git.c

   1 #include "builtin.h"
   2 #include "config.h"
   3 #include "environment.h"
   4 #include "exec-cmd.h"
   5 #include "gettext.h"
   6 #include "help.h"
   7 #include "run-command.h"
   8 #include "alias.h"
   9 #include "replace-object.h"
  10 #include "setup.h"
  11 #include "shallow.h"
  12
  13 #define RUN_SETUP               (1<<0)
  14 #define RUN_SETUP_GENTLY        (1<<1)
  15 #define USE_PAGER               (1<<2)
  16 /*
  17  * require working tree to be present -- anything uses this needs
  18  * RUN_SETUP for reading from the configuration file.
  19  */
  20 #define NEED_WORK_TREE          (1<<3)
  21 #define DELAY_PAGER_CONFIG      (1<<4)
  22 #define NO_PARSEOPT             (1<<5) /* parse-options is not used */
  23
  24 struct cmd_struct {
  25         const char *cmd;
  26         int (*fn)(int, const char **, const char *);
  27         unsigned int option;
  28 };
  29
  30 const char git_usage_string[] =
  31         N_("git [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]\n"
  32            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  33            "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
  34            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  35            "           [--config-env=<name>=<envvar>] <command> [<args>]");
  36
  37 const char git_more_info_string[] =
  38         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  39            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  40            "to read about a specific subcommand or concept.\n"
  41            "See 'git help git' for an overview of the system.");
  42
  43 static int use_pager = -1;
  44
  45 static void list_builtins(struct string_list *list, unsigned int exclude_option);
  46
  47 static void exclude_helpers_from_list(struct string_list *list)
  48 {
  49         int i = 0;
  50
  51         while (i < list->nr) {
  52                 if (strstr(list->items[i].string, "--"))
  53                         unsorted_string_list_delete_item(list, i, 0);
  54                 else
  55                         i++;
  56         }
  57 }
  58
  59 static int match_token(const char *spec, int len, const char *token)
  60 {
  61         int token_len = strlen(token);
  62
  63         return len == token_len && !strncmp(spec, token, token_len);
  64 }
  65
  66 static int list_cmds(const char *spec)
  67 {
  68         struct string_list list = STRING_LIST_INIT_DUP;
  69         int i;
  70         int nongit;
  71
  72         /*
  73         * Set up the repository so we can pick up any repo-level config (like
  74         * completion.commands).
  75         */
  76         setup_git_directory_gently(&nongit);
  77
  78         while (*spec) {
  79                 const char *sep = strchrnul(spec, ',');
  80                 int len = sep - spec;
  81
  82                 if (match_token(spec, len, "builtins"))
  83                         list_builtins(&list, 0);
  84                 else if (match_token(spec, len, "main"))
  85                         list_all_main_cmds(&list);
  86                 else if (match_token(spec, len, "others"))
  87                         list_all_other_cmds(&list);
  88                 else if (match_token(spec, len, "nohelpers"))
  89                         exclude_helpers_from_list(&list);
  90                 else if (match_token(spec, len, "alias"))
  91                         list_aliases(&list);
  92                 else if (match_token(spec, len, "config"))
  93                         list_cmds_by_config(&list);
  94                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
  95                         struct strbuf sb = STRBUF_INIT;
  96
  97                         strbuf_add(&sb, spec + 5, len - 5);
  98                         list_cmds_by_category(&list, sb.buf);
  99                         strbuf_release(&sb);
 100                 }
 101                 else
 102                         die(_("unsupported command listing type '%s'"), spec);
 103                 spec += len;
 104                 if (*spec == ',')
 105                         spec++;
 106         }
 107         for (i = 0; i < list.nr; i++)
 108                 puts(list.items[i].string);
 109         string_list_clear(&list, 0);
 110         return 0;
 111 }
 112
 113 static void commit_pager_choice(void)
 114 {
 115         switch (use_pager) {
 116         case 0:
 117                 setenv("GIT_PAGER", "cat", 1);
 118                 break;
 119         case 1:
 120                 setup_pager();
 121                 break;
 122         default:
 123                 break;
 124         }
 125 }
 126
 127 void setup_auto_pager(const char *cmd, int def)
 128 {
 129         if (use_pager != -1 || pager_in_use())
 130                 return;
 131         use_pager = check_pager_config(cmd);
 132         if (use_pager == -1)
 133                 use_pager = def;
 134         commit_pager_choice();
 135 }
 136
 137 static int handle_options(const char ***argv, int *argc, int *envchanged)
 138 {
 139         const char **orig_argv = *argv;
 140
 141         while (*argc > 0) {
 142                 const char *cmd = (*argv)[0];
 143                 if (cmd[0] != '-')
 144                         break;
 145
 146                 /*
 147                  * For legacy reasons, the "version" and "help"
 148                  * commands can be written with "--" prepended
 149                  * to make them look like flags.
