Merge branch 'jn/v0-with-extensions-fix' into master
[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 #include "shallow.h"
8
9 #define RUN_SETUP               (1<<0)
10 #define RUN_SETUP_GENTLY        (1<<1)
11 #define USE_PAGER               (1<<2)
12 /*
13  * require working tree to be present -- anything uses this needs
14  * RUN_SETUP for reading from the configuration file.
15  */
16 #define NEED_WORK_TREE          (1<<3)
17 #define SUPPORT_SUPER_PREFIX    (1<<4)
18 #define DELAY_PAGER_CONFIG      (1<<5)
19 #define NO_PARSEOPT             (1<<6) /* parse-options is not used */
20
21 struct cmd_struct {
22         const char *cmd;
23         int (*fn)(int, const char **, const char *);
24         unsigned int option;
25 };
26
27 const char git_usage_string[] =
28         N_("git [--version] [--help] [-C <path>] [-c <name>=<value>]\n"
29            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
30            "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
31            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
32            "           <command> [<args>]");
33
34 const char git_more_info_string[] =
35         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
36            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
37            "to read about a specific subcommand or concept.\n"
38            "See 'git help git' for an overview of the system.");
39
40 static int use_pager = -1;
41
42 static void list_builtins(struct string_list *list, unsigned int exclude_option);
43
44 static void exclude_helpers_from_list(struct string_list *list)
45 {
46         int i = 0;
47
48         while (i < list->nr) {
49                 if (strstr(list->items[i].string, "--"))
50                         unsorted_string_list_delete_item(list, i, 0);
51                 else
52                         i++;
53         }
54 }
55
56 static int match_token(const char *spec, int len, const char *token)
57 {
58         int token_len = strlen(token);
59
60         return len == token_len && !strncmp(spec, token, token_len);
61 }
62
63 static int list_cmds(const char *spec)
64 {
65         struct string_list list = STRING_LIST_INIT_DUP;
66         int i;
67         int nongit;
68
69         /*
70         * Set up the repository so we can pick up any repo-level config (like
71         * completion.commands).
72         */
73         setup_git_directory_gently(&nongit);
74
75         while (*spec) {
76                 const char *sep = strchrnul(spec, ',');
77                 int len = sep - spec;
78
79                 if (match_token(spec, len, "builtins"))
80                         list_builtins(&list, 0);
81                 else if (match_token(spec, len, "main"))
82                         list_all_main_cmds(&list);
83                 else if (match_token(spec, len, "others"))
84                         list_all_other_cmds(&list);
85                 else if (match_token(spec, len, "nohelpers"))
86                         exclude_helpers_from_list(&list);
87                 else if (match_token(spec, len, "alias"))
88                         list_aliases(&list);
89                 else if (match_token(spec, len, "config"))
90                         list_cmds_by_config(&list);
91                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
92                         struct strbuf sb = STRBUF_INIT;
93
94                         strbuf_add(&sb, spec + 5, len - 5);
95                         list_cmds_by_category(&list, sb.buf);
96                         strbuf_release(&sb);
97                 }
98                 else
99                         die(_("unsupported command listing type '%s'"), spec);
100                 spec += len;
101                 if (*spec == ',')
102                         spec++;
103         }
104         for (i = 0; i < list.nr; i++)
105                 puts(list.items[i].string);
106         string_list_clear(&list, 0);
107         return 0;
108 }
109
110 static void commit_pager_choice(void)
111 {
112         switch (use_pager) {
113         case 0:
114                 setenv("GIT_PAGER", "cat", 1);
115                 break;
116         case 1:
117                 setup_pager();
118                 break;
119         default:
120                 break;
121         }
122 }
123
124 void setup_auto_pager(const char *cmd, int def)
125 {
126         if (use_pager != -1 || pager_in_use())
127                 return;
128         use_pager = check_pager_config(cmd);
129         if (use_pager == -1)
130                 use_pager = def;
131         commit_pager_choice();
132 }
133
134 static int handle_options(const char ***argv, int *argc, int *envchanged)
135 {
136         const char **orig_argv = *argv;
137
138         while (*argc > 0) {
139                 const char *cmd = (*argv)[0];
140                 if (cmd[0] != '-')
141                         break;
142
143                 /*
144                  * For legacy reasons, the "version" and "help"
145                  * commands can be written with "--" prepended
146                  * to make them look like flags.
