git.c

   1 #include "builtin.h"
   2 #include "config.h"
   3 #include "exec_cmd.h"
   4 #include "help.h"
   5 #include "run-command.h"
   6 #include "alias.h"
   7
   8 #define RUN_SETUP               (1<<0)
   9 #define RUN_SETUP_GENTLY        (1<<1)
  10 #define USE_PAGER               (1<<2)
  11 /*
  12  * require working tree to be present -- anything uses this needs
  13  * RUN_SETUP for reading from the configuration file.
  14  */
  15 #define NEED_WORK_TREE          (1<<3)
  16 #define SUPPORT_SUPER_PREFIX    (1<<4)
  17 #define DELAY_PAGER_CONFIG      (1<<5)
  18 #define NO_PARSEOPT             (1<<6) /* parse-options is not used */
  19
  20 struct cmd_struct {
  21         const char *cmd;
  22         int (*fn)(int, const char **, const char *);
  23         unsigned int option;
  24 };
  25
  26 const char git_usage_string[] =
  27         N_("git [--version] [--help] [-C <path>] [-c <name>=<value>]\n"
  28            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  29            "           [-p | --paginate | --no-pager] [--no-replace-objects] [--bare]\n"
  30            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  31            "           <command> [<args>]");
  32
  33 const char git_more_info_string[] =
  34         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  35            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  36            "to read about a specific subcommand or concept.");
  37
  38 static int use_pager = -1;
  39
  40 static void list_builtins(struct string_list *list, unsigned int exclude_option);
  41
  42 static void exclude_helpers_from_list(struct string_list *list)
  43 {
  44         int i = 0;
  45
  46         while (i < list->nr) {
  47                 if (strstr(list->items[i].string, "--"))
  48                         unsorted_string_list_delete_item(list, i, 0);
  49                 else
  50                         i++;
  51         }
  52 }
  53
  54 static int match_token(const char *spec, int len, const char *token)
  55 {
  56         int token_len = strlen(token);
  57
  58         return len == token_len && !strncmp(spec, token, token_len);
  59 }
  60
  61 static int list_cmds(const char *spec)
  62 {
  63         struct string_list list = STRING_LIST_INIT_DUP;
  64         int i;
  65
  66         while (*spec) {
  67                 const char *sep = strchrnul(spec, ',');
  68                 int len = sep - spec;
  69
  70                 if (match_token(spec, len, "builtins"))
  71                         list_builtins(&list, 0);
  72                 else if (match_token(spec, len, "main"))
  73                         list_all_main_cmds(&list);
  74                 else if (match_token(spec, len, "others"))
  75                         list_all_other_cmds(&list);
  76                 else if (match_token(spec, len, "nohelpers"))
  77                         exclude_helpers_from_list(&list);
  78                 else if (match_token(spec, len, "alias"))
  79                         list_aliases(&list);
  80                 else if (match_token(spec, len, "config"))
  81                         list_cmds_by_config(&list);
  82                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
  83                         struct strbuf sb = STRBUF_INIT;
  84
  85                         strbuf_add(&sb, spec + 5, len - 5);
  86                         list_cmds_by_category(&list, sb.buf);
  87                         strbuf_release(&sb);
  88                 }
  89                 else
  90                         die(_("unsupported command listing type '%s'"), spec);
  91                 spec += len;
  92                 if (*spec == ',')
  93                         spec++;
  94         }
  95         for (i = 0; i < list.nr; i++)
  96                 puts(list.items[i].string);
  97         string_list_clear(&list, 0);
  98         return 0;
  99 }
 100
 101 static void commit_pager_choice(void) {
 102         switch (use_pager) {
 103         case 0:
 104                 setenv("GIT_PAGER", "cat", 1);
 105                 break;
 106         case 1:
 107                 setup_pager();
 108                 break;
 109         default:
 110                 break;
 111         }
 112 }
 113
 114 void setup_auto_pager(const char *cmd, int def)
 115 {
 116         if (use_pager != -1 || pager_in_use())
 117                 return;
 118         use_pager = check_pager_config(cmd);
 119         if (use_pager == -1)
 120                 use_pager = def;
 121         commit_pager_choice();
 122 }
 123
 124 static int handle_options(const char ***argv, int *argc, int *envchanged)
 125 {
 126         const char **orig_argv = *argv;
 127
 128         while (*argc > 0) {
 129                 const char *cmd = (*argv)[0];
 130                 if (cmd[0] != '-')
 131                         break;
 132
 133                 /*
 134                  * For legacy reasons, the "version" and "help"
 135                  * commands can be written with "--" prepended
 136                  * to make them look like flags.
