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
   8 #define RUN_SETUP               (1<<0)
   9 #define RUN_SETUP_GENTLY        (1<<1)
  10 #define USE_PAGER               (1<<2)
  11 /*
  12  * require working tree to be present -- anything uses this needs
  13  * RUN_SETUP for reading from the configuration file.
  14  */
  15 #define NEED_WORK_TREE          (1<<3)
  16 #define SUPPORT_SUPER_PREFIX    (1<<4)
  17 #define DELAY_PAGER_CONFIG      (1<<5)
  18 #define NO_PARSEOPT             (1<<6) /* parse-options is not used */
  19
  20 struct cmd_struct {
  21         const char *cmd;
  22         int (*fn)(int, const char **, const char *);
  23         unsigned int option;
  24 };
  25
  26 const char git_usage_string[] =
  27         N_("git [--version] [--help] [-C <path>] [-c <name>=<value>]\n"
  28            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  29            "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
  30            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  31            "           <command> [<args>]");
  32
  33 const char git_more_info_string[] =
  34         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  35            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  36            "to read about a specific subcommand or concept.\n"
  37            "See 'git help git' for an overview of the system.");
  38
  39 static int use_pager = -1;
  40
  41 static void list_builtins(struct string_list *list, unsigned int exclude_option);
  42
  43 static void exclude_helpers_from_list(struct string_list *list)
  44 {
  45         int i = 0;
  46
  47         while (i < list->nr) {
  48                 if (strstr(list->items[i].string, "--"))
  49                         unsorted_string_list_delete_item(list, i, 0);
  50                 else
  51                         i++;
  52         }
  53 }
  54
  55 static int match_token(const char *spec, int len, const char *token)
  56 {
  57         int token_len = strlen(token);
  58
  59         return len == token_len && !strncmp(spec, token, token_len);
  60 }
  61
  62 static int list_cmds(const char *spec)
  63 {
  64         struct string_list list = STRING_LIST_INIT_DUP;
  65         int i;
  66         int nongit;
  67
  68         /*
  69         * Set up the repository so we can pick up any repo-level config (like
  70         * completion.commands).
  71         */
  72         setup_git_directory_gently(&nongit);
  73
  74         while (*spec) {
  75                 const char *sep = strchrnul(spec, ',');
  76                 int len = sep - spec;
  77
  78                 if (match_token(spec, len, "builtins"))
  79                         list_builtins(&list, 0);
  80                 else if (match_token(spec, len, "main"))
  81                         list_all_main_cmds(&list);
  82                 else if (match_token(spec, len, "others"))
  83                         list_all_other_cmds(&list);
  84                 else if (match_token(spec, len, "nohelpers"))
  85                         exclude_helpers_from_list(&list);
  86                 else if (match_token(spec, len, "alias"))
  87                         list_aliases(&list);
  88                 else if (match_token(spec, len, "config"))
  89                         list_cmds_by_config(&list);
  90                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
  91                         struct strbuf sb = STRBUF_INIT;
  92
  93                         strbuf_add(&sb, spec + 5, len - 5);
  94                         list_cmds_by_category(&list, sb.buf);
  95                         strbuf_release(&sb);
  96                 }
  97                 else
  98                         die(_("unsupported command listing type '%s'"), spec);
  99                 spec += len;
 100                 if (*spec == ',')
 101                         spec++;
 102         }
 103         for (i = 0; i < list.nr; i++)
 104                 puts(list.items[i].string);
 105         string_list_clear(&list, 0);
 106         return 0;
 107 }
 108
 109 static void commit_pager_choice(void)
 110 {
 111         switch (use_pager) {
 112         case 0:
 113                 setenv("GIT_PAGER", "cat", 1);
 114                 break;
 115         case 1:
 116                 setup_pager();
 117                 break;
 118         default:
 119                 break;
 120         }
 121 }
 122
 123 void setup_auto_pager(const char *cmd, int def)
 124 {
 125         if (use_pager != -1 || pager_in_use())
 126                 return;
 127         use_pager = check_pager_config(cmd);
 128         if (use_pager == -1)
 129                 use_pager = def;
 130         commit_pager_choice();
 131 }
 132
 133 static int handle_options(const char ***argv, int *argc, int *envchanged)
 134 {
 135         const char **orig_argv = *argv;
 136
 137         while (*argc > 0) {
 138                 const char *cmd = (*argv)[0];
 139                 if (cmd[0] != '-')
 140                         break;
 141
 142                 /*
 143                  * For legacy reasons, the "version" and "help"
 144                  * commands can be written with "--" prepended
 145                  * to make them look like flags.
