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 "read-cache-ll.h"
   9 #include "run-command.h"
  10 #include "alias.h"
  11 #include "replace-object.h"
  12 #include "setup.h"
  13 #include "attr.h"
  14 #include "shallow.h"
  15 #include "trace.h"
  16 #include "trace2.h"
  17
  18 #define RUN_SETUP               (1<<0)
  19 #define RUN_SETUP_GENTLY        (1<<1)
  20 #define USE_PAGER               (1<<2)
  21 /*
  22  * require working tree to be present -- anything uses this needs
  23  * RUN_SETUP for reading from the configuration file.
  24  */
  25 #define NEED_WORK_TREE          (1<<3)
  26 #define DELAY_PAGER_CONFIG      (1<<4)
  27 #define NO_PARSEOPT             (1<<5) /* parse-options is not used */
  28
  29 struct cmd_struct {
  30         const char *cmd;
  31         int (*fn)(int, const char **, const char *);
  32         unsigned int option;
  33 };
  34
  35 const char git_usage_string[] =
  36         N_("git [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]\n"
  37            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  38            "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
  39            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  40            "           [--config-env=<name>=<envvar>] <command> [<args>]");
  41
  42 const char git_more_info_string[] =
  43         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  44            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  45            "to read about a specific subcommand or concept.\n"
  46            "See 'git help git' for an overview of the system.");
  47
  48 static int use_pager = -1;
  49
  50 static void list_builtins(struct string_list *list, unsigned int exclude_option);
  51
  52 static void exclude_helpers_from_list(struct string_list *list)
  53 {
  54         int i = 0;
  55
  56         while (i < list->nr) {
  57                 if (strstr(list->items[i].string, "--"))
  58                         unsorted_string_list_delete_item(list, i, 0);
  59                 else
  60                         i++;
  61         }
  62 }
  63
  64 static int match_token(const char *spec, int len, const char *token)
  65 {
  66         int token_len = strlen(token);
  67
  68         return len == token_len && !strncmp(spec, token, token_len);
  69 }
  70
  71 static int list_cmds(const char *spec)
  72 {
  73         struct string_list list = STRING_LIST_INIT_DUP;
  74         int i;
  75         int nongit;
  76
  77         /*
  78         * Set up the repository so we can pick up any repo-level config (like
  79         * completion.commands).
  80         */
  81         setup_git_directory_gently(&nongit);
  82
  83         while (*spec) {
  84                 const char *sep = strchrnul(spec, ',');
  85                 int len = sep - spec;
  86
  87                 if (match_token(spec, len, "builtins"))
  88                         list_builtins(&list, 0);
  89                 else if (match_token(spec, len, "main"))
  90                         list_all_main_cmds(&list);
  91                 else if (match_token(spec, len, "others"))
  92                         list_all_other_cmds(&list);
  93                 else if (match_token(spec, len, "nohelpers"))
  94                         exclude_helpers_from_list(&list);
  95                 else if (match_token(spec, len, "alias"))
  96                         list_aliases(&list);
  97                 else if (match_token(spec, len, "config"))
  98                         list_cmds_by_config(&list);
  99                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
 100                         struct strbuf sb = STRBUF_INIT;
 101
 102                         strbuf_add(&sb, spec + 5, len - 5);
 103                         list_cmds_by_category(&list, sb.buf);
 104                         strbuf_release(&sb);
 105                 }
 106                 else
 107                         die(_("unsupported command listing type '%s'"), spec);
 108                 spec += len;
 109                 if (*spec == ',')
 110                         spec++;
 111         }
 112         for (i = 0; i < list.nr; i++)
 113                 puts(list.items[i].string);
 114         string_list_clear(&list, 0);
 115         return 0;
 116 }
 117
 118 static void commit_pager_choice(void)
 119 {
 120         switch (use_pager) {
 121         case 0:
 122                 setenv("GIT_PAGER", "cat", 1);
 123                 break;
 124         case 1:
 125                 setup_pager();
 126                 break;
 127         default:
 128                 break;
 129         }
 130 }
 131
 132 void setup_auto_pager(const char *cmd, int def)
 133 {
 134         if (use_pager != -1 || pager_in_use())
 135                 return;
 136         use_pager = check_pager_config(cmd);
 137         if (use_pager == -1)
 138                 use_pager = def;
 139         commit_pager_choice();
 140 }
 141
 142 static int handle_options(const char ***argv, int *argc, int *envchanged)
 143 {
 144         const char **orig_argv = *argv;
 145
 146         while (*argc > 0) {
 147                 const char *cmd = (*argv)[0];
 148                 if (cmd[0] != '-')
 149                         break;
 150
 151                 /*
 152                  * For legacy reasons, the "version" and "help"
 153                  * commands can be written with "--" prepended
 154                  * to make them look like flags.
