Make fsck and fsck-objects be builtins.

The earlier change df391b192 to rename fsck-objects to fsck broke
fsck-objects.  This should fix it again.

Signed-off-by: Mark Wooding <mdw@distorted.org.uk>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 689 insertions, 0 deletions

diff --git a/builtin-fsck.c b/builtin-fsck.c
new file mode 100644
index 0000000000..fec1cbd784
--- /dev/null
+++ b/builtin-fsck.c
@@ -0,0 +1,689 @@
+#include "cache.h"
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "tag.h"
+#include "refs.h"
+#include "pack.h"
+#include "cache-tree.h"
+#include "tree-walk.h"
+
+#define REACHABLE 0x0001
+#define SEEN      0x0002
+
+static int show_root;
+static int show_tags;
+static int show_unreachable;
+static int check_full;
+static int check_strict;
+static int keep_cache_objects;
+static unsigned char head_sha1[20];
+
+#ifdef NO_D_INO_IN_DIRENT
+#define SORT_DIRENT 0
+#define DIRENT_SORT_HINT(de) 0
+#else
+#define SORT_DIRENT 1
+#define DIRENT_SORT_HINT(de) ((de)->d_ino)
+#endif
+
+static void objreport(struct object *obj, const char *severity,
+                      const char *err, va_list params)
+{
+	fprintf(stderr, "%s in %s %s: ",
+	        severity, typename(obj->type), sha1_to_hex(obj->sha1));
+	vfprintf(stderr, err, params);
+	fputs("\n", stderr);
+}
+
+static int objerror(struct object *obj, const char *err, ...)
+{
+	va_list params;
+	va_start(params, err);
+	objreport(obj, "error", err, params);
+	va_end(params);
+	return -1;
+}
+
+static int objwarning(struct object *obj, const char *err, ...)
+{
+	va_list params;
+	va_start(params, err);
+	objreport(obj, "warning", err, params);
+	va_end(params);
+	return -1;
+}
+
+/*
+ * Check a single reachable object
+ */
+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_file(obj->sha1))
+			return; /* it is in pack - forget about it */
+		printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
+		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));
+		}
+	}
+}
+
+/*
+ * Check a single unreachable object
+ */
+static void check_unreachable_object(struct object *obj)
+{
+	/*
+	 * Missing unreachable object? Ignore it. It's not like
+	 * we miss it (since it can't be reached), nor do we want
+	 * to complain about it being unreachable (since it does
+	 * not exist).
+	 */
+	if (!obj->parsed)
+		return;
+
+	/*
+	 * Unreachable object that exists? Show it if asked to,
+	 * since this is something that is prunable.
+	 */
+	if (show_unreachable) {
+		printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
+		return;
+	}
+
+	/*
+	 * "!used" means that nothing at all points to it, including
+	 * other unreacahble objects. In other words, it's the "tip"
+	 * of some set of unreachable objects, usually a commit that
+	 * got dropped.
+	 *
+	 * Such starting points are more interesting than some random
+	 * set of unreachable objects, so we show them even if the user
+	 * hasn't asked for _all_ unreachable objects. If you have
+	 * deleted a branch by mistake, this is a prime candidate to
+	 * start looking at, for example.
+	 */
+	if (!obj->used) {
+		printf("dangling %s %s\n", typename(obj->type),
+		       sha1_to_hex(obj->sha1));
+		return;
+	}
+
+	/*
+	 * Otherwise? It's there, it's unreachable, and some other unreachable
+	 * object points to it. Ignore it - it's not interesting, and we showed
+	 * all the interesting cases above.
+	 */
+}
+
+static void check_object(struct object *obj)
+{
+	if (obj->flags & REACHABLE)
+		check_reachable_object(obj);
+	else
+		check_unreachable_object(obj);
+}
+
+static void check_connectivity(void)
+{
+	int i, max;
+
+	/* Look up all the requirements, warn about missing objects.. */
+	max = get_max_object_index();
+	for (i = 0; i < max; i++) {
+		struct object *obj = get_indexed_object(i);
+
+		if (obj)
+			check_object(obj);
+	}
+}
+
+/*
+ * 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 retval;
+	int has_full_path = 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;
+
+	desc.buf = item->buffer;
+	desc.size = 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;
+		has_zero_pad |= *(char *)desc.buf == '0';
+		update_tree_entry(&desc);
+
+		switch (mode) {
+		/*
+		 * Standard modes..
