Create pack_report() as a debugging aid.
[git] / fsck-objects.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "tree.h"
4 #include "blob.h"
5 #include "tag.h"
6 #include "refs.h"
7 #include "pack.h"
8 #include "cache-tree.h"
9 #include "tree-walk.h"
10
11 #define REACHABLE 0x0001
12 #define SEEN      0x0002
13
14 static int show_root;
15 static int show_tags;
16 static int show_unreachable;
17 static int check_full;
18 static int check_strict;
19 static int keep_cache_objects;
20 static unsigned char head_sha1[20];
21
22 #ifdef NO_D_INO_IN_DIRENT
23 #define SORT_DIRENT 0
24 #define DIRENT_SORT_HINT(de) 0
25 #else
26 #define SORT_DIRENT 1
27 #define DIRENT_SORT_HINT(de) ((de)->d_ino)
28 #endif
29
30 static void objreport(struct object *obj, const char *severity,
31                       const char *err, va_list params)
32 {
33         fprintf(stderr, "%s in %s %s: ",
34                 severity, typename(obj->type), sha1_to_hex(obj->sha1));
35         vfprintf(stderr, err, params);
36         fputs("\n", stderr);
37 }
38
39 static int objerror(struct object *obj, const char *err, ...)
40 {
41         va_list params;
42         va_start(params, err);
43         objreport(obj, "error", err, params);
44         va_end(params);
45         return -1;
46 }
47
48 static int objwarning(struct object *obj, const char *err, ...)
49 {
50         va_list params;
51         va_start(params, err);
52         objreport(obj, "warning", err, params);
53         va_end(params);
54         return -1;
55 }
56
57
58 static void check_connectivity(void)
59 {
60         int i, max;
61
62         /* Look up all the requirements, warn about missing objects.. */
63         max = get_max_object_index();
64         for (i = 0; i < max; i++) {
65                 const struct object_refs *refs;
66                 struct object *obj = get_indexed_object(i);
67
68                 if (!obj)
69                         continue;
70
71                 if (!obj->parsed) {
72                         if (has_sha1_file(obj->sha1))
73                                 ; /* it is in pack */
74                         else
75                                 printf("missing %s %s\n",
76                                        typename(obj->type), sha1_to_hex(obj->sha1));
77                         continue;
78                 }
79
80                 refs = lookup_object_refs(obj);
81                 if (refs) {
82                         unsigned j;
83                         for (j = 0; j < refs->count; j++) {
84                                 struct object *ref = refs->ref[j];
85                                 if (ref->parsed ||
86                                     (has_sha1_file(ref->sha1)))
87                                         continue;
88                                 printf("broken link from %7s %s\n",
89                                        typename(obj->type), sha1_to_hex(obj->sha1));
90                                 printf("              to %7s %s\n",
91                                        typename(ref->type), sha1_to_hex(ref->sha1));
92                         }
93                 }
94
95                 if (show_unreachable && !(obj->flags & REACHABLE)) {
96                         printf("unreachable %s %s\n",
97                                typename(obj->type), sha1_to_hex(obj->sha1));
98                         continue;
99                 }
100
101                 if (!obj->used) {
102                         printf("dangling %s %s\n", typename(obj->type),
103                                sha1_to_hex(obj->sha1));
104                 }
105         }
106 }
107
108 /*
109  * The entries in a tree are ordered in the _path_ order,
110  * which means that a directory entry is ordered by adding
111  * a slash to the end of it.
112  *
113  * So a directory called "a" is ordered _after_ a file
114  * called "a.c", because "a/" sorts after "a.c".
115  */
116 #define TREE_UNORDERED (-1)
117 #define TREE_HAS_DUPS  (-2)
118
119 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
120 {
121         int len1 = strlen(name1);
122         int len2 = strlen(name2);
123         int len = len1 < len2 ? len1 : len2;
124         unsigned char c1, c2;
125         int cmp;
126
127         cmp = memcmp(name1, name2, len);
128         if (cmp < 0)
129                 return 0;
130         if (cmp > 0)
131                 return TREE_UNORDERED;
132
133         /*
134          * Ok, the first <len> characters are the same.