 146                  */
 147                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
 148                         break;
 149
 150                 /*
 151                  * Check remaining flags.
 152                  */
 153                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
 154                         if (*cmd == '=')
 155                                 git_set_exec_path(cmd + 1);
 156                         else {
 157                                 puts(git_exec_path());
 158                                 trace2_cmd_name("_query_");
 159                                 exit(0);
 160                         }
 161                 } else if (!strcmp(cmd, "--html-path")) {
 162                         puts(system_path(GIT_HTML_PATH));
 163                         trace2_cmd_name("_query_");
 164                         exit(0);
 165                 } else if (!strcmp(cmd, "--man-path")) {
 166                         puts(system_path(GIT_MAN_PATH));
 167                         trace2_cmd_name("_query_");
 168                         exit(0);
 169                 } else if (!strcmp(cmd, "--info-path")) {
 170                         puts(system_path(GIT_INFO_PATH));
 171                         trace2_cmd_name("_query_");
 172                         exit(0);
 173                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 174                         use_pager = 1;
 175                 } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
 176                         use_pager = 0;
 177                         if (envchanged)
 178                                 *envchanged = 1;
 179                 } else if (!strcmp(cmd, "--no-replace-objects")) {
 180                         read_replace_refs = 0;
 181                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 182                         if (envchanged)
 183                                 *envchanged = 1;
 184                 } else if (!strcmp(cmd, "--git-dir")) {
 185                         if (*argc < 2) {
 186                                 fprintf(stderr, _("no directory given for --git-dir\n" ));
 187                                 usage(git_usage_string);
 188                         }
 189                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 190                         if (envchanged)
 191                                 *envchanged = 1;
 192                         (*argv)++;
 193                         (*argc)--;
 194                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 195                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 196                         if (envchanged)
 197                                 *envchanged = 1;
 198                 } else if (!strcmp(cmd, "--namespace")) {
 199                         if (*argc < 2) {
 200                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 201                                 usage(git_usage_string);
 202                         }
 203                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 204                         if (envchanged)
 205                                 *envchanged = 1;
 206                         (*argv)++;
 207                         (*argc)--;
 208                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 209                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 210                         if (envchanged)
 211                                 *envchanged = 1;
 212                 } else if (!strcmp(cmd, "--work-tree")) {
 213                         if (*argc < 2) {
 214                                 fprintf(stderr, _("no directory given for --work-tree\n" ));
 215                                 usage(git_usage_string);
 216                         }
 217                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 218                         if (envchanged)
 219                                 *envchanged = 1;
 220                         (*argv)++;
 221                         (*argc)--;
 222                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 223                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 224                         if (envchanged)
 225                                 *envchanged = 1;
 226                 } else if (!strcmp(cmd, "--super-prefix")) {
 227                         if (*argc < 2) {
 228                                 fprintf(stderr, _("no prefix given for --super-prefix\n" ));
 229                                 usage(git_usage_string);
 230                         }
 231                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 232                         if (envchanged)
 233                                 *envchanged = 1;
 234                         (*argv)++;
 235                         (*argc)--;
 236                 } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 237                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 238                         if (envchanged)
 239                                 *envchanged = 1;
 240                 } else if (!strcmp(cmd, "--bare")) {
 241                         char *cwd = xgetcwd();
 242                         is_bare_repository_cfg = 1;
 243                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 244                         free(cwd);
 245                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 246                         if (envchanged)
