git.c

   1 #include "builtin.h"
   2 #include "config.h"
   3 #include "exec-cmd.h"
   4 #include "gettext.h"
   5 #include "help.h"
   6 #include "run-command.h"
   7 #include "alias.h"
   8 #include "replace-object.h"
   9 #include "shallow.h"
  10
  11 #define RUN_SETUP               (1<<0)
  12 #define RUN_SETUP_GENTLY        (1<<1)
  13 #define USE_PAGER               (1<<2)
  14 /*
  15  * require working tree to be present -- anything uses this needs
  16  * RUN_SETUP for reading from the configuration file.
  17  */
  18 #define NEED_WORK_TREE          (1<<3)
  19 #define DELAY_PAGER_CONFIG      (1<<4)
  20 #define NO_PARSEOPT             (1<<5) /* parse-options is not used */
  21
  22 struct cmd_struct {
  23         const char *cmd;
  24         int (*fn)(int, const char **, const char *);
  25         unsigned int option;
  26 };
  27
  28 const char git_usage_string[] =
  29         N_("git [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]\n"
  30            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  31            "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
  32            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  33            "           [--config-env=<name>=<envvar>] <command> [<args>]");
  34
  35 const char git_more_info_string[] =
  36         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  37            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  38            "to read about a specific subcommand or concept.\n"
  39            "See 'git help git' for an overview of the system.");
  40
  41 static int use_pager = -1;
  42
  43 static void list_builtins(struct string_list *list, unsigned int exclude_option);
  44
  45 static void exclude_helpers_from_list(struct string_list *list)
  46 {
  47         int i = 0;
  48
  49         while (i < list->nr) {
  50                 if (strstr(list->items[i].string, "--"))
  51                         unsorted_string_list_delete_item(list, i, 0);
  52                 else
  53                         i++;
  54         }
  55 }
  56
  57 static int match_token(const char *spec, int len, const char *token)
  58 {
  59         int token_len = strlen(token);
  60
  61         return len == token_len && !strncmp(spec, token, token_len);
  62 }
  63
  64 static int list_cmds(const char *spec)
  65 {
  66         struct string_list list = STRING_LIST_INIT_DUP;
  67         int i;
  68         int nongit;
  69
  70         /*
  71         * Set up the repository so we can pick up any repo-level config (like
  72         * completion.commands).
  73         */
  74         setup_git_directory_gently(&nongit);
  75
  76         while (*spec) {
  77                 const char *sep = strchrnul(spec, ',');
  78                 int len = sep - spec;
  79
  80                 if (match_token(spec, len, "builtins"))
  81                         list_builtins(&list, 0);
  82                 else if (match_token(spec, len, "main"))
  83                         list_all_main_cmds(&list);
  84                 else if (match_token(spec, len, "others"))
  85                         list_all_other_cmds(&list);
  86                 else if (match_token(spec, len, "nohelpers"))
  87                         exclude_helpers_from_list(&list);
  88                 else if (match_token(spec, len, "alias"))
  89                         list_aliases(&list);
  90                 else if (match_token(spec, len, "config"))
  91                         list_cmds_by_config(&list);
  92                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
  93                         struct strbuf sb = STRBUF_INIT;
  94
  95                         strbuf_add(&sb, spec + 5, len - 5);
  96                         list_cmds_by_category(&list, sb.buf);
  97                         strbuf_release(&sb);
  98                 }
  99                 else
 100                         die(_("unsupported command listing type '%s'"), spec);
 101                 spec += len;
 102                 if (*spec == ',')
 103                         spec++;
 104         }
 105         for (i = 0; i < list.nr; i++)
 106                 puts(list.items[i].string);
 107         string_list_clear(&list, 0);
 108         return 0;
 109 }
 110
 111 static void commit_pager_choice(void)
 112 {
 113         switch (use_pager) {
 114         case 0:
 115                 setenv("GIT_PAGER", "cat", 1);
 116                 break;
 117         case 1:
 118                 setup_pager();
 119                 break;
 120         default:
 121                 break;
 122         }
 123 }
 124
 125 void setup_auto_pager(const char *cmd, int def)
 126 {
 127         if (use_pager != -1 || pager_in_use())
 128                 return;
 129         use_pager = check_pager_config(cmd);
 130         if (use_pager == -1)
 131                 use_pager = def;
 132         commit_pager_choice();
 133 }
 134
 135 static int handle_options(const char ***argv, int *argc, int *envchanged)
 136 {
 137         const char **orig_argv = *argv;
 138
 139         while (*argc > 0) {
 140                 const char *cmd = (*argv)[0];
 141                 if (cmd[0] != '-')
 142                         break;
 143
 144                 /*
 145                  * For legacy reasons, the "version" and "help"
 146                  * commands can be written with "--" prepended
 147                  * to make them look like flags.
