trailer.c

   1 #include "git-compat-util.h"
   2 #include "config.h"
   3 #include "environment.h"
   4 #include "gettext.h"
   5 #include "string-list.h"
   6 #include "run-command.h"
   7 #include "commit.h"
   8 #include "trailer.h"
   9 #include "list.h"
  10 /*
  11  * Copyright (c) 2013, 2014 Christian Couder <chriscool@tuxfamily.org>
  12  */
  13
  14 struct conf_info {
  15         char *name;
  16         char *key;
  17         char *command;
  18         char *cmd;
  19         enum trailer_where where;
  20         enum trailer_if_exists if_exists;
  21         enum trailer_if_missing if_missing;
  22 };
  23
  24 static struct conf_info default_conf_info;
  25
  26 struct trailer_item {
  27         struct list_head list;
  28         /*
  29          * If this is not a trailer line, the line is stored in value
  30          * (excluding the terminating newline) and token is NULL.
  31          */
  32         char *token;
  33         char *value;
  34 };
  35
  36 struct arg_item {
  37         struct list_head list;
  38         char *token;
  39         char *value;
  40         struct conf_info conf;
  41 };
  42
  43 static LIST_HEAD(conf_head);
  44
  45 static char *separators = ":";
  46
  47 static int configured;
  48
  49 #define TRAILER_ARG_STRING "$ARG"
  50
  51 static const char *git_generated_prefixes[] = {
  52         "Signed-off-by: ",
  53         "(cherry picked from commit ",
  54         NULL
  55 };
  56
  57 /* Iterate over the elements of the list. */
  58 #define list_for_each_dir(pos, head, is_reverse) \
  59         for (pos = is_reverse ? (head)->prev : (head)->next; \
  60                 pos != (head); \
  61                 pos = is_reverse ? pos->prev : pos->next)
  62
  63 static int after_or_end(enum trailer_where where)
  64 {
  65         return (where == WHERE_AFTER) || (where == WHERE_END);
  66 }
  67
  68 /*
  69  * Return the length of the string not including any final
  70  * punctuation. E.g., the input "Signed-off-by:" would return
  71  * 13, stripping the trailing punctuation but retaining
  72  * internal punctuation.
  73  */
  74 static size_t token_len_without_separator(const char *token, size_t len)
  75 {
  76         while (len > 0 && !isalnum(token[len - 1]))
  77                 len--;
  78         return len;
  79 }
  80
  81 static int same_token(struct trailer_item *a, struct arg_item *b)
  82 {
  83         size_t a_len, b_len, min_len;
  84
  85         if (!a->token)
  86                 return 0;
  87
  88         a_len = token_len_without_separator(a->token, strlen(a->token));
  89         b_len = token_len_without_separator(b->token, strlen(b->token));
  90         min_len = (a_len > b_len) ? b_len : a_len;
  91
  92         return !strncasecmp(a->token, b->token, min_len);
  93 }
  94
  95 static int same_value(struct trailer_item *a, struct arg_item *b)
  96 {
  97         return !strcasecmp(a->value, b->value);
  98 }
  99
 100 static int same_trailer(struct trailer_item *a, struct arg_item *b)
 101 {
 102         return same_token(a, b) && same_value(a, b);
 103 }
 104
 105 static inline int is_blank_line(const char *str)
 106 {
 107         const char *s = str;
 108         while (*s && *s != '\n' && isspace(*s))
 109                 s++;
 110         return !*s || *s == '\n';
 111 }
 112
 113 static inline void strbuf_replace(struct strbuf *sb, const char *a, const char *b)
 114 {
 115         const char *ptr = strstr(sb->buf, a);
 116         if (ptr)
 117                 strbuf_splice(sb, ptr - sb->buf, strlen(a), b, strlen(b));
 118 }
 119
 120 static void free_trailer_item(struct trailer_item *item)
 121 {
 122         free(item->token);
 123         free(item->value);
 124         free(item);
 125 }
 126
 127 static void free_arg_item(struct arg_item *item)
 128 {
 129         free(item->conf.name);
 130         free(item->conf.key);
 131         free(item->conf.command);
 132         free(item->conf.cmd);
 133         free(item->token);
 134         free(item->value);
 135         free(item);
 136 }
 137
 138 static char last_non_space_char(const char *s)
 139 {
 140         int i;
 141         for (i = strlen(s) - 1; i >= 0; i--)
 142                 if (!isspace(s[i]))
 143                         return s[i];
 144         return '\0';
 145 }
 146
 147 static void print_tok_val(struct strbuf *out, const char *tok, const char *val)
 148 {
 149         char c;
 150
 151         if (!tok) {
 152                 strbuf_addf(out, "%s\n", val);
 153                 return;
 154         }
 155
 156         c = last_non_space_char(tok);
 157         if (!c)
 158                 return;
 159         if (strchr(separators, c))
 160                 strbuf_addf(out, "%s%s\n", tok, val);
 161         else
 162                 strbuf_addf(out, "%s%c %s\n", tok, separators[0], val);
 163 }
 164
 165 void format_trailers(const struct process_trailer_options *opts,
 166                      struct list_head *trailers,
 167                      struct strbuf *out)
 168 {
 169         struct list_head *pos;
 170         struct trailer_item *item;
 171         list_for_each(pos, trailers) {
 172                 item = list_entry(pos, struct trailer_item, list);
 173                 if ((!opts->trim_empty || strlen(item->value) > 0) &&
 174                     (!opts->only_trailers || item->token))
 175                         print_tok_val(out, item->token, item->value);
 176         }
 177 }
 178
 179 static struct trailer_item *trailer_from_arg(struct arg_item *arg_tok)
 180 {
 181         struct trailer_item *new_item = xcalloc(1, sizeof(*new_item));
 182         new_item->token = arg_tok->token;
 183         new_item->value = arg_tok->value;
 184         arg_tok->token = arg_tok->value = NULL;
 185         free_arg_item(arg_tok);
 186         return new_item;
 187 }
 188
 189 static void add_arg_to_input_list(struct trailer_item *on_tok,
