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 "attr.h"
  13 #include "shallow.h"
  14 #include "trace.h"
  15 #include "trace2.h"
  16
  17 #define RUN_SETUP               (1<<0)
  18 #define RUN_SETUP_GENTLY        (1<<1)
  19 #define USE_PAGER               (1<<2)
  20 /*
  21  * require working tree to be present -- anything uses this needs
  22  * RUN_SETUP for reading from the configuration file.
  23  */
  24 #define NEED_WORK_TREE          (1<<3)
  25 #define DELAY_PAGER_CONFIG      (1<<4)
  26 #define NO_PARSEOPT             (1<<5) /* parse-options is not used */
  27
  28 struct cmd_struct {
  29         const char *cmd;
  30         int (*fn)(int, const char **, const char *);
  31         unsigned int option;
  32 };
  33
  34 const char git_usage_string[] =
  35         N_("git [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]\n"
  36            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  37            "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
  38            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  39            "           [--config-env=<name>=<envvar>] <command> [<args>]");
  40
  41 const char git_more_info_string[] =
  42         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  43            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  44            "to read about a specific subcommand or concept.\n"
  45            "See 'git help git' for an overview of the system.");
  46
  47 static int use_pager = -1;
  48
  49 static void list_builtins(struct string_list *list, unsigned int exclude_option);
  50
  51 static void exclude_helpers_from_list(struct string_list *list)
  52 {
  53         int i = 0;
  54
  55         while (i < list->nr) {
  56                 if (strstr(list->items[i].string, "--"))
  57                         unsorted_string_list_delete_item(list, i, 0);
  58                 else
  59                         i++;
  60         }
  61 }
  62
  63 static int match_token(const char *spec, int len, const char *token)
  64 {
  65         int token_len = strlen(token);
  66
  67         return len == token_len && !strncmp(spec, token, token_len);
  68 }
  69
  70 static int list_cmds(const char *spec)
  71 {
  72         struct string_list list = STRING_LIST_INIT_DUP;
  73         int i;
  74         int nongit;
  75
  76         /*
  77         * Set up the repository so we can pick up any repo-level config (like
  78         * completion.commands).
  79         */
  80         setup_git_directory_gently(&nongit);
  81
  82         while (*spec) {
  83                 const char *sep = strchrnul(spec, ',');
  84                 int len = sep - spec;
  85
  86                 if (match_token(spec, len, "builtins"))
  87                         list_builtins(&list, 0);
  88                 else if (match_token(spec, len, "main"))
  89                         list_all_main_cmds(&list);
  90                 else if (match_token(spec, len, "others"))
  91                         list_all_other_cmds(&list);
  92                 else if (match_token(spec, len, "nohelpers"))
  93                         exclude_helpers_from_list(&list);
  94                 else if (match_token(spec, len, "alias"))
  95                         list_aliases(&list);
  96                 else if (match_token(spec, len, "config"))
  97                         list_cmds_by_config(&list);
  98                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
  99                         struct strbuf sb = STRBUF_INIT;
 100
 101                         strbuf_add(&sb, spec + 5, len - 5);
 102                         list_cmds_by_category(&list, sb.buf);
 103                         strbuf_release(&sb);
 104                 }
 105                 else
 106                         die(_("unsupported command listing type '%s'"), spec);
 107                 spec += len;
 108                 if (*spec == ',')
 109                         spec++;
 110         }
 111         for (i = 0; i < list.nr; i++)
 112                 puts(list.items[i].string);
 113         string_list_clear(&list, 0);
 114         return 0;
 115 }
 116
 117 static void commit_pager_choice(void)
 118 {
 119         switch (use_pager) {
 120         case 0:
 121                 setenv("GIT_PAGER", "cat", 1);
 122                 break;
 123         case 1:
 124                 setup_pager();
 125                 break;
 126         default:
 127                 break;
 128         }
 129 }
 130
 131 void setup_auto_pager(const char *cmd, int def)
 132 {
 133         if (use_pager != -1 || pager_in_use())
 134                 return;
 135         use_pager = check_pager_config(cmd);
 136         if (use_pager == -1)
 137                 use_pager = def;
 138         commit_pager_choice();
 139 }
 140
 141 static int handle_options(const char ***argv, int *argc, int *envchanged)
 142 {
 143         const char **orig_argv = *argv;
 144
 145         while (*argc > 0) {
 146                 const char *cmd = (*argv)[0];
 147                 if (cmd[0] != '-')
 148                         break;
 149
 150                 /*
 151                  * For legacy reasons, the "version" and "help"
 152                  * commands can be written with "--" prepended
 153                  * to make them look like flags.