 137                  */
 138                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
 139                         break;
 140
 141                 /*
 142                  * Check remaining flags.
 143                  */
 144                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
 145                         if (*cmd == '=')
 146                                 git_set_argv_exec_path(cmd + 1);
 147                         else {
 148                                 puts(git_exec_path());
 149                                 exit(0);
 150                         }
 151                 } else if (!strcmp(cmd, "--html-path")) {
 152                         puts(system_path(GIT_HTML_PATH));
 153                         exit(0);
 154                 } else if (!strcmp(cmd, "--man-path")) {
 155                         puts(system_path(GIT_MAN_PATH));
 156                         exit(0);
 157                 } else if (!strcmp(cmd, "--info-path")) {
 158                         puts(system_path(GIT_INFO_PATH));
 159                         exit(0);
 160                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 161                         use_pager = 1;
 162                 } else if (!strcmp(cmd, "--no-pager")) {
 163                         use_pager = 0;
 164                         if (envchanged)
 165                                 *envchanged = 1;
 166                 } else if (!strcmp(cmd, "--no-replace-objects")) {
 167                         check_replace_refs = 0;
 168                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 169                         if (envchanged)
 170                                 *envchanged = 1;
 171                 } else if (!strcmp(cmd, "--git-dir")) {
 172                         if (*argc < 2) {
 173                                 fprintf(stderr, _("no directory given for --git-dir\n" ));
 174                                 usage(git_usage_string);
 175                         }
 176                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 177                         if (envchanged)
 178                                 *envchanged = 1;
 179                         (*argv)++;
 180                         (*argc)--;
 181                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 182                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 183                         if (envchanged)
 184                                 *envchanged = 1;
 185                 } else if (!strcmp(cmd, "--namespace")) {
 186                         if (*argc < 2) {
 187                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 188                                 usage(git_usage_string);
 189                         }
 190                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 191                         if (envchanged)
 192                                 *envchanged = 1;
 193                         (*argv)++;
 194                         (*argc)--;
 195                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 196                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 197                         if (envchanged)
 198                                 *envchanged = 1;
 199                 } else if (!strcmp(cmd, "--work-tree")) {
 200                         if (*argc < 2) {
 201                                 fprintf(stderr, _("no directory given for --work-tree\n" ));
 202                                 usage(git_usage_string);
 203                         }
 204                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 205                         if (envchanged)
 206                                 *envchanged = 1;
 207                         (*argv)++;
 208                         (*argc)--;
 209                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 210                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 211                         if (envchanged)
 212                                 *envchanged = 1;
 213                 } else if (!strcmp(cmd, "--super-prefix")) {
 214                         if (*argc < 2) {
 215                                 fprintf(stderr, _("no prefix given for --super-prefix\n" ));
 216                                 usage(git_usage_string);
 217                         }
 218                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 219                         if (envchanged)
 220                                 *envchanged = 1;
 221                         (*argv)++;
 222                         (*argc)--;
 223                 } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 224                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 225                         if (envchanged)
 226                                 *envchanged = 1;
 227                 } else if (!strcmp(cmd, "--bare")) {
 228                         char *cwd = xgetcwd();
 229                         is_bare_repository_cfg = 1;
 230                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 231                         free(cwd);
 232                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 233                         if (envchanged)
 234                                 *envchanged = 1;
 235                 } else if (!strcmp(cmd, "-c")) {
 236                         if (*argc < 2) {
 237                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 238                                 usage(git_usage_string);
 239                         }
 240                         git_config_push_parameter((*argv)[1]);
 241                         (*argv)++;
 242                         (*argc)--;
 243                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 244                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 245                         if (envchanged)
 246                                 *envchanged = 1;
 247                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 248                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 249                         if (envchanged)
 250                                 *envchanged = 1;
 251                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
