Andrew's git / gitweb.git / git.c
?
git.con commit banned.h: mark strncat() as banned (ace5707)
   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
  20struct cmd_struct {
  21        const char *cmd;
  22        int (*fn)(int, const char **, const char *);
  23        unsigned int option;
  24};
  25
  26const 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
  33const 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.");
  37
  38static int use_pager = -1;
  39
  40static void list_builtins(struct string_list *list, unsigned int exclude_option);
  41
  42static void exclude_helpers_from_list(struct string_list *list)
  43{
  44        int i = 0;
  45
  46        while (i < list->nr) {
  47                if (strstr(list->items[i].string, "--"))
  48                        unsorted_string_list_delete_item(list, i, 0);
  49                else
  50                        i++;
  51        }
  52}
  53
  54static int match_token(const char *spec, int len, const char *token)
  55{
  56        int token_len = strlen(token);
  57
  58        return len == token_len && !strncmp(spec, token, token_len);
  59}
  60
  61static int list_cmds(const char *spec)
  62{
  63        struct string_list list = STRING_LIST_INIT_DUP;
  64        int i;
  65
  66        while (*spec) {
  67                const char *sep = strchrnul(spec, ',');
  68                int len = sep - spec;
  69
  70                if (match_token(spec, len, "builtins"))
  71                        list_builtins(&list, 0);
  72                else if (match_token(spec, len, "main"))
  73                        list_all_main_cmds(&list);
  74                else if (match_token(spec, len, "others"))
  75                        list_all_other_cmds(&list);
  76                else if (match_token(spec, len, "nohelpers"))
  77                        exclude_helpers_from_list(&list);
  78                else if (match_token(spec, len, "alias"))
  79                        list_aliases(&list);
  80                else if (match_token(spec, len, "config"))
  81                        list_cmds_by_config(&list);
  82                else if (len > 5 && !strncmp(spec, "list-", 5)) {
  83                        struct strbuf sb = STRBUF_INIT;
  84
  85                        strbuf_add(&sb, spec + 5, len - 5);
  86                        list_cmds_by_category(&list, sb.buf);
  87                        strbuf_release(&sb);
  88                }
  89                else
  90                        die(_("unsupported command listing type '%s'"), spec);
  91                spec += len;
  92                if (*spec == ',')
  93                        spec++;
  94        }
  95        for (i = 0; i < list.nr; i++)
  96                puts(list.items[i].string);
  97        string_list_clear(&list, 0);
  98        return 0;
  99}
 100
 101static void commit_pager_choice(void) {
 102        switch (use_pager) {
 103        case 0:
 104                setenv("GIT_PAGER", "cat", 1);
 105                break;
 106        case 1:
 107                setup_pager();
 108                break;
 109        default:
 110                break;
 111        }
 112}
 113
 114void setup_auto_pager(const char *cmd, int def)
 115{
 116        if (use_pager != -1 || pager_in_use())
 117                return;
 118        use_pager = check_pager_config(cmd);
 119        if (use_pager == -1)
 120                use_pager = def;
 121        commit_pager_choice();
 122}
 123
 124static int handle_options(const char ***argv, int *argc, int *envchanged)
 125{
 126        const char **orig_argv = *argv;
 127
 128        while (*argc > 0) {
 129                const char *cmd = (*argv)[0];
 130                if (cmd[0] != '-')
 131                        break;
 132
 133                /*
 134                 * For legacy reasons, the "version" and "help"
 135                 * commands can be written with "--" prepended
 136                 * to make them look like flags.
 137                 */
 138                if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
 139                        break;
 140
 141                /*
 142                 * Check remaining flags.