147                  */
148                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
149                         break;
150
151                 /*
152                  * Check remaining flags.
153                  */
154                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
155                         if (*cmd == '=')
156                                 git_set_exec_path(cmd + 1);
157                         else {
158                                 puts(git_exec_path());
159                                 trace2_cmd_name("_query_");
160                                 exit(0);
161                         }
162                 } else if (!strcmp(cmd, "--html-path")) {
163                         puts(system_path(GIT_HTML_PATH));
164                         trace2_cmd_name("_query_");
165                         exit(0);
166                 } else if (!strcmp(cmd, "--man-path")) {
167                         puts(system_path(GIT_MAN_PATH));
168                         trace2_cmd_name("_query_");
169                         exit(0);
170                 } else if (!strcmp(cmd, "--info-path")) {
171                         puts(system_path(GIT_INFO_PATH));
172                         trace2_cmd_name("_query_");
173                         exit(0);
174                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
175                         use_pager = 1;
176                 } else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
177                         use_pager = 0;
178                         if (envchanged)
179                                 *envchanged = 1;
180                 } else if (!strcmp(cmd, "--no-replace-objects")) {
181                         read_replace_refs = 0;
182                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
183                         if (envchanged)
184                                 *envchanged = 1;
185                 } else if (!strcmp(cmd, "--git-dir")) {
186                         if (*argc < 2) {
187                                 fprintf(stderr, _("no directory given for --git-dir\n" ));
188                                 usage(git_usage_string);
189                         }
190                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
191                         if (envchanged)
192                                 *envchanged = 1;
193                         (*argv)++;
194                         (*argc)--;
195                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
196                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
197                         if (envchanged)
198                                 *envchanged = 1;
199                 } else if (!strcmp(cmd, "--namespace")) {
200                         if (*argc < 2) {
201                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
202                                 usage(git_usage_string);
203                         }
204                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
205                         if (envchanged)
206                                 *envchanged = 1;
207                         (*argv)++;
208                         (*argc)--;
209                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
210                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
211                         if (envchanged)
212                                 *envchanged = 1;
213                 } else if (!strcmp(cmd, "--work-tree")) {
214                         if (*argc < 2) {
215                                 fprintf(stderr, _("no directory given for --work-tree\n" ));
216                                 usage(git_usage_string);
217                         }
218                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
219                         if (envchanged)
220                                 *envchanged = 1;
221                         (*argv)++;
222                         (*argc)--;
223                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
224                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
225                         if (envchanged)
226                                 *envchanged = 1;
227                 } else if (!strcmp(cmd, "--super-prefix")) {
228                         if (*argc < 2) {
229                                 fprintf(stderr, _("no prefix given for --super-prefix\n" ));
230                                 usage(git_usage_string);
231                         }
232                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
233                         if (envchanged)
234                                 *envchanged = 1;
235                         (*argv)++;
236                         (*argc)--;
237                 } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
238                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
239                         if (envchanged)
240                                 *envchanged = 1;
241                 } else if (!strcmp(cmd, "--bare")) {
242                         char *cwd = xgetcwd();
243                         is_bare_repository_cfg = 1;
244                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
245                         free(cwd);
246                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
247                         if (envchanged)
248                                 *envchanged = 1;
249                 } else if (!strcmp(cmd, "-c")) {
250                         if (*argc < 2) {
251                                 fprintf(stderr, _("-c expects a configuration string\n" ));
252                                 usage(git_usage_string);
253                         }
254                         git_config_push_parameter((*argv)[1]);
255                         (*argv)++;
256                         (*argc)--;