+		 */
+		case S_IFREG | 0755:
+		case S_IFREG | 0644:
+		case S_IFLNK:
+		case S_IFDIR:
+			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;
+		}
+
+		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;
+	}
+	free(item->buffer);
+	item->buffer = NULL;
+
+	retval = 0;
+	if (has_full_path) {
+		objwarning(&item->object, "contains full pathnames");
+	}
+	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");
+	}
+	return retval;
+}
+
+static int fsck_commit(struct commit *commit)
+{
+	char *buffer = commit->buffer;
+	unsigned char tree_sha1[20], sha1[20];
+
+	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;
+}
+
+static int fsck_tag(struct tag *tag)
+{
+	struct object *tagged = tag->tagged;
+
+	if (!tagged) {
+		return objerror(&tag->object, "could not load tagged object");
+	}
+	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(unsigned char *sha1)
+{
+	struct object *obj = parse_object(sha1);
+	if (!obj)
+		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..
+ */
+#define MAX_SHA1_ENTRIES (1024)
+
+struct sha1_entry {
+	unsigned long ino;
+	unsigned char sha1[20];
+};
+
+static struct {
+	unsigned long nr;
+	struct sha1_entry *entry[MAX_SHA1_ENTRIES];
+} sha1_list;
+
+static int ino_compare(const void *_a, const void *_b)
+{
+	const struct sha1_entry *a = _a, *b = _b;
+	unsigned long ino1 = a->ino, ino2 = b->ino;
+	return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
+}
+
+static void fsck_sha1_list(void)
+{
+	int i, nr = sha1_list.nr;
+
+	if (SORT_DIRENT)
+		qsort(sha1_list.entry, nr,
+		      sizeof(struct sha1_entry *), ino_compare);
+	for (i = 0; i < nr; i++) {
+		struct sha1_entry *entry = sha1_list.entry[i];
+		unsigned char *sha1 = entry->sha1;
+
+		sha1_list.entry[i] = NULL;
+		fsck_sha1(sha1);
+		free(entry);
+	}
+	sha1_list.nr = 0;
+}
+
+static void add_sha1_list(unsigned char *sha1, unsigned long ino)
+{
+	struct sha1_entry *entry = xmalloc(sizeof(*entry));
+	int nr;
+
+	entry->ino = ino;
+	hashcpy(entry->sha1, sha1);
+	nr = sha1_list.nr;
+	if (nr == MAX_SHA1_ENTRIES) {
+		fsck_sha1_list();
+		nr = 0;
+	}
+	sha1_list.entry[nr] = entry;
+	sha1_list.nr = ++nr;
+}
+
+static void fsck_dir(int i, char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *de;
+
+	if (!dir)
+		return;
+
+	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;
+			continue;
+		case 38:
+			sprintf(name, "%02x", i);
+			memcpy(name+2, de->d_name, len+1);
+			if (get_sha1_hex(name, sha1) < 0)
+				break;
+			add_sha1_list(sha1, DIRENT_SORT_HINT(de));
+			continue;
+		}
+		fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
+	}
+	closedir(dir);
+}
+
+static int default_refs;
+
+static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+		const char *email, unsigned long timestamp, int tz,
+		const char *message, void *cb_data)
+{
+	struct object *obj;
+
+	if (!is_null_sha1(osha1)) {
+		obj = lookup_object(osha1);
+		if (obj) {
+			obj->used = 1;
+			mark_reachable(obj, REACHABLE);
+		}
+	}
+	obj = lookup_object(nsha1);
+	if (obj) {
+		obj->used = 1;
+		mark_reachable(obj, REACHABLE);
+	}
+	return 0;
+}
+
+static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct object *obj;
+
+	obj = lookup_object(sha1);
+	if (!obj) {
+		if (has_sha1_file(sha1)) {
+			default_refs++;
+			return 0; /* it is in a pack */
+		}
+		error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
+		/* We'll continue with the rest despite the error.. */
+		return 0;
+	}
+	default_refs++;
+	obj->used = 1;
+	mark_reachable(obj, REACHABLE);
+
+	for_each_reflog_ent(refname, fsck_handle_reflog_ent, NULL);
+
+	return 0;
+}
+
+static void get_default_heads(void)
+{
+	for_each_ref(fsck_handle_ref, NULL);
+
+	/*
+	 * Not having any default heads isn't really fatal, but
+	 * it does mean that "--unreachable" no longer makes any
+	 * sense (since in this case everything will obviously
+	 * be unreachable by definition.