 150                  */
 151                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h") ||
 152                     !strcmp(cmd, "--version") || !strcmp(cmd, "-v"))
 153                         break;
 154
 155                 /*
 156                  * Check remaining flags.
 157                  */
 158                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
 159                         if (*cmd == '=')
 160                                 git_set_exec_path(cmd + 1);
 161                         else {
 162                                 puts(git_exec_path());
 163                                 trace2_cmd_name("_query_");
 164                                 exit(0);
 165                         }
 166                 } else if (!strcmp(cmd, "--html-path")) {
 167                         puts(system_path(GIT_HTML_PATH));
 168                         trace2_cmd_name("_query_");
 169                         exit(0);
 170                 } else if (!strcmp(cmd, "--man-path")) {
 171                         puts(system_path(GIT_MAN_PATH));
 172                         trace2_cmd_name("_query_");
 173                         exit(0);
 174                 } else if (!strcmp(cmd, "--info-path")) {
 175                         puts(system_path(GIT_INFO_PATH));
 176                         trace2_cmd_name("_query_");
 177                         exit(0);
 178                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 179                         use_pager = 1;
 180                 } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
 181                         use_pager = 0;
 182                         if (envchanged)
 183                                 *envchanged = 1;
 184                 } else if (!strcmp(cmd, "--no-replace-objects")) {
 185                         read_replace_refs = 0;
 186                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 187                         if (envchanged)
 188                                 *envchanged = 1;
 189                 } else if (!strcmp(cmd, "--git-dir")) {
 190                         if (*argc < 2) {
 191                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--git-dir");
 192                                 usage(git_usage_string);
 193                         }
 194                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 195                         if (envchanged)
 196                                 *envchanged = 1;
 197                         (*argv)++;
 198                         (*argc)--;
 199                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 200                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 201                         if (envchanged)
 202                                 *envchanged = 1;
 203                 } else if (!strcmp(cmd, "--namespace")) {
 204                         if (*argc < 2) {
 205                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 206                                 usage(git_usage_string);
 207                         }
 208                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 209                         if (envchanged)
 210                                 *envchanged = 1;
 211                         (*argv)++;
 212                         (*argc)--;
 213                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 214                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 215                         if (envchanged)
 216                                 *envchanged = 1;
 217                 } else if (!strcmp(cmd, "--work-tree")) {
 218                         if (*argc < 2) {
 219                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--work-tree");
 220                                 usage(git_usage_string);
 221                         }
 222                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 223                         if (envchanged)
 224                                 *envchanged = 1;
 225                         (*argv)++;
 226                         (*argc)--;
 227                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 228                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 229                         if (envchanged)
 230                                 *envchanged = 1;
 231                 } else if (!strcmp(cmd, "--bare")) {
 232                         char *cwd = xgetcwd();
 233                         is_bare_repository_cfg = 1;
 234                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 235                         free(cwd);
 236                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 237                         if (envchanged)
 238                                 *envchanged = 1;
 239                 } else if (!strcmp(cmd, "-c")) {
 240                         if (*argc < 2) {
 241                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 242                                 usage(git_usage_string);
 243                         }
 244                         git_config_push_parameter((*argv)[1]);
 245                         (*argv)++;