 154                  */
 155                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h") ||
 156                     !strcmp(cmd, "--version") || !strcmp(cmd, "-v"))
 157                         break;
 158
 159                 /*
 160                  * Check remaining flags.
 161                  */
 162                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
 163                         if (*cmd == '=')
 164                                 git_set_exec_path(cmd + 1);
 165                         else {
 166                                 puts(git_exec_path());
 167                                 trace2_cmd_name("_query_");
 168                                 exit(0);
 169                         }
 170                 } else if (!strcmp(cmd, "--html-path")) {
 171                         puts(system_path(GIT_HTML_PATH));
 172                         trace2_cmd_name("_query_");
 173                         exit(0);
 174                 } else if (!strcmp(cmd, "--man-path")) {
 175                         puts(system_path(GIT_MAN_PATH));
 176                         trace2_cmd_name("_query_");
 177                         exit(0);
 178                 } else if (!strcmp(cmd, "--info-path")) {
 179                         puts(system_path(GIT_INFO_PATH));
 180                         trace2_cmd_name("_query_");
 181                         exit(0);
 182                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 183                         use_pager = 1;
 184                 } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
 185                         use_pager = 0;
 186                         if (envchanged)
 187                                 *envchanged = 1;
 188                 } else if (!strcmp(cmd, "--no-replace-objects")) {
 189                         read_replace_refs = 0;
 190                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 191                         if (envchanged)
 192                                 *envchanged = 1;
 193                 } else if (!strcmp(cmd, "--git-dir")) {
 194                         if (*argc < 2) {
 195                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--git-dir");
 196                                 usage(git_usage_string);
 197                         }
 198                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 199                         if (envchanged)
 200                                 *envchanged = 1;
 201                         (*argv)++;
 202                         (*argc)--;
 203                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 204                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 205                         if (envchanged)
 206                                 *envchanged = 1;
 207                 } else if (!strcmp(cmd, "--namespace")) {
 208                         if (*argc < 2) {
 209                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 210                                 usage(git_usage_string);
 211                         }
 212                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 213                         if (envchanged)
 214                                 *envchanged = 1;
 215                         (*argv)++;
 216                         (*argc)--;
 217                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 218                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 219                         if (envchanged)
 220                                 *envchanged = 1;
 221                 } else if (!strcmp(cmd, "--work-tree")) {
 222                         if (*argc < 2) {
 223                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "--work-tree");
 224                                 usage(git_usage_string);
 225                         }
 226                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 227                         if (envchanged)
 228                                 *envchanged = 1;
 229                         (*argv)++;
 230                         (*argc)--;
 231                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 232                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 233                         if (envchanged)
 234                                 *envchanged = 1;
 235                 } else if (!strcmp(cmd, "--bare")) {
 236                         char *cwd = xgetcwd();
 237                         is_bare_repository_cfg = 1;
 238                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 239                         free(cwd);
 240                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 241                         if (envchanged)
 242                                 *envchanged = 1;
 243                 } else if (!strcmp(cmd, "-c")) {
 244                         if (*argc < 2) {
 245                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 246                                 usage(git_usage_string);
 247                         }
 248                         git_config_push_parameter((*argv)[1]);
 249                         (*argv)++;
 250                         (*argc)--;
 251                 } else if (!strcmp(cmd, "--config-env")) {
