t6300: abstract away SHA-1-specific constants
[git] / git.c
1 #include "builtin.h"
2 #include "config.h"
3 #include "exec-cmd.h"
4 #include "help.h"
5 #include "run-command.h"
6 #include "alias.h"
7
8 #define RUN_SETUP               (1<<0)
9 #define RUN_SETUP_GENTLY        (1<<1)
10 #define USE_PAGER               (1<<2)
11 /*
12  * require working tree to be present -- anything uses this needs
13  * RUN_SETUP for reading from the configuration file.
14  */
15 #define NEED_WORK_TREE          (1<<3)
16 #define SUPPORT_SUPER_PREFIX    (1<<4)
17 #define DELAY_PAGER_CONFIG      (1<<5)
18 #define NO_PARSEOPT             (1<<6) /* parse-options is not used */
19
20 struct cmd_struct {
21         const char *cmd;
22         int (*fn)(int, const char **, const char *);
23         unsigned int option;
24 };
25
26 const char git_usage_string[] =
27         N_("git [--version] [--help] [-C <path>] [-c <name>=<value>]\n"
28            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
29            "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
30            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
31            "           <command> [<args>]");
32
33 const char git_more_info_string[] =
34         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
35            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
36            "to read about a specific subcommand or concept.\n"
37            "See 'git help git' for an overview of the system.");
38
39 static int use_pager = -1;
40
41 static void list_builtins(struct string_list *list, unsigned int exclude_option);
42
43 static void exclude_helpers_from_list(struct string_list *list)
44 {
45         int i = 0;
46
47         while (i < list->nr) {
48                 if (strstr(list->items[i].string, "--"))
49                         unsorted_string_list_delete_item(list, i, 0);
50                 else
51                         i++;
52         }
53 }
54
55 static int match_token(const char *spec, int len, const char *token)
56 {
57         int token_len = strlen(token);
58
59         return len == token_len && !strncmp(spec, token, token_len);
60 }
61
62 static int list_cmds(const char *spec)
63 {
64         struct string_list list = STRING_LIST_INIT_DUP;
65         int i;
66         int nongit;
67
68         /*
69         * Set up the repository so we can pick up any repo-level config (like
70         * completion.commands).
71         */
72         setup_git_directory_gently(&nongit);
73
74         while (*spec) {
75                 const char *sep = strchrnul(spec, ',');
76                 int len = sep - spec;
77
78                 if (match_token(spec, len, "builtins"))
79                         list_builtins(&list, 0);
80                 else if (match_token(spec, len, "main"))
81                         list_all_main_cmds(&list);
82                 else if (match_token(spec, len, "others"))
83                         list_all_other_cmds(&list);
84                 else if (match_token(spec, len, "nohelpers"))
85                         exclude_helpers_from_list(&list);
86                 else if (match_token(spec, len, "alias"))
87                         list_aliases(&list);
88                 else if (match_token(spec, len, "config"))
89                         list_cmds_by_config(&list);
90                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
91                         struct strbuf sb = STRBUF_INIT;
92
93                         strbuf_add(&sb, spec + 5, len - 5);
94                         list_cmds_by_category(&list, sb.buf);
95                         strbuf_release(&sb);
96                 }
97                 else
98                         die(_("unsupported command listing type '%s'"), spec);
99                 spec += len;
100                 if (*spec == ',')
101                         spec++;
102         }
103         for (i = 0; i < list.nr; i++)
104                 puts(list.items[i].string);
105         string_list_clear(&list, 0);
106         return 0;
107 }
108
109 static void commit_pager_choice(void)
110 {
111         switch (use_pager) {
112         case 0:
113                 setenv("GIT_PAGER", "cat", 1);
114                 break;
115         case 1:
116                 setup_pager();
117                 break;
118         default:
119                 break;
120         }
121 }
122
123 void setup_auto_pager(const char *cmd, int def)
124 {
125         if (use_pager != -1 || pager_in_use())
126                 return;
127         use_pager = check_pager_config(cmd);
128         if (use_pager == -1)
129                 use_pager = def;
130         commit_pager_choice();
131 }
132
133 static int handle_options(const char ***argv, int *argc, int *envchanged)
134 {
135         const char **orig_argv = *argv;
136
137         while (*argc > 0) {
138                 const char *cmd = (*argv)[0];
139                 if (cmd[0] != '-')
140                         break;
141
142                 /*
143                  * For legacy reasons, the "version" and "help"
144                  * commands can be written with "--" prepended
145                  * to make them look like flags.
