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