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 #include "shallow.h"
   8
   9 #define RUN_SETUP               (1<<0)
  10 #define RUN_SETUP_GENTLY        (1<<1)
  11 #define USE_PAGER               (1<<2)
  12 /*
  13  * require working tree to be present -- anything uses this needs
  14  * RUN_SETUP for reading from the configuration file.
  15  */
  16 #define NEED_WORK_TREE          (1<<3)
  17 #define SUPPORT_SUPER_PREFIX    (1<<4)
  18 #define DELAY_PAGER_CONFIG      (1<<5)
  19 #define NO_PARSEOPT             (1<<6) /* parse-options is not used */
  20
  21 struct cmd_struct {
  22         const char *cmd;
  23         int (*fn)(int, const char **, const char *);
  24         unsigned int option;
  25 };
  26
  27 const char git_usage_string[] =
  28         N_("git [--version] [--help] [-C <path>] [-c <name>=<value>]\n"
  29            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  30            "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
  31            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  32            "           <command> [<args>]");
  33
  34 const char git_more_info_string[] =
  35         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  36            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  37            "to read about a specific subcommand or concept.\n"
  38            "See 'git help git' for an overview of the system.");
  39
  40 static int use_pager = -1;
  41
  42 static void list_builtins(struct string_list *list, unsigned int exclude_option);
  43
  44 static void exclude_helpers_from_list(struct string_list *list)
  45 {
  46         int i = 0;
  47
  48         while (i < list->nr) {
  49                 if (strstr(list->items[i].string, "--"))
  50                         unsorted_string_list_delete_item(list, i, 0);
  51                 else
  52                         i++;
  53         }
  54 }
  55
  56 static int match_token(const char *spec, int len, const char *token)
  57 {
  58         int token_len = strlen(token);
  59
  60         return len == token_len && !strncmp(spec, token, token_len);
  61 }
  62
  63 static int list_cmds(const char *spec)
  64 {
  65         struct string_list list = STRING_LIST_INIT_DUP;
  66         int i;
  67         int nongit;
  68
  69         /*
  70         * Set up the repository so we can pick up any repo-level config (like
  71         * completion.commands).
  72         */
  73         setup_git_directory_gently(&nongit);
  74
  75         while (*spec) {
  76                 const char *sep = strchrnul(spec, ',');
  77                 int len = sep - spec;
  78
  79                 if (match_token(spec, len, "builtins"))
  80                         list_builtins(&list, 0);
  81                 else if (match_token(spec, len, "main"))
  82                         list_all_main_cmds(&list);
  83                 else if (match_token(spec, len, "others"))
  84                         list_all_other_cmds(&list);
  85                 else if (match_token(spec, len, "nohelpers"))
  86                         exclude_helpers_from_list(&list);
  87                 else if (match_token(spec, len, "alias"))
  88                         list_aliases(&list);
  89                 else if (match_token(spec, len, "config"))
  90                         list_cmds_by_config(&list);
  91                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
  92                         struct strbuf sb = STRBUF_INIT;
  93
  94                         strbuf_add(&sb, spec + 5, len - 5);
  95                         list_cmds_by_category(&list, sb.buf);
  96                         strbuf_release(&sb);
  97                 }
  98                 else
  99                         die(_("unsupported command listing type '%s'"), spec);
 100                 spec += len;
 101                 if (*spec == ',')
 102                         spec++;
 103         }
 104         for (i = 0; i < list.nr; i++)
 105                 puts(list.items[i].string);
 106         string_list_clear(&list, 0);
 107         return 0;
 108 }
 109
 110 static void commit_pager_choice(void)
 111 {
 112         switch (use_pager) {
 113         case 0:
 114                 setenv("GIT_PAGER", "cat", 1);
 115                 break;
 116         case 1:
 117                 setup_pager();
 118                 break;
 119         default:
 120                 break;
 121         }
 122 }
 123
 124 void setup_auto_pager(const char *cmd, int def)
 125 {
 126         if (use_pager != -1 || pager_in_use())
 127                 return;
 128         use_pager = check_pager_config(cmd);
 129         if (use_pager == -1)
 130                 use_pager = def;
 131         commit_pager_choice();
 132 }
 133
 134 static int handle_options(const char ***argv, int *argc, int *envchanged)
 135 {
 136         const char **orig_argv = *argv;
 137
 138         while (*argc > 0) {
 139                 const char *cmd = (*argv)[0];
 140                 if (cmd[0] != '-')
 141                         break;
 142
 143                 /*
 144                  * For legacy reasons, the "version" and "help"
 145                  * commands can be written with "--" prepended
 146                  * to make them look like flags.