 190                                   struct arg_item *arg_tok)
 191 {
 192         int aoe = after_or_end(arg_tok->conf.where);
 193         struct trailer_item *to_add = trailer_from_arg(arg_tok);
 194         if (aoe)
 195                 list_add(&to_add->list, &on_tok->list);
 196         else
 197                 list_add_tail(&to_add->list, &on_tok->list);
 198 }
 199
 200 static int check_if_different(struct trailer_item *in_tok,
 201                               struct arg_item *arg_tok,
 202                               int check_all,
 203                               struct list_head *head)
 204 {
 205         enum trailer_where where = arg_tok->conf.where;
 206         struct list_head *next_head;
 207         do {
 208                 if (same_trailer(in_tok, arg_tok))
 209                         return 0;
 210                 /*
 211                  * if we want to add a trailer after another one,
 212                  * we have to check those before this one
 213                  */
 214                 next_head = after_or_end(where) ? in_tok->list.prev
 215                                                 : in_tok->list.next;
 216                 if (next_head == head)
 217                         break;
 218                 in_tok = list_entry(next_head, struct trailer_item, list);
 219         } while (check_all);
 220         return 1;
 221 }
 222
 223 static char *apply_command(struct conf_info *conf, const char *arg)
 224 {
 225         struct strbuf cmd = STRBUF_INIT;
 226         struct strbuf buf = STRBUF_INIT;
 227         struct child_process cp = CHILD_PROCESS_INIT;
 228         char *result;
 229
 230         if (conf->cmd) {
 231                 strbuf_addstr(&cmd, conf->cmd);
 232                 strvec_push(&cp.args, cmd.buf);
 233                 if (arg)
 234                         strvec_push(&cp.args, arg);
 235         } else if (conf->command) {
 236                 strbuf_addstr(&cmd, conf->command);
 237                 if (arg)
 238                         strbuf_replace(&cmd, TRAILER_ARG_STRING, arg);
 239                 strvec_push(&cp.args, cmd.buf);
 240         }
 241         strvec_pushv(&cp.env, (const char **)local_repo_env);
 242         cp.no_stdin = 1;
 243         cp.use_shell = 1;
 244
 245         if (capture_command(&cp, &buf, 1024)) {
 246                 error(_("running trailer command '%s' failed"), cmd.buf);
 247                 strbuf_release(&buf);
 248                 result = xstrdup("");
 249         } else {
 250                 strbuf_trim(&buf);
 251                 result = strbuf_detach(&buf, NULL);
 252         }
 253
 254         strbuf_release(&cmd);
 255         return result;
 256 }
 257
 258 static void apply_item_command(struct trailer_item *in_tok, struct arg_item *arg_tok)
 259 {
 260         if (arg_tok->conf.command || arg_tok->conf.cmd) {
 261                 const char *arg;
 262                 if (arg_tok->value && arg_tok->value[0]) {
 263                         arg = arg_tok->value;
 264                 } else {
 265                         if (in_tok && in_tok->value)
 266                                 arg = xstrdup(in_tok->value);
 267                         else
 268                                 arg = xstrdup("");
 269                 }
 270                 arg_tok->value = apply_command(&arg_tok->conf, arg);
 271                 free((char *)arg);
 272         }
 273 }
 274
 275 static void apply_arg_if_exists(struct trailer_item *in_tok,
 276                                 struct arg_item *arg_tok,
 277                                 struct trailer_item *on_tok,
 278                                 struct list_head *head)
 279 {
 280         switch (arg_tok->conf.if_exists) {
 281         case EXISTS_DO_NOTHING:
 282                 free_arg_item(arg_tok);
 283                 break;
 284         case EXISTS_REPLACE:
 285                 apply_item_command(in_tok, arg_tok);
 286                 add_arg_to_input_list(on_tok, arg_tok);
 287                 list_del(&in_tok->list);
 288                 free_trailer_item(in_tok);
 289                 break;
 290         case EXISTS_ADD:
 291                 apply_item_command(in_tok, arg_tok);
 292                 add_arg_to_input_list(on_tok, arg_tok);
 293                 break;
 294         case EXISTS_ADD_IF_DIFFERENT:
 295                 apply_item_command(in_tok, arg_tok);
 296                 if (check_if_different(in_tok, arg_tok, 1, head))
 297                         add_arg_to_input_list(on_tok, arg_tok);
 298                 else
 299                         free_arg_item(arg_tok);
 300                 break;
 301         case EXISTS_ADD_IF_DIFFERENT_NEIGHBOR:
 302                 apply_item_command(in_tok, arg_tok);
 303                 if (check_if_different(on_tok, arg_tok, 0, head))
 304                         add_arg_to_input_list(on_tok, arg_tok);
 305                 else
 306                         free_arg_item(arg_tok);
 307                 break;
 308         default:
 309                 BUG("trailer.c: unhandled value %d",
 310                     arg_tok->conf.if_exists);
 311         }
 312 }
 313
 314 static void apply_arg_if_missing(struct list_head *head,
 315                                  struct arg_item *arg_tok)
 316 {
 317         enum trailer_where where;
 318         struct trailer_item *to_add;
 319
 320         switch (arg_tok->conf.if_missing) {
 321         case MISSING_DO_NOTHING:
 322                 free_arg_item(arg_tok);
 323                 break;
 324         case MISSING_ADD:
 325                 where = arg_tok->conf.where;
 326                 apply_item_command(NULL, arg_tok);
 327                 to_add = trailer_from_arg(arg_tok);
 328                 if (after_or_end(where))
 329                         list_add_tail(&to_add->list, head);
 330                 else
