Merge branch 'sb/worktree-remove-opt-force'
[git] / builtin / fsck.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "repository.h"
4 #include "config.h"
5 #include "commit.h"
6 #include "tree.h"
7 #include "blob.h"
8 #include "tag.h"
9 #include "refs.h"
10 #include "pack.h"
11 #include "cache-tree.h"
12 #include "tree-walk.h"
13 #include "fsck.h"
14 #include "parse-options.h"
15 #include "dir.h"
16 #include "progress.h"
17 #include "streaming.h"
18 #include "decorate.h"
19 #include "packfile.h"
20 #include "object-store.h"
21
22 #define REACHABLE 0x0001
23 #define SEEN      0x0002
24 #define HAS_OBJ   0x0004
25 /* This flag is set if something points to this object. */
26 #define USED      0x0008
27
28 static int show_root;
29 static int show_tags;
30 static int show_unreachable;
31 static int include_reflogs = 1;
32 static int check_full = 1;
33 static int connectivity_only;
34 static int check_strict;
35 static int keep_cache_objects;
36 static struct fsck_options fsck_walk_options = FSCK_OPTIONS_DEFAULT;
37 static struct fsck_options fsck_obj_options = FSCK_OPTIONS_DEFAULT;
38 static struct object_id head_oid;
39 static const char *head_points_at;
40 static int errors_found;
41 static int write_lost_and_found;
42 static int verbose;
43 static int show_progress = -1;
44 static int show_dangling = 1;
45 static int name_objects;
46 #define ERROR_OBJECT 01
47 #define ERROR_REACHABLE 02
48 #define ERROR_PACK 04
49 #define ERROR_REFS 010
50
51 static const char *describe_object(struct object *obj)
52 {
53         static struct strbuf buf = STRBUF_INIT;
54         char *name = name_objects ?
55                 lookup_decoration(fsck_walk_options.object_names, obj) : NULL;
56
57         strbuf_reset(&buf);
58         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
59         if (name)
60                 strbuf_addf(&buf, " (%s)", name);
61
62         return buf.buf;
63 }
64
65 static const char *printable_type(struct object *obj)
66 {
67         const char *ret;
68
69         if (obj->type == OBJ_NONE) {
70                 enum object_type type = oid_object_info(&obj->oid, NULL);
71                 if (type > 0)
72                         object_as_type(obj, type, 0);
73         }
74
75         ret = type_name(obj->type);
76         if (!ret)
77                 ret = "unknown";
78
79         return ret;
80 }
81
82 static int fsck_config(const char *var, const char *value, void *cb)
83 {
84         if (strcmp(var, "fsck.skiplist") == 0) {
85                 const char *path;
86                 struct strbuf sb = STRBUF_INIT;
87
88                 if (git_config_pathname(&path, var, value))
89                         return 1;
90                 strbuf_addf(&sb, "skiplist=%s", path);
91                 free((char *)path);
92                 fsck_set_msg_types(&fsck_obj_options, sb.buf);
93                 strbuf_release(&sb);
94                 return 0;
95         }
96
97         if (skip_prefix(var, "fsck.", &var)) {
98                 fsck_set_msg_type(&fsck_obj_options, var, value);
99                 return 0;
100         }
101
102         return git_default_config(var, value, cb);
103 }
104
105 static void objreport(struct object *obj, const char *msg_type,
106                         const char *err)
107 {
108         fprintf(stderr, "%s in %s %s: %s\n",
109                 msg_type, printable_type(obj), describe_object(obj), err);
110 }
111
112 static int objerror(struct object *obj, const char *err)
113 {
114         errors_found |= ERROR_OBJECT;
115         objreport(obj, "error", err);
116         return -1;
117 }
118
119 static int fsck_error_func(struct fsck_options *o,
120         struct object *obj, int type, const char *message)
121 {
122         objreport(obj, (type == FSCK_WARN) ? "warning" : "error", message);
123         return (type == FSCK_WARN) ? 0 : 1;
124 }
125
126 static struct object_array pending;
127
128 static int mark_object(struct object *obj, int type, void *data, struct fsck_options *options)
129 {
130         struct object *parent = data;
131
132         /*
133          * The only case data is NULL or type is OBJ_ANY is when
134          * mark_object_reachable() calls us.  All the callers of
135          * that function has non-NULL obj hence ...
