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 "pager.h"
   8 #include "run-command.h"
   9 #include "alias.h"
  10 #include "replace-object.h"
  11 #include "setup.h"
  12 #include "shallow.h"
  13 #include "trace.h"
  14 #include "trace2.h"
  15
  16 #define RUN_SETUP               (1<<0)
  17 #define RUN_SETUP_GENTLY        (1<<1)
  18 #define USE_PAGER               (1<<2)
  19 /*
  20  * require working tree to be present -- anything uses this needs
  21  * RUN_SETUP for reading from the configuration file.
  22  */
  23 #define NEED_WORK_TREE          (1<<3)
  24 #define DELAY_PAGER_CONFIG      (1<<4)
  25 #define NO_PARSEOPT             (1<<5) /* parse-options is not used */
  26
  27 struct cmd_struct {
  28         const char *cmd;
  29         int (*fn)(int, const char **, const char *);
  30         unsigned int option;
  31 };
  32
  33 const char git_usage_string[] =
  34         N_("git [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]\n"
  35            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  36            "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
  37            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  38            "           [--config-env=<name>=<envvar>] <command> [<args>]");
  39
  40 const char git_more_info_string[] =
  41         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  42            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  43            "to read about a specific subcommand or concept.\n"
  44            "See 'git help git' for an overview of the system.");
  45
  46 static int use_pager = -1;
  47
  48 static void list_builtins(struct string_list *list, unsigned int exclude_option);
  49
  50 static void exclude_helpers_from_list(struct string_list *list)
  51 {
  52         int i = 0;
  53
  54         while (i < list->nr) {
  55                 if (strstr(list->items[i].string, "--"))
  56                         unsorted_string_list_delete_item(list, i, 0);
  57                 else
  58                         i++;
  59         }
  60 }
  61
  62 static int match_token(const char *spec, int len, const char *token)
  63 {
  64         int token_len = strlen(token);
  65
  66         return len == token_len && !strncmp(spec, token, token_len);
  67 }
  68
  69 static int list_cmds(const char *spec)
  70 {
  71         struct string_list list = STRING_LIST_INIT_DUP;
  72         int i;
  73         int nongit;
  74
  75         /*
  76         * Set up the repository so we can pick up any repo-level config (like
  77         * completion.commands).
  78         */
  79         setup_git_directory_gently(&nongit);
  80
  81         while (*spec) {
  82                 const char *sep = strchrnul(spec, ',');
  83                 int len = sep - spec;
  84
  85                 if (match_token(spec, len, "builtins"))
  86                         list_builtins(&list, 0);
  87                 else if (match_token(spec, len, "main"))
  88                         list_all_main_cmds(&list);
  89                 else if (match_token(spec, len, "others"))
  90                         list_all_other_cmds(&list);
  91                 else if (match_token(spec, len, "nohelpers"))
  92                         exclude_helpers_from_list(&list);
  93                 else if (match_token(spec, len, "alias"))
  94                         list_aliases(&list);
  95                 else if (match_token(spec, len, "config"))
  96                         list_cmds_by_config(&list);
  97                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
  98                         struct strbuf sb = STRBUF_INIT;
  99
 100                         strbuf_add(&sb, spec + 5, len - 5);
 101                         list_cmds_by_category(&list, sb.buf);
 102                         strbuf_release(&sb);
 103                 }
 104                 else
 105                         die(_("unsupported command listing type '%s'"), spec);
 106                 spec += len;
 107                 if (*spec == ',')
 108                         spec++;
 109         }
 110         for (i = 0; i < list.nr; i++)
 111                 puts(list.items[i].string);
 112         string_list_clear(&list, 0);
 113         return 0;
 114 }
 115
 116 static void commit_pager_choice(void)
 117 {
 118         switch (use_pager) {
 119         case 0:
 120                 setenv("GIT_PAGER", "cat", 1);
 121                 break;
 122         case 1:
 123                 setup_pager();
 124                 break;
 125         default:
 126                 break;
 127         }
 128 }
 129
 130 void setup_auto_pager(const char *cmd, int def)
 131 {
 132         if (use_pager != -1 || pager_in_use())
 133                 return;
 134         use_pager = check_pager_config(cmd);
 135         if (use_pager == -1)
 136                 use_pager = def;
 137         commit_pager_choice();
 138 }
 139
 140 static int handle_options(const char ***argv, int *argc, int *envchanged)
 141 {
 142         const char **orig_argv = *argv;
 143
 144         while (*argc > 0) {
 145                 const char *cmd = (*argv)[0];
 146                 if (cmd[0] != '-')
 147                         break;
 148
 149                 /*
 150                  * For legacy reasons, the "version" and "help"
 151                  * commands can be written with "--" prepended
 152                  * to make them look like flags.
