diff --git a/blame.c b/blame.c
index c3060de2f8..2893f3c103 100644
--- a/blame.c
+++ b/blame.c
@@ -209,7 +209,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 
 		switch (st.st_mode & S_IFMT) {
 		case S_IFREG:
-			if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
+			if (opt->flags.allow_textconv &&
 			    textconv_object(read_from, mode, &null_oid, 0, &buf_ptr, &buf_len))
 				strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1);
 			else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
@@ -293,7 +293,7 @@ static void fill_origin_blob(struct diff_options *opt,
 		unsigned long file_size;
 
 		(*num_read_blob)++;
-		if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
+		if (opt->flags.allow_textconv &&
 		    textconv_object(o->path, o->mode, &o->blob_oid, 1, &file->ptr, &file_size))
 			;
 		else
@@ -541,7 +541,7 @@ static struct blame_origin *find_origin(struct commit *parent,
 	 * same and diff-tree is fairly efficient about this.
 	 */
 	diff_setup(&diff_opts);
-	DIFF_OPT_SET(&diff_opts, RECURSIVE);
+	diff_opts.flags.recursive = 1;
 	diff_opts.detect_rename = 0;
 	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 	paths[0] = origin->path;
@@ -615,7 +615,7 @@ static struct blame_origin *find_rename(struct commit *parent,
 	int i;
 
 	diff_setup(&diff_opts);
-	DIFF_OPT_SET(&diff_opts, RECURSIVE);
+	diff_opts.flags.recursive = 1;
 	diff_opts.detect_rename = DIFF_DETECT_RENAME;
 	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 	diff_opts.single_follow = origin->path;
@@ -1238,7 +1238,7 @@ static void find_copy_in_parent(struct blame_scoreboard *sb,
 		return; /* nothing remains for this target */
 
 	diff_setup(&diff_opts);
-	DIFF_OPT_SET(&diff_opts, RECURSIVE);
+	diff_opts.flags.recursive = 1;
 	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 
 	diff_setup_done(&diff_opts);
@@ -1253,7 +1253,7 @@ static void find_copy_in_parent(struct blame_scoreboard *sb,
 	if ((opt & PICKAXE_BLAME_COPY_HARDEST)
 	    || ((opt & PICKAXE_BLAME_COPY_HARDER)
 		&& (!porigin || strcmp(target->path, porigin->path))))
-		DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
+		diff_opts.flags.find_copies_harder = 1;
 
 	if (is_null_oid(&target->commit->object.oid))
 		do_diff_cache(&parent->tree->object.oid, &diff_opts);
@@ -1262,7 +1262,7 @@ static void find_copy_in_parent(struct blame_scoreboard *sb,
 			      &target->commit->tree->object.oid,
 			      "", &diff_opts);
 
-	if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
+	if (!diff_opts.flags.find_copies_harder)
 		diffcore_std(&diff_opts);
 
 	do {
@@ -1825,7 +1825,7 @@ void setup_scoreboard(struct blame_scoreboard *sb, const char *path, struct blam
 		if (fill_blob_sha1_and_mode(o))
 			die(_("no such path %s in %s"), path, final_commit_name);
 
-		if (DIFF_OPT_TST(&sb->revs->diffopt, ALLOW_TEXTCONV) &&
+		if (sb->revs->diffopt.flags.allow_textconv &&
 		    textconv_object(path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf,
 				    &sb->final_buf_size))
 			;
diff --git a/builtin/add.c b/builtin/add.c
index a648cf4c56..8d08e99e92 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -116,7 +116,7 @@ int add_files_to_cache(const char *prefix,
 	rev.diffopt.output_format = DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = update_callback;
 	rev.diffopt.format_callback_data = &data;
-	rev.diffopt.flags |= DIFF_OPT_OVERRIDE_SUBMODULE_CONFIG;
+	rev.diffopt.flags.override_submodule_config = 1;
 	rev.max_count = 0; /* do not compare unmerged paths with stage #2 */
 	run_diff_files(&rev, DIFF_RACY_IS_MODIFIED);
 	clear_pathspec(&rev.prune_data);
@@ -218,7 +218,7 @@ static int edit_patch(int argc, const char **argv, const char *prefix)
 	argc = setup_revisions(argc, argv, &rev, NULL);
 	rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 	rev.diffopt.use_color = 0;
-	DIFF_OPT_SET(&rev.diffopt, IGNORE_DIRTY_SUBMODULES);
+	rev.diffopt.flags.ignore_dirty_submodules = 1;
 	out = open(file, O_CREAT | O_WRONLY, 0666);
 	if (out < 0)
 		die(_("Could not open '%s' for writing."), file);
diff --git a/builtin/am.c b/builtin/am.c
index 4b6f1534f8..92c4853505 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1157,9 +1157,9 @@ static int index_has_changes(struct strbuf *sb)
 		struct diff_options opt;
 
 		diff_setup(&opt);
-		DIFF_OPT_SET(&opt, EXIT_WITH_STATUS);
+		opt.flags.exit_with_status = 1;
 		if (!sb)
-			DIFF_OPT_SET(&opt, QUICK);
+			opt.flags.quick = 1;
 		do_diff_cache(&head, &opt);
 		diffcore_std(&opt);
 		for (i = 0; sb && i < diff_queued_diff.nr; i++) {
@@ -1168,7 +1168,7 @@ static int index_has_changes(struct strbuf *sb)
 			strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path);
 		}
 		diff_flush(&opt);
-		return DIFF_OPT_TST(&opt, HAS_CHANGES) != 0;
+		return opt.flags.has_changes != 0;
 	} else {
 		for (i = 0; sb && i < active_nr; i++) {
 			if (i)
@@ -1409,8 +1409,8 @@ static void write_commit_patch(const struct am_state *state, struct commit *comm
 	rev_info.show_root_diff = 1;
 	rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
 	rev_info.no_commit_id = 1;
-	DIFF_OPT_SET(&rev_info.diffopt, BINARY);
-	DIFF_OPT_SET(&rev_info.diffopt, FULL_INDEX);
+	rev_info.diffopt.flags.binary = 1;
+	rev_info.diffopt.flags.full_index = 1;
 	rev_info.diffopt.use_color = 0;
 	rev_info.diffopt.file = fp;
 	rev_info.diffopt.close_file = 1;
diff --git a/builtin/blame.c b/builtin/blame.c
index 67adaef4d8..005f55aaa2 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -708,8 +708,8 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 	git_config(git_blame_config, &output_option);
 	init_revisions(&revs, NULL);
 	revs.date_mode = blame_date_mode;
-	DIFF_OPT_SET(&revs.diffopt, ALLOW_TEXTCONV);
-	DIFF_OPT_SET(&revs.diffopt, FOLLOW_RENAMES);
+	revs.diffopt.flags.allow_textconv = 1;
+	revs.diffopt.flags.follow_renames = 1;
 
