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