unpack-trees.[ch]: embed "dir" in "struct unpack_trees_options"

Change the "struct dir" in "struct unpack_trees_options" away from a
pointer to being embedded in the struct itself, this mean that we can
initialize it with our new UNPACK_TREES_OPTIONS_INIT macro.

As it turned out nothing actually needed to provide its own "struct
dir" to this API, there's another patch to "hide" the struct instead,
see the discussion at [1], but I think just allocating it on the stack
along with the rest makes more sense.

This fixes a memory leak in "builtin/checkout.c" that's been there
since the clear_unpack_trees_porcelain() function was added in
1c41d28 (unpack_trees_options: free messages when done,
2018-05-21), i.e. we still had a memory leak from allocating the "dir"
member here. That "dir" member had in turn been with us ever since
782c2d6 (Build in checkout, 2008-02-07).

This fixes that memory leak, and allows us to remove the boilerplate
dir_clear() elsewhere in favor of just using
clear_unpack_trees_porcelain().

1. https://lore.kernel.org/git/87ilyjviiy.fsf@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>

builtin/checkout.c

@@ -745,9 +745,8 @@ static int merge_working_tree(const struct checkout_opts *opts,
 				       &new_branch_info->commit->object.oid :
 				       &new_branch_info->oid, NULL);
 		if (opts->overwrite_ignore) {
-			topts.dir = xcalloc(1, sizeof(*topts.dir));
-			topts.dir->flags |= DIR_SHOW_IGNORED;
-			setup_standard_excludes(topts.dir);
+			topts.dir.flags |= DIR_SHOW_IGNORED;
+			setup_standard_excludes(&topts.dir);
 		}
 		tree = parse_tree_indirect(old_branch_info->commit ?
 					   &old_branch_info->commit->object.oid :

builtin/read-tree.c

@@ -53,20 +53,17 @@ static int index_output_cb(const struct option *opt, const char *arg,
 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
 				    int unset)
 {
-	struct dir_struct *dir;
 	struct unpack_trees_options *opts;
 
 	BUG_ON_OPT_NEG(unset);
 
 	opts = (struct unpack_trees_options *)opt->value;
 
-	if (opts->dir)
+	if (opts->dir.exclude_per_dir)
 		die("more than one --exclude-per-directory given.");
 
-	dir = xcalloc(1, sizeof(*opts->dir));
-	dir->flags |= DIR_SHOW_IGNORED;
-	dir->exclude_per_dir = arg;
-	opts->dir = dir;
+	opts->dir.flags |= DIR_SHOW_IGNORED;
+	opts->dir.exclude_per_dir = arg;
 	/* We do not need to nor want to do read-directory
 	 * here; we are merely interested in reusing the
 	 * per directory ignore stack mechanism.
@@ -208,7 +205,7 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 	if ((opts.update || opts.index_only) && !opts.merge)
 		die("%s is meaningless without -m, --reset, or --prefix",
 		    opts.update ? "-u" : "-i");
-	if ((opts.dir && !opts.update))
+	if ((opts.dir.exclude_per_dir && !opts.update))
 		die("--exclude-per-directory is meaningless unless -u");
 	if (opts.merge && !opts.index_only)
 		setup_work_tree();

merge-ort.c

@@ -4045,9 +4045,8 @@ static int checkout(struct merge_options *opt,
 	unpack_opts.verbose_update = (opt->verbosity > 2);
 	unpack_opts.fn = twoway_merge;
 	if (1/* FIXME: opts->overwrite_ignore*/) {
-		CALLOC_ARRAY(unpack_opts.dir, 1);
-		unpack_opts.dir->flags |= DIR_SHOW_IGNORED;
-		setup_standard_excludes(unpack_opts.dir);
+		unpack_opts.dir.flags |= DIR_SHOW_IGNORED;
+		setup_standard_excludes(&unpack_opts.dir);
 	}
 	parse_tree(prev);
 	init_tree_desc(&trees[0], prev->buffer, prev->size);
@@ -4056,8 +4055,6 @@ static int checkout(struct merge_options *opt,
 
 	ret = unpack_trees(2, trees, &unpack_opts);
 	clear_unpack_trees_porcelain(&unpack_opts);
-	dir_clear(unpack_opts.dir);
-	FREE_AND_NULL(unpack_opts.dir);
 	return ret;
 }
 