 247                                 *envchanged = 1;
 248                 } else if (!strcmp(cmd, "-c")) {
 249                         if (*argc < 2) {
 250                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 251                                 usage(git_usage_string);
 252                         }
 253                         git_config_push_parameter((*argv)[1]);
 254                         (*argv)++;
 255                         (*argc)--;
 256                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 257                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 258                         if (envchanged)
 259                                 *envchanged = 1;
 260                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 261                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 262                         if (envchanged)
 263                                 *envchanged = 1;
 264                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
 265                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 266                         if (envchanged)
 267                                 *envchanged = 1;
 268                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 269                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 270                         if (envchanged)
 271                                 *envchanged = 1;
 272                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
 273                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 274                         if (envchanged)
 275                                 *envchanged = 1;
 276                 } else if (!strcmp(cmd, "--no-optional-locks")) {
 277                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 278                         if (envchanged)
 279                                 *envchanged = 1;
 280                 } else if (!strcmp(cmd, "--shallow-file")) {
 281                         (*argv)++;
 282                         (*argc)--;
 283                         set_alternate_shallow_file(the_repository, (*argv)[0], 1);
 284                         if (envchanged)
 285                                 *envchanged = 1;
 286                 } else if (!strcmp(cmd, "-C")) {
 287                         if (*argc < 2) {
 288                                 fprintf(stderr, _("no directory given for -C\n" ));
 289                                 usage(git_usage_string);
 290                         }
 291                         if ((*argv)[1][0]) {
 292                                 if (chdir((*argv)[1]))
 293                                         die_errno("cannot change to '%s'", (*argv)[1]);
 294                                 if (envchanged)
 295                                         *envchanged = 1;
 296                         }
 297                         (*argv)++;
 298                         (*argc)--;
 299                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 300                         trace2_cmd_name("_query_");
 301                         if (!strcmp(cmd, "parseopt")) {
 302                                 struct string_list list = STRING_LIST_INIT_DUP;
 303                                 int i;
 304
 305                                 list_builtins(&list, NO_PARSEOPT);
 306                                 for (i = 0; i < list.nr; i++)
 307                                         printf("%s ", list.items[i].string);
 308                                 string_list_clear(&list, 0);
 309                                 exit(0);
 310                         } else {
 311                                 exit(list_cmds(cmd));
 312                         }
 313                 } else {
 314                         fprintf(stderr, _("unknown option: %s\n"), cmd);
 315                         usage(git_usage_string);
 316                 }
 317
 318                 (*argv)++;
 319                 (*argc)--;
 320         }
 321         return (*argv) - orig_argv;
 322 }
 323
 324 static int handle_alias(int *argcp, const char ***argv)
 325 {
 326         int envchanged = 0, ret = 0, saved_errno = errno;
 327         int count, option_count;
 328         const char **new_argv;
 329         const char *alias_command;
 330         char *alias_string;
 331
 332         alias_command = (*argv)[0];
 333         alias_string = alias_lookup(alias_command);
 334         if (alias_string) {
 335                 if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
 336                         fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
 337                                    alias_command, alias_string);
 338                 if (alias_string[0] == '!') {
 339                         struct child_process child = CHILD_PROCESS_INIT;
 340                         int nongit_ok;
 341
 342                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 343                         setup_git_directory_gently(&nongit_ok);
 344
 345                         commit_pager_choice();
 346
 347                         child.use_shell = 1;
 348                         child.trace2_child_class = "shell_alias";
 349                         argv_array_push(&child.args, alias_string + 1);
 350                         argv_array_pushv(&child.args, (*argv) + 1);
 351