257                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
258                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
259                         if (envchanged)
260                                 *envchanged = 1;
261                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
262                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
263                         if (envchanged)
264                                 *envchanged = 1;
265                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
266                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
267                         if (envchanged)
268                                 *envchanged = 1;
269                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
270                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
271                         if (envchanged)
272                                 *envchanged = 1;
273                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
274                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
275                         if (envchanged)
276                                 *envchanged = 1;
277                 } else if (!strcmp(cmd, "--no-optional-locks")) {
278                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
279                         if (envchanged)
280                                 *envchanged = 1;
281                 } else if (!strcmp(cmd, "--shallow-file")) {
282                         (*argv)++;
283                         (*argc)--;
284                         set_alternate_shallow_file(the_repository, (*argv)[0], 1);
285                         if (envchanged)
286                                 *envchanged = 1;
287                 } else if (!strcmp(cmd, "-C")) {
288                         if (*argc < 2) {
289                                 fprintf(stderr, _("no directory given for -C\n" ));
290                                 usage(git_usage_string);
291                         }
292                         if ((*argv)[1][0]) {
293                                 if (chdir((*argv)[1]))
294                                         die_errno("cannot change to '%s'", (*argv)[1]);
295                                 if (envchanged)
296                                         *envchanged = 1;
297                         }
298                         (*argv)++;
299                         (*argc)--;
300                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
301                         trace2_cmd_name("_query_");
302                         if (!strcmp(cmd, "parseopt")) {
303                                 struct string_list list = STRING_LIST_INIT_DUP;
304                                 int i;
305
306                                 list_builtins(&list, NO_PARSEOPT);
307                                 for (i = 0; i < list.nr; i++)
308                                         printf("%s ", list.items[i].string);
309                                 string_list_clear(&list, 0);
310                                 exit(0);
311                         } else {
312                                 exit(list_cmds(cmd));
313                         }
314                 } else {
315                         fprintf(stderr, _("unknown option: %s\n"), cmd);
316                         usage(git_usage_string);
317                 }
318
319                 (*argv)++;
320                 (*argc)--;
321         }
322         return (*argv) - orig_argv;
323 }
324
325 static int handle_alias(int *argcp, const char ***argv)
326 {
327         int envchanged = 0, ret = 0, saved_errno = errno;
328         int count, option_count;
329         const char **new_argv;
330         const char *alias_command;
331         char *alias_string;
332
333         alias_command = (*argv)[0];
334         alias_string = alias_lookup(alias_command);
335         if (alias_string) {
336                 if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
337                         fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
338                                    alias_command, alias_string);
339                 if (alias_string[0] == '!') {
340                         struct child_process child = CHILD_PROCESS_INIT;
341                         int nongit_ok;
342
343                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
344                         setup_git_directory_gently(&nongit_ok);
345
346                         commit_pager_choice();
347
348                         child.use_shell = 1;
349                         child.clean_on_exit = 1;
350                         child.wait_after_clean = 1;
351                         child.trace2_child_class = "shell_alias";
352                         argv_array_push(&child.args, alias_string + 1);
353                         argv_array_pushv(&child.args, (*argv) + 1);
354
355                         trace2_cmd_alias(alias_command, child.args.argv);
356                         trace2_cmd_list_config();
357                         trace2_cmd_list_env_vars();
358                         trace2_cmd_name("_run_shell_alias_");
359
360                         ret = run_command(&child);
361                         if (ret >= 0)   /* normal exit */
362                                 exit(ret);
363
364                         die_errno(_("while expanding alias '%s': '%s'"),
365                                   alias_command, alias_string + 1);
366                 }
367                 count = split_cmdline(alias_string, &new_argv);
368                 if (count < 0)
369                         die(_("bad alias.%s string: %s"), alias_command,
370                             _(split_cmdline_strerror(count)));
371                 option_count = handle_options(&new_argv, &count, &envchanged);
372                 if (envchanged)
