Adding upstream version 1:2.43.0.upstream/1%2.43.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1274 insertions, 0 deletions

diff --git a/builtin/grep.c b/builtin/grep.c
new file mode 100644
index 0000000..fe78d4c
--- /dev/null
+++ b/builtin/grep.c
@@ -0,0 +1,1274 @@
+/*
+ * Builtin "git grep"
+ *
+ * Copyright (c) 2006 Junio C Hamano
+ */
+#include "builtin.h"
+#include "abspath.h"
+#include "gettext.h"
+#include "hex.h"
+#include "repository.h"
+#include "config.h"
+#include "blob.h"
+#include "tree.h"
+#include "commit.h"
+#include "tag.h"
+#include "tree-walk.h"
+#include "parse-options.h"
+#include "string-list.h"
+#include "run-command.h"
+#include "userdiff.h"
+#include "grep.h"
+#include "quote.h"
+#include "dir.h"
+#include "pathspec.h"
+#include "setup.h"
+#include "submodule.h"
+#include "submodule-config.h"
+#include "object-file.h"
+#include "object-name.h"
+#include "object-store-ll.h"
+#include "packfile.h"
+#include "pager.h"
+#include "path.h"
+#include "read-cache-ll.h"
+#include "write-or-die.h"
+
+static const char *grep_prefix;
+
+static char const * const grep_usage[] = {
+	N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
+	NULL
+};
+
+static int recurse_submodules;
+
+static int num_threads;
+
+static pthread_t *threads;
+
+/* We use one producer thread and THREADS consumer
+ * threads. The producer adds struct work_items to 'todo' and the
+ * consumers pick work items from the same array.
+ */
+struct work_item {
+	struct grep_source source;
+	char done;
+	struct strbuf out;
+};
+
+/* In the range [todo_done, todo_start) in 'todo' we have work_items
+ * that have been or are processed by a consumer thread. We haven't
+ * written the result for these to stdout yet.
+ *
+ * The work_items in [todo_start, todo_end) are waiting to be picked
+ * up by a consumer thread.
+ *
+ * The ranges are modulo TODO_SIZE.
+ */
+#define TODO_SIZE 128
+static struct work_item todo[TODO_SIZE];
+static int todo_start;
+static int todo_end;
+static int todo_done;
+
+/* Has all work items been added? */
+static int all_work_added;
+
+static struct repository **repos_to_free;
+static size_t repos_to_free_nr, repos_to_free_alloc;
+
+/* This lock protects all the variables above. */
+static pthread_mutex_t grep_mutex;
+
+static inline void grep_lock(void)
+{
+	pthread_mutex_lock(&grep_mutex);
+}
+
+static inline void grep_unlock(void)
+{
+	pthread_mutex_unlock(&grep_mutex);
+}
+
+/* Signalled when a new work_item is added to todo. */
+static pthread_cond_t cond_add;
+
+/* Signalled when the result from one work_item is written to
+ * stdout.
+ */
+static pthread_cond_t cond_write;
+
+/* Signalled when we are finished with everything. */
+static pthread_cond_t cond_result;
+
+static int skip_first_line;
+
+static void add_work(struct grep_opt *opt, struct grep_source *gs)
+{
+	if (opt->binary != GREP_BINARY_TEXT)
+		grep_source_load_driver(gs, opt->repo->index);
+
+	grep_lock();
+
+	while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
+		pthread_cond_wait(&cond_write, &grep_mutex);
+	}
+
+	todo[todo_end].source = *gs;
+	todo[todo_end].done = 0;
+	strbuf_reset(&todo[todo_end].out);
+	todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
+
+	pthread_cond_signal(&cond_add);
+	grep_unlock();
+}
+
+static struct work_item *get_work(void)
+{
+	struct work_item *ret;
+
+	grep_lock();
+	while (todo_start == todo_end && !all_work_added) {
+		pthread_cond_wait(&cond_add, &grep_mutex);
+	}
+
+	if (todo_start == todo_end && all_work_added) {
+		ret = NULL;
+	} else {
+		ret = &todo[todo_start];
+		todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
+	}
+	grep_unlock();
+	return ret;
+}
+
+static void work_done(struct work_item *w)
+{
+	int old_done;
+
+	grep_lock();
+	w->done = 1;
+	old_done = todo_done;
+	for(; todo[todo_done].done && todo_done != todo_start;
+	    todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
+		w = &todo[todo_done];
+		if (w->out.len) {
+			const char *p = w->out.buf;
+			size_t len = w->out.len;
+
+			/* Skip the leading hunk mark of the first file. */
+			if (skip_first_line) {
+				while (len) {
+					len--;
+					if (*p++ == '\n')
+						break;
+				}
+				skip_first_line = 0;
+			}
+
+			write_or_die(1, p, len);
+		}
+		grep_source_clear(&w->source);
+	}
+
+	if (old_done != todo_done)
+		pthread_cond_signal(&cond_write);
+
+	if (all_work_added && todo_done == todo_end)
