git.con commit Merge branch 'rs/strbuf-cocci-workaround' (73df1b3)
   1#include "builtin.h"
   2#include "config.h"
   3#include "exec_cmd.h"
   4#include "help.h"
   5#include "run-command.h"
   6
   7const char git_usage_string[] =
   8        "git [--version] [--help] [-C <path>] [-c name=value]\n"
   9        "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  10        "           [-p | --paginate | --no-pager] [--no-replace-objects] [--bare]\n"
  11        "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  12        "           <command> [<args>]";
  13
  14const char git_more_info_string[] =
  15        N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  16           "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  17           "to read about a specific subcommand or concept.");
  18
  19static int use_pager = -1;
  20
  21static void list_builtins(void);
  22
  23static void commit_pager_choice(void) {
  24        switch (use_pager) {
  25        case 0:
  26                setenv("GIT_PAGER", "cat", 1);
  27                break;
  28        case 1:
  29                setup_pager();
  30                break;
  31        default:
  32                break;
  33        }
  34}
  35
  36void setup_auto_pager(const char *cmd, int def)
  37{
  38        if (use_pager != -1 || pager_in_use())
  39                return;
  40        use_pager = check_pager_config(cmd);
  41        if (use_pager == -1)
  42                use_pager = def;
  43        commit_pager_choice();
  44}
  45
  46static int handle_options(const char ***argv, int *argc, int *envchanged)
  47{
  48        const char **orig_argv = *argv;
  49
  50        while (*argc > 0) {
  51                const char *cmd = (*argv)[0];
  52                if (cmd[0] != '-')
  53                        break;
  54
  55                /*
  56                 * For legacy reasons, the "version" and "help"
  57                 * commands can be written with "--" prepended
  58                 * to make them look like flags.
  59                 */
  60                if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  61                        break;
  62
  63                /*
  64                 * Check remaining flags.
  65                 */
  66                if (skip_prefix(cmd, "--exec-path", &cmd)) {
  67                        if (*cmd == '=')
  68                                git_set_argv_exec_path(cmd + 1);
  69                        else {
  70                                puts(git_exec_path());
  71                                exit(0);
  72                        }
  73                } else if (!strcmp(cmd, "--html-path")) {
  74                        puts(system_path(GIT_HTML_PATH));
  75                        exit(0);
  76                } else if (!strcmp(cmd, "--man-path")) {
  77                        puts(system_path(GIT_MAN_PATH));
  78                        exit(0);
  79                } else if (!strcmp(cmd, "--info-path")) {
  80                        puts(system_path(GIT_INFO_PATH));
  81                        exit(0);
  82                } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
  83                        use_pager = 1;
  84                } else if (!strcmp(cmd, "--no-pager")) {
  85                        use_pager = 0;
  86                        if (envchanged)
  87                                *envchanged = 1;
  88                } else if (!strcmp(cmd, "--no-replace-objects")) {
  89                        check_replace_refs = 0;
  90                        setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
  91                        if (envchanged)
  92                                *envchanged = 1;
  93                } else if (!strcmp(cmd, "--git-dir")) {
  94                        if (*argc < 2) {
  95                                fprintf(stderr, "No directory given for --git-dir.\n" );
  96                                usage(git_usage_string);
  97                        }
  98                        setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
  99                        if (envchanged)
 100                                *envchanged = 1;
 101                        (*argv)++;
 102                        (*argc)--;
 103                } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 104                        setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 105                        if (envchanged)
 106                                *envchanged = 1;
 107                } else if (!strcmp(cmd, "--namespace")) {
 108                        if (*argc < 2) {
 109                                fprintf(stderr, "No namespace given for --namespace.\n" );
 110                                usage(git_usage_string);
 111                        }
 112                        setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 113                        if (envchanged)
 114                                *envchanged = 1;
 115                        (*argv)++;
 116                        (*argc)--;
 117                } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 118                        setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 119                        if (envchanged)