373                         die(_("alias '%s' changes environment variables.\n"
374                               "You can use '!git' in the alias to do this"),
375                             alias_command);
376                 MOVE_ARRAY(new_argv - option_count, new_argv, count);
377                 new_argv -= option_count;
378
379                 if (count < 1)
380                         die(_("empty alias for %s"), alias_command);
381
382                 if (!strcmp(alias_command, new_argv[0]))
383                         die(_("recursive alias: %s"), alias_command);
384
385                 trace_argv_printf(new_argv,
386                                   "trace: alias expansion: %s =>",
387                                   alias_command);
388
389                 REALLOC_ARRAY(new_argv, count + *argcp);
390                 /* insert after command name */
391                 COPY_ARRAY(new_argv + count, *argv + 1, *argcp);
392
393                 trace2_cmd_alias(alias_command, new_argv);
394                 trace2_cmd_list_config();
395                 trace2_cmd_list_env_vars();
396
397                 *argv = new_argv;
398                 *argcp += count - 1;
399
400                 ret = 1;
401         }
402
403         errno = saved_errno;
404
405         return ret;
406 }
407
408 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
409 {
410         int status, help;
411         struct stat st;
412         const char *prefix;
413
414         prefix = NULL;
415         help = argc == 2 && !strcmp(argv[1], "-h");
416         if (!help) {
417                 if (p->option & RUN_SETUP)
418                         prefix = setup_git_directory();
419                 else if (p->option & RUN_SETUP_GENTLY) {
420                         int nongit_ok;
421                         prefix = setup_git_directory_gently(&nongit_ok);
422                 }
423
424                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
425                     !(p->option & DELAY_PAGER_CONFIG))
426                         use_pager = check_pager_config(p->cmd);
427                 if (use_pager == -1 && p->option & USE_PAGER)
428                         use_pager = 1;
429
430                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
431                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
432                         trace_repo_setup(prefix);
433         }
434         commit_pager_choice();
435
436         if (!help && get_super_prefix()) {
437                 if (!(p->option & SUPPORT_SUPER_PREFIX))
438                         die(_("%s doesn't support --super-prefix"), p->cmd);
439         }
440
441         if (!help && p->option & NEED_WORK_TREE)
442                 setup_work_tree();
443
444         trace_argv_printf(argv, "trace: built-in: git");
445         trace2_cmd_name(p->cmd);
446         trace2_cmd_list_config();
447         trace2_cmd_list_env_vars();
448
449         validate_cache_entries(the_repository->index);
450         status = p->fn(argc, argv, prefix);
451         validate_cache_entries(the_repository->index);
452
453         if (status)
454                 return status;
455
456         /* Somebody closed stdout? */
457         if (fstat(fileno(stdout), &st))
458                 return 0;
459         /* Ignore write errors for pipes and sockets.. */
460         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
461                 return 0;
462
463         /* Check for ENOSPC and EIO errors.. */
464         if (fflush(stdout))
465                 die_errno(_("write failure on standard output"));
466         if (ferror(stdout))
467                 die(_("unknown write failure on standard output"));
468         if (fclose(stdout))
469                 die_errno(_("close failed on standard output"));
470         return 0;
471 }
472
473 static struct cmd_struct commands[] = {
474         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
475         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
476         { "annotate", cmd_annotate, RUN_SETUP | NO_PARSEOPT },
477         { "apply", cmd_apply, RUN_SETUP_GENTLY },
478         { "archive", cmd_archive, RUN_SETUP_GENTLY },
479         { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
480         { "blame", cmd_blame, RUN_SETUP },
481         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
482         { "bundle", cmd_bundle, RUN_SETUP_GENTLY | NO_PARSEOPT },
483         { "cat-file", cmd_cat_file, RUN_SETUP },
484         { "check-attr", cmd_check_attr, RUN_SETUP },
485         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
486         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
487         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
488         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
489         { "checkout-index", cmd_checkout_index,
490                 RUN_SETUP | NEED_WORK_TREE},
491         { "cherry", cmd_cherry, RUN_SETUP },
492         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
493         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
494         { "clone", cmd_clone },
495         { "column", cmd_column, RUN_SETUP_GENTLY },
496         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
497         { "commit-graph", cmd_commit_graph, RUN_SETUP },
498         { "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
499         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
500         { "count-objects", cmd_count_objects, RUN_SETUP },
501         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
502         { "describe", cmd_describe, RUN_SETUP },
503         { "diff", cmd_diff, NO_PARSEOPT },
504         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
505         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
506         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
507         { "difftool", cmd_difftool, RUN_SETUP_GENTLY },