 252                         if (*argc < 2) {
 253                                 fprintf(stderr, _("no config key given for --config-env\n" ));
 254                                 usage(git_usage_string);
 255                         }
 256                         git_config_push_env((*argv)[1]);
 257                         (*argv)++;
 258                         (*argc)--;
 259                 } else if (skip_prefix(cmd, "--config-env=", &cmd)) {
 260                         git_config_push_env(cmd);
 261                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 262                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 263                         if (envchanged)
 264                                 *envchanged = 1;
 265                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 266                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 267                         if (envchanged)
 268                                 *envchanged = 1;
 269                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
 270                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 271                         if (envchanged)
 272                                 *envchanged = 1;
 273                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 274                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 275                         if (envchanged)
 276                                 *envchanged = 1;
 277                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
 278                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 279                         if (envchanged)
 280                                 *envchanged = 1;
 281                 } else if (!strcmp(cmd, "--no-optional-locks")) {
 282                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 283                         if (envchanged)
 284                                 *envchanged = 1;
 285                 } else if (!strcmp(cmd, "--shallow-file")) {
 286                         (*argv)++;
 287                         (*argc)--;
 288                         set_alternate_shallow_file(the_repository, (*argv)[0], 1);
 289                         if (envchanged)
 290                                 *envchanged = 1;
 291                 } else if (!strcmp(cmd, "-C")) {
 292                         if (*argc < 2) {
 293                                 fprintf(stderr, _("no directory given for '%s' option\n" ), "-C");
 294                                 usage(git_usage_string);
 295                         }
 296                         if ((*argv)[1][0]) {
 297                                 if (chdir((*argv)[1]))
 298                                         die_errno("cannot change to '%s'", (*argv)[1]);
 299                                 if (envchanged)
 300                                         *envchanged = 1;
 301                         }
 302                         (*argv)++;
 303                         (*argc)--;
 304                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 305                         trace2_cmd_name("_query_");
 306                         if (!strcmp(cmd, "parseopt")) {
 307                                 struct string_list list = STRING_LIST_INIT_DUP;
 308                                 int i;
 309
 310                                 list_builtins(&list, NO_PARSEOPT);
 311                                 for (i = 0; i < list.nr; i++)
 312                                         printf("%s ", list.items[i].string);
 313                                 string_list_clear(&list, 0);
 314                                 exit(0);
 315                         } else {
 316                                 exit(list_cmds(cmd));
 317                         }
 318                 } else if (!strcmp(cmd, "--attr-source")) {
 319                         if (*argc < 2) {
 320                                 fprintf(stderr, _("no attribute source given for --attr-source\n" ));
 321                                 usage(git_usage_string);
 322                         }
 323                         setenv(GIT_ATTR_SOURCE_ENVIRONMENT, (*argv)[1], 1);
 324                         if (envchanged)
 325                                 *envchanged = 1;
 326                         (*argv)++;
 327                         (*argc)--;
 328                 } else if (skip_prefix(cmd, "--attr-source=", &cmd)) {
 329                         set_git_attr_source(cmd);
 330                         setenv(GIT_ATTR_SOURCE_ENVIRONMENT, cmd, 1);
 331                         if (envchanged)
 332                                 *envchanged = 1;
 333                 } else {
 334                         fprintf(stderr, _("unknown option: %s\n"), cmd);
 335                         usage(git_usage_string);
 336                 }
 337
 338                 (*argv)++;
 339                 (*argc)--;
 340         }
 341         return (*argv) - orig_argv;
 342 }
 343
 344 static int handle_alias(int *argcp, const char ***argv)
 345 {
 346         int envchanged = 0, ret = 0, saved_errno = errno;
 347         int count, option_count;
 348         const char **new_argv;
 349         const char *alias_command;
 350         char *alias_string;