 155                  */
 156                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h") ||
 157                     !strcmp(cmd, "--version") || !strcmp(cmd, "-v"))
 158                         break;
 159
 160                 /*
 161                  * Check remaining flags.
 162                  */
 163                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
 164                         if (*cmd == '=')
 165                                 git_set_exec_path(cmd + 1);
 166                         else {
 167                                 puts(git_exec_path());
 168                                 trace2_cmd_name("_query_");
 169                                 exit(0);
 170                         }
 171                 } else if (!strcmp(cmd, "--html-path")) {
 172                         puts(system_path(GIT_HTML_PATH));
 173                         trace2_cmd_name("_query_");
 174                         exit(0);
 175                 } else if (!strcmp(cmd, "--man-path")) {
 176                         puts(system_path(GIT_MAN_PATH));
 177                         trace2_cmd_name("_query_");
 178                         exit(0);
 179                 } else if (!strcmp(cmd, "--info-path")) {
 180                         puts(system_path(GIT_INFO_PATH));
 181                         trace2_cmd_name("_query_");
 182                         exit(0);
 183                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 184                         use_pager = 1;
 185                 } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
 186                         use_pager = 0;
 187                         if (envchanged)
 188                                 *envchanged = 1;
 189                 } else if (!strcmp(cmd, "--no-replace-objects")) {
 190                         disable_replace_refs();
 191                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 192                         if (envchanged)
 193                                 *envchanged = 1;
 194                 } else if (!strcmp(cmd, "--git-dir")) {
 195                         if (*argc < 2) {
 196                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--git-dir");
 197                                 usage(git_usage_string);
 198                         }
 199                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 200                         if (envchanged)
 201                                 *envchanged = 1;
 202                         (*argv)++;
 203                         (*argc)--;
 204                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 205                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 206                         if (envchanged)
 207                                 *envchanged = 1;
 208                 } else if (!strcmp(cmd, "--namespace")) {
 209                         if (*argc < 2) {
 210                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 211                                 usage(git_usage_string);
 212                         }
 213                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 214                         if (envchanged)
 215                                 *envchanged = 1;
 216                         (*argv)++;
 217                         (*argc)--;
 218                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 219                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 220                         if (envchanged)
 221                                 *envchanged = 1;
 222                 } else if (!strcmp(cmd, "--work-tree")) {
 223                         if (*argc < 2) {
 224                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--work-tree");
 225                                 usage(git_usage_string);
 226                         }
 227                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 228                         if (envchanged)
 229                                 *envchanged = 1;
 230                         (*argv)++;
 231                         (*argc)--;
 232                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 233                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 234                         if (envchanged)
 235                                 *envchanged = 1;
 236                 } else if (!strcmp(cmd, "--bare")) {
 237                         char *cwd = xgetcwd();
 238                         is_bare_repository_cfg = 1;
 239                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 240                         free(cwd);
 241                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 242                         if (envchanged)
 243                                 *envchanged = 1;
 244                 } else if (!strcmp(cmd, "-c")) {
 245                         if (*argc < 2) {
 246                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 247                                 usage(git_usage_string);
 248                         }
 249                         git_config_push_parameter((*argv)[1]);
 250                         (*argv)++;
 251                         (*argc)--;