 120                                *envchanged = 1;
 121                } else if (!strcmp(cmd, "--work-tree")) {
 122                        if (*argc < 2) {
 123                                fprintf(stderr, "No directory given for --work-tree.\n" );
 124                                usage(git_usage_string);
 125                        }
 126                        setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 127                        if (envchanged)
 128                                *envchanged = 1;
 129                        (*argv)++;
 130                        (*argc)--;
 131                } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 132                        setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 133                        if (envchanged)
 134                                *envchanged = 1;
 135                } else if (!strcmp(cmd, "--super-prefix")) {
 136                        if (*argc < 2) {
 137                                fprintf(stderr, "No prefix given for --super-prefix.\n" );
 138                                usage(git_usage_string);
 139                        }
 140                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 141                        if (envchanged)
 142                                *envchanged = 1;
 143                        (*argv)++;
 144                        (*argc)--;
 145                } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 146                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 147                        if (envchanged)
 148                                *envchanged = 1;
 149                } else if (!strcmp(cmd, "--bare")) {
 150                        char *cwd = xgetcwd();
 151                        is_bare_repository_cfg = 1;
 152                        setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 153                        free(cwd);
 154                        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 155                        if (envchanged)
 156                                *envchanged = 1;
 157                } else if (!strcmp(cmd, "-c")) {
 158                        if (*argc < 2) {
 159                                fprintf(stderr, "-c expects a configuration string\n" );
 160                                usage(git_usage_string);
 161                        }
 162                        git_config_push_parameter((*argv)[1]);
 163                        (*argv)++;
 164                        (*argc)--;
 165                } else if (!strcmp(cmd, "--literal-pathspecs")) {
 166                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 167                        if (envchanged)
 168                                *envchanged = 1;
 169                } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 170                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 171                        if (envchanged)
 172                                *envchanged = 1;
 173                } else if (!strcmp(cmd, "--glob-pathspecs")) {
 174                        setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 175                        if (envchanged)
 176                                *envchanged = 1;
 177                } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 178                        setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 179                        if (envchanged)
 180                                *envchanged = 1;
 181                } else if (!strcmp(cmd, "--icase-pathspecs")) {
 182                        setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 183                        if (envchanged)
 184                                *envchanged = 1;
 185                } else if (!strcmp(cmd, "--no-optional-locks")) {
 186                        setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 187                        if (envchanged)
 188                                *envchanged = 1;
 189                } else if (!strcmp(cmd, "--shallow-file")) {
 190                        (*argv)++;
 191                        (*argc)--;
 192                        set_alternate_shallow_file((*argv)[0], 1);
 193                        if (envchanged)
 194                                *envchanged = 1;
 195                } else if (!strcmp(cmd, "-C")) {
 196                        if (*argc < 2) {
 197                                fprintf(stderr, "No directory given for -C.\n" );
 198                                usage(git_usage_string);
 199                        }
 200                        if ((*argv)[1][0]) {
 201                                if (chdir((*argv)[1]))
 202                                        die_errno("Cannot change to '%s'", (*argv)[1]);
 203                                if (envchanged)
 204                                        *envchanged = 1;
 205                        }
 206                        (*argv)++;
 207                        (*argc)--;
 208                } else if (!strcmp(cmd, "--list-builtins")) {
 209                        list_builtins();
 210                        exit(0);
 211                } else {
 212                        fprintf(stderr, "Unknown option: %s\n", cmd);