 246                         (*argc)--;
 247                 } else if (!strcmp(cmd, "--config-env")) {
 248                         if (*argc < 2) {
 249                                 fprintf(stderr, _("no config key given for --config-env\n" ));
 250                                 usage(git_usage_string);
 251                         }
 252                         git_config_push_env((*argv)[1]);
 253                         (*argv)++;
 254                         (*argc)--;
 255                 } else if (skip_prefix(cmd, "--config-env=", &cmd)) {
 256                         git_config_push_env(cmd);
 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 '%s' option\n" ), "-C");
 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         int run_setup = (p->option & (RUN_SETUP | RUN_SETUP_GENTLY));
 414
 415         help = argc == 2 && !strcmp(argv[1], "-h");
 416         if (help && (run_setup & RUN_SETUP))
 417                 /* demote to GENTLY to allow 'git cmd -h' outside repo */
 418                 run_setup = RUN_SETUP_GENTLY;
 419
 420         if (run_setup & RUN_SETUP) {
 421                 prefix = setup_git_directory();
 422         } else if (run_setup & RUN_SETUP_GENTLY) {
 423                 int nongit_ok;
 424                 prefix = setup_git_directory_gently(&nongit_ok);
 425         } else {
 426                 prefix = NULL;
 427         }
 428         assert(!prefix || *prefix);
 429         precompose_argv_prefix(argc, argv, NULL);
 430         if (use_pager == -1 && run_setup &&
 431                 !(p->option & DELAY_PAGER_CONFIG))
 432                 use_pager = check_pager_config(p->cmd);
 433         if (use_pager == -1 && p->option & USE_PAGER)
 434                 use_pager = 1;
 435         if (run_setup && startup_info->have_repository)
 436                 /* get_git_dir() may set up repo, avoid that */
 437                 trace_repo_setup();
 438         commit_pager_choice();
 439
 440         if (!help && p->option & NEED_WORK_TREE)
 441                 setup_work_tree();
 442
 443         trace_argv_printf(argv, "trace: built-in: git");
 444         trace2_cmd_name(p->cmd);
 445         trace2_cmd_list_config();
 446         trace2_cmd_list_env_vars();
 447
 448         validate_cache_entries(the_repository->index);
 449         status = p->fn(argc, argv, prefix);
 450         validate_cache_entries(the_repository->index);
 451
 452         if (status)
 453                 return status;
 454
 455         /* Somebody closed stdout? */
 456         if (fstat(fileno(stdout), &st))
 457                 return 0;
 458         /* Ignore write errors for pipes and sockets.. */
 459         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 460                 return 0;
 461
 462         /* Check for ENOSPC and EIO errors.. */
 463         if (fflush(stdout))
 464                 die_errno(_("write failure on standard output"));
 465         if (ferror(stdout))
 466                 die(_("unknown write failure on standard output"));
 467         if (fclose(stdout))
 468                 die_errno(_("close failed on standard output"));
 469         return 0;
 470 }
 471
 472 static struct cmd_struct commands[] = {
 473         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 474         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 475         { "annotate", cmd_annotate, RUN_SETUP },
 476         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 477         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 478         { "bisect", cmd_bisect, RUN_SETUP },
 479         { "blame", cmd_blame, RUN_SETUP },
 480         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 481         { "bugreport", cmd_bugreport, RUN_SETUP_GENTLY },
 482         { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 483         { "cat-file", cmd_cat_file, RUN_SETUP },
 484         { "check-attr", cmd_check_attr, RUN_SETUP },
 485         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 486         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 487         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 488         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 489         { "checkout--worker", cmd_checkout__worker,
 490                 RUN_SETUP | NEED_WORK_TREE },
 491         { "checkout-index", cmd_checkout_index,
 492                 RUN_SETUP | NEED_WORK_TREE},
 493         { "cherry", cmd_cherry, RUN_SETUP },
 494         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 495         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 496         { "clone", cmd_clone },
 497         { "column", cmd_column, RUN_SETUP_GENTLY },
 498         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 499         { "commit-graph", cmd_commit_graph, RUN_SETUP },
 500         { "commit-tree", cmd_commit_tree, RUN_SETUP },
 501         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 502         { "count-objects", cmd_count_objects, RUN_SETUP },
 503         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 504         { "credential-cache", cmd_credential_cache },
