git.con commit index-pack: smarter memory usage when resolving deltas (776ea37)
   1#include "builtin.h"
   2#include "exec_cmd.h"
   3#include "cache.h"
   4#include "quote.h"
   5#include "run-command.h"
   6
   7const char git_usage_string[] =
   8        "git [--version] [--exec-path[=GIT_EXEC_PATH]] [--html-path]\n"
   9        "           [-p|--paginate|--no-pager] [--no-replace-objects]\n"
  10        "           [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE]\n"
  11        "           [--help] COMMAND [ARGS]";
  12
  13const char git_more_info_string[] =
  14        "See 'git help COMMAND' for more information on a specific command.";
  15
  16static int use_pager = -1;
  17struct pager_config {
  18        const char *cmd;
  19        int val;
  20};
  21
  22static int pager_command_config(const char *var, const char *value, void *data)
  23{
  24        struct pager_config *c = data;
  25        if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
  26                c->val = git_config_bool(var, value);
  27        return 0;
  28}
  29
  30/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
  31int check_pager_config(const char *cmd)
  32{
  33        struct pager_config c;
  34        c.cmd = cmd;
  35        c.val = -1;
  36        git_config(pager_command_config, &c);
  37        return c.val;
  38}
  39
  40static void commit_pager_choice(void) {
  41        switch (use_pager) {
  42        case 0:
  43                setenv("GIT_PAGER", "cat", 1);
  44                break;
  45        case 1:
  46                setup_pager();
  47                break;
  48        default:
  49                break;
  50        }
  51}
  52
  53static int handle_options(const char ***argv, int *argc, int *envchanged)
  54{
  55        int handled = 0;
  56
  57        while (*argc > 0) {
  58                const char *cmd = (*argv)[0];
  59                if (cmd[0] != '-')
  60                        break;
  61
  62                /*
  63                 * For legacy reasons, the "version" and "help"
  64                 * commands can be written with "--" prepended
  65                 * to make them look like flags.
  66                 */
  67                if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  68                        break;
  69
  70                /*
  71                 * Check remaining flags.
  72                 */
  73                if (!prefixcmp(cmd, "--exec-path")) {
  74                        cmd += 11;
  75                        if (*cmd == '=')
  76                                git_set_argv_exec_path(cmd + 1);
  77                        else {
  78                                puts(git_exec_path());
  79                                exit(0);
  80                        }
  81                } else if (!strcmp(cmd, "--html-path")) {
  82                        puts(system_path(GIT_HTML_PATH));
  83                        exit(0);
  84                } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
  85                        use_pager = 1;
  86                } else if (!strcmp(cmd, "--no-pager")) {
  87                        use_pager = 0;
  88                        if (envchanged)
  89                                *envchanged = 1;
  90                } else if (!strcmp(cmd, "--no-replace-objects")) {
  91                        read_replace_refs = 0;
  92                        setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
  93                        if (envchanged)
  94                                *envchanged = 1;
  95                } else if (!strcmp(cmd, "--git-dir")) {
  96                        if (*argc < 2) {
  97                                fprintf(stderr, "No directory given for --git-dir.\n" );
  98                                usage(git_usage_string);
  99                        }
 100                        setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 101                        if (envchanged)
 102                                *envchanged = 1;
 103                        (*argv)++;
 104                        (*argc)--;
 105                        handled++;
 106                } else if (!prefixcmp(cmd, "--git-dir=")) {
 107                        setenv(GIT_DIR_ENVIRONMENT, cmd + 10, 1);
 108                        if (envchanged)
 109                                *envchanged = 1;
 110                } else if (!strcmp(cmd, "--work-tree")) {
 111                        if (*argc < 2) {
 112                                fprintf(stderr, "No directory given for --work-tree.\n" );
 113                                usage(git_usage_string);
 114                        }
