Andrew's git / gitweb.git / git.c
?
git.con commit git-instaweb: add Python builtin http.server support (2eb14bb)
   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{
 103        switch (use_pager) {
 104        case 0:
 105                setenv("GIT_PAGER", "cat", 1);
 106                break;
 107        case 1:
 108                setup_pager();
 109                break;
 110        default:
 111                break;
 112        }
 113}
 114
 115void setup_auto_pager(const char *cmd, int def)
 116{
 117        if (use_pager != -1 || pager_in_use())
 118                return;
 119        use_pager = check_pager_config(cmd);
 120        if (use_pager == -1)
 121                use_pager = def;
 122        commit_pager_choice();
 123}
 124
 125static int handle_options(const char ***argv, int *argc, int *envchanged)
 126{
 127        const char **orig_argv = *argv;
 128
 129        while (*argc > 0) {
 130                const char *cmd = (*argv)[0];
 131                if (cmd[0] != '-')
 132                        break;
 133
 134                /*
 135                 * For legacy reasons, the "version" and "help"
 136                 * commands can be written with "--" prepended
 137                 * to make them look like flags.
 138                 */
 139                if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
 140                        break;
 141
 142                /*
 143                 * Check remaining flags.
 144                 */
 145                if (skip_prefix(cmd, "--exec-path", &cmd)) {
 146                        if (*cmd == '=')
 147                                git_set_exec_path(cmd + 1);
 148                        else {
 149                                puts(git_exec_path());
 150                                exit(0);
 151                        }
 152                } else if (!strcmp(cmd, "--html-path")) {
 153                        puts(system_path(GIT_HTML_PATH));
 154                        exit(0);
 155                } else if (!strcmp(cmd, "--man-path")) {
 156                        puts(system_path(GIT_MAN_PATH));
 157                        exit(0);
 158                } else if (!strcmp(cmd, "--info-path")) {
 159                        puts(system_path(GIT_INFO_PATH));
 160                        exit(0);
 161                } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 162                        use_pager = 1;
 163                } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
 164                        use_pager = 0;
 165                        if (envchanged)
 166                                *envchanged = 1;
 167                } else if (!strcmp(cmd, "--no-replace-objects")) {
 168                        read_replace_refs = 0;
 169                        setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 170                        if (envchanged)
 171                                *envchanged = 1;
 172                } else if (!strcmp(cmd, "--git-dir")) {
 173                        if (*argc < 2) {
 174                                fprintf(stderr, _("no directory given for --git-dir\n" ));
 175                                usage(git_usage_string);
 176                        }
 177                        setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 178                        if (envchanged)
 179                                *envchanged = 1;
 180                        (*argv)++;
 181                        (*argc)--;
 182                } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 183                        setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 184                        if (envchanged)
 185                                *envchanged = 1;
 186                } else if (!strcmp(cmd, "--namespace")) {
 187                        if (*argc < 2) {
 188                                fprintf(stderr, _("no namespace given for --namespace\n" ));
 189                                usage(git_usage_string);
 190                        }
 191                        setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 192                        if (envchanged)
 193                                *envchanged = 1;
 194                        (*argv)++;
 195                        (*argc)--;
 196                } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 197                        setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 198                        if (envchanged)
 199                                *envchanged = 1;
 200                } else if (!strcmp(cmd, "--work-tree")) {
 201                        if (*argc < 2) {
 202                                fprintf(stderr, _("no directory given for --work-tree\n" ));
 203                                usage(git_usage_string);
 204                        }
 205                        setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 206                        if (envchanged)
 207                                *envchanged = 1;
 208                        (*argv)++;
 209                        (*argc)--;
 210                } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 211                        setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 212                        if (envchanged)
 213                                *envchanged = 1;
 214                } else if (!strcmp(cmd, "--super-prefix")) {
 215                        if (*argc < 2) {
 216                                fprintf(stderr, _("no prefix given for --super-prefix\n" ));