146                  */
147                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
148                         break;
149
150                 /*
151                  * Check remaining flags.
152                  */
153                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
154                         if (*cmd == '=')
155                                 git_set_exec_path(cmd + 1);
156                         else {
157                                 puts(git_exec_path());
158                                 trace2_cmd_name("_query_");
159                                 exit(0);
160                         }
161                 } else if (!strcmp(cmd, "--html-path")) {
162                         puts(system_path(GIT_HTML_PATH));
163                         trace2_cmd_name("_query_");
164                         exit(0);
165                 } else if (!strcmp(cmd, "--man-path")) {
166                         puts(system_path(GIT_MAN_PATH));
167                         trace2_cmd_name("_query_");
168                         exit(0);
169                 } else if (!strcmp(cmd, "--info-path")) {
170                         puts(system_path(GIT_INFO_PATH));
171                         trace2_cmd_name("_query_");
172                         exit(0);
173                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
174                         use_pager = 1;
175                 } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
176                         use_pager = 0;
177                         if (envchanged)
178                                 *envchanged = 1;
179                 } else if (!strcmp(cmd, "--no-replace-objects")) {
180                         read_replace_refs = 0;
181                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
182                         if (envchanged)
183                                 *envchanged = 1;
184                 } else if (!strcmp(cmd, "--git-dir")) {
185                         if (*argc < 2) {
186                                 fprintf(stderr, _("no directory given for --git-dir\n" ));
187                                 usage(git_usage_string);
188                         }
189                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
190                         if (envchanged)
191                                 *envchanged = 1;
192                         (*argv)++;
193                         (*argc)--;
194                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
195                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
196                         if (envchanged)
197                                 *envchanged = 1;
198                 } else if (!strcmp(cmd, "--namespace")) {
199                         if (*argc < 2) {
200                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
201                                 usage(git_usage_string);
202                         }
203                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
204                         if (envchanged)
205                                 *envchanged = 1;
206                         (*argv)++;
207                         (*argc)--;
208                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
209                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
210                         if (envchanged)
211                                 *envchanged = 1;
212                 } else if (!strcmp(cmd, "--work-tree")) {
213                         if (*argc < 2) {
214                                 fprintf(stderr, _("no directory given for --work-tree\n" ));
215                                 usage(git_usage_string);
216                         }
217                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
218                         if (envchanged)
219                                 *envchanged = 1;
220                         (*argv)++;
221                         (*argc)--;
222                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
223                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
224                         if (envchanged)
225                                 *envchanged = 1;
226                 } else if (!strcmp(cmd, "--super-prefix")) {
227                         if (*argc < 2) {
228                                 fprintf(stderr, _("no prefix given for --super-prefix\n" ));
229                                 usage(git_usage_string);
230                         }
231                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
232                         if (envchanged)
233                                 *envchanged = 1;
234                         (*argv)++;
235                         (*argc)--;
236                 } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
237                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
238                         if (envchanged)
239                                 *envchanged = 1;
240                 } else if (!strcmp(cmd, "--bare")) {
241                         char *cwd = xgetcwd();
242                         is_bare_repository_cfg = 1;
243                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
244                         free(cwd);
245                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
246                         if (envchanged)
247                                 *envchanged = 1;
248                 } else if (!strcmp(cmd, "-c")) {
249                         if (*argc < 2) {
250                                 fprintf(stderr, _("-c expects a configuration string\n" ));
251                                 usage(git_usage_string);
252                         }
253                         git_config_push_parameter((*argv)[1]);
254                         (*argv)++;
255                         (*argc)--;
