First cut at libifying revlist generation

This really just splits things up partially, and creates the
interface to set things up by parsing the command line.

No real code changes so far, although the parsing of filenames is a bit
stricter. In particular, if there is a "--", then we do not accept any
filenames before it, and if there isn't any "--", then we check that _all_
paths listed are valid, not just the first one.

The new argument parsing automatically also gives us "--default" and
"--not" handling as in git-rev-parse.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 370 insertions, 0 deletions

diff --git a/revision.c b/revision.c
new file mode 100644
index 000000000..d61410bc5
--- /dev/null
+++ b/revision.c
@@ -0,0 +1,370 @@
+#include "cache.h"
+#include "tag.h"
+#include "blob.h"
+#include "tree.h"
+#include "commit.h"
+#include "refs.h"
+#include "revision.h"
+
+static char *path_name(struct name_path *path, const char *name)
+{
+	struct name_path *p;
+	char *n, *m;
+	int nlen = strlen(name);
+	int len = nlen + 1;
+
+	for (p = path; p; p = p->up) {
+		if (p->elem_len)
+			len += p->elem_len + 1;
+	}
+	n = xmalloc(len);
+	m = n + len - (nlen + 1);
+	strcpy(m, name);
+	for (p = path; p; p = p->up) {
+		if (p->elem_len) {
+			m -= p->elem_len + 1;
+			memcpy(m, p->elem, p->elem_len);
+			m[p->elem_len] = '/';
+		}
+	}
+	return n;
+}
+
+struct object_list **add_object(struct object *obj,
+				       struct object_list **p,
+				       struct name_path *path,
+				       const char *name)
+{
+	struct object_list *entry = xmalloc(sizeof(*entry));
+	entry->item = obj;
+	entry->next = *p;
+	entry->name = path_name(path, name);
+	*p = entry;
+	return &entry->next;
+}
+
+static void mark_blob_uninteresting(struct blob *blob)
+{
+	if (blob->object.flags & UNINTERESTING)
+		return;
+	blob->object.flags |= UNINTERESTING;
+}
+
+void mark_tree_uninteresting(struct tree *tree)
+{
+	struct object *obj = &tree->object;
+	struct tree_entry_list *entry;
+
+	if (obj->flags & UNINTERESTING)
+		return;
+	obj->flags |= UNINTERESTING;
+	if (!has_sha1_file(obj->sha1))
+		return;
+	if (parse_tree(tree) < 0)
+		die("bad tree %s", sha1_to_hex(obj->sha1));
+	entry = tree->entries;
+	tree->entries = NULL;
+	while (entry) {
+		struct tree_entry_list *next = entry->next;
+		if (entry->directory)
+			mark_tree_uninteresting(entry->item.tree);
+		else
+			mark_blob_uninteresting(entry->item.blob);
+		free(entry);
+		entry = next;
+	}
+}
+
+void mark_parents_uninteresting(struct commit *commit)
+{
+	struct commit_list *parents = commit->parents;
+
+	while (parents) {
+		struct commit *commit = parents->item;
+		commit->object.flags |= UNINTERESTING;
+
+		/*
+		 * Normally we haven't parsed the parent
+		 * yet, so we won't have a parent of a parent
+		 * here. However, it may turn out that we've
+		 * reached this commit some other way (where it
+		 * wasn't uninteresting), in which case we need
+		 * to mark its parents recursively too..
+		 */
+		if (commit->parents)
+			mark_parents_uninteresting(commit);
+
+		/*
+		 * A missing commit is ok iff its parent is marked
+		 * uninteresting.
+		 *
+		 * We just mark such a thing parsed, so that when
+		 * it is popped next time around, we won't be trying
+		 * to parse it and get an error.
+		 */
+		if (!has_sha1_file(commit->object.sha1))
+			commit->object.parsed = 1;
+		parents = parents->next;
+	}
+}
+
+static void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
+{
+	add_object(obj, &revs->pending_objects, NULL, name);
+}
+
+static struct commit *get_commit_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
+{
+	struct object *object;
+
+	object = parse_object(sha1);
+	if (!object)
+		die("bad object %s", name);
+
+	/*
+	 * Tag object? Look what it points to..
+	 */
+	while (object->type == tag_type) {
+		struct tag *tag = (struct tag *) object;
+		object->flags |= flags;
+		if (revs->tag_objects && !(object->flags & UNINTERESTING))
+			add_pending_object(revs, object, tag->tag);
+		object = parse_object(tag->tagged->sha1);
+		if (!object)
+			die("bad object %s", sha1_to_hex(tag->tagged->sha1));
+	}
+
+	/*
+	 * Commit object? Just return it, we'll do all the complex
+	 * reachability crud.
+	 */
+	if (object->type == commit_type) {
+		struct commit *commit = (struct commit *)object;
+		object->flags |= flags;
+		if (parse_commit(commit) < 0)
+			die("unable to parse commit %s", name);
+		if (flags & UNINTERESTING)
+			mark_parents_uninteresting(commit);
+		return commit;
+	}
+
+	/*
+	 * Tree object? Either mark it uniniteresting, or add it
+	 * to the list of objects to look at later..
+	 */
+	if (object->type == tree_type) {
+		struct tree *tree = (struct tree *)object;
+		if (!revs->tree_objects)
+			return NULL;
+		if (flags & UNINTERESTING) {
+			mark_tree_uninteresting(tree);
+			return NULL;
+		}
+		add_pending_object(revs, object, "");
+		return NULL;
+	}
+
+	/*
+	 * Blob object? You know the drill by now..