 153                  */
 154                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h") ||
 155                     !strcmp(cmd, "--version") || !strcmp(cmd, "-v"))
 156                         break;
 157
 158                 /*
 159                  * Check remaining flags.
 160                  */
 161                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
 162                         if (*cmd == '=')
 163                                 git_set_exec_path(cmd + 1);
 164                         else {
 165                                 puts(git_exec_path());
 166                                 trace2_cmd_name("_query_");
 167                                 exit(0);
 168                         }
 169                 } else if (!strcmp(cmd, "--html-path")) {
 170                         puts(system_path(GIT_HTML_PATH));
 171                         trace2_cmd_name("_query_");
 172                         exit(0);
 173                 } else if (!strcmp(cmd, "--man-path")) {
 174                         puts(system_path(GIT_MAN_PATH));
 175                         trace2_cmd_name("_query_");
 176                         exit(0);
 177                 } else if (!strcmp(cmd, "--info-path")) {
 178                         puts(system_path(GIT_INFO_PATH));
 179                         trace2_cmd_name("_query_");
 180                         exit(0);
 181                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 182                         use_pager = 1;
 183                 } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
 184                         use_pager = 0;
 185                         if (envchanged)
 186                                 *envchanged = 1;
 187                 } else if (!strcmp(cmd, "--no-replace-objects")) {
 188                         read_replace_refs = 0;
 189                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 190                         if (envchanged)
 191                                 *envchanged = 1;
 192                 } else if (!strcmp(cmd, "--git-dir")) {
 193                         if (*argc < 2) {
 194                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--git-dir");
 195                                 usage(git_usage_string);
 196                         }
 197                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 198                         if (envchanged)
 199                                 *envchanged = 1;
 200                         (*argv)++;
 201                         (*argc)--;
 202                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 203                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 204                         if (envchanged)
 205                                 *envchanged = 1;
 206                 } else if (!strcmp(cmd, "--namespace")) {
 207                         if (*argc < 2) {
 208                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 209                                 usage(git_usage_string);
 210                         }
 211                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 212                         if (envchanged)
 213                                 *envchanged = 1;
 214                         (*argv)++;
 215                         (*argc)--;
 216                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 217                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 218                         if (envchanged)
 219                                 *envchanged = 1;
 220                 } else if (!strcmp(cmd, "--work-tree")) {
 221                         if (*argc < 2) {
 222                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--work-tree");
 223                                 usage(git_usage_string);
 224                         }
 225                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 226                         if (envchanged)
 227                                 *envchanged = 1;
 228                         (*argv)++;
 229                         (*argc)--;
 230                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 231                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 232                         if (envchanged)
 233                                 *envchanged = 1;
 234                 } else if (!strcmp(cmd, "--bare")) {
 235                         char *cwd = xgetcwd();
 236                         is_bare_repository_cfg = 1;
 237                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 238                         free(cwd);
 239                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 240                         if (envchanged)
 241                                 *envchanged = 1;
 242                 } else if (!strcmp(cmd, "-c")) {
 243                         if (*argc < 2) {
 244                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 245                                 usage(git_usage_string);
 246                         }