 252                 } else if (!strcmp(cmd, "--config-env")) {
 253                         if (*argc < 2) {
 254                                 fprintf(stderr, _("no config key given for --config-env\n" ));
 255                                 usage(git_usage_string);
 256                         }
 257                         git_config_push_env((*argv)[1]);
 258                         (*argv)++;
 259                         (*argc)--;
 260                 } else if (skip_prefix(cmd, "--config-env=", &cmd)) {
 261                         git_config_push_env(cmd);
 262                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 263                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 264                         if (envchanged)
 265                                 *envchanged = 1;
 266                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 267                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 268                         if (envchanged)
 269                                 *envchanged = 1;
 270                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
 271                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 272                         if (envchanged)
 273                                 *envchanged = 1;
 274                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 275                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 276                         if (envchanged)
 277                                 *envchanged = 1;
 278                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
 279                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 280                         if (envchanged)
 281                                 *envchanged = 1;
 282                 } else if (!strcmp(cmd, "--no-optional-locks")) {
 283                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 284                         if (envchanged)
 285                                 *envchanged = 1;
 286                 } else if (!strcmp(cmd, "--shallow-file")) {
 287                         (*argv)++;
 288                         (*argc)--;
 289                         set_alternate_shallow_file(the_repository, (*argv)[0], 1);
 290                         if (envchanged)
 291                                 *envchanged = 1;
 292                 } else if (!strcmp(cmd, "-C")) {
 293                         if (*argc < 2) {
 294                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "-C");
 295                                 usage(git_usage_string);
 296                         }
 297                         if ((*argv)[1][0]) {
 298                                 if (chdir((*argv)[1]))
 299                                         die_errno("cannot change to '%s'", (*argv)[1]);
 300                                 if (envchanged)
 301                                         *envchanged = 1;
 302                         }
 303                         (*argv)++;
 304                         (*argc)--;
 305                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 306                         trace2_cmd_name("_query_");
 307                         if (!strcmp(cmd, "parseopt")) {
 308                                 struct string_list list = STRING_LIST_INIT_DUP;
 309                                 int i;
 310
 311                                 list_builtins(&list, NO_PARSEOPT);
 312                                 for (i = 0; i < list.nr; i++)
 313                                         printf("%s ", list.items[i].string);
 314                                 string_list_clear(&list, 0);
 315                                 exit(0);
 316                         } else {
 317                                 exit(list_cmds(cmd));
 318                         }
 319                 } else if (!strcmp(cmd, "--attr-source")) {
 320                         if (*argc < 2) {
 321                                 fprintf(stderr, _("no attribute source given for --attr-source\n" ));
 322                                 usage(git_usage_string);
 323                         }
 324                         setenv(GIT_ATTR_SOURCE_ENVIRONMENT, (*argv)[1], 1);
 325                         if (envchanged)
 326                                 *envchanged = 1;
 327                         (*argv)++;
 328                         (*argc)--;
 329                 } else if (skip_prefix(cmd, "--attr-source=", &cmd)) {
 330                         set_git_attr_source(cmd);
 331                         setenv(GIT_ATTR_SOURCE_ENVIRONMENT, cmd, 1);
 332                         if (envchanged)
 333                                 *envchanged = 1;
 334                 } else {
 335                         fprintf(stderr, _("unknown option: %s\n"), cmd);
 336                         usage(git_usage_string);
 337                 }
 338
 339                 (*argv)++;
 340                 (*argc)--;
 341         }
 342         return (*argv) - orig_argv;
 343 }
 344
 345 static int handle_alias(int *argcp, const char ***argv)
 346 {
 347         int envchanged = 0, ret = 0, saved_errno = errno;
 348         int count, option_count;
 349         const char **new_argv;