+		pthread_cond_signal(&cond_result);
+
+	grep_unlock();
+}
+
+static void free_repos(void)
+{
+	int i;
+
+	for (i = 0; i < repos_to_free_nr; i++) {
+		repo_clear(repos_to_free[i]);
+		free(repos_to_free[i]);
+	}
+	FREE_AND_NULL(repos_to_free);
+	repos_to_free_nr = 0;
+	repos_to_free_alloc = 0;
+}
+
+static void *run(void *arg)
+{
+	int hit = 0;
+	struct grep_opt *opt = arg;
+
+	while (1) {
+		struct work_item *w = get_work();
+		if (!w)
+			break;
+
+		opt->output_priv = w;
+		hit |= grep_source(opt, &w->source);
+		grep_source_clear_data(&w->source);
+		work_done(w);
+	}
+	free_grep_patterns(opt);
+	free(opt);
+
+	return (void*) (intptr_t) hit;
+}
+
+static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
+{
+	struct work_item *w = opt->output_priv;
+	strbuf_add(&w->out, buf, size);
+}
+
+static void start_threads(struct grep_opt *opt)
+{
+	int i;
+
+	pthread_mutex_init(&grep_mutex, NULL);
+	pthread_mutex_init(&grep_attr_mutex, NULL);
+	pthread_cond_init(&cond_add, NULL);
+	pthread_cond_init(&cond_write, NULL);
+	pthread_cond_init(&cond_result, NULL);
+	grep_use_locks = 1;
+	enable_obj_read_lock();
+
+	for (i = 0; i < ARRAY_SIZE(todo); i++) {
+		strbuf_init(&todo[i].out, 0);
+	}
+
+	CALLOC_ARRAY(threads, num_threads);
+	for (i = 0; i < num_threads; i++) {
+		int err;
+		struct grep_opt *o = grep_opt_dup(opt);
+		o->output = strbuf_out;
+		compile_grep_patterns(o);
+		err = pthread_create(&threads[i], NULL, run, o);
+
+		if (err)
+			die(_("grep: failed to create thread: %s"),
+			    strerror(err));
+	}
+}
+
+static int wait_all(void)
+{
+	int hit = 0;
+	int i;
+
+	if (!HAVE_THREADS)
+		BUG("Never call this function unless you have started threads");
+
+	grep_lock();
+	all_work_added = 1;
+
+	/* Wait until all work is done. */
+	while (todo_done != todo_end)
+		pthread_cond_wait(&cond_result, &grep_mutex);
+
+	/* Wake up all the consumer threads so they can see that there
+	 * is no more work to do.
+	 */
+	pthread_cond_broadcast(&cond_add);
+	grep_unlock();
+
+	for (i = 0; i < num_threads; i++) {
+		void *h;
+		pthread_join(threads[i], &h);
+		hit |= (int) (intptr_t) h;
+	}
+
+	free(threads);
+
+	pthread_mutex_destroy(&grep_mutex);
+	pthread_mutex_destroy(&grep_attr_mutex);
+	pthread_cond_destroy(&cond_add);
+	pthread_cond_destroy(&cond_write);
+	pthread_cond_destroy(&cond_result);
+	grep_use_locks = 0;
+	disable_obj_read_lock();
+
+	return hit;
+}
+
+static int grep_cmd_config(const char *var, const char *value,
+			   const struct config_context *ctx, void *cb)
+{
+	int st = grep_config(var, value, ctx, cb);
+
+	if (git_color_config(var, value, cb) < 0)
+		st = -1;
+	else if (git_default_config(var, value, ctx, cb) < 0)
+		st = -1;
+
+	if (!strcmp(var, "grep.threads")) {
+		num_threads = git_config_int(var, value, ctx->kvi);
+		if (num_threads < 0)
+			die(_("invalid number of threads specified (%d) for %s"),
+			    num_threads, var);
+		else if (!HAVE_THREADS && num_threads > 1) {
+			/*
+			 * TRANSLATORS: %s is the configuration
+			 * variable for tweaking threads, currently
+			 * grep.threads
+			 */
+			warning(_("no threads support, ignoring %s"), var);
+			num_threads = 1;
+		}
+	}
+
+	if (!strcmp(var, "submodule.recurse"))
+		recurse_submodules = git_config_bool(var, value);
+
+	return st;
+}
+
+static void grep_source_name(struct grep_opt *opt, const char *filename,
+			     int tree_name_len, struct strbuf *out)
+{
+	strbuf_reset(out);
+
+	if (opt->null_following_name) {
+		if (opt->relative && grep_prefix) {
+			struct strbuf rel_buf = STRBUF_INIT;
+			const char *rel_name =
+				relative_path(filename + tree_name_len,
+					      grep_prefix, &rel_buf);
+
+			if (tree_name_len)
+				strbuf_add(out, filename, tree_name_len);
+
+			strbuf_addstr(out, rel_name);
+			strbuf_release(&rel_buf);
+		} else {
+			strbuf_addstr(out, filename);
+		}
+		return;
+	}
+
+	if (opt->relative && grep_prefix)
+		quote_path(filename + tree_name_len, grep_prefix, out, 0);
+	else
+		quote_c_style(filename + tree_name_len, out, NULL, 0);
+
+	if (tree_name_len)
+		strbuf_insert(out, 0, filename, tree_name_len);
+}
+
+static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
+		     const char *filename, int tree_name_len,
+		     const char *path)
+{
+	struct strbuf pathbuf = STRBUF_INIT;
+	struct grep_source gs;
+
+	grep_source_name(opt, filename, tree_name_len, &pathbuf);
+	grep_source_init_oid(&gs, pathbuf.buf, path, oid, opt->repo);