 351
 352         alias_command = (*argv)[0];
 353         alias_string = alias_lookup(alias_command);
 354         if (alias_string) {
 355                 if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
 356                         fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
 357                                    alias_command, alias_string);
 358                 if (alias_string[0] == '!') {
 359                         struct child_process child = CHILD_PROCESS_INIT;
 360                         int nongit_ok;
 361
 362                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 363                         setup_git_directory_gently(&nongit_ok);
 364
 365                         commit_pager_choice();
 366
 367                         child.use_shell = 1;
 368                         child.clean_on_exit = 1;
 369                         child.wait_after_clean = 1;
 370                         child.trace2_child_class = "shell_alias";
 371                         strvec_push(&child.args, alias_string + 1);
 372                         strvec_pushv(&child.args, (*argv) + 1);
 373
 374                         trace2_cmd_alias(alias_command, child.args.v);
 375                         trace2_cmd_list_config();
 376                         trace2_cmd_list_env_vars();
 377                         trace2_cmd_name("_run_shell_alias_");
 378
 379                         ret = run_command(&child);
 380                         if (ret >= 0)   /* normal exit */
 381                                 exit(ret);
 382
 383                         die_errno(_("while expanding alias '%s': '%s'"),
 384                                   alias_command, alias_string + 1);
 385                 }
 386                 count = split_cmdline(alias_string, &new_argv);
 387                 if (count < 0)
 388                         die(_("bad alias.%s string: %s"), alias_command,
 389                             _(split_cmdline_strerror(count)));
 390                 option_count = handle_options(&new_argv, &count, &envchanged);
 391                 if (envchanged)
 392                         die(_("alias '%s' changes environment variables.\n"
 393                               "You can use '!git' in the alias to do this"),
 394                             alias_command);
 395                 MOVE_ARRAY(new_argv - option_count, new_argv, count);
 396                 new_argv -= option_count;
 397
 398                 if (count < 1)
 399                         die(_("empty alias for %s"), alias_command);
 400
 401                 if (!strcmp(alias_command, new_argv[0]))
 402                         die(_("recursive alias: %s"), alias_command);
 403
 404                 trace_argv_printf(new_argv,
 405                                   "trace: alias expansion: %s =>",
 406                                   alias_command);
 407
 408                 REALLOC_ARRAY(new_argv, count + *argcp);
 409                 /* insert after command name */
 410                 COPY_ARRAY(new_argv + count, *argv + 1, *argcp);
 411
 412                 trace2_cmd_alias(alias_command, new_argv);
 413                 trace2_cmd_list_config();
 414                 trace2_cmd_list_env_vars();
 415
 416                 *argv = new_argv;
 417                 *argcp += count - 1;
 418
 419                 ret = 1;
 420         }
 421
 422         errno = saved_errno;
 423
 424         return ret;
 425 }
 426
 427 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 428 {
 429         int status, help;
 430         struct stat st;
 431         const char *prefix;
 432         int run_setup = (p->option & (RUN_SETUP | RUN_SETUP_GENTLY));
 433
 434         help = argc == 2 && !strcmp(argv[1], "-h");
 435         if (help && (run_setup & RUN_SETUP))
 436                 /* demote to GENTLY to allow 'git cmd -h' outside repo */
 437                 run_setup = RUN_SETUP_GENTLY;
 438
 439         if (run_setup & RUN_SETUP) {
 440                 prefix = setup_git_directory();
 441         } else if (run_setup & RUN_SETUP_GENTLY) {
 442                 int nongit_ok;
 443                 prefix = setup_git_directory_gently(&nongit_ok);
 444         } else {
 445                 prefix = NULL;
 446         }
 447         assert(!prefix || *prefix);
 448         precompose_argv_prefix(argc, argv, NULL);
 449         if (use_pager == -1 && run_setup &&
 450                 !(p->option & DELAY_PAGER_CONFIG))
 451                 use_pager = check_pager_config(p->cmd);
 452         if (use_pager == -1 && p->option & USE_PAGER)
 453                 use_pager = 1;
 454         if (run_setup && startup_info->have_repository)
 455                 /* get_git_dir() may set up repo, avoid that */
 456                 trace_repo_setup();
 457         commit_pager_choice();
 458
 459         if (!help && p->option & NEED_WORK_TREE)
 460                 setup_work_tree();
 461
 462         trace_argv_printf(argv, "trace: built-in: git");
 463         trace2_cmd_name(p->cmd);
 464         trace2_cmd_list_config();
 465         trace2_cmd_list_env_vars();
 466
 467         validate_cache_entries(the_repository->index);
 468         status = p->fn(argc, argv, prefix);
 469         validate_cache_entries(the_repository->index);
 470
 471         if (status)