 350         const char *alias_command;
 351         char *alias_string;
 352
 353         alias_command = (*argv)[0];
 354         alias_string = alias_lookup(alias_command);
 355         if (alias_string) {
 356                 if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
 357                         fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
 358                                    alias_command, alias_string);
 359                 if (alias_string[0] == '!') {
 360                         struct child_process child = CHILD_PROCESS_INIT;
 361                         int nongit_ok;
 362
 363                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 364                         setup_git_directory_gently(&nongit_ok);
 365
 366                         commit_pager_choice();
 367
 368                         child.use_shell = 1;
 369                         child.clean_on_exit = 1;
 370                         child.wait_after_clean = 1;
 371                         child.trace2_child_class = "shell_alias";
 372                         strvec_push(&child.args, alias_string + 1);
 373                         strvec_pushv(&child.args, (*argv) + 1);
 374
 375                         trace2_cmd_alias(alias_command, child.args.v);
 376                         trace2_cmd_name("_run_shell_alias_");
 377
 378                         ret = run_command(&child);
 379                         if (ret >= 0)   /* normal exit */
 380                                 exit(ret);
 381
 382                         die_errno(_("while expanding alias '%s': '%s'"),
 383                                   alias_command, alias_string + 1);
 384                 }
 385                 count = split_cmdline(alias_string, &new_argv);
 386                 if (count < 0)
 387                         die(_("bad alias.%s string: %s"), alias_command,
 388                             _(split_cmdline_strerror(count)));
 389                 option_count = handle_options(&new_argv, &count, &envchanged);
 390                 if (envchanged)
 391                         die(_("alias '%s' changes environment variables.\n"
 392                               "You can use '!git' in the alias to do this"),
 393                             alias_command);
 394                 MOVE_ARRAY(new_argv - option_count, new_argv, count);
 395                 new_argv -= option_count;
 396
 397                 if (count < 1)
 398                         die(_("empty alias for %s"), alias_command);
 399
 400                 if (!strcmp(alias_command, new_argv[0]))
 401                         die(_("recursive alias: %s"), alias_command);
 402
 403                 trace_argv_printf(new_argv,
 404                                   "trace: alias expansion: %s =>",
 405                                   alias_command);
 406
 407                 REALLOC_ARRAY(new_argv, count + *argcp);
 408                 /* insert after command name */
 409                 COPY_ARRAY(new_argv + count, *argv + 1, *argcp);
 410
 411                 trace2_cmd_alias(alias_command, new_argv);
 412
 413                 *argv = new_argv;
 414                 *argcp += count - 1;
 415
 416                 ret = 1;
 417         }
 418
 419         errno = saved_errno;
 420
 421         return ret;
 422 }
 423
 424 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 425 {
 426         int status, help;
 427         struct stat st;
 428         const char *prefix;
 429         int run_setup = (p->option & (RUN_SETUP | RUN_SETUP_GENTLY));
 430
 431         help = argc == 2 && !strcmp(argv[1], "-h");
 432         if (help && (run_setup & RUN_SETUP))
 433                 /* demote to GENTLY to allow 'git cmd -h' outside repo */
 434                 run_setup = RUN_SETUP_GENTLY;
 435
 436         if (run_setup & RUN_SETUP) {
 437                 prefix = setup_git_directory();
 438         } else if (run_setup & RUN_SETUP_GENTLY) {
 439                 int nongit_ok;
 440                 prefix = setup_git_directory_gently(&nongit_ok);
 441         } else {
 442                 prefix = NULL;
 443         }
 444         assert(!prefix || *prefix);
 445         precompose_argv_prefix(argc, argv, NULL);
 446         if (use_pager == -1 && run_setup &&
 447                 !(p->option & DELAY_PAGER_CONFIG))
 448                 use_pager = check_pager_config(p->cmd);
 449         if (use_pager == -1 && p->option & USE_PAGER)
 450                 use_pager = 1;
 451         if (run_setup && startup_info->have_repository)
 452                 /* get_git_dir() may set up repo, avoid that */
 453                 trace_repo_setup();
 454         commit_pager_choice();
 455
 456         if (!help && p->option & NEED_WORK_TREE)
 457                 setup_work_tree();
 458
 459         trace_argv_printf(argv, "trace: built-in: git");
 460         trace2_cmd_name(p->cmd);
 461
 462         validate_cache_entries(the_repository->index);
 463         status = p->fn(argc, argv, prefix);
 464         validate_cache_entries(the_repository->index);
 465
 466         if (status)
 467                 return status;
 468
 469         /* Somebody closed stdout? */
 470         if (fstat(fileno(stdout), &st))