 	save_commit_buffer = 0;
 	dashdash_pos = 0;
@@ -734,9 +734,9 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 		parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
 	}
 parse_done:
-	no_whole_file_rename = !DIFF_OPT_TST(&revs.diffopt, FOLLOW_RENAMES);
+	no_whole_file_rename = !revs.diffopt.flags.follow_renames;
 	xdl_opts |= revs.diffopt.xdl_opts & XDF_INDENT_HEURISTIC;
-	DIFF_OPT_CLR(&revs.diffopt, FOLLOW_RENAMES);
+	revs.diffopt.flags.follow_renames = 0;
 	argc = parse_options_end(&ctx);
 
 	if (incremental || (output_option & OUTPUT_PORCELAIN)) {
@@ -803,7 +803,7 @@ parse_done:
 	}
 	blame_date_width -= 1; /* strip the null */
 
-	if (DIFF_OPT_TST(&revs.diffopt, FIND_COPIES_HARDER))
+	if (revs.diffopt.flags.find_copies_harder)
 		opt |= (PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE |
 			PICKAXE_BLAME_COPY_HARDER);
 
diff --git a/builtin/commit.c b/builtin/commit.c
index c38542ee46..605ea8c0e9 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -912,11 +912,12 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 			 * submodules which were manually staged, which would
 			 * be really confusing.
 			 */
-			int diff_flags = DIFF_OPT_OVERRIDE_SUBMODULE_CONFIG;
+			struct diff_flags flags = DIFF_FLAGS_INIT;
+			flags.override_submodule_config = 1;
 			if (ignore_submodule_arg &&
 			    !strcmp(ignore_submodule_arg, "all"))
-				diff_flags |= DIFF_OPT_IGNORE_SUBMODULES;
-			commitable = index_differs_from(parent, diff_flags, 1);
+				flags.ignore_submodules = 1;
+			commitable = index_differs_from(parent, &flags, 1);
 		}
 	}
 	strbuf_release(&committer_ident);
diff --git a/builtin/diff.c b/builtin/diff.c
index aa6f746795..9808d062a8 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -44,7 +44,7 @@ static void stuff_change(struct diff_options *opt,
 	    !oidcmp(old_oid, new_oid) && (old_mode == new_mode))
 		return;
 
-	if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
+	if (opt->flags.reverse_diff) {
 		SWAP(old_mode, new_mode);
 		SWAP(old_oid, new_oid);
 		SWAP(old_path, new_path);
@@ -349,8 +349,8 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 	rev.diffopt.stat_graph_width = -1;
 
 	/* Default to let external and textconv be used */
-	DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
-	DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
+	rev.diffopt.flags.allow_external = 1;
+	rev.diffopt.flags.allow_textconv = 1;
 
 	if (nongit)
 		die(_("Not a git repository"));
@@ -360,7 +360,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 		diff_setup_done(&rev.diffopt);
 	}
 
-	DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
+	rev.diffopt.flags.recursive = 1;
 
 	setup_diff_pager(&rev.diffopt);
 
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index d74c73f777..f8fe04ca53 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -1066,7 +1066,7 @@ int cmd_fast_export(int argc, const char **argv, const char *prefix)
 		die("revision walk setup failed");
 	revs.diffopt.format_callback = show_filemodify;
 	revs.diffopt.format_callback_data = &paths_of_changed_objects;
-	DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
+	revs.diffopt.flags.recursive = 1;
 	while ((commit = get_revision(&revs))) {
 		if (has_unshown_parent(commit)) {
 			add_object_array(&commit->object, NULL, &commits);
diff --git a/builtin/log.c b/builtin/log.c
index ba9d4cd786..6c1fa896ad 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -121,20 +121,19 @@ static void cmd_log_init_defaults(struct rev_info *rev)
 	if (fmt_pretty)
 		get_commit_format(fmt_pretty, rev);
 	if (default_follow)
-		DIFF_OPT_SET(&rev->diffopt, DEFAULT_FOLLOW_RENAMES);
+		rev->diffopt.flags.default_follow_renames = 1;
 	rev->verbose_header = 1;
-	DIFF_OPT_SET(&rev->diffopt, RECURSIVE);
+	rev->diffopt.flags.recursive = 1;
 	rev->diffopt.stat_width = -1; /* use full terminal width */
 	rev->diffopt.stat_graph_width = -1; /* respect statGraphWidth config */
 	rev->abbrev_commit = default_abbrev_commit;
 	rev->show_root_diff = default_show_root;
 	rev->subject_prefix = fmt_patch_subject_prefix;
 	rev->show_signature = default_show_signature;
-	DIFF_OPT_SET(&rev->diffopt, ALLOW_TEXTCONV);
+	rev->diffopt.flags.allow_textconv = 1;
 
 	if (default_date_mode)
 		parse_date_format(default_date_mode, &rev->date_mode);
-	rev->diffopt.touched_flags = 0;
 }
 
 static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
@@ -182,7 +181,7 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 		init_display_notes(&rev->notes_opt);
 
 	if (rev->diffopt.pickaxe || rev->diffopt.filter ||
-	    DIFF_OPT_TST(&rev->diffopt, FOLLOW_RENAMES))
+	    rev->diffopt.flags.follow_renames)
 		rev->always_show_header = 0;
 
 	if (source)
@@ -392,7 +391,7 @@ static int cmd_log_walk(struct rev_info *rev)
 		fclose(rev->diffopt.file);
 