 472                 return status;
 473
 474         /* Somebody closed stdout? */
 475         if (fstat(fileno(stdout), &st))
 476                 return 0;
 477         /* Ignore write errors for pipes and sockets.. */
 478         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 479                 return 0;
 480
 481         /* Check for ENOSPC and EIO errors.. */
 482         if (fflush(stdout))
 483                 die_errno(_("write failure on standard output"));
 484         if (ferror(stdout))
 485                 die(_("unknown write failure on standard output"));
 486         if (fclose(stdout))
 487                 die_errno(_("close failed on standard output"));
 488         return 0;
 489 }
 490
 491 static struct cmd_struct commands[] = {
 492         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 493         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 494         { "annotate", cmd_annotate, RUN_SETUP },
 495         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 496         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 497         { "bisect", cmd_bisect, RUN_SETUP },
 498         { "blame", cmd_blame, RUN_SETUP },
 499         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 500         { "bugreport", cmd_bugreport, RUN_SETUP_GENTLY },
 501         { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 502         { "cat-file", cmd_cat_file, RUN_SETUP },
 503         { "check-attr", cmd_check_attr, RUN_SETUP },
 504         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 505         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 506         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 507         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 508         { "checkout--worker", cmd_checkout__worker,
 509                 RUN_SETUP | NEED_WORK_TREE },
 510         { "checkout-index", cmd_checkout_index,
 511                 RUN_SETUP | NEED_WORK_TREE},
 512         { "cherry", cmd_cherry, RUN_SETUP },
 513         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 514         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 515         { "clone", cmd_clone },
 516         { "column", cmd_column, RUN_SETUP_GENTLY },
 517         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 518         { "commit-graph", cmd_commit_graph, RUN_SETUP },
 519         { "commit-tree", cmd_commit_tree, RUN_SETUP },
 520         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 521         { "count-objects", cmd_count_objects, RUN_SETUP },
 522         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 523         { "credential-cache", cmd_credential_cache },
 524         { "credential-cache--daemon", cmd_credential_cache_daemon },
 525         { "credential-store", cmd_credential_store },
 526         { "describe", cmd_describe, RUN_SETUP },
 527         { "diagnose", cmd_diagnose, RUN_SETUP_GENTLY },
 528         { "diff", cmd_diff, NO_PARSEOPT },
 529         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 530         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 531         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 532         { "difftool", cmd_difftool, RUN_SETUP_GENTLY },
 533         { "fast-export", cmd_fast_export, RUN_SETUP },
 534         { "fast-import", cmd_fast_import, RUN_SETUP | NO_PARSEOPT },
 535         { "fetch", cmd_fetch, RUN_SETUP },
 536         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 537         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 538         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 539         { "for-each-repo", cmd_for_each_repo, RUN_SETUP_GENTLY },
 540         { "format-patch", cmd_format_patch, RUN_SETUP },
 541         { "fsck", cmd_fsck, RUN_SETUP },
 542         { "fsck-objects", cmd_fsck, RUN_SETUP },
 543         { "fsmonitor--daemon", cmd_fsmonitor__daemon, RUN_SETUP },
 544         { "gc", cmd_gc, RUN_SETUP },
 545         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 546         { "grep", cmd_grep, RUN_SETUP_GENTLY },
 547         { "hash-object", cmd_hash_object },
 548         { "help", cmd_help },
 549         { "hook", cmd_hook, RUN_SETUP },
 550         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 551         { "init", cmd_init_db },
 552         { "init-db", cmd_init_db },
 553         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 554         { "log", cmd_log, RUN_SETUP },
 555         { "ls-files", cmd_ls_files, RUN_SETUP },
 556         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 557         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 558         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
 559         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 560         { "maintenance", cmd_maintenance, RUN_SETUP },
 561         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 562         { "merge-base", cmd_merge_base, RUN_SETUP },
 563         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 564         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 565         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 566         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 567         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 568         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 569         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 570         { "merge-tree", cmd_merge_tree, RUN_SETUP },