 213                        usage(git_usage_string);
 214                }
 215
 216                (*argv)++;
 217                (*argc)--;
 218        }
 219        return (*argv) - orig_argv;
 220}
 221
 222static int handle_alias(int *argcp, const char ***argv)
 223{
 224        int envchanged = 0, ret = 0, saved_errno = errno;
 225        int count, option_count;
 226        const char **new_argv;
 227        const char *alias_command;
 228        char *alias_string;
 229
 230        alias_command = (*argv)[0];
 231        alias_string = alias_lookup(alias_command);
 232        if (alias_string) {
 233                if (alias_string[0] == '!') {
 234                        struct child_process child = CHILD_PROCESS_INIT;
 235                        int nongit_ok;
 236
 237                        /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 238                        setup_git_directory_gently(&nongit_ok);
 239
 240                        commit_pager_choice();
 241
 242                        child.use_shell = 1;
 243                        argv_array_push(&child.args, alias_string + 1);
 244                        argv_array_pushv(&child.args, (*argv) + 1);
 245
 246                        ret = run_command(&child);
 247                        if (ret >= 0)   /* normal exit */
 248                                exit(ret);
 249
 250                        die_errno("While expanding alias '%s': '%s'",
 251                            alias_command, alias_string + 1);
 252                }
 253                count = split_cmdline(alias_string, &new_argv);
 254                if (count < 0)
 255                        die("Bad alias.%s string: %s", alias_command,
 256                            split_cmdline_strerror(count));
 257                option_count = handle_options(&new_argv, &count, &envchanged);
 258                if (envchanged)
 259                        die("alias '%s' changes environment variables\n"
 260                                 "You can use '!git' in the alias to do this.",
 261                                 alias_command);
 262                memmove(new_argv - option_count, new_argv,
 263                                count * sizeof(char *));
 264                new_argv -= option_count;
 265
 266                if (count < 1)
 267                        die("empty alias for %s", alias_command);
 268
 269                if (!strcmp(alias_command, new_argv[0]))
 270                        die("recursive alias: %s", alias_command);
 271
 272                trace_argv_printf(new_argv,
 273                                  "trace: alias expansion: %s =>",
 274                                  alias_command);
 275
 276                REALLOC_ARRAY(new_argv, count + *argcp);
 277                /* insert after command name */
 278                memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 279
 280                *argv = new_argv;
 281                *argcp += count - 1;
 282
 283                ret = 1;
 284        }
 285
 286        errno = saved_errno;
 287
 288        return ret;
 289}
 290
 291#define RUN_SETUP               (1<<0)
 292#define RUN_SETUP_GENTLY        (1<<1)
 293#define USE_PAGER               (1<<2)
 294/*
 295 * require working tree to be present -- anything uses this needs
 296 * RUN_SETUP for reading from the configuration file.
 297 */
 298#define NEED_WORK_TREE          (1<<3)
 299#define SUPPORT_SUPER_PREFIX    (1<<4)
 300#define DELAY_PAGER_CONFIG      (1<<5)
 301
 302struct cmd_struct {
 303        const char *cmd;
 304        int (*fn)(int, const char **, const char *);
 305        int option;
 306};
 307
 308static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 309{
 310        int status, help;
 311        struct stat st;
 312        const char *prefix;
 313
 314        prefix = NULL;
 315        help = argc == 2 && !strcmp(argv[1], "-h");
 316        if (!help) {
 317                if (p->option & RUN_SETUP)
 318                        prefix = setup_git_directory();
 319                else if (p->option & RUN_SETUP_GENTLY) {
 320                        int nongit_ok;
 321                        prefix = setup_git_directory_gently(&nongit_ok);
 322                }
 323
 324                if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
 325                    !(p->option & DELAY_PAGER_CONFIG))
 326                        use_pager = check_pager_config(p->cmd);
 327                if (use_pager == -1 && p->option & USE_PAGER)
 328                        use_pager = 1;
 329
 330                if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 331                    startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 332                        trace_repo_setup(prefix);
 333        }
 334        commit_pager_choice();
 335
 336        if (!help && get_super_prefix()) {
 337                if (!(p->option & SUPPORT_SUPER_PREFIX))
 338                        die("%s doesn't support --super-prefix", p->cmd);
 339        }
 340
 341        if (!help && p->option & NEED_WORK_TREE)
 342                setup_work_tree();
 343
 344        trace_argv_printf(argv, "trace: built-in: git");
 345
 346        status = p->fn(argc, argv, prefix);
