Fix various dead stores found by the clang static analyzer
[gitweb.git] / builtin-fsck.c
index 2a6e94deaf6b27f27ad7655ebf6072a05b25017c..6436bc224840f11af2f7fa26c61b62c25d78d865 100644 (file)
@@ -8,7 +8,9 @@
 #include "pack.h"
 #include "cache-tree.h"
 #include "tree-walk.h"
+#include "fsck.h"
 #include "parse-options.h"
+#include "dir.h"
 
 #define REACHABLE 0x0001
 #define SEEN      0x0002
@@ -21,6 +23,7 @@ static int check_full;
 static int check_strict;
 static int keep_cache_objects;
 static unsigned char head_sha1[20];
+static const char *head_points_at;
 static int errors_found;
 static int write_lost_and_found;
 static int verbose;
@@ -54,13 +57,96 @@ static int objerror(struct object *obj, const char *err, ...)
        return -1;
 }
 
-static int objwarning(struct object *obj, const char *err, ...)
+static int fsck_error_func(struct object *obj, int type, const char *err, ...)
 {
        va_list params;
        va_start(params, err);
-       objreport(obj, "warning", err, params);
+       objreport(obj, (type == FSCK_WARN) ? "warning" : "error", err, params);
        va_end(params);
-       return -1;
+       return (type == FSCK_WARN) ? 0 : 1;
+}
+
+static struct object_array pending;
+
+static int mark_object(struct object *obj, int type, void *data)
+{
+       struct object *parent = data;
+
+       if (!obj) {
+               printf("broken link from %7s %s\n",
+                          typename(parent->type), sha1_to_hex(parent->sha1));
+               printf("broken link from %7s %s\n",
+                          (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
+               errors_found |= ERROR_REACHABLE;
+               return 1;
+       }
+
+       if (type != OBJ_ANY && obj->type != type)
+               objerror(parent, "wrong object type in link");
+
+       if (obj->flags & REACHABLE)
+               return 0;
+       obj->flags |= REACHABLE;
+       if (!obj->parsed) {
+               if (parent && !has_sha1_file(obj->sha1)) {
+                       printf("broken link from %7s %s\n",
+                                typename(parent->type), sha1_to_hex(parent->sha1));
+                       printf("              to %7s %s\n",
+                                typename(obj->type), sha1_to_hex(obj->sha1));
+                       errors_found |= ERROR_REACHABLE;
+               }
+               return 1;
+       }
+
+       add_object_array(obj, (void *) parent, &pending);
+       return 0;
+}
+
+static void mark_object_reachable(struct object *obj)
+{
+       mark_object(obj, OBJ_ANY, 0);
+}
+
+static int traverse_one_object(struct object *obj, struct object *parent)
+{
+       int result;
+       struct tree *tree = NULL;
+
+       if (obj->type == OBJ_TREE) {
+               obj->parsed = 0;
+               tree = (struct tree *)obj;
+               if (parse_tree(tree) < 0)
+                       return 1; /* error already displayed */
+       }
+       result = fsck_walk(obj, mark_object, obj);
+       if (tree) {
+               free(tree->buffer);
+               tree->buffer = NULL;
+       }
+       return result;
+}
+
+static int traverse_reachable(void)
+{
+       int result = 0;
+       while (pending.nr) {
+               struct object_array_entry *entry;
+               struct object *obj, *parent;
+
+               entry = pending.objects + --pending.nr;
+               obj = entry->item;
+               parent = (struct object *) entry->name;
+               result |= traverse_one_object(obj, parent);
+       }
+       return !!result;
+}
+
+static int mark_used(struct object *obj, int type, void *data)
+{
+       if (!obj)
+               return 1;
+       obj->used = 1;
+       return 0;
 }
 
 /*
@@ -68,39 +154,18 @@ static int objwarning(struct object *obj, const char *err, ...)
  */
 static void check_reachable_object(struct object *obj)
 {
-       const struct object_refs *refs;
-
        /*
         * We obviously want the object to be parsed,
         * except if it was in a pack-file and we didn't
         * do a full fsck
         */
        if (!obj->parsed) {
-               if (has_sha1_pack(obj->sha1, NULL))
+               if (has_sha1_pack(obj->sha1))
                        return; /* it is in pack - forget about it */
                printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
                errors_found |= ERROR_REACHABLE;
                return;
        }
-
-       /*
-        * Check that everything that we try to reference is also good.
-        */
-       refs = lookup_object_refs(obj);
-       if (refs) {
-               unsigned j;
-               for (j = 0; j < refs->count; j++) {
-                       struct object *ref = refs->ref[j];
-                       if (ref->parsed ||
-                           (has_sha1_file(ref->sha1)))
-                               continue;
-                       printf("broken link from %7s %s\n",
-                              typename(obj->type), sha1_to_hex(obj->sha1));
-                       printf("              to %7s %s\n",
-                              typename(ref->type), sha1_to_hex(ref->sha1));
-                       errors_found |= ERROR_REACHABLE;
-               }
-       }
 }
 