 148                  */
 149                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h") ||
 150                     !strcmp(cmd, "--version") || !strcmp(cmd, "-v"))
 151                         break;
 152
 153                 /*
 154                  * Check remaining flags.
 155                  */
 156                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
 157                         if (*cmd == '=')
 158                                 git_set_exec_path(cmd + 1);
 159                         else {
 160                                 puts(git_exec_path());
 161                                 trace2_cmd_name("_query_");
 162                                 exit(0);
 163                         }
 164                 } else if (!strcmp(cmd, "--html-path")) {
 165                         puts(system_path(GIT_HTML_PATH));
 166                         trace2_cmd_name("_query_");
 167                         exit(0);
 168                 } else if (!strcmp(cmd, "--man-path")) {
 169                         puts(system_path(GIT_MAN_PATH));
 170                         trace2_cmd_name("_query_");
 171                         exit(0);
 172                 } else if (!strcmp(cmd, "--info-path")) {
 173                         puts(system_path(GIT_INFO_PATH));
 174                         trace2_cmd_name("_query_");
 175                         exit(0);
 176                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 177                         use_pager = 1;
 178                 } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
 179                         use_pager = 0;
 180                         if (envchanged)
 181                                 *envchanged = 1;
 182                 } else if (!strcmp(cmd, "--no-replace-objects")) {
 183                         read_replace_refs = 0;
 184                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 185                         if (envchanged)
 186                                 *envchanged = 1;
 187                 } else if (!strcmp(cmd, "--git-dir")) {
 188                         if (*argc < 2) {
 189                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--git-dir");
 190                                 usage(git_usage_string);
 191                         }
 192                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 193                         if (envchanged)
 194                                 *envchanged = 1;
 195                         (*argv)++;
 196                         (*argc)--;
 197                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 198                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 199                         if (envchanged)
 200                                 *envchanged = 1;
 201                 } else if (!strcmp(cmd, "--namespace")) {
 202                         if (*argc < 2) {
 203                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 204                                 usage(git_usage_string);
 205                         }
 206                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 207                         if (envchanged)
 208                                 *envchanged = 1;
 209                         (*argv)++;
 210                         (*argc)--;
 211                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 212                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 213                         if (envchanged)
 214                                 *envchanged = 1;
 215                 } else if (!strcmp(cmd, "--work-tree")) {
 216                         if (*argc < 2) {
 217                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--work-tree");
 218                                 usage(git_usage_string);
 219                         }
 220                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 221                         if (envchanged)
 222                                 *envchanged = 1;
 223                         (*argv)++;
 224                         (*argc)--;
 225                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 226                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 227                         if (envchanged)
 228                                 *envchanged = 1;
 229                 } else if (!strcmp(cmd, "--bare")) {
 230                         char *cwd = xgetcwd();
 231                         is_bare_repository_cfg = 1;
 232                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 233                         free(cwd);
 234                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 235                         if (envchanged)
 236                                 *envchanged = 1;
 237                 } else if (!strcmp(cmd, "-c")) {
 238                         if (*argc < 2) {
 239                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 240                                 usage(git_usage_string);
 241                         }
 242                         git_config_push_parameter((*argv)[1]);
 243                         (*argv)++;
 244                         (*argc)--;
 245                 } else if (!strcmp(cmd, "--config-env")) {
 246                         if (*argc < 2) {
 247                                 fprintf(stderr, _("no config key given for --config-env\n" ));