 247                         git_config_push_parameter((*argv)[1]);
 248                         (*argv)++;
 249                         (*argc)--;
 250                 } else if (!strcmp(cmd, "--config-env")) {
 251                         if (*argc < 2) {
 252                                 fprintf(stderr, _("no config key given for --config-env\n" ));
 253                                 usage(git_usage_string);
 254                         }
 255                         git_config_push_env((*argv)[1]);
 256                         (*argv)++;
 257                         (*argc)--;
 258                 } else if (skip_prefix(cmd, "--config-env=", &cmd)) {
 259                         git_config_push_env(cmd);
 260                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 261                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 262                         if (envchanged)
 263                                 *envchanged = 1;
 264                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 265                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 266                         if (envchanged)
 267                                 *envchanged = 1;
 268                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
 269                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 270                         if (envchanged)
 271                                 *envchanged = 1;
 272                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 273                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 274                         if (envchanged)
 275                                 *envchanged = 1;
 276                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
 277                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 278                         if (envchanged)
 279                                 *envchanged = 1;
 280                 } else if (!strcmp(cmd, "--no-optional-locks")) {
 281                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 282                         if (envchanged)
 283                                 *envchanged = 1;
 284                 } else if (!strcmp(cmd, "--shallow-file")) {
 285                         (*argv)++;
 286                         (*argc)--;
 287                         set_alternate_shallow_file(the_repository, (*argv)[0], 1);
 288                         if (envchanged)
 289                                 *envchanged = 1;
 290                 } else if (!strcmp(cmd, "-C")) {
 291                         if (*argc < 2) {
 292                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "-C");
 293                                 usage(git_usage_string);
 294                         }
 295                         if ((*argv)[1][0]) {
 296                                 if (chdir((*argv)[1]))
 297                                         die_errno("cannot change to '%s'", (*argv)[1]);
 298                                 if (envchanged)
 299                                         *envchanged = 1;
 300                         }
 301                         (*argv)++;
 302                         (*argc)--;
 303                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 304                         trace2_cmd_name("_query_");
 305                         if (!strcmp(cmd, "parseopt")) {
 306                                 struct string_list list = STRING_LIST_INIT_DUP;
 307                                 int i;
 308
 309                                 list_builtins(&list, NO_PARSEOPT);
 310                                 for (i = 0; i < list.nr; i++)
 311                                         printf("%s ", list.items[i].string);
 312                                 string_list_clear(&list, 0);
 313                                 exit(0);
 314                         } else {
 315                                 exit(list_cmds(cmd));
 316                         }
 317                 } else {
 318                         fprintf(stderr, _("unknown option: %s\n"), cmd);
 319                         usage(git_usage_string);
 320                 }
 321
 322                 (*argv)++;
 323                 (*argc)--;
 324         }
 325         return (*argv) - orig_argv;
 326 }
 327
 328 static int handle_alias(int *argcp, const char ***argv)
 329 {
 330         int envchanged = 0, ret = 0, saved_errno = errno;
 331         int count, option_count;
 332         const char **new_argv;
 333         const char *alias_command;
 334         char *alias_string;
 335
 336         alias_command = (*argv)[0];
 337         alias_string = alias_lookup(alias_command);
 338         if (alias_string) {
 339                 if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
 340                         fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
 341                                    alias_command, alias_string);
 342                 if (alias_string[0] == '!') {
 343                         struct child_process child = CHILD_PROCESS_INIT;
 344                         int nongit_ok;
 345