 217                                usage(git_usage_string);
 218                        }
 219                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 220                        if (envchanged)
 221                                *envchanged = 1;
 222                        (*argv)++;
 223                        (*argc)--;
 224                } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 225                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 226                        if (envchanged)
 227                                *envchanged = 1;
 228                } else if (!strcmp(cmd, "--bare")) {
 229                        char *cwd = xgetcwd();
 230                        is_bare_repository_cfg = 1;
 231                        setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 232                        free(cwd);
 233                        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 234                        if (envchanged)
 235                                *envchanged = 1;
 236                } else if (!strcmp(cmd, "-c")) {
 237                        if (*argc < 2) {
 238                                fprintf(stderr, _("-c expects a configuration string\n" ));
 239                                usage(git_usage_string);
 240                        }
 241                        git_config_push_parameter((*argv)[1]);
 242                        (*argv)++;
 243                        (*argc)--;
 244                } else if (!strcmp(cmd, "--literal-pathspecs")) {
 245                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 246                        if (envchanged)
 247                                *envchanged = 1;
 248                } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 249                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 250                        if (envchanged)
 251                                *envchanged = 1;
 252                } else if (!strcmp(cmd, "--glob-pathspecs")) {
 253                        setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 254                        if (envchanged)
 255                                *envchanged = 1;
 256                } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 257                        setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 258                        if (envchanged)
 259                                *envchanged = 1;
 260                } else if (!strcmp(cmd, "--icase-pathspecs")) {
 261                        setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 262                        if (envchanged)
 263                                *envchanged = 1;
 264                } else if (!strcmp(cmd, "--no-optional-locks")) {
 265                        setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 266                        if (envchanged)
 267                                *envchanged = 1;
 268                } else if (!strcmp(cmd, "--shallow-file")) {
 269                        (*argv)++;
 270                        (*argc)--;
 271                        set_alternate_shallow_file(the_repository, (*argv)[0], 1);
 272                        if (envchanged)
 273                                *envchanged = 1;
 274                } else if (!strcmp(cmd, "-C")) {
 275                        if (*argc < 2) {
 276                                fprintf(stderr, _("no directory given for -C\n" ));
 277                                usage(git_usage_string);
 278                        }
 279                        if ((*argv)[1][0]) {
 280                                if (chdir((*argv)[1]))
 281                                        die_errno("cannot change to '%s'", (*argv)[1]);
 282                                if (envchanged)
 283                                        *envchanged = 1;
 284                        }
 285                        (*argv)++;
 286                        (*argc)--;
 287                } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 288                        if (!strcmp(cmd, "parseopt")) {
 289                                struct string_list list = STRING_LIST_INIT_DUP;
 290                                int i;
 291
 292                                list_builtins(&list, NO_PARSEOPT);
 293                                for (i = 0; i < list.nr; i++)
 294                                        printf("%s ", list.items[i].string);
 295                                string_list_clear(&list, 0);
 296                                exit(0);
 297                        } else {
 298                                exit(list_cmds(cmd));
 299                        }
 300                } else {
 301                        fprintf(stderr, _("unknown option: %s\n"), cmd);
 302                        usage(git_usage_string);
 303                }
 304
 305                (*argv)++;
 306                (*argc)--;
 307        }
 308        return (*argv) - orig_argv;
 309}
 310
 311static int handle_alias(int *argcp, const char ***argv)
 312{
 313        int envchanged = 0, ret = 0, saved_errno = errno;
 314        int count, option_count;
 315        const char **new_argv;
 316        const char *alias_command;
 317        char *alias_string;
 318
 319        alias_command = (*argv)[0];
 320        alias_string = alias_lookup(alias_command);
 321        if (alias_string) {
 322                if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
 323                        fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