 147                  */
 148                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
 149                         break;
 150
 151                 /*
 152                  * Check remaining flags.
 153                  */
 154                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
 155                         if (*cmd == '=')
 156                                 git_set_exec_path(cmd + 1);
 157                         else {
 158                                 puts(git_exec_path());
 159                                 trace2_cmd_name("_query_");
 160                                 exit(0);
 161                         }
 162                 } else if (!strcmp(cmd, "--html-path")) {
 163                         puts(system_path(GIT_HTML_PATH));
 164                         trace2_cmd_name("_query_");
 165                         exit(0);
 166                 } else if (!strcmp(cmd, "--man-path")) {
 167                         puts(system_path(GIT_MAN_PATH));
 168                         trace2_cmd_name("_query_");
 169                         exit(0);
 170                 } else if (!strcmp(cmd, "--info-path")) {
 171                         puts(system_path(GIT_INFO_PATH));
 172                         trace2_cmd_name("_query_");
 173                         exit(0);
 174                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 175                         use_pager = 1;
 176                 } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
 177                         use_pager = 0;
 178                         if (envchanged)
 179                                 *envchanged = 1;
 180                 } else if (!strcmp(cmd, "--no-replace-objects")) {
 181                         read_replace_refs = 0;
 182                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 183                         if (envchanged)
 184                                 *envchanged = 1;
 185                 } else if (!strcmp(cmd, "--git-dir")) {
 186                         if (*argc < 2) {
 187                                 fprintf(stderr, _("no directory given for --git-dir\n" ));
 188                                 usage(git_usage_string);
 189                         }
 190                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 191                         if (envchanged)
 192                                 *envchanged = 1;
 193                         (*argv)++;
 194                         (*argc)--;
 195                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 196                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 197                         if (envchanged)
 198                                 *envchanged = 1;
 199                 } else if (!strcmp(cmd, "--namespace")) {
 200                         if (*argc < 2) {
 201                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 202                                 usage(git_usage_string);
 203                         }
 204                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 205                         if (envchanged)
 206                                 *envchanged = 1;
 207                         (*argv)++;
 208                         (*argc)--;
 209                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 210                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 211                         if (envchanged)
 212                                 *envchanged = 1;
 213                 } else if (!strcmp(cmd, "--work-tree")) {
 214                         if (*argc < 2) {
 215                                 fprintf(stderr, _("no directory given for --work-tree\n" ));
 216                                 usage(git_usage_string);
 217                         }
 218                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 219                         if (envchanged)
 220                                 *envchanged = 1;
 221                         (*argv)++;
 222                         (*argc)--;
 223                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 224                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 225                         if (envchanged)
 226                                 *envchanged = 1;
 227                 } else if (!strcmp(cmd, "--super-prefix")) {
 228                         if (*argc < 2) {
 229                                 fprintf(stderr, _("no prefix given for --super-prefix\n" ));
 230                                 usage(git_usage_string);
 231                         }
 232                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 233                         if (envchanged)
 234                                 *envchanged = 1;
 235                         (*argv)++;
 236                         (*argc)--;
 237                 } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 238                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 239                         if (envchanged)
 240                                 *envchanged = 1;
 241                 } else if (!strcmp(cmd, "--bare")) {
 242                         char *cwd = xgetcwd();