 471                 return 0;
 472         /* Ignore write errors for pipes and sockets.. */
 473         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 474                 return 0;
 475
 476         /* Check for ENOSPC and EIO errors.. */
 477         if (fflush(stdout))
 478                 die_errno(_("write failure on standard output"));
 479         if (ferror(stdout))
 480                 die(_("unknown write failure on standard output"));
 481         if (fclose(stdout))
 482                 die_errno(_("close failed on standard output"));
 483         return 0;
 484 }
 485
 486 static struct cmd_struct commands[] = {
 487         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 488         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 489         { "annotate", cmd_annotate, RUN_SETUP },
 490         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 491         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 492         { "bisect", cmd_bisect, RUN_SETUP },
 493         { "blame", cmd_blame, RUN_SETUP },
 494         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 495         { "bugreport", cmd_bugreport, RUN_SETUP_GENTLY },
 496         { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 497         { "cat-file", cmd_cat_file, RUN_SETUP },
 498         { "check-attr", cmd_check_attr, RUN_SETUP },
 499         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 500         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 501         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 502         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 503         { "checkout--worker", cmd_checkout__worker,
 504                 RUN_SETUP | NEED_WORK_TREE },
 505         { "checkout-index", cmd_checkout_index,
 506                 RUN_SETUP | NEED_WORK_TREE},
 507         { "cherry", cmd_cherry, RUN_SETUP },
 508         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 509         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 510         { "clone", cmd_clone },
 511         { "column", cmd_column, RUN_SETUP_GENTLY },
 512         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 513         { "commit-graph", cmd_commit_graph, RUN_SETUP },
 514         { "commit-tree", cmd_commit_tree, RUN_SETUP },
 515         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 516         { "count-objects", cmd_count_objects, RUN_SETUP },
 517         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 518         { "credential-cache", cmd_credential_cache },
 519         { "credential-cache--daemon", cmd_credential_cache_daemon },
 520         { "credential-store", cmd_credential_store },
 521         { "describe", cmd_describe, RUN_SETUP },
 522         { "diagnose", cmd_diagnose, RUN_SETUP_GENTLY },
 523         { "diff", cmd_diff, NO_PARSEOPT },
 524         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 525         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 526         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 527         { "difftool", cmd_difftool, RUN_SETUP_GENTLY },
 528         { "fast-export", cmd_fast_export, RUN_SETUP },
 529         { "fast-import", cmd_fast_import, RUN_SETUP | NO_PARSEOPT },
 530         { "fetch", cmd_fetch, RUN_SETUP },
 531         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 532         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 533         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 534         { "for-each-repo", cmd_for_each_repo, RUN_SETUP_GENTLY },
 535         { "format-patch", cmd_format_patch, RUN_SETUP },
 536         { "fsck", cmd_fsck, RUN_SETUP },
 537         { "fsck-objects", cmd_fsck, RUN_SETUP },
 538         { "fsmonitor--daemon", cmd_fsmonitor__daemon, RUN_SETUP },
 539         { "gc", cmd_gc, RUN_SETUP },
 540         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 541         { "grep", cmd_grep, RUN_SETUP_GENTLY },
 542         { "hash-object", cmd_hash_object },
 543         { "help", cmd_help },
 544         { "hook", cmd_hook, RUN_SETUP },
 545         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 546         { "init", cmd_init_db },
 547         { "init-db", cmd_init_db },
 548         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 549         { "log", cmd_log, RUN_SETUP },
 550         { "ls-files", cmd_ls_files, RUN_SETUP },
 551         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 552         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 553         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
 554         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 555         { "maintenance", cmd_maintenance, RUN_SETUP },
 556         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 557         { "merge-base", cmd_merge_base, RUN_SETUP },
 558         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 559         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 560         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 561         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 562         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 563         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 564         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 565         { "merge-tree", cmd_merge_tree, RUN_SETUP },