 324                                   alias_command, alias_string);
 325                if (alias_string[0] == '!') {
 326                        struct child_process child = CHILD_PROCESS_INIT;
 327                        int nongit_ok;
 328
 329                        /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 330                        setup_git_directory_gently(&nongit_ok);
 331
 332                        commit_pager_choice();
 333
 334                        child.use_shell = 1;
 335                        argv_array_push(&child.args, alias_string + 1);
 336                        argv_array_pushv(&child.args, (*argv) + 1);
 337
 338                        ret = run_command(&child);
 339                        if (ret >= 0)   /* normal exit */
 340                                exit(ret);
 341
 342                        die_errno(_("while expanding alias '%s': '%s'"),
 343                                  alias_command, alias_string + 1);
 344                }
 345                count = split_cmdline(alias_string, &new_argv);
 346                if (count < 0)
 347                        die(_("bad alias.%s string: %s"), alias_command,
 348                            _(split_cmdline_strerror(count)));
 349                option_count = handle_options(&new_argv, &count, &envchanged);
 350                if (envchanged)
 351                        die(_("alias '%s' changes environment variables.\n"
 352                              "You can use '!git' in the alias to do this"),
 353                            alias_command);
 354                memmove(new_argv - option_count, new_argv,
 355                                count * sizeof(char *));
 356                new_argv -= option_count;
 357
 358                if (count < 1)
 359                        die(_("empty alias for %s"), alias_command);
 360
 361                if (!strcmp(alias_command, new_argv[0]))
 362                        die(_("recursive alias: %s"), alias_command);
 363
 364                trace_argv_printf(new_argv,
 365                                  "trace: alias expansion: %s =>",
 366                                  alias_command);
 367
 368                REALLOC_ARRAY(new_argv, count + *argcp);
 369                /* insert after command name */
 370                memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 371
 372                *argv = new_argv;
 373                *argcp += count - 1;
 374
 375                ret = 1;
 376        }
 377
 378        errno = saved_errno;
 379
 380        return ret;
 381}
 382
 383static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 384{
 385        int status, help;
 386        struct stat st;
 387        const char *prefix;
 388
 389        prefix = NULL;
 390        help = argc == 2 && !strcmp(argv[1], "-h");
 391        if (!help) {
 392                if (p->option & RUN_SETUP)
 393                        prefix = setup_git_directory();
 394                else if (p->option & RUN_SETUP_GENTLY) {
 395                        int nongit_ok;
 396                        prefix = setup_git_directory_gently(&nongit_ok);
 397                }
 398
 399                if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
 400                    !(p->option & DELAY_PAGER_CONFIG))
 401                        use_pager = check_pager_config(p->cmd);
 402                if (use_pager == -1 && p->option & USE_PAGER)
 403                        use_pager = 1;
 404
 405                if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 406                    startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 407                        trace_repo_setup(prefix);
 408        }
 409        commit_pager_choice();
 410
 411        if (!help && get_super_prefix()) {
 412                if (!(p->option & SUPPORT_SUPER_PREFIX))
 413                        die(_("%s doesn't support --super-prefix"), p->cmd);
 414        }
 415
 416        if (!help && p->option & NEED_WORK_TREE)
 417                setup_work_tree();
 418
 419        trace_argv_printf(argv, "trace: built-in: git");
 420
 421        validate_cache_entries(&the_index);
 422        status = p->fn(argc, argv, prefix);
 423        validate_cache_entries(&the_index);
 424
 425        if (status)
 426                return status;
 427
 428        /* Somebody closed stdout? */
 429        if (fstat(fileno(stdout), &st))
 430                return 0;
 431        /* Ignore write errors for pipes and sockets.. */
 432        if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 433                return 0;
 434
 435        /* Check for ENOSPC and EIO errors.. */
 436        if (fflush(stdout))
 437                die_errno(_("write failure on standard output"));
 438        if (ferror(stdout))
 439                die(_("unknown write failure on standard output"));
 440        if (fclose(stdout))
 441                die_errno(_("close failed on standard output"));
 442        return 0;
 443}
 444
 445static struct cmd_struct commands[] = {
 446        { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 447        { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 448        { "annotate", cmd_annotate, RUN_SETUP | NO_PARSEOPT },
 449        { "apply", cmd_apply, RUN_SETUP_GENTLY },
 450        { "archive", cmd_archive, RUN_SETUP_GENTLY },
 451        { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 452        { "blame", cmd_blame, RUN_SETUP },