 252                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 253                         if (envchanged)
 254                                 *envchanged = 1;
 255                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 256                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 257                         if (envchanged)
 258                                 *envchanged = 1;
 259                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
 260                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 261                         if (envchanged)
 262                                 *envchanged = 1;
 263                 } else if (!strcmp(cmd, "--no-optional-locks")) {
 264                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 265                         if (envchanged)
 266                                 *envchanged = 1;
 267                 } else if (!strcmp(cmd, "--shallow-file")) {
 268                         (*argv)++;
 269                         (*argc)--;
 270                         set_alternate_shallow_file((*argv)[0], 1);
 271                         if (envchanged)
 272                                 *envchanged = 1;
 273                 } else if (!strcmp(cmd, "-C")) {
 274                         if (*argc < 2) {
 275                                 fprintf(stderr, _("no directory given for -C\n" ));
 276                                 usage(git_usage_string);
 277                         }
 278                         if ((*argv)[1][0]) {
 279                                 if (chdir((*argv)[1]))
 280                                         die_errno("cannot change to '%s'", (*argv)[1]);
 281                                 if (envchanged)
 282                                         *envchanged = 1;
 283                         }
 284                         (*argv)++;
 285                         (*argc)--;
 286                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 287                         if (!strcmp(cmd, "parseopt")) {
 288                                 struct string_list list = STRING_LIST_INIT_DUP;
 289                                 int i;
 290
 291                                 list_builtins(&list, NO_PARSEOPT);
 292                                 for (i = 0; i < list.nr; i++)
 293                                         printf("%s ", list.items[i].string);
 294                                 string_list_clear(&list, 0);
 295                                 exit(0);
 296                         } else {
 297                                 exit(list_cmds(cmd));
 298                         }
 299                 } else {
 300                         fprintf(stderr, _("unknown option: %s\n"), cmd);
 301                         usage(git_usage_string);
 302                 }
 303
 304                 (*argv)++;
 305                 (*argc)--;
 306         }
 307         return (*argv) - orig_argv;
 308 }
 309
 310 static int handle_alias(int *argcp, const char ***argv)
 311 {
 312         int envchanged = 0, ret = 0, saved_errno = errno;
 313         int count, option_count;
 314         const char **new_argv;
 315         const char *alias_command;
 316         char *alias_string;
 317
 318         alias_command = (*argv)[0];
 319         alias_string = alias_lookup(alias_command);
 320         if (alias_string) {
 321                 if (alias_string[0] == '!') {
 322                         struct child_process child = CHILD_PROCESS_INIT;
 323                         int nongit_ok;
 324
 325                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 326                         setup_git_directory_gently(&nongit_ok);
 327
 328                         commit_pager_choice();
 329
 330                         child.use_shell = 1;
 331                         argv_array_push(&child.args, alias_string + 1);
 332                         argv_array_pushv(&child.args, (*argv) + 1);
 333
 334                         ret = run_command(&child);
 335                         if (ret >= 0)   /* normal exit */
 336                                 exit(ret);
 337
 338                         die_errno("while expanding alias '%s': '%s'",
 339                             alias_command, alias_string + 1);
 340                 }
 341                 count = split_cmdline(alias_string, &new_argv);
 342                 if (count < 0)
 343                         die("Bad alias.%s string: %s", alias_command,
 344                             split_cmdline_strerror(count));
 345                 option_count = handle_options(&new_argv, &count, &envchanged);
 346                 if (envchanged)
 347                         die("alias '%s' changes environment variables.\n"
 348                                  "You can use '!git' in the alias to do this",
 349                                  alias_command);
 350                 memmove(new_argv - option_count, new_argv,
 351                                 count * sizeof(char *));
 352                 new_argv -= option_count;
 353
 354                 if (count < 1)
 355                         die("empty alias for %s", alias_command);
 356
 357                 if (!strcmp(alias_command, new_argv[0]))
 358                         die("recursive alias: %s", alias_command);
 359
 360                 trace_argv_printf(new_argv,
 361                                   "trace: alias expansion: %s =>",
 362                                   alias_command);
 363
 364                 REALLOC_ARRAY(new_argv, count + *argcp);
 365                 /* insert after command name */
 366                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 367
 368                 *argv = new_argv;
 369                 *argcp += count - 1;
 370
 371                 ret = 1;
 372         }
 373
 374         errno = saved_errno;
 375
 376         return ret;
 377 }
 378
 379 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 380 {
 381         int status, help;
 382         struct stat st;
 383         const char *prefix;
 384
 385         prefix = NULL;
 386         help = argc == 2 && !strcmp(argv[1], "-h");
 387         if (!help) {
 388                 if (p->option & RUN_SETUP)