 243                         is_bare_repository_cfg = 1;
 244                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 245                         free(cwd);
 246                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 247                         if (envchanged)
 248                                 *envchanged = 1;
 249                 } else if (!strcmp(cmd, "-c")) {
 250                         if (*argc < 2) {
 251                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 252                                 usage(git_usage_string);
 253                         }
 254                         git_config_push_parameter((*argv)[1]);
 255                         (*argv)++;
 256                         (*argc)--;
 257                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 258                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 259                         if (envchanged)
 260                                 *envchanged = 1;
 261                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 262                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 263                         if (envchanged)
 264                                 *envchanged = 1;
 265                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
 266                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 267                         if (envchanged)
 268                                 *envchanged = 1;
 269                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 270                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 271                         if (envchanged)
 272                                 *envchanged = 1;
 273                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
 274                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 275                         if (envchanged)
 276                                 *envchanged = 1;
 277                 } else if (!strcmp(cmd, "--no-optional-locks")) {
 278                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 279                         if (envchanged)
 280                                 *envchanged = 1;
 281                 } else if (!strcmp(cmd, "--shallow-file")) {
 282                         (*argv)++;
 283                         (*argc)--;
 284                         set_alternate_shallow_file(the_repository, (*argv)[0], 1);
 285                         if (envchanged)
 286                                 *envchanged = 1;
 287                 } else if (!strcmp(cmd, "-C")) {
 288                         if (*argc < 2) {
 289                                 fprintf(stderr, _("no directory given for -C\n" ));
 290                                 usage(git_usage_string);
 291                         }
 292                         if ((*argv)[1][0]) {
 293                                 if (chdir((*argv)[1]))
 294                                         die_errno("cannot change to '%s'", (*argv)[1]);
 295                                 if (envchanged)
 296                                         *envchanged = 1;
 297                         }
 298                         (*argv)++;
 299                         (*argc)--;
 300                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 301                         trace2_cmd_name("_query_");
 302                         if (!strcmp(cmd, "parseopt")) {
 303                                 struct string_list list = STRING_LIST_INIT_DUP;
 304                                 int i;
 305
 306                                 list_builtins(&list, NO_PARSEOPT);
 307                                 for (i = 0; i < list.nr; i++)
 308                                         printf("%s ", list.items[i].string);
 309                                 string_list_clear(&list, 0);
 310                                 exit(0);
 311                         } else {
 312                                 exit(list_cmds(cmd));
 313                         }
 314                 } else {
 315                         fprintf(stderr, _("unknown option: %s\n"), cmd);
 316                         usage(git_usage_string);
 317                 }
 318
 319                 (*argv)++;
 320                 (*argc)--;
 321         }
 322         return (*argv) - orig_argv;
 323 }
 324
 325 static int handle_alias(int *argcp, const char ***argv)
 326 {
 327         int envchanged = 0, ret = 0, saved_errno = errno;
 328         int count, option_count;
 329         const char **new_argv;
 330         const char *alias_command;
 331         char *alias_string;
 332
 333         alias_command = (*argv)[0];
 334         alias_string = alias_lookup(alias_command);
 335         if (alias_string) {
 336                 if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
 337                         fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
 338                                    alias_command, alias_string);
 339                 if (alias_string[0] == '!') {
 340                         struct child_process child = CHILD_PROCESS_INIT;
 341                         int nongit_ok;
 342