508         { "env--helper", cmd_env__helper },
509         { "fast-export", cmd_fast_export, RUN_SETUP },
510         { "fetch", cmd_fetch, RUN_SETUP },
511         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
512         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
513         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
514         { "format-patch", cmd_format_patch, RUN_SETUP },
515         { "fsck", cmd_fsck, RUN_SETUP },
516         { "fsck-objects", cmd_fsck, RUN_SETUP },
517         { "gc", cmd_gc, RUN_SETUP },
518         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
519         { "grep", cmd_grep, RUN_SETUP_GENTLY },
520         { "hash-object", cmd_hash_object },
521         { "help", cmd_help },
522         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
523         { "init", cmd_init_db },
524         { "init-db", cmd_init_db },
525         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
526         { "log", cmd_log, RUN_SETUP },
527         { "ls-files", cmd_ls_files, RUN_SETUP },
528         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
529         { "ls-tree", cmd_ls_tree, RUN_SETUP },
530         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY | NO_PARSEOPT },
531         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
532         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
533         { "merge-base", cmd_merge_base, RUN_SETUP },
534         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
535         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
536         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
537         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
538         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
539         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
540         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
541         { "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
542         { "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
543         { "mktree", cmd_mktree, RUN_SETUP },
544         { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP_GENTLY },
545         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
546         { "name-rev", cmd_name_rev, RUN_SETUP },
547         { "notes", cmd_notes, RUN_SETUP },
548         { "pack-objects", cmd_pack_objects, RUN_SETUP },
549         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
550         { "pack-refs", cmd_pack_refs, RUN_SETUP },
551         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
552         { "pickaxe", cmd_blame, RUN_SETUP },
553         { "prune", cmd_prune, RUN_SETUP },
554         { "prune-packed", cmd_prune_packed, RUN_SETUP },
555         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
556         { "push", cmd_push, RUN_SETUP },
557         { "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
558         { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
559         { "rebase", cmd_rebase, RUN_SETUP | NEED_WORK_TREE },
560         { "rebase--interactive", cmd_rebase__interactive, RUN_SETUP | NEED_WORK_TREE },
561         { "receive-pack", cmd_receive_pack },
562         { "reflog", cmd_reflog, RUN_SETUP },
563         { "remote", cmd_remote, RUN_SETUP },
564         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
565         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
566         { "repack", cmd_repack, RUN_SETUP },
567         { "replace", cmd_replace, RUN_SETUP },
568         { "rerere", cmd_rerere, RUN_SETUP },
569         { "reset", cmd_reset, RUN_SETUP },
570         { "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
571         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
572         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
573         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
574         { "rm", cmd_rm, RUN_SETUP },
575         { "send-pack", cmd_send_pack, RUN_SETUP },
576         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
577         { "show", cmd_show, RUN_SETUP },
578         { "show-branch", cmd_show_branch, RUN_SETUP },
579         { "show-index", cmd_show_index, RUN_SETUP_GENTLY },
580         { "show-ref", cmd_show_ref, RUN_SETUP },
581         { "sparse-checkout", cmd_sparse_checkout, RUN_SETUP | NEED_WORK_TREE },
582         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
583         { "stash", cmd_stash, RUN_SETUP | NEED_WORK_TREE },
584         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
585         { "stripspace", cmd_stripspace },
586         { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
587         { "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
588         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
589         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
590         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
591         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
592         { "update-index", cmd_update_index, RUN_SETUP },
593         { "update-ref", cmd_update_ref, RUN_SETUP },
594         { "update-server-info", cmd_update_server_info, RUN_SETUP },
595         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
596         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
597         { "upload-pack", cmd_upload_pack },
598         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
599         { "verify-commit", cmd_verify_commit, RUN_SETUP },
600         { "verify-pack", cmd_verify_pack },
601         { "verify-tag", cmd_verify_tag, RUN_SETUP },
602         { "version", cmd_version },
603         { "whatchanged", cmd_whatchanged, RUN_SETUP },
604         { "worktree", cmd_worktree, RUN_SETUP | NO_PARSEOPT },
605         { "write-tree", cmd_write_tree, RUN_SETUP },
606 };
607
608 static struct cmd_struct *get_builtin(const char *s)