256                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
257                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
258                         if (envchanged)
259                                 *envchanged = 1;
260                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
261                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
262                         if (envchanged)
263                                 *envchanged = 1;
264                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
265                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
266                         if (envchanged)
267                                 *envchanged = 1;
268                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
269                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
270                         if (envchanged)
271                                 *envchanged = 1;
272                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
273                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
274                         if (envchanged)
275                                 *envchanged = 1;
276                 } else if (!strcmp(cmd, "--no-optional-locks")) {
277                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
278                         if (envchanged)
279                                 *envchanged = 1;
280                 } else if (!strcmp(cmd, "--shallow-file")) {
281                         (*argv)++;
282                         (*argc)--;
283                         set_alternate_shallow_file(the_repository, (*argv)[0], 1);
284                         if (envchanged)
285                                 *envchanged = 1;
286                 } else if (!strcmp(cmd, "-C")) {
287                         if (*argc < 2) {
288                                 fprintf(stderr, _("no directory given for -C\n" ));
289                                 usage(git_usage_string);
290                         }
291                         if ((*argv)[1][0]) {
292                                 if (chdir((*argv)[1]))
293                                         die_errno("cannot change to '%s'", (*argv)[1]);
294                                 if (envchanged)
295                                         *envchanged = 1;
296                         }
297                         (*argv)++;
298                         (*argc)--;
299                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
300                         trace2_cmd_name("_query_");
301                         if (!strcmp(cmd, "parseopt")) {
302                                 struct string_list list = STRING_LIST_INIT_DUP;
303                                 int i;
304
305                                 list_builtins(&list, NO_PARSEOPT);
306                                 for (i = 0; i < list.nr; i++)
307                                         printf("%s ", list.items[i].string);
308                                 string_list_clear(&list, 0);
309                                 exit(0);
310                         } else {
311                                 exit(list_cmds(cmd));
312                         }
313                 } else {
314                         fprintf(stderr, _("unknown option: %s\n"), cmd);
315                         usage(git_usage_string);
316                 }
317
318                 (*argv)++;
319                 (*argc)--;
320         }
321         return (*argv) - orig_argv;
322 }
323
324 static int handle_alias(int *argcp, const char ***argv)
325 {
326         int envchanged = 0, ret = 0, saved_errno = errno;
327         int count, option_count;
328         const char **new_argv;
329         const char *alias_command;
330         char *alias_string;
331
332         alias_command = (*argv)[0];
333         alias_string = alias_lookup(alias_command);
334         if (alias_string) {
335                 if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
336                         fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
337                                    alias_command, alias_string);
338                 if (alias_string[0] == '!') {
339                         struct child_process child = CHILD_PROCESS_INIT;
340                         int nongit_ok;
341
342                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
343                         setup_git_directory_gently(&nongit_ok);
344
345                         commit_pager_choice();
346
347                         child.use_shell = 1;
348                         child.trace2_child_class = "shell_alias";
349                         argv_array_push(&child.args, alias_string + 1);
350                         argv_array_pushv(&child.args, (*argv) + 1);
351
352                         trace2_cmd_alias(alias_command, child.args.argv);
353                         trace2_cmd_list_config();
354                         trace2_cmd_name("_run_shell_alias_");
355
356                         ret = run_command(&child);
357                         if (ret >= 0)   /* normal exit */
358                                 exit(ret);
359
360                         die_errno(_("while expanding alias '%s': '%s'"),
361                                   alias_command, alias_string + 1);
362                 }
363                 count = split_cmdline(alias_string, &new_argv);
364                 if (count < 0)
365                         die(_("bad alias.%s string: %s"), alias_command,
366                             _(split_cmdline_strerror(count)));
367                 option_count = handle_options(&new_argv, &count, &envchanged);
368                 if (envchanged)
369                         die(_("alias '%s' changes environment variables.\n"
370                               "You can use '!git' in the alias to do this"),