135          * Now we need to order the next one, but turn
136          * a '\0' into a '/' for a directory entry.
137          */
138         c1 = name1[len];
139         c2 = name2[len];
140         if (!c1 && !c2)
141                 /*
142                  * git-write-tree used to write out a nonsense tree that has
143                  * entries with the same name, one blob and one tree.  Make
144                  * sure we do not have duplicate entries.
145                  */
146                 return TREE_HAS_DUPS;
147         if (!c1 && S_ISDIR(mode1))
148                 c1 = '/';
149         if (!c2 && S_ISDIR(mode2))
150                 c2 = '/';
151         return c1 < c2 ? 0 : TREE_UNORDERED;
152 }
153
154 static int fsck_tree(struct tree *item)
155 {
156         int retval;
157         int has_full_path = 0;
158         int has_zero_pad = 0;
159         int has_bad_modes = 0;
160         int has_dup_entries = 0;
161         int not_properly_sorted = 0;
162         struct tree_desc desc;
163         unsigned o_mode;
164         const char *o_name;
165         const unsigned char *o_sha1;
166
167         desc.buf = item->buffer;
168         desc.size = item->size;
169
170         o_mode = 0;
171         o_name = NULL;
172         o_sha1 = NULL;
173         while (desc.size) {
174                 unsigned mode;
175                 const char *name;
176                 const unsigned char *sha1;
177
178                 sha1 = tree_entry_extract(&desc, &name, &mode);
179
180                 if (strchr(name, '/'))
181                         has_full_path = 1;
182                 has_zero_pad |= *(char *)desc.buf == '0';
183                 update_tree_entry(&desc);
184
185                 switch (mode) {
186                 /*
187                  * Standard modes..
188                  */
189                 case S_IFREG | 0755:
190                 case S_IFREG | 0644:
191                 case S_IFLNK:
192                 case S_IFDIR:
193                         break;
194                 /*
195                  * This is nonstandard, but we had a few of these
196                  * early on when we honored the full set of mode
197                  * bits..
198                  */
199                 case S_IFREG | 0664:
200                         if (!check_strict)
201                                 break;
202                 default:
203                         has_bad_modes = 1;
204                 }
205
206                 if (o_name) {
207                         switch (verify_ordered(o_mode, o_name, mode, name)) {
208                         case TREE_UNORDERED:
209                                 not_properly_sorted = 1;
210                                 break;
211                         case TREE_HAS_DUPS:
212                                 has_dup_entries = 1;
213                                 break;
214                         default:
215                                 break;
216                         }
217                 }
218
219                 o_mode = mode;
220                 o_name = name;
221                 o_sha1 = sha1;
222         }
223         free(item->buffer);
224         item->buffer = NULL;
225
226         retval = 0;
227         if (has_full_path) {
228                 objwarning(&item->object, "contains full pathnames");
229         }
230         if (has_zero_pad) {
231                 objwarning(&item->object, "contains zero-padded file modes");
232         }
233         if (has_bad_modes) {
234                 objwarning(&item->object, "contains bad file modes");
235         }
236         if (has_dup_entries) {
237                 retval = objerror(&item->object, "contains duplicate file entries");
238         }
239         if (not_properly_sorted) {
240                 retval = objerror(&item->object, "not properly sorted");
241         }
242         return retval;
243 }
244
245 static int fsck_commit(struct commit *commit)
246 {
247         char *buffer = commit->buffer;
248         unsigned char tree_sha1[20], sha1[20];
249
250         if (memcmp(buffer, "tree ", 5))
251                 return objerror(&commit->object, "invalid format - expected 'tree' line");
252         if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
253                 return objerror(&commit->object, "invalid 'tree' line format - bad sha1");
254         buffer += 46;