136          */
137         if (!obj) {
138                 /* ... these references to parent->fld are safe here */
139                 printf("broken link from %7s %s\n",
140                            printable_type(parent), describe_object(parent));
141                 printf("broken link from %7s %s\n",
142                            (type == OBJ_ANY ? "unknown" : type_name(type)), "unknown");
143                 errors_found |= ERROR_REACHABLE;
144                 return 1;
145         }
146
147         if (type != OBJ_ANY && obj->type != type)
148                 /* ... and the reference to parent is safe here */
149                 objerror(parent, "wrong object type in link");
150
151         if (obj->flags & REACHABLE)
152                 return 0;
153         obj->flags |= REACHABLE;
154
155         if (is_promisor_object(&obj->oid))
156                 /*
157                  * Further recursion does not need to be performed on this
158                  * object since it is a promisor object (so it does not need to
159                  * be added to "pending").
160                  */
161                 return 0;
162
163         if (!(obj->flags & HAS_OBJ)) {
164                 if (parent && !has_object_file(&obj->oid)) {
165                         printf("broken link from %7s %s\n",
166                                  printable_type(parent), describe_object(parent));
167                         printf("              to %7s %s\n",
168                                  printable_type(obj), describe_object(obj));
169                         errors_found |= ERROR_REACHABLE;
170                 }
171                 return 1;
172         }
173
174         add_object_array(obj, NULL, &pending);
175         return 0;
176 }
177
178 static void mark_object_reachable(struct object *obj)
179 {
180         mark_object(obj, OBJ_ANY, NULL, NULL);
181 }
182
183 static int traverse_one_object(struct object *obj)
184 {
185         int result = fsck_walk(obj, obj, &fsck_walk_options);
186
187         if (obj->type == OBJ_TREE) {
188                 struct tree *tree = (struct tree *)obj;
189                 free_tree_buffer(tree);
190         }
191         return result;
192 }
193
194 static int traverse_reachable(void)
195 {
196         struct progress *progress = NULL;
197         unsigned int nr = 0;
198         int result = 0;
199         if (show_progress)
200                 progress = start_delayed_progress(_("Checking connectivity"), 0);
201         while (pending.nr) {
202                 result |= traverse_one_object(object_array_pop(&pending));
203                 display_progress(progress, ++nr);
204         }
205         stop_progress(&progress);
206         return !!result;
207 }
208
209 static int mark_used(struct object *obj, int type, void *data, struct fsck_options *options)
210 {
211         if (!obj)
212                 return 1;
213         obj->flags |= USED;
214         return 0;
215 }
216
217 /*
218  * Check a single reachable object
219  */
220 static void check_reachable_object(struct object *obj)
221 {
222         /*
223          * We obviously want the object to be parsed,
224          * except if it was in a pack-file and we didn't
225          * do a full fsck
226          */
227         if (!(obj->flags & HAS_OBJ)) {
228                 if (is_promisor_object(&obj->oid))
229                         return;
230                 if (has_sha1_pack(obj->oid.hash))
231                         return; /* it is in pack - forget about it */
232                 printf("missing %s %s\n", printable_type(obj),
233                         describe_object(obj));
234                 errors_found |= ERROR_REACHABLE;
235                 return;
236         }
237 }
238
239 /*
240  * Check a single unreachable object
241  */
242 static void check_unreachable_object(struct object *obj)
243 {
244         /*
245          * Missing unreachable object? Ignore it. It's not like
246          * we miss it (since it can't be reached), nor do we want
247          * to complain about it being unreachable (since it does
248          * not exist).