 	if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF &&
-	    DIFF_OPT_TST(&rev->diffopt, CHECK_FAILED)) {
+	    rev->diffopt.flags.check_failed) {
 		return 02;
 	}
 	return diff_result_code(&rev->diffopt, 0);
@@ -484,8 +483,8 @@ static int show_blob_object(const struct object_id *oid, struct rev_info *rev, c
 	unsigned long size;
 
 	fflush(rev->diffopt.file);
-	if (!DIFF_OPT_TOUCHED(&rev->diffopt, ALLOW_TEXTCONV) ||
-	    !DIFF_OPT_TST(&rev->diffopt, ALLOW_TEXTCONV))
+	if (!rev->diffopt.flags.textconv_set_via_cmdline ||
+	    !rev->diffopt.flags.allow_textconv)
 		return stream_blob_to_fd(1, oid, NULL, 0);
 
 	if (get_oid_with_context(obj_name, GET_OID_RECORD_PATH,
@@ -667,9 +666,9 @@ int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 static void log_setup_revisions_tweak(struct rev_info *rev,
 				      struct setup_revision_opt *opt)
 {
-	if (DIFF_OPT_TST(&rev->diffopt, DEFAULT_FOLLOW_RENAMES) &&
+	if (rev->diffopt.flags.default_follow_renames &&
 	    rev->prune_data.nr == 1)
-		DIFF_OPT_SET(&rev->diffopt, FOLLOW_RENAMES);
+		rev->diffopt.flags.follow_renames = 1;
 
 	/* Turn --cc/-c into -p --cc/-c when -p was not given */
 	if (!rev->diffopt.output_format && rev->combine_merges)
@@ -1341,7 +1340,7 @@ static void prepare_bases(struct base_tree_info *bases,
 		return;
 
 	diff_setup(&diffopt);
-	DIFF_OPT_SET(&diffopt, RECURSIVE);
+	diffopt.flags.recursive = 1;
 	diff_setup_done(&diffopt);
 
 	oidcpy(&bases->base_commit, &base->object.oid);
@@ -1512,7 +1511,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	rev.verbose_header = 1;
 	rev.diff = 1;
 	rev.max_parents = 1;
-	DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
+	rev.diffopt.flags.recursive = 1;
 	rev.subject_prefix = fmt_patch_subject_prefix;
 	memset(&s_r_opt, 0, sizeof(s_r_opt));
 	s_r_opt.def = "HEAD";
@@ -1613,8 +1612,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 
 	rev.zero_commit = zero_commit;
 
-	if (!DIFF_OPT_TST(&rev.diffopt, TEXT) && !no_binary_diff)
-		DIFF_OPT_SET(&rev.diffopt, BINARY);
+	if (!rev.diffopt.flags.text && !no_binary_diff)
+		rev.diffopt.flags.binary = 1;
 
 	if (rev.show_notes)
 		init_display_notes(&rev.notes_opt);
diff --git a/builtin/merge-ours.c b/builtin/merge-ours.c
index beb0623d56..c84c6e05e9 100644
--- a/builtin/merge-ours.c
+++ b/builtin/merge-ours.c
@@ -26,7 +26,7 @@ int cmd_merge_ours(int argc, const char **argv, const char *prefix)
 	 */
 	if (read_cache() < 0)
 		die_errno("read_cache failed");
-	if (index_differs_from("HEAD", 0, 0))
+	if (index_differs_from("HEAD", NULL, 0))
 		exit(2);
 	exit(0);
 }
diff --git a/builtin/reset.c b/builtin/reset.c
index d4003f76ab..906e541658 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -166,7 +166,7 @@ static int read_from_tree(const struct pathspec *pathspec,
 	opt.output_format = DIFF_FORMAT_CALLBACK;
 	opt.format_callback = update_index_from_diff;
 	opt.format_callback_data = &intent_to_add;
-	opt.flags |= DIFF_OPT_OVERRIDE_SUBMODULE_CONFIG;
+	opt.flags.override_submodule_config = 1;
 
 	if (do_diff_cache(tree_oid, &opt))
 		return 1;
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 9bf8d5991c..8034d2eff2 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -294,7 +294,7 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	if (revs.bisect)
 		bisect_list = 1;
 
-	if (DIFF_OPT_TST(&revs.diffopt, QUICK))
+	if (revs.diffopt.flags.quick)
 		info.flags |= REV_LIST_QUIET;
 	for (i = 1 ; i < argc; i++) {
 		const char *arg = argv[i];
diff --git a/combine-diff.c b/combine-diff.c
index 82f6070977..2505de119a 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -898,7 +898,7 @@ static void show_combined_header(struct combine_diff_path *elem,
 				 int show_file_header)
 {
 	struct diff_options *opt = &rev->diffopt;
-	int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? GIT_SHA1_HEXSZ : DEFAULT_ABBREV;
+	int abbrev = opt->flags.full_index ? GIT_SHA1_HEXSZ : DEFAULT_ABBREV;
 	const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 	const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 	const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
@@ -987,7 +987,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 	userdiff = userdiff_find_by_path(elem->path);
 	if (!userdiff)
 		userdiff = userdiff_find_by_name("default");
-	if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV))
+	if (opt->flags.allow_textconv)
 		textconv = userdiff_get_textconv(userdiff);
 
 	/* Read the result of merge first */
@@ -1413,8 +1413,8 @@ void diff_tree_combined(const struct object_id *oid,
 
 	diffopts = *opt;
 	copy_pathspec(&diffopts.pathspec, &opt->pathspec);
-	DIFF_OPT_SET(&diffopts, RECURSIVE);
-	DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
+	diffopts.flags.recursive = 1;
+	diffopts.flags.allow_external = 0;
 