 /*
@@ -159,12 +224,16 @@ static void check_unreachable_object(struct object *obj)
                                char *buf = read_sha1_file(obj->sha1,
                                                &type, &size);
                                if (buf) {
-                                       fwrite(buf, size, 1, f);
+                                       if (fwrite(buf, size, 1, f) != 1)
+                                               die("Could not write %s: %s",
+                                                   filename, strerror(errno));
                                        free(buf);
                                }
                        } else
                                fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
-                       fclose(f);
+                       if (fclose(f))
+                               die("Could not finish %s: %s",
+                                   filename, strerror(errno));
                }
                return;
        }
@@ -191,6 +260,9 @@ static void check_connectivity(void)
 {
        int i, max;
 
+       /* Traverse the pending reachable objects */
+       traverse_reachable();
+
        /* Look up all the requirements, warn about missing objects.. */
        max = get_max_object_index();
        if (verbose)
@@ -204,230 +276,56 @@ static void check_connectivity(void)
        }
 }
 
-/*
- * 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)
+static int fsck_sha1(const unsigned char *sha1)
 {
-       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)
+       struct object *obj = parse_object(sha1);
+       if (!obj) {
+               errors_found |= ERROR_OBJECT;
+               return error("%s: object corrupt or missing",
+                            sha1_to_hex(sha1));
+       }
+       if (obj->flags & SEEN)
                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 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;
+       obj->flags |= SEEN;
 
        if (verbose)
-               fprintf(stderr, "Checking tree %s\n",
-                               sha1_to_hex(item->object.sha1));
-
-       init_tree_desc(&desc, item->buffer, item->size);
-
-       o_mode = 0;
-       o_name = NULL;
-       o_sha1 = NULL;
-       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 (!check_strict)
-                               break;
-               default:
-                       has_bad_modes = 1;
-               }
+               fprintf(stderr, "Checking %s %s\n",
+                       typename(obj->type), sha1_to_hex(obj->sha1));
 
-               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;
-                       }
-               }
+       if (fsck_walk(obj, mark_used, 0))
+               objerror(obj, "broken links");
+       if (fsck_object(obj, check_strict, fsck_error_func))
+               return -1;
 
-               o_mode = mode;
-               o_name = name;
-               o_sha1 = sha1;
-       }
-       free(item->buffer);
-       item->buffer = NULL;
+       if (obj->type == OBJ_TREE) {
+               struct tree *item = (struct tree *) obj;
 
-       retval = 0;
-       if (has_full_path) {
-               objwarning(&item->object, "contains full pathnames");
-       }
-       if (has_empty_name) {
-               objwarning(&item->object, "contains empty pathname");
-       }
-       if (has_zero_pad) {
-               objwarning(&item->object, "contains zero-padded file modes");
-       }
-       if (has_bad_modes) {
-               objwarning(&item->object, "contains bad file modes");
-       }
-       if (has_dup_entries) {
-               retval = objerror(&item->object, "contains duplicate file entries");
-       }
-       if (not_properly_sorted) {
-               retval = objerror(&item->object, "not properly sorted");
+               free(item->buffer);
+               item->buffer = NULL;
        }
-       return retval;
-}
 
-static int fsck_commit(struct commit *commit)
-{
-       char *buffer = commit->buffer;
-       unsigned char tree_sha1[20], sha1[20];
+       if (obj->type == OBJ_COMMIT) {
+               struct commit *commit = (struct commit *) obj;
 
-       if (verbose)
-               fprintf(stderr, "Checking commit %s\n",
-                       sha1_to_hex(commit->object.sha1));
-
-       if (memcmp(buffer, "tree ", 5))
-               return objerror(&commit->object, "invalid format - expected 'tree' line");
-       if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
-               return objerror(&commit->object, "invalid 'tree' line format - bad sha1");
-       buffer += 46;
-       while (!memcmp(buffer, "parent ", 7)) {
-               if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
-                       return objerror(&commit->object, "invalid 'parent' line format - bad sha1");
-               buffer += 48;
-       }
-       if (memcmp(buffer, "author ", 7))
-               return objerror(&commit->object, "invalid format - expected 'author' line");
-       free(commit->buffer);
-       commit->buffer = NULL;
-       if (!commit->tree)
-               return objerror(&commit->object, "could not load commit's tree %s", tree_sha1);
-       if (!commit->parents && show_root)
-               printf("root %s\n", sha1_to_hex(commit->object.sha1));
-       if (!commit->date)
-               printf("bad commit date in %s\n",
-                      sha1_to_hex(commit->object.sha1));
-       return 0;
-}
+               free(commit->buffer);
+               commit->buffer = NULL;
 