 346                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 347                         setup_git_directory_gently(&nongit_ok);
 348
 349                         commit_pager_choice();
 350
 351                         child.use_shell = 1;
 352                         child.clean_on_exit = 1;
 353                         child.wait_after_clean = 1;
 354                         child.trace2_child_class = "shell_alias";
 355                         strvec_push(&child.args, alias_string + 1);
 356                         strvec_pushv(&child.args, (*argv) + 1);
 357
 358                         trace2_cmd_alias(alias_command, child.args.v);
 359                         trace2_cmd_list_config();
 360                         trace2_cmd_list_env_vars();
 361                         trace2_cmd_name("_run_shell_alias_");
 362
 363                         ret = run_command(&child);
 364                         if (ret >= 0)   /* normal exit */
 365                                 exit(ret);
 366
 367                         die_errno(_("while expanding alias '%s': '%s'"),
 368                                   alias_command, alias_string + 1);
 369                 }
 370                 count = split_cmdline(alias_string, &new_argv);
 371                 if (count < 0)
 372                         die(_("bad alias.%s string: %s"), alias_command,
 373                             _(split_cmdline_strerror(count)));
 374                 option_count = handle_options(&new_argv, &count, &envchanged);
 375                 if (envchanged)
 376                         die(_("alias '%s' changes environment variables.\n"
 377                               "You can use '!git' in the alias to do this"),
 378                             alias_command);
 379                 MOVE_ARRAY(new_argv - option_count, new_argv, count);
 380                 new_argv -= option_count;
 381
 382                 if (count < 1)
 383                         die(_("empty alias for %s"), alias_command);
 384
 385                 if (!strcmp(alias_command, new_argv[0]))
 386                         die(_("recursive alias: %s"), alias_command);
 387
 388                 trace_argv_printf(new_argv,
 389                                   "trace: alias expansion: %s =>",
 390                                   alias_command);
 391
 392                 REALLOC_ARRAY(new_argv, count + *argcp);
 393                 /* insert after command name */
 394                 COPY_ARRAY(new_argv + count, *argv + 1, *argcp);
 395
 396                 trace2_cmd_alias(alias_command, new_argv);
 397                 trace2_cmd_list_config();
 398                 trace2_cmd_list_env_vars();
 399
 400                 *argv = new_argv;
 401                 *argcp += count - 1;
 402
 403                 ret = 1;
 404         }
 405
 406         errno = saved_errno;
 407
 408         return ret;
 409 }
 410
 411 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 412 {
 413         int status, help;
 414         struct stat st;
 415         const char *prefix;
 416         int run_setup = (p->option & (RUN_SETUP | RUN_SETUP_GENTLY));
 417
 418         help = argc == 2 && !strcmp(argv[1], "-h");
 419         if (help && (run_setup & RUN_SETUP))
 420                 /* demote to GENTLY to allow 'git cmd -h' outside repo */
 421                 run_setup = RUN_SETUP_GENTLY;
 422
 423         if (run_setup & RUN_SETUP) {
 424                 prefix = setup_git_directory();
 425         } else if (run_setup & RUN_SETUP_GENTLY) {
 426                 int nongit_ok;
 427                 prefix = setup_git_directory_gently(&nongit_ok);
 428         } else {
 429                 prefix = NULL;
 430         }
 431         assert(!prefix || *prefix);
 432         precompose_argv_prefix(argc, argv, NULL);
 433         if (use_pager == -1 && run_setup &&
 434                 !(p->option & DELAY_PAGER_CONFIG))
 435                 use_pager = check_pager_config(p->cmd);
 436         if (use_pager == -1 && p->option & USE_PAGER)
 437                 use_pager = 1;
 438         if (run_setup && startup_info->have_repository)
 439                 /* get_git_dir() may set up repo, avoid that */
 440                 trace_repo_setup();
 441         commit_pager_choice();
 442
 443         if (!help && p->option & NEED_WORK_TREE)
 444                 setup_work_tree();
 445
 446         trace_argv_printf(argv, "trace: built-in: git");
 447         trace2_cmd_name(p->cmd);
 448         trace2_cmd_list_config();
 449         trace2_cmd_list_env_vars();
 450
 451         validate_cache_entries(the_repository->index);
 452         status = p->fn(argc, argv, prefix);
 453         validate_cache_entries(the_repository->index);
 454
 455         if (status)
 456                 return status;
 457
 458         /* Somebody closed stdout? */
 459         if (fstat(fileno(stdout), &st))
 460                 return 0;
 461         /* Ignore write errors for pipes and sockets.. */
 462         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 463                 return 0;
 464
 465         /* Check for ENOSPC and EIO errors.. */