 	/* find set of paths that everybody touches
 	 *
@@ -1435,7 +1435,7 @@ void diff_tree_combined(const struct object_id *oid,
 	 * NOTE please keep this semantically in sync with diffcore_std()
 	 */
 	need_generic_pathscan = opt->skip_stat_unmatch	||
-			DIFF_OPT_TST(opt, FOLLOW_RENAMES)	||
+			opt->flags.follow_renames	||
 			opt->break_opt != -1	||
 			opt->detect_rename	||
 			opt->pickaxe		||
diff --git a/diff-lib.c b/diff-lib.c
index d2ea02f4d7..731f0886d6 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -71,14 +71,15 @@ static int match_stat_with_submodule(struct diff_options *diffopt,
 {
 	int changed = ce_match_stat(ce, st, ce_option);
 	if (S_ISGITLINK(ce->ce_mode)) {
-		unsigned orig_flags = diffopt->flags;
-		if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
+		struct diff_flags orig_flags = diffopt->flags;
+		if (!diffopt->flags.override_submodule_config)
 			set_diffopt_flags_from_submodule_config(diffopt, ce->name);
-		if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
+		if (diffopt->flags.ignore_submodules)
 			changed = 0;
-		else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
-		    && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
-			*dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
+		else if (!diffopt->flags.ignore_dirty_submodules &&
+			 (!changed || diffopt->flags.dirty_submodules))
+			*dirty_submodule = is_submodule_modified(ce->name,
+								 diffopt->flags.ignore_untracked_in_submodules);
 		diffopt->flags = orig_flags;
 	}
 	return changed;
@@ -228,7 +229,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 
 		if (!changed && !dirty_submodule) {
 			ce_mark_uptodate(ce);
-			if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
+			if (!revs->diffopt.flags.find_copies_harder)
 				continue;
 		}
 		oldmode = ce->ce_mode;
@@ -362,7 +363,7 @@ static int show_modified(struct rev_info *revs,
 
 	oldmode = old->ce_mode;
 	if (mode == oldmode && !oidcmp(oid, &old->oid) && !dirty_submodule &&
-	    !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
+	    !revs->diffopt.flags.find_copies_harder)
 		return 0;
 
 	diff_change(&revs->diffopt, oldmode, mode,
@@ -493,7 +494,7 @@ static int diff_cache(struct rev_info *revs,
 	opts.head_idx = 1;
 	opts.index_only = cached;
 	opts.diff_index_cached = (cached &&
-				  !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
+				  !revs->diffopt.flags.find_copies_harder);
 	opts.merge = 1;
 	opts.fn = oneway_diff;
 	opts.unpack_data = revs;
@@ -534,7 +535,7 @@ int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 	return 0;
 }
 
-int index_differs_from(const char *def, int diff_flags,
+int index_differs_from(const char *def, const struct diff_flags *flags,
 		       int ita_invisible_in_index)
 {
 	struct rev_info rev;
@@ -544,11 +545,12 @@ int index_differs_from(const char *def, int diff_flags,
 	memset(&opt, 0, sizeof(opt));
 	opt.def = def;
 	setup_revisions(0, NULL, &rev, &opt);
-	DIFF_OPT_SET(&rev.diffopt, QUICK);
-	DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
-	rev.diffopt.flags |= diff_flags;
+	rev.diffopt.flags.quick = 1;
+	rev.diffopt.flags.exit_with_status = 1;
+	if (flags)
+		diff_flags_or(&rev.diffopt.flags, flags);
 	rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 	run_diff_index(&rev, 1);
 	object_array_clear(&rev.pending);
-	return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
+	return (rev.diffopt.flags.has_changes != 0);
 }
diff --git a/diff-no-index.c b/diff-no-index.c
index 80ff17d460..0ed5f0f496 100644
--- a/diff-no-index.c
+++ b/diff-no-index.c
@@ -184,7 +184,7 @@ static int queue_diff(struct diff_options *o,
 	} else {
 		struct diff_filespec *d1, *d2;
 
-		if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
+		if (o->flags.reverse_diff) {
 			SWAP(mode1, mode2);
 			SWAP(name1, name2);
 		}
@@ -276,16 +276,16 @@ void diff_no_index(struct rev_info *revs,
 	if (!revs->diffopt.output_format)
 		revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 
-	DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
+	revs->diffopt.flags.no_index = 1;
 
-	DIFF_OPT_SET(&revs->diffopt, RELATIVE_NAME);
+	revs->diffopt.flags.relative_name = 1;
 	revs->diffopt.prefix = prefix;
 
 	revs->max_count = -2;
 	diff_setup_done(&revs->diffopt);
 
 	setup_diff_pager(&revs->diffopt);
-	DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
+	revs->diffopt.flags.exit_with_status = 1;
 
 	if (queue_diff(&revs->diffopt, paths[0], paths[1]))
 		exit(1);
diff --git a/diff.c b/diff.c
index 1898dd307d..0763e89263 100644
--- a/diff.c
+++ b/diff.c
@@ -124,18 +124,18 @@ static int parse_dirstat_params(struct diff_options *options, const char *params
 	for (i = 0; i < params.nr; i++) {
 		const char *p = params.items[i].string;
 		if (!strcmp(p, "changes")) {
-			DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
-			DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
+			options->flags.dirstat_by_line = 0;
+			options->flags.dirstat_by_file = 0;
 		} else if (!strcmp(p, "lines")) {
-			DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
-			DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
+			options->flags.dirstat_by_line = 1;
+			options->flags.dirstat_by_file = 0;
 		} else if (!strcmp(p, "files")) {
-			DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
-			DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
+			options->flags.dirstat_by_line = 0;
+			options->flags.dirstat_by_file = 1;
 		} else if (!strcmp(p, "noncumulative")) {
-			DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
+			options->flags.dirstat_cumulative = 0;
 		} else if (!strcmp(p, "cumulative")) {
-			DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
+			options->flags.dirstat_cumulative = 1;
 		} else if (isdigit(*p)) {
 			char *end;
 			int permille = strtoul(p, &end, 10) * 10;
@@ -1412,7 +1412,7 @@ static void emit_rewrite_diff(const char *name_a,
 	struct emit_callback ecbdata;
 	struct strbuf out = STRBUF_INIT;
 