+	strbuf_release(&pathbuf);
+
+	if (num_threads > 1) {
+		/*
+		 * add_work() copies gs and thus assumes ownership of
+		 * its fields, so do not call grep_source_clear()
+		 */
+		add_work(opt, &gs);
+		return 0;
+	} else {
+		int hit;
+
+		hit = grep_source(opt, &gs);
+
+		grep_source_clear(&gs);
+		return hit;
+	}
+}
+
+static int grep_file(struct grep_opt *opt, const char *filename)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct grep_source gs;
+
+	grep_source_name(opt, filename, 0, &buf);
+	grep_source_init_file(&gs, buf.buf, filename);
+	strbuf_release(&buf);
+
+	if (num_threads > 1) {
+		/*
+		 * add_work() copies gs and thus assumes ownership of
+		 * its fields, so do not call grep_source_clear()
+		 */
+		add_work(opt, &gs);
+		return 0;
+	} else {
+		int hit;
+
+		hit = grep_source(opt, &gs);
+
+		grep_source_clear(&gs);
+		return hit;
+	}
+}
+
+static void append_path(struct grep_opt *opt, const void *data, size_t len)
+{
+	struct string_list *path_list = opt->output_priv;
+
+	if (len == 1 && *(const char *)data == '\0')
+		return;
+	string_list_append_nodup(path_list, xstrndup(data, len));
+}
+
+static void run_pager(struct grep_opt *opt, const char *prefix)
+{
+	struct string_list *path_list = opt->output_priv;
+	struct child_process child = CHILD_PROCESS_INIT;
+	int i, status;
+
+	for (i = 0; i < path_list->nr; i++)
+		strvec_push(&child.args, path_list->items[i].string);
+	child.dir = prefix;
+	child.use_shell = 1;
+
+	status = run_command(&child);
+	if (status)
+		exit(status);
+}
+
+static int grep_cache(struct grep_opt *opt,
+		      const struct pathspec *pathspec, int cached);
+static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
+		     struct tree_desc *tree, struct strbuf *base, int tn_len,
+		     int check_attr);
+
+static int grep_submodule(struct grep_opt *opt,
+			  const struct pathspec *pathspec,
+			  const struct object_id *oid,
+			  const char *filename, const char *path, int cached)
+{
+	struct repository *subrepo;
+	struct repository *superproject = opt->repo;
+	struct grep_opt subopt;
+	int hit = 0;
+
+	if (!is_submodule_active(superproject, path))
+		return 0;
+
+	subrepo = xmalloc(sizeof(*subrepo));
+	if (repo_submodule_init(subrepo, superproject, path, null_oid())) {
+		free(subrepo);
+		return 0;
+	}
+	ALLOC_GROW(repos_to_free, repos_to_free_nr + 1, repos_to_free_alloc);
+	repos_to_free[repos_to_free_nr++] = subrepo;
+
+	/*
+	 * NEEDSWORK: repo_read_gitmodules() might call
+	 * add_to_alternates_memory() via config_from_gitmodules(). This
+	 * operation causes a race condition with concurrent object readings
+	 * performed by the worker threads. That's why we need obj_read_lock()
+	 * here. It should be removed once it's no longer necessary to add the
+	 * subrepo's odbs to the in-memory alternates list.
+	 */
+	obj_read_lock();
+
+	/*
+	 * NEEDSWORK: when reading a submodule, the sparsity settings in the
+	 * superproject are incorrectly forgotten or misused. For example:
+	 *
+	 * 1. "command_requires_full_index"
+	 * 	When this setting is turned on for `grep`, only the superproject
+	 *	knows it. All the submodules are read with their own configs
+	 *	and get prepare_repo_settings()'d. Therefore, these submodules
+	 *	"forget" the sparse-index feature switch. As a result, the index
+	 *	of these submodules are expanded unexpectedly.
+	 *
+	 * 2. "core_apply_sparse_checkout"
+	 *	When running `grep` in the superproject, this setting is
+	 *	populated using the superproject's configs. However, once
+	 *	initialized, this config is globally accessible and is read by
+	 *	prepare_repo_settings() for the submodules. For instance, if a
+	 *	submodule is using a sparse-checkout, however, the superproject
+	 *	is not, the result is that the config from the superproject will
+	 *	dictate the behavior for the submodule, making it "forget" its
+	 *	sparse-checkout state.
+	 *
+	 * 3. "core_sparse_checkout_cone"
+	 *	ditto.
+	 *
+	 * Note that this list is not exhaustive.
+	 */
+	repo_read_gitmodules(subrepo, 0);
+
+	/*
+	 * All code paths tested by test code no longer need submodule ODBs to
+	 * be added as alternates, but add it to the list just in case.
+	 * Submodule ODBs added through add_submodule_odb_by_path() will be
+	 * lazily registered as alternates when needed (and except in an
+	 * unexpected code interaction, it won't be needed).