 566         { "mktag", cmd_mktag, RUN_SETUP },
 567         { "mktree", cmd_mktree, RUN_SETUP },
 568         { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP },
 569         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 570         { "name-rev", cmd_name_rev, RUN_SETUP },
 571         { "notes", cmd_notes, RUN_SETUP },
 572         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 573         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 574         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 575         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 576         { "pickaxe", cmd_blame, RUN_SETUP },
 577         { "prune", cmd_prune, RUN_SETUP },
 578         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 579         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 580         { "push", cmd_push, RUN_SETUP },
 581         { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
 582         { "read-tree", cmd_read_tree, RUN_SETUP },
 583         { "rebase", cmd_rebase, RUN_SETUP | NEED_WORK_TREE },
 584         { "receive-pack", cmd_receive_pack },
 585         { "reflog", cmd_reflog, RUN_SETUP },
 586         { "remote", cmd_remote, RUN_SETUP },
 587         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 588         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 589         { "repack", cmd_repack, RUN_SETUP },
 590         { "replace", cmd_replace, RUN_SETUP },
 591         { "replay", cmd_replay, RUN_SETUP },
 592         { "rerere", cmd_rerere, RUN_SETUP },
 593         { "reset", cmd_reset, RUN_SETUP },
 594         { "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
 595         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 596         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 597         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 598         { "rm", cmd_rm, RUN_SETUP },
 599         { "send-pack", cmd_send_pack, RUN_SETUP },
 600         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 601         { "show", cmd_show, RUN_SETUP },
 602         { "show-branch", cmd_show_branch, RUN_SETUP },
 603         { "show-index", cmd_show_index, RUN_SETUP_GENTLY },
 604         { "show-ref", cmd_show_ref, RUN_SETUP },
 605         { "sparse-checkout", cmd_sparse_checkout, RUN_SETUP },
 606         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 607         { "stash", cmd_stash, RUN_SETUP | NEED_WORK_TREE },
 608         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 609         { "stripspace", cmd_stripspace },
 610         { "submodule--helper", cmd_submodule__helper, RUN_SETUP },
 611         { "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
 612         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 613         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 614         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 615         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 616         { "update-index", cmd_update_index, RUN_SETUP },
 617         { "update-ref", cmd_update_ref, RUN_SETUP },
 618         { "update-server-info", cmd_update_server_info, RUN_SETUP },
 619         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 620         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 621         { "upload-pack", cmd_upload_pack },
 622         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 623         { "verify-commit", cmd_verify_commit, RUN_SETUP },
 624         { "verify-pack", cmd_verify_pack },
 625         { "verify-tag", cmd_verify_tag, RUN_SETUP },
 626         { "version", cmd_version },
 627         { "whatchanged", cmd_whatchanged, RUN_SETUP },
 628         { "worktree", cmd_worktree, RUN_SETUP },
 629         { "write-tree", cmd_write_tree, RUN_SETUP },
 630 };
 631
 632 static struct cmd_struct *get_builtin(const char *s)
 633 {
 634         int i;
 635         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 636                 struct cmd_struct *p = commands + i;
 637                 if (!strcmp(s, p->cmd))
 638                         return p;
 639         }
 640         return NULL;
 641 }
 642
 643 int is_builtin(const char *s)
 644 {
 645         return !!get_builtin(s);
 646 }
 647
 648 static void list_builtins(struct string_list *out, unsigned int exclude_option)
 649 {
 650         int i;
 651         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 652                 if (exclude_option &&
 653                     (commands[i].option & exclude_option))
 654                         continue;
 655                 string_list_append(out, commands[i].cmd);
 656         }
 657 }
 658
 659 void load_builtin_commands(const char *prefix, struct cmdnames *cmds)
 660 {
 661         const char *name;
 662         int i;
 663
 664         /*
 665          * Callers can ask for a subset of the commands based on a certain
 666          * prefix, which is then dropped from the added names. The names in
 667          * the `commands[]` array do not have the `git-` prefix, though,
 668          * therefore we must expect the `prefix` to at least start with `git-`.