609 {
610         int i;
611         for (i = 0; i < ARRAY_SIZE(commands); i++) {
612                 struct cmd_struct *p = commands + i;
613                 if (!strcmp(s, p->cmd))
614                         return p;
615         }
616         return NULL;
617 }
618
619 int is_builtin(const char *s)
620 {
621         return !!get_builtin(s);
622 }
623
624 static void list_builtins(struct string_list *out, unsigned int exclude_option)
625 {
626         int i;
627         for (i = 0; i < ARRAY_SIZE(commands); i++) {
628                 if (exclude_option &&
629                     (commands[i].option & exclude_option))
630                         continue;
631                 string_list_append(out, commands[i].cmd);
632         }
633 }
634
635 #ifdef STRIP_EXTENSION
636 static void strip_extension(const char **argv)
637 {
638         size_t len;
639
640         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
641                 argv[0] = xmemdupz(argv[0], len);
642 }
643 #else
644 #define strip_extension(cmd)
645 #endif
646
647 static void handle_builtin(int argc, const char **argv)
648 {
649         struct argv_array args = ARGV_ARRAY_INIT;
650         const char *cmd;
651         struct cmd_struct *builtin;
652
653         strip_extension(argv);
654         cmd = argv[0];
655
656         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
657         if (argc > 1 && !strcmp(argv[1], "--help")) {
658                 int i;
659
660                 argv[1] = argv[0];
661                 argv[0] = cmd = "help";
662
663                 for (i = 0; i < argc; i++) {
664                         argv_array_push(&args, argv[i]);
665                         if (!i)
666                                 argv_array_push(&args, "--exclude-guides");
667                 }
668
669                 argc++;
670                 argv = args.argv;
671         }
672
673         builtin = get_builtin(cmd);
674         if (builtin)
675                 exit(run_builtin(builtin, argc, argv));
676         argv_array_clear(&args);
677 }
678
679 static void execv_dashed_external(const char **argv)
680 {
681         struct child_process cmd = CHILD_PROCESS_INIT;
682         int status;
683
684         if (get_super_prefix())
685                 die(_("%s doesn't support --super-prefix"), argv[0]);
686
687         if (use_pager == -1 && !is_builtin(argv[0]))
688                 use_pager = check_pager_config(argv[0]);
689         commit_pager_choice();
690
691         argv_array_pushf(&cmd.args, "git-%s", argv[0]);
692         argv_array_pushv(&cmd.args, argv + 1);
693         cmd.clean_on_exit = 1;
694         cmd.wait_after_clean = 1;
695         cmd.silent_exec_failure = 1;
696         cmd.trace2_child_class = "dashed";
697
698         trace2_cmd_name("_run_dashed_");
699
700         /*
701          * The code in run_command() logs trace2 child_start/child_exit
702          * events, so we do not need to report exec/exec_result events here.
703          */
704         trace_argv_printf(cmd.args.argv, "trace: exec:");
705
706         /*
707          * If we fail because the command is not found, it is
708          * OK to return. Otherwise, we just pass along the status code,
709          * or our usual generic code if we were not even able to exec
710          * the program.
711          */
712         status = run_command(&cmd);
713
714         /*
715          * If the child process ran and we are now going to exit, emit a
716          * generic string as our trace2 command verb to indicate that we
717          * launched a dashed command.
718          */
719         if (status >= 0)
720                 exit(status);
721         else if (errno != ENOENT)
722                 exit(128);
723 }
724
725 static int run_argv(int *argcp, const char ***argv)
726 {
727         int done_alias = 0;
728         struct string_list cmd_list = STRING_LIST_INIT_NODUP;
729         struct string_list_item *seen;
730
731         while (1) {
732                 /*
733                  * If we tried alias and futzed with our environment,
734                  * it no longer is safe to invoke builtins directly in
735                  * general.  We have to spawn them as dashed externals.
736                  *
737                  * NEEDSWORK: if we can figure out cases
738                  * where it is safe to do, we can avoid spawning a new
739                  * process.
740                  */
741                 if (!done_alias)
742                         handle_builtin(*argcp, *argv);
743                 else if (get_builtin(**argv)) {
744                         struct argv_array args = ARGV_ARRAY_INIT;
745                         int i;
746
747                         /*
748                          * The current process is committed to launching a
749                          * child process to run the command named in (**argv)
750                          * and exiting.  Log a generic string as the trace2
751                          * command verb to indicate this.  Note that the child
752                          * process will log the actual verb when it runs.
753                          */
754                         trace2_cmd_name("_run_git_alias_");
755
756                         if (get_super_prefix())
757                                 die("%s doesn't support --super-prefix", **argv);
758
759                         commit_pager_choice();
760
761                         argv_array_push(&args, "git");
762                         for (i = 0; i < *argcp; i++)
763                                 argv_array_push(&args, (*argv)[i]);
764
765                         trace_argv_printf(args.argv, "trace: exec:");
766
767                         /*
768                          * if we fail because the command is not found, it is
769                          * OK to return. Otherwise, we just pass along the status code.