 343                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 344                         setup_git_directory_gently(&nongit_ok);
 345
 346                         commit_pager_choice();
 347
 348                         child.use_shell = 1;
 349                         child.clean_on_exit = 1;
 350                         child.wait_after_clean = 1;
 351                         child.trace2_child_class = "shell_alias";
 352                         strvec_push(&child.args, alias_string + 1);
 353                         strvec_pushv(&child.args, (*argv) + 1);
 354
 355                         trace2_cmd_alias(alias_command, child.args.v);
 356                         trace2_cmd_list_config();
 357                         trace2_cmd_list_env_vars();
 358                         trace2_cmd_name("_run_shell_alias_");
 359
 360                         ret = run_command(&child);
 361                         if (ret >= 0)   /* normal exit */
 362                                 exit(ret);
 363
 364                         die_errno(_("while expanding alias '%s': '%s'"),
 365                                   alias_command, alias_string + 1);
 366                 }
 367                 count = split_cmdline(alias_string, &new_argv);
 368                 if (count < 0)
 369                         die(_("bad alias.%s string: %s"), alias_command,
 370                             _(split_cmdline_strerror(count)));
 371                 option_count = handle_options(&new_argv, &count, &envchanged);
 372                 if (envchanged)
 373                         die(_("alias '%s' changes environment variables.\n"
 374                               "You can use '!git' in the alias to do this"),
 375                             alias_command);
 376                 MOVE_ARRAY(new_argv - option_count, new_argv, count);
 377                 new_argv -= option_count;
 378
 379                 if (count < 1)
 380                         die(_("empty alias for %s"), alias_command);
 381
 382                 if (!strcmp(alias_command, new_argv[0]))
 383                         die(_("recursive alias: %s"), alias_command);
 384
 385                 trace_argv_printf(new_argv,
 386                                   "trace: alias expansion: %s =>",
 387                                   alias_command);
 388
 389                 REALLOC_ARRAY(new_argv, count + *argcp);
 390                 /* insert after command name */
 391                 COPY_ARRAY(new_argv + count, *argv + 1, *argcp);
 392
 393                 trace2_cmd_alias(alias_command, new_argv);
 394                 trace2_cmd_list_config();
 395                 trace2_cmd_list_env_vars();
 396
 397                 *argv = new_argv;
 398                 *argcp += count - 1;
 399
 400                 ret = 1;
 401         }
 402
 403         errno = saved_errno;
 404
 405         return ret;
 406 }
 407
 408 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 409 {
 410         int status, help;
 411         struct stat st;
 412         const char *prefix;
 413
 414         prefix = NULL;
 415         help = argc == 2 && !strcmp(argv[1], "-h");
 416         if (!help) {
 417                 if (p->option & RUN_SETUP)
 418                         prefix = setup_git_directory();
 419                 else if (p->option & RUN_SETUP_GENTLY) {
 420                         int nongit_ok;
 421                         prefix = setup_git_directory_gently(&nongit_ok);
 422                 }
 423
 424                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
 425                     !(p->option & DELAY_PAGER_CONFIG))
 426                         use_pager = check_pager_config(p->cmd);
 427                 if (use_pager == -1 && p->option & USE_PAGER)
 428                         use_pager = 1;
 429
 430                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 431                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 432                         trace_repo_setup(prefix);
 433         }
 434         commit_pager_choice();
 435
 436         if (!help && get_super_prefix()) {
 437                 if (!(p->option & SUPPORT_SUPER_PREFIX))
 438                         die(_("%s doesn't support --super-prefix"), p->cmd);
 439         }
 440
 441         if (!help && p->option & NEED_WORK_TREE)
 442                 setup_work_tree();
 443
 444         trace_argv_printf(argv, "trace: built-in: git");
 445         trace2_cmd_name(p->cmd);
 446         trace2_cmd_list_config();
 447         trace2_cmd_list_env_vars();
 448
 449         validate_cache_entries(the_repository->index);
 450         status = p->fn(argc, argv, prefix);
 451         validate_cache_entries(the_repository->index);
 452
 453         if (status)
 454                 return status;
 455
 456         /* Somebody closed stdout? */
 457         if (fstat(fileno(stdout), &st))
 458                 return 0;
 459         /* Ignore write errors for pipes and sockets.. */
 460         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 461                 return 0;
 462
 463         /* Check for ENOSPC and EIO errors.. */
 464         if (fflush(stdout))
 465                 die_errno(_("write failure on standard output"));