249          */
250         if (!(obj->flags & HAS_OBJ))
251                 return;
252
253         /*
254          * Unreachable object that exists? Show it if asked to,
255          * since this is something that is prunable.
256          */
257         if (show_unreachable) {
258                 printf("unreachable %s %s\n", printable_type(obj),
259                         describe_object(obj));
260                 return;
261         }
262
263         /*
264          * "!USED" means that nothing at all points to it, including
265          * other unreachable objects. In other words, it's the "tip"
266          * of some set of unreachable objects, usually a commit that
267          * got dropped.
268          *
269          * Such starting points are more interesting than some random
270          * set of unreachable objects, so we show them even if the user
271          * hasn't asked for _all_ unreachable objects. If you have
272          * deleted a branch by mistake, this is a prime candidate to
273          * start looking at, for example.
274          */
275         if (!(obj->flags & USED)) {
276                 if (show_dangling)
277                         printf("dangling %s %s\n", printable_type(obj),
278                                describe_object(obj));
279                 if (write_lost_and_found) {
280                         char *filename = git_pathdup("lost-found/%s/%s",
281                                 obj->type == OBJ_COMMIT ? "commit" : "other",
282                                 describe_object(obj));
283                         FILE *f;
284
285                         if (safe_create_leading_directories_const(filename)) {
286                                 error("Could not create lost-found");
287                                 free(filename);
288                                 return;
289                         }
290                         f = xfopen(filename, "w");
291                         if (obj->type == OBJ_BLOB) {
292                                 if (stream_blob_to_fd(fileno(f), &obj->oid, NULL, 1))
293                                         die_errno("Could not write '%s'", filename);
294                         } else
295                                 fprintf(f, "%s\n", describe_object(obj));
296                         if (fclose(f))
297                                 die_errno("Could not finish '%s'",
298                                           filename);
299                         free(filename);
300                 }
301                 return;
302         }
303
304         /*
305          * Otherwise? It's there, it's unreachable, and some other unreachable
306          * object points to it. Ignore it - it's not interesting, and we showed
307          * all the interesting cases above.
308          */
309 }
310
311 static void check_object(struct object *obj)
312 {
313         if (verbose)
314                 fprintf(stderr, "Checking %s\n", describe_object(obj));
315
316         if (obj->flags & REACHABLE)
317                 check_reachable_object(obj);
318         else
319                 check_unreachable_object(obj);
320 }
321
322 static void check_connectivity(void)
323 {
324         int i, max;
325
326         /* Traverse the pending reachable objects */
327         traverse_reachable();
328
329         /* Look up all the requirements, warn about missing objects.. */
330         max = get_max_object_index();
331         if (verbose)
332                 fprintf(stderr, "Checking connectivity (%d objects)\n", max);
333
334         for (i = 0; i < max; i++) {
335                 struct object *obj = get_indexed_object(i);
336
337                 if (obj)
338                         check_object(obj);
339         }
340 }
341
342 static int fsck_obj(struct object *obj)
343 {
344         int err;
345
346         if (obj->flags & SEEN)
347                 return 0;
348         obj->flags |= SEEN;
349
350         if (verbose)
351                 fprintf(stderr, "Checking %s %s\n",
352                         printable_type(obj), describe_object(obj));
353
354         if (fsck_walk(obj, NULL, &fsck_obj_options))
355                 objerror(obj, "broken links");
356         err = fsck_object(obj, NULL, 0, &fsck_obj_options);
357         if (err)
358                 goto out;
359
360         if (obj->type == OBJ_COMMIT) {
361                 struct commit *commit = (struct commit *) obj;
362
363                 if (!commit->parents && show_root)
364                         printf("root %s\n", describe_object(&commit->object));
365         }
366
367         if (obj->type == OBJ_TAG) {
368                 struct tag *tag = (struct tag *) obj;
369
370                 if (show_tags && tag->tagged) {
371                         printf("tagged %s %s", printable_type(tag->tagged),
372                                 describe_object(tag->tagged));
373                         printf(" (%s) in %s\n", tag->tag,
374                                 describe_object(&tag->object));
375                 }
376         }
377
378 out:
379         if (obj->type == OBJ_TREE)
380                 free_tree_buffer((struct tree *)obj);
381         if (obj->type == OBJ_COMMIT)
382                 free_commit_buffer((struct commit *)obj);
383         return err;
384 }
385
386 static int fsck_obj_buffer(const struct object_id *oid, enum object_type type,
387                            unsigned long size, void *buffer, int *eaten)
388 {
389         /*
390          * Note, buffer may be NULL if type is OBJ_BLOB. See
391          * verify_packfile(), data_valid variable for details.