770                          */
771                         i = run_command_v_opt_tr2(args.argv, RUN_SILENT_EXEC_FAILURE |
772                                                   RUN_CLEAN_ON_EXIT | RUN_WAIT_AFTER_CLEAN, "git_alias");
773                         if (i >= 0 || errno != ENOENT)
774                                 exit(i);
775                         die("could not execute builtin %s", **argv);
776                 }
777
778                 /* .. then try the external ones */
779                 execv_dashed_external(*argv);
780
781                 seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
782                 if (seen) {
783                         int i;
784                         struct strbuf sb = STRBUF_INIT;
785                         for (i = 0; i < cmd_list.nr; i++) {
786                                 struct string_list_item *item = &cmd_list.items[i];
787
788                                 strbuf_addf(&sb, "\n  %s", item->string);
789                                 if (item == seen)
790                                         strbuf_addstr(&sb, " <==");
791                                 else if (i == cmd_list.nr - 1)
792                                         strbuf_addstr(&sb, " ==>");
793                         }
794                         die(_("alias loop detected: expansion of '%s' does"
795                               " not terminate:%s"), cmd_list.items[0].string, sb.buf);
796                 }
797
798                 string_list_append(&cmd_list, *argv[0]);
799
800                 /*
801                  * It could be an alias -- this works around the insanity
802                  * of overriding "git log" with "git show" by having
803                  * alias.log = show
804                  */
805                 if (!handle_alias(argcp, argv))
806                         break;
807                 done_alias = 1;
808         }
809
810         string_list_clear(&cmd_list, 0);
811
812         return done_alias;
813 }
814
815 int cmd_main(int argc, const char **argv)
816 {
817         const char *cmd;
818         int done_help = 0;
819
820         cmd = argv[0];
821         if (!cmd)
822                 cmd = "git-help";
823         else {
824                 const char *slash = find_last_dir_sep(cmd);
825                 if (slash)
826                         cmd = slash + 1;
827         }
828
829         trace_command_performance(argv);
830
831         /*
832          * "git-xxxx" is the same as "git xxxx", but we obviously:
833          *
834          *  - cannot take flags in between the "git" and the "xxxx".
835          *  - cannot execute it externally (since it would just do
836          *    the same thing over again)
837          *
838          * So we just directly call the builtin handler, and die if
839          * that one cannot handle it.
840          */
841         if (skip_prefix(cmd, "git-", &cmd)) {
842                 argv[0] = cmd;
843                 handle_builtin(argc, argv);
844                 die(_("cannot handle %s as a builtin"), cmd);
845         }
846
847         /* Look for flags.. */
848         argv++;
849         argc--;
850         handle_options(&argv, &argc, NULL);
851         if (argc > 0) {
852                 /* translate --help and --version into commands */
853                 skip_prefix(argv[0], "--", &argv[0]);
854         } else {
855                 /* The user didn't specify a command; give them help */
856                 commit_pager_choice();
857                 printf(_("usage: %s\n\n"), git_usage_string);
858                 list_common_cmds_help();
859                 printf("\n%s\n", _(git_more_info_string));
860                 exit(1);
861         }
862         cmd = argv[0];
863
864         /*
865          * We use PATH to find git commands, but we prepend some higher
866          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
867          * environment, and the $(gitexecdir) from the Makefile at build
868          * time.
869          */
870         setup_path();
871
872         while (1) {
873                 int was_alias = run_argv(&argc, &argv);
874                 if (errno != ENOENT)
875                         break;
876                 if (was_alias) {
877                         fprintf(stderr, _("expansion of alias '%s' failed; "
878                                           "'%s' is not a git command\n"),
879                                 cmd, argv[0]);
880                         exit(1);
881                 }
882                 if (!done_help) {
883                         cmd = argv[0] = help_unknown_cmd(cmd);
884                         done_help = 1;
885                 } else
886                         break;
887         }
888
889         fprintf(stderr, _("failed to run command '%s': %s\n"),
890                 cmd, strerror(errno));
891
892         return 1;
893 }