 347        if (status)
 348                return status;
 349
 350        /* Somebody closed stdout? */
 351        if (fstat(fileno(stdout), &st))
 352                return 0;
 353        /* Ignore write errors for pipes and sockets.. */
 354        if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 355                return 0;
 356
 357        /* Check for ENOSPC and EIO errors.. */
 358        if (fflush(stdout))
 359                die_errno("write failure on standard output");
 360        if (ferror(stdout))
 361                die("unknown write failure on standard output");
 362        if (fclose(stdout))
 363                die_errno("close failed on standard output");
 364        return 0;
 365}
 366
 367static struct cmd_struct commands[] = {
 368        { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 369        { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 370        { "annotate", cmd_annotate, RUN_SETUP },
 371        { "apply", cmd_apply, RUN_SETUP_GENTLY },
 372        { "archive", cmd_archive, RUN_SETUP_GENTLY },
 373        { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 374        { "blame", cmd_blame, RUN_SETUP },
 375        { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 376        { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 377        { "cat-file", cmd_cat_file, RUN_SETUP },
 378        { "check-attr", cmd_check_attr, RUN_SETUP },
 379        { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 380        { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 381        { "check-ref-format", cmd_check_ref_format },
 382        { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 383        { "checkout-index", cmd_checkout_index,
 384                RUN_SETUP | NEED_WORK_TREE},
 385        { "cherry", cmd_cherry, RUN_SETUP },
 386        { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 387        { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 388        { "clone", cmd_clone },
 389        { "column", cmd_column, RUN_SETUP_GENTLY },
 390        { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 391        { "commit-tree", cmd_commit_tree, RUN_SETUP },
 392        { "config", cmd_config, RUN_SETUP_GENTLY },
 393        { "count-objects", cmd_count_objects, RUN_SETUP },
 394        { "credential", cmd_credential, RUN_SETUP_GENTLY },
 395        { "describe", cmd_describe, RUN_SETUP },
 396        { "diff", cmd_diff },
 397        { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 398        { "diff-index", cmd_diff_index, RUN_SETUP },
 399        { "diff-tree", cmd_diff_tree, RUN_SETUP },
 400        { "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
 401        { "fast-export", cmd_fast_export, RUN_SETUP },
 402        { "fetch", cmd_fetch, RUN_SETUP },
 403        { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
 404        { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 405        { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 406        { "format-patch", cmd_format_patch, RUN_SETUP },
 407        { "fsck", cmd_fsck, RUN_SETUP },
 408        { "fsck-objects", cmd_fsck, RUN_SETUP },
 409        { "gc", cmd_gc, RUN_SETUP },
 410        { "get-tar-commit-id", cmd_get_tar_commit_id },
 411        { "grep", cmd_grep, RUN_SETUP_GENTLY },
 412        { "hash-object", cmd_hash_object },
 413        { "help", cmd_help },
 414        { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
 415        { "init", cmd_init_db },
 416        { "init-db", cmd_init_db },
 417        { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 418        { "log", cmd_log, RUN_SETUP },
 419        { "ls-files", cmd_ls_files, RUN_SETUP },
 420        { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 421        { "ls-tree", cmd_ls_tree, RUN_SETUP },
 422        { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
 423        { "mailsplit", cmd_mailsplit },
 424        { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 425        { "merge-base", cmd_merge_base, RUN_SETUP },
 426        { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 427        { "merge-index", cmd_merge_index, RUN_SETUP },
 428        { "merge-ours", cmd_merge_ours, RUN_SETUP },
 429        { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 430        { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 431        { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 432        { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 433        { "merge-tree", cmd_merge_tree, RUN_SETUP },
 434        { "mktag", cmd_mktag, RUN_SETUP },
 435        { "mktree", cmd_mktree, RUN_SETUP },
 436        { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 437        { "name-rev", cmd_name_rev, RUN_SETUP },
 438        { "notes", cmd_notes, RUN_SETUP },
 439        { "pack-objects", cmd_pack_objects, RUN_SETUP },
 440        { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
 441        { "pack-refs", cmd_pack_refs, RUN_SETUP },
 442        { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY },
 443        { "pickaxe", cmd_blame, RUN_SETUP },
 444        { "prune", cmd_prune, RUN_SETUP },
 445        { "prune-packed", cmd_prune_packed, RUN_SETUP },