392          */
393         struct object *obj;
394         obj = parse_object_buffer(oid, type, size, buffer, eaten);
395         if (!obj) {
396                 errors_found |= ERROR_OBJECT;
397                 return error("%s: object corrupt or missing", oid_to_hex(oid));
398         }
399         obj->flags &= ~(REACHABLE | SEEN);
400         obj->flags |= HAS_OBJ;
401         return fsck_obj(obj);
402 }
403
404 static int default_refs;
405
406 static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
407         timestamp_t timestamp)
408 {
409         struct object *obj;
410
411         if (!is_null_oid(oid)) {
412                 obj = lookup_object(oid->hash);
413                 if (obj && (obj->flags & HAS_OBJ)) {
414                         if (timestamp && name_objects)
415                                 add_decoration(fsck_walk_options.object_names,
416                                         obj,
417                                         xstrfmt("%s@{%"PRItime"}", refname, timestamp));
418                         obj->flags |= USED;
419                         mark_object_reachable(obj);
420                 } else if (!is_promisor_object(oid)) {
421                         error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
422                         errors_found |= ERROR_REACHABLE;
423                 }
424         }
425 }
426
427 static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid,
428                 const char *email, timestamp_t timestamp, int tz,
429                 const char *message, void *cb_data)
430 {
431         const char *refname = cb_data;
432
433         if (verbose)
434                 fprintf(stderr, "Checking reflog %s->%s\n",
435                         oid_to_hex(ooid), oid_to_hex(noid));
436
437         fsck_handle_reflog_oid(refname, ooid, 0);
438         fsck_handle_reflog_oid(refname, noid, timestamp);
439         return 0;
440 }
441
442 static int fsck_handle_reflog(const char *logname, const struct object_id *oid,
443                               int flag, void *cb_data)
444 {
445         for_each_reflog_ent(logname, fsck_handle_reflog_ent, (void *)logname);
446         return 0;
447 }
448
449 static int fsck_handle_ref(const char *refname, const struct object_id *oid,
450                            int flag, void *cb_data)
451 {
452         struct object *obj;
453
454         obj = parse_object(oid);
455         if (!obj) {
456                 if (is_promisor_object(oid)) {
457                         /*
458                          * Increment default_refs anyway, because this is a
459                          * valid ref.
460                          */
461                          default_refs++;
462                          return 0;
463                 }
464                 error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
465                 errors_found |= ERROR_REACHABLE;
466                 /* We'll continue with the rest despite the error.. */
467                 return 0;
468         }
469         if (obj->type != OBJ_COMMIT && is_branch(refname)) {
470                 error("%s: not a commit", refname);
471                 errors_found |= ERROR_REFS;
472         }
473         default_refs++;
474         obj->flags |= USED;
475         if (name_objects)
476                 add_decoration(fsck_walk_options.object_names,
477                         obj, xstrdup(refname));
478         mark_object_reachable(obj);
479
480         return 0;
481 }
482
483 static void get_default_heads(void)
484 {
485         if (head_points_at && !is_null_oid(&head_oid))
486                 fsck_handle_ref("HEAD", &head_oid, 0, NULL);
487         for_each_rawref(fsck_handle_ref, NULL);
488         if (include_reflogs)
489                 for_each_reflog(fsck_handle_reflog, NULL);
490
491         /*
492          * Not having any default heads isn't really fatal, but
493          * it does mean that "--unreachable" no longer makes any
494          * sense (since in this case everything will obviously
495          * be unreachable by definition.