-	if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
+	if (diff_mnemonic_prefix && o->flags.reverse_diff) {
 		a_prefix = o->b_prefix;
 		b_prefix = o->a_prefix;
 	} else {
@@ -2660,7 +2660,7 @@ static void show_dirstat(struct diff_options *options)
 	dir.alloc = 0;
 	dir.nr = 0;
 	dir.permille = options->dirstat_permille;
-	dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
+	dir.cumulative = options->flags.dirstat_cumulative;
 
 	changed = 0;
 	for (i = 0; i < q->nr; i++) {
@@ -2686,7 +2686,7 @@ static void show_dirstat(struct diff_options *options)
 			goto found_damage;
 		}
 
-		if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
+		if (options->flags.dirstat_by_file) {
 			/*
 			 * In --dirstat-by-file mode, we don't really need to
 			 * look at the actual file contents at all.
@@ -2761,7 +2761,7 @@ static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *o
 	dir.alloc = 0;
 	dir.nr = 0;
 	dir.permille = options->dirstat_permille;
-	dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
+	dir.cumulative = options->flags.dirstat_cumulative;
 
 	changed = 0;
 	for (i = 0; i < data->nr; i++) {
@@ -3048,7 +3048,7 @@ static void builtin_diff(const char *name_a,
 	const char *line_prefix = diff_line_prefix(o);
 
 	diff_set_mnemonic_prefix(o, "a/", "b/");
-	if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
+	if (o->flags.reverse_diff) {
 		a_prefix = o->b_prefix;
 		b_prefix = o->a_prefix;
 	} else {
@@ -3072,7 +3072,7 @@ static void builtin_diff(const char *name_a,
 		return;
 	}
 
-	if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
+	if (o->flags.allow_textconv) {
 		textconv_one = get_textconv(one);
 		textconv_two = get_textconv(two);
 	}
@@ -3132,13 +3132,13 @@ static void builtin_diff(const char *name_a,
 				 header.len, 0);
 		strbuf_reset(&header);
 		goto free_ab_and_return;
-	} else if (!DIFF_OPT_TST(o, TEXT) &&
+	} else if (!o->flags.text &&
 	    ( (!textconv_one && diff_filespec_is_binary(one)) ||
 	      (!textconv_two && diff_filespec_is_binary(two)) )) {
 		struct strbuf sb = STRBUF_INIT;
 		if (!one->data && !two->data &&
 		    S_ISREG(one->mode) && S_ISREG(two->mode) &&
-		    !DIFF_OPT_TST(o, BINARY)) {
+		    !o->flags.binary) {
 			if (!oidcmp(&one->oid, &two->oid)) {
 				if (must_show_header)
 					emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
@@ -3167,7 +3167,7 @@ static void builtin_diff(const char *name_a,
 		}
 		emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
 		strbuf_reset(&header);
-		if (DIFF_OPT_TST(o, BINARY))
+		if (o->flags.binary)
 			emit_binary_diff(o, &mf1, &mf2);
 		else {
 			strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
@@ -3213,7 +3213,7 @@ static void builtin_diff(const char *name_a,
 		xecfg.ctxlen = o->context;
 		xecfg.interhunkctxlen = o->interhunkcontext;
 		xecfg.flags = XDL_EMIT_FUNCNAMES;
-		if (DIFF_OPT_TST(o, FUNCCONTEXT))
+		if (o->flags.funccontext)
 			xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
 		if (pe)
 			xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
@@ -3378,7 +3378,7 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
 	diff_free_filespec_data(one);
 	diff_free_filespec_data(two);
 	if (data.status)
-		DIFF_OPT_SET(o, CHECK_FAILED);
+		o->flags.check_failed = 1;
 }
 
 struct diff_filespec *alloc_filespec(const char *path)
@@ -3870,9 +3870,9 @@ static void fill_metainfo(struct strbuf *msg,
 		*must_show_header = 0;
 	}
 	if (one && two && oidcmp(&one->oid, &two->oid)) {
-		int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
+		int abbrev = o->flags.full_index ? 40 : DEFAULT_ABBREV;
 
-		if (DIFF_OPT_TST(o, BINARY)) {
+		if (o->flags.binary) {
 			mmfile_t mf;
 			if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
 			    (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
@@ -3902,7 +3902,7 @@ static void run_diff_cmd(const char *pgm,
 	int must_show_header = 0;
 
 
-	if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
+	if (o->flags.allow_external) {
 		struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
 		if (drv && drv->external)
 			pgm = drv->external;
@@ -3982,7 +3982,7 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
 	if (o->prefix_length)
 		strip_prefix(o->prefix_length, &name, &other);
 
-	if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
+	if (!o->flags.allow_external)
 		pgm = NULL;
 
 	if (DIFF_PAIR_UNMERGED(p)) {
@@ -4081,7 +4081,7 @@ void diff_setup(struct diff_options *options)
 	options->context = diff_context_default;
 	options->interhunkcontext = diff_interhunk_context_default;
 	options->ws_error_highlight = ws_error_highlight_default;
-	DIFF_OPT_SET(options, RENAME_EMPTY);
+	options->flags.rename_empty = 1;
 
 	/* pathchange left =NULL by default */
 	options->change = diff_change;
@@ -4132,14 +4132,14 @@ void diff_setup_done(struct diff_options *options)
 	if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
 	    DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
 	    DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
-		DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
+		options->flags.diff_from_contents = 1;
 	else
-		DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
+		options->flags.diff_from_contents = 0;
 
-	if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
+	if (options->flags.find_copies_harder)
 		options->detect_rename = DIFF_DETECT_COPY;
 