 352                         trace2_cmd_alias(alias_command, child.args.argv);
 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
 411         prefix = NULL;
 412         help = argc == 2 && !strcmp(argv[1], "-h");
 413         if (!help) {
 414                 if (p->option & RUN_SETUP)
 415                         prefix = setup_git_directory();
 416                 else if (p->option & RUN_SETUP_GENTLY) {
 417                         int nongit_ok;
 418                         prefix = setup_git_directory_gently(&nongit_ok);
 419                 }
 420
 421                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
 422                     !(p->option & DELAY_PAGER_CONFIG))
 423                         use_pager = check_pager_config(p->cmd);
 424                 if (use_pager == -1 && p->option & USE_PAGER)
 425                         use_pager = 1;
 426
 427                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 428                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 429                         trace_repo_setup(prefix);
 430         }
 431         commit_pager_choice();
 432
 433         if (!help && get_super_prefix()) {
 434                 if (!(p->option & SUPPORT_SUPER_PREFIX))
 435                         die(_("%s doesn't support --super-prefix"), p->cmd);
 436         }
 437
 438         if (!help && p->option & NEED_WORK_TREE)
 439                 setup_work_tree();
 440
 441         trace_argv_printf(argv, "trace: built-in: git");
 442         trace2_cmd_name(p->cmd);
 443         trace2_cmd_list_config();
 444         trace2_cmd_list_env_vars();
 445
 446         validate_cache_entries(the_repository->index);
 447         status = p->fn(argc, argv, prefix);
 448         validate_cache_entries(the_repository->index);
 449
 450         if (status)
 451                 return status;
 452
 453         /* Somebody closed stdout? */
 454         if (fstat(fileno(stdout), &st))
 455                 return 0;
 456         /* Ignore write errors for pipes and sockets.. */
 457         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 458                 return 0;
 459
 460         /* Check for ENOSPC and EIO errors.. */
 461         if (fflush(stdout))
 462                 die_errno(_("write failure on standard output"));
 463         if (ferror(stdout))
 464                 die(_("unknown write failure on standard output"));
 465         if (fclose(stdout))
 466                 die_errno(_("close failed on standard output"));
 467         return 0;
 468 }
 469
 470 static struct cmd_struct commands[] = {
 471         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 472         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 473         { "annotate", cmd_annotate, RUN_SETUP | NO_PARSEOPT },
 474         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 475         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 476         { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 477         { "blame", cmd_blame, RUN_SETUP },
 478         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 479         { "bundle", cmd_bundle, RUN_SETUP_GENTLY | NO_PARSEOPT },
 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-index", cmd_checkout_index,
 487                 RUN_SETUP | NEED_WORK_TREE},
 488         { "cherry", cmd_cherry, RUN_SETUP },
 489         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 490         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 491         { "clone", cmd_clone },
 492         { "column", cmd_column, RUN_SETUP_GENTLY },
 493         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 494         { "commit-graph", cmd_commit_graph, RUN_SETUP },
 495         { "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
 496         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 497         { "count-objects", cmd_count_objects, RUN_SETUP },
 498         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 499         { "describe", cmd_describe, RUN_SETUP },
 500         { "diff", cmd_diff, NO_PARSEOPT },
 501         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 502         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 503         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 504         { "difftool", cmd_difftool, RUN_SETUP_GENTLY },
 505         { "env--helper", cmd_env__helper },
 506         { "fast-export", cmd_fast_export, RUN_SETUP },
 507         { "fetch", cmd_fetch, RUN_SETUP },
 508         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 509         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 510         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 511         { "format-patch", cmd_format_patch, RUN_SETUP },
 512         { "fsck", cmd_fsck, RUN_SETUP },
 513         { "fsck-objects", cmd_fsck, RUN_SETUP },
 514         { "gc", cmd_gc, RUN_SETUP },
 515         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 516         { "grep", cmd_grep, RUN_SETUP_GENTLY },
 517         { "hash-object", cmd_hash_object },
 518         { "help", cmd_help },
 519         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 520         { "init", cmd_init_db },
 521         { "init-db", cmd_init_db },
 522         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 523         { "log", cmd_log, RUN_SETUP },
 524         { "ls-files", cmd_ls_files, RUN_SETUP },
