 struct atom_value *v = &val[i];
 510                 if (v->s == NULL)
 511                         v->s = "";
 512         }
 513 }
 514
 515 /*
 516  * val is a list of atom_value to hold returned values.  Extract
 517  * the values for atoms in used_atom array out of (obj, buf, sz).
 518  * when deref is false, (obj, buf, sz) is the object that is
 519  * pointed at by the ref itself; otherwise it is the object the
 520  * ref (which is a tag) refers to.
 521  */
 522 static void grab_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
 523 {
 524         grab_common_values(val, deref, obj, buf, sz);
 525         switch (obj->type) {
 526         case OBJ_TAG:
 527                 grab_tag_values(val, deref, obj, buf, sz);
 528                 grab_sub_body_contents(val, deref, obj, buf, sz);
 529                 grab_person("tagger", val, deref, obj, buf, sz);
 530                 break;
 531         case OBJ_COMMIT:
 532                 grab_commit_values(val, deref, obj, buf, sz);
 533                 grab_sub_body_contents(val, deref, obj, buf, sz);
 534                 grab_person("author", val, deref, obj, buf, sz);
 535                 grab_person("committer", val, deref, obj, buf, sz);
 536                 break;
 537         case OBJ_TREE:
 538                 // grab_tree_values(val, deref, obj, buf, sz);
 539                 break;
 540         case OBJ_BLOB:
 541                 // grab_blob_values(val, deref, obj, buf, sz);
 542                 break;
 543         default:
 544                 die("Eh?  Object of type %d?", obj->type);
 545         }
 546 }
 547
 548 /*
 549  * generate a format suitable for scanf from a ref_rev_parse_rules
 550  * rule, that is replace the "%.*s" spec with a "%s" spec
 551  */
 552 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
 553 {
 554         char *spec;
 555
 556         spec = strstr(rule, "%.*s");
 557         if (!spec || strstr(spec + 4, "%.*s"))
 558                 die("invalid rule in ref_rev_parse_rules: %s", rule);
 559
 560         /* copy all until spec */
 561         strncpy(scanf_fmt, rule, spec - rule);
 562         scanf_fmt[spec - rule] = '\0';
 563         /* copy new spec */
 564         strcat(scanf_fmt, "%s");
 565         /* copy remaining rule */
 566         strcat(scanf_fmt, spec + 4);
 567
 568         return;
 569 }
 570
 571 /*
 572  * Shorten the refname to an non-ambiguous form
 573  */
 574 static char *get_short_ref(const char *ref)
 575 {
 576         int i;
 577         static char **scanf_fmts;
 578         static int nr_rules;
 579         char *short_name;
 580
 581         /* pre generate scanf formats from ref_rev_parse_rules[] */
 582         if (!nr_rules) {
 583                 size_t total_len = 0;
 584
 585                 /* the rule list is NULL terminated, count them first */
 586                 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
 587                         /* no +1 because strlen("%s") < strlen("%.*s") */
 588                         total_len += strlen(ref_rev_parse_rules[nr_rules]);
 589
 590                 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
 591
 592                 total_len = 0;
 593                 for (i = 0; i < nr_rules; i++) {
 594                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
 595                                         + total_len;
 596                         gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
 597                         total_len += strlen(ref_rev_parse_rules[i]);
 598                 }
 599         }
 600
 601         /* bail out if there are no rules */
 602         if (!nr_rules)
 603                 return xstrdup(ref);
 604
 605         /* buffer for scanf result, at most ref must fit */
 606         short_name = xstrdup(ref);
 607
 608         /* skip first rule, it will always match */
 609         for (i = nr_rules - 1; i > 0 ; --i) {
 610                 int j;
 611                 int short_name_len;
 612
 613                 if (1 != sscanf(ref, scanf_fmts[i], short_name))
 614                         continue;
 615
 616                 short_name_len = strlen(short_name);
 617
 618                 /*
 619                  * check if the short name resolves to a valid ref,
 620                  * but use only rules prior to the matched one
 621                  */
 622                 for (j = 0; j < i; j++) {
 623                         const char *rule = ref_rev_parse_rules[j];
 624                         unsigned char short_objectname[20];
 625                         char refname[PATH_MAX];
 626
 627                         /*
 628                          * the short name is ambiguous, if it resolves
 629                          * (with this previous rule) to a valid ref
 630                          * read_ref() returns 0 on success
 631                          */
 632                         mksnpath(refname, sizeof(refname),
 633                                  rule, short_name_len, short_name);
 634                         if (!read_ref(refname, short_objectname))
 635                                 break;
 636                 }
 637
 638                 /*
 639                  * short name is non-ambiguous if all previous rules
 640                  * haven't resolved to a valid ref
 641                  */
 642                 if (j == i)
 643                         return short_name;
 644         }
 645
 646         free(short_name);
 647         return xstrdup(ref);
 648 }
 649
 650
 651 /*
 652  * Parse the object referred by ref, and grab needed value.