 453        { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 454        { "bundle", cmd_bundle, RUN_SETUP_GENTLY | NO_PARSEOPT },
 455        { "cat-file", cmd_cat_file, RUN_SETUP },
 456        { "check-attr", cmd_check_attr, RUN_SETUP },
 457        { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 458        { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 459        { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 460        { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 461        { "checkout-index", cmd_checkout_index,
 462                RUN_SETUP | NEED_WORK_TREE},
 463        { "cherry", cmd_cherry, RUN_SETUP },
 464        { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 465        { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 466        { "clone", cmd_clone },
 467        { "column", cmd_column, RUN_SETUP_GENTLY },
 468        { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 469        { "commit-graph", cmd_commit_graph, RUN_SETUP },
 470        { "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
 471        { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 472        { "count-objects", cmd_count_objects, RUN_SETUP },
 473        { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 474        { "describe", cmd_describe, RUN_SETUP },
 475        { "diff", cmd_diff, NO_PARSEOPT },
 476        { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 477        { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 478        { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 479        { "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
 480        { "fast-export", cmd_fast_export, RUN_SETUP },
 481        { "fetch", cmd_fetch, RUN_SETUP },
 482        { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 483        { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 484        { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 485        { "format-patch", cmd_format_patch, RUN_SETUP },
 486        { "fsck", cmd_fsck, RUN_SETUP },
 487        { "fsck-objects", cmd_fsck, RUN_SETUP },
 488        { "gc", cmd_gc, RUN_SETUP },
 489        { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 490        { "grep", cmd_grep, RUN_SETUP_GENTLY },
 491        { "hash-object", cmd_hash_object },
 492        { "help", cmd_help },
 493        { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 494        { "init", cmd_init_db },
 495        { "init-db", cmd_init_db },
 496        { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 497        { "log", cmd_log, RUN_SETUP },
 498        { "ls-files", cmd_ls_files, RUN_SETUP },
 499        { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 500        { "ls-tree", cmd_ls_tree, RUN_SETUP },
 501        { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY | NO_PARSEOPT },
 502        { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 503        { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 504        { "merge-base", cmd_merge_base, RUN_SETUP },
 505        { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 506        { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 507        { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 508        { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 509        { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 510        { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 511        { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 512        { "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
 513        { "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
 514        { "mktree", cmd_mktree, RUN_SETUP },
 515        { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP_GENTLY },
 516        { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 517        { "name-rev", cmd_name_rev, RUN_SETUP },
 518        { "notes", cmd_notes, RUN_SETUP },
 519        { "pack-objects", cmd_pack_objects, RUN_SETUP },
 520        { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 521        { "pack-refs", cmd_pack_refs, RUN_SETUP },
 522        { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 523        { "pickaxe", cmd_blame, RUN_SETUP },
 524        { "prune", cmd_prune, RUN_SETUP },
 525        { "prune-packed", cmd_prune_packed, RUN_SETUP },
 526        { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 527        { "push", cmd_push, RUN_SETUP },
 528        { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
 529        { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 530        /*
 531         * NEEDSWORK: Until the rebase is independent and needs no redirection
 532         * to rebase shell script this is kept as is, then should be changed to
 533         * RUN_SETUP | NEED_WORK_TREE
 534         */
 535        { "rebase", cmd_rebase },
 536        { "rebase--interactive", cmd_rebase__interactive, RUN_SETUP | NEED_WORK_TREE },
 537        { "receive-pack", cmd_receive_pack },
 538        { "reflog", cmd_reflog, RUN_SETUP },
 539        { "remote", cmd_remote, RUN_SETUP },
 540        { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 541        { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 542        { "repack", cmd_repack, RUN_SETUP },
 543        { "replace", cmd_replace, RUN_SETUP },
 544        { "rerere", cmd_rerere, RUN_SETUP },
 545        { "reset", cmd_reset, RUN_SETUP },
 546        { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 547        { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 548        { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 549        { "rm", cmd_rm, RUN_SETUP },