 248                                 usage(git_usage_string);
 249                         }
 250                         git_config_push_env((*argv)[1]);
 251                         (*argv)++;
 252                         (*argc)--;
 253                 } else if (skip_prefix(cmd, "--config-env=", &cmd)) {
 254                         git_config_push_env(cmd);
 255                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 256                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 257                         if (envchanged)
 258                                 *envchanged = 1;
 259                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 260                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 261                         if (envchanged)
 262                                 *envchanged = 1;
 263                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
 264                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 265                         if (envchanged)
 266                                 *envchanged = 1;
 267                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 268                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 269                         if (envchanged)
 270                                 *envchanged = 1;
 271                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
 272                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 273                         if (envchanged)
 274                                 *envchanged = 1;
 275                 } else if (!strcmp(cmd, "--no-optional-locks")) {
 276                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 277                         if (envchanged)
 278                                 *envchanged = 1;
 279                 } else if (!strcmp(cmd, "--shallow-file")) {
 280                         (*argv)++;
 281                         (*argc)--;
 282                         set_alternate_shallow_file(the_repository, (*argv)[0], 1);
 283                         if (envchanged)
 284                                 *envchanged = 1;
 285                 } else if (!strcmp(cmd, "-C")) {
 286                         if (*argc < 2) {
 287                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "-C");
 288                                 usage(git_usage_string);
 289                         }
 290                         if ((*argv)[1][0]) {
 291                                 if (chdir((*argv)[1]))
 292                                         die_errno("cannot change to '%s'", (*argv)[1]);
 293                                 if (envchanged)
 294                                         *envchanged = 1;
 295                         }
 296                         (*argv)++;
 297                         (*argc)--;
 298                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 299                         trace2_cmd_name("_query_");
 300                         if (!strcmp(cmd, "parseopt")) {
 301                                 struct string_list list = STRING_LIST_INIT_DUP;
 302                                 int i;
 303
 304                                 list_builtins(&list, NO_PARSEOPT);
 305                                 for (i = 0; i < list.nr; i++)
 306                                         printf("%s ", list.items[i].string);
 307                                 string_list_clear(&list, 0);
 308                                 exit(0);
 309                         } else {
 310                                 exit(list_cmds(cmd));
 311                         }
 312                 } else {
 313                         fprintf(stderr, _("unknown option: %s\n"), cmd);
 314                         usage(git_usage_string);
 315                 }
 316
 317                 (*argv)++;
 318                 (*argc)--;
 319         }
 320         return (*argv) - orig_argv;
 321 }
 322
 323 static int handle_alias(int *argcp, const char ***argv)
 324 {
 325         int envchanged = 0, ret = 0, saved_errno = errno;
 326         int count, option_count;
 327         const char **new_argv;
 328         const char *alias_command;
 329         char *alias_string;
 330
 331         alias_command = (*argv)[0];
 332         alias_string = alias_lookup(alias_command);
 333         if (alias_string) {
 334                 if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
 335                         fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
 336                                    alias_command, alias_string);
 337                 if (alias_string[0] == '!') {
 338                         struct child_process child = CHILD_PROCESS_INIT;
 339                         int nongit_ok;
 340
 341                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 342                         setup_git_directory_gently(&nongit_ok);
 343
 344                         commit_pager_choice();
 345
 346                         child.use_shell = 1;
 347                         child.clean_on_exit = 1;
 348                         child.wait_after_clean = 1;
 349                         child.trace2_child_class = "shell_alias";
 350                         strvec_push(&child.args, alias_string + 1);
 351                         strvec_pushv(&child.args, (*argv) + 1);
 352
 353                         trace2_cmd_alias(alias_command, child.args.v);
 354                         trace2_cmd_list_config();