 115                        setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 116                        if (envchanged)
 117                                *envchanged = 1;
 118                        (*argv)++;
 119                        (*argc)--;
 120                } else if (!prefixcmp(cmd, "--work-tree=")) {
 121                        setenv(GIT_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
 122                        if (envchanged)
 123                                *envchanged = 1;
 124                } else if (!strcmp(cmd, "--bare")) {
 125                        static char git_dir[PATH_MAX+1];
 126                        is_bare_repository_cfg = 1;
 127                        setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 0);
 128                        if (envchanged)
 129                                *envchanged = 1;
 130                } else {
 131                        fprintf(stderr, "Unknown option: %s\n", cmd);
 132                        usage(git_usage_string);
 133                }
 134
 135                (*argv)++;
 136                (*argc)--;
 137                handled++;
 138        }
 139        return handled;
 140}
 141
 142static int handle_alias(int *argcp, const char ***argv)
 143{
 144        int envchanged = 0, ret = 0, saved_errno = errno;
 145        const char *subdir;
 146        int count, option_count;
 147        const char **new_argv;
 148        const char *alias_command;
 149        char *alias_string;
 150        int unused_nongit;
 151
 152        subdir = setup_git_directory_gently(&unused_nongit);
 153
 154        alias_command = (*argv)[0];
 155        alias_string = alias_lookup(alias_command);
 156        if (alias_string) {
 157                if (alias_string[0] == '!') {
 158                        if (*argcp > 1) {
 159                                struct strbuf buf;
 160
 161                                strbuf_init(&buf, PATH_MAX);
 162                                strbuf_addstr(&buf, alias_string);
 163                                sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
 164                                free(alias_string);
 165                                alias_string = buf.buf;
 166                        }
 167                        trace_printf("trace: alias to shell cmd: %s => %s\n",
 168                                     alias_command, alias_string + 1);
 169                        ret = system(alias_string + 1);
 170                        if (ret >= 0 && WIFEXITED(ret) &&
 171                            WEXITSTATUS(ret) != 127)
 172                                exit(WEXITSTATUS(ret));
 173                        die("Failed to run '%s' when expanding alias '%s'",
 174                            alias_string + 1, alias_command);
 175                }
 176                count = split_cmdline(alias_string, &new_argv);
 177                if (count < 0)
 178                        die("Bad alias.%s string", alias_command);
 179                option_count = handle_options(&new_argv, &count, &envchanged);
 180                if (envchanged)
 181                        die("alias '%s' changes environment variables\n"
 182                                 "You can use '!git' in the alias to do this.",
 183                                 alias_command);
 184                memmove(new_argv - option_count, new_argv,
 185                                count * sizeof(char *));
 186                new_argv -= option_count;
 187
 188                if (count < 1)
 189                        die("empty alias for %s", alias_command);
 190
 191                if (!strcmp(alias_command, new_argv[0]))
 192                        die("recursive alias: %s", alias_command);
 193
 194                trace_argv_printf(new_argv,
 195                                  "trace: alias expansion: %s =>",
 196                                  alias_command);
 197
 198                new_argv = xrealloc(new_argv, sizeof(char *) *
 199                                    (count + *argcp));
 200                /* insert after command name */
 201                memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 202
 203                *argv = new_argv;
 204                *argcp += count - 1;
 205
 206                ret = 1;
 207        }
 208
 209        if (subdir && chdir(subdir))
 210                die_errno("Cannot change to '%s'", subdir);
 211
 212        errno = saved_errno;
 213
 214        return ret;
 215}
 216
 217const char git_version_string[] = GIT_VERSION;
 218
 219#define RUN_SETUP       (1<<0)
 220#define USE_PAGER       (1<<1)
 221/*
 222 * require working tree to be present -- anything uses this needs
 223 * RUN_SETUP for reading from the configuration file.