 331                         list_add(&to_add->list, head);
 332                 break;
 333         default:
 334                 BUG("trailer.c: unhandled value %d",
 335                     arg_tok->conf.if_missing);
 336         }
 337 }
 338
 339 static int find_same_and_apply_arg(struct list_head *head,
 340                                    struct arg_item *arg_tok)
 341 {
 342         struct list_head *pos;
 343         struct trailer_item *in_tok;
 344         struct trailer_item *on_tok;
 345
 346         enum trailer_where where = arg_tok->conf.where;
 347         int middle = (where == WHERE_AFTER) || (where == WHERE_BEFORE);
 348         int backwards = after_or_end(where);
 349         struct trailer_item *start_tok;
 350
 351         if (list_empty(head))
 352                 return 0;
 353
 354         start_tok = list_entry(backwards ? head->prev : head->next,
 355                                struct trailer_item,
 356                                list);
 357
 358         list_for_each_dir(pos, head, backwards) {
 359                 in_tok = list_entry(pos, struct trailer_item, list);
 360                 if (!same_token(in_tok, arg_tok))
 361                         continue;
 362                 on_tok = middle ? in_tok : start_tok;
 363                 apply_arg_if_exists(in_tok, arg_tok, on_tok, head);
 364                 return 1;
 365         }
 366         return 0;
 367 }
 368
 369 void process_trailers_lists(struct list_head *head,
 370                             struct list_head *arg_head)
 371 {
 372         struct list_head *pos, *p;
 373         struct arg_item *arg_tok;
 374
 375         list_for_each_safe(pos, p, arg_head) {
 376                 int applied = 0;
 377                 arg_tok = list_entry(pos, struct arg_item, list);
 378
 379                 list_del(pos);
 380
 381                 applied = find_same_and_apply_arg(head, arg_tok);
 382
 383                 if (!applied)
 384                         apply_arg_if_missing(head, arg_tok);
 385         }
 386 }
 387
 388 int trailer_set_where(enum trailer_where *item, const char *value)
 389 {
 390         if (!value)
 391                 *item = WHERE_DEFAULT;
 392         else if (!strcasecmp("after", value))
 393                 *item = WHERE_AFTER;
 394         else if (!strcasecmp("before", value))
 395                 *item = WHERE_BEFORE;
 396         else if (!strcasecmp("end", value))
 397                 *item = WHERE_END;
 398         else if (!strcasecmp("start", value))
 399                 *item = WHERE_START;
 400         else
 401                 return -1;
 402         return 0;
 403 }
 404
 405 int trailer_set_if_exists(enum trailer_if_exists *item, const char *value)
 406 {
 407         if (!value)
 408                 *item = EXISTS_DEFAULT;
 409         else if (!strcasecmp("addIfDifferent", value))
 410                 *item = EXISTS_ADD_IF_DIFFERENT;
 411         else if (!strcasecmp("addIfDifferentNeighbor", value))
 412                 *item = EXISTS_ADD_IF_DIFFERENT_NEIGHBOR;
 413         else if (!strcasecmp("add", value))
 414                 *item = EXISTS_ADD;
 415         else if (!strcasecmp("replace", value))
 416                 *item = EXISTS_REPLACE;
 417         else if (!strcasecmp("doNothing", value))
 418                 *item = EXISTS_DO_NOTHING;
 419         else
 420                 return -1;
 421         return 0;
 422 }
 423
 424 int trailer_set_if_missing(enum trailer_if_missing *item, const char *value)
 425 {
 426         if (!value)
 427                 *item = MISSING_DEFAULT;
 428         else if (!strcasecmp("doNothing", value))
 429                 *item = MISSING_DO_NOTHING;
 430         else if (!strcasecmp("add", value))
 431                 *item = MISSING_ADD;
 432         else
 433                 return -1;
 434         return 0;
 435 }
 436
 437 static void duplicate_conf(struct conf_info *dst, const struct conf_info *src)
 438 {
 439         *dst = *src;
 440         dst->name = xstrdup_or_null(src->name);
 441         dst->key = xstrdup_or_null(src->key);
 442         dst->command = xstrdup_or_null(src->command);
 443         dst->cmd = xstrdup_or_null(src->cmd);
 444 }
 445
 446 static struct arg_item *get_conf_item(const char *name)
 447 {
 448         struct list_head *pos;
 449         struct arg_item *item;
 450
 451         /* Look up item with same name */
 452         list_for_each(pos, &conf_head) {
 453                 item = list_entry(pos, struct arg_item, list);
 454                 if (!strcasecmp(item->conf.name, name))
 455                         return item;
 456         }
 457
 458         /* Item does not already exists, create it */
 459         CALLOC_ARRAY(item, 1);
 460         duplicate_conf(&item->conf, &default_conf_info);
 461         item->conf.name = xstrdup(name);
 462
 463         list_add_tail(&item->list, &conf_head);
 464
 465         return item;
 466 }
 467
 468 enum trailer_info_type { TRAILER_KEY, TRAILER_COMMAND, TRAILER_CMD,
 469                         TRAILER_WHERE, TRAILER_IF_EXISTS, TRAILER_IF_MISSING };
 470
 471 static struct {
 472         const char *name;
 473         enum trailer_info_type type;
 474 } trailer_config_items[] = {
 475         { "key", TRAILER_KEY },
 476         { "command", TRAILER_COMMAND },
 477         { "cmd", TRAILER_CMD },
 478         { "where", TRAILER_WHERE },
 479         { "ifexists", TRAILER_IF_EXISTS },
 480         { "ifmissing", TRAILER_IF_MISSING }
 481 };
 482
 483 static int git_trailer_default_config(const char *conf_key, const char *value,
 484                                       const struct config_context *ctx UNUSED,
 485                                       void *cb UNUSED)
 486 {
 487         const char *trailer_item, *variable_name;
 488
 489         if (!skip_prefix(conf_key, "trailer.", &trailer_item))
 490                 return 0;
 491