 505         { "credential-cache--daemon", cmd_credential_cache_daemon },
 506         { "credential-store", cmd_credential_store },
 507         { "describe", cmd_describe, RUN_SETUP },
 508         { "diagnose", cmd_diagnose, RUN_SETUP_GENTLY },
 509         { "diff", cmd_diff, NO_PARSEOPT },
 510         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 511         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 512         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 513         { "difftool", cmd_difftool, RUN_SETUP_GENTLY },
 514         { "fast-export", cmd_fast_export, RUN_SETUP },
 515         { "fast-import", cmd_fast_import, RUN_SETUP | NO_PARSEOPT },
 516         { "fetch", cmd_fetch, RUN_SETUP },
 517         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 518         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 519         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 520         { "for-each-repo", cmd_for_each_repo, RUN_SETUP_GENTLY },
 521         { "format-patch", cmd_format_patch, RUN_SETUP },
 522         { "fsck", cmd_fsck, RUN_SETUP },
 523         { "fsck-objects", cmd_fsck, RUN_SETUP },
 524         { "fsmonitor--daemon", cmd_fsmonitor__daemon, RUN_SETUP },
 525         { "gc", cmd_gc, RUN_SETUP },
 526         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 527         { "grep", cmd_grep, RUN_SETUP_GENTLY },
 528         { "hash-object", cmd_hash_object },
 529         { "help", cmd_help },
 530         { "hook", cmd_hook, RUN_SETUP },
 531         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 532         { "init", cmd_init_db },
 533         { "init-db", cmd_init_db },
 534         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 535         { "log", cmd_log, RUN_SETUP },
 536         { "ls-files", cmd_ls_files, RUN_SETUP },
 537         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 538         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 539         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
 540         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 541         { "maintenance", cmd_maintenance, RUN_SETUP },
 542         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 543         { "merge-base", cmd_merge_base, RUN_SETUP },
 544         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 545         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 546         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 547         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 548         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 549         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 550         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 551         { "merge-tree", cmd_merge_tree, RUN_SETUP },
 552         { "mktag", cmd_mktag, RUN_SETUP },
 553         { "mktree", cmd_mktree, RUN_SETUP },
 554         { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP },
 555         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 556         { "name-rev", cmd_name_rev, RUN_SETUP },
 557         { "notes", cmd_notes, RUN_SETUP },
 558         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 559         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 560         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 561         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 562         { "pickaxe", cmd_blame, RUN_SETUP },
 563         { "prune", cmd_prune, RUN_SETUP },
 564         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 565         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 566         { "push", cmd_push, RUN_SETUP },
 567         { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
 568         { "read-tree", cmd_read_tree, RUN_SETUP },
 569         { "rebase", cmd_rebase, RUN_SETUP | NEED_WORK_TREE },
 570         { "receive-pack", cmd_receive_pack },
 571         { "reflog", cmd_reflog, RUN_SETUP },
 572         { "remote", cmd_remote, RUN_SETUP },
 573         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 574         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 575         { "repack", cmd_repack, RUN_SETUP },
 576         { "replace", cmd_replace, RUN_SETUP },
 577         { "rerere", cmd_rerere, RUN_SETUP },
 578         { "reset", cmd_reset, RUN_SETUP },
 579         { "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
 580         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 581         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 582         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 583         { "rm", cmd_rm, RUN_SETUP },
 584         { "send-pack", cmd_send_pack, RUN_SETUP },
 585         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 586         { "show", cmd_show, RUN_SETUP },
 587         { "show-branch", cmd_show_branch, RUN_SETUP },
 588         { "show-index", cmd_show_index, RUN_SETUP_GENTLY },
 589         { "show-ref", cmd_show_ref, RUN_SETUP },
 590         { "sparse-checkout", cmd_sparse_checkout, RUN_SETUP },
 591         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 592         { "stash", cmd_stash, RUN_SETUP | NEED_WORK_TREE },