 466         if (ferror(stdout))
 467                 die(_("unknown write failure on standard output"));
 468         if (fclose(stdout))
 469                 die_errno(_("close failed on standard output"));
 470         return 0;
 471 }
 472
 473 static struct cmd_struct commands[] = {
 474         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 475         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 476         { "annotate", cmd_annotate, RUN_SETUP | NO_PARSEOPT },
 477         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 478         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 479         { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 480         { "blame", cmd_blame, RUN_SETUP },
 481         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 482         { "bugreport", cmd_bugreport, RUN_SETUP_GENTLY },
 483         { "bundle", cmd_bundle, RUN_SETUP_GENTLY | NO_PARSEOPT },
 484         { "cat-file", cmd_cat_file, RUN_SETUP },
 485         { "check-attr", cmd_check_attr, RUN_SETUP },
 486         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 487         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 488         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 489         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 490         { "checkout-index", cmd_checkout_index,
 491                 RUN_SETUP | NEED_WORK_TREE},
 492         { "cherry", cmd_cherry, RUN_SETUP },
 493         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 494         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 495         { "clone", cmd_clone },
 496         { "column", cmd_column, RUN_SETUP_GENTLY },
 497         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 498         { "commit-graph", cmd_commit_graph, RUN_SETUP },
 499         { "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
 500         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 501         { "count-objects", cmd_count_objects, RUN_SETUP },
 502         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 503         { "credential-cache", cmd_credential_cache },
 504         { "credential-cache--daemon", cmd_credential_cache_daemon },
 505         { "credential-store", cmd_credential_store },
 506         { "describe", cmd_describe, RUN_SETUP },
 507         { "diff", cmd_diff, NO_PARSEOPT },
 508         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 509         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 510         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 511         { "difftool", cmd_difftool, RUN_SETUP_GENTLY },
 512         { "env--helper", cmd_env__helper },
 513         { "fast-export", cmd_fast_export, RUN_SETUP },
 514         { "fast-import", cmd_fast_import, RUN_SETUP | NO_PARSEOPT },
 515         { "fetch", cmd_fetch, RUN_SETUP },
 516         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 517         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 518         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 519         { "for-each-repo", cmd_for_each_repo, RUN_SETUP_GENTLY },
 520         { "format-patch", cmd_format_patch, RUN_SETUP },
 521         { "fsck", cmd_fsck, RUN_SETUP },
 522         { "fsck-objects", cmd_fsck, RUN_SETUP },
 523         { "gc", cmd_gc, RUN_SETUP },
 524         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 525         { "grep", cmd_grep, RUN_SETUP_GENTLY },
 526         { "hash-object", cmd_hash_object },
 527         { "help", cmd_help },
 528         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 529         { "init", cmd_init_db },
 530         { "init-db", cmd_init_db },
 531         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 532         { "log", cmd_log, RUN_SETUP },
 533         { "ls-files", cmd_ls_files, RUN_SETUP },
 534         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 535         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 536         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY | NO_PARSEOPT },
 537         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 538         { "maintenance", cmd_maintenance, RUN_SETUP | NO_PARSEOPT },
 539         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 540         { "merge-base", cmd_merge_base, RUN_SETUP },
 541         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 542         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 543         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 544         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 545         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 546         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 547         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 548         { "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
 549         { "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
 550         { "mktree", cmd_mktree, RUN_SETUP },
 551         { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP_GENTLY },
 552         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 553         { "name-rev", cmd_name_rev, RUN_SETUP },
 554         { "notes", cmd_notes, RUN_SETUP },