 389                         prefix = setup_git_directory();
 390                 else if (p->option & RUN_SETUP_GENTLY) {
 391                         int nongit_ok;
 392                         prefix = setup_git_directory_gently(&nongit_ok);
 393                 }
 394
 395                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
 396                     !(p->option & DELAY_PAGER_CONFIG))
 397                         use_pager = check_pager_config(p->cmd);
 398                 if (use_pager == -1 && p->option & USE_PAGER)
 399                         use_pager = 1;
 400
 401                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 402                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 403                         trace_repo_setup(prefix);
 404         }
 405         commit_pager_choice();
 406
 407         if (!help && get_super_prefix()) {
 408                 if (!(p->option & SUPPORT_SUPER_PREFIX))
 409                         die("%s doesn't support --super-prefix", p->cmd);
 410         }
 411
 412         if (!help && p->option & NEED_WORK_TREE)
 413                 setup_work_tree();
 414
 415         trace_argv_printf(argv, "trace: built-in: git");
 416
 417         status = p->fn(argc, argv, prefix);
 418         if (status)
 419                 return status;
 420
 421         /* Somebody closed stdout? */
 422         if (fstat(fileno(stdout), &st))
 423                 return 0;
 424         /* Ignore write errors for pipes and sockets.. */
 425         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 426                 return 0;
 427
 428         /* Check for ENOSPC and EIO errors.. */
 429         if (fflush(stdout))
 430                 die_errno("write failure on standard output");
 431         if (ferror(stdout))
 432                 die("unknown write failure on standard output");
 433         if (fclose(stdout))
 434                 die_errno("close failed on standard output");
 435         return 0;
 436 }
 437
 438 static struct cmd_struct commands[] = {
 439         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 440         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 441         { "annotate", cmd_annotate, RUN_SETUP | NO_PARSEOPT },
 442         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 443         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 444         { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 445         { "blame", cmd_blame, RUN_SETUP },
 446         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 447         { "bundle", cmd_bundle, RUN_SETUP_GENTLY | NO_PARSEOPT },
 448         { "cat-file", cmd_cat_file, RUN_SETUP },
 449         { "check-attr", cmd_check_attr, RUN_SETUP },
 450         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 451         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 452         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 453         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 454         { "checkout-index", cmd_checkout_index,
 455                 RUN_SETUP | NEED_WORK_TREE},
 456         { "cherry", cmd_cherry, RUN_SETUP },
 457         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 458         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 459         { "clone", cmd_clone },
 460         { "column", cmd_column, RUN_SETUP_GENTLY },
 461         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 462         { "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
 463         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 464         { "count-objects", cmd_count_objects, RUN_SETUP },
 465         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 466         { "describe", cmd_describe, RUN_SETUP },
 467         { "diff", cmd_diff, NO_PARSEOPT },
 468         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 469         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 470         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 471         { "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
 472         { "fast-export", cmd_fast_export, RUN_SETUP },
 473         { "fetch", cmd_fetch, RUN_SETUP },
 474         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 475         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 476         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 477         { "format-patch", cmd_format_patch, RUN_SETUP },
 478         { "fsck", cmd_fsck, RUN_SETUP },
 479         { "fsck-objects", cmd_fsck, RUN_SETUP },
 480         { "gc", cmd_gc, RUN_SETUP },
 481         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 482         { "grep", cmd_grep, RUN_SETUP_GENTLY },
 483         { "hash-object", cmd_hash_object },
 484         { "help", cmd_help },
 485         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 486         { "init", cmd_init_db },
 487         { "init-db", cmd_init_db },
 488         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 489         { "log", cmd_log, RUN_SETUP },
 490         { "ls-files", cmd_ls_files, RUN_SETUP },
 491         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 492         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 493         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY | NO_PARSEOPT },
 494         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 495         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 496         { "merge-base", cmd_merge_base, RUN_SETUP },
 497         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 498         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 499         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 500         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 501         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 502         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 503         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 504         { "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
 505         { "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
 506         { "mktree", cmd_mktree, RUN_SETUP },
 507         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 508         { "name-rev", cmd_name_rev, RUN_SETUP },