-static int fsck_tag(struct tag *tag)
-{
-       struct object *tagged = tag->tagged;
+               if (!commit->parents && show_root)
+                       printf("root %s\n", sha1_to_hex(commit->object.sha1));
+       }
 
-       if (verbose)
-               fprintf(stderr, "Checking tag %s\n",
-                       sha1_to_hex(tag->object.sha1));
+       if (obj->type == OBJ_TAG) {
+               struct tag *tag = (struct tag *) obj;
 
-       if (!tagged) {
-               return objerror(&tag->object, "could not load tagged object");
+               if (show_tags && tag->tagged) {
+                       printf("tagged %s %s", typename(tag->tagged->type), sha1_to_hex(tag->tagged->sha1));
+                       printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
+               }
        }
-       if (!show_tags)
-               return 0;
 
-       printf("tagged %s %s", typename(tagged->type), sha1_to_hex(tagged->sha1));
-       printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
        return 0;
 }
 
-static int fsck_sha1(const unsigned char *sha1)
-{
-       struct object *obj = parse_object(sha1);
-       if (!obj) {
-               errors_found |= ERROR_OBJECT;
-               return error("%s: object corrupt or missing",
-                            sha1_to_hex(sha1));
-       }
-       if (obj->flags & SEEN)
-               return 0;
-       obj->flags |= SEEN;
-       if (obj->type == OBJ_BLOB)
-               return 0;
-       if (obj->type == OBJ_TREE)
-               return fsck_tree((struct tree *) obj);
-       if (obj->type == OBJ_COMMIT)
-               return fsck_commit((struct commit *) obj);
-       if (obj->type == OBJ_TAG)
-               return fsck_tag((struct tag *) obj);
-
-       /* By now, parse_object() would've returned NULL instead. */
-       return objerror(obj, "unknown type '%d' (internal fsck error)",
-                       obj->type);
-}
-
 /*
  * This is the sorting chunk size: make it reasonably
  * big so that we can sort well..
@@ -499,24 +397,19 @@ static void fsck_dir(int i, char *path)
        while ((de = readdir(dir)) != NULL) {
                char name[100];
                unsigned char sha1[20];
-               int len = strlen(de->d_name);
 
-               switch (len) {
-               case 2:
-                       if (de->d_name[1] != '.')
-                               break;
-               case 1:
-                       if (de->d_name[0] != '.')
-                               break;
+               if (is_dot_or_dotdot(de->d_name))
                        continue;
-               case 38:
+               if (strlen(de->d_name) == 38) {
                        sprintf(name, "%02x", i);
-                       memcpy(name+2, de->d_name, len+1);
+                       memcpy(name+2, de->d_name, 39);
                        if (get_sha1_hex(name, sha1) < 0)
                                break;
                        add_sha1_list(sha1, DIRENT_SORT_HINT(de));
                        continue;
                }
+               if (!prefixcmp(de->d_name, "tmp_obj_"))
+                       continue;
                fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
        }
        closedir(dir);
@@ -538,13 +431,13 @@ static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
                obj = lookup_object(osha1);
                if (obj) {
                        obj->used = 1;
-                       mark_reachable(obj, REACHABLE);
+                       mark_object_reachable(obj);
                }
        }
        obj = lookup_object(nsha1);
        if (obj) {
                obj->used = 1;
-               mark_reachable(obj, REACHABLE);
+               mark_object_reachable(obj);
        }
        return 0;
 }
@@ -574,13 +467,15 @@ static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int f
                error("%s: not a commit", refname);
        default_refs++;
        obj->used = 1;
-       mark_reachable(obj, REACHABLE);
+       mark_object_reachable(obj);
 
        return 0;
 }
 
 static void get_default_heads(void)
 {
+       if (head_points_at && !is_null_sha1(head_sha1))
+               fsck_handle_ref("HEAD", head_sha1, 0, NULL);
        for_each_ref(fsck_handle_ref, NULL);
        if (include_reflogs)
                for_each_reflog(fsck_handle_reflog, NULL);
@@ -620,14 +515,13 @@ static void fsck_object_dir(const char *path)
 
 static int fsck_head_link(void)
 {
-       unsigned char sha1[20];
        int flag;
        int null_is_error = 0;
-       const char *head_points_at = resolve_ref("HEAD", sha1, 0, &flag);
 
        if (verbose)
                fprintf(stderr, "Checking HEAD link\n");
 