+	 *
+	 * Showing dangling objects is valid, though (as those
+	 * dangling objects are likely lost heads).
+	 *
+	 * So we just print a warning about it, and clear the
+	 * "show_unreachable" flag.
+	 */
+	if (!default_refs) {
+		error("No default references");
+		show_unreachable = 0;
+	}
+}
+
+static void fsck_object_dir(const char *path)
+{
+	int i;
+	for (i = 0; i < 256; i++) {
+		static char dir[4096];
+		sprintf(dir, "%s/%02x", path, i);
+		fsck_dir(i, dir);
+	}
+	fsck_sha1_list();
+}
+
+static int fsck_head_link(void)
+{
+	unsigned char sha1[20];
+	int flag;
+	const char *head_points_at = resolve_ref("HEAD", sha1, 1, &flag);
+
+	if (!head_points_at || !(flag & REF_ISSYMREF))
+		return error("HEAD is not a symbolic ref");
+	if (strncmp(head_points_at, "refs/heads/", 11))
+		return error("HEAD points to something strange (%s)",
+			     head_points_at);
+	if (is_null_sha1(sha1))
+		return error("HEAD: not a valid git pointer");
+	return 0;
+}
+
+static int fsck_cache_tree(struct cache_tree *it)
+{
+	int i;
+	int err = 0;
+
+	if (0 <= it->entry_count) {
+		struct object *obj = parse_object(it->sha1);
+		if (!obj) {
+			error("%s: invalid sha1 pointer in cache-tree",
+			      sha1_to_hex(it->sha1));
+			return 1;
+		}
+		mark_reachable(obj, REACHABLE);
+		obj->used = 1;
+		if (obj->type != OBJ_TREE)
+			err |= objerror(obj, "non-tree in cache-tree");
+	}
+	for (i = 0; i < it->subtree_nr; i++)
+		err |= fsck_cache_tree(it->down[i]->cache_tree);
+	return err;
+}
+
+int cmd_fsck(int argc, char **argv, const char *prefix)
+{
+	int i, heads;
+
+	track_object_refs = 1;
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+
+		if (!strcmp(arg, "--unreachable")) {
+			show_unreachable = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--tags")) {
+			show_tags = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--root")) {
+			show_root = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--cache")) {
+			keep_cache_objects = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--full")) {
+			check_full = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--strict")) {
+			check_strict = 1;
+			continue;
+		}
+		if (*arg == '-')
+			usage("git-fsck [--tags] [--root] [[--unreachable] [--cache] [--full] [--strict] <head-sha1>*]");
+	}
+
+	fsck_head_link();
+	fsck_object_dir(get_object_directory());
+	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);
+
+		for (p = packed_git; p; p = p->next) {
+			int num = num_packed_objects(p);
+			for (i = 0; i < num; i++) {
+				unsigned char sha1[20];
+				nth_packed_object_sha1(p, i, sha1);
+				fsck_sha1(sha1);
+			}
+		}
+	}
+
+	heads = 0;
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i]; 
+
+		if (*arg == '-')
+			continue;
+
+		if (!get_sha1(arg, head_sha1)) {
+			struct object *obj = lookup_object(head_sha1);
+
+			/* Error is printed by lookup_object(). */
+			if (!obj)
+				continue;
+
+			obj->used = 1;
+			mark_reachable(obj, REACHABLE);
+			heads++;
+			continue;
+		}
+		error("invalid parameter: expected sha1, got '%s'", arg);
+	}
+
+	/*
+	 * If we've not been given any explicit head information, do the
+	 * default ones from .git/refs. We also consider the index file
+	 * in this case (ie this implies --cache).
+	 */
+	if (!heads) {
+		get_default_heads();
+		keep_cache_objects = 1;
+	}
+
+	if (keep_cache_objects) {
+		int i;
+		read_cache();
+		for (i = 0; i < active_nr; i++) {
+			struct blob *blob = lookup_blob(active_cache[i]->sha1);
+			struct object *obj;
+			if (!blob)
+				continue;
+			obj = &blob->object;
+			obj->used = 1;
+			mark_reachable(obj, REACHABLE);
+		}
+		if (active_cache_tree)
+			fsck_cache_tree(active_cache_tree);
+	}
+
+	check_connectivity();
+	return 0;
+}