 492         variable_name = strrchr(trailer_item, '.');
 493         if (!variable_name) {
 494                 if (!strcmp(trailer_item, "where")) {
 495                         if (trailer_set_where(&default_conf_info.where,
 496                                               value) < 0)
 497                                 warning(_("unknown value '%s' for key '%s'"),
 498                                         value, conf_key);
 499                 } else if (!strcmp(trailer_item, "ifexists")) {
 500                         if (trailer_set_if_exists(&default_conf_info.if_exists,
 501                                                   value) < 0)
 502                                 warning(_("unknown value '%s' for key '%s'"),
 503                                         value, conf_key);
 504                 } else if (!strcmp(trailer_item, "ifmissing")) {
 505                         if (trailer_set_if_missing(&default_conf_info.if_missing,
 506                                                    value) < 0)
 507                                 warning(_("unknown value '%s' for key '%s'"),
 508                                         value, conf_key);
 509                 } else if (!strcmp(trailer_item, "separators")) {
 510                         if (!value)
 511                                 return config_error_nonbool(conf_key);
 512                         separators = xstrdup(value);
 513                 }
 514         }
 515         return 0;
 516 }
 517
 518 static int git_trailer_config(const char *conf_key, const char *value,
 519                               const struct config_context *ctx UNUSED,
 520                               void *cb UNUSED)
 521 {
 522         const char *trailer_item, *variable_name;
 523         struct arg_item *item;
 524         struct conf_info *conf;
 525         char *name = NULL;
 526         enum trailer_info_type type;
 527         int i;
 528
 529         if (!skip_prefix(conf_key, "trailer.", &trailer_item))
 530                 return 0;
 531
 532         variable_name = strrchr(trailer_item, '.');
 533         if (!variable_name)
 534                 return 0;
 535
 536         variable_name++;
 537         for (i = 0; i < ARRAY_SIZE(trailer_config_items); i++) {
 538                 if (strcmp(trailer_config_items[i].name, variable_name))
 539                         continue;
 540                 name = xstrndup(trailer_item,  variable_name - trailer_item - 1);
 541                 type = trailer_config_items[i].type;
 542                 break;
 543         }
 544
 545         if (!name)
 546                 return 0;
 547
 548         item = get_conf_item(name);
 549         conf = &item->conf;
 550         free(name);
 551
 552         switch (type) {
 553         case TRAILER_KEY:
 554                 if (conf->key)
 555                         warning(_("more than one %s"), conf_key);
 556                 if (!value)
 557                         return config_error_nonbool(conf_key);
 558                 conf->key = xstrdup(value);
 559                 break;
 560         case TRAILER_COMMAND:
 561                 if (conf->command)
 562                         warning(_("more than one %s"), conf_key);
 563                 if (!value)
 564                         return config_error_nonbool(conf_key);
 565                 conf->command = xstrdup(value);
 566                 break;
 567         case TRAILER_CMD:
 568                 if (conf->cmd)
 569                         warning(_("more than one %s"), conf_key);
 570                 if (!value)
 571                         return config_error_nonbool(conf_key);
 572                 conf->cmd = xstrdup(value);
 573                 break;
 574         case TRAILER_WHERE:
 575                 if (trailer_set_where(&conf->where, value))
 576                         warning(_("unknown value '%s' for key '%s'"), value, conf_key);
 577                 break;
 578         case TRAILER_IF_EXISTS:
 579                 if (trailer_set_if_exists(&conf->if_exists, value))
 580                         warning(_("unknown value '%s' for key '%s'"), value, conf_key);
 581                 break;
 582         case TRAILER_IF_MISSING:
 583                 if (trailer_set_if_missing(&conf->if_missing, value))
 584                         warning(_("unknown value '%s' for key '%s'"), value, conf_key);
 585                 break;
 586         default:
 587                 BUG("trailer.c: unhandled type %d", type);
 588         }
 589         return 0;
 590 }
 591
 592 void trailer_config_init(void)
 593 {
 594         if (configured)
 595                 return;
 596
 597         /* Default config must be setup first */
 598         default_conf_info.where = WHERE_END;
 599         default_conf_info.if_exists = EXISTS_ADD_IF_DIFFERENT_NEIGHBOR;
 600         default_conf_info.if_missing = MISSING_ADD;
 601         git_config(git_trailer_default_config, NULL);
 602         git_config(git_trailer_config, NULL);
 603         configured = 1;
 604 }
 605
 606 static const char *token_from_item(struct arg_item *item, char *tok)
 607 {
 608         if (item->conf.key)
 609                 return item->conf.key;
 610         if (tok)
 611                 return tok;
 612         return item->conf.name;
 613 }
 614
 615 static int token_matches_item(const char *tok, struct arg_item *item, size_t tok_len)
 616 {
 617         if (!strncasecmp(tok, item->conf.name, tok_len))
 618                 return 1;
 619         return item->conf.key ? !strncasecmp(tok, item->conf.key, tok_len) : 0;
 620 }
 621
 622 /*
 623  * If the given line is of the form
 624  * "<token><optional whitespace><separator>..." or "<separator>...", return the
 625  * location of the separator. Otherwise, return -1.  The optional whitespace
 626  * is allowed there primarily to allow things like "Bug #43" where <token> is
 627  * "Bug" and <separator> is "#".