496          *
497          * Showing dangling objects is valid, though (as those
498          * dangling objects are likely lost heads).
499          *
500          * So we just print a warning about it, and clear the
501          * "show_unreachable" flag.
502          */
503         if (!default_refs) {
504                 fprintf(stderr, "notice: No default references\n");
505                 show_unreachable = 0;
506         }
507 }
508
509 static struct object *parse_loose_object(const struct object_id *oid,
510                                          const char *path)
511 {
512         struct object *obj;
513         void *contents;
514         enum object_type type;
515         unsigned long size;
516         int eaten;
517
518         if (read_loose_object(path, oid, &type, &size, &contents) < 0)
519                 return NULL;
520
521         if (!contents && type != OBJ_BLOB)
522                 die("BUG: read_loose_object streamed a non-blob");
523
524         obj = parse_object_buffer(oid, type, size, contents, &eaten);
525
526         if (!eaten)
527                 free(contents);
528         return obj;
529 }
530
531 static int fsck_loose(const struct object_id *oid, const char *path, void *data)
532 {
533         struct object *obj = parse_loose_object(oid, path);
534
535         if (!obj) {
536                 errors_found |= ERROR_OBJECT;
537                 error("%s: object corrupt or missing: %s",
538                       oid_to_hex(oid), path);
539                 return 0; /* keep checking other objects */
540         }
541
542         obj->flags &= ~(REACHABLE | SEEN);
543         obj->flags |= HAS_OBJ;
544         if (fsck_obj(obj))
545                 errors_found |= ERROR_OBJECT;
546         return 0;
547 }
548
549 static int fsck_cruft(const char *basename, const char *path, void *data)
550 {
551         if (!starts_with(basename, "tmp_obj_"))
552                 fprintf(stderr, "bad sha1 file: %s\n", path);
553         return 0;
554 }
555
556 static int fsck_subdir(unsigned int nr, const char *path, void *progress)
557 {
558         display_progress(progress, nr + 1);
559         return 0;
560 }
561
562 static void fsck_object_dir(const char *path)
563 {
564         struct progress *progress = NULL;
565
566         if (verbose)
567                 fprintf(stderr, "Checking object directory\n");
568
569         if (show_progress)
570                 progress = start_progress(_("Checking object directories"), 256);
571
572         for_each_loose_file_in_objdir(path, fsck_loose, fsck_cruft, fsck_subdir,
573                                       progress);
574         display_progress(progress, 256);
575         stop_progress(&progress);
576 }
577
578 static int fsck_head_link(void)
579 {
580         int null_is_error = 0;
581
582         if (verbose)
583                 fprintf(stderr, "Checking HEAD link\n");
584
585         head_points_at = resolve_ref_unsafe("HEAD", 0, &head_oid, NULL);
586         if (!head_points_at) {
587                 errors_found |= ERROR_REFS;
588                 return error("Invalid HEAD");
589         }
590         if (!strcmp(head_points_at, "HEAD"))
591                 /* detached HEAD */
592                 null_is_error = 1;
593         else if (!starts_with(head_points_at, "refs/heads/")) {
594                 errors_found |= ERROR_REFS;
595                 return error("HEAD points to something strange (%s)",
596                              head_points_at);
597         }
598         if (is_null_oid(&head_oid)) {
599                 if (null_is_error) {
600                         errors_found |= ERROR_REFS;
601                         return error("HEAD: detached HEAD points at nothing");
602                 }
603                 fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
604                         head_points_at + 11);
605         }
606         return 0;
607 }
608
609 static int fsck_cache_tree(struct cache_tree *it)
610 {
611         int i;
612         int err = 0;
613
614         if (verbose)
615                 fprintf(stderr, "Checking cache tree\n");
616
617         if (0 <= it->entry_count) {
618                 struct object *obj = parse_object(&it->oid);
619                 if (!obj) {
620                         error("%s: invalid sha1 pointer in cache-tree",
621                               oid_to_hex(&it->oid));