 525         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 526         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 527         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY | NO_PARSEOPT },
 528         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 529         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 530         { "merge-base", cmd_merge_base, RUN_SETUP },
 531         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 532         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 533         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 534         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 535         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 536         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 537         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 538         { "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
 539         { "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
 540         { "mktree", cmd_mktree, RUN_SETUP },
 541         { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP_GENTLY },
 542         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 543         { "name-rev", cmd_name_rev, RUN_SETUP },
 544         { "notes", cmd_notes, RUN_SETUP },
 545         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 546         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 547         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 548         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 549         { "pickaxe", cmd_blame, RUN_SETUP },
 550         { "prune", cmd_prune, RUN_SETUP },
 551         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 552         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 553         { "push", cmd_push, RUN_SETUP },
 554         { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
 555         { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 556         { "rebase", cmd_rebase, RUN_SETUP | NEED_WORK_TREE },
 557         { "rebase--interactive", cmd_rebase__interactive, RUN_SETUP | NEED_WORK_TREE },
 558         { "receive-pack", cmd_receive_pack },
 559         { "reflog", cmd_reflog, RUN_SETUP },
 560         { "remote", cmd_remote, RUN_SETUP },
 561         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 562         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 563         { "repack", cmd_repack, RUN_SETUP },
 564         { "replace", cmd_replace, RUN_SETUP },
 565         { "rerere", cmd_rerere, RUN_SETUP },
 566         { "reset", cmd_reset, RUN_SETUP },
 567         { "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
 568         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 569         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 570         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 571         { "rm", cmd_rm, RUN_SETUP },
 572         { "send-pack", cmd_send_pack, RUN_SETUP },
 573         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 574         { "show", cmd_show, RUN_SETUP },
 575         { "show-branch", cmd_show_branch, RUN_SETUP },
 576         { "show-index", cmd_show_index, RUN_SETUP_GENTLY },
 577         { "show-ref", cmd_show_ref, RUN_SETUP },
 578         { "sparse-checkout", cmd_sparse_checkout, RUN_SETUP | NEED_WORK_TREE },
 579         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 580         { "stash", cmd_stash, RUN_SETUP | NEED_WORK_TREE },
 581         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 582         { "stripspace", cmd_stripspace },
 583         { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
 584         { "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
 585         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 586         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 587         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 588         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 589         { "update-index", cmd_update_index, RUN_SETUP },
 590         { "update-ref", cmd_update_ref, RUN_SETUP },
 591         { "update-server-info", cmd_update_server_info, RUN_SETUP },
 592         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 593         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 594         { "upload-pack", cmd_upload_pack },
 595         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 596         { "verify-commit", cmd_verify_commit, RUN_SETUP },
 597         { "verify-pack", cmd_verify_pack },
 598         { "verify-tag", cmd_verify_tag, RUN_SETUP },
 599         { "version", cmd_version },
 600         { "whatchanged", cmd_whatchanged, RUN_SETUP },
 601         { "worktree", cmd_worktree, RUN_SETUP | NO_PARSEOPT },
 602         { "write-tree", cmd_write_tree, RUN_SETUP },
 603 };
 604
 605 static struct cmd_struct *get_builtin(const char *s)
 606 {
 607         int i;
 608         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 609                 struct cmd_struct *p = commands + i;
 610                 if (!strcmp(s, p->cmd))
 611                         return p;
 612         }
 613         return NULL;
 614 }
 615
 616 int is_builtin(const char *s)
 617 {
 618         return !!get_builtin(s);
 619 }
 620
 621 static void list_builtins(struct string_list *out, unsigned int exclude_option)
 622 {
 623         int i;
 624         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 625                 if (exclude_option &&