 628  *
 629  * The separator-starts-line case (in which this function returns 0) is
 630  * distinguished from the non-well-formed-line case (in which this function
 631  * returns -1) because some callers of this function need such a distinction.
 632  */
 633 static ssize_t find_separator(const char *line, const char *separators)
 634 {
 635         int whitespace_found = 0;
 636         const char *c;
 637         for (c = line; *c; c++) {
 638                 if (strchr(separators, *c))
 639                         return c - line;
 640                 if (!whitespace_found && (isalnum(*c) || *c == '-'))
 641                         continue;
 642                 if (c != line && (*c == ' ' || *c == '\t')) {
 643                         whitespace_found = 1;
 644                         continue;
 645                 }
 646                 break;
 647         }
 648         return -1;
 649 }
 650
 651 /*
 652  * Obtain the token, value, and conf from the given trailer.
 653  *
 654  * separator_pos must not be 0, since the token cannot be an empty string.
 655  *
 656  * If separator_pos is -1, interpret the whole trailer as a token.
 657  */
 658 static void parse_trailer(struct strbuf *tok, struct strbuf *val,
 659                          const struct conf_info **conf, const char *trailer,
 660                          ssize_t separator_pos)
 661 {
 662         struct arg_item *item;
 663         size_t tok_len;
 664         struct list_head *pos;
 665
 666         if (separator_pos != -1) {
 667                 strbuf_add(tok, trailer, separator_pos);
 668                 strbuf_trim(tok);
 669                 strbuf_addstr(val, trailer + separator_pos + 1);
 670                 strbuf_trim(val);
 671         } else {
 672                 strbuf_addstr(tok, trailer);
 673                 strbuf_trim(tok);
 674         }
 675
 676         /* Lookup if the token matches something in the config */
 677         tok_len = token_len_without_separator(tok->buf, tok->len);
 678         if (conf)
 679                 *conf = &default_conf_info;
 680         list_for_each(pos, &conf_head) {
 681                 item = list_entry(pos, struct arg_item, list);
 682                 if (token_matches_item(tok->buf, item, tok_len)) {
 683                         char *tok_buf = strbuf_detach(tok, NULL);
 684                         if (conf)
 685                                 *conf = &item->conf;
 686                         strbuf_addstr(tok, token_from_item(item, tok_buf));
 687                         free(tok_buf);
 688                         break;
 689                 }
 690         }
 691 }
 692
 693 static struct trailer_item *add_trailer_item(struct list_head *head, char *tok,
 694                                              char *val)
 695 {
 696         struct trailer_item *new_item = xcalloc(1, sizeof(*new_item));
 697         new_item->token = tok;
 698         new_item->value = val;
 699         list_add_tail(&new_item->list, head);
 700         return new_item;
 701 }
 702
 703 static void add_arg_item(struct list_head *arg_head, char *tok, char *val,
 704                          const struct conf_info *conf,
 705                          const struct new_trailer_item *new_trailer_item)
 706 {
 707         struct arg_item *new_item = xcalloc(1, sizeof(*new_item));
 708         new_item->token = tok;
 709         new_item->value = val;
 710         duplicate_conf(&new_item->conf, conf);
 711         if (new_trailer_item) {
 712                 if (new_trailer_item->where != WHERE_DEFAULT)
 713                         new_item->conf.where = new_trailer_item->where;
 714                 if (new_trailer_item->if_exists != EXISTS_DEFAULT)
 715                         new_item->conf.if_exists = new_trailer_item->if_exists;
 716                 if (new_trailer_item->if_missing != MISSING_DEFAULT)
 717                         new_item->conf.if_missing = new_trailer_item->if_missing;
 718         }
 719         list_add_tail(&new_item->list, arg_head);
 720 }
 721
 722 void parse_trailers_from_config(struct list_head *config_head)
 723 {
 724         struct arg_item *item;
 725         struct list_head *pos;
 726
 727         /* Add an arg item for each configured trailer with a command */
 728         list_for_each(pos, &conf_head) {
 729                 item = list_entry(pos, struct arg_item, list);
 730                 if (item->conf.command)
 731                         add_arg_item(config_head,
 732                                      xstrdup(token_from_item(item, NULL)),
 733                                      xstrdup(""),
 734                                      &item->conf, NULL);
 735         }
 736 }
 737
 738 void parse_trailers_from_command_line_args(struct list_head *arg_head,
 739                                            struct list_head *new_trailer_head)
 740 {
 741         struct strbuf tok = STRBUF_INIT;
 742         struct strbuf val = STRBUF_INIT;
 743         const struct conf_info *conf;
 744         struct list_head *pos;
 745
 746         /*
 747          * In command-line arguments, '=' is accepted (in addition to the
 748          * separators that are defined).