622                         errors_found |= ERROR_REFS;
623                         return 1;
624                 }
625                 obj->flags |= USED;
626                 if (name_objects)
627                         add_decoration(fsck_walk_options.object_names,
628                                 obj, xstrdup(":"));
629                 mark_object_reachable(obj);
630                 if (obj->type != OBJ_TREE)
631                         err |= objerror(obj, "non-tree in cache-tree");
632         }
633         for (i = 0; i < it->subtree_nr; i++)
634                 err |= fsck_cache_tree(it->down[i]->cache_tree);
635         return err;
636 }
637
638 static void mark_object_for_connectivity(const struct object_id *oid)
639 {
640         struct object *obj = lookup_unknown_object(oid->hash);
641         obj->flags |= HAS_OBJ;
642 }
643
644 static int mark_loose_for_connectivity(const struct object_id *oid,
645                                        const char *path,
646                                        void *data)
647 {
648         mark_object_for_connectivity(oid);
649         return 0;
650 }
651
652 static int mark_packed_for_connectivity(const struct object_id *oid,
653                                         struct packed_git *pack,
654                                         uint32_t pos,
655                                         void *data)
656 {
657         mark_object_for_connectivity(oid);
658         return 0;
659 }
660
661 static char const * const fsck_usage[] = {
662         N_("git fsck [<options>] [<object>...]"),
663         NULL
664 };
665
666 static struct option fsck_opts[] = {
667         OPT__VERBOSE(&verbose, N_("be verbose")),
668         OPT_BOOL(0, "unreachable", &show_unreachable, N_("show unreachable objects")),
669         OPT_BOOL(0, "dangling", &show_dangling, N_("show dangling objects")),
670         OPT_BOOL(0, "tags", &show_tags, N_("report tags")),
671         OPT_BOOL(0, "root", &show_root, N_("report root nodes")),
672         OPT_BOOL(0, "cache", &keep_cache_objects, N_("make index objects head nodes")),
673         OPT_BOOL(0, "reflogs", &include_reflogs, N_("make reflogs head nodes (default)")),
674         OPT_BOOL(0, "full", &check_full, N_("also consider packs and alternate objects")),
675         OPT_BOOL(0, "connectivity-only", &connectivity_only, N_("check only connectivity")),
676         OPT_BOOL(0, "strict", &check_strict, N_("enable more strict checking")),
677         OPT_BOOL(0, "lost-found", &write_lost_and_found,
678                                 N_("write dangling objects in .git/lost-found")),
679         OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
680         OPT_BOOL(0, "name-objects", &name_objects, N_("show verbose names for reachable objects")),
681         OPT_END(),
682 };
683
684 int cmd_fsck(int argc, const char **argv, const char *prefix)
685 {
686         int i;
687         struct alternate_object_database *alt;
688
689         /* fsck knows how to handle missing promisor objects */
690         fetch_if_missing = 0;
691
692         errors_found = 0;
693         check_replace_refs = 0;
694
695         argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
696
697         fsck_walk_options.walk = mark_object;
698         fsck_obj_options.walk = mark_used;
699         fsck_obj_options.error_func = fsck_error_func;
700         if (check_strict)
701                 fsck_obj_options.strict = 1;
702
703         if (show_progress == -1)
704                 show_progress = isatty(2);
705         if (verbose)
706                 show_progress = 0;
707
708         if (write_lost_and_found) {
709                 check_full = 1;
710                 include_reflogs = 0;
711         }
712
713         if (name_objects)
714                 fsck_walk_options.object_names =
715                         xcalloc(1, sizeof(struct decoration));
716
717         git_config(fsck_config, NULL);
718
719         fsck_head_link();
720         if (connectivity_only) {
721                 for_each_loose_object(mark_loose_for_connectivity, NULL, 0);
722                 for_each_packed_object(mark_packed_for_connectivity, NULL, 0);
723         } else {
724                 struct alternate_object_database *alt_odb_list;
725
726                 fsck_object_dir(get_object_directory());
727
728                 prepare_alt_odb(the_repository);