 466         if (fflush(stdout))
 467                 die_errno(_("write failure on standard output"));
 468         if (ferror(stdout))
 469                 die(_("unknown write failure on standard output"));
 470         if (fclose(stdout))
 471                 die_errno(_("close failed on standard output"));
 472         return 0;
 473 }
 474
 475 static struct cmd_struct commands[] = {
 476         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 477         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 478         { "annotate", cmd_annotate, RUN_SETUP },
 479         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 480         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 481         { "bisect", cmd_bisect, RUN_SETUP },
 482         { "blame", cmd_blame, RUN_SETUP },
 483         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 484         { "bugreport", cmd_bugreport, RUN_SETUP_GENTLY },
 485         { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 486         { "cat-file", cmd_cat_file, RUN_SETUP },
 487         { "check-attr", cmd_check_attr, RUN_SETUP },
 488         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 489         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 490         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 491         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 492         { "checkout--worker", cmd_checkout__worker,
 493                 RUN_SETUP | NEED_WORK_TREE },
 494         { "checkout-index", cmd_checkout_index,
 495                 RUN_SETUP | NEED_WORK_TREE},
 496         { "cherry", cmd_cherry, RUN_SETUP },
 497         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 498         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 499         { "clone", cmd_clone },
 500         { "column", cmd_column, RUN_SETUP_GENTLY },
 501         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 502         { "commit-graph", cmd_commit_graph, RUN_SETUP },
 503         { "commit-tree", cmd_commit_tree, RUN_SETUP },
 504         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 505         { "count-objects", cmd_count_objects, RUN_SETUP },
 506         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 507         { "credential-cache", cmd_credential_cache },
 508         { "credential-cache--daemon", cmd_credential_cache_daemon },
 509         { "credential-store", cmd_credential_store },
 510         { "describe", cmd_describe, RUN_SETUP },
 511         { "diagnose", cmd_diagnose, RUN_SETUP_GENTLY },
 512         { "diff", cmd_diff, NO_PARSEOPT },
 513         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 514         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 515         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 516         { "difftool", cmd_difftool, RUN_SETUP_GENTLY },
 517         { "fast-export", cmd_fast_export, RUN_SETUP },
 518         { "fast-import", cmd_fast_import, RUN_SETUP | NO_PARSEOPT },
 519         { "fetch", cmd_fetch, RUN_SETUP },
 520         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 521         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 522         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 523         { "for-each-repo", cmd_for_each_repo, RUN_SETUP_GENTLY },
 524         { "format-patch", cmd_format_patch, RUN_SETUP },
 525         { "fsck", cmd_fsck, RUN_SETUP },
 526         { "fsck-objects", cmd_fsck, RUN_SETUP },
 527         { "fsmonitor--daemon", cmd_fsmonitor__daemon, RUN_SETUP },
 528         { "gc", cmd_gc, RUN_SETUP },
 529         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 530         { "grep", cmd_grep, RUN_SETUP_GENTLY },
 531         { "hash-object", cmd_hash_object },
 532         { "help", cmd_help },
 533         { "hook", cmd_hook, RUN_SETUP },
 534         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 535         { "init", cmd_init_db },
 536         { "init-db", cmd_init_db },
 537         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 538         { "log", cmd_log, RUN_SETUP },
 539         { "ls-files", cmd_ls_files, RUN_SETUP },
 540         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 541         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 542         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
 543         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 544         { "maintenance", cmd_maintenance, RUN_SETUP },
 545         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 546         { "merge-base", cmd_merge_base, RUN_SETUP },
 547         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 548         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 549         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 550         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 551         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 552         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 553         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 554         { "merge-tree", cmd_merge_tree, RUN_SETUP },