371                             alias_command);
372                 MOVE_ARRAY(new_argv - option_count, new_argv, count);
373                 new_argv -= option_count;
374
375                 if (count < 1)
376                         die(_("empty alias for %s"), alias_command);
377
378                 if (!strcmp(alias_command, new_argv[0]))
379                         die(_("recursive alias: %s"), alias_command);
380
381                 trace_argv_printf(new_argv,
382                                   "trace: alias expansion: %s =>",
383                                   alias_command);
384
385                 REALLOC_ARRAY(new_argv, count + *argcp);
386                 /* insert after command name */
387                 COPY_ARRAY(new_argv + count, *argv + 1, *argcp);
388
389                 trace2_cmd_alias(alias_command, new_argv);
390                 trace2_cmd_list_config();
391
392                 *argv = new_argv;
393                 *argcp += count - 1;
394
395                 ret = 1;
396         }
397
398         errno = saved_errno;
399
400         return ret;
401 }
402
403 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
404 {
405         int status, help;
406         struct stat st;
407         const char *prefix;
408
409         prefix = NULL;
410         help = argc == 2 && !strcmp(argv[1], "-h");
411         if (!help) {
412                 if (p->option & RUN_SETUP)
413                         prefix = setup_git_directory();
414                 else if (p->option & RUN_SETUP_GENTLY) {
415                         int nongit_ok;
416                         prefix = setup_git_directory_gently(&nongit_ok);
417                 }
418
419                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
420                     !(p->option & DELAY_PAGER_CONFIG))
421                         use_pager = check_pager_config(p->cmd);
422                 if (use_pager == -1 && p->option & USE_PAGER)
423                         use_pager = 1;
424
425                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
426                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
427                         trace_repo_setup(prefix);
428         }
429         commit_pager_choice();
430
431         if (!help && get_super_prefix()) {
432                 if (!(p->option & SUPPORT_SUPER_PREFIX))
433                         die(_("%s doesn't support --super-prefix"), p->cmd);
434         }
435
436         if (!help && p->option & NEED_WORK_TREE)
437                 setup_work_tree();
438
439         trace_argv_printf(argv, "trace: built-in: git");
440         trace2_cmd_name(p->cmd);
441         trace2_cmd_list_config();
442
443         validate_cache_entries(the_repository->index);
444         status = p->fn(argc, argv, prefix);
445         validate_cache_entries(the_repository->index);
446
447         if (status)
448                 return status;
449
450         /* Somebody closed stdout? */
451         if (fstat(fileno(stdout), &st))
452                 return 0;
453         /* Ignore write errors for pipes and sockets.. */
454         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
455                 return 0;
456
457         /* Check for ENOSPC and EIO errors.. */
458         if (fflush(stdout))
459                 die_errno(_("write failure on standard output"));
460         if (ferror(stdout))
461                 die(_("unknown write failure on standard output"));
462         if (fclose(stdout))
463                 die_errno(_("close failed on standard output"));
464         return 0;
465 }
466
467 static struct cmd_struct commands[] = {
468         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
469         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
470         { "annotate", cmd_annotate, RUN_SETUP | NO_PARSEOPT },
471         { "apply", cmd_apply, RUN_SETUP_GENTLY },
472         { "archive", cmd_archive, RUN_SETUP_GENTLY },
473         { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
474         { "blame", cmd_blame, RUN_SETUP },
475         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
476         { "bundle", cmd_bundle, RUN_SETUP_GENTLY | NO_PARSEOPT },
477         { "cat-file", cmd_cat_file, RUN_SETUP },
478         { "check-attr", cmd_check_attr, RUN_SETUP },
479         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
480         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
481         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
482         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
483         { "checkout-index", cmd_checkout_index,
484                 RUN_SETUP | NEED_WORK_TREE},
485         { "cherry", cmd_cherry, RUN_SETUP },
486         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
487         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
488         { "clone", cmd_clone },
489         { "column", cmd_column, RUN_SETUP_GENTLY },
490         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
491         { "commit-graph", cmd_commit_graph, RUN_SETUP },
492         { "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
493         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
494         { "count-objects", cmd_count_objects, RUN_SETUP },
495         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
496         { "describe", cmd_describe, RUN_SETUP },
497         { "diff", cmd_diff, NO_PARSEOPT },
498         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
499         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
500         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
501         { "difftool", cmd_difftool, RUN_SETUP_GENTLY },
502         { "env--helper", cmd_env__helper },
503         { "fast-export", cmd_fast_export, RUN_SETUP },
504         { "fetch", cmd_fetch, RUN_SETUP },
505         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