 749          */
 750         char *cl_separators = xstrfmt("=%s", separators);
 751
 752         /* Add an arg item for each trailer on the command line */
 753         list_for_each(pos, new_trailer_head) {
 754                 struct new_trailer_item *tr =
 755                         list_entry(pos, struct new_trailer_item, list);
 756                 ssize_t separator_pos = find_separator(tr->text, cl_separators);
 757
 758                 if (separator_pos == 0) {
 759                         struct strbuf sb = STRBUF_INIT;
 760                         strbuf_addstr(&sb, tr->text);
 761                         strbuf_trim(&sb);
 762                         error(_("empty trailer token in trailer '%.*s'"),
 763                               (int) sb.len, sb.buf);
 764                         strbuf_release(&sb);
 765                 } else {
 766                         parse_trailer(&tok, &val, &conf, tr->text,
 767                                       separator_pos);
 768                         add_arg_item(arg_head,
 769                                      strbuf_detach(&tok, NULL),
 770                                      strbuf_detach(&val, NULL),
 771                                      conf, tr);
 772                 }
 773         }
 774
 775         free(cl_separators);
 776 }
 777
 778 static const char *next_line(const char *str)
 779 {
 780         const char *nl = strchrnul(str, '\n');
 781         return nl + !!*nl;
 782 }
 783
 784 /*
 785  * Return the position of the start of the last line. If len is 0, return -1.
 786  */
 787 static ssize_t last_line(const char *buf, size_t len)
 788 {
 789         ssize_t i;
 790         if (len == 0)
 791                 return -1;
 792         if (len == 1)
 793                 return 0;
 794         /*
 795          * Skip the last character (in addition to the null terminator),
 796          * because if the last character is a newline, it is considered as part
 797          * of the last line anyway.
 798          */
 799         i = len - 2;
 800
 801         for (; i >= 0; i--) {
 802                 if (buf[i] == '\n')
 803                         return i + 1;
 804         }
 805         return 0;
 806 }
 807
 808 /*
 809  * Find the end of the log message as an offset from the start of the input
 810  * (where callers of this function are interested in looking for a trailers
 811  * block in the same input). We have to consider two categories of content that
 812  * can come at the end of the input which we want to ignore (because they don't
 813  * belong in the log message):
 814  *
 815  * (1) the "patch part" which begins with a "---" divider and has patch
 816  * information (like the output of git-format-patch), and
 817  *
 818  * (2) any trailing comment lines, blank lines like in the output of "git
 819  * commit -v", or stuff below the "cut" (scissor) line.
 820  *
 821  * As a formula, the situation looks like this:
 822  *
 823  *     INPUT = LOG MESSAGE + IGNORED
 824  *
 825  * where IGNORED can be either of the two categories described above. It may be
 826  * that there is nothing to ignore. Now it may be the case that the LOG MESSAGE
 827  * contains a trailer block, but that's not the concern of this function.
 828  */
 829 static size_t find_end_of_log_message(const char *input, int no_divider)
 830 {
 831         size_t end;
 832         const char *s;
 833
 834         /* Assume the naive end of the input is already what we want. */
 835         end = strlen(input);
 836
 837         /* Optionally skip over any patch part ("---" line and below). */
 838         if (!no_divider) {
 839                 for (s = input; *s; s = next_line(s)) {
 840                         const char *v;
 841
 842                         if (skip_prefix(s, "---", &v) && isspace(*v)) {
 843                                 end = s - input;
 844                                 break;
 845                         }
 846                 }
 847         }
 848
 849         /* Skip over other ignorable bits. */
 850         return end - ignored_log_message_bytes(input, end);
 851 }
 852
 853 /*
 854  * Return the position of the first trailer line or len if there are no
 855  * trailers.
 856  */
 857 static size_t find_trailer_block_start(const char *buf, size_t len)
 858 {
 859         const char *s;
 860         ssize_t end_of_title, l;
 861         int only_spaces = 1;
 862         int recognized_prefix = 0, trailer_lines = 0, non_trailer_lines = 0;
 863         /*
 864          * Number of possible continuation lines encountered. This will be
 865          * reset to 0 if we encounter a trailer (since those lines are to be
 866          * considered continuations of that trailer), and added to
 867          * non_trailer_lines if we encounter a non-trailer (since those lines
 868          * are to be considered non-trailers).
 869          */
 870         int possible_continuation_lines = 0;
 871
 872         /* The first paragraph is the title and cannot be trailers */
 873         for (s = buf; s < buf + len; s = next_line(s)) {
 874                 if (s[0] == comment_line_char)
 875                         continue;
 876                 if (is_blank_line(s))
 877                         break;
 878         }
 879         end_of_title = s - buf;
 880
 881         /*
 882          * Get the start of the trailers by looking starting from the end for a
 883          * blank line before a set of non-blank lines that (i) are all
 884          * trailers, or (ii) contains at least one Git-generated trailer and
 885          * consists of at least 25% trailers.