 555         { "mktag", cmd_mktag, RUN_SETUP },
 556         { "mktree", cmd_mktree, RUN_SETUP },
 557         { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP },
 558         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 559         { "name-rev", cmd_name_rev, RUN_SETUP },
 560         { "notes", cmd_notes, RUN_SETUP },
 561         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 562         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 563         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 564         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 565         { "pickaxe", cmd_blame, RUN_SETUP },
 566         { "prune", cmd_prune, RUN_SETUP },
 567         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 568         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 569         { "push", cmd_push, RUN_SETUP },
 570         { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
 571         { "read-tree", cmd_read_tree, RUN_SETUP },
 572         { "rebase", cmd_rebase, RUN_SETUP | NEED_WORK_TREE },
 573         { "receive-pack", cmd_receive_pack },
 574         { "reflog", cmd_reflog, RUN_SETUP },
 575         { "remote", cmd_remote, RUN_SETUP },
 576         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 577         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 578         { "repack", cmd_repack, RUN_SETUP },
 579         { "replace", cmd_replace, RUN_SETUP },
 580         { "rerere", cmd_rerere, RUN_SETUP },
 581         { "reset", cmd_reset, RUN_SETUP },
 582         { "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
 583         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 584         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 585         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 586         { "rm", cmd_rm, RUN_SETUP },
 587         { "send-pack", cmd_send_pack, RUN_SETUP },
 588         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 589         { "show", cmd_show, RUN_SETUP },
 590         { "show-branch", cmd_show_branch, RUN_SETUP },
 591         { "show-index", cmd_show_index, RUN_SETUP_GENTLY },
 592         { "show-ref", cmd_show_ref, RUN_SETUP },
 593         { "sparse-checkout", cmd_sparse_checkout, RUN_SETUP | NEED_WORK_TREE },
 594         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 595         { "stash", cmd_stash, RUN_SETUP | NEED_WORK_TREE },
 596         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 597         { "stripspace", cmd_stripspace },
 598         { "submodule--helper", cmd_submodule__helper, RUN_SETUP },
 599         { "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
 600         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 601         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 602         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 603         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 604         { "update-index", cmd_update_index, RUN_SETUP },
 605         { "update-ref", cmd_update_ref, RUN_SETUP },
 606         { "update-server-info", cmd_update_server_info, RUN_SETUP },
 607         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 608         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 609         { "upload-pack", cmd_upload_pack },
 610         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 611         { "verify-commit", cmd_verify_commit, RUN_SETUP },
 612         { "verify-pack", cmd_verify_pack },
 613         { "verify-tag", cmd_verify_tag, RUN_SETUP },
 614         { "version", cmd_version },
 615         { "whatchanged", cmd_whatchanged, RUN_SETUP },
 616         { "worktree", cmd_worktree, RUN_SETUP },
 617         { "write-tree", cmd_write_tree, RUN_SETUP },
 618 };
 619
 620 static struct cmd_struct *get_builtin(const char *s)
 621 {
 622         int i;
 623         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 624                 struct cmd_struct *p = commands + i;
 625                 if (!strcmp(s, p->cmd))
 626                         return p;
 627         }
 628         return NULL;
 629 }
 630
 631 int is_builtin(const char *s)
 632 {
 633         return !!get_builtin(s);
 634 }
 635
 636 static void list_builtins(struct string_list *out, unsigned int exclude_option)
 637 {
 638         int i;
 639         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 640                 if (exclude_option &&
 641                     (commands[i].option & exclude_option))
 642                         continue;
 643                 string_list_append(out, commands[i].cmd);
 644         }
 645 }
 646
 647 void load_builtin_commands(const char *prefix, struct cmdnames *cmds)
 648 {
 649         const char *name;
 650         int i;
 651
 652         /*
 653          * Callers can ask for a subset of the commands based on a certain
 654          * prefix, which is then dropped from the added names. The names in
 655          * the `commands[]` array do not have the `git-` prefix, though,
 656          * therefore we must expect the `prefix` to at least start with `git-`.
