git.c

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