 626                     (commands[i].option & exclude_option))
 627                         continue;
 628                 string_list_append(out, commands[i].cmd);
 629         }
 630 }
 631
 632 #ifdef STRIP_EXTENSION
 633 static void strip_extension(const char **argv)
 634 {
 635         size_t len;
 636
 637         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 638                 argv[0] = xmemdupz(argv[0], len);
 639 }
 640 #else
 641 #define strip_extension(cmd)
 642 #endif
 643
 644 static void handle_builtin(int argc, const char **argv)
 645 {
 646         struct argv_array args = ARGV_ARRAY_INIT;
 647         const char *cmd;
 648         struct cmd_struct *builtin;
 649
 650         strip_extension(argv);
 651         cmd = argv[0];
 652
 653         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 654         if (argc > 1 && !strcmp(argv[1], "--help")) {
 655                 int i;
 656
 657                 argv[1] = argv[0];
 658                 argv[0] = cmd = "help";
 659
 660                 for (i = 0; i < argc; i++) {
 661                         argv_array_push(&args, argv[i]);
 662                         if (!i)
 663                                 argv_array_push(&args, "--exclude-guides");
 664                 }
 665
 666                 argc++;
 667                 argv = args.argv;
 668         }
 669
 670         builtin = get_builtin(cmd);
 671         if (builtin)
 672                 exit(run_builtin(builtin, argc, argv));
 673         argv_array_clear(&args);
 674 }
 675
 676 static void execv_dashed_external(const char **argv)
 677 {
 678         struct child_process cmd = CHILD_PROCESS_INIT;
 679         int status;
 680
 681         if (get_super_prefix())
 682                 die(_("%s doesn't support --super-prefix"), argv[0]);
 683
 684         if (use_pager == -1 && !is_builtin(argv[0]))
 685                 use_pager = check_pager_config(argv[0]);
 686         commit_pager_choice();
 687
 688         argv_array_pushf(&cmd.args, "git-%s", argv[0]);
 689         argv_array_pushv(&cmd.args, argv + 1);
 690         cmd.clean_on_exit = 1;
 691         cmd.wait_after_clean = 1;
 692         cmd.silent_exec_failure = 1;
 693         cmd.trace2_child_class = "dashed";
 694
 695         trace2_cmd_name("_run_dashed_");
 696
 697         /*
 698          * The code in run_command() logs trace2 child_start/child_exit
 699          * events, so we do not need to report exec/exec_result events here.
 700          */
 701         trace_argv_printf(cmd.args.argv, "trace: exec:");
 702
 703         /*
 704          * If we fail because the command is not found, it is
 705          * OK to return. Otherwise, we just pass along the status code,
 706          * or our usual generic code if we were not even able to exec
 707          * the program.
 708          */
 709         status = run_command(&cmd);
 710
 711         /*
 712          * If the child process ran and we are now going to exit, emit a
 713          * generic string as our trace2 command verb to indicate that we
 714          * launched a dashed command.
 715          */
 716         if (status >= 0)
 717                 exit(status);
 718         else if (errno != ENOENT)
 719                 exit(128);
 720 }
 721
 722 static int run_argv(int *argcp, const char ***argv)
 723 {
 724         int done_alias = 0;
 725         struct string_list cmd_list = STRING_LIST_INIT_NODUP;
 726         struct string_list_item *seen;
 727
 728         while (1) {
 729                 /*
 730                  * If we tried alias and futzed with our environment,
 731                  * it no longer is safe to invoke builtins directly in
 732                  * general.  We have to spawn them as dashed externals.
 733                  *
 734                  * NEEDSWORK: if we can figure out cases
 735                  * where it is safe to do, we can avoid spawning a new
 736                  * process.
 737                  */
 738                 if (!done_alias)
 739                         handle_builtin(*argcp, *argv);
 740                 else if (get_builtin(**argv)) {
 741                         struct argv_array args = ARGV_ARRAY_INIT;
 742                         int i;
 743
 744                         /*
 745                          * The current process is committed to launching a
 746                          * child process to run the command named in (**argv)
 747                          * and exiting.  Log a generic string as the trace2
 748                          * command verb to indicate this.  Note that the child
 749                          * process will log the actual verb when it runs.
 750                          */
 751                         trace2_cmd_name("_run_git_alias_");
 752
 753                         if (get_super_prefix())
 754                                 die("%s doesn't support --super-prefix", **argv);
 755
 756                         commit_pager_choice();
 757
 758                         argv_array_push(&args, "git");
 759                         for (i = 0; i < *argcp; i++)
 760                                 argv_array_push(&args, (*argv)[i]);
 761
 762                         trace_argv_printf(args.argv, "trace: exec:");
 763
 764                         /*
 765                          * if we fail because the command is not found, it is
 766                          * OK to return. Otherwise, we just pass along the status code.