 143                 */
 144                if (skip_prefix(cmd, "--exec-path", &cmd)) {
 145                        if (*cmd == '=')
 146                                git_set_exec_path(cmd + 1);
 147                        else {
 148                                puts(git_exec_path());
 149                                exit(0);
 150                        }
 151                } else if (!strcmp(cmd, "--html-path")) {
 152                        puts(system_path(GIT_HTML_PATH));
 153                        exit(0);
 154                } else if (!strcmp(cmd, "--man-path")) {
 155                        puts(system_path(GIT_MAN_PATH));
 156                        exit(0);
 157                } else if (!strcmp(cmd, "--info-path")) {
 158                        puts(system_path(GIT_INFO_PATH));
 159                        exit(0);
 160                } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 161                        use_pager = 1;
 162                } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
 163                        use_pager = 0;
 164                        if (envchanged)
 165                                *envchanged = 1;
 166                } else if (!strcmp(cmd, "--no-replace-objects")) {
 167                        read_replace_refs = 0;
 168                        setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 169                        if (envchanged)
 170                                *envchanged = 1;
 171                } else if (!strcmp(cmd, "--git-dir")) {
 172                        if (*argc < 2) {
 173                                fprintf(stderr, _("no directory given for --git-dir\n" ));
 174                                usage(git_usage_string);
 175                        }
 176                        setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 177                        if (envchanged)
 178                                *envchanged = 1;
 179                        (*argv)++;
 180                        (*argc)--;
 181                } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 182                        setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 183                        if (envchanged)
 184                                *envchanged = 1;
 185                } else if (!strcmp(cmd, "--namespace")) {
 186                        if (*argc < 2) {
 187                                fprintf(stderr, _("no namespace given for --namespace\n" ));
 188                                usage(git_usage_string);
 189                        }
 190                        setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 191                        if (envchanged)
 192                                *envchanged = 1;
 193                        (*argv)++;
 194                        (*argc)--;
 195                } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 196                        setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 197                        if (envchanged)
 198                                *envchanged = 1;
 199                } else if (!strcmp(cmd, "--work-tree")) {
 200                        if (*argc < 2) {
 201                                fprintf(stderr, _("no directory given for --work-tree\n" ));
 202                                usage(git_usage_string);
 203                        }
 204                        setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 205                        if (envchanged)
 206                                *envchanged = 1;
 207                        (*argv)++;
 208                        (*argc)--;
 209                } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 210                        setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 211                        if (envchanged)
 212                                *envchanged = 1;
 213                } else if (!strcmp(cmd, "--super-prefix")) {
 214                        if (*argc < 2) {
 215                                fprintf(stderr, _("no prefix given for --super-prefix\n" ));
 216                                usage(git_usage_string);
 217                        }
 218                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 219                        if (envchanged)
 220                                *envchanged = 1;
 221                        (*argv)++;
 222                        (*argc)--;
 223                } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 224                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 225                        if (envchanged)
 226                                *envchanged = 1;
 227                } else if (!strcmp(cmd, "--bare")) {
 228                        char *cwd = xgetcwd();
 229                        is_bare_repository_cfg = 1;
 230                        setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 231                        free(cwd);
 232                        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 233                        if (envchanged)
 234                                *envchanged = 1;
 235                } else if (!strcmp(cmd, "-c")) {
 236                        if (*argc < 2) {