+	 */
+	add_submodule_odb_by_path(subrepo->objects->odb->path);
+	obj_read_unlock();
+
+	memcpy(&subopt, opt, sizeof(subopt));
+	subopt.repo = subrepo;
+
+	if (oid) {
+		enum object_type object_type;
+		struct tree_desc tree;
+		void *data;
+		unsigned long size;
+		struct strbuf base = STRBUF_INIT;
+
+		obj_read_lock();
+		object_type = oid_object_info(subrepo, oid, NULL);
+		obj_read_unlock();
+		data = read_object_with_reference(subrepo,
+						  oid, OBJ_TREE,
+						  &size, NULL);
+		if (!data)
+			die(_("unable to read tree (%s)"), oid_to_hex(oid));
+
+		strbuf_addstr(&base, filename);
+		strbuf_addch(&base, '/');
+
+		init_tree_desc(&tree, data, size);
+		hit = grep_tree(&subopt, pathspec, &tree, &base, base.len,
+				object_type == OBJ_COMMIT);
+		strbuf_release(&base);
+		free(data);
+	} else {
+		hit = grep_cache(&subopt, pathspec, cached);
+	}
+
+	return hit;
+}
+
+static int grep_cache(struct grep_opt *opt,
+		      const struct pathspec *pathspec, int cached)
+{
+	struct repository *repo = opt->repo;
+	int hit = 0;
+	int nr;
+	struct strbuf name = STRBUF_INIT;
+	int name_base_len = 0;
+	if (repo->submodule_prefix) {
+		name_base_len = strlen(repo->submodule_prefix);
+		strbuf_addstr(&name, repo->submodule_prefix);
+	}
+
+	if (repo_read_index(repo) < 0)
+		die(_("index file corrupt"));
+
+	for (nr = 0; nr < repo->index->cache_nr; nr++) {
+		const struct cache_entry *ce = repo->index->cache[nr];
+
+		if (!cached && ce_skip_worktree(ce))
+			continue;
+
+		strbuf_setlen(&name, name_base_len);
+		strbuf_addstr(&name, ce->name);
+		if (S_ISSPARSEDIR(ce->ce_mode)) {
+			enum object_type type;
+			struct tree_desc tree;
+			void *data;
+			unsigned long size;
+
+			data = repo_read_object_file(the_repository, &ce->oid,
+						     &type, &size);
+			init_tree_desc(&tree, data, size);
+
+			hit |= grep_tree(opt, pathspec, &tree, &name, 0, 0);
+			strbuf_setlen(&name, name_base_len);
+			strbuf_addstr(&name, ce->name);
+			free(data);
+		} else if (S_ISREG(ce->ce_mode) &&
+		    match_pathspec(repo->index, pathspec, name.buf, name.len, 0, NULL,
+				   S_ISDIR(ce->ce_mode) ||
+				   S_ISGITLINK(ce->ce_mode))) {
+			/*
+			 * If CE_VALID is on, we assume worktree file and its
+			 * cache entry are identical, even if worktree file has
+			 * been modified, so use cache version instead
+			 */
+			if (cached || (ce->ce_flags & CE_VALID)) {
+				if (ce_stage(ce) || ce_intent_to_add(ce))
+					continue;
+				hit |= grep_oid(opt, &ce->oid, name.buf,
+						 0, name.buf);
+			} else {
+				hit |= grep_file(opt, name.buf);
+			}
+		} else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
+			   submodule_path_match(repo->index, pathspec, name.buf, NULL)) {
+			hit |= grep_submodule(opt, pathspec, NULL, ce->name,
+					      ce->name, cached);
+		} else {
+			continue;
+		}
+
+		if (ce_stage(ce)) {
+			do {
+				nr++;
+			} while (nr < repo->index->cache_nr &&
+				 !strcmp(ce->name, repo->index->cache[nr]->name));
+			nr--; /* compensate for loop control */
+		}
+		if (hit && opt->status_only)
+			break;
+	}
+
+	strbuf_release(&name);
+	return hit;
+}
+
+static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
+		     struct tree_desc *tree, struct strbuf *base, int tn_len,
+		     int check_attr)
+{
+	struct repository *repo = opt->repo;
+	int hit = 0;
+	enum interesting match = entry_not_interesting;
+	struct name_entry entry;
+	int old_baselen = base->len;
+	struct strbuf name = STRBUF_INIT;
+	int name_base_len = 0;
+	if (repo->submodule_prefix) {
+		strbuf_addstr(&name, repo->submodule_prefix);
+		name_base_len = name.len;
+	}
+
+	while (tree_entry(tree, &entry)) {
+		int te_len = tree_entry_len(&entry);
+
+		if (match != all_entries_interesting) {
+			strbuf_addstr(&name, base->buf + tn_len);
+			match = tree_entry_interesting(repo->index,
+						       &entry, &name,
+						       pathspec);
+			strbuf_setlen(&name, name_base_len);
+
+			if (match == all_entries_not_interesting)
+				break;
+			if (match == entry_not_interesting)
+				continue;
+		}
+
+		strbuf_add(base, entry.path, te_len);
+
+		if (S_ISREG(entry.mode)) {
+			hit |= grep_oid(opt, &entry.oid, base->buf, tn_len,
+					 check_attr ? base->buf + tn_len : NULL);
+		} else if (S_ISDIR(entry.mode)) {
+			enum object_type type;
+			struct tree_desc sub;
+			void *data;
+			unsigned long size;
+
+			data = repo_read_object_file(the_repository,
+						     &entry.oid, &type, &size);
+			if (!data)
+				die(_("unable to read tree (%s)"),
+				    oid_to_hex(&entry.oid));
+
+			strbuf_addch(base, '/');
+			init_tree_desc(&sub, data, size);