 669          */
 670         if (!skip_prefix(prefix, "git-", &prefix))
 671                 BUG("prefix '%s' must start with 'git-'", prefix);
 672
 673         for (i = 0; i < ARRAY_SIZE(commands); i++)
 674                 if (skip_prefix(commands[i].cmd, prefix, &name))
 675                         add_cmdname(cmds, name, strlen(name));
 676 }
 677
 678 #ifdef STRIP_EXTENSION
 679 static void strip_extension(const char **argv)
 680 {
 681         size_t len;
 682
 683         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 684                 argv[0] = xmemdupz(argv[0], len);
 685 }
 686 #else
 687 #define strip_extension(cmd)
 688 #endif
 689
 690 static void handle_builtin(int argc, const char **argv)
 691 {
 692         struct strvec args = STRVEC_INIT;
 693         const char *cmd;
 694         struct cmd_struct *builtin;
 695
 696         strip_extension(argv);
 697         cmd = argv[0];
 698
 699         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 700         if (argc > 1 && !strcmp(argv[1], "--help")) {
 701                 int i;
 702
 703                 argv[1] = argv[0];
 704                 argv[0] = cmd = "help";
 705
 706                 for (i = 0; i < argc; i++) {
 707                         strvec_push(&args, argv[i]);
 708                         if (!i)
 709                                 strvec_push(&args, "--exclude-guides");
 710                 }
 711
 712                 argc++;
 713                 argv = args.v;
 714         }
 715
 716         builtin = get_builtin(cmd);
 717         if (builtin)
 718                 exit(run_builtin(builtin, argc, argv));
 719         strvec_clear(&args);
 720 }
 721
 722 static void execv_dashed_external(const char **argv)
 723 {
 724         struct child_process cmd = CHILD_PROCESS_INIT;
 725         int status;
 726
 727         if (use_pager == -1 && !is_builtin(argv[0]))
 728                 use_pager = check_pager_config(argv[0]);
 729         commit_pager_choice();
 730
 731         strvec_pushf(&cmd.args, "git-%s", argv[0]);
 732         strvec_pushv(&cmd.args, argv + 1);
 733         cmd.clean_on_exit = 1;
 734         cmd.wait_after_clean = 1;
 735         cmd.silent_exec_failure = 1;
 736         cmd.trace2_child_class = "dashed";
 737
 738         trace2_cmd_name("_run_dashed_");
 739
 740         /*
 741          * The code in run_command() logs trace2 child_start/child_exit
 742          * events, so we do not need to report exec/exec_result events here.
 743          */
 744         trace_argv_printf(cmd.args.v, "trace: exec:");
 745
 746         /*
 747          * If we fail because the command is not found, it is
 748          * OK to return. Otherwise, we just pass along the status code,
 749          * or our usual generic code if we were not even able to exec
 750          * the program.
 751          */
 752         status = run_command(&cmd);
 753
 754         /*
 755          * If the child process ran and we are now going to exit, emit a
 756          * generic string as our trace2 command verb to indicate that we
 757          * launched a dashed command.
 758          */
 759         if (status >= 0)
 760                 exit(status);
 761         else if (errno != ENOENT)
 762                 exit(128);
 763 }
 764
 765 static int run_argv(int *argcp, const char ***argv)
 766 {
 767         int done_alias = 0;
 768         struct string_list cmd_list = STRING_LIST_INIT_NODUP;
 769         struct string_list_item *seen;
 770
 771         while (1) {
 772                 /*
 773                  * If we tried alias and futzed with our environment,
 774                  * it no longer is safe to invoke builtins directly in
 775                  * general.  We have to spawn them as dashed externals.
 776                  *
 777                  * NEEDSWORK: if we can figure out cases
 778                  * where it is safe to do, we can avoid spawning a new
 779                  * process.
 780                  */
 781                 if (!done_alias)
 782                         handle_builtin(*argcp, *argv);
 783                 else if (get_builtin(**argv)) {
 784                         struct child_process cmd = CHILD_PROCESS_INIT;
 785                         int i;
 786
 787                         /*
 788                          * The current process is committed to launching a
 789                          * child process to run the command named in (**argv)
 790                          * and exiting.  Log a generic string as the trace2
 791                          * command verb to indicate this.  Note that the child
 792                          * process will log the actual verb when it runs.
 793                          */
 794                         trace2_cmd_name("_run_git_alias_");
 795
 796                         commit_pager_choice();
 797
 798                         strvec_push(&cmd.args, "git");
 799                         for (i = 0; i < *argcp; i++)
 800                                 strvec_push(&cmd.args, (*argv)[i]);
 801
 802                         trace_argv_printf(cmd.args.v, "trace: exec:");
 803
 804                         /*
 805                          * if we fail because the command is not found, it is
 806                          * OK to return. Otherwise, we just pass along the status code.