 767                          */
 768                         i = run_command_v_opt_tr2(args.argv, RUN_SILENT_EXEC_FAILURE |
 769                                                   RUN_CLEAN_ON_EXIT, "git_alias");
 770                         if (i >= 0 || errno != ENOENT)
 771                                 exit(i);
 772                         die("could not execute builtin %s", **argv);
 773                 }
 774
 775                 /* .. then try the external ones */
 776                 execv_dashed_external(*argv);
 777
 778                 seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
 779                 if (seen) {
 780                         int i;
 781                         struct strbuf sb = STRBUF_INIT;
 782                         for (i = 0; i < cmd_list.nr; i++) {
 783                                 struct string_list_item *item = &cmd_list.items[i];
 784
 785                                 strbuf_addf(&sb, "\n  %s", item->string);
 786                                 if (item == seen)
 787                                         strbuf_addstr(&sb, " <==");
 788                                 else if (i == cmd_list.nr - 1)
 789                                         strbuf_addstr(&sb, " ==>");
 790                         }
 791                         die(_("alias loop detected: expansion of '%s' does"
 792                               " not terminate:%s"), cmd_list.items[0].string, sb.buf);
 793                 }
 794
 795                 string_list_append(&cmd_list, *argv[0]);
 796
 797                 /*
 798                  * It could be an alias -- this works around the insanity
 799                  * of overriding "git log" with "git show" by having
 800                  * alias.log = show
 801                  */
 802                 if (!handle_alias(argcp, argv))
 803                         break;
 804                 done_alias = 1;
 805         }
 806
 807         string_list_clear(&cmd_list, 0);
 808
 809         return done_alias;
 810 }
 811
 812 int cmd_main(int argc, const char **argv)
 813 {
 814         const char *cmd;
 815         int done_help = 0;
 816
 817         cmd = argv[0];
 818         if (!cmd)
 819                 cmd = "git-help";
 820         else {
 821                 const char *slash = find_last_dir_sep(cmd);
 822                 if (slash)
 823                         cmd = slash + 1;
 824         }
 825
 826         trace_command_performance(argv);
 827
 828         /*
 829          * "git-xxxx" is the same as "git xxxx", but we obviously:
 830          *
 831          *  - cannot take flags in between the "git" and the "xxxx".
 832          *  - cannot execute it externally (since it would just do
 833          *    the same thing over again)
 834          *
 835          * So we just directly call the builtin handler, and die if
 836          * that one cannot handle it.
 837          */
 838         if (skip_prefix(cmd, "git-", &cmd)) {
 839                 argv[0] = cmd;
 840                 handle_builtin(argc, argv);
 841                 die(_("cannot handle %s as a builtin"), cmd);
 842         }
 843
 844         /* Look for flags.. */
 845         argv++;
 846         argc--;
 847         handle_options(&argv, &argc, NULL);
 848         if (argc > 0) {
 849                 /* translate --help and --version into commands */
 850                 skip_prefix(argv[0], "--", &argv[0]);
 851         } else {
 852                 /* The user didn't specify a command; give them help */
 853                 commit_pager_choice();
 854                 printf(_("usage: %s\n\n"), git_usage_string);
 855                 list_common_cmds_help();
 856                 printf("\n%s\n", _(git_more_info_string));
 857                 exit(1);
 858         }
 859         cmd = argv[0];
 860
 861         /*
 862          * We use PATH to find git commands, but we prepend some higher
 863          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 864          * environment, and the $(gitexecdir) from the Makefile at build
 865          * time.
 866          */
 867         setup_path();
 868
 869         while (1) {
 870                 int was_alias = run_argv(&argc, &argv);
 871                 if (errno != ENOENT)
 872                         break;
 873                 if (was_alias) {
 874                         fprintf(stderr, _("expansion of alias '%s' failed; "
 875                                           "'%s' is not a git command\n"),
 876                                 cmd, argv[0]);
 877                         exit(1);
 878                 }
 879                 if (!done_help) {
 880                         cmd = argv[0] = help_unknown_cmd(cmd);
 881                         done_help = 1;
 882                 } else
 883                         break;
 884         }
 885
 886         fprintf(stderr, _("failed to run command '%s': %s\n"),
 887                 cmd, strerror(errno));
 888
 889         return 1;
 890 }