 555         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 556         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 557         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 558         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 559         { "pickaxe", cmd_blame, RUN_SETUP },
 560         { "prune", cmd_prune, RUN_SETUP },
 561         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 562         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 563         { "push", cmd_push, RUN_SETUP },
 564         { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
 565         { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 566         { "rebase", cmd_rebase, RUN_SETUP | NEED_WORK_TREE },
 567         { "rebase--interactive", cmd_rebase__interactive, RUN_SETUP | NEED_WORK_TREE },
 568         { "receive-pack", cmd_receive_pack },
 569         { "reflog", cmd_reflog, RUN_SETUP },
 570         { "remote", cmd_remote, RUN_SETUP },
 571         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 572         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 573         { "repack", cmd_repack, RUN_SETUP },
 574         { "replace", cmd_replace, RUN_SETUP },
 575         { "rerere", cmd_rerere, RUN_SETUP },
 576         { "reset", cmd_reset, RUN_SETUP },
 577         { "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
 578         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 579         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 580         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 581         { "rm", cmd_rm, RUN_SETUP },
 582         { "send-pack", cmd_send_pack, RUN_SETUP },
 583         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 584         { "show", cmd_show, RUN_SETUP },
 585         { "show-branch", cmd_show_branch, RUN_SETUP },
 586         { "show-index", cmd_show_index, RUN_SETUP_GENTLY },
 587         { "show-ref", cmd_show_ref, RUN_SETUP },
 588         { "sparse-checkout", cmd_sparse_checkout, RUN_SETUP | NEED_WORK_TREE },
 589         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 590         { "stash", cmd_stash, RUN_SETUP | NEED_WORK_TREE },
 591         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 592         { "stripspace", cmd_stripspace },
 593         { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
 594         { "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
 595         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 596         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 597         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 598         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 599         { "update-index", cmd_update_index, RUN_SETUP },
 600         { "update-ref", cmd_update_ref, RUN_SETUP },
 601         { "update-server-info", cmd_update_server_info, RUN_SETUP },
 602         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 603         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 604         { "upload-pack", cmd_upload_pack },
 605         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 606         { "verify-commit", cmd_verify_commit, RUN_SETUP },
 607         { "verify-pack", cmd_verify_pack },
 608         { "verify-tag", cmd_verify_tag, RUN_SETUP },
 609         { "version", cmd_version },
 610         { "whatchanged", cmd_whatchanged, RUN_SETUP },
 611         { "worktree", cmd_worktree, RUN_SETUP | NO_PARSEOPT },
 612         { "write-tree", cmd_write_tree, RUN_SETUP },
 613 };
 614
 615 static struct cmd_struct *get_builtin(const char *s)
 616 {
 617         int i;
 618         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 619                 struct cmd_struct *p = commands + i;
 620                 if (!strcmp(s, p->cmd))
 621                         return p;
 622         }
 623         return NULL;
 624 }
 625
 626 int is_builtin(const char *s)
 627 {
 628         return !!get_builtin(s);
 629 }
 630
 631 static void list_builtins(struct string_list *out, unsigned int exclude_option)
 632 {
 633         int i;
 634         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 635                 if (exclude_option &&
 636                     (commands[i].option & exclude_option))
 637                         continue;
 638                 string_list_append(out, commands[i].cmd);
 639         }
 640 }
 641
 642 void load_builtin_commands(const char *prefix, struct cmdnames *cmds)
 643 {
 644         const char *name;
 645         int i;
 646
 647         /*
 648          * Callers can ask for a subset of the commands based on a certain
 649          * prefix, which is then dropped from the added names. The names in
 650          * the `commands[]` array do not have the `git-` prefix, though,
 651          * therefore we must expect the `prefix` to at least start with `git-`.
 652          */
 653         if (!skip_prefix(prefix, "git-", &prefix))
 654                 BUG("prefix '%s' must start with 'git-'", prefix);
 655
 656         for (i = 0; i < ARRAY_SIZE(commands); i++)
 657                 if (skip_prefix(commands[i].cmd, prefix, &name))
 658                         add_cmdname(cmds, name, strlen(name));
 659 }
 660