255         while (!memcmp(buffer, "parent ", 7)) {
256                 if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
257                         return objerror(&commit->object, "invalid 'parent' line format - bad sha1");
258                 buffer += 48;
259         }
260         if (memcmp(buffer, "author ", 7))
261                 return objerror(&commit->object, "invalid format - expected 'author' line");
262         free(commit->buffer);
263         commit->buffer = NULL;
264         if (!commit->tree)
265                 return objerror(&commit->object, "could not load commit's tree %s", tree_sha1);
266         if (!commit->parents && show_root)
267                 printf("root %s\n", sha1_to_hex(commit->object.sha1));
268         if (!commit->date)
269                 printf("bad commit date in %s\n", 
270                        sha1_to_hex(commit->object.sha1));
271         return 0;
272 }
273
274 static int fsck_tag(struct tag *tag)
275 {
276         struct object *tagged = tag->tagged;
277
278         if (!tagged) {
279                 return objerror(&tag->object, "could not load tagged object");
280         }
281         if (!show_tags)
282                 return 0;
283
284         printf("tagged %s %s", typename(tagged->type), sha1_to_hex(tagged->sha1));
285         printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
286         return 0;
287 }
288
289 static int fsck_sha1(unsigned char *sha1)
290 {
291         struct object *obj = parse_object(sha1);
292         if (!obj)
293                 return error("%s: object not found", sha1_to_hex(sha1));
294         if (obj->flags & SEEN)
295                 return 0;
296         obj->flags |= SEEN;
297         if (obj->type == OBJ_BLOB)
298                 return 0;
299         if (obj->type == OBJ_TREE)
300                 return fsck_tree((struct tree *) obj);
301         if (obj->type == OBJ_COMMIT)
302                 return fsck_commit((struct commit *) obj);
303         if (obj->type == OBJ_TAG)
304                 return fsck_tag((struct tag *) obj);
305         /* By now, parse_object() would've returned NULL instead. */
306         return objerror(obj, "unknown type '%d' (internal fsck error)", obj->type);
307 }
308
309 /*
310  * This is the sorting chunk size: make it reasonably
311  * big so that we can sort well..
312  */
313 #define MAX_SHA1_ENTRIES (1024)
314
315 struct sha1_entry {
316         unsigned long ino;
317         unsigned char sha1[20];
318 };
319
320 static struct {
321         unsigned long nr;
322         struct sha1_entry *entry[MAX_SHA1_ENTRIES];
323 } sha1_list;
324
325 static int ino_compare(const void *_a, const void *_b)
326 {
327         const struct sha1_entry *a = _a, *b = _b;
328         unsigned long ino1 = a->ino, ino2 = b->ino;
329         return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
330 }
331
332 static void fsck_sha1_list(void)
333 {
334         int i, nr = sha1_list.nr;
335
336         if (SORT_DIRENT)
337                 qsort(sha1_list.entry, nr,
338                       sizeof(struct sha1_entry *), ino_compare);
339         for (i = 0; i < nr; i++) {
340                 struct sha1_entry *entry = sha1_list.entry[i];
341                 unsigned char *sha1 = entry->sha1;
342
343                 sha1_list.entry[i] = NULL;
344                 fsck_sha1(sha1);
345                 free(entry);
346         }
347         sha1_list.nr = 0;
348 }
349
350 static void add_sha1_list(unsigned char *sha1, unsigned long ino)
351 {
352         struct sha1_entry *entry = xmalloc(sizeof(*entry));
353         int nr;
354
355         entry->ino = ino;
356         hashcpy(entry->sha1, sha1);
357         nr = sha1_list.nr;
358         if (nr == MAX_SHA1_ENTRIES) {
359                 fsck_sha1_list();
360                 nr = 0;
361         }
362         sha1_list.entry[nr] = entry;
363         sha1_list.nr = ++nr;
364 }
365
366 static void fsck_dir(int i, char *path)
367 {
368         DIR *dir = opendir(path);
369         struct dirent *de;
370
371         if (!dir)
372                 return;
373
374         while ((de = readdir(dir)) != NULL) {
375                 char name[100];
376                 unsigned char sha1[20];
377                 int len = strlen(de->d_name);
378
379                 switch (len) {
380                 case 2:
381                         if (de->d_name[1] != '.')