 355                         trace2_cmd_list_env_vars();
 356                         trace2_cmd_name("_run_shell_alias_");
 357
 358                         ret = run_command(&child);
 359                         if (ret >= 0)   /* normal exit */
 360                                 exit(ret);
 361
 362                         die_errno(_("while expanding alias '%s': '%s'"),
 363                                   alias_command, alias_string + 1);
 364                 }
 365                 count = split_cmdline(alias_string, &new_argv);
 366                 if (count < 0)
 367                         die(_("bad alias.%s string: %s"), alias_command,
 368                             _(split_cmdline_strerror(count)));
 369                 option_count = handle_options(&new_argv, &count, &envchanged);
 370                 if (envchanged)
 371                         die(_("alias '%s' changes environment variables.\n"
 372                               "You can use '!git' in the alias to do this"),
 373                             alias_command);
 374                 MOVE_ARRAY(new_argv - option_count, new_argv, count);
 375                 new_argv -= option_count;
 376
 377                 if (count < 1)
 378                         die(_("empty alias for %s"), alias_command);
 379
 380                 if (!strcmp(alias_command, new_argv[0]))
 381                         die(_("recursive alias: %s"), alias_command);
 382
 383                 trace_argv_printf(new_argv,
 384                                   "trace: alias expansion: %s =>",
 385                                   alias_command);
 386
 387                 REALLOC_ARRAY(new_argv, count + *argcp);
 388                 /* insert after command name */
 389                 COPY_ARRAY(new_argv + count, *argv + 1, *argcp);
 390
 391                 trace2_cmd_alias(alias_command, new_argv);
 392                 trace2_cmd_list_config();
 393                 trace2_cmd_list_env_vars();
 394
 395                 *argv = new_argv;
 396                 *argcp += count - 1;
 397
 398                 ret = 1;
 399         }
 400
 401         errno = saved_errno;
 402
 403         return ret;
 404 }
 405
 406 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 407 {
 408         int status, help;
 409         struct stat st;
 410         const char *prefix;
 411         int run_setup = (p->option & (RUN_SETUP | RUN_SETUP_GENTLY));
 412
 413         help = argc == 2 && !strcmp(argv[1], "-h");
 414         if (help && (run_setup & RUN_SETUP))
 415                 /* demote to GENTLY to allow 'git cmd -h' outside repo */
 416                 run_setup = RUN_SETUP_GENTLY;
 417
 418         if (run_setup & RUN_SETUP) {
 419                 prefix = setup_git_directory();
 420         } else if (run_setup & RUN_SETUP_GENTLY) {
 421                 int nongit_ok;
 422                 prefix = setup_git_directory_gently(&nongit_ok);
 423         } else {
 424                 prefix = NULL;
 425         }
 426         assert(!prefix || *prefix);
 427         precompose_argv_prefix(argc, argv, NULL);
 428         if (use_pager == -1 && run_setup &&
 429                 !(p->option & DELAY_PAGER_CONFIG))
 430                 use_pager = check_pager_config(p->cmd);
 431         if (use_pager == -1 && p->option & USE_PAGER)
 432                 use_pager = 1;
 433         if (run_setup && startup_info->have_repository)
 434                 /* get_git_dir() may set up repo, avoid that */
 435                 trace_repo_setup();
 436         commit_pager_choice();
 437
 438         if (!help && p->option & NEED_WORK_TREE)
 439                 setup_work_tree();
 440
 441         trace_argv_printf(argv, "trace: built-in: git");
 442         trace2_cmd_name(p->cmd);
 443         trace2_cmd_list_config();
 444         trace2_cmd_list_env_vars();
 445
 446         validate_cache_entries(the_repository->index);
 447         status = p->fn(argc, argv, prefix);
 448         validate_cache_entries(the_repository->index);
 449
 450         if (status)
 451                 return status;
 452
 453         /* Somebody closed stdout? */
 454         if (fstat(fileno(stdout), &st))
 455                 return 0;
 456         /* Ignore write errors for pipes and sockets.. */
 457         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 458                 return 0;
 459
 460         /* Check for ENOSPC and EIO errors.. */
 461         if (fflush(stdout))
 462                 die_errno(_("write failure on standard output"));
 463         if (ferror(stdout))
 464                 die(_("unknown write failure on standard output"));
 465         if (fclose(stdout))
 466                 die_errno(_("close failed on standard output"));
 467         return 0;
 468 }
 469
 470 static struct cmd_struct commands[] = {
 471         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 472         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 473         { "annotate", cmd_annotate, RUN_SETUP },
 474         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 475         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 476         { "bisect", cmd_bisect, RUN_SETUP },
 477         { "blame", cmd_blame, RUN_SETUP },
 478         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 479         { "bugreport", cmd_bugreport, RUN_SETUP_GENTLY },
 480         { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 481         { "cat-file", cmd_cat_file, RUN_SETUP },