 237                                fprintf(stderr, _("-c expects a configuration string\n" ));
 238                                usage(git_usage_string);
 239                        }
 240                        git_config_push_parameter((*argv)[1]);
 241                        (*argv)++;
 242                        (*argc)--;
 243                } else if (!strcmp(cmd, "--literal-pathspecs")) {
 244                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 245                        if (envchanged)
 246                                *envchanged = 1;
 247                } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 248                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 249                        if (envchanged)
 250                                *envchanged = 1;
 251                } else if (!strcmp(cmd, "--glob-pathspecs")) {
 252                        setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 253                        if (envchanged)
 254                                *envchanged = 1;
 255                } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 256                        setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 257                        if (envchanged)
 258                                *envchanged = 1;
 259                } else if (!strcmp(cmd, "--icase-pathspecs")) {
 260                        setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 261                        if (envchanged)
 262                                *envchanged = 1;
 263                } else if (!strcmp(cmd, "--no-optional-locks")) {
 264                        setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 265                        if (envchanged)
 266                                *envchanged = 1;
 267                } else if (!strcmp(cmd, "--shallow-file")) {
 268                        (*argv)++;
 269                        (*argc)--;
 270                        set_alternate_shallow_file(the_repository, (*argv)[0], 1);
 271                        if (envchanged)
 272                                *envchanged = 1;
 273                } else if (!strcmp(cmd, "-C")) {
 274                        if (*argc < 2) {
 275                                fprintf(stderr, _("no directory given for -C\n" ));
 276                                usage(git_usage_string);
 277                        }
 278                        if ((*argv)[1][0]) {
 279                                if (chdir((*argv)[1]))
 280                                        die_errno("cannot change to '%s'", (*argv)[1]);
 281                                if (envchanged)
 282                                        *envchanged = 1;
 283                        }
 284                        (*argv)++;
 285                        (*argc)--;
 286                } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 287                        if (!strcmp(cmd, "parseopt")) {
 288                                struct string_list list = STRING_LIST_INIT_DUP;
 289                                int i;
 290
 291                                list_builtins(&list, NO_PARSEOPT);
 292                                for (i = 0; i < list.nr; i++)
 293                                        printf("%s ", list.items[i].string);
 294                                string_list_clear(&list, 0);
 295                                exit(0);
 296                        } else {
 297                                exit(list_cmds(cmd));
 298                        }
 299                } else {
 300                        fprintf(stderr, _("unknown option: %s\n"), cmd);
 301                        usage(git_usage_string);
 302                }
 303
 304                (*argv)++;
 305                (*argc)--;
 306        }
 307        return (*argv) - orig_argv;
 308}
 309
 310static int handle_alias(int *argcp, const char ***argv)
 311{
 312        int envchanged = 0, ret = 0, saved_errno = errno;
 313        int count, option_count;
 314        const char **new_argv;
 315        const char *alias_command;
 316        char *alias_string;
 317
 318        alias_command = (*argv)[0];
 319        alias_string = alias_lookup(alias_command);
 320        if (alias_string) {
 321                if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
 322                        fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
 323                                   alias_command, alias_string);
 324                if (alias_string[0] == '!') {
 325                        struct child_process child = CHILD_PROCESS_INIT;
 326                        int nongit_ok;
 327
 328                        /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 329                        setup_git_directory_gently(&nongit_ok);
 330
 331                        commit_pager_choice();
 332
 333                        child.use_shell = 1;
 334                        argv_array_push(&child.args, alias_string + 1);
 335                        argv_array_pushv(&child.args, (*argv) + 1);
 336
 337                        ret = run_command(&child);
 338                        if (ret >= 0)   /* normal exit */
 339                                exit(ret);
 340
 341                        die_errno("while expanding alias '%s': '%s'",