729                 alt_odb_list = the_repository->objects->alt_odb_list;
730                 for (alt = alt_odb_list; alt; alt = alt->next)
731                         fsck_object_dir(alt->path);
732
733                 if (check_full) {
734                         struct packed_git *p;
735                         uint32_t total = 0, count = 0;
736                         struct progress *progress = NULL;
737
738                         if (show_progress) {
739                                 for (p = get_packed_git(the_repository); p;
740                                      p = p->next) {
741                                         if (open_pack_index(p))
742                                                 continue;
743                                         total += p->num_objects;
744                                 }
745
746                                 progress = start_progress(_("Checking objects"), total);
747                         }
748                         for (p = get_packed_git(the_repository); p;
749                              p = p->next) {
750                                 /* verify gives error messages itself */
751                                 if (verify_pack(p, fsck_obj_buffer,
752                                                 progress, count))
753                                         errors_found |= ERROR_PACK;
754                                 count += p->num_objects;
755                         }
756                         stop_progress(&progress);
757                 }
758         }
759
760         for (i = 0; i < argc; i++) {
761                 const char *arg = argv[i];
762                 struct object_id oid;
763                 if (!get_oid(arg, &oid)) {
764                         struct object *obj = lookup_object(oid.hash);
765
766                         if (!obj || !(obj->flags & HAS_OBJ)) {
767                                 if (is_promisor_object(&oid))
768                                         continue;
769                                 error("%s: object missing", oid_to_hex(&oid));
770                                 errors_found |= ERROR_OBJECT;
771                                 continue;
772                         }
773
774                         obj->flags |= USED;
775                         if (name_objects)
776                                 add_decoration(fsck_walk_options.object_names,
777                                         obj, xstrdup(arg));
778                         mark_object_reachable(obj);
779                         continue;
780                 }
781                 error("invalid parameter: expected sha1, got '%s'", arg);
782                 errors_found |= ERROR_OBJECT;
783         }
784
785         /*
786          * If we've not been given any explicit head information, do the
787          * default ones from .git/refs. We also consider the index file
788          * in this case (ie this implies --cache).
789          */
790         if (!argc) {
791                 get_default_heads();
792                 keep_cache_objects = 1;
793         }
794
795         if (keep_cache_objects) {
796                 verify_index_checksum = 1;
797                 verify_ce_order = 1;
798                 read_cache();
799                 for (i = 0; i < active_nr; i++) {
800                         unsigned int mode;
801                         struct blob *blob;
802                         struct object *obj;
803
804                         mode = active_cache[i]->ce_mode;
805                         if (S_ISGITLINK(mode))
806                                 continue;
807                         blob = lookup_blob(&active_cache[i]->oid);
808                         if (!blob)
809                                 continue;
810                         obj = &blob->object;
811                         obj->flags |= USED;
812                         if (name_objects)
813                                 add_decoration(fsck_walk_options.object_names,
814                                         obj,
815                                         xstrfmt(":%s", active_cache[i]->name));
816                         mark_object_reachable(obj);
817                 }
818                 if (active_cache_tree)
819                         fsck_cache_tree(active_cache_tree);
820         }
821
822         check_connectivity();
823         return errors_found;
824 }