382                                 break;
383                 case 1:
384                         if (de->d_name[0] != '.')
385                                 break;
386                         continue;
387                 case 38:
388                         sprintf(name, "%02x", i);
389                         memcpy(name+2, de->d_name, len+1);
390                         if (get_sha1_hex(name, sha1) < 0)
391                                 break;
392                         add_sha1_list(sha1, DIRENT_SORT_HINT(de));
393                         continue;
394                 }
395                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
396         }
397         closedir(dir);
398 }
399
400 static int default_refs;
401
402 static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1, char *datail, void *cb_data)
403 {
404         struct object *obj;
405
406         if (!is_null_sha1(osha1)) {
407                 obj = lookup_object(osha1);
408                 if (obj) {
409                         obj->used = 1;
410                         mark_reachable(obj, REACHABLE);
411                 }
412         }
413         obj = lookup_object(nsha1);
414         if (obj) {
415                 obj->used = 1;
416                 mark_reachable(obj, REACHABLE);
417         }
418         return 0;
419 }
420
421 static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
422 {
423         struct object *obj;
424
425         obj = lookup_object(sha1);
426         if (!obj) {
427                 if (has_sha1_file(sha1)) {
428                         default_refs++;
429                         return 0; /* it is in a pack */
430                 }
431                 error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
432                 /* We'll continue with the rest despite the error.. */
433                 return 0;
434         }
435         default_refs++;
436         obj->used = 1;
437         mark_reachable(obj, REACHABLE);
438
439         for_each_reflog_ent(refname, fsck_handle_reflog_ent, NULL);
440
441         return 0;
442 }
443
444 static void get_default_heads(void)
445 {
446         for_each_ref(fsck_handle_ref, NULL);
447
448         /*
449          * Not having any default heads isn't really fatal, but
450          * it does mean that "--unreachable" no longer makes any
451          * sense (since in this case everything will obviously
452          * be unreachable by definition.
453          *
454          * Showing dangling objects is valid, though (as those
455          * dangling objects are likely lost heads).
456          *
457          * So we just print a warning about it, and clear the
458          * "show_unreachable" flag.
459          */
460         if (!default_refs) {
461                 error("No default references");
462                 show_unreachable = 0;
463         }
464 }
465
466 static void fsck_object_dir(const char *path)
467 {
468         int i;
469         for (i = 0; i < 256; i++) {
470                 static char dir[4096];
471                 sprintf(dir, "%s/%02x", path, i);
472                 fsck_dir(i, dir);
473         }
474         fsck_sha1_list();
475 }
476
477 static int fsck_head_link(void)
478 {
479         unsigned char sha1[20];
480         int flag;
481         const char *head_points_at = resolve_ref("HEAD", sha1, 1, &flag);
482
483         if (!head_points_at || !(flag & REF_ISSYMREF))
484                 return error("HEAD is not a symbolic ref");
485         if (strncmp(head_points_at, "refs/heads/", 11))
486                 return error("HEAD points to something strange (%s)",
487                              head_points_at);
488         if (is_null_sha1(sha1))
489                 return error("HEAD: not a valid git pointer");
490         return 0;
491 }
492
493 static int fsck_cache_tree(struct cache_tree *it)
494 {
495         int i;
496         int err = 0;
497
498         if (0 <= it->entry_count) {
499                 struct object *obj = parse_object(it->sha1);
500                 if (!obj) {
501                         error("%s: invalid sha1 pointer in cache-tree",
502                               sha1_to_hex(it->sha1));
503                         return 1;
504                 }
505                 mark_reachable(obj, REACHABLE);
506                 obj->used = 1;
507                 if (obj->type != OBJ_TREE)
508                         err |= objerror(obj, "non-tree in cache-tree");
509         }
510         for (i = 0; i < it->subtree_nr; i++)
511                 err |= fsck_cache_tree(it->down[i]->cache_tree);