 653  */
 654 static void populate_value(struct refinfo *ref)
 655 {
 656         void *buf;
 657         struct object *obj;
 658         int eaten, i;
 659         unsigned long size;
 660         const unsigned char *tagged;
 661
 662         ref->value = xcalloc(sizeof(struct atom_value), used_atom_cnt);
 663
 664         buf = get_obj(ref->objectname, &obj, &size, &eaten);
 665         if (!buf)
 666                 die("missing object %s for %s",
 667                     sha1_to_hex(ref->objectname), ref->refname);
 668         if (!obj)
 669                 die("parse_object_buffer failed on %s for %s",
 670                     sha1_to_hex(ref->objectname), ref->refname);
 671
 672         /* Fill in specials first */
 673         for (i = 0; i < used_atom_cnt; i++) {
 674                 const char *name = used_atom[i];
 675                 struct atom_value *v = &ref->value[i];
 676                 int deref = 0;
 677                 const char *refname;
 678                 const char *formatp;
 679
 680                 if (*name == '*') {
 681                         deref = 1;
 682                         name++;
 683                 }
 684
 685                 if (!prefixcmp(name, "refname"))
 686                         refname = ref->refname;
 687                 else if(!prefixcmp(name, "upstream")) {
 688                         struct branch *branch;
 689                         /* only local branches may have an upstream */
 690                         if (prefixcmp(ref->refname, "refs/heads/"))
 691                                 continue;
 692                         branch = branch_get(ref->refname + 11);
 693
 694                         if (!branch || !branch->merge || !branch->merge[0] ||
 695                             !branch->merge[0]->dst)
 696                                 continue;
 697                         refname = branch->merge[0]->dst;
 698                 }
 699                 else
 700                         continue;
 701
 702                 formatp = strchr(name, ':');
 703                 /* look for "short" refname format */
 704                 if (formatp) {
 705                         formatp++;
 706                         if (!strcmp(formatp, "short"))
 707                                 refname = get_short_ref(refname);
 708                         else
 709                                 die("unknown %.*s format %s",
 710                                     (int)(formatp - name), name, formatp);
 711                 }
 712
 713                 if (!deref)
 714                         v->s = refname;
 715                 else {
 716                         int len = strlen(refname);
 717                         char *s = xmalloc(len + 4);
 718                         sprintf(s, "%s^{}", refname);
 719                         v->s = s;
 720                 }
 721         }
 722
 723         grab_values(ref->value, 0, obj, buf, size);
 724         if (!eaten)
 725                 free(buf);
 726
 727         /* If there is no atom that wants to know about tagged
 728          * object, we are done.
 729          */
 730         if (!need_tagged || (obj->type != OBJ_TAG))
 731                 return;
 732
 733         /* If it is a tag object, see if we use a value that derefs
 734          * the object, and if we do grab the object it refers to.
 735          */
 736         tagged = ((struct tag *)obj)->tagged->sha1;
 737
 738         /* NEEDSWORK: This derefs tag only once, which
 739          * is good to deal with chains of trust, but
 740          * is not consistent with what deref_tag() does
 741          * which peels the onion to the core.
 742          */
 743         buf = get_obj(tagged, &obj, &size, &eaten);
 744         if (!buf)
 745                 die("missing object %s for %s",
 746                     sha1_to_hex(tagged), ref->refname);
 747         if (!obj)
 748                 die("parse_object_buffer failed on %s for %s",
 749                     sha1_to_hex(tagged), ref->refname);
 750         grab_values(ref->value, 1, obj, buf, size);
 751         if (!eaten)
 752                 free(buf);
 753 }
 754
 755 /*
 756  * Given a ref, return the value for the atom.  This lazily gets value
 757  * out of the object by calling populate value.
 758  */
 759 static void get_value(struct refinfo *ref, int atom, struct atom_value **v)
 760 {
 761         if (!ref->value) {
 762                 populate_value(ref);
 763                 fill_missing_values(ref->value);
 764         }
 765         *v = &ref->value[atom];
 766 }
 767
 768 struct grab_ref_cbdata {
 769         struct refinfo **grab_array;
 770         const char **grab_pattern;
 771         int grab_cnt;
 772 };
 773
 774 /*
 775  * A call-back given to for_each_ref().  It is unfortunate that we
 776  * need to use global variables to pass extra information to this
 777  * function.