506         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
507         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
508         { "format-patch", cmd_format_patch, RUN_SETUP },
509         { "fsck", cmd_fsck, RUN_SETUP },
510         { "fsck-objects", cmd_fsck, RUN_SETUP },
511         { "gc", cmd_gc, RUN_SETUP },
512         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
513         { "grep", cmd_grep, RUN_SETUP_GENTLY },
514         { "hash-object", cmd_hash_object },
515         { "help", cmd_help },
516         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
517         { "init", cmd_init_db },
518         { "init-db", cmd_init_db },
519         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
520         { "log", cmd_log, RUN_SETUP },
521         { "ls-files", cmd_ls_files, RUN_SETUP },
522         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
523         { "ls-tree", cmd_ls_tree, RUN_SETUP },
524         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY | NO_PARSEOPT },
525         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
526         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
527         { "merge-base", cmd_merge_base, RUN_SETUP },
528         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
529         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
530         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
531         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
532         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
533         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
534         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
535         { "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
536         { "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
537         { "mktree", cmd_mktree, RUN_SETUP },
538         { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP_GENTLY },
539         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
540         { "name-rev", cmd_name_rev, RUN_SETUP },
541         { "notes", cmd_notes, RUN_SETUP },
542         { "pack-objects", cmd_pack_objects, RUN_SETUP },
543         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
544         { "pack-refs", cmd_pack_refs, RUN_SETUP },
545         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
546         { "pickaxe", cmd_blame, RUN_SETUP },
547         { "prune", cmd_prune, RUN_SETUP },
548         { "prune-packed", cmd_prune_packed, RUN_SETUP },
549         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
550         { "push", cmd_push, RUN_SETUP },
551         { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
552         { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
553         { "rebase", cmd_rebase, RUN_SETUP | NEED_WORK_TREE },
554         { "rebase--interactive", cmd_rebase__interactive, RUN_SETUP | NEED_WORK_TREE },
555         { "receive-pack", cmd_receive_pack },
556         { "reflog", cmd_reflog, RUN_SETUP },
557         { "remote", cmd_remote, RUN_SETUP },
558         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
559         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
560         { "repack", cmd_repack, RUN_SETUP },
561         { "replace", cmd_replace, RUN_SETUP },
562         { "rerere", cmd_rerere, RUN_SETUP },
563         { "reset", cmd_reset, RUN_SETUP },
564         { "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
565         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
566         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
567         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
568         { "rm", cmd_rm, RUN_SETUP },
569         { "send-pack", cmd_send_pack, RUN_SETUP },
570         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
571         { "show", cmd_show, RUN_SETUP },
572         { "show-branch", cmd_show_branch, RUN_SETUP },
573         { "show-index", cmd_show_index },
574         { "show-ref", cmd_show_ref, RUN_SETUP },
575         { "sparse-checkout", cmd_sparse_checkout, RUN_SETUP | NEED_WORK_TREE },
576         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
577         /*
578          * NEEDSWORK: Until the builtin stash is thoroughly robust and no
579          * longer needs redirection to the stash shell script this is kept as
580          * is, then should be changed to RUN_SETUP | NEED_WORK_TREE
581          */
582         { "stash", cmd_stash },
583         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
584         { "stripspace", cmd_stripspace },
585         { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
586         { "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
587         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
588         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
589         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
590         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
591         { "update-index", cmd_update_index, RUN_SETUP },
592         { "update-ref", cmd_update_ref, RUN_SETUP },
593         { "update-server-info", cmd_update_server_info, RUN_SETUP },
594         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
595         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
596         { "upload-pack", cmd_upload_pack },
597         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
598         { "verify-commit", cmd_verify_commit, RUN_SETUP },
599         { "verify-pack", cmd_verify_pack },
600         { "verify-tag", cmd_verify_tag, RUN_SETUP },
601         { "version", cmd_version },
602         { "whatchanged", cmd_whatchanged, RUN_SETUP },
603         { "worktree", cmd_worktree, RUN_SETUP | NO_PARSEOPT },
604         { "write-tree", cmd_write_tree, RUN_SETUP },
605 };
606
607 static struct cmd_struct *get_builtin(const char *s)