-	if (!DIFF_OPT_TST(options, RELATIVE_NAME))
+	if (!options->flags.relative_name)
 		options->prefix = NULL;
 	if (options->prefix)
 		options->prefix_length = strlen(options->prefix);
@@ -4169,18 +4169,18 @@ void diff_setup_done(struct diff_options *options)
 				      DIFF_FORMAT_DIRSTAT |
 				      DIFF_FORMAT_SUMMARY |
 				      DIFF_FORMAT_CHECKDIFF))
-		DIFF_OPT_SET(options, RECURSIVE);
+		options->flags.recursive = 1;
 	/*
 	 * Also pickaxe would not work very well if you do not say recursive
 	 */
 	if (options->pickaxe)
-		DIFF_OPT_SET(options, RECURSIVE);
+		options->flags.recursive = 1;
 	/*
 	 * When patches are generated, submodules diffed against the work tree
 	 * must be checked for dirtiness too so it can be shown in the output
 	 */
 	if (options->output_format & DIFF_FORMAT_PATCH)
-		DIFF_OPT_SET(options, DIRTY_SUBMODULES);
+		options->flags.dirty_submodules = 1;
 
 	if (options->detect_rename && options->rename_limit < 0)
 		options->rename_limit = diff_rename_limit_default;
@@ -4202,14 +4202,14 @@ void diff_setup_done(struct diff_options *options)
 	 * to have found.  It does not make sense not to return with
 	 * exit code in such a case either.
 	 */
-	if (DIFF_OPT_TST(options, QUICK)) {
+	if (options->flags.quick) {
 		options->output_format = DIFF_FORMAT_NO_OUTPUT;
-		DIFF_OPT_SET(options, EXIT_WITH_STATUS);
+		options->flags.exit_with_status = 1;
 	}
 
 	options->diff_path_counter = 0;
 
-	if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
+	if (options->flags.follow_renames && options->pathspec.nr != 1)
 		die(_("--follow requires exactly one pathspec"));
 
 	if (!options->use_color || external_diff())
@@ -4559,7 +4559,7 @@ int diff_opt_parse(struct diff_options *options,
 	else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
 		 !strcmp(arg, "--find-copies")) {
 		if (options->detect_rename == DIFF_DETECT_COPY)
-			DIFF_OPT_SET(options, FIND_COPIES_HARDER);
+			options->flags.find_copies_harder = 1;
 		if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
 			return error("invalid argument to -C: %s", arg+2);
 		options->detect_rename = DIFF_DETECT_COPY;
@@ -4567,13 +4567,13 @@ int diff_opt_parse(struct diff_options *options,
 	else if (!strcmp(arg, "--no-renames"))
 		options->detect_rename = 0;
 	else if (!strcmp(arg, "--rename-empty"))
-		DIFF_OPT_SET(options, RENAME_EMPTY);
+		options->flags.rename_empty = 1;
 	else if (!strcmp(arg, "--no-rename-empty"))
-		DIFF_OPT_CLR(options, RENAME_EMPTY);
+		options->flags.rename_empty = 0;
 	else if (!strcmp(arg, "--relative"))
-		DIFF_OPT_SET(options, RELATIVE_NAME);
+		options->flags.relative_name = 1;
 	else if (skip_prefix(arg, "--relative=", &arg)) {
-		DIFF_OPT_SET(options, RELATIVE_NAME);
+		options->flags.relative_name = 1;
 		options->prefix = arg;
 	}
 
@@ -4613,21 +4613,21 @@ int diff_opt_parse(struct diff_options *options,
 	/* flags options */
 	else if (!strcmp(arg, "--binary")) {
 		enable_patch_output(&options->output_format);
-		DIFF_OPT_SET(options, BINARY);
+		options->flags.binary = 1;
 	}
 	else if (!strcmp(arg, "--full-index"))
-		DIFF_OPT_SET(options, FULL_INDEX);
+		options->flags.full_index = 1;
 	else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
-		DIFF_OPT_SET(options, TEXT);
+		options->flags.text = 1;
 	else if (!strcmp(arg, "-R"))
-		DIFF_OPT_SET(options, REVERSE_DIFF);
+		options->flags.reverse_diff = 1;
 	else if (!strcmp(arg, "--find-copies-harder"))
-		DIFF_OPT_SET(options, FIND_COPIES_HARDER);
+		options->flags.find_copies_harder = 1;
 	else if (!strcmp(arg, "--follow"))
-		DIFF_OPT_SET(options, FOLLOW_RENAMES);
+		options->flags.follow_renames = 1;
 	else if (!strcmp(arg, "--no-follow")) {
-		DIFF_OPT_CLR(options, FOLLOW_RENAMES);
-		DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
+		options->flags.follow_renames = 0;
+		options->flags.default_follow_renames = 0;
 	} else if (!strcmp(arg, "--color"))
 		options->use_color = 1;
 	else if (skip_prefix(arg, "--color=", &arg)) {
@@ -4684,22 +4684,23 @@ int diff_opt_parse(struct diff_options *options,
 		return argcount;
 	}
 	else if (!strcmp(arg, "--exit-code"))
-		DIFF_OPT_SET(options, EXIT_WITH_STATUS);
+		options->flags.exit_with_status = 1;
 	else if (!strcmp(arg, "--quiet"))
-		DIFF_OPT_SET(options, QUICK);
+		options->flags.quick = 1;
 	else if (!strcmp(arg, "--ext-diff"))
-		DIFF_OPT_SET(options, ALLOW_EXTERNAL);
+		options->flags.allow_external = 1;
 	else if (!strcmp(arg, "--no-ext-diff"))
-		DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
-	else if (!strcmp(arg, "--textconv"))
-		DIFF_OPT_SET(options, ALLOW_TEXTCONV);
-	else if (!strcmp(arg, "--no-textconv"))
-		DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
+		options->flags.allow_external = 0;
+	else if (!strcmp(arg, "--textconv")) {
+		options->flags.allow_textconv = 1;
+		options->flags.textconv_set_via_cmdline = 1;
+	} else if (!strcmp(arg, "--no-textconv"))
+		options->flags.allow_textconv = 0;
 	else if (!strcmp(arg, "--ignore-submodules")) {
-		DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
+		options->flags.override_submodule_config = 1;
 		handle_ignore_submodules_arg(options, "all");
 	} else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
-		DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
+		options->flags.override_submodule_config = 1;
 		handle_ignore_submodules_arg(options, arg);
 	} else if (!strcmp(arg, "--submodule"))
 		options->submodule_format = DIFF_SUBMODULE_LOG;
@@ -4774,11 +4775,11 @@ int diff_opt_parse(struct diff_options *options,
 			 &options->interhunkcontext))
 		;
 	else if (!strcmp(arg, "-W"))
-		DIFF_OPT_SET(options, FUNCCONTEXT);
+		options->flags.funccontext = 1;
 	else if (!strcmp(arg, "--function-context"))
-		DIFF_OPT_SET(options, FUNCCONTEXT);
+		options->flags.funccontext = 1;
 	else if (!strcmp(arg, "--no-function-context"))
-		DIFF_OPT_CLR(options, FUNCCONTEXT);
+		options->flags.funccontext = 0;
 	else if ((argcount = parse_long_opt("output", av, &optarg))) {
 		char *path = prefix_filename(prefix, optarg);
 		options->file = xfopen(path, "w");
@@ -5528,7 +5529,7 @@ void diff_flush(struct diff_options *options)
 		separator++;
 	}
 