 446        { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 447        { "push", cmd_push, RUN_SETUP },
 448        { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 449        { "rebase--helper", cmd_rebase__helper, RUN_SETUP | NEED_WORK_TREE },
 450        { "receive-pack", cmd_receive_pack },
 451        { "reflog", cmd_reflog, RUN_SETUP },
 452        { "remote", cmd_remote, RUN_SETUP },
 453        { "remote-ext", cmd_remote_ext },
 454        { "remote-fd", cmd_remote_fd },
 455        { "repack", cmd_repack, RUN_SETUP },
 456        { "replace", cmd_replace, RUN_SETUP },
 457        { "rerere", cmd_rerere, RUN_SETUP },
 458        { "reset", cmd_reset, RUN_SETUP },
 459        { "rev-list", cmd_rev_list, RUN_SETUP },
 460        { "rev-parse", cmd_rev_parse },
 461        { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 462        { "rm", cmd_rm, RUN_SETUP },
 463        { "send-pack", cmd_send_pack, RUN_SETUP },
 464        { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 465        { "show", cmd_show, RUN_SETUP },
 466        { "show-branch", cmd_show_branch, RUN_SETUP },
 467        { "show-ref", cmd_show_ref, RUN_SETUP },
 468        { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 469        { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 470        { "stripspace", cmd_stripspace },
 471        { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 472        { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 473        { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 474        { "unpack-file", cmd_unpack_file, RUN_SETUP },
 475        { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 476        { "update-index", cmd_update_index, RUN_SETUP },
 477        { "update-ref", cmd_update_ref, RUN_SETUP },
 478        { "update-server-info", cmd_update_server_info, RUN_SETUP },
 479        { "upload-archive", cmd_upload_archive },
 480        { "upload-archive--writer", cmd_upload_archive_writer },
 481        { "var", cmd_var, RUN_SETUP_GENTLY },
 482        { "verify-commit", cmd_verify_commit, RUN_SETUP },
 483        { "verify-pack", cmd_verify_pack },
 484        { "verify-tag", cmd_verify_tag, RUN_SETUP },
 485        { "version", cmd_version },
 486        { "whatchanged", cmd_whatchanged, RUN_SETUP },
 487        { "worktree", cmd_worktree, RUN_SETUP },
 488        { "write-tree", cmd_write_tree, RUN_SETUP },
 489};
 490
 491static struct cmd_struct *get_builtin(const char *s)
 492{
 493        int i;
 494        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 495                struct cmd_struct *p = commands + i;
 496                if (!strcmp(s, p->cmd))
 497                        return p;
 498        }
 499        return NULL;
 500}
 501
 502int is_builtin(const char *s)
 503{
 504        return !!get_builtin(s);
 505}
 506
 507static void list_builtins(void)
 508{
 509        int i;
 510        for (i = 0; i < ARRAY_SIZE(commands); i++)
 511                printf("%s\n", commands[i].cmd);
 512}
 513
 514#ifdef STRIP_EXTENSION
 515static void strip_extension(const char **argv)
 516{
 517        size_t len;
 518
 519        if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 520                argv[0] = xmemdupz(argv[0], len);
 521}
 522#else
 523#define strip_extension(cmd)
 524#endif
 525
 526static void handle_builtin(int argc, const char **argv)
 527{
 528        struct argv_array args = ARGV_ARRAY_INIT;
 529        const char *cmd;
 530        struct cmd_struct *builtin;
 531
 532        strip_extension(argv);
 533        cmd = argv[0];
 534
 535        /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 536        if (argc > 1 && !strcmp(argv[1], "--help")) {
 537                int i;
 538
 539                argv[1] = argv[0];
 540                argv[0] = cmd = "help";
 541
 542                for (i = 0; i < argc; i++) {
 543                        argv_array_push(&args, argv[i]);
 544                        if (!i)
 545                                argv_array_push(&args, "--exclude-guides");
 546                }
 547
 548                argc++;
 549                argv = args.argv;
 550        }
 551
 552        builtin = get_builtin(cmd);
 553        if (builtin)
 554                exit(run_builtin(builtin, argc, argv));
 555        argv_array_clear(&args);
 556}
 557
 558static void execv_dashed_external(const char **argv)
 559{
 560        struct child_process cmd = CHILD_PROCESS_INIT;
 561        int status;
 562
 563        if (get_super_prefix())
 564                die("%s doesn't support --super-prefix", argv[0]);
 565
 566        if (use_pager == -1 && !is_builtin(argv[0]))
 567                use_pager = check_pager_config(argv[0]);
 568        commit_pager_choice();
 569
 570        argv_array_pushf(&cmd.args, "git-%s", argv[0]);
 571        argv_array_pushv(&cmd.args, argv + 1);
 572        cmd.clean_on_exit = 1;
 573        cmd.wait_after_clean = 1;
 574        cmd.silent_exec_failure = 1;
 575
 576        trace_argv_printf(cmd.args.argv, "trace: exec:");
 577
 578        /*
 579         * If we fail because the command is not found, it is
 580         * OK to return. Otherwise, we just pass along the status code,
 581         * or our usual generic code if we were not even able to exec
 582         * the program.