 342                            alias_command, alias_string + 1);
 343                }
 344                count = split_cmdline(alias_string, &new_argv);
 345                if (count < 0)
 346                        die("Bad alias.%s string: %s", alias_command,
 347                            split_cmdline_strerror(count));
 348                option_count = handle_options(&new_argv, &count, &envchanged);
 349                if (envchanged)
 350                        die("alias '%s' changes environment variables.\n"
 351                                 "You can use '!git' in the alias to do this",
 352                                 alias_command);
 353                memmove(new_argv - option_count, new_argv,
 354                                count * sizeof(char *));
 355                new_argv -= option_count;
 356
 357                if (count < 1)
 358                        die("empty alias for %s", alias_command);
 359
 360                if (!strcmp(alias_command, new_argv[0]))
 361                        die("recursive alias: %s", alias_command);
 362
 363                trace_argv_printf(new_argv,
 364                                  "trace: alias expansion: %s =>",
 365                                  alias_command);
 366
 367                REALLOC_ARRAY(new_argv, count + *argcp);
 368                /* insert after command name */
 369                memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 370
 371                *argv = new_argv;
 372                *argcp += count - 1;
 373
 374                ret = 1;
 375        }
 376
 377        errno = saved_errno;
 378
 379        return ret;
 380}
 381
 382static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 383{
 384        int status, help;
 385        struct stat st;
 386        const char *prefix;
 387
 388        prefix = NULL;
 389        help = argc == 2 && !strcmp(argv[1], "-h");
 390        if (!help) {
 391                if (p->option & RUN_SETUP)
 392                        prefix = setup_git_directory();
 393                else if (p->option & RUN_SETUP_GENTLY) {
 394                        int nongit_ok;
 395                        prefix = setup_git_directory_gently(&nongit_ok);
 396                }
 397
 398                if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
 399                    !(p->option & DELAY_PAGER_CONFIG))
 400                        use_pager = check_pager_config(p->cmd);
 401                if (use_pager == -1 && p->option & USE_PAGER)
 402                        use_pager = 1;
 403
 404                if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 405                    startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 406                        trace_repo_setup(prefix);
 407        }
 408        commit_pager_choice();
 409
 410        if (!help && get_super_prefix()) {
 411                if (!(p->option & SUPPORT_SUPER_PREFIX))
 412                        die("%s doesn't support --super-prefix", p->cmd);
 413        }
 414
 415        if (!help && p->option & NEED_WORK_TREE)
 416                setup_work_tree();
 417
 418        trace_argv_printf(argv, "trace: built-in: git");
 419
 420        validate_cache_entries(&the_index);
 421        status = p->fn(argc, argv, prefix);
 422        validate_cache_entries(&the_index);
 423
 424        if (status)
 425                return status;
 426
 427        /* Somebody closed stdout? */
 428        if (fstat(fileno(stdout), &st))
 429                return 0;
 430        /* Ignore write errors for pipes and sockets.. */
 431        if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 432                return 0;
 433
 434        /* Check for ENOSPC and EIO errors.. */
 435        if (fflush(stdout))
 436                die_errno("write failure on standard output");
 437        if (ferror(stdout))
 438                die("unknown write failure on standard output");
 439        if (fclose(stdout))
 440                die_errno("close failed on standard output");
 441        return 0;
 442}
 443
 444static struct cmd_struct commands[] = {
 445        { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 446        { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 447        { "annotate", cmd_annotate, RUN_SETUP | NO_PARSEOPT },
 448        { "apply", cmd_apply, RUN_SETUP_GENTLY },
 449        { "archive", cmd_archive, RUN_SETUP_GENTLY },
 450        { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 451        { "blame", cmd_blame, RUN_SETUP },
 452        { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 453        { "bundle", cmd_bundle, RUN_SETUP_GENTLY | NO_PARSEOPT },
 454        { "cat-file", cmd_cat_file, RUN_SETUP },
 455        { "check-attr", cmd_check_attr, RUN_SETUP },
 456        { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 457        { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 458        { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 459        { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 460        { "checkout-index", cmd_checkout_index,
 461                RUN_SETUP | NEED_WORK_TREE},
 462        { "cherry", cmd_cherry, RUN_SETUP },
 463        { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 464        { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 465        { "clone", cmd_clone },