+	 */
+	if (object->type == blob_type) {
+		struct blob *blob = (struct blob *)object;
+		if (!revs->blob_objects)
+			return NULL;
+		if (flags & UNINTERESTING) {
+			mark_blob_uninteresting(blob);
+			return NULL;
+		}
+		add_pending_object(revs, object, "");
+		return NULL;
+	}
+	die("%s is unknown object", name);
+}
+
+static void add_one_commit(struct commit *commit, struct rev_info *revs)
+{
+	if (!commit || (commit->object.flags & SEEN))
+		return;
+	commit->object.flags |= SEEN;
+	commit_list_insert(commit, &revs->commits);
+}
+
+static int all_flags;
+static struct rev_info *all_revs;
+
+static int handle_one_ref(const char *path, const unsigned char *sha1)
+{
+	struct commit *commit = get_commit_reference(all_revs, path, sha1, all_flags);
+	add_one_commit(commit, all_revs);
+	return 0;
+}
+
+static void handle_all(struct rev_info *revs, unsigned flags)
+{
+	all_revs = revs;
+	all_flags = flags;
+	for_each_ref(handle_one_ref);
+}
+
+/*
+ * Parse revision information, filling in the "rev_info" structure,
+ * and removing the used arguments from the argument list.
+ *
+ * Returns the number of arguments left ("new argc").
+ */
+int setup_revisions(int argc, const char **argv, struct rev_info *revs)
+{
+	int i, flags, seen_dashdash;
+	const char *def = NULL;
+	const char **unrecognized = argv+1;
+	int left = 1;
+
+	memset(revs, 0, sizeof(*revs));
+	revs->lifo = 1;
+	revs->dense = 1;
+	revs->prefix = setup_git_directory();
+	revs->max_age = -1;
+	revs->min_age = -1;
+	revs->max_count = -1;
+
+	/* First, search for "--" */
+	seen_dashdash = 0;
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (strcmp(arg, "--"))
+			continue;
+		argv[i] = NULL;
+		argc = i;
+		revs->paths = get_pathspec(revs->prefix, argv + i + 1);
+		seen_dashdash = 1;
+		break;
+	}
+
+	flags = 0;
+	for (i = 1; i < argc; i++) {
+		struct commit *commit;
+		const char *arg = argv[i];
+		unsigned char sha1[20];
+		char *dotdot;
+		int local_flags;
+
+		if (*arg == '-') {
+			if (!strncmp(arg, "--max-count=", 12)) {
+				revs->max_count = atoi(arg + 12);
+				continue;
+			}
+			if (!strncmp(arg, "--max-age=", 10)) {
+				revs->max_age = atoi(arg + 10);
+				continue;
+			}
+			if (!strncmp(arg, "--min-age=", 10)) {
+				revs->min_age = atoi(arg + 10);
+				continue;
+			}
+			if (!strcmp(arg, "--all")) {
+				handle_all(revs, flags);
+				continue;
+			}
+			if (!strcmp(arg, "--not")) {
+				flags ^= UNINTERESTING;
+				continue;
+			}
+			if (!strcmp(arg, "--default")) {
+				if (++i >= argc)
+					die("bad --default argument");
+				def = argv[i];
+				continue;
+			}
+			if (!strcmp(arg, "--topo-order")) {
+				revs->topo_order = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--date-order")) {
+				revs->lifo = 0;
+				revs->topo_order = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--dense")) {
+				revs->dense = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--sparse")) {
+				revs->dense = 0;
+				continue;
+			}
+			if (!strcmp(arg, "--remove-empty")) {
+				revs->remove_empty_trees = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--objects")) {
+				revs->tag_objects = 1;
+				revs->tree_objects = 1;
+				revs->blob_objects = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--objects-edge")) {
+				revs->tag_objects = 1;
+				revs->tree_objects = 1;
+				revs->blob_objects = 1;
+				revs->edge_hint = 1;
+				continue;
+			}
+			*unrecognized++ = arg;
+			left++;
+			continue;
+		}
+		dotdot = strstr(arg, "..");
+		if (dotdot) {
+			unsigned char from_sha1[20];
+			char *next = dotdot + 2;
+			*dotdot = 0;
+			if (!*next)
+				next = "HEAD";
+			if (!get_sha1(arg, from_sha1) && !get_sha1(next, sha1)) {
+				struct commit *exclude;
+				struct commit *include;
+
+				exclude = get_commit_reference(revs, arg, from_sha1, flags ^ UNINTERESTING);
+				include = get_commit_reference(revs, next, sha1, flags);
+				if (!exclude || !include)
+					die("Invalid revision range %s..%s", arg, next);
+				add_one_commit(exclude, revs);
+				add_one_commit(include, revs);
+				continue;
+			}
+			*dotdot = '.';
+		}
+		local_flags = 0;
+		if (*arg == '^') {
+			local_flags = UNINTERESTING;
+			arg++;
+		}
+		if (get_sha1(arg, sha1) < 0) {
+			struct stat st;
+			int j;
+
+			if (seen_dashdash || local_flags)
+				die("bad revision '%s'", arg);
+
+			/* If we didn't have a "--", all filenames must exist */
+			for (j = i; j < argc; j++) {
+				if (lstat(argv[j], &st) < 0)
+					die("'%s': %s", arg, strerror(errno));
+			}
+			revs->paths = get_pathspec(revs->prefix, argv + i);
+			break;
+		}
+		commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
+		add_one_commit(commit, revs);
+	}
+	if (def && !revs->commits) {
+		unsigned char sha1[20];
+		struct commit *commit;
+		if (get_sha1(def, sha1) < 0)
+			die("bad default revision '%s'", def);
+		commit = get_commit_reference(revs, def, sha1, 0);
+		add_one_commit(commit, revs);
+	}
+	*unrecognized = NULL;
+	return left;
+}