608 {
609         int i;
610         for (i = 0; i < ARRAY_SIZE(commands); i++) {
611                 struct cmd_struct *p = commands + i;
612                 if (!strcmp(s, p->cmd))
613                         return p;
614         }
615         return NULL;
616 }
617
618 int is_builtin(const char *s)
619 {
620         return !!get_builtin(s);
621 }
622
623 static void list_builtins(struct string_list *out, unsigned int exclude_option)
624 {
625         int i;
626         for (i = 0; i < ARRAY_SIZE(commands); i++) {
627                 if (exclude_option &&
628                     (commands[i].option & exclude_option))
629                         continue;
630                 string_list_append(out, commands[i].cmd);
631         }
632 }
633
634 #ifdef STRIP_EXTENSION
635 static void strip_extension(const char **argv)
636 {
637         size_t len;
638
639         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
640                 argv[0] = xmemdupz(argv[0], len);
641 }
642 #else
643 #define strip_extension(cmd)
644 #endif
645
646 static void handle_builtin(int argc, const char **argv)
647 {
648         struct argv_array args = ARGV_ARRAY_INIT;
649         const char *cmd;
650         struct cmd_struct *builtin;
651
652         strip_extension(argv);
653         cmd = argv[0];
654
655         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
656         if (argc > 1 && !strcmp(argv[1], "--help")) {
657                 int i;
658
659                 argv[1] = argv[0];
660                 argv[0] = cmd = "help";
661
662                 for (i = 0; i < argc; i++) {
663                         argv_array_push(&args, argv[i]);
664                         if (!i)
665                                 argv_array_push(&args, "--exclude-guides");
666                 }
667
668                 argc++;
669                 argv = args.argv;
670         }
671
672         builtin = get_builtin(cmd);
673         if (builtin)
674                 exit(run_builtin(builtin, argc, argv));
675         argv_array_clear(&args);
676 }
677
678 static void execv_dashed_external(const char **argv)
679 {
680         struct child_process cmd = CHILD_PROCESS_INIT;
681         int status;
682
683         if (get_super_prefix())
684                 die(_("%s doesn't support --super-prefix"), argv[0]);
685
686         if (use_pager == -1 && !is_builtin(argv[0]))
687                 use_pager = check_pager_config(argv[0]);
688         commit_pager_choice();
689
690         argv_array_pushf(&cmd.args, "git-%s", argv[0]);
691         argv_array_pushv(&cmd.args, argv + 1);
692         cmd.clean_on_exit = 1;
693         cmd.wait_after_clean = 1;
694         cmd.silent_exec_failure = 1;
695         cmd.trace2_child_class = "dashed";
696
697         trace2_cmd_name("_run_dashed_");
698
699         /*
700          * The code in run_command() logs trace2 child_start/child_exit
701          * events, so we do not need to report exec/exec_result events here.
702          */
703         trace_argv_printf(cmd.args.argv, "trace: exec:");
704
705         /*
706          * If we fail because the command is not found, it is
707          * OK to return. Otherwise, we just pass along the status code,
708          * or our usual generic code if we were not even able to exec
709          * the program.
710          */
711         status = run_command(&cmd);
712
713         /*
714          * If the child process ran and we are now going to exit, emit a
715          * generic string as our trace2 command verb to indicate that we
716          * launched a dashed command.
717          */
718         if (status >= 0)
719                 exit(status);
720         else if (errno != ENOENT)
721                 exit(128);
722 }
723
724 static int run_argv(int *argcp, const char ***argv)
725 {
726         int done_alias = 0;
727         struct string_list cmd_list = STRING_LIST_INIT_NODUP;
728         struct string_list_item *seen;
729
730         while (1) {
731                 /*
732                  * If we tried alias and futzed with our environment,
733                  * it no longer is safe to invoke builtins directly in
734                  * general.  We have to spawn them as dashed externals.
735                  *
736                  * NEEDSWORK: if we can figure out cases
737                  * where it is safe to do, we can avoid spawning a new
738                  * process.
739                  */
740                 if (!done_alias)
741                         handle_builtin(*argcp, *argv);
742                 else if (get_builtin(**argv)) {
743                         struct argv_array args = ARGV_ARRAY_INIT;
744                         int i;
745
746                         /*
747                          * The current process is committed to launching a
748                          * child process to run the command named in (**argv)
749                          * and exiting.  Log a generic string as the trace2
750                          * command verb to indicate this.  Note that the child
751                          * process will log the actual verb when it runs.
752                          */
753                         trace2_cmd_name("_run_git_alias_");
754
755                         if (get_super_prefix())
756                                 die("%s doesn't support --super-prefix", **argv);
757
758                         commit_pager_choice();
759
760                         argv_array_push(&args, "git");
761                         for (i = 0; i < *argcp; i++)
762                                 argv_array_push(&args, (*argv)[i]);
763
764                         trace_argv_printf(args.argv, "trace: exec:");
765
766                         /*
767                          * if we fail because the command is not found, it is
768                          * OK to return. Otherwise, we just pass along the status code.