 661 #ifdef STRIP_EXTENSION
 662 static void strip_extension(const char **argv)
 663 {
 664         size_t len;
 665
 666         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 667                 argv[0] = xmemdupz(argv[0], len);
 668 }
 669 #else
 670 #define strip_extension(cmd)
 671 #endif
 672
 673 static void handle_builtin(int argc, const char **argv)
 674 {
 675         struct strvec args = STRVEC_INIT;
 676         const char *cmd;
 677         struct cmd_struct *builtin;
 678
 679         strip_extension(argv);
 680         cmd = argv[0];
 681
 682         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 683         if (argc > 1 && !strcmp(argv[1], "--help")) {
 684                 int i;
 685
 686                 argv[1] = argv[0];
 687                 argv[0] = cmd = "help";
 688
 689                 for (i = 0; i < argc; i++) {
 690                         strvec_push(&args, argv[i]);
 691                         if (!i)
 692                                 strvec_push(&args, "--exclude-guides");
 693                 }
 694
 695                 argc++;
 696                 argv = args.v;
 697         }
 698
 699         builtin = get_builtin(cmd);
 700         if (builtin)
 701                 exit(run_builtin(builtin, argc, argv));
 702         strvec_clear(&args);
 703 }
 704
 705 static void execv_dashed_external(const char **argv)
 706 {
 707         struct child_process cmd = CHILD_PROCESS_INIT;
 708         int status;
 709
 710         if (get_super_prefix())
 711                 die(_("%s doesn't support --super-prefix"), argv[0]);
 712
 713         if (use_pager == -1 && !is_builtin(argv[0]))
 714                 use_pager = check_pager_config(argv[0]);
 715         commit_pager_choice();
 716
 717         strvec_pushf(&cmd.args, "git-%s", argv[0]);
 718         strvec_pushv(&cmd.args, argv + 1);
 719         cmd.clean_on_exit = 1;
 720         cmd.wait_after_clean = 1;
 721         cmd.silent_exec_failure = 1;
 722         cmd.trace2_child_class = "dashed";
 723
 724         trace2_cmd_name("_run_dashed_");
 725
 726         /*
 727          * The code in run_command() logs trace2 child_start/child_exit
 728          * events, so we do not need to report exec/exec_result events here.
 729          */
 730         trace_argv_printf(cmd.args.v, "trace: exec:");
 731
 732         /*
 733          * If we fail because the command is not found, it is
 734          * OK to return. Otherwise, we just pass along the status code,
 735          * or our usual generic code if we were not even able to exec
 736          * the program.
 737          */
 738         status = run_command(&cmd);
 739
 740         /*
 741          * If the child process ran and we are now going to exit, emit a
 742          * generic string as our trace2 command verb to indicate that we
 743          * launched a dashed command.
 744          */
 745         if (status >= 0)
 746                 exit(status);
 747         else if (errno != ENOENT)
 748                 exit(128);
 749 }
 750
 751 static int run_argv(int *argcp, const char ***argv)
 752 {
 753         int done_alias = 0;
 754         struct string_list cmd_list = STRING_LIST_INIT_NODUP;
 755         struct string_list_item *seen;
 756
 757         while (1) {
 758                 /*
 759                  * If we tried alias and futzed with our environment,
 760                  * it no longer is safe to invoke builtins directly in
 761                  * general.  We have to spawn them as dashed externals.
 762                  *
 763                  * NEEDSWORK: if we can figure out cases
 764                  * where it is safe to do, we can avoid spawning a new
 765                  * process.
 766                  */
 767                 if (!done_alias)
 768                         handle_builtin(*argcp, *argv);
 769                 else if (get_builtin(**argv)) {
 770                         struct strvec args = STRVEC_INIT;
 771                         int i;
 772
 773                         /*
 774                          * The current process is committed to launching a
 775                          * child process to run the command named in (**argv)
 776                          * and exiting.  Log a generic string as the trace2
 777                          * command verb to indicate this.  Note that the child
 778                          * process will log the actual verb when it runs.
 779                          */
 780                         trace2_cmd_name("_run_git_alias_");
 781
 782                         if (get_super_prefix())
 783                                 die("%s doesn't support --super-prefix", **argv);
 784
 785                         commit_pager_choice();
 786
 787                         strvec_push(&args, "git");
 788                         for (i = 0; i < *argcp; i++)
 789                                 strvec_push(&args, (*argv)[i]);
 790
 791                         trace_argv_printf(args.v, "trace: exec:");
 792
 793                         /*
 794                          * if we fail because the command is not found, it is
 795                          * OK to return. Otherwise, we just pass along the status code.