 224 */
 225#define NEED_WORK_TREE  (1<<2)
 226
 227struct cmd_struct {
 228        const char *cmd;
 229        int (*fn)(int, const char **, const char *);
 230        int option;
 231};
 232
 233static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 234{
 235        int status, help;
 236        struct stat st;
 237        const char *prefix;
 238
 239        prefix = NULL;
 240        help = argc == 2 && !strcmp(argv[1], "-h");
 241        if (!help) {
 242                if (p->option & RUN_SETUP)
 243                        prefix = setup_git_directory();
 244
 245                if (use_pager == -1 && p->option & RUN_SETUP)
 246                        use_pager = check_pager_config(p->cmd);
 247                if (use_pager == -1 && p->option & USE_PAGER)
 248                        use_pager = 1;
 249        }
 250        commit_pager_choice();
 251
 252        if (!help && p->option & NEED_WORK_TREE)
 253                setup_work_tree();
 254
 255        trace_argv_printf(argv, "trace: built-in: git");
 256
 257        status = p->fn(argc, argv, prefix);
 258        if (status)
 259                return status;
 260
 261        /* Somebody closed stdout? */
 262        if (fstat(fileno(stdout), &st))
 263                return 0;
 264        /* Ignore write errors for pipes and sockets.. */
 265        if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 266                return 0;
 267
 268        /* Check for ENOSPC and EIO errors.. */
 269        if (fflush(stdout))
 270                die_errno("write failure on standard output");
 271        if (ferror(stdout))
 272                die("unknown write failure on standard output");
 273        if (fclose(stdout))
 274                die_errno("close failed on standard output");
 275        return 0;
 276}
 277
 278static void handle_internal_command(int argc, const char **argv)
 279{
 280        const char *cmd = argv[0];
 281        static struct cmd_struct commands[] = {
 282                { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 283                { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 284                { "annotate", cmd_annotate, RUN_SETUP },
 285                { "apply", cmd_apply },
 286                { "archive", cmd_archive },
 287                { "bisect--helper", cmd_bisect__helper, RUN_SETUP | NEED_WORK_TREE },
 288                { "blame", cmd_blame, RUN_SETUP },
 289                { "branch", cmd_branch, RUN_SETUP },
 290                { "bundle", cmd_bundle },
 291                { "cat-file", cmd_cat_file, RUN_SETUP },
 292                { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 293                { "checkout-index", cmd_checkout_index,
 294                        RUN_SETUP | NEED_WORK_TREE},
 295                { "check-ref-format", cmd_check_ref_format },
 296                { "check-attr", cmd_check_attr, RUN_SETUP },
 297                { "cherry", cmd_cherry, RUN_SETUP },
 298                { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 299                { "clone", cmd_clone },
 300                { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 301                { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 302                { "commit-tree", cmd_commit_tree, RUN_SETUP },
 303                { "config", cmd_config },
 304                { "count-objects", cmd_count_objects, RUN_SETUP },
 305                { "describe", cmd_describe, RUN_SETUP },
 306                { "diff", cmd_diff },
 307                { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 308                { "diff-index", cmd_diff_index, RUN_SETUP },
 309                { "diff-tree", cmd_diff_tree, RUN_SETUP },
 310                { "fast-export", cmd_fast_export, RUN_SETUP },
 311                { "fetch", cmd_fetch, RUN_SETUP },
 312                { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
 313                { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 314                { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 315                { "format-patch", cmd_format_patch, RUN_SETUP },
 316                { "fsck", cmd_fsck, RUN_SETUP },
 317                { "fsck-objects", cmd_fsck, RUN_SETUP },
 318                { "gc", cmd_gc, RUN_SETUP },
 319                { "get-tar-commit-id", cmd_get_tar_commit_id },
 320                { "grep", cmd_grep, RUN_SETUP | USE_PAGER },
 321                { "hash-object", cmd_hash_object },
 322                { "help", cmd_help },
 323                { "index-pack", cmd_index_pack },
 324                { "init", cmd_init_db },
 325                { "init-db", cmd_init_db },
 326                { "log", cmd_log, RUN_SETUP | USE_PAGER },
 327                { "ls-files", cmd_ls_files, RUN_SETUP },
 328                { "ls-tree", cmd_ls_tree, RUN_SETUP },
 329                { "ls-remote", cmd_ls_remote },
 330                { "mailinfo", cmd_mailinfo },