 482         { "check-attr", cmd_check_attr, RUN_SETUP },
 483         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 484         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 485         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 486         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 487         { "checkout--worker", cmd_checkout__worker,
 488                 RUN_SETUP | NEED_WORK_TREE },
 489         { "checkout-index", cmd_checkout_index,
 490                 RUN_SETUP | NEED_WORK_TREE},
 491         { "cherry", cmd_cherry, RUN_SETUP },
 492         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 493         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 494         { "clone", cmd_clone },
 495         { "column", cmd_column, RUN_SETUP_GENTLY },
 496         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 497         { "commit-graph", cmd_commit_graph, RUN_SETUP },
 498         { "commit-tree", cmd_commit_tree, RUN_SETUP },
 499         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 500         { "count-objects", cmd_count_objects, RUN_SETUP },
 501         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 502         { "credential-cache", cmd_credential_cache },
 503         { "credential-cache--daemon", cmd_credential_cache_daemon },
 504         { "credential-store", cmd_credential_store },
 505         { "describe", cmd_describe, RUN_SETUP },
 506         { "diagnose", cmd_diagnose, RUN_SETUP_GENTLY },
 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         { "fast-export", cmd_fast_export, RUN_SETUP },
 513         { "fast-import", cmd_fast_import, RUN_SETUP | NO_PARSEOPT },
 514         { "fetch", cmd_fetch, RUN_SETUP },
 515         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 516         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 517         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 518         { "for-each-repo", cmd_for_each_repo, RUN_SETUP_GENTLY },
 519         { "format-patch", cmd_format_patch, RUN_SETUP },
 520         { "fsck", cmd_fsck, RUN_SETUP },
 521         { "fsck-objects", cmd_fsck, RUN_SETUP },
 522         { "fsmonitor--daemon", cmd_fsmonitor__daemon, 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         { "hook", cmd_hook, RUN_SETUP },
 529         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 530         { "init", cmd_init_db },
 531         { "init-db", cmd_init_db },
 532         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 533         { "log", cmd_log, RUN_SETUP },
 534         { "ls-files", cmd_ls_files, RUN_SETUP },
 535         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 536         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 537         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
 538         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 539         { "maintenance", cmd_maintenance, RUN_SETUP },
 540         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 541         { "merge-base", cmd_merge_base, RUN_SETUP },
 542         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 543         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 544         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 545         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 546         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 547         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 548         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 549         { "merge-tree", cmd_merge_tree, RUN_SETUP },
 550         { "mktag", cmd_mktag, RUN_SETUP },
 551         { "mktree", cmd_mktree, RUN_SETUP },
 552         { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP },
 553         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 554         { "name-rev", cmd_name_rev, RUN_SETUP },
 555         { "notes", cmd_notes, RUN_SETUP },
 556         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 557         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 558         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 559         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 560         { "pickaxe", cmd_blame, RUN_SETUP },
 561         { "prune", cmd_prune, RUN_SETUP },
 562         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 563         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 564         { "push", cmd_push, RUN_SETUP },
 565         { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
 566         { "read-tree", cmd_read_tree, RUN_SETUP },
 567         { "rebase", cmd_rebase, 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 },
 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 },
 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 (use_pager == -1 && !is_builtin(argv[0]))
 711                 use_pager = check_pager_config(argv[0]);
 712         commit_pager_choice();
 713
 714         strvec_pushf(&cmd.args, "git-%s", argv[0]);
 715         strvec_pushv(&cmd.args, argv + 1);
 716         cmd.clean_on_exit = 1;
 717         cmd.wait_after_clean = 1;
 718         cmd.silent_exec_failure = 1;
 719         cmd.trace2_child_class = "dashed";
 720
 721         trace2_cmd_name("_run_dashed_");
 722
 723         /*
 724          * The code in run_command() logs trace2 child_start/child_exit
 725          * events, so we do not need to report exec/exec_result events here.