+       head_points_at = resolve_ref("HEAD", head_sha1, 0, &flag);
        if (!head_points_at)
                return error("Invalid HEAD");
        if (!strcmp(head_points_at, "HEAD"))
@@ -636,7 +530,7 @@ static int fsck_head_link(void)
        else if (prefixcmp(head_points_at, "refs/heads/"))
                return error("HEAD points to something strange (%s)",
                             head_points_at);
-       if (is_null_sha1(sha1)) {
+       if (is_null_sha1(head_sha1)) {
                if (null_is_error)
                        return error("HEAD: detached HEAD points at nothing");
                fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
@@ -660,7 +554,7 @@ static int fsck_cache_tree(struct cache_tree *it)
                              sha1_to_hex(it->sha1));
                        return 1;
                }
-               mark_reachable(obj, REACHABLE);
+               mark_object_reachable(obj);
                obj->used = 1;
                if (obj->type != OBJ_TREE)
                        err |= objerror(obj, "non-tree in cache-tree");
@@ -671,7 +565,7 @@ static int fsck_cache_tree(struct cache_tree *it)
 }
 
 static char const * const fsck_usage[] = {
-       "git-fsck [options] [<object>...]",
+       "git fsck [options] [<object>...]",
        NULL
 };
 
@@ -692,8 +586,8 @@ static struct option fsck_opts[] = {
 int cmd_fsck(int argc, const char **argv, const char *prefix)
 {
        int i, heads;
+       struct alternate_object_database *alt;
 
-       track_object_refs = 1;
        errors_found = 0;
 
        argc = parse_options(argc, argv, fsck_opts, fsck_usage, 0);
@@ -704,21 +598,23 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 
        fsck_head_link();
        fsck_object_dir(get_object_directory());
+
+       prepare_alt_odb();
+       for (alt = alt_odb_list; alt; alt = alt->next) {
+               char namebuf[PATH_MAX];
+               int namelen = alt->name - alt->base;
+               memcpy(namebuf, alt->base, namelen);
+               namebuf[namelen - 1] = 0;
+               fsck_object_dir(namebuf);
+       }
+
        if (check_full) {
-               struct alternate_object_database *alt;
                struct packed_git *p;
-               prepare_alt_odb();
-               for (alt = alt_odb_list; alt; alt = alt->next) {
-                       char namebuf[PATH_MAX];
-                       int namelen = alt->name - alt->base;
-                       memcpy(namebuf, alt->base, namelen);
-                       namebuf[namelen - 1] = 0;
-                       fsck_object_dir(namebuf);
-               }
+
                prepare_packed_git();
                for (p = packed_git; p; p = p->next)
                        /* verify gives error messages itself */
-                       verify_pack(p, 0);
+                       verify_pack(p);
 
                for (p = packed_git; p; p = p->next) {
                        uint32_t j, num;
@@ -731,17 +627,18 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
        }
 
        heads = 0;
-       for (i = 1; i < argc; i++) {
+       for (i = 0; i < argc; i++) {
                const char *arg = argv[i];
-               if (!get_sha1(arg, head_sha1)) {
-                       struct object *obj = lookup_object(head_sha1);
+               unsigned char sha1[20];
+               if (!get_sha1(arg, sha1)) {
+                       struct object *obj = lookup_object(sha1);
 
                        /* Error is printed by lookup_object(). */
                        if (!obj)
                                continue;
 
                        obj->used = 1;
-                       mark_reachable(obj, REACHABLE);
+                       mark_object_reachable(obj);
                        heads++;
                        continue;
                }
@@ -765,7 +662,7 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
                        struct blob *blob;
                        struct object *obj;
 
-                       mode = ntohl(active_cache[i]->ce_mode);
+                       mode = active_cache[i]->ce_mode;
                        if (S_ISGITLINK(mode))
                                continue;
                        blob = lookup_blob(active_cache[i]->sha1);
@@ -773,7 +670,7 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
                                continue;
                        obj = &blob->object;
                        obj->used = 1;
-                       mark_reachable(obj, REACHABLE);
+                       mark_object_reachable(obj);
                }
                if (active_cache_tree)
                        fsck_cache_tree(active_cache_tree);