+			hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
+					 check_attr);
+			free(data);
+		} else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
+			hit |= grep_submodule(opt, pathspec, &entry.oid,
+					      base->buf, base->buf + tn_len,
+					      1); /* ignored */
+		}
+
+		strbuf_setlen(base, old_baselen);
+
+		if (hit && opt->status_only)
+			break;
+	}
+
+	strbuf_release(&name);
+	return hit;
+}
+
+static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
+		       struct object *obj, const char *name, const char *path)
+{
+	if (obj->type == OBJ_BLOB)
+		return grep_oid(opt, &obj->oid, name, 0, path);
+	if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
+		struct tree_desc tree;
+		void *data;
+		unsigned long size;
+		struct strbuf base;
+		int hit, len;
+
+		data = read_object_with_reference(opt->repo,
+						  &obj->oid, OBJ_TREE,
+						  &size, NULL);
+		if (!data)
+			die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
+
+		len = name ? strlen(name) : 0;
+		strbuf_init(&base, PATH_MAX + len + 1);
+		if (len) {
+			strbuf_add(&base, name, len);
+			strbuf_addch(&base, ':');
+		}
+		init_tree_desc(&tree, data, size);
+		hit = grep_tree(opt, pathspec, &tree, &base, base.len,
+				obj->type == OBJ_COMMIT);
+		strbuf_release(&base);
+		free(data);
+		return hit;
+	}
+	die(_("unable to grep from object of type %s"), type_name(obj->type));
+}
+
+static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
+			const struct object_array *list)
+{
+	unsigned int i;
+	int hit = 0;
+	const unsigned int nr = list->nr;
+
+	for (i = 0; i < nr; i++) {
+		struct object *real_obj;
+
+		obj_read_lock();
+		real_obj = deref_tag(opt->repo, list->objects[i].item,
+				     NULL, 0);
+		obj_read_unlock();
+
+		if (!real_obj) {
+			char hex[GIT_MAX_HEXSZ + 1];
+			const char *name = list->objects[i].name;
+
+			if (!name) {
+				oid_to_hex_r(hex, &list->objects[i].item->oid);
+				name = hex;
+			}
+			die(_("invalid object '%s' given."), name);
+		}
+
+		/* load the gitmodules file for this rev */
+		if (recurse_submodules) {
+			submodule_free(opt->repo);
+			obj_read_lock();
+			gitmodules_config_oid(&real_obj->oid);
+			obj_read_unlock();
+		}
+		if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
+				list->objects[i].path)) {
+			hit = 1;
+			if (opt->status_only)
+				break;
+		}
+	}
+	return hit;
+}
+
+static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
+			  int exc_std, int use_index)
+{
+	struct dir_struct dir = DIR_INIT;
+	int i, hit = 0;
+
+	if (!use_index)
+		dir.flags |= DIR_NO_GITLINKS;
+	if (exc_std)
+		setup_standard_excludes(&dir);
+
+	fill_directory(&dir, opt->repo->index, pathspec);
+	for (i = 0; i < dir.nr; i++) {
+		hit |= grep_file(opt, dir.entries[i]->name);
+		if (hit && opt->status_only)
+			break;
+	}
+	dir_clear(&dir);
+	return hit;
+}
+
+static int context_callback(const struct option *opt, const char *arg,
+			    int unset)
+{
+	struct grep_opt *grep_opt = opt->value;
+	int value;
+	const char *endp;
+
+	if (unset) {
+		grep_opt->pre_context = grep_opt->post_context = 0;
+		return 0;
+	}
+	value = strtol(arg, (char **)&endp, 10);
+	if (*endp) {
+		return error(_("switch `%c' expects a numerical value"),
+			     opt->short_name);
+	}
+	grep_opt->pre_context = grep_opt->post_context = value;
+	return 0;
+}
+
+static int file_callback(const struct option *opt, const char *arg, int unset)
+{
+	struct grep_opt *grep_opt = opt->value;
+	int from_stdin;
+	const char *filename = arg;
+	FILE *patterns;
+	int lno = 0;
+	struct strbuf sb = STRBUF_INIT;
+
+	BUG_ON_OPT_NEG(unset);
+
+	if (!*filename)
+		; /* leave it as-is */
+	else
+		filename = prefix_filename_except_for_dash(grep_prefix, filename);
+
+	from_stdin = !strcmp(filename, "-");
+	patterns = from_stdin ? stdin : fopen(filename, "r");
+	if (!patterns)
+		die_errno(_("cannot open '%s'"), arg);
+	while (strbuf_getline(&sb, patterns) == 0) {
+		/* ignore empty line like grep does */
+		if (sb.len == 0)
+			continue;
+
+		append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
+				GREP_PATTERN);
+	}
+	if (!from_stdin)
+		fclose(patterns);
+	strbuf_release(&sb);
+	if (filename != arg)
+		free((void *)filename);
+	return 0;
+}
+
+static int not_callback(const struct option *opt, const char *arg, int unset)
+{
+	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+	append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
+	return 0;
+}
+
+static int and_callback(const struct option *opt, const char *arg, int unset)
+{
+	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+	append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