 886          */
 887         for (l = last_line(buf, len);
 888              l >= end_of_title;
 889              l = last_line(buf, l)) {
 890                 const char *bol = buf + l;
 891                 const char **p;
 892                 ssize_t separator_pos;
 893
 894                 if (bol[0] == comment_line_char) {
 895                         non_trailer_lines += possible_continuation_lines;
 896                         possible_continuation_lines = 0;
 897                         continue;
 898                 }
 899                 if (is_blank_line(bol)) {
 900                         if (only_spaces)
 901                                 continue;
 902                         non_trailer_lines += possible_continuation_lines;
 903                         if (recognized_prefix &&
 904                             trailer_lines * 3 >= non_trailer_lines)
 905                                 return next_line(bol) - buf;
 906                         else if (trailer_lines && !non_trailer_lines)
 907                                 return next_line(bol) - buf;
 908                         return len;
 909                 }
 910                 only_spaces = 0;
 911
 912                 for (p = git_generated_prefixes; *p; p++) {
 913                         if (starts_with(bol, *p)) {
 914                                 trailer_lines++;
 915                                 possible_continuation_lines = 0;
 916                                 recognized_prefix = 1;
 917                                 goto continue_outer_loop;
 918                         }
 919                 }
 920
 921                 separator_pos = find_separator(bol, separators);
 922                 if (separator_pos >= 1 && !isspace(bol[0])) {
 923                         struct list_head *pos;
 924
 925                         trailer_lines++;
 926                         possible_continuation_lines = 0;
 927                         if (recognized_prefix)
 928                                 continue;
 929                         list_for_each(pos, &conf_head) {
 930                                 struct arg_item *item;
 931                                 item = list_entry(pos, struct arg_item, list);
 932                                 if (token_matches_item(bol, item,
 933                                                        separator_pos)) {
 934                                         recognized_prefix = 1;
 935                                         break;
 936                                 }
 937                         }
 938                 } else if (isspace(bol[0]))
 939                         possible_continuation_lines++;
 940                 else {
 941                         non_trailer_lines++;
 942                         non_trailer_lines += possible_continuation_lines;
 943                         possible_continuation_lines = 0;
 944                 }
 945 continue_outer_loop:
 946                 ;
 947         }
 948
 949         return len;
 950 }
 951
 952 static int ends_with_blank_line(const char *buf, size_t len)
 953 {
 954         ssize_t ll = last_line(buf, len);
 955         if (ll < 0)
 956                 return 0;
 957         return is_blank_line(buf + ll);
 958 }
 959
 960 static void unfold_value(struct strbuf *val)
 961 {
 962         struct strbuf out = STRBUF_INIT;
 963         size_t i;
 964
 965         strbuf_grow(&out, val->len);
 966         i = 0;
 967         while (i < val->len) {
 968                 char c = val->buf[i++];
 969                 if (c == '\n') {
 970                         /* Collapse continuation down to a single space. */
 971                         while (i < val->len && isspace(val->buf[i]))
 972                                 i++;
 973                         strbuf_addch(&out, ' ');
 974                 } else {
 975                         strbuf_addch(&out, c);
 976                 }
 977         }
 978
 979         /* Empty lines may have left us with whitespace cruft at the edges */
 980         strbuf_trim(&out);
 981
 982         /* output goes back to val as if we modified it in-place */
 983         strbuf_swap(&out, val);
 984         strbuf_release(&out);
 985 }
 986
 987 /*
 988  * Parse trailers in "str", populating the trailer info and "head"
 989  * linked list structure.
 990  */
 991 void parse_trailers(const struct process_trailer_options *opts,
 992                     struct trailer_info *info,
 993                     const char *str,
 994                     struct list_head *head)
 995 {
 996         struct strbuf tok = STRBUF_INIT;
 997         struct strbuf val = STRBUF_INIT;
 998         size_t i;
 999
1000         trailer_info_get(opts, str, info);
1001
1002         for (i = 0; i < info->trailer_nr; i++) {
1003                 int separator_pos;
1004                 char *trailer = info->trailers[i];
1005                 if (trailer[0] == comment_line_char)
1006                         continue;
1007                 separator_pos = find_separator(trailer, separators);
1008                 if (separator_pos >= 1) {
1009                         parse_trailer(&tok, &val, NULL, trailer,
1010                                       separator_pos);
1011                         if (opts->unfold)
1012                                 unfold_value(&val);
1013                         add_trailer_item(head,
1014                                          strbuf_detach(&tok, NULL),
1015                                          strbuf_detach(&val, NULL));
1016                 } else if (!opts->only_trailers) {
1017                         strbuf_addstr(&val, trailer);
1018                         strbuf_strip_suffix(&val, "\n");
1019                         add_trailer_item(head,
1020                                          NULL,
1021                                          strbuf_detach(&val, NULL));
1022                 }
1023         }
1024 }
1025
1026 void free_trailers(struct list_head *trailers)
1027 {
1028         struct list_head *pos, *p;
1029         list_for_each_safe(pos, p, trailers) {
1030                 list_del(pos);
1031                 free_trailer_item(list_entry(pos, struct trailer_item, list));
1032         }
1033 }
1034
1035 void trailer_info_get(const struct process_trailer_options *opts,
1036                       const char *str,
1037                       struct trailer_info *info)
1038 {
1039         size_t end_of_log_message = 0, trailer_block_start = 0;
1040         struct strbuf **trailer_lines, **ptr;
1041         char **trailer_strings = NULL;
1042         size_t nr = 0, alloc = 0;
1043         char **last = NULL;
1044
1045         trailer_config_init();
1046
1047         end_of_log_message = find_end_of_log_message(str, opts->no_divider);