-	if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
+	if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
 		dirstat_by_line = 1;
 
 	if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
@@ -5563,8 +5564,8 @@ void diff_flush(struct diff_options *options)
 	}
 
 	if (output_format & DIFF_FORMAT_NO_OUTPUT &&
-	    DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
-	    DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
+	    options->flags.exit_with_status &&
+	    options->flags.diff_from_contents) {
 		/*
 		 * run diff_flush_patch for the exit status. setting
 		 * options->file to /dev/null should be safe, because we
@@ -5612,11 +5613,11 @@ free_queue:
 	 * diff_addremove/diff_change does not set the bit when
 	 * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
 	 */
-	if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
+	if (options->flags.diff_from_contents) {
 		if (options->found_changes)
-			DIFF_OPT_SET(options, HAS_CHANGES);
+			options->flags.has_changes = 1;
 		else
-			DIFF_OPT_CLR(options, HAS_CHANGES);
+			options->flags.has_changes = 0;
 	}
 }
 
@@ -5736,7 +5737,7 @@ static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
 			 * to determine how many paths were dirty only
 			 * due to stat info mismatch.
 			 */
-			if (!DIFF_OPT_TST(diffopt, NO_INDEX))
+			if (!diffopt->flags.no_index)
 				diffopt->skip_stat_unmatch++;
 			diff_free_filepair(p);
 		}
@@ -5785,10 +5786,10 @@ void diffcore_std(struct diff_options *options)
 		diff_resolve_rename_copy();
 	diffcore_apply_filter(options);
 
-	if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
-		DIFF_OPT_SET(options, HAS_CHANGES);
+	if (diff_queued_diff.nr && !options->flags.diff_from_contents)
+		options->flags.has_changes = 1;
 	else
-		DIFF_OPT_CLR(options, HAS_CHANGES);
+		options->flags.has_changes = 0;
 
 	options->found_follow = 0;
 }
@@ -5800,23 +5801,23 @@ int diff_result_code(struct diff_options *opt, int status)
 	diff_warn_rename_limit("diff.renameLimit",
 			       opt->needed_rename_limit,
 			       opt->degraded_cc_to_c);
-	if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
+	if (!opt->flags.exit_with_status &&
 	    !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
 		return status;
-	if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
-	    DIFF_OPT_TST(opt, HAS_CHANGES))
+	if (opt->flags.exit_with_status &&
+	    opt->flags.has_changes)
 		result |= 01;
 	if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
-	    DIFF_OPT_TST(opt, CHECK_FAILED))
+	    opt->flags.check_failed)
 		result |= 02;
 	return result;
 }
 
 int diff_can_quit_early(struct diff_options *opt)
 {
-	return (DIFF_OPT_TST(opt, QUICK) &&
+	return (opt->flags.quick &&
 		!opt->filter &&
-		DIFF_OPT_TST(opt, HAS_CHANGES));
+		opt->flags.has_changes);
 }
 
 /*
@@ -5828,10 +5829,10 @@ int diff_can_quit_early(struct diff_options *opt)
 static int is_submodule_ignored(const char *path, struct diff_options *options)
 {
 	int ignored = 0;
-	unsigned orig_flags = options->flags;
-	if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
+	struct diff_flags orig_flags = options->flags;
+	if (!options->flags.override_submodule_config)
 		set_diffopt_flags_from_submodule_config(options, path);
-	if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
+	if (options->flags.ignore_submodules)
 		ignored = 1;
 	options->flags = orig_flags;
 	return ignored;
@@ -5860,7 +5861,7 @@ void diff_addremove(struct diff_options *options,
 	 * Before the final output happens, they are pruned after
 	 * merged into rename/copy pairs as appropriate.
 	 */
-	if (DIFF_OPT_TST(options, REVERSE_DIFF))
+	if (options->flags.reverse_diff)
 		addremove = (addremove == '+' ? '-' :
 			     addremove == '-' ? '+' : addremove);
 
@@ -5879,8 +5880,8 @@ void diff_addremove(struct diff_options *options,
 	}
 
 	diff_queue(&diff_queued_diff, one, two);
-	if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
-		DIFF_OPT_SET(options, HAS_CHANGES);
+	if (!options->flags.diff_from_contents)
+		options->flags.has_changes = 1;
 }
 
 void diff_change(struct diff_options *options,
@@ -5898,7 +5899,7 @@ void diff_change(struct diff_options *options,
 	    is_submodule_ignored(concatpath, options))
 		return;
 
-	if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
+	if (options->flags.reverse_diff) {
 		SWAP(old_mode, new_mode);
 		SWAP(old_oid, new_oid);
 		SWAP(old_oid_valid, new_oid_valid);
@@ -5917,14 +5918,14 @@ void diff_change(struct diff_options *options,
 	two->dirty_submodule = new_dirty_submodule;
 	p = diff_queue(&diff_queued_diff, one, two);
 
-	if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
+	if (options->flags.diff_from_contents)
 		return;
 
-	if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
+	if (options->flags.quick && options->skip_stat_unmatch &&
 	    !diff_filespec_check_stat_unmatch(p))
 		return;
 
-	DIFF_OPT_SET(options, HAS_CHANGES);
+	options->flags.has_changes = 1;
 }
 
 struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
@@ -6062,7 +6063,7 @@ void setup_diff_pager(struct diff_options *opt)
 	 * and because it is easy to find people oneline advising "git diff
 	 * --exit-code" in hooks and other scripts, we do not do so.
 	 */
-	if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
+	if (!opt->flags.exit_with_status &&
 	    check_pager_config("diff") != 0)
 		setup_pager();
 }
diff --git a/diff.h b/diff.h
index 398b87b4cf..0fb18dd735 100644
--- a/diff.h
+++ b/diff.h
@@ -60,42 +60,52 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
 