 550        { "send-pack", cmd_send_pack, RUN_SETUP },
 551        { "serve", cmd_serve, RUN_SETUP },
 552        { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 553        { "show", cmd_show, RUN_SETUP },
 554        { "show-branch", cmd_show_branch, RUN_SETUP },
 555        { "show-index", cmd_show_index },
 556        { "show-ref", cmd_show_ref, RUN_SETUP },
 557        { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 558        { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 559        { "stripspace", cmd_stripspace },
 560        { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
 561        { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 562        { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 563        { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 564        { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 565        { "update-index", cmd_update_index, RUN_SETUP },
 566        { "update-ref", cmd_update_ref, RUN_SETUP },
 567        { "update-server-info", cmd_update_server_info, RUN_SETUP },
 568        { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 569        { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 570        { "upload-pack", cmd_upload_pack },
 571        { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 572        { "verify-commit", cmd_verify_commit, RUN_SETUP },
 573        { "verify-pack", cmd_verify_pack },
 574        { "verify-tag", cmd_verify_tag, RUN_SETUP },
 575        { "version", cmd_version },
 576        { "whatchanged", cmd_whatchanged, RUN_SETUP },
 577        { "worktree", cmd_worktree, RUN_SETUP | NO_PARSEOPT },
 578        { "write-tree", cmd_write_tree, RUN_SETUP },
 579};
 580
 581static struct cmd_struct *get_builtin(const char *s)
 582{
 583        int i;
 584        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 585                struct cmd_struct *p = commands + i;
 586                if (!strcmp(s, p->cmd))
 587                        return p;
 588        }
 589        return NULL;
 590}
 591
 592int is_builtin(const char *s)
 593{
 594        return !!get_builtin(s);
 595}
 596
 597static void list_builtins(struct string_list *out, unsigned int exclude_option)
 598{
 599        int i;
 600        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 601                if (exclude_option &&
 602                    (commands[i].option & exclude_option))
 603                        continue;
 604                string_list_append(out, commands[i].cmd);
 605        }
 606}
 607
 608#ifdef STRIP_EXTENSION
 609static void strip_extension(const char **argv)
 610{
 611        size_t len;
 612
 613        if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 614                argv[0] = xmemdupz(argv[0], len);
 615}
 616#else
 617#define strip_extension(cmd)
 618#endif
 619
 620static void handle_builtin(int argc, const char **argv)
 621{
 622        struct argv_array args = ARGV_ARRAY_INIT;
 623        const char *cmd;
 624        struct cmd_struct *builtin;
 625
 626        strip_extension(argv);
 627        cmd = argv[0];
 628
 629        /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 630        if (argc > 1 && !strcmp(argv[1], "--help")) {
 631                int i;
 632
 633                argv[1] = argv[0];
 634                argv[0] = cmd = "help";
 635
 636                for (i = 0; i < argc; i++) {
 637                        argv_array_push(&args, argv[i]);
 638                        if (!i)
 639                                argv_array_push(&args, "--exclude-guides");
 640                }
 641
 642                argc++;
 643                argv = args.argv;
 644        }
 645
 646        builtin = get_builtin(cmd);
 647        if (builtin)
 648                exit(run_builtin(builtin, argc, argv));
 649        argv_array_clear(&args);
 650}
 651
 652static void execv_dashed_external(const char **argv)
 653{
 654        struct child_process cmd = CHILD_PROCESS_INIT;
 655        int status;
 656
 657        if (get_super_prefix())
 658                die(_("%s doesn't support --super-prefix"), argv[0]);
 659
 660        if (use_pager == -1 && !is_builtin(argv[0]))
 661                use_pager = check_pager_config(argv[0]);
 662        commit_pager_choice();
 663
 664        argv_array_pushf(&cmd.args, "git-%s", argv[0]);
 665        argv_array_pushv(&cmd.args, argv + 1);
 666        cmd.clean_on_exit = 1;
 667        cmd.wait_after_clean = 1;
 668        cmd.silent_exec_failure = 1;
 669
 670        trace_argv_printf(cmd.args.argv, "trace: exec:");
 671
 672        /*
 673         * If we fail because the command is not found, it is
 674         * OK to return. Otherwise, we just pass along the status code,
 675         * or our usual generic code if we were not even able to exec
 676         * the program.
 677         */
 678        status = run_command(&cmd);
 679        if (status >= 0)
 680                exit(status);
 681        else if (errno != ENOENT)
 682                exit(128);
 683}
 684
 685static int run_argv(int *argcp, const char ***argv)
 686{
 687        int done_alias = 0;
 688        struct string_list cmd_list = STRING_LIST_INIT_NODUP;
 689        struct string_list_item *seen;
 690
 691        while (1) {
 692                /*
 693                 * If we tried alias and futzed with our environment,
 694                 * it no longer is safe to invoke builtins directly in
 695                 * general.  We have to spawn them as dashed externals.