769                          */
770                         i = run_command_v_opt_tr2(args.argv, RUN_SILENT_EXEC_FAILURE |
771                                                   RUN_CLEAN_ON_EXIT, "git_alias");
772                         if (i >= 0 || errno != ENOENT)
773                                 exit(i);
774                         die("could not execute builtin %s", **argv);
775                 }
776
777                 /* .. then try the external ones */
778                 execv_dashed_external(*argv);
779
780                 seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
781                 if (seen) {
782                         int i;
783                         struct strbuf sb = STRBUF_INIT;
784                         for (i = 0; i < cmd_list.nr; i++) {
785                                 struct string_list_item *item = &cmd_list.items[i];
786
787                                 strbuf_addf(&sb, "\n  %s", item->string);
788                                 if (item == seen)
789                                         strbuf_addstr(&sb, " <==");
790                                 else if (i == cmd_list.nr - 1)
791                                         strbuf_addstr(&sb, " ==>");
792                         }
793                         die(_("alias loop detected: expansion of '%s' does"
794                               " not terminate:%s"), cmd_list.items[0].string, sb.buf);
795                 }
796
797                 string_list_append(&cmd_list, *argv[0]);
798
799                 /*
800                  * It could be an alias -- this works around the insanity
801                  * of overriding "git log" with "git show" by having
802                  * alias.log = show
803                  */
804                 if (!handle_alias(argcp, argv))
805                         break;
806                 done_alias = 1;
807         }
808
809         string_list_clear(&cmd_list, 0);
810
811         return done_alias;
812 }
813
814 int cmd_main(int argc, const char **argv)
815 {
816         const char *cmd;
817         int done_help = 0;
818
819         cmd = argv[0];
820         if (!cmd)
821                 cmd = "git-help";
822         else {
823                 const char *slash = find_last_dir_sep(cmd);
824                 if (slash)
825                         cmd = slash + 1;
826         }
827
828         trace_command_performance(argv);
829
830         /*
831          * "git-xxxx" is the same as "git xxxx", but we obviously:
832          *
833          *  - cannot take flags in between the "git" and the "xxxx".
834          *  - cannot execute it externally (since it would just do
835          *    the same thing over again)
836          *
837          * So we just directly call the builtin handler, and die if
838          * that one cannot handle it.
839          */
840         if (skip_prefix(cmd, "git-", &cmd)) {
841                 argv[0] = cmd;
842                 handle_builtin(argc, argv);
843                 die(_("cannot handle %s as a builtin"), cmd);
844         }
845
846         /* Look for flags.. */
847         argv++;
848         argc--;
849         handle_options(&argv, &argc, NULL);
850         if (argc > 0) {
851                 /* translate --help and --version into commands */
852                 skip_prefix(argv[0], "--", &argv[0]);
853         } else {
854                 /* The user didn't specify a command; give them help */
855                 commit_pager_choice();
856                 printf(_("usage: %s\n\n"), git_usage_string);
857                 list_common_cmds_help();
858                 printf("\n%s\n", _(git_more_info_string));
859                 exit(1);
860         }
861         cmd = argv[0];
862
863         /*
864          * We use PATH to find git commands, but we prepend some higher
865          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
866          * environment, and the $(gitexecdir) from the Makefile at build
867          * time.
868          */
869         setup_path();
870
871         while (1) {
872                 int was_alias = run_argv(&argc, &argv);
873                 if (errno != ENOENT)
874                         break;
875                 if (was_alias) {
876                         fprintf(stderr, _("expansion of alias '%s' failed; "
877                                           "'%s' is not a git command\n"),
878                                 cmd, argv[0]);
879                         exit(1);
880                 }
881                 if (!done_help) {
882                         cmd = argv[0] = help_unknown_cmd(cmd);
883                         done_help = 1;
884                 } else
885                         break;
886         }
887
888         fprintf(stderr, _("failed to run command '%s': %s\n"),
889                 cmd, strerror(errno));
890
891         return 1;
892 }