 331                { "mailsplit", cmd_mailsplit },
 332                { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 333                { "merge-base", cmd_merge_base, RUN_SETUP },
 334                { "merge-file", cmd_merge_file },
 335                { "merge-index", cmd_merge_index, RUN_SETUP },
 336                { "merge-ours", cmd_merge_ours, RUN_SETUP },
 337                { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 338                { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 339                { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 340                { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 341                { "merge-tree", cmd_merge_tree, RUN_SETUP },
 342                { "mktag", cmd_mktag, RUN_SETUP },
 343                { "mktree", cmd_mktree, RUN_SETUP },
 344                { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 345                { "name-rev", cmd_name_rev, RUN_SETUP },
 346                { "pack-objects", cmd_pack_objects, RUN_SETUP },
 347                { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
 348                { "patch-id", cmd_patch_id },
 349                { "peek-remote", cmd_ls_remote },
 350                { "pickaxe", cmd_blame, RUN_SETUP },
 351                { "prune", cmd_prune, RUN_SETUP },
 352                { "prune-packed", cmd_prune_packed, RUN_SETUP },
 353                { "push", cmd_push, RUN_SETUP },
 354                { "read-tree", cmd_read_tree, RUN_SETUP },
 355                { "receive-pack", cmd_receive_pack },
 356                { "reflog", cmd_reflog, RUN_SETUP },
 357                { "remote", cmd_remote, RUN_SETUP },
 358                { "replace", cmd_replace, RUN_SETUP },
 359                { "repo-config", cmd_config },
 360                { "rerere", cmd_rerere, RUN_SETUP },
 361                { "reset", cmd_reset, RUN_SETUP },
 362                { "rev-list", cmd_rev_list, RUN_SETUP },
 363                { "rev-parse", cmd_rev_parse },
 364                { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 365                { "rm", cmd_rm, RUN_SETUP },
 366                { "send-pack", cmd_send_pack, RUN_SETUP },
 367                { "shortlog", cmd_shortlog, USE_PAGER },
 368                { "show-branch", cmd_show_branch, RUN_SETUP },
 369                { "show", cmd_show, RUN_SETUP | USE_PAGER },
 370                { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 371                { "stripspace", cmd_stripspace },
 372                { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 373                { "tag", cmd_tag, RUN_SETUP },
 374                { "tar-tree", cmd_tar_tree },
 375                { "unpack-file", cmd_unpack_file, RUN_SETUP },
 376                { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 377                { "update-index", cmd_update_index, RUN_SETUP },
 378                { "update-ref", cmd_update_ref, RUN_SETUP },
 379                { "update-server-info", cmd_update_server_info, RUN_SETUP },
 380                { "upload-archive", cmd_upload_archive },
 381                { "var", cmd_var },
 382                { "verify-tag", cmd_verify_tag, RUN_SETUP },
 383                { "version", cmd_version },
 384                { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
 385                { "write-tree", cmd_write_tree, RUN_SETUP },
 386                { "verify-pack", cmd_verify_pack },
 387                { "show-ref", cmd_show_ref, RUN_SETUP },
 388                { "pack-refs", cmd_pack_refs, RUN_SETUP },
 389        };
 390        int i;
 391        static const char ext[] = STRIP_EXTENSION;
 392
 393        if (sizeof(ext) > 1) {
 394                i = strlen(argv[0]) - strlen(ext);
 395                if (i > 0 && !strcmp(argv[0] + i, ext)) {
 396                        char *argv0 = xstrdup(argv[0]);
 397                        argv[0] = cmd = argv0;
 398                        argv0[i] = '\0';
 399                }
 400        }
 401
 402        /* Turn "git cmd --help" into "git help cmd" */
 403        if (argc > 1 && !strcmp(argv[1], "--help")) {
 404                argv[1] = argv[0];
 405                argv[0] = cmd = "help";
 406        }
 407
 408        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 409                struct cmd_struct *p = commands+i;
 410                if (strcmp(p->cmd, cmd))
 411                        continue;
 412                exit(run_builtin(p, argc, argv));
 413        }
 414}
 415
 416static void execv_dashed_external(const char **argv)
 417{
 418        struct strbuf cmd = STRBUF_INIT;
 419        const char *tmp;
 420        int status;
 421
 422        strbuf_addf(&cmd, "git-%s", argv[0]);
 423
 424        /*
 425         * argv[0] must be the git command, but the argv array
 426         * belongs to the caller, and may be reused in
 427         * subsequent loop iterations. Save argv[0] and
 428         * restore it on error.