 726          */
 727         trace_argv_printf(cmd.args.v, "trace: exec:");
 728
 729         /*
 730          * If we fail because the command is not found, it is
 731          * OK to return. Otherwise, we just pass along the status code,
 732          * or our usual generic code if we were not even able to exec
 733          * the program.
 734          */
 735         status = run_command(&cmd);
 736
 737         /*
 738          * If the child process ran and we are now going to exit, emit a
 739          * generic string as our trace2 command verb to indicate that we
 740          * launched a dashed command.
 741          */
 742         if (status >= 0)
 743                 exit(status);
 744         else if (errno != ENOENT)
 745                 exit(128);
 746 }
 747
 748 static int run_argv(int *argcp, const char ***argv)
 749 {
 750         int done_alias = 0;
 751         struct string_list cmd_list = STRING_LIST_INIT_NODUP;
 752         struct string_list_item *seen;
 753
 754         while (1) {
 755                 /*
 756                  * If we tried alias and futzed with our environment,
 757                  * it no longer is safe to invoke builtins directly in
 758                  * general.  We have to spawn them as dashed externals.
 759                  *
 760                  * NEEDSWORK: if we can figure out cases
 761                  * where it is safe to do, we can avoid spawning a new
 762                  * process.
 763                  */
 764                 if (!done_alias)
 765                         handle_builtin(*argcp, *argv);
 766                 else if (get_builtin(**argv)) {
 767                         struct child_process cmd = CHILD_PROCESS_INIT;
 768                         int i;
 769
 770                         /*
 771                          * The current process is committed to launching a
 772                          * child process to run the command named in (**argv)
 773                          * and exiting.  Log a generic string as the trace2
 774                          * command verb to indicate this.  Note that the child
 775                          * process will log the actual verb when it runs.
 776                          */
 777                         trace2_cmd_name("_run_git_alias_");
 778
 779                         commit_pager_choice();
 780
 781                         strvec_push(&cmd.args, "git");
 782                         for (i = 0; i < *argcp; i++)
 783                                 strvec_push(&cmd.args, (*argv)[i]);
 784
 785                         trace_argv_printf(cmd.args.v, "trace: exec:");
 786
 787                         /*
 788                          * if we fail because the command is not found, it is
 789                          * OK to return. Otherwise, we just pass along the status code.