 466        { "column", cmd_column, RUN_SETUP_GENTLY },
 467        { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 468        { "commit-graph", cmd_commit_graph, RUN_SETUP },
 469        { "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
 470        { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 471        { "count-objects", cmd_count_objects, RUN_SETUP },
 472        { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 473        { "describe", cmd_describe, RUN_SETUP },
 474        { "diff", cmd_diff, NO_PARSEOPT },
 475        { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 476        { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 477        { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 478        { "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
 479        { "fast-export", cmd_fast_export, RUN_SETUP },
 480        { "fetch", cmd_fetch, RUN_SETUP },
 481        { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 482        { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 483        { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 484        { "format-patch", cmd_format_patch, RUN_SETUP },
 485        { "fsck", cmd_fsck, RUN_SETUP },
 486        { "fsck-objects", cmd_fsck, RUN_SETUP },
 487        { "gc", cmd_gc, RUN_SETUP },
 488        { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 489        { "grep", cmd_grep, RUN_SETUP_GENTLY },
 490        { "hash-object", cmd_hash_object },
 491        { "help", cmd_help },
 492        { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 493        { "init", cmd_init_db },
 494        { "init-db", cmd_init_db },
 495        { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 496        { "log", cmd_log, RUN_SETUP },
 497        { "ls-files", cmd_ls_files, RUN_SETUP },
 498        { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 499        { "ls-tree", cmd_ls_tree, RUN_SETUP },
 500        { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY | NO_PARSEOPT },
 501        { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 502        { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 503        { "merge-base", cmd_merge_base, RUN_SETUP },
 504        { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 505        { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 506        { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 507        { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 508        { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 509        { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 510        { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 511        { "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
 512        { "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
 513        { "mktree", cmd_mktree, RUN_SETUP },
 514        { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP_GENTLY },
 515        { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 516        { "name-rev", cmd_name_rev, RUN_SETUP },
 517        { "notes", cmd_notes, RUN_SETUP },
 518        { "pack-objects", cmd_pack_objects, RUN_SETUP },
 519        { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 520        { "pack-refs", cmd_pack_refs, RUN_SETUP },
 521        { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 522        { "pickaxe", cmd_blame, RUN_SETUP },
 523        { "prune", cmd_prune, RUN_SETUP },
 524        { "prune-packed", cmd_prune_packed, RUN_SETUP },
 525        { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 526        { "push", cmd_push, RUN_SETUP },
 527        { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
 528        { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 529        /*
 530         * NEEDSWORK: Until the rebase is independent and needs no redirection
 531         * to rebase shell script this is kept as is, then should be changed to
 532         * RUN_SETUP | NEED_WORK_TREE
 533         */
 534        { "rebase", cmd_rebase },
 535        { "rebase--interactive", cmd_rebase__interactive, RUN_SETUP | NEED_WORK_TREE },
 536        { "receive-pack", cmd_receive_pack },
 537        { "reflog", cmd_reflog, RUN_SETUP },
 538        { "remote", cmd_remote, RUN_SETUP },
 539        { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 540        { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 541        { "repack", cmd_repack, RUN_SETUP },
 542        { "replace", cmd_replace, RUN_SETUP },
 543        { "rerere", cmd_rerere, RUN_SETUP },
 544        { "reset", cmd_reset, RUN_SETUP },
 545        { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 546        { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 547        { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 548        { "rm", cmd_rm, RUN_SETUP },
 549        { "send-pack", cmd_send_pack, RUN_SETUP },
 550        { "serve", cmd_serve, RUN_SETUP },
 551        { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 552        { "show", cmd_show, RUN_SETUP },
 553        { "show-branch", cmd_show_branch, RUN_SETUP },
 554        { "show-index", cmd_show_index },
 555        { "show-ref", cmd_show_ref, RUN_SETUP },