 509         { "notes", cmd_notes, RUN_SETUP },
 510         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 511         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 512         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 513         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 514         { "pickaxe", cmd_blame, RUN_SETUP },
 515         { "prune", cmd_prune, RUN_SETUP },
 516         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 517         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 518         { "push", cmd_push, RUN_SETUP },
 519         { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 520         { "rebase--helper", cmd_rebase__helper, RUN_SETUP | NEED_WORK_TREE },
 521         { "receive-pack", cmd_receive_pack },
 522         { "reflog", cmd_reflog, RUN_SETUP },
 523         { "remote", cmd_remote, RUN_SETUP },
 524         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 525         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 526         { "repack", cmd_repack, RUN_SETUP },
 527         { "replace", cmd_replace, RUN_SETUP },
 528         { "rerere", cmd_rerere, RUN_SETUP },
 529         { "reset", cmd_reset, RUN_SETUP },
 530         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 531         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 532         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 533         { "rm", cmd_rm, RUN_SETUP },
 534         { "send-pack", cmd_send_pack, RUN_SETUP },
 535         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 536         { "show", cmd_show, RUN_SETUP },
 537         { "show-branch", cmd_show_branch, RUN_SETUP },
 538         { "show-ref", cmd_show_ref, RUN_SETUP },
 539         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 540         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 541         { "stripspace", cmd_stripspace },
 542         { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
 543         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 544         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 545         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 546         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 547         { "update-index", cmd_update_index, RUN_SETUP },
 548         { "update-ref", cmd_update_ref, RUN_SETUP },
 549         { "update-server-info", cmd_update_server_info, RUN_SETUP },
 550         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 551         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 552         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 553         { "verify-commit", cmd_verify_commit, RUN_SETUP },
 554         { "verify-pack", cmd_verify_pack },
 555         { "verify-tag", cmd_verify_tag, RUN_SETUP },
 556         { "version", cmd_version },
 557         { "whatchanged", cmd_whatchanged, RUN_SETUP },
 558         { "worktree", cmd_worktree, RUN_SETUP | NO_PARSEOPT },
 559         { "write-tree", cmd_write_tree, RUN_SETUP },
 560 };
 561
 562 static struct cmd_struct *get_builtin(const char *s)
 563 {
 564         int i;
 565         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 566                 struct cmd_struct *p = commands + i;
 567                 if (!strcmp(s, p->cmd))
 568                         return p;
 569         }
 570         return NULL;
 571 }
 572
 573 int is_builtin(const char *s)
 574 {
 575         return !!get_builtin(s);
 576 }
 577
 578 static void list_builtins(struct string_list *out, unsigned int exclude_option)
 579 {
 580         int i;
 581         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 582                 if (exclude_option &&
 583                     (commands[i].option & exclude_option))
 584                         continue;
 585                 string_list_append(out, commands[i].cmd);
 586         }
 587 }
 588
 589 #ifdef STRIP_EXTENSION
 590 static void strip_extension(const char **argv)
 591 {
 592         size_t len;
 593
 594         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 595                 argv[0] = xmemdupz(argv[0], len);
 596 }
 597 #else
 598 #define strip_extension(cmd)
 599 #endif
 600
 601 static void handle_builtin(int argc, const char **argv)
 602 {
 603         struct argv_array args = ARGV_ARRAY_INIT;
 604         const char *cmd;
 605         struct cmd_struct *builtin;
 606
 607         strip_extension(argv);
 608         cmd = argv[0];
 609
 610         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 611         if (argc > 1 && !strcmp(argv[1], "--help")) {
 612                 int i;
 613
 614                 argv[1] = argv[0];
 615                 argv[0] = cmd = "help";
 616
 617                 for (i = 0; i < argc; i++) {
 618                         argv_array_push(&args, argv[i]);
 619                         if (!i)
 620                                 argv_array_push(&args, "--exclude-guides");
 621                 }
 622
 623                 argc++;
 624                 argv = args.argv;
 625         }
 626
 627         builtin = get_builtin(cmd);
 628         if (builtin)
 629                 exit(run_builtin(builtin, argc, argv));
 630         argv_array_clear(&args);
 631 }
 632
 633 static void execv_dashed_external(const char **argv)
 634 {
 635         struct child_process cmd = CHILD_PROCESS_INIT;
 636         int status;
 637
 638         if (get_super_prefix())
 639                 die("%s doesn't support --super-prefix", argv[0]);
 640
 641         if (use_pager == -1 && !is_builtin(argv[0]))
 642                 use_pager = check_pager_config(argv[0]);
 643         commit_pager_choice();
 644
 645         argv_array_pushf(&cmd.args, "git-%s", argv[0]);
 646         argv_array_pushv(&cmd.args, argv + 1);
 647         cmd.clean_on_exit = 1;
 648         cmd.wait_after_clean = 1;
 649         cmd.silent_exec_failure = 1;
 650
 651         trace_argv_printf(cmd.args.argv, "trace: exec:");
 652
 653         /*
 654          * If we fail because the command is not found, it is
 655          * OK to return. Otherwise, we just pass along the status code,
 656          * or our usual generic code if we were not even able to exec
 657          * the program.