merge.c

@@ -50,10 +50,9 @@ int checkout_fast_forward(struct repository *r,
 			  int overwrite_ignore)
 {
 	struct tree *trees[MAX_UNPACK_TREES];
-	struct unpack_trees_options opts;
+	struct unpack_trees_options opts = UNPACK_TREES_OPTIONS_INIT;
 	struct tree_desc t[MAX_UNPACK_TREES];
 	int i, nr_trees = 0;
-	struct dir_struct dir = DIR_INIT;
 	struct lock_file lock_file = LOCK_INIT;
 
 	refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
@@ -79,11 +78,9 @@ int checkout_fast_forward(struct repository *r,
 		init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
 	}
 
-	memset(&opts, 0, sizeof(opts));
 	if (overwrite_ignore) {
-		dir.flags |= DIR_SHOW_IGNORED;
-		setup_standard_excludes(&dir);
-		opts.dir = &dir;
+		opts.dir.flags |= DIR_SHOW_IGNORED;
+		setup_standard_excludes(&opts.dir);
 	}
 
 	opts.head_idx = 1;
@@ -101,7 +98,6 @@ int checkout_fast_forward(struct repository *r,
 		clear_unpack_trees_porcelain(&opts);
 		return -1;
 	}
-	dir_clear(&dir);
 	clear_unpack_trees_porcelain(&opts);
 
 	if (write_locked_index(r->index, &lock_file, COMMIT_LOCK))

unpack-trees.c

@@ -192,6 +192,7 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
 void clear_unpack_trees_porcelain(struct unpack_trees_options *opts)
 {
 	strvec_clear(&opts->msgs_to_free);
+	dir_clear(&opts->dir);
 	memset(opts->msgs, 0, sizeof(opts->msgs));
 }
 
@@ -2081,7 +2082,7 @@ static int verify_clean_subdirectory(const struct cache_entry *ce,
 	 */
 	int namelen;
 	int i;
-	struct dir_struct d;
+	struct dir_struct d = DIR_INIT;
 	char *pathbuf;
 	int cnt = 0;
 
@@ -2132,9 +2133,7 @@ static int verify_clean_subdirectory(const struct cache_entry *ce,
 	 */
 	pathbuf = xstrfmt("%.*s/", namelen, ce->name);
 
-	memset(&d, 0, sizeof(d));
-	if (o->dir)
-		d.exclude_per_dir = o->dir->exclude_per_dir;
+	d.exclude_per_dir = o->dir.exclude_per_dir;
 	i = read_directory(&d, o->src_index, pathbuf, namelen+1, NULL);
 	if (i)
 		return add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
@@ -2175,8 +2174,7 @@ static int check_ok_to_remove(const char *name, int len, int dtype,
 	if (ignore_case && icase_exists(o, name, len, st))
 		return 0;
 
-	if (o->dir &&
-	    is_excluded(o->dir, o->src_index, name, &dtype))
+	if (is_excluded(&o->dir, o->src_index, name, &dtype))
 		/*
 		 * ce->name is explicitly excluded, so it is Ok to
 		 * overwrite it.

unpack-trees.h

@@ -5,6 +5,7 @@
 #include "strvec.h"
 #include "string-list.h"
 #include "tree-walk.h"
+#include "dir.h"
 
 #define MAX_UNPACK_TREES MAX_TRAVERSE_TREES
 
@@ -66,7 +67,7 @@ struct unpack_trees_options {
 		     dry_run;
 	const char *prefix;
 	int cache_bottom;
-	struct dir_struct *dir;
+	struct dir_struct dir;
 	struct pathspec *pathspec;
 	merge_fn_t fn;
 	const char *msgs[NB_UNPACK_TREES_WARNING_TYPES];
@@ -90,7 +91,9 @@ struct unpack_trees_options {
 	struct pattern_list *pl; /* for internal use */
 	struct checkout_metadata meta;
 };
-#define UNPACK_TREES_OPTIONS_INIT { 0 }
+#define UNPACK_TREES_OPTIONS_INIT { \
+	.dir = DIR_INIT, \
+}
 
 int unpack_trees(unsigned n, struct tree_desc *t,
 		 struct unpack_trees_options *options);