+	return 0;
+}
+
+static int open_callback(const struct option *opt, const char *arg, int unset)
+{
+	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+	append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
+	return 0;
+}
+
+static int close_callback(const struct option *opt, const char *arg, int unset)
+{
+	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+	append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
+	return 0;
+}
+
+static int pattern_callback(const struct option *opt, const char *arg,
+			    int unset)
+{
+	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
+	append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
+	return 0;
+}
+
+int cmd_grep(int argc, const char **argv, const char *prefix)
+{
+	int hit = 0;
+	int cached = 0, untracked = 0, opt_exclude = -1;
+	int seen_dashdash = 0;
+	int external_grep_allowed__ignored;
+	const char *show_in_pager = NULL, *default_pager = "dummy";
+	struct grep_opt opt;
+	struct object_array list = OBJECT_ARRAY_INIT;
+	struct pathspec pathspec;
+	struct string_list path_list = STRING_LIST_INIT_DUP;
+	int i;
+	int dummy;
+	int use_index = 1;
+	int allow_revs;
+
+	struct option options[] = {
+		OPT_BOOL(0, "cached", &cached,
+			N_("search in index instead of in the work tree")),
+		OPT_NEGBIT(0, "no-index", &use_index,
+			 N_("find in contents not managed by git"), 1),
+		OPT_BOOL(0, "untracked", &untracked,
+			N_("search in both tracked and untracked files")),
+		OPT_SET_INT(0, "exclude-standard", &opt_exclude,
+			    N_("ignore files specified via '.gitignore'"), 1),
+		OPT_BOOL(0, "recurse-submodules", &recurse_submodules,
+			 N_("recursively search in each submodule")),
+		OPT_GROUP(""),
+		OPT_BOOL('v', "invert-match", &opt.invert,
+			N_("show non-matching lines")),
+		OPT_BOOL('i', "ignore-case", &opt.ignore_case,
+			N_("case insensitive matching")),
+		OPT_BOOL('w', "word-regexp", &opt.word_regexp,
+			N_("match patterns only at word boundaries")),
+		OPT_SET_INT('a', "text", &opt.binary,
+			N_("process binary files as text"), GREP_BINARY_TEXT),
+		OPT_SET_INT('I', NULL, &opt.binary,
+			N_("don't match patterns in binary files"),
+			GREP_BINARY_NOMATCH),
+		OPT_BOOL(0, "textconv", &opt.allow_textconv,
+			 N_("process binary files with textconv filters")),
+		OPT_SET_INT('r', "recursive", &opt.max_depth,
+			    N_("search in subdirectories (default)"), -1),
+		OPT_INTEGER_F(0, "max-depth", &opt.max_depth,
+			N_("descend at most <n> levels"), PARSE_OPT_NONEG),
+		OPT_GROUP(""),
+		OPT_SET_INT('E', "extended-regexp", &opt.pattern_type_option,
+			    N_("use extended POSIX regular expressions"),
+			    GREP_PATTERN_TYPE_ERE),
+		OPT_SET_INT('G', "basic-regexp", &opt.pattern_type_option,
+			    N_("use basic POSIX regular expressions (default)"),
+			    GREP_PATTERN_TYPE_BRE),
+		OPT_SET_INT('F', "fixed-strings", &opt.pattern_type_option,
+			    N_("interpret patterns as fixed strings"),
+			    GREP_PATTERN_TYPE_FIXED),
+		OPT_SET_INT('P', "perl-regexp", &opt.pattern_type_option,
+			    N_("use Perl-compatible regular expressions"),
+			    GREP_PATTERN_TYPE_PCRE),
+		OPT_GROUP(""),
+		OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
+		OPT_BOOL(0, "column", &opt.columnnum, N_("show column number of first match")),
+		OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
+		OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
+		OPT_NEGBIT(0, "full-name", &opt.relative,
+			N_("show filenames relative to top directory"), 1),
+		OPT_BOOL('l', "files-with-matches", &opt.name_only,
+			N_("show only filenames instead of matching lines")),
+		OPT_BOOL(0, "name-only", &opt.name_only,
+			N_("synonym for --files-with-matches")),
+		OPT_BOOL('L', "files-without-match",
+			&opt.unmatch_name_only,
+			N_("show only the names of files without match")),
+		OPT_BOOL_F('z', "null", &opt.null_following_name,
+			   N_("print NUL after filenames"),
+			   PARSE_OPT_NOCOMPLETE),
+		OPT_BOOL('o', "only-matching", &opt.only_matching,
+			N_("show only matching parts of a line")),
+		OPT_BOOL('c', "count", &opt.count,
+			N_("show the number of matches instead of matching lines")),
+		OPT__COLOR(&opt.color, N_("highlight matches")),
+		OPT_BOOL(0, "break", &opt.file_break,
+			N_("print empty line between matches from different files")),
+		OPT_BOOL(0, "heading", &opt.heading,
+			N_("show filename only once above matches from same file")),
+		OPT_GROUP(""),
+		OPT_CALLBACK('C', "context", &opt, N_("n"),
+			N_("show <n> context lines before and after matches"),
+			context_callback),
+		OPT_INTEGER('B', "before-context", &opt.pre_context,