 571         { "mktag", cmd_mktag, RUN_SETUP },
 572         { "mktree", cmd_mktree, RUN_SETUP },
 573         { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP },
 574         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 575         { "name-rev", cmd_name_rev, RUN_SETUP },
 576         { "notes", cmd_notes, RUN_SETUP },
 577         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 578         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 579         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 580         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 581         { "pickaxe", cmd_blame, RUN_SETUP },
 582         { "prune", cmd_prune, RUN_SETUP },
 583         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 584         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 585         { "push", cmd_push, RUN_SETUP },
 586         { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
 587         { "read-tree", cmd_read_tree, RUN_SETUP },
 588         { "rebase", cmd_rebase, RUN_SETUP | NEED_WORK_TREE },
 589         { "receive-pack", cmd_receive_pack },
 590         { "reflog", cmd_reflog, RUN_SETUP },
 591         { "remote", cmd_remote, RUN_SETUP },
 592         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 593         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 594         { "repack", cmd_repack, RUN_SETUP },
 595         { "replace", cmd_replace, RUN_SETUP },
 596         { "rerere", cmd_rerere, RUN_SETUP },
 597         { "reset", cmd_reset, RUN_SETUP },
 598         { "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
 599         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 600         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 601         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 602         { "rm", cmd_rm, RUN_SETUP },
 603         { "send-pack", cmd_send_pack, RUN_SETUP },
 604         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 605         { "show", cmd_show, RUN_SETUP },
 606         { "show-branch", cmd_show_branch, RUN_SETUP },
 607         { "show-index", cmd_show_index, RUN_SETUP_GENTLY },
 608         { "show-ref", cmd_show_ref, RUN_SETUP },
 609         { "sparse-checkout", cmd_sparse_checkout, RUN_SETUP },
 610         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 611         { "stash", cmd_stash, RUN_SETUP | NEED_WORK_TREE },
 612         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 613         { "stripspace", cmd_stripspace },
 614         { "submodule--helper", cmd_submodule__helper, RUN_SETUP },
 615         { "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
 616         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 617         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 618         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 619         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 620         { "update-index", cmd_update_index, RUN_SETUP },
 621         { "update-ref", cmd_update_ref, RUN_SETUP },
 622         { "update-server-info", cmd_update_server_info, RUN_SETUP },
 623         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 624         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 625         { "upload-pack", cmd_upload_pack },
 626         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 627         { "verify-commit", cmd_verify_commit, RUN_SETUP },
 628         { "verify-pack", cmd_verify_pack },
 629         { "verify-tag", cmd_verify_tag, RUN_SETUP },
 630         { "version", cmd_version },
 631         { "whatchanged", cmd_whatchanged, RUN_SETUP },
 632         { "worktree", cmd_worktree, RUN_SETUP },
 633         { "write-tree", cmd_write_tree, RUN_SETUP },
 634 };
 635
 636 static struct cmd_struct *get_builtin(const char *s)
 637 {
 638         int i;
 639         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 640                 struct cmd_struct *p = commands + i;
 641                 if (!strcmp(s, p->cmd))
 642                         return p;
 643         }
 644         return NULL;
 645 }
 646
 647 int is_builtin(const char *s)
 648 {
 649         return !!get_builtin(s);
 650 }
 651
 652 static void list_builtins(struct string_list *out, unsigned int exclude_option)
 653 {
 654         int i;
 655         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 656                 if (exclude_option &&
 657                     (commands[i].option & exclude_option))
 658                         continue;
 659                 string_list_append(out, commands[i].cmd);
 660         }
 661 }
 662
 663 void load_builtin_commands(const char *prefix, struct cmdnames *cmds)
 664 {
 665         const char *name;
 666         int i;
 667
 668         /*
 669          * Callers can ask for a subset of the commands based on a certain
 670          * prefix, which is then dropped from the added names. The names in
 671          * the `commands[]` array do not have the `git-` prefix, though,
 672          * therefore we must expect the `prefix` to at least start with `git-`.