 593         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 594         { "stripspace", cmd_stripspace },
 595         { "submodule--helper", cmd_submodule__helper, RUN_SETUP },
 596         { "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
 597         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 598         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 599         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 600         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 601         { "update-index", cmd_update_index, RUN_SETUP },
 602         { "update-ref", cmd_update_ref, RUN_SETUP },
 603         { "update-server-info", cmd_update_server_info, RUN_SETUP },
 604         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 605         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 606         { "upload-pack", cmd_upload_pack },
 607         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 608         { "verify-commit", cmd_verify_commit, RUN_SETUP },
 609         { "verify-pack", cmd_verify_pack },
 610         { "verify-tag", cmd_verify_tag, RUN_SETUP },
 611         { "version", cmd_version },
 612         { "whatchanged", cmd_whatchanged, RUN_SETUP },
 613         { "worktree", cmd_worktree, RUN_SETUP },
 614         { "write-tree", cmd_write_tree, RUN_SETUP },
 615 };
 616
 617 static struct cmd_struct *get_builtin(const char *s)
 618 {
 619         int i;
 620         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 621                 struct cmd_struct *p = commands + i;
 622                 if (!strcmp(s, p->cmd))
 623                         return p;
 624         }
 625         return NULL;
 626 }
 627
 628 int is_builtin(const char *s)
 629 {
 630         return !!get_builtin(s);
 631 }
 632
 633 static void list_builtins(struct string_list *out, unsigned int exclude_option)
 634 {
 635         int i;
 636         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 637                 if (exclude_option &&
 638                     (commands[i].option & exclude_option))
 639                         continue;
 640                 string_list_append(out, commands[i].cmd);
 641         }
 642 }
 643
 644 void load_builtin_commands(const char *prefix, struct cmdnames *cmds)
 645 {
 646         const char *name;
 647         int i;
 648
 649         /*
 650          * Callers can ask for a subset of the commands based on a certain
 651          * prefix, which is then dropped from the added names. The names in
 652          * the `commands[]` array do not have the `git-` prefix, though,
 653          * therefore we must expect the `prefix` to at least start with `git-`.
 654          */
 655         if (!skip_prefix(prefix, "git-", &prefix))
 656                 BUG("prefix '%s' must start with 'git-'", prefix);
 657
 658         for (i = 0; i < ARRAY_SIZE(commands); i++)
 659                 if (skip_prefix(commands[i].cmd, prefix, &name))
 660                         add_cmdname(cmds, name, strlen(name));
 661 }
 662
 663 #ifdef STRIP_EXTENSION
 664 static void strip_extension(const char **argv)
 665 {
 666         size_t len;
 667
 668         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 669                 argv[0] = xmemdupz(argv[0], len);
 670 }
 671 #else
 672 #define strip_extension(cmd)
 673 #endif
 674
 675 static void handle_builtin(int argc, const char **argv)
 676 {
 677         struct strvec args = STRVEC_INIT;
 678         const char *cmd;
 679         struct cmd_struct *builtin;
 680
 681         strip_extension(argv);
 682         cmd = argv[0];
 683
 684         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 685         if (argc > 1 && !strcmp(argv[1], "--help")) {
 686                 int i;
 687
 688                 argv[1] = argv[0];
 689                 argv[0] = cmd = "help";
 690
 691                 for (i = 0; i < argc; i++) {
 692                         strvec_push(&args, argv[i]);
 693                         if (!i)
 694                                 strvec_push(&args, "--exclude-guides");
 695                 }
 696
 697                 argc++;
 698                 argv = args.v;
 699         }
 700
 701         builtin = get_builtin(cmd);
 702         if (builtin)
 703                 exit(run_builtin(builtin, argc, argv));
 704         strvec_clear(&args);
 705 }
 706
 707 static void execv_dashed_external(const char **argv)
 708 {
 709         struct child_process cmd = CHILD_PROCESS_INIT;
 710         int status;
 711
 712         if (use_pager == -1 && !is_builtin(argv[0]))
 713                 use_pager = check_pager_config(argv[0]);
 714         commit_pager_choice();
 715
 716         strvec_pushf(&cmd.args, "git-%s", argv[0]);
 717         strvec_pushv(&cmd.args, argv + 1);
 718         cmd.clean_on_exit = 1;
 719         cmd.wait_after_clean = 1;
 720         cmd.silent_exec_failure = 1;
 721         cmd.trace2_child_class = "dashed";
 722
 723         trace2_cmd_name("_run_dashed_");
 724
 725         /*
 726          * The code in run_command() logs trace2 child_start/child_exit
 727          * events, so we do not need to report exec/exec_result events here.