+			N_("show <n> context lines before matches")),
+		OPT_INTEGER('A', "after-context", &opt.post_context,
+			N_("show <n> context lines after matches")),
+		OPT_INTEGER(0, "threads", &num_threads,
+			N_("use <n> worker threads")),
+		OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
+			context_callback),
+		OPT_BOOL('p', "show-function", &opt.funcname,
+			N_("show a line with the function name before matches")),
+		OPT_BOOL('W', "function-context", &opt.funcbody,
+			N_("show the surrounding function")),
+		OPT_GROUP(""),
+		OPT_CALLBACK('f', NULL, &opt, N_("file"),
+			N_("read patterns from file"), file_callback),
+		OPT_CALLBACK_F('e', NULL, &opt, N_("pattern"),
+			N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback),
+		OPT_CALLBACK_F(0, "and", &opt, NULL,
+			N_("combine patterns specified with -e"),
+			PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback),
+		OPT_BOOL_F(0, "or", &dummy, "", PARSE_OPT_NONEG),
+		OPT_CALLBACK_F(0, "not", &opt, NULL, "",
+			PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback),
+		OPT_CALLBACK_F('(', NULL, &opt, NULL, "",
+			PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
+			open_callback),
+		OPT_CALLBACK_F(')', NULL, &opt, NULL, "",
+			PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
+			close_callback),
+		OPT__QUIET(&opt.status_only,
+			   N_("indicate hit with exit status without output")),
+		OPT_BOOL(0, "all-match", &opt.all_match,
+			N_("show only matches from files that match all patterns")),
+		OPT_GROUP(""),
+		{ OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
+			N_("pager"), N_("show matching files in the pager"),
+			PARSE_OPT_OPTARG | PARSE_OPT_NOCOMPLETE,
+			NULL, (intptr_t)default_pager },
+		OPT_BOOL_F(0, "ext-grep", &external_grep_allowed__ignored,
+			   N_("allow calling of grep(1) (ignored by this build)"),
+			   PARSE_OPT_NOCOMPLETE),
+		OPT_INTEGER('m', "max-count", &opt.max_count,
+			N_("maximum number of results per file")),
+		OPT_END()
+	};
+	grep_prefix = prefix;
+
+	grep_init(&opt, the_repository);
+	git_config(grep_cmd_config, &opt);
+
+	/*
+	 * If there is no -- then the paths must exist in the working
+	 * tree.  If there is no explicit pattern specified with -e or
+	 * -f, we take the first unrecognized non option to be the
+	 * pattern, but then what follows it must be zero or more
+	 * valid refs up to the -- (if exists), and then existing
+	 * paths.  If there is an explicit pattern, then the first
+	 * unrecognized non option is the beginning of the refs list
+	 * that continues up to the -- (if exists), and then paths.
+	 */
+	argc = parse_options(argc, argv, prefix, options, grep_usage,
+			     PARSE_OPT_KEEP_DASHDASH |
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+
+	if (the_repository->gitdir) {
+		prepare_repo_settings(the_repository);
+		the_repository->settings.command_requires_full_index = 0;
+	}
+
+	if (use_index && !startup_info->have_repository) {
+		int fallback = 0;
+		git_config_get_bool("grep.fallbacktonoindex", &fallback);
+		if (fallback)
+			use_index = 0;
+		else
+			/* die the same way as if we did it at the beginning */
+			setup_git_directory();
+	}
+	/* Ignore --recurse-submodules if --no-index is given or implied */
+	if (!use_index)
+		recurse_submodules = 0;
+
+	/*
+	 * skip a -- separator; we know it cannot be
+	 * separating revisions from pathnames if
+	 * we haven't even had any patterns yet
+	 */
+	if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
+		argv++;
+		argc--;
+	}
+
+	/* First unrecognized non-option token */
+	if (argc > 0 && !opt.pattern_list) {
+		append_grep_pattern(&opt, argv[0], "command line", 0,
+				    GREP_PATTERN);
+		argv++;
+		argc--;
+	}
+
+	if (show_in_pager == default_pager)
+		show_in_pager = git_pager(1);
+	if (show_in_pager) {
+		opt.color = 0;
+		opt.name_only = 1;
+		opt.null_following_name = 1;
+		opt.output_priv = &path_list;
+		opt.output = append_path;
+		string_list_append(&path_list, show_in_pager);
+	}
+
+	if (!opt.pattern_list)
+		die(_("no pattern given"));
+
+	/* --only-matching has no effect with --invert. */
+	if (opt.invert)
+		opt.only_matching = 0;
+
+	/*
+	 * We have to find "--" in a separate pass, because its presence
+	 * influences how we will parse arguments that come before it.
+	 */
+	for (i = 0; i < argc; i++) {
+		if (!strcmp(argv[i], "--")) {
+			seen_dashdash = 1;
+			break;
+		}
+	}
+
+	/*
+	 * Resolve any rev arguments. If we have a dashdash, then everything up
+	 * to it must resolve as a rev. If not, then we stop at the first
+	 * non-rev and assume everything else is a path.