 429         */
 430        tmp = argv[0];
 431        argv[0] = cmd.buf;
 432
 433        trace_argv_printf(argv, "trace: exec:");
 434
 435        /*
 436         * if we fail because the command is not found, it is
 437         * OK to return. Otherwise, we just pass along the status code.
 438         */
 439        status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE);
 440        if (status >= 0 || errno != ENOENT)
 441                exit(status);
 442
 443        argv[0] = tmp;
 444
 445        strbuf_release(&cmd);
 446}
 447
 448static int run_argv(int *argcp, const char ***argv)
 449{
 450        int done_alias = 0;
 451
 452        while (1) {
 453                /* See if it's an internal command */
 454                handle_internal_command(*argcp, *argv);
 455
 456                /* .. then try the external ones */
 457                execv_dashed_external(*argv);
 458
 459                /* It could be an alias -- this works around the insanity
 460                 * of overriding "git log" with "git show" by having
 461                 * alias.log = show
 462                 */
 463                if (done_alias || !handle_alias(argcp, argv))
 464                        break;
 465                done_alias = 1;
 466        }
 467
 468        return done_alias;
 469}
 470
 471
 472int main(int argc, const char **argv)
 473{
 474        const char *cmd;
 475
 476        cmd = git_extract_argv0_path(argv[0]);
 477        if (!cmd)
 478                cmd = "git-help";
 479
 480        /*
 481         * "git-xxxx" is the same as "git xxxx", but we obviously:
 482         *
 483         *  - cannot take flags in between the "git" and the "xxxx".
 484         *  - cannot execute it externally (since it would just do
 485         *    the same thing over again)
 486         *
 487         * So we just directly call the internal command handler, and
 488         * die if that one cannot handle it.
 489         */
 490        if (!prefixcmp(cmd, "git-")) {
 491                cmd += 4;
 492                argv[0] = cmd;
 493                handle_internal_command(argc, argv);
 494                die("cannot handle %s internally", cmd);
 495        }
 496
 497        /* Look for flags.. */
 498        argv++;
 499        argc--;
 500        handle_options(&argv, &argc, NULL);
 501        commit_pager_choice();
 502        if (argc > 0) {
 503                if (!prefixcmp(argv[0], "--"))
 504                        argv[0] += 2;
 505        } else {
 506                /* The user didn't specify a command; give them help */
 507                printf("usage: %s\n\n", git_usage_string);
 508                list_common_cmds_help();
 509                printf("\n%s\n", git_more_info_string);
 510                exit(1);
 511        }
 512        cmd = argv[0];
 513
 514        /*
 515         * We use PATH to find git commands, but we prepend some higher
 516         * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 517         * environment, and the $(gitexecdir) from the Makefile at build
 518         * time.
 519         */
 520        setup_path();
 521
 522        while (1) {
 523                static int done_help = 0;
 524                static int was_alias = 0;
 525                was_alias = run_argv(&argc, &argv);
 526                if (errno != ENOENT)
 527                        break;
 528                if (was_alias) {
 529                        fprintf(stderr, "Expansion of alias '%s' failed; "
 530                                "'%s' is not a git-command\n",
 531                                cmd, argv[0]);
 532                        exit(1);
 533                }
 534                if (!done_help) {
 535                        cmd = argv[0] = help_unknown_cmd(cmd);
 536                        done_help = 1;
 537                } else
 538                        break;
 539        }
 540
 541        fprintf(stderr, "Failed to run command '%s': %s\n",
 542                cmd, strerror(errno));
 543
 544        return 1;
 545}