 657          */
 658         if (!skip_prefix(prefix, "git-", &prefix))
 659                 BUG("prefix '%s' must start with 'git-'", prefix);
 660
 661         for (i = 0; i < ARRAY_SIZE(commands); i++)
 662                 if (skip_prefix(commands[i].cmd, prefix, &name))
 663                         add_cmdname(cmds, name, strlen(name));
 664 }
 665
 666 #ifdef STRIP_EXTENSION
 667 static void strip_extension(const char **argv)
 668 {
 669         size_t len;
 670
 671         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 672                 argv[0] = xmemdupz(argv[0], len);
 673 }
 674 #else
 675 #define strip_extension(cmd)
 676 #endif
 677
 678 static void handle_builtin(int argc, const char **argv)
 679 {
 680         struct strvec args = STRVEC_INIT;
 681         const char *cmd;
 682         struct cmd_struct *builtin;
 683
 684         strip_extension(argv);
 685         cmd = argv[0];
 686
 687         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 688         if (argc > 1 && !strcmp(argv[1], "--help")) {
 689                 int i;
 690
 691                 argv[1] = argv[0];
 692                 argv[0] = cmd = "help";
 693
 694                 for (i = 0; i < argc; i++) {
 695                         strvec_push(&args, argv[i]);
 696                         if (!i)
 697                                 strvec_push(&args, "--exclude-guides");
 698                 }
 699
 700                 argc++;
 701                 argv = args.v;
 702         }
 703
 704         builtin = get_builtin(cmd);
 705         if (builtin)
 706                 exit(run_builtin(builtin, argc, argv));
 707         strvec_clear(&args);
 708 }
 709
 710 static void execv_dashed_external(const char **argv)
 711 {
 712         struct child_process cmd = CHILD_PROCESS_INIT;
 713         int status;
 714
 715         if (use_pager == -1 && !is_builtin(argv[0]))
 716                 use_pager = check_pager_config(argv[0]);
 717         commit_pager_choice();
 718
 719         strvec_pushf(&cmd.args, "git-%s", argv[0]);
 720         strvec_pushv(&cmd.args, argv + 1);
 721         cmd.clean_on_exit = 1;
 722         cmd.wait_after_clean = 1;
 723         cmd.silent_exec_failure = 1;
 724         cmd.trace2_child_class = "dashed";
 725
 726         trace2_cmd_name("_run_dashed_");
 727
 728         /*
 729          * The code in run_command() logs trace2 child_start/child_exit
 730          * events, so we do not need to report exec/exec_result events here.
 731          */
 732         trace_argv_printf(cmd.args.v, "trace: exec:");
 733
 734         /*
 735          * If we fail because the command is not found, it is
 736          * OK to return. Otherwise, we just pass along the status code,
 737          * or our usual generic code if we were not even able to exec
 738          * the program.
 739          */
 740         status = run_command(&cmd);
 741
 742         /*
 743          * If the child process ran and we are now going to exit, emit a
 744          * generic string as our trace2 command verb to indicate that we
 745          * launched a dashed command.
 746          */
 747         if (status >= 0)
 748                 exit(status);
 749         else if (errno != ENOENT)
 750                 exit(128);
 751 }
 752
 753 static int run_argv(int *argcp, const char ***argv)
 754 {
 755         int done_alias = 0;
 756         struct string_list cmd_list = STRING_LIST_INIT_NODUP;
 757         struct string_list_item *seen;
 758
 759         while (1) {
 760                 /*
 761                  * If we tried alias and futzed with our environment,
 762                  * it no longer is safe to invoke builtins directly in
 763                  * general.  We have to spawn them as dashed externals.
 764                  *
 765                  * NEEDSWORK: if we can figure out cases
 766                  * where it is safe to do, we can avoid spawning a new
 767                  * process.
 768                  */
 769                 if (!done_alias)
 770                         handle_builtin(*argcp, *argv);
 771                 else if (get_builtin(**argv)) {
 772                         struct child_process cmd = CHILD_PROCESS_INIT;
 773                         int i;
 774
 775                         /*
 776                          * The current process is committed to launching a
 777                          * child process to run the command named in (**argv)
 778                          * and exiting.  Log a generic string as the trace2
 779                          * command verb to indicate this.  Note that the child
 780                          * process will log the actual verb when it runs.
 781                          */
 782                         trace2_cmd_name("_run_git_alias_");
 783
 784                         commit_pager_choice();
 785
 786                         strvec_push(&cmd.args, "git");
 787                         for (i = 0; i < *argcp; i++)
 788                                 strvec_push(&cmd.args, (*argv)[i]);
 789
 790                         trace_argv_printf(cmd.args.v, "trace: exec:");
 791
 792                         /*
 793                          * if we fail because the command is not found, it is
 794                          * OK to return. Otherwise, we just pass along the status code.