 556        { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 557        { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 558        { "stripspace", cmd_stripspace },
 559        { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
 560        { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 561        { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 562        { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 563        { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 564        { "update-index", cmd_update_index, RUN_SETUP },
 565        { "update-ref", cmd_update_ref, RUN_SETUP },
 566        { "update-server-info", cmd_update_server_info, RUN_SETUP },
 567        { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 568        { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 569        { "upload-pack", cmd_upload_pack },
 570        { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 571        { "verify-commit", cmd_verify_commit, RUN_SETUP },
 572        { "verify-pack", cmd_verify_pack },
 573        { "verify-tag", cmd_verify_tag, RUN_SETUP },
 574        { "version", cmd_version },
 575        { "whatchanged", cmd_whatchanged, RUN_SETUP },
 576        { "worktree", cmd_worktree, RUN_SETUP | NO_PARSEOPT },
 577        { "write-tree", cmd_write_tree, RUN_SETUP },
 578};
 579
 580static struct cmd_struct *get_builtin(const char *s)
 581{
 582        int i;
 583        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 584                struct cmd_struct *p = commands + i;
 585                if (!strcmp(s, p->cmd))
 586                        return p;
 587        }
 588        return NULL;
 589}
 590
 591int is_builtin(const char *s)
 592{
 593        return !!get_builtin(s);
 594}
 595
 596static void list_builtins(struct string_list *out, unsigned int exclude_option)
 597{
 598        int i;
 599        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 600                if (exclude_option &&
 601                    (commands[i].option & exclude_option))
 602                        continue;
 603                string_list_append(out, commands[i].cmd);
 604        }
 605}
 606
 607#ifdef STRIP_EXTENSION
 608static void strip_extension(const char **argv)
 609{
 610        size_t len;
 611
 612        if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 613                argv[0] = xmemdupz(argv[0], len);
 614}
 615#else
 616#define strip_extension(cmd)
 617#endif
 618
 619static void handle_builtin(int argc, const char **argv)
 620{
 621        struct argv_array args = ARGV_ARRAY_INIT;
 622        const char *cmd;
 623        struct cmd_struct *builtin;
 624
 625        strip_extension(argv);
 626        cmd = argv[0];
 627
 628        /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 629        if (argc > 1 && !strcmp(argv[1], "--help")) {
 630                int i;
 631
 632                argv[1] = argv[0];
 633                argv[0] = cmd = "help";
 634
 635                for (i = 0; i < argc; i++) {
 636                        argv_array_push(&args, argv[i]);
 637                        if (!i)
 638                                argv_array_push(&args, "--exclude-guides");
 639                }
 640
 641                argc++;
 642                argv = args.argv;
 643        }
 644
 645        builtin = get_builtin(cmd);
 646        if (builtin)
 647                exit(run_builtin(builtin, argc, argv));
 648        argv_array_clear(&args);
 649}
 650
 651static void execv_dashed_external(const char **argv)
 652{
 653        struct child_process cmd = CHILD_PROCESS_INIT;
 654        int status;
 655
 656        if (get_super_prefix())
 657                die("%s doesn't support --super-prefix", argv[0]);
 658
 659        if (use_pager == -1 && !is_builtin(argv[0]))
 660                use_pager = check_pager_config(argv[0]);
 661        commit_pager_choice();
 662
 663        argv_array_pushf(&cmd.args, "git-%s", argv[0]);
 664        argv_array_pushv(&cmd.args, argv + 1);
 665        cmd.clean_on_exit = 1;
 666        cmd.wait_after_clean = 1;
 667        cmd.silent_exec_failure = 1;
 668
 669        trace_argv_printf(cmd.args.argv, "trace: exec:");
 670
 671        /*
 672         * If we fail because the command is not found, it is
 673         * OK to return. Otherwise, we just pass along the status code,
 674         * or our usual generic code if we were not even able to exec
 675         * the program.
 676         */
 677        status = run_command(&cmd);
 678        if (status >= 0)
 679                exit(status);
 680        else if (errno != ENOENT)
 681                exit(128);
 682}
 683
 684static int run_argv(int *argcp, const char ***argv)
 685{
 686        int done_alias = 0;
 687        struct string_list cmd_list = STRING_LIST_INIT_NODUP;
 688        struct string_list_item *seen;
 689
 690        while (1) {
 691                /*
 692                 * If we tried alias and futzed with our environment,
 693                 * it no longer is safe to invoke builtins directly in
 694                 * general.  We have to spawn them as dashed externals.
 695                 *
 696                 * NEEDSWORK: if we can figure out cases
 697                 * where it is safe to do, we can avoid spawning a new
 698                 * process.