 583         */
 584        status = run_command(&cmd);
 585        if (status >= 0)
 586                exit(status);
 587        else if (errno != ENOENT)
 588                exit(128);
 589}
 590
 591static int run_argv(int *argcp, const char ***argv)
 592{
 593        int done_alias = 0;
 594
 595        while (1) {
 596                /*
 597                 * If we tried alias and futzed with our environment,
 598                 * it no longer is safe to invoke builtins directly in
 599                 * general.  We have to spawn them as dashed externals.
 600                 *
 601                 * NEEDSWORK: if we can figure out cases
 602                 * where it is safe to do, we can avoid spawning a new
 603                 * process.
 604                 */
 605                if (!done_alias)
 606                        handle_builtin(*argcp, *argv);
 607
 608                /* .. then try the external ones */
 609                execv_dashed_external(*argv);
 610
 611                /* It could be an alias -- this works around the insanity
 612                 * of overriding "git log" with "git show" by having
 613                 * alias.log = show
 614                 */
 615                if (done_alias)
 616                        break;
 617                if (!handle_alias(argcp, argv))
 618                        break;
 619                done_alias = 1;
 620        }
 621
 622        return done_alias;
 623}
 624
 625int cmd_main(int argc, const char **argv)
 626{
 627        const char *cmd;
 628        int done_help = 0;
 629
 630        cmd = argv[0];
 631        if (!cmd)
 632                cmd = "git-help";
 633        else {
 634                const char *slash = find_last_dir_sep(cmd);
 635                if (slash)
 636                        cmd = slash + 1;
 637        }
 638
 639        trace_command_performance(argv);
 640
 641        /*
 642         * "git-xxxx" is the same as "git xxxx", but we obviously:
 643         *
 644         *  - cannot take flags in between the "git" and the "xxxx".
 645         *  - cannot execute it externally (since it would just do
 646         *    the same thing over again)
 647         *
 648         * So we just directly call the builtin handler, and die if
 649         * that one cannot handle it.
 650         */
 651        if (skip_prefix(cmd, "git-", &cmd)) {
 652                argv[0] = cmd;
 653                handle_builtin(argc, argv);
 654                die("cannot handle %s as a builtin", cmd);
 655        }
 656
 657        /* Look for flags.. */
 658        argv++;
 659        argc--;
 660        handle_options(&argv, &argc, NULL);
 661        if (argc > 0) {
 662                /* translate --help and --version into commands */
 663                skip_prefix(argv[0], "--", &argv[0]);
 664        } else {
 665                /* The user didn't specify a command; give them help */
 666                commit_pager_choice();
 667                printf("usage: %s\n\n", git_usage_string);
 668                list_common_cmds_help();
 669                printf("\n%s\n", _(git_more_info_string));
 670                exit(1);
 671        }
 672        cmd = argv[0];
 673
 674        /*
 675         * We use PATH to find git commands, but we prepend some higher
 676         * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 677         * environment, and the $(gitexecdir) from the Makefile at build
 678         * time.
 679         */
 680        setup_path();
 681
 682        while (1) {
 683                int was_alias = run_argv(&argc, &argv);
 684                if (errno != ENOENT)
 685                        break;
 686                if (was_alias) {
 687                        fprintf(stderr, "Expansion of alias '%s' failed; "
 688                                "'%s' is not a git command\n",
 689                                cmd, argv[0]);
 690                        exit(1);
 691                }
 692                if (!done_help) {
 693                        cmd = argv[0] = help_unknown_cmd(cmd);
 694                        done_help = 1;
 695                } else
 696                        break;
 697        }
 698
 699        fprintf(stderr, "Failed to run command '%s': %s\n",
 700                cmd, strerror(errno));
 701
 702        return 1;
 703}