 807                          */
 808                         cmd.silent_exec_failure = 1;
 809                         cmd.clean_on_exit = 1;
 810                         cmd.wait_after_clean = 1;
 811                         cmd.trace2_child_class = "git_alias";
 812                         i = run_command(&cmd);
 813                         if (i >= 0 || errno != ENOENT)
 814                                 exit(i);
 815                         die("could not execute builtin %s", **argv);
 816                 }
 817
 818                 /* .. then try the external ones */
 819                 execv_dashed_external(*argv);
 820
 821                 seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
 822                 if (seen) {
 823                         int i;
 824                         struct strbuf sb = STRBUF_INIT;
 825                         for (i = 0; i < cmd_list.nr; i++) {
 826                                 struct string_list_item *item = &cmd_list.items[i];
 827
 828                                 strbuf_addf(&sb, "\n  %s", item->string);
 829                                 if (item == seen)
 830                                         strbuf_addstr(&sb, " <==");
 831                                 else if (i == cmd_list.nr - 1)
 832                                         strbuf_addstr(&sb, " ==>");
 833                         }
 834                         die(_("alias loop detected: expansion of '%s' does"
 835                               " not terminate:%s"), cmd_list.items[0].string, sb.buf);
 836                 }
 837
 838                 string_list_append(&cmd_list, *argv[0]);
 839
 840                 /*
 841                  * It could be an alias -- this works around the insanity
 842                  * of overriding "git log" with "git show" by having
 843                  * alias.log = show
 844                  */
 845                 if (!handle_alias(argcp, argv))
 846                         break;
 847                 done_alias = 1;
 848         }
 849
 850         string_list_clear(&cmd_list, 0);
 851
 852         return done_alias;
 853 }
 854
 855 int cmd_main(int argc, const char **argv)
 856 {
 857         const char *cmd;
 858         int done_help = 0;
 859
 860         cmd = argv[0];
 861         if (!cmd)
 862                 cmd = "git-help";
 863         else {
 864                 const char *slash = find_last_dir_sep(cmd);
 865                 if (slash)
 866                         cmd = slash + 1;
 867         }
 868
 869         trace_command_performance(argv);
 870
 871         /*
 872          * "git-xxxx" is the same as "git xxxx", but we obviously:
 873          *
 874          *  - cannot take flags in between the "git" and the "xxxx".
 875          *  - cannot execute it externally (since it would just do
 876          *    the same thing over again)
 877          *
 878          * So we just directly call the builtin handler, and die if
 879          * that one cannot handle it.
 880          */
 881         if (skip_prefix(cmd, "git-", &cmd)) {
 882                 argv[0] = cmd;
 883                 handle_builtin(argc, argv);
 884                 die(_("cannot handle %s as a builtin"), cmd);
 885         }
 886
 887         /* Look for flags.. */
 888         argv++;
 889         argc--;
 890         handle_options(&argv, &argc, NULL);
 891
 892         if (!argc) {
 893                 /* The user didn't specify a command; give them help */
 894                 commit_pager_choice();
 895                 printf(_("usage: %s\n\n"), git_usage_string);
 896                 list_common_cmds_help();
 897                 printf("\n%s\n", _(git_more_info_string));
 898                 exit(1);
 899         }
 900
 901         if (!strcmp("--version", argv[0]) || !strcmp("-v", argv[0]))
 902                 argv[0] = "version";
 903         else if (!strcmp("--help", argv[0]) || !strcmp("-h", argv[0]))
 904                 argv[0] = "help";
 905
 906         cmd = argv[0];
 907
 908         /*
 909          * We use PATH to find git commands, but we prepend some higher
 910          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 911          * environment, and the $(gitexecdir) from the Makefile at build
 912          * time.
 913          */
 914         setup_path();
 915
 916         while (1) {
 917                 int was_alias = run_argv(&argc, &argv);
 918                 if (errno != ENOENT)
 919                         break;
 920                 if (was_alias) {
 921                         fprintf(stderr, _("expansion of alias '%s' failed; "
 922                                           "'%s' is not a git command\n"),
 923                                 cmd, argv[0]);
 924                         exit(1);
 925                 }
 926                 if (!done_help) {
 927                         cmd = argv[0] = help_unknown_cmd(cmd);
 928                         done_help = 1;
 929                 } else
 930                         break;
 931         }
 932
 933         fprintf(stderr, _("failed to run command '%s': %s\n"),
 934                 cmd, strerror(errno));
 935
 936         return 1;
 937 }