builtin-fsck: move common object checking code to fsck.c
[git/git.git] / fsck.c
diff --git a/fsck.c b/fsck.c
index 98fb41a..0680862 100644 (file)
--- a/fsck.c
+++ b/fsck.c
@@ -89,3 +89,218 @@ int fsck_walk(struct object *obj, fsck_walk_func walk, void *data)
                return -1;
        }
 }
                return -1;
        }
 }
+
+/*
+ * The entries in a tree are ordered in the _path_ order,
+ * which means that a directory entry is ordered by adding
+ * a slash to the end of it.
+ *
+ * So a directory called "a" is ordered _after_ a file
+ * called "a.c", because "a/" sorts after "a.c".
+ */
+#define TREE_UNORDERED (-1)
+#define TREE_HAS_DUPS  (-2)
+
+static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
+{
+       int len1 = strlen(name1);
+       int len2 = strlen(name2);
+       int len = len1 < len2 ? len1 : len2;
+       unsigned char c1, c2;
+       int cmp;
+
+       cmp = memcmp(name1, name2, len);
+       if (cmp < 0)
+               return 0;
+       if (cmp > 0)
+               return TREE_UNORDERED;
+
+       /*
+        * Ok, the first <len> characters are the same.
+        * Now we need to order the next one, but turn
+        * a '\0' into a '/' for a directory entry.
+        */
+       c1 = name1[len];
+       c2 = name2[len];
+       if (!c1 && !c2)
+               /*
+                * git-write-tree used to write out a nonsense tree that has
+                * entries with the same name, one blob and one tree.  Make
+                * sure we do not have duplicate entries.
+                */
+               return TREE_HAS_DUPS;
+       if (!c1 && S_ISDIR(mode1))
+               c1 = '/';
+       if (!c2 && S_ISDIR(mode2))
+               c2 = '/';
+       return c1 < c2 ? 0 : TREE_UNORDERED;
+}
+
+static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
+{
+       int retval;
+       int has_full_path = 0;
+       int has_empty_name = 0;
+       int has_zero_pad = 0;
+       int has_bad_modes = 0;
+       int has_dup_entries = 0;
+       int not_properly_sorted = 0;
+       struct tree_desc desc;
+       unsigned o_mode;
+       const char *o_name;
+       const unsigned char *o_sha1;
+
+       init_tree_desc(&desc, item->buffer, item->size);
+
+       o_mode = 0;
+       o_name = NULL;
+       o_sha1 = NULL;
+       if (!desc.size)
+               return error_func(&item->object, FSCK_ERROR, "empty tree");
+
+       while (desc.size) {
+               unsigned mode;
+               const char *name;
+               const unsigned char *sha1;
+
+               sha1 = tree_entry_extract(&desc, &name, &mode);
+
+               if (strchr(name, '/'))
+                       has_full_path = 1;
+               if (!*name)
+                       has_empty_name = 1;
+               has_zero_pad |= *(char *)desc.buffer == '0';
+               update_tree_entry(&desc);
+
+               switch (mode) {
+               /*
+                * Standard modes..
+                */
+               case S_IFREG | 0755:
+               case S_IFREG | 0644:
+               case S_IFLNK:
+               case S_IFDIR:
+               case S_IFGITLINK:
+                       break;
+               /*
+                * This is nonstandard, but we had a few of these
+                * early on when we honored the full set of mode
+                * bits..
+                */
+               case S_IFREG | 0664:
+                       if (!strict)
+                               break;
+               default:
+                       has_bad_modes = 1;
+               }
+
+               if (o_name) {
+                       switch (verify_ordered(o_mode, o_name, mode, name)) {
+                       case TREE_UNORDERED:
+                               not_properly_sorted = 1;
+                               break;
+                       case TREE_HAS_DUPS:
+                               has_dup_entries = 1;
+                               break;
+                       default:
+                               break;
+                       }
+               }
+
+               o_mode = mode;
+               o_name = name;
+               o_sha1 = sha1;
+       }
+
+       retval = 0;
+       if (has_full_path)
+               retval += error_func(&item->object, FSCK_WARN, "contains full pathnames");
+       if (has_empty_name)
+               retval += error_func(&item->object, FSCK_WARN, "contains empty pathname");
+       if (has_zero_pad)
+               retval += error_func(&item->object, FSCK_WARN, "contains zero-padded file modes");
+       if (has_bad_modes)
+               retval += error_func(&item->object, FSCK_WARN, "contains bad file modes");
+       if (has_dup_entries)
+               retval += error_func(&item->object, FSCK_ERROR, "contains duplicate file entries");
+       if (not_properly_sorted)
+               retval += error_func(&item->object, FSCK_ERROR, "not properly sorted");
+       return retval;
+}
+
+static int fsck_commit(struct commit *commit, fsck_error error_func)
+{
+       char *buffer = commit->buffer;
+       unsigned char tree_sha1[20], sha1[20];
+       struct commit_graft *graft;
+       int parents = 0;
+
+       if (!commit->date)
+               return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line");
+
+       if (memcmp(buffer, "tree ", 5))
+               return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line");
+       if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
+               return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1");
+       buffer += 46;
+       while (!memcmp(buffer, "parent ", 7)) {
+               if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
+                       return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1");
+               buffer += 48;
+               parents++;
+       }
+       graft = lookup_commit_graft(commit->object.sha1);
+       if (graft) {
+               struct commit_list *p = commit->parents;
+               parents = 0;
+               while (p) {
+                       p = p->next;
+                       parents++;
+               }
+               if (graft->nr_parent == -1 && !parents)
+                       ; /* shallow commit */
+               else if (graft->nr_parent != parents)
+                       return error_func(&commit->object, FSCK_ERROR, "graft objects missing");
+       } else {
+               struct commit_list *p = commit->parents;
+               while (p && parents) {
+                       p = p->next;
+                       parents--;
+               }
+               if (p || parents)
+                       return error_func(&commit->object, FSCK_ERROR, "parent objects missing");
+       }
+       if (memcmp(buffer, "author ", 7))
+               return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line");
+       if (!commit->tree)
+               return error_func(&commit->object, FSCK_ERROR, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
+
+       return 0;
+}
+
+static int fsck_tag(struct tag *tag, fsck_error error_func)
+{
+       struct object *tagged = tag->tagged;
+
+       if (!tagged)
+               return error_func(&tag->object, FSCK_ERROR, "could not load tagged object");
+       return 0;
+}
+
+int fsck_object(struct object *obj, int strict, fsck_error error_func)
+{
+       if (!obj)
+               return error_func(obj, FSCK_ERROR, "no valid object to fsck");
+
+       if (obj->type == OBJ_BLOB)
+               return 0;
+       if (obj->type == OBJ_TREE)
+               return fsck_tree((struct tree *) obj, strict, error_func);
+       if (obj->type == OBJ_COMMIT)
+               return fsck_commit((struct commit *) obj, error_func);
+       if (obj->type == OBJ_TAG)
+               return fsck_tag((struct tag *) obj, error_func);
+
+       return error_func(obj, FSCK_ERROR, "unknown type '%d' (internal fsck error)",
+                         obj->type);
+}