 796                          */
 797                         i = run_command_v_opt_tr2(args.v, RUN_SILENT_EXEC_FAILURE |
 798                                                   RUN_CLEAN_ON_EXIT | RUN_WAIT_AFTER_CLEAN, "git_alias");
 799                         if (i >= 0 || errno != ENOENT)
 800                                 exit(i);
 801                         die("could not execute builtin %s", **argv);
 802                 }
 803
 804                 /* .. then try the external ones */
 805                 execv_dashed_external(*argv);
 806
 807                 seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
 808                 if (seen) {
 809                         int i;
 810                         struct strbuf sb = STRBUF_INIT;
 811                         for (i = 0; i < cmd_list.nr; i++) {
 812                                 struct string_list_item *item = &cmd_list.items[i];
 813
 814                                 strbuf_addf(&sb, "\n  %s", item->string);
 815                                 if (item == seen)
 816                                         strbuf_addstr(&sb, " <==");
 817                                 else if (i == cmd_list.nr - 1)
 818                                         strbuf_addstr(&sb, " ==>");
 819                         }
 820                         die(_("alias loop detected: expansion of '%s' does"
 821                               " not terminate:%s"), cmd_list.items[0].string, sb.buf);
 822                 }
 823
 824                 string_list_append(&cmd_list, *argv[0]);
 825
 826                 /*
 827                  * It could be an alias -- this works around the insanity
 828                  * of overriding "git log" with "git show" by having
 829                  * alias.log = show
 830                  */
 831                 if (!handle_alias(argcp, argv))
 832                         break;
 833                 done_alias = 1;
 834         }
 835
 836         string_list_clear(&cmd_list, 0);
 837
 838         return done_alias;
 839 }
 840
 841 int cmd_main(int argc, const char **argv)
 842 {
 843         const char *cmd;
 844         int done_help = 0;
 845
 846         cmd = argv[0];
 847         if (!cmd)
 848                 cmd = "git-help";
 849         else {
 850                 const char *slash = find_last_dir_sep(cmd);
 851                 if (slash)
 852                         cmd = slash + 1;
 853         }
 854
 855         trace_command_performance(argv);
 856
 857         /*
 858          * "git-xxxx" is the same as "git xxxx", but we obviously:
 859          *
 860          *  - cannot take flags in between the "git" and the "xxxx".
 861          *  - cannot execute it externally (since it would just do
 862          *    the same thing over again)
 863          *
 864          * So we just directly call the builtin handler, and die if
 865          * that one cannot handle it.
 866          */
 867         if (skip_prefix(cmd, "git-", &cmd)) {
 868                 argv[0] = cmd;
 869                 handle_builtin(argc, argv);
 870                 die(_("cannot handle %s as a builtin"), cmd);
 871         }
 872
 873         /* Look for flags.. */
 874         argv++;
 875         argc--;
 876         handle_options(&argv, &argc, NULL);
 877         if (argc > 0) {
 878                 /* translate --help and --version into commands */
 879                 skip_prefix(argv[0], "--", &argv[0]);
 880         } else {
 881                 /* The user didn't specify a command; give them help */
 882                 commit_pager_choice();
 883                 printf(_("usage: %s\n\n"), git_usage_string);
 884                 list_common_cmds_help();
 885                 printf("\n%s\n", _(git_more_info_string));
 886                 exit(1);
 887         }
 888         cmd = argv[0];
 889
 890         /*
 891          * We use PATH to find git commands, but we prepend some higher
 892          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 893          * environment, and the $(gitexecdir) from the Makefile at build
 894          * time.
 895          */
 896         setup_path();
 897
 898         while (1) {
 899                 int was_alias = run_argv(&argc, &argv);
 900                 if (errno != ENOENT)
 901                         break;
 902                 if (was_alias) {
 903                         fprintf(stderr, _("expansion of alias '%s' failed; "
 904                                           "'%s' is not a git command\n"),
 905                                 cmd, argv[0]);
 906                         exit(1);
 907                 }
 908                 if (!done_help) {
 909                         cmd = argv[0] = help_unknown_cmd(cmd);
 910                         done_help = 1;
 911                 } else
 912                         break;
 913         }
 914
 915         fprintf(stderr, _("failed to run command '%s': %s\n"),
 916                 cmd, strerror(errno));
 917
 918         return 1;
 919 }