 673          */
 674         if (!skip_prefix(prefix, "git-", &prefix))
 675                 BUG("prefix '%s' must start with 'git-'", prefix);
 676
 677         for (i = 0; i < ARRAY_SIZE(commands); i++)
 678                 if (skip_prefix(commands[i].cmd, prefix, &name))
 679                         add_cmdname(cmds, name, strlen(name));
 680 }
 681
 682 #ifdef STRIP_EXTENSION
 683 static void strip_extension(const char **argv)
 684 {
 685         size_t len;
 686
 687         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 688                 argv[0] = xmemdupz(argv[0], len);
 689 }
 690 #else
 691 #define strip_extension(cmd)
 692 #endif
 693
 694 static void handle_builtin(int argc, const char **argv)
 695 {
 696         struct strvec args = STRVEC_INIT;
 697         const char *cmd;
 698         struct cmd_struct *builtin;
 699
 700         strip_extension(argv);
 701         cmd = argv[0];
 702
 703         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 704         if (argc > 1 && !strcmp(argv[1], "--help")) {
 705                 int i;
 706
 707                 argv[1] = argv[0];
 708                 argv[0] = cmd = "help";
 709
 710                 for (i = 0; i < argc; i++) {
 711                         strvec_push(&args, argv[i]);
 712                         if (!i)
 713                                 strvec_push(&args, "--exclude-guides");
 714                 }
 715
 716                 argc++;
 717                 argv = args.v;
 718         }
 719
 720         builtin = get_builtin(cmd);
 721         if (builtin)
 722                 exit(run_builtin(builtin, argc, argv));
 723         strvec_clear(&args);
 724 }
 725
 726 static void execv_dashed_external(const char **argv)
 727 {
 728         struct child_process cmd = CHILD_PROCESS_INIT;
 729         int status;
 730
 731         if (use_pager == -1 && !is_builtin(argv[0]))
 732                 use_pager = check_pager_config(argv[0]);
 733         commit_pager_choice();
 734
 735         strvec_pushf(&cmd.args, "git-%s", argv[0]);
 736         strvec_pushv(&cmd.args, argv + 1);
 737         cmd.clean_on_exit = 1;
 738         cmd.wait_after_clean = 1;
 739         cmd.silent_exec_failure = 1;
 740         cmd.trace2_child_class = "dashed";
 741
 742         trace2_cmd_name("_run_dashed_");
 743
 744         /*
 745          * The code in run_command() logs trace2 child_start/child_exit
 746          * events, so we do not need to report exec/exec_result events here.
 747          */
 748         trace_argv_printf(cmd.args.v, "trace: exec:");
 749
 750         /*
 751          * If we fail because the command is not found, it is
 752          * OK to return. Otherwise, we just pass along the status code,
 753          * or our usual generic code if we were not even able to exec
 754          * the program.
 755          */
 756         status = run_command(&cmd);
 757
 758         /*
 759          * If the child process ran and we are now going to exit, emit a
 760          * generic string as our trace2 command verb to indicate that we
 761          * launched a dashed command.
 762          */
 763         if (status >= 0)
 764                 exit(status);
 765         else if (errno != ENOENT)
 766                 exit(128);
 767 }
 768
 769 static int run_argv(int *argcp, const char ***argv)
 770 {
 771         int done_alias = 0;
 772         struct string_list cmd_list = STRING_LIST_INIT_NODUP;
 773         struct string_list_item *seen;
 774
 775         while (1) {
 776                 /*
 777                  * If we tried alias and futzed with our environment,
 778                  * it no longer is safe to invoke builtins directly in
 779                  * general.  We have to spawn them as dashed externals.
 780                  *
 781                  * NEEDSWORK: if we can figure out cases
 782                  * where it is safe to do, we can avoid spawning a new
 783                  * process.
 784                  */
 785                 if (!done_alias)
 786                         handle_builtin(*argcp, *argv);
 787                 else if (get_builtin(**argv)) {
 788                         struct child_process cmd = CHILD_PROCESS_INIT;
 789                         int i;
 790
 791                         /*
 792                          * The current process is committed to launching a
 793                          * child process to run the command named in (**argv)
 794                          * and exiting.  Log a generic string as the trace2
 795                          * command verb to indicate this.  Note that the child
 796                          * process will log the actual verb when it runs.
 797                          */
 798                         trace2_cmd_name("_run_git_alias_");
 799
 800                         commit_pager_choice();
 801
 802                         strvec_push(&cmd.args, "git");
 803                         for (i = 0; i < *argcp; i++)
 804                                 strvec_push(&cmd.args, (*argv)[i]);
 805
 806                         trace_argv_printf(cmd.args.v, "trace: exec:");
 807
 808                         /*
 809                          * if we fail because the command is not found, it is
 810                          * OK to return. Otherwise, we just pass along the status code.