 696                 *
 697                 * NEEDSWORK: if we can figure out cases
 698                 * where it is safe to do, we can avoid spawning a new
 699                 * process.
 700                 */
 701                if (!done_alias)
 702                        handle_builtin(*argcp, *argv);
 703
 704                /* .. then try the external ones */
 705                execv_dashed_external(*argv);
 706
 707                seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
 708                if (seen) {
 709                        int i;
 710                        struct strbuf sb = STRBUF_INIT;
 711                        for (i = 0; i < cmd_list.nr; i++) {
 712                                struct string_list_item *item = &cmd_list.items[i];
 713
 714                                strbuf_addf(&sb, "\n  %s", item->string);
 715                                if (item == seen)
 716                                        strbuf_addstr(&sb, " <==");
 717                                else if (i == cmd_list.nr - 1)
 718                                        strbuf_addstr(&sb, " ==>");
 719                        }
 720                        die(_("alias loop detected: expansion of '%s' does"
 721                              " not terminate:%s"), cmd_list.items[0].string, sb.buf);
 722                }
 723
 724                string_list_append(&cmd_list, *argv[0]);
 725
 726                /*
 727                 * It could be an alias -- this works around the insanity
 728                 * of overriding "git log" with "git show" by having
 729                 * alias.log = show
 730                 */
 731                if (!handle_alias(argcp, argv))
 732                        break;
 733                done_alias = 1;
 734        }
 735
 736        string_list_clear(&cmd_list, 0);
 737
 738        return done_alias;
 739}
 740
 741int cmd_main(int argc, const char **argv)
 742{
 743        const char *cmd;
 744        int done_help = 0;
 745
 746        cmd = argv[0];
 747        if (!cmd)
 748                cmd = "git-help";
 749        else {
 750                const char *slash = find_last_dir_sep(cmd);
 751                if (slash)
 752                        cmd = slash + 1;
 753        }
 754
 755        trace_command_performance(argv);
 756
 757        /*
 758         * "git-xxxx" is the same as "git xxxx", but we obviously:
 759         *
 760         *  - cannot take flags in between the "git" and the "xxxx".
 761         *  - cannot execute it externally (since it would just do
 762         *    the same thing over again)
 763         *
 764         * So we just directly call the builtin handler, and die if
 765         * that one cannot handle it.
 766         */
 767        if (skip_prefix(cmd, "git-", &cmd)) {
 768                argv[0] = cmd;
 769                handle_builtin(argc, argv);
 770                die(_("cannot handle %s as a builtin"), cmd);
 771        }
 772
 773        /* Look for flags.. */
 774        argv++;
 775        argc--;
 776        handle_options(&argv, &argc, NULL);
 777        if (argc > 0) {
 778                /* translate --help and --version into commands */
 779                skip_prefix(argv[0], "--", &argv[0]);
 780        } else {
 781                /* The user didn't specify a command; give them help */
 782                commit_pager_choice();
 783                printf(_("usage: %s\n\n"), git_usage_string);
 784                list_common_cmds_help();
 785                printf("\n%s\n", _(git_more_info_string));
 786                exit(1);
 787        }
 788        cmd = argv[0];
 789
 790        /*
 791         * We use PATH to find git commands, but we prepend some higher
 792         * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 793         * environment, and the $(gitexecdir) from the Makefile at build
 794         * time.
 795         */
 796        setup_path();
 797
 798        while (1) {
 799                int was_alias = run_argv(&argc, &argv);
 800                if (errno != ENOENT)
 801                        break;
 802                if (was_alias) {
 803                        fprintf(stderr, _("expansion of alias '%s' failed; "
 804                                          "'%s' is not a git command\n"),
 805                                cmd, argv[0]);
 806                        exit(1);
 807                }
 808                if (!done_help) {
 809                        cmd = argv[0] = help_unknown_cmd(cmd);
 810                        done_help = 1;
 811                } else
 812                        break;
 813        }
 814
 815        fprintf(stderr, _("failed to run command '%s': %s\n"),
 816                cmd, strerror(errno));
 817
 818        return 1;
 819}