 795                          */
 796                         cmd.silent_exec_failure = 1;
 797                         cmd.clean_on_exit = 1;
 798                         cmd.wait_after_clean = 1;
 799                         cmd.trace2_child_class = "git_alias";
 800                         i = run_command(&cmd);
 801                         if (i >= 0 || errno != ENOENT)
 802                                 exit(i);
 803                         die("could not execute builtin %s", **argv);
 804                 }
 805
 806                 /* .. then try the external ones */
 807                 execv_dashed_external(*argv);
 808
 809                 seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
 810                 if (seen) {
 811                         int i;
 812                         struct strbuf sb = STRBUF_INIT;
 813                         for (i = 0; i < cmd_list.nr; i++) {
 814                                 struct string_list_item *item = &cmd_list.items[i];
 815
 816                                 strbuf_addf(&sb, "\n  %s", item->string);
 817                                 if (item == seen)
 818                                         strbuf_addstr(&sb, " <==");
 819                                 else if (i == cmd_list.nr - 1)
 820                                         strbuf_addstr(&sb, " ==>");
 821                         }
 822                         die(_("alias loop detected: expansion of '%s' does"
 823                               " not terminate:%s"), cmd_list.items[0].string, sb.buf);
 824                 }
 825
 826                 string_list_append(&cmd_list, *argv[0]);
 827
 828                 /*
 829                  * It could be an alias -- this works around the insanity
 830                  * of overriding "git log" with "git show" by having
 831                  * alias.log = show
 832                  */
 833                 if (!handle_alias(argcp, argv))
 834                         break;
 835                 done_alias = 1;
 836         }
 837
 838         string_list_clear(&cmd_list, 0);
 839
 840         return done_alias;
 841 }
 842
 843 int cmd_main(int argc, const char **argv)
 844 {
 845         const char *cmd;
 846         int done_help = 0;
 847
 848         cmd = argv[0];
 849         if (!cmd)
 850                 cmd = "git-help";
 851         else {
 852                 const char *slash = find_last_dir_sep(cmd);
 853                 if (slash)
 854                         cmd = slash + 1;
 855         }
 856
 857         trace_command_performance(argv);
 858
 859         /*
 860          * "git-xxxx" is the same as "git xxxx", but we obviously:
 861          *
 862          *  - cannot take flags in between the "git" and the "xxxx".
 863          *  - cannot execute it externally (since it would just do
 864          *    the same thing over again)
 865          *
 866          * So we just directly call the builtin handler, and die if
 867          * that one cannot handle it.
 868          */
 869         if (skip_prefix(cmd, "git-", &cmd)) {
 870                 argv[0] = cmd;
 871                 handle_builtin(argc, argv);
 872                 die(_("cannot handle %s as a builtin"), cmd);
 873         }
 874
 875         /* Look for flags.. */
 876         argv++;
 877         argc--;
 878         handle_options(&argv, &argc, NULL);
 879
 880         if (!argc) {
 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
 889         if (!strcmp("--version", argv[0]) || !strcmp("-v", argv[0]))
 890                 argv[0] = "version";
 891         else if (!strcmp("--help", argv[0]) || !strcmp("-h", argv[0]))
 892                 argv[0] = "help";
 893
 894         cmd = argv[0];
 895
 896         /*
 897          * We use PATH to find git commands, but we prepend some higher
 898          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 899          * environment, and the $(gitexecdir) from the Makefile at build
 900          * time.
 901          */
 902         setup_path();
 903
 904         while (1) {
 905                 int was_alias = run_argv(&argc, &argv);
 906                 if (errno != ENOENT)
 907                         break;
 908                 if (was_alias) {
 909                         fprintf(stderr, _("expansion of alias '%s' failed; "
 910                                           "'%s' is not a git command\n"),
 911                                 cmd, argv[0]);
 912                         exit(1);
 913                 }
 914                 if (!done_help) {
 915                         cmd = argv[0] = help_unknown_cmd(cmd);
 916                         done_help = 1;
 917                 } else
 918                         break;
 919         }
 920
 921         fprintf(stderr, _("failed to run command '%s': %s\n"),
 922                 cmd, strerror(errno));
 923
 924         return 1;
 925 }