1048         trailer_block_start = find_trailer_block_start(str, end_of_log_message);
1049
1050         trailer_lines = strbuf_split_buf(str + trailer_block_start,
1051                                          end_of_log_message - trailer_block_start,
1052                                          '\n',
1053                                          0);
1054         for (ptr = trailer_lines; *ptr; ptr++) {
1055                 if (last && isspace((*ptr)->buf[0])) {
1056                         struct strbuf sb = STRBUF_INIT;
1057                         strbuf_attach(&sb, *last, strlen(*last), strlen(*last));
1058                         strbuf_addbuf(&sb, *ptr);
1059                         *last = strbuf_detach(&sb, NULL);
1060                         continue;
1061                 }
1062                 ALLOC_GROW(trailer_strings, nr + 1, alloc);
1063                 trailer_strings[nr] = strbuf_detach(*ptr, NULL);
1064                 last = find_separator(trailer_strings[nr], separators) >= 1
1065                         ? &trailer_strings[nr]
1066                         : NULL;
1067                 nr++;
1068         }
1069         strbuf_list_free(trailer_lines);
1070
1071         info->blank_line_before_trailer = ends_with_blank_line(str,
1072                                                                trailer_block_start);
1073         info->trailer_block_start = trailer_block_start;
1074         info->trailer_block_end = end_of_log_message;
1075         info->trailers = trailer_strings;
1076         info->trailer_nr = nr;
1077 }
1078
1079 void trailer_info_release(struct trailer_info *info)
1080 {
1081         size_t i;
1082         for (i = 0; i < info->trailer_nr; i++)
1083                 free(info->trailers[i]);
1084         free(info->trailers);
1085 }
1086
1087 static void format_trailer_info(const struct process_trailer_options *opts,
1088                                 const struct trailer_info *info,
1089                                 struct strbuf *out)
1090 {
1091         size_t origlen = out->len;
1092         size_t i;
1093
1094         for (i = 0; i < info->trailer_nr; i++) {
1095                 char *trailer = info->trailers[i];
1096                 ssize_t separator_pos = find_separator(trailer, separators);
1097
1098                 if (separator_pos >= 1) {
1099                         struct strbuf tok = STRBUF_INIT;
1100                         struct strbuf val = STRBUF_INIT;
1101
1102                         parse_trailer(&tok, &val, NULL, trailer, separator_pos);
1103                         if (!opts->filter || opts->filter(&tok, opts->filter_data)) {
1104                                 if (opts->unfold)
1105                                         unfold_value(&val);
1106
1107                                 if (opts->separator && out->len != origlen)
1108                                         strbuf_addbuf(out, opts->separator);
1109                                 if (!opts->value_only)
1110                                         strbuf_addbuf(out, &tok);
1111                                 if (!opts->key_only && !opts->value_only) {
1112                                         if (opts->key_value_separator)
1113                                                 strbuf_addbuf(out, opts->key_value_separator);
1114                                         else
1115                                                 strbuf_addstr(out, ": ");
1116                                 }
1117                                 if (!opts->key_only)
1118                                         strbuf_addbuf(out, &val);
1119                                 if (!opts->separator)
1120                                         strbuf_addch(out, '\n');
1121                         }
1122                         strbuf_release(&tok);
1123                         strbuf_release(&val);
1124
1125                 } else if (!opts->only_trailers) {
1126                         if (opts->separator && out->len != origlen) {
1127                                 strbuf_addbuf(out, opts->separator);
1128                         }
1129                         strbuf_addstr(out, trailer);
1130                         if (opts->separator) {
1131                                 strbuf_rtrim(out);
1132                         }
1133                 }
1134         }
1135
1136 }
1137
1138 void format_trailers_from_commit(const struct process_trailer_options *opts,
1139                                  const char *msg,
1140                                  struct strbuf *out)
1141 {
1142         LIST_HEAD(trailer_objects);
1143         struct trailer_info info;
1144
1145         parse_trailers(opts, &info, msg, &trailer_objects);
1146
1147         /* If we want the whole block untouched, we can take the fast path. */
1148         if (!opts->only_trailers && !opts->unfold && !opts->filter &&
1149             !opts->separator && !opts->key_only && !opts->value_only &&
1150             !opts->key_value_separator) {
1151                 strbuf_add(out, msg + info.trailer_block_start,
1152                            info.trailer_block_end - info.trailer_block_start);
1153         } else
1154                 format_trailer_info(opts, &info, out);
1155
1156         free_trailers(&trailer_objects);
1157         trailer_info_release(&info);
1158 }
1159
1160 void trailer_iterator_init(struct trailer_iterator *iter, const char *msg)
1161 {
1162         struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
1163         strbuf_init(&iter->key, 0);
1164         strbuf_init(&iter->val, 0);
1165         opts.no_divider = 1;
1166         trailer_info_get(&opts, msg, &iter->internal.info);
1167         iter->internal.cur = 0;
1168 }
1169
1170 int trailer_iterator_advance(struct trailer_iterator *iter)
1171 {
1172         while (iter->internal.cur < iter->internal.info.trailer_nr) {
1173                 char *trailer = iter->internal.info.trailers[iter->internal.cur++];
1174                 int separator_pos = find_separator(trailer, separators);
1175
1176                 if (separator_pos < 1)
1177                         continue; /* not a real trailer */
1178
1179                 strbuf_reset(&iter->key);
1180                 strbuf_reset(&iter->val);
1181                 parse_trailer(&iter->key, &iter->val, NULL,
1182                               trailer, separator_pos);
1183                 /* Always unfold values during iteration. */
1184                 unfold_value(&iter->val);
1185                 return 1;
1186         }
1187         return 0;
1188 }
1189
1190 void trailer_iterator_release(struct trailer_iterator *iter)
1191 {
1192         trailer_info_release(&iter->internal.info);
1193         strbuf_release(&iter->val);
1194         strbuf_release(&iter->key);
1195 }