 778  */
 779 static int grab_single_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 780 {
 781         struct grab_ref_cbdata *cb = cb_data;
 782         struct refinfo *ref;
 783         int cnt;
 784
 785         if (*cb->grab_pattern) {
 786                 const char **pattern;
 787                 int namelen = strlen(refname);
 788                 for (pattern = cb->grab_pattern; *pattern; pattern++) {
 789                         const char *p = *pattern;
 790                         int plen = strlen(p);
 791
 792                         if ((plen <= namelen) &&
 793                             !strncmp(refname, p, plen) &&
 794                             (refname[plen] == '\0' ||
 795                              refname[plen] == '/' ||
 796                              p[plen-1] == '/'))
 797                                 break;
 798                         if (!fnmatch(p, refname, FNM_PATHNAME))
 799                                 break;
 800                 }
 801                 if (!*pattern)
 802                         return 0;
 803         }
 804
 805         /* We do not open the object yet; sort may only need refname
 806          * to do its job and the resulting list may yet to be pruned
 807          * by maxcount logic.
 808          */
 809         ref = xcalloc(1, sizeof(*ref));
 810         ref->refname = xstrdup(refname);
 811         hashcpy(ref->objectname, sha1);
 812
 813         cnt = cb->grab_cnt;
 814         cb->grab_array = xrealloc(cb->grab_array,
 815                                   sizeof(*cb->grab_array) * (cnt + 1));
 816         cb->grab_array[cnt++] = ref;
 817         cb->grab_cnt = cnt;
 818         return 0;
 819 }
 820
 821 static int cmp_ref_sort(struct ref_sort *s, struct refinfo *a, struct refinfo *b)
 822 {
 823         struct atom_value *va, *vb;
 824         int cmp;
 825         cmp_type cmp_type = used_atom_type[s->atom];
 826
 827         get_value(a, s->atom, &va);
 828         get_value(b, s->atom, &vb);
 829         switch (cmp_type) {
 830         case FIELD_STR:
 831                 cmp = strcmp(va->s, vb->s);
 832                 break;
 833         default:
 834                 if (va->ul < vb->ul)
 835                         cmp = -1;
 836                 else if (va->ul == vb->ul)
 837                         cmp = 0;
 838                 else
 839                         cmp = 1;
 840                 break;
 841         }
 842         return (s->reverse) ? -cmp : cmp;
 843 }
 844
 845 static struct ref_sort *ref_sort;
 846 static int compare_refs(const void *a_, const void *b_)
 847 {
 848         struct refinfo *a = *((struct refinfo **)a_);
 849         struct refinfo *b = *((struct refinfo **)b_);
 850         struct ref_sort *s;
 851
 852         for (s = ref_sort; s; s = s->next) {
 853                 int cmp = cmp_ref_sort(s, a, b);
 854                 if (cmp)
 855                         return cmp;
 856         }
 857         return 0;
 858 }
 859
 860 static void sort_refs(struct ref_sort *sort, struct refinfo **refs, int num_refs)
 861 {
 862         ref_sort = sort;
 863         qsort(refs, num_refs, sizeof(struct refinfo *), compare_refs);
 864 }
 865
 866 static void print_value(struct refinfo *ref, int atom, int quote_style)
 867 {
 868         struct atom_value *v;
 869         get_value(ref, atom, &v);
 870         switch (quote_style) {
 871         case QUOTE_NONE:
 872                 fputs(v->s, stdout);
 873                 break;
 874         case QUOTE_SHELL:
 875                 sq_quote_print(stdout, v->s);
 876                 break;
 877         case QUOTE_PERL:
 878                 perl_quote_print(stdout, v->s);
 879                 break;
 880         case QUOTE_PYTHON:
 881                 python_quote_print(stdout, v->s);
 882                 break;
 883         case QUOTE_TCL:
 884                 tcl_quote_print(stdout, v->s);
 885                 break;
 886         }
 887 }
 888
 889 static int hex1(char ch)
 890 {
 891         if ('0' <= ch && ch <= '9')
 892                 return ch - '0';
 893         else if ('a' <= ch && ch <= 'f')
 894                 return ch - 'a' + 10;
 895         else if ('A' <= ch && ch <= 'F')
 896                 return ch - 'A' + 10;
 897         return -1;
 898 }
 899 static int hex2(const char *cp)
 900 {
 901         if (cp[0] && cp[1])
 902                 return (hex1(cp[0]) << 4) | hex1(cp[1]);
 903         else
 904                 return -1;
 905 }
 906
 907 static void emit(const char *cp, const char *ep)
 908 {
 909         while (*cp && (!ep || cp < ep)) {
 910                 if (*cp == '%') {
 911                         if (cp[1] == '%')
 912                                 cp++;
 913                         else {
 914                                 int ch = hex2(cp + 1);