 811                          */
 812                         cmd.silent_exec_failure = 1;
 813                         cmd.clean_on_exit = 1;
 814                         cmd.wait_after_clean = 1;
 815                         cmd.trace2_child_class = "git_alias";
 816                         i = run_command(&cmd);
 817                         if (i >= 0 || errno != ENOENT)
 818                                 exit(i);
 819                         die("could not execute builtin %s", **argv);
 820                 }
 821
 822                 /* .. then try the external ones */
 823                 execv_dashed_external(*argv);
 824
 825                 seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
 826                 if (seen) {
 827                         int i;
 828                         struct strbuf sb = STRBUF_INIT;
 829                         for (i = 0; i < cmd_list.nr; i++) {
 830                                 struct string_list_item *item = &cmd_list.items[i];
 831
 832                                 strbuf_addf(&sb, "\n  %s", item->string);
 833                                 if (item == seen)
 834                                         strbuf_addstr(&sb, " <==");
 835                                 else if (i == cmd_list.nr - 1)
 836                                         strbuf_addstr(&sb, " ==>");
 837                         }
 838                         die(_("alias loop detected: expansion of '%s' does"
 839                               " not terminate:%s"), cmd_list.items[0].string, sb.buf);
 840                 }
 841
 842                 string_list_append(&cmd_list, *argv[0]);
 843
 844                 /*
 845                  * It could be an alias -- this works around the insanity
 846                  * of overriding "git log" with "git show" by having
 847                  * alias.log = show
 848                  */
 849                 if (!handle_alias(argcp, argv))
 850                         break;
 851                 done_alias = 1;
 852         }
 853
 854         string_list_clear(&cmd_list, 0);
 855
 856         return done_alias;
 857 }
 858
 859 int cmd_main(int argc, const char **argv)
 860 {
 861         const char *cmd;
 862         int done_help = 0;
 863
 864         cmd = argv[0];
 865         if (!cmd)
 866                 cmd = "git-help";
 867         else {
 868                 const char *slash = find_last_dir_sep(cmd);
 869                 if (slash)
 870                         cmd = slash + 1;
 871         }
 872
 873         trace_command_performance(argv);
 874
 875         /*
 876          * "git-xxxx" is the same as "git xxxx", but we obviously:
 877          *
 878          *  - cannot take flags in between the "git" and the "xxxx".
 879          *  - cannot execute it externally (since it would just do
 880          *    the same thing over again)
 881          *
 882          * So we just directly call the builtin handler, and die if
 883          * that one cannot handle it.
 884          */
 885         if (skip_prefix(cmd, "git-", &cmd)) {
 886                 argv[0] = cmd;
 887                 handle_builtin(argc, argv);
 888                 die(_("cannot handle %s as a builtin"), cmd);
 889         }
 890
 891         /* Look for flags.. */
 892         argv++;
 893         argc--;
 894         handle_options(&argv, &argc, NULL);
 895
 896         if (!argc) {
 897                 /* The user didn't specify a command; give them help */
 898                 commit_pager_choice();
 899                 printf(_("usage: %s\n\n"), git_usage_string);
 900                 list_common_cmds_help();
 901                 printf("\n%s\n", _(git_more_info_string));
 902                 exit(1);
 903         }
 904
 905         if (!strcmp("--version", argv[0]) || !strcmp("-v", argv[0]))
 906                 argv[0] = "version";
 907         else if (!strcmp("--help", argv[0]) || !strcmp("-h", argv[0]))
 908                 argv[0] = "help";
 909
 910         cmd = argv[0];
 911
 912         /*
 913          * We use PATH to find git commands, but we prepend some higher
 914          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 915          * environment, and the $(gitexecdir) from the Makefile at build
 916          * time.
 917          */
 918         setup_path();
 919
 920         while (1) {
 921                 int was_alias = run_argv(&argc, &argv);
 922                 if (errno != ENOENT)
 923                         break;
 924                 if (was_alias) {
 925                         fprintf(stderr, _("expansion of alias '%s' failed; "
 926                                           "'%s' is not a git command\n"),
 927                                 cmd, argv[0]);
 928                         exit(1);
 929                 }
 930                 if (!done_help) {
 931                         cmd = argv[0] = help_unknown_cmd(cmd);
 932                         done_help = 1;
 933                 } else
 934                         break;
 935         }
 936
 937         fprintf(stderr, _("failed to run command '%s': %s\n"),
 938                 cmd, strerror(errno));
 939
 940         return 1;
 941 }