 728          */
 729         trace_argv_printf(cmd.args.v, "trace: exec:");
 730
 731         /*
 732          * If we fail because the command is not found, it is
 733          * OK to return. Otherwise, we just pass along the status code,
 734          * or our usual generic code if we were not even able to exec
 735          * the program.
 736          */
 737         status = run_command(&cmd);
 738
 739         /*
 740          * If the child process ran and we are now going to exit, emit a
 741          * generic string as our trace2 command verb to indicate that we
 742          * launched a dashed command.
 743          */
 744         if (status >= 0)
 745                 exit(status);
 746         else if (errno != ENOENT)
 747                 exit(128);
 748 }
 749
 750 static int run_argv(int *argcp, const char ***argv)
 751 {
 752         int done_alias = 0;
 753         struct string_list cmd_list = STRING_LIST_INIT_NODUP;
 754         struct string_list_item *seen;
 755
 756         while (1) {
 757                 /*
 758                  * If we tried alias and futzed with our environment,
 759                  * it no longer is safe to invoke builtins directly in
 760                  * general.  We have to spawn them as dashed externals.
 761                  *
 762                  * NEEDSWORK: if we can figure out cases
 763                  * where it is safe to do, we can avoid spawning a new
 764                  * process.
 765                  */
 766                 if (!done_alias)
 767                         handle_builtin(*argcp, *argv);
 768                 else if (get_builtin(**argv)) {
 769                         struct child_process cmd = CHILD_PROCESS_INIT;
 770                         int i;
 771
 772                         /*
 773                          * The current process is committed to launching a
 774                          * child process to run the command named in (**argv)
 775                          * and exiting.  Log a generic string as the trace2
 776                          * command verb to indicate this.  Note that the child
 777                          * process will log the actual verb when it runs.
 778                          */
 779                         trace2_cmd_name("_run_git_alias_");
 780
 781                         commit_pager_choice();
 782
 783                         strvec_push(&cmd.args, "git");
 784                         for (i = 0; i < *argcp; i++)
 785                                 strvec_push(&cmd.args, (*argv)[i]);
 786
 787                         trace_argv_printf(cmd.args.v, "trace: exec:");
 788
 789                         /*
 790                          * if we fail because the command is not found, it is
 791                          * OK to return. Otherwise, we just pass along the status code.