 915                                 if (0 <= ch) {
 916                                         putchar(ch);
 917                                         cp += 3;
 918                                         continue;
 919                                 }
 920                         }
 921                 }
 922                 putchar(*cp);
 923                 cp++;
 924         }
 925 }
 926
 927 static void show_ref(struct refinfo *info, const char *format, int quote_style)
 928 {
 929         const char *cp, *sp, *ep;
 930
 931         for (cp = format; *cp && (sp = find_next(cp)); cp = ep + 1) {
 932                 ep = strchr(sp, ')');
 933                 if (cp < sp)
 934                         emit(cp, sp);
 935                 print_value(info, parse_atom(sp + 2, ep), quote_style);
 936         }
 937         if (*cp) {
 938                 sp = cp + strlen(cp);
 939                 emit(cp, sp);
 940         }
 941         putchar('\n');
 942 }
 943
 944 static struct ref_sort *default_sort(void)
 945 {
 946         static const char cstr_name[] = "refname";
 947
 948         struct ref_sort *sort = xcalloc(1, sizeof(*sort));
 949
 950         sort->next = NULL;
 951         sort->atom = parse_atom(cstr_name, cstr_name + strlen(cstr_name));
 952         return sort;
 953 }
 954
 955 static int opt_parse_sort(const struct option *opt, const char *arg, int unset)
 956 {
 957         struct ref_sort **sort_tail = opt->value;
 958         struct ref_sort *s;
 959         int len;
 960
 961         if (!arg) /* should --no-sort void the list ? */
 962                 return -1;
 963
 964         *sort_tail = s = xcalloc(1, sizeof(*s));
 965
 966         if (*arg == '-') {
 967                 s->reverse = 1;
 968                 arg++;
 969         }
 970         len = strlen(arg);
 971         s->atom = parse_atom(arg, arg+len);
 972         return 0;
 973 }
 974
 975 static char const * const for_each_ref_usage[] = {
 976         "git for-each-ref [options] [<pattern>]",
 977         NULL
 978 };
 979
 980 int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 981 {
 982         int i, num_refs;
 983         const char *format = "%(objectname) %(objecttype)\t%(refname)";
 984         struct ref_sort *sort = NULL, **sort_tail = &sort;
 985         int maxcount = 0, quote_style = 0;
 986         struct refinfo **refs;
 987         struct grab_ref_cbdata cbdata;
 988
 989         struct option opts[] = {
 990                 OPT_BIT('s', "shell", &quote_style,
 991                         "quote placeholders suitably for shells", QUOTE_SHELL),
 992                 OPT_BIT('p', "perl",  &quote_style,
 993                         "quote placeholders suitably for perl", QUOTE_PERL),
 994                 OPT_BIT(0 , "python", &quote_style,
 995                         "quote placeholders suitably for python", QUOTE_PYTHON),
 996                 OPT_BIT(0 , "tcl",  &quote_style,
 997                         "quote placeholders suitably for tcl", QUOTE_TCL),
 998
 999                 OPT_GROUP(""),
1000                 OPT_INTEGER( 0 , "count", &maxcount, "show only <n> matched refs"),
1001                 OPT_STRING(  0 , "format", &format, "format", "format to use for the output"),
1002                 OPT_CALLBACK(0 , "sort", sort_tail, "key",
1003                             "field name to sort on", &opt_parse_sort),
1004                 OPT_END(),
1005         };
1006
1007         parse_options(argc, argv, opts, for_each_ref_usage, 0);
1008         if (maxcount < 0) {
1009                 error("invalid --count argument: `%d'", maxcount);
1010                 usage_with_options(for_each_ref_usage, opts);
1011         }
1012         if (HAS_MULTI_BITS(quote_style)) {
1013                 error("more than one quoting style?");
1014                 usage_with_options(for_each_ref_usage, opts);
1015         }
1016         if (verify_format(format))
1017                 usage_with_options(for_each_ref_usage, opts);
1018
1019         if (!sort)
1020                 sort = default_sort();
1021         sort_atom_limit = used_atom_cnt;
1022
1023         memset(&cbdata, 0, sizeof(cbdata));
1024         cbdata.grab_pattern = argv;
1025         for_each_ref(grab_single_ref, &cbdata);
1026         refs = cbdata.grab_array;
1027         num_refs = cbdata.grab_cnt;
1028
1029         for (i = 0; i < used_atom_cnt; i++) {
1030                 if (used_atom[i][0] == '*') {
1031                         need_tagged = 1;
1032                         break;
1033                 }
1034         }
1035
1036         sort_refs(sort, refs, num_refs);
1037
1038         if (!maxcount || num_refs < maxcount)
1039                 maxcount = num_refs;
1040         for (i = 0; i < maxcount; i++)
1041                 show_ref(refs[i], format, quote_style);
1042         return 0;
1043 }