 658          */
 659         status = run_command(&cmd);
 660         if (status >= 0)
 661                 exit(status);
 662         else if (errno != ENOENT)
 663                 exit(128);
 664 }
 665
 666 static int run_argv(int *argcp, const char ***argv)
 667 {
 668         int done_alias = 0;
 669
 670         while (1) {
 671                 /*
 672                  * If we tried alias and futzed with our environment,
 673                  * it no longer is safe to invoke builtins directly in
 674                  * general.  We have to spawn them as dashed externals.
 675                  *
 676                  * NEEDSWORK: if we can figure out cases
 677                  * where it is safe to do, we can avoid spawning a new
 678                  * process.
 679                  */
 680                 if (!done_alias)
 681                         handle_builtin(*argcp, *argv);
 682
 683                 /* .. then try the external ones */
 684                 execv_dashed_external(*argv);
 685
 686                 /* It could be an alias -- this works around the insanity
 687                  * of overriding "git log" with "git show" by having
 688                  * alias.log = show
 689                  */
 690                 if (done_alias)
 691                         break;
 692                 if (!handle_alias(argcp, argv))
 693                         break;
 694                 done_alias = 1;
 695         }
 696
 697         return done_alias;
 698 }
 699
 700 int cmd_main(int argc, const char **argv)
 701 {
 702         const char *cmd;
 703         int done_help = 0;
 704
 705         cmd = argv[0];
 706         if (!cmd)
 707                 cmd = "git-help";
 708         else {
 709                 const char *slash = find_last_dir_sep(cmd);
 710                 if (slash)
 711                         cmd = slash + 1;
 712         }
 713
 714         trace_command_performance(argv);
 715
 716         /*
 717          * "git-xxxx" is the same as "git xxxx", but we obviously:
 718          *
 719          *  - cannot take flags in between the "git" and the "xxxx".
 720          *  - cannot execute it externally (since it would just do
 721          *    the same thing over again)
 722          *
 723          * So we just directly call the builtin handler, and die if
 724          * that one cannot handle it.
 725          */
 726         if (skip_prefix(cmd, "git-", &cmd)) {
 727                 argv[0] = cmd;
 728                 handle_builtin(argc, argv);
 729                 die("cannot handle %s as a builtin", cmd);
 730         }
 731
 732         /* Look for flags.. */
 733         argv++;
 734         argc--;
 735         handle_options(&argv, &argc, NULL);
 736         if (argc > 0) {
 737                 /* translate --help and --version into commands */
 738                 skip_prefix(argv[0], "--", &argv[0]);
 739         } else {
 740                 /* The user didn't specify a command; give them help */
 741                 commit_pager_choice();
 742                 printf("usage: %s\n\n", git_usage_string);
 743                 list_common_cmds_help();
 744                 printf("\n%s\n", _(git_more_info_string));
 745                 exit(1);
 746         }
 747         cmd = argv[0];
 748
 749         /*
 750          * We use PATH to find git commands, but we prepend some higher
 751          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 752          * environment, and the $(gitexecdir) from the Makefile at build
 753          * time.
 754          */
 755         setup_path();
 756
 757         while (1) {
 758                 int was_alias = run_argv(&argc, &argv);
 759                 if (errno != ENOENT)
 760                         break;
 761                 if (was_alias) {
 762                         fprintf(stderr, _("expansion of alias '%s' failed; "
 763                                           "'%s' is not a git command\n"),
 764                                 cmd, argv[0]);
 765                         exit(1);
 766                 }
 767                 if (!done_help) {
 768                         cmd = argv[0] = help_unknown_cmd(cmd);
 769                         done_help = 1;
 770                 } else
 771                         break;
 772         }
 773
 774         fprintf(stderr, _("failed to run command '%s': %s\n"),
 775                 cmd, strerror(errno));
 776
 777         return 1;
 778 }