 792                          */
 793                         cmd.silent_exec_failure = 1;
 794                         cmd.clean_on_exit = 1;
 795                         cmd.wait_after_clean = 1;
 796                         cmd.trace2_child_class = "git_alias";
 797                         i = run_command(&cmd);
 798                         if (i >= 0 || errno != ENOENT)
 799                                 exit(i);
 800                         die("could not execute builtin %s", **argv);
 801                 }
 802
 803                 /* .. then try the external ones */
 804                 execv_dashed_external(*argv);
 805
 806                 seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
 807                 if (seen) {
 808                         int i;
 809                         struct strbuf sb = STRBUF_INIT;
 810                         for (i = 0; i < cmd_list.nr; i++) {
 811                                 struct string_list_item *item = &cmd_list.items[i];
 812
 813                                 strbuf_addf(&sb, "\n  %s", item->string);
 814                                 if (item == seen)
 815                                         strbuf_addstr(&sb, " <==");
 816                                 else if (i == cmd_list.nr - 1)
 817                                         strbuf_addstr(&sb, " ==>");
 818                         }
 819                         die(_("alias loop detected: expansion of '%s' does"
 820                               " not terminate:%s"), cmd_list.items[0].string, sb.buf);
 821                 }
 822
 823                 string_list_append(&cmd_list, *argv[0]);
 824
 825                 /*
 826                  * It could be an alias -- this works around the insanity
 827                  * of overriding "git log" with "git show" by having
 828                  * alias.log = show
 829                  */
 830                 if (!handle_alias(argcp, argv))
 831                         break;
 832                 done_alias = 1;
 833         }
 834
 835         string_list_clear(&cmd_list, 0);
 836
 837         return done_alias;
 838 }
 839
 840 int cmd_main(int argc, const char **argv)
 841 {
 842         const char *cmd;
 843         int done_help = 0;
 844
 845         cmd = argv[0];
 846         if (!cmd)
 847                 cmd = "git-help";
 848         else {
 849                 const char *slash = find_last_dir_sep(cmd);
 850                 if (slash)
 851                         cmd = slash + 1;
 852         }
 853
 854         trace_command_performance(argv);
 855
 856         /*
 857          * "git-xxxx" is the same as "git xxxx", but we obviously:
 858          *
 859          *  - cannot take flags in between the "git" and the "xxxx".
 860          *  - cannot execute it externally (since it would just do
 861          *    the same thing over again)
 862          *
 863          * So we just directly call the builtin handler, and die if
 864          * that one cannot handle it.
 865          */
 866         if (skip_prefix(cmd, "git-", &cmd)) {
 867                 argv[0] = cmd;
 868                 handle_builtin(argc, argv);
 869                 die(_("cannot handle %s as a builtin"), cmd);
 870         }
 871
 872         /* Look for flags.. */
 873         argv++;
 874         argc--;
 875         handle_options(&argv, &argc, NULL);
 876
 877         if (!argc) {
 878                 /* The user didn't specify a command; give them help */
 879                 commit_pager_choice();
 880                 printf(_("usage: %s\n\n"), git_usage_string);
 881                 list_common_cmds_help();
 882                 printf("\n%s\n", _(git_more_info_string));
 883                 exit(1);
 884         }
 885
 886         if (!strcmp("--version", argv[0]) || !strcmp("-v", argv[0]))
 887                 argv[0] = "version";
 888         else if (!strcmp("--help", argv[0]) || !strcmp("-h", argv[0]))
 889                 argv[0] = "help";
 890
 891         cmd = argv[0];
 892
 893         /*
 894          * We use PATH to find git commands, but we prepend some higher
 895          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 896          * environment, and the $(gitexecdir) from the Makefile at build
 897          * time.
 898          */
 899         setup_path();
 900
 901         while (1) {
 902                 int was_alias = run_argv(&argc, &argv);
 903                 if (errno != ENOENT)
 904                         break;
 905                 if (was_alias) {
 906                         fprintf(stderr, _("expansion of alias '%s' failed; "
 907                                           "'%s' is not a git command\n"),
 908                                 cmd, argv[0]);
 909                         exit(1);
 910                 }
 911                 if (!done_help) {
 912                         cmd = argv[0] = help_unknown_cmd(cmd);
 913                         done_help = 1;
 914                 } else
 915                         break;
 916         }
 917
 918         fprintf(stderr, _("failed to run command '%s': %s\n"),
 919                 cmd, strerror(errno));
 920
 921         return 1;
 922 }