+	 */
+	allow_revs = use_index && !untracked;
+	for (i = 0; i < argc; i++) {
+		const char *arg = argv[i];
+		struct object_id oid;
+		struct object_context oc;
+		struct object *object;
+
+		if (!strcmp(arg, "--")) {
+			i++;
+			break;
+		}
+
+		if (!allow_revs) {
+			if (seen_dashdash)
+				die(_("--no-index or --untracked cannot be used with revs"));
+			break;
+		}
+
+		if (get_oid_with_context(the_repository, arg,
+					 GET_OID_RECORD_PATH,
+					 &oid, &oc)) {
+			if (seen_dashdash)
+				die(_("unable to resolve revision: %s"), arg);
+			break;
+		}
+
+		object = parse_object_or_die(&oid, arg);
+		if (!seen_dashdash)
+			verify_non_filename(prefix, arg);
+		add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
+		free(oc.path);
+	}
+
+	/*
+	 * Anything left over is presumed to be a path. But in the non-dashdash
+	 * "do what I mean" case, we verify and complain when that isn't true.
+	 */
+	if (!seen_dashdash) {
+		int j;
+		for (j = i; j < argc; j++)
+			verify_filename(prefix, argv[j], j == i && allow_revs);
+	}
+
+	parse_pathspec(&pathspec, 0,
+		       PATHSPEC_PREFER_CWD |
+		       (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
+		       prefix, argv + i);
+	pathspec.max_depth = opt.max_depth;
+	pathspec.recursive = 1;
+	pathspec.recurse_submodules = !!recurse_submodules;
+
+	if (recurse_submodules && untracked)
+		die(_("--untracked not supported with --recurse-submodules"));
+
+	/*
+	 * Optimize out the case where the amount of matches is limited to zero.
+	 * We do this to keep results consistent with GNU grep(1).
+	 */
+	if (opt.max_count == 0)
+		return 1;
+
+	if (show_in_pager) {
+		if (num_threads > 1)
+			warning(_("invalid option combination, ignoring --threads"));
+		num_threads = 1;
+	} else if (!HAVE_THREADS && num_threads > 1) {
+		warning(_("no threads support, ignoring --threads"));
+		num_threads = 1;
+	} else if (num_threads < 0)
+		die(_("invalid number of threads specified (%d)"), num_threads);
+	else if (num_threads == 0)
+		num_threads = HAVE_THREADS ? online_cpus() : 1;
+
+	if (num_threads > 1) {
+		if (!HAVE_THREADS)
+			BUG("Somebody got num_threads calculation wrong!");
+		if (!(opt.name_only || opt.unmatch_name_only || opt.count)
+		    && (opt.pre_context || opt.post_context ||
+			opt.file_break || opt.funcbody))
+			skip_first_line = 1;
+
+		/*
+		 * Pre-read gitmodules (if not read already) and force eager
+		 * initialization of packed_git to prevent racy lazy
+		 * reading/initialization once worker threads are started.
+		 */
+		if (recurse_submodules)
+			repo_read_gitmodules(the_repository, 1);
+		if (startup_info->have_repository)
+			(void)get_packed_git(the_repository);
+
+		start_threads(&opt);
+	} else {
+		/*
+		 * The compiled patterns on the main path are only
+		 * used when not using threading. Otherwise
+		 * start_threads() above calls compile_grep_patterns()
+		 * for each thread.
+		 */
+		compile_grep_patterns(&opt);
+	}
+
+	if (show_in_pager && (cached || list.nr))
+		die(_("--open-files-in-pager only works on the worktree"));
+
+	if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
+		const char *pager = path_list.items[0].string;
+		int len = strlen(pager);
+
+		if (len > 4 && is_dir_sep(pager[len - 5]))
+			pager += len - 4;
+
+		if (opt.ignore_case && !strcmp("less", pager))
+			string_list_append(&path_list, "-I");
+
+		if (!strcmp("less", pager) || !strcmp("vi", pager)) {
+			struct strbuf buf = STRBUF_INIT;
+			strbuf_addf(&buf, "+/%s%s",
+					strcmp("less", pager) ? "" : "*",
+					opt.pattern_list->pattern);
+			string_list_append_nodup(&path_list,
+						 strbuf_detach(&buf, NULL));
+		}
+	}
+
+	if (!show_in_pager && !opt.status_only)
+		setup_pager();
+
+	die_for_incompatible_opt3(!use_index, "--no-index",
+				  untracked, "--untracked",
+				  cached, "--cached");
+
+	if (!use_index || untracked) {
+		int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
+		hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
+	} else if (0 <= opt_exclude) {
+		die(_("--[no-]exclude-standard cannot be used for tracked contents"));
+	} else if (!list.nr) {
+		if (!cached)
+			setup_work_tree();
+
+		hit = grep_cache(&opt, &pathspec, cached);
+	} else {
+		if (cached)
+			die(_("both --cached and trees are given"));
+
+		hit = grep_objects(&opt, &pathspec, &list);
+	}
+
+	if (num_threads > 1)
+		hit |= wait_all();
+	if (hit && show_in_pager)
+		run_pager(&opt, prefix);
+	clear_pathspec(&pathspec);
+	string_list_clear(&path_list, 0);
+	free_grep_patterns(&opt);
+	object_array_clear(&list);
+	free_repos();
+	return !hit;
+}