 790                          */
 791                         cmd.silent_exec_failure = 1;
 792                         cmd.clean_on_exit = 1;
 793                         cmd.wait_after_clean = 1;
 794                         cmd.trace2_child_class = "git_alias";
 795                         i = run_command(&cmd);
 796                         if (i >= 0 || errno != ENOENT)
 797                                 exit(i);
 798                         die("could not execute builtin %s", **argv);
 799                 }
 800
 801                 /* .. then try the external ones */
 802                 execv_dashed_external(*argv);
 803
 804                 seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
 805                 if (seen) {
 806                         int i;
 807                         struct strbuf sb = STRBUF_INIT;
 808                         for (i = 0; i < cmd_list.nr; i++) {
 809                                 struct string_list_item *item = &cmd_list.items[i];
 810
 811                                 strbuf_addf(&sb, "\n  %s", item->string);
 812                                 if (item == seen)
 813                                         strbuf_addstr(&sb, " <==");
 814                                 else if (i == cmd_list.nr - 1)
 815                                         strbuf_addstr(&sb, " ==>");
 816                         }
 817                         die(_("alias loop detected: expansion of '%s' does"
 818                               " not terminate:%s"), cmd_list.items[0].string, sb.buf);
 819                 }
 820
 821                 string_list_append(&cmd_list, *argv[0]);
 822
 823                 /*
 824                  * It could be an alias -- this works around the insanity
 825                  * of overriding "git log" with "git show" by having
 826                  * alias.log = show
 827                  */
 828                 if (!handle_alias(argcp, argv))
 829                         break;
 830                 done_alias = 1;
 831         }
 832
 833         string_list_clear(&cmd_list, 0);
 834
 835         return done_alias;
 836 }
 837
 838 int cmd_main(int argc, const char **argv)
 839 {
 840         const char *cmd;
 841         int done_help = 0;
 842
 843         cmd = argv[0];
 844         if (!cmd)
 845                 cmd = "git-help";
 846         else {
 847                 const char *slash = find_last_dir_sep(cmd);
 848                 if (slash)
 849                         cmd = slash + 1;
 850         }
 851
 852         trace_command_performance(argv);
 853
 854         /*
 855          * "git-xxxx" is the same as "git xxxx", but we obviously:
 856          *
 857          *  - cannot take flags in between the "git" and the "xxxx".
 858          *  - cannot execute it externally (since it would just do
 859          *    the same thing over again)
 860          *
 861          * So we just directly call the builtin handler, and die if
 862          * that one cannot handle it.
 863          */
 864         if (skip_prefix(cmd, "git-", &cmd)) {
 865                 argv[0] = cmd;
 866                 handle_builtin(argc, argv);
 867                 die(_("cannot handle %s as a builtin"), cmd);
 868         }
 869
 870         /* Look for flags.. */
 871         argv++;
 872         argc--;
 873         handle_options(&argv, &argc, NULL);
 874
 875         if (!argc) {
 876                 /* The user didn't specify a command; give them help */
 877                 commit_pager_choice();
 878                 printf(_("usage: %s\n\n"), git_usage_string);
 879                 list_common_cmds_help();
 880                 printf("\n%s\n", _(git_more_info_string));
 881                 exit(1);
 882         }
 883
 884         if (!strcmp("--version", argv[0]) || !strcmp("-v", argv[0]))
 885                 argv[0] = "version";
 886         else if (!strcmp("--help", argv[0]) || !strcmp("-h", argv[0]))
 887                 argv[0] = "help";
 888
 889         cmd = argv[0];
 890
 891         /*
 892          * We use PATH to find git commands, but we prepend some higher
 893          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 894          * environment, and the $(gitexecdir) from the Makefile at build
 895          * time.
 896          */
 897         setup_path();
 898
 899         while (1) {
 900                 int was_alias = run_argv(&argc, &argv);
 901                 if (errno != ENOENT)
 902                         break;
 903                 if (was_alias) {
 904                         fprintf(stderr, _("expansion of alias '%s' failed; "
 905                                           "'%s' is not a git command\n"),
 906                                 cmd, argv[0]);
 907                         exit(1);
 908                 }
 909                 if (!done_help) {
 910                         cmd = argv[0] = help_unknown_cmd(cmd);
 911                         done_help = 1;
 912                 } else
 913                         break;
 914         }
 915
 916         fprintf(stderr, _("failed to run command '%s': %s\n"),
 917                 cmd, strerror(errno));
 918
 919         return 1;
 920 }