512         return err;
513 }
514
515 int main(int argc, char **argv)
516 {
517         int i, heads;
518
519         track_object_refs = 1;
520         setup_git_directory();
521
522         for (i = 1; i < argc; i++) {
523                 const char *arg = argv[i];
524
525                 if (!strcmp(arg, "--unreachable")) {
526                         show_unreachable = 1;
527                         continue;
528                 }
529                 if (!strcmp(arg, "--tags")) {
530                         show_tags = 1;
531                         continue;
532                 }
533                 if (!strcmp(arg, "--root")) {
534                         show_root = 1;
535                         continue;
536                 }
537                 if (!strcmp(arg, "--cache")) {
538                         keep_cache_objects = 1;
539                         continue;
540                 }
541                 if (!strcmp(arg, "--full")) {
542                         check_full = 1;
543                         continue;
544                 }
545                 if (!strcmp(arg, "--strict")) {
546                         check_strict = 1;
547                         continue;
548                 }
549                 if (*arg == '-')
550                         usage("git-fsck-objects [--tags] [--root] [[--unreachable] [--cache] [--full] [--strict] <head-sha1>*]");
551         }
552
553         fsck_head_link();
554         fsck_object_dir(get_object_directory());
555         if (check_full) {
556                 struct alternate_object_database *alt;
557                 struct packed_git *p;
558                 prepare_alt_odb();
559                 for (alt = alt_odb_list; alt; alt = alt->next) {
560                         char namebuf[PATH_MAX];
561                         int namelen = alt->name - alt->base;
562                         memcpy(namebuf, alt->base, namelen);
563                         namebuf[namelen - 1] = 0;
564                         fsck_object_dir(namebuf);
565                 }
566                 prepare_packed_git();
567                 for (p = packed_git; p; p = p->next)
568                         /* verify gives error messages itself */
569                         verify_pack(p, 0);
570
571                 for (p = packed_git; p; p = p->next) {
572                         int num = num_packed_objects(p);
573                         for (i = 0; i < num; i++) {
574                                 unsigned char sha1[20];
575                                 nth_packed_object_sha1(p, i, sha1);
576                                 fsck_sha1(sha1);
577                         }
578                 }
579         }
580
581         heads = 0;
582         for (i = 1; i < argc; i++) {
583                 const char *arg = argv[i]; 
584
585                 if (*arg == '-')
586                         continue;
587
588                 if (!get_sha1(arg, head_sha1)) {
589                         struct object *obj = lookup_object(head_sha1);
590
591                         /* Error is printed by lookup_object(). */
592                         if (!obj)
593                                 continue;
594
595                         obj->used = 1;
596                         mark_reachable(obj, REACHABLE);
597                         heads++;
598                         continue;
599                 }
600                 error("invalid parameter: expected sha1, got '%s'", arg);
601         }
602
603         /*
604          * If we've not been given any explicit head information, do the
605          * default ones from .git/refs. We also consider the index file
606          * in this case (ie this implies --cache).
607          */
608         if (!heads) {
609                 get_default_heads();
610                 keep_cache_objects = 1;
611         }
612
613         if (keep_cache_objects) {
614                 int i;
615                 read_cache();
616                 for (i = 0; i < active_nr; i++) {
617                         struct blob *blob = lookup_blob(active_cache[i]->sha1);
618                         struct object *obj;
619                         if (!blob)
620                                 continue;
621                         obj = &blob->object;
622                         obj->used = 1;
623                         mark_reachable(obj, REACHABLE);
624                 }
625                 if (active_cache_tree)
626                         fsck_cache_tree(active_cache_tree);
627         }
628
629         check_connectivity();
630         return 0;
631 }