 699                 */
 700                if (!done_alias)
 701                        handle_builtin(*argcp, *argv);
 702
 703                /* .. then try the external ones */
 704                execv_dashed_external(*argv);
 705
 706                seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
 707                if (seen) {
 708                        int i;
 709                        struct strbuf sb = STRBUF_INIT;
 710                        for (i = 0; i < cmd_list.nr; i++) {
 711                                struct string_list_item *item = &cmd_list.items[i];
 712
 713                                strbuf_addf(&sb, "\n  %s", item->string);
 714                                if (item == seen)
 715                                        strbuf_addstr(&sb, " <==");
 716                                else if (i == cmd_list.nr - 1)
 717                                        strbuf_addstr(&sb, " ==>");
 718                        }
 719                        die(_("alias loop detected: expansion of '%s' does"
 720                              " not terminate:%s"), cmd_list.items[0].string, sb.buf);
 721                }
 722
 723                string_list_append(&cmd_list, *argv[0]);
 724
 725                /*
 726                 * It could be an alias -- this works around the insanity
 727                 * of overriding "git log" with "git show" by having
 728                 * alias.log = show
 729                 */
 730                if (!handle_alias(argcp, argv))
 731                        break;
 732                done_alias = 1;
 733        }
 734
 735        string_list_clear(&cmd_list, 0);
 736
 737        return done_alias;
 738}
 739
 740int cmd_main(int argc, const char **argv)
 741{
 742        const char *cmd;
 743        int done_help = 0;
 744
 745        cmd = argv[0];
 746        if (!cmd)
 747                cmd = "git-help";
 748        else {
 749                const char *slash = find_last_dir_sep(cmd);
 750                if (slash)
 751                        cmd = slash + 1;
 752        }
 753
 754        trace_command_performance(argv);
 755
 756        /*
 757         * "git-xxxx" is the same as "git xxxx", but we obviously:
 758         *
 759         *  - cannot take flags in between the "git" and the "xxxx".
 760         *  - cannot execute it externally (since it would just do
 761         *    the same thing over again)
 762         *
 763         * So we just directly call the builtin handler, and die if
 764         * that one cannot handle it.
 765         */
 766        if (skip_prefix(cmd, "git-", &cmd)) {
 767                argv[0] = cmd;
 768                handle_builtin(argc, argv);
 769                die("cannot handle %s as a builtin", cmd);
 770        }
 771
 772        /* Look for flags.. */
 773        argv++;
 774        argc--;
 775        handle_options(&argv, &argc, NULL);
 776        if (argc > 0) {
 777                /* translate --help and --version into commands */
 778                skip_prefix(argv[0], "--", &argv[0]);
 779        } else {
 780                /* The user didn't specify a command; give them help */
 781                commit_pager_choice();
 782                printf("usage: %s\n\n", git_usage_string);
 783                list_common_cmds_help();
 784                printf("\n%s\n", _(git_more_info_string));
 785                exit(1);
 786        }
 787        cmd = argv[0];
 788
 789        /*
 790         * We use PATH to find git commands, but we prepend some higher
 791         * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 792         * environment, and the $(gitexecdir) from the Makefile at build
 793         * time.
 794         */
 795        setup_path();
 796
 797        while (1) {
 798                int was_alias = run_argv(&argc, &argv);
 799                if (errno != ENOENT)
 800                        break;
 801                if (was_alias) {
 802                        fprintf(stderr, _("expansion of alias '%s' failed; "
 803                                          "'%s' is not a git command\n"),
 804                                cmd, argv[0]);
 805                        exit(1);
 806                }
 807                if (!done_help) {
 808                        cmd = argv[0] = help_unknown_cmd(cmd);
 809                        done_help = 1;
 810                } else
 811                        break;
 812        }
 813
 814        fprintf(stderr, _("failed to run command '%s': %s\n"),
 815                cmd, strerror(errno));
 816
 817        return 1;
 818}