 #define DIFF_FORMAT_CALLBACK	0x1000
 
-#define DIFF_OPT_RECURSIVE           (1 <<  0)
-#define DIFF_OPT_TREE_IN_RECURSIVE   (1 <<  1)
-#define DIFF_OPT_BINARY              (1 <<  2)
-#define DIFF_OPT_TEXT                (1 <<  3)
-#define DIFF_OPT_FULL_INDEX          (1 <<  4)
-#define DIFF_OPT_SILENT_ON_REMOVE    (1 <<  5)
-#define DIFF_OPT_FIND_COPIES_HARDER  (1 <<  6)
-#define DIFF_OPT_FOLLOW_RENAMES      (1 <<  7)
-#define DIFF_OPT_RENAME_EMPTY        (1 <<  8)
-/* (1 <<  9) unused */
-#define DIFF_OPT_HAS_CHANGES         (1 << 10)
-#define DIFF_OPT_QUICK               (1 << 11)
-#define DIFF_OPT_NO_INDEX            (1 << 12)
-#define DIFF_OPT_ALLOW_EXTERNAL      (1 << 13)
-#define DIFF_OPT_EXIT_WITH_STATUS    (1 << 14)
-#define DIFF_OPT_REVERSE_DIFF        (1 << 15)
-#define DIFF_OPT_CHECK_FAILED        (1 << 16)
-#define DIFF_OPT_RELATIVE_NAME       (1 << 17)
-#define DIFF_OPT_IGNORE_SUBMODULES   (1 << 18)
-#define DIFF_OPT_DIRSTAT_CUMULATIVE  (1 << 19)
-#define DIFF_OPT_DIRSTAT_BY_FILE     (1 << 20)
-#define DIFF_OPT_ALLOW_TEXTCONV      (1 << 21)
-#define DIFF_OPT_DIFF_FROM_CONTENTS  (1 << 22)
-#define DIFF_OPT_DIRTY_SUBMODULES    (1 << 24)
-#define DIFF_OPT_IGNORE_UNTRACKED_IN_SUBMODULES (1 << 25)
-#define DIFF_OPT_IGNORE_DIRTY_SUBMODULES (1 << 26)
-#define DIFF_OPT_OVERRIDE_SUBMODULE_CONFIG (1 << 27)
-#define DIFF_OPT_DIRSTAT_BY_LINE     (1 << 28)
-#define DIFF_OPT_FUNCCONTEXT         (1 << 29)
-#define DIFF_OPT_PICKAXE_IGNORE_CASE (1 << 30)
-#define DIFF_OPT_DEFAULT_FOLLOW_RENAMES (1U << 31)
+#define DIFF_FLAGS_INIT { 0 }
+struct diff_flags {
+	unsigned recursive:1;
+	unsigned tree_in_recursive:1;
+	unsigned binary:1;
+	unsigned text:1;
+	unsigned full_index:1;
+	unsigned silent_on_remove:1;
+	unsigned find_copies_harder:1;
+	unsigned follow_renames:1;
+	unsigned rename_empty:1;
+	unsigned has_changes:1;
+	unsigned quick:1;
+	unsigned no_index:1;
+	unsigned allow_external:1;
+	unsigned exit_with_status:1;
+	unsigned reverse_diff:1;
+	unsigned check_failed:1;
+	unsigned relative_name:1;
+	unsigned ignore_submodules:1;
+	unsigned dirstat_cumulative:1;
+	unsigned dirstat_by_file:1;
+	unsigned allow_textconv:1;
+	unsigned textconv_set_via_cmdline:1;
+	unsigned diff_from_contents:1;
+	unsigned dirty_submodules:1;
+	unsigned ignore_untracked_in_submodules:1;
+	unsigned ignore_dirty_submodules:1;
+	unsigned override_submodule_config:1;
+	unsigned dirstat_by_line:1;
+	unsigned funccontext:1;
+	unsigned pickaxe_ignore_case:1;
+	unsigned default_follow_renames:1;
+};
+
+static inline void diff_flags_or(struct diff_flags *a,
+				 const struct diff_flags *b)
+{
+	char *tmp_a = (char *)a;
+	const char *tmp_b = (const char *)b;
+	int i;
+
+	for (i = 0; i < sizeof(struct diff_flags); i++)
+		tmp_a[i] |= tmp_b[i];
+}
 
-#define DIFF_OPT_TST(opts, flag)    ((opts)->flags & DIFF_OPT_##flag)
-#define DIFF_OPT_TOUCHED(opts, flag)    ((opts)->touched_flags & DIFF_OPT_##flag)
-#define DIFF_OPT_SET(opts, flag)    (((opts)->flags |= DIFF_OPT_##flag),((opts)->touched_flags |= DIFF_OPT_##flag))
-#define DIFF_OPT_CLR(opts, flag)    (((opts)->flags &= ~DIFF_OPT_##flag),((opts)->touched_flags |= DIFF_OPT_##flag))
 #define DIFF_XDL_TST(opts, flag)    ((opts)->xdl_opts & XDF_##flag)
 #define DIFF_XDL_SET(opts, flag)    ((opts)->xdl_opts |= XDF_##flag)
 #define DIFF_XDL_CLR(opts, flag)    ((opts)->xdl_opts &= ~XDF_##flag)
@@ -122,8 +132,7 @@ struct diff_options {
 	const char *a_prefix, *b_prefix;
 	const char *line_prefix;
 	size_t line_prefix_length;
-	unsigned flags;
-	unsigned touched_flags;
+	struct diff_flags flags;
 
 	/* diff-filter bits */
 	unsigned int filter;
@@ -389,7 +398,8 @@ extern int diff_result_code(struct diff_options *, int);
 
 extern void diff_no_index(struct rev_info *, int, const char **);
 
-extern int index_differs_from(const char *def, int diff_flags, int ita_invisible_in_index);
+extern int index_differs_from(const char *def, const struct diff_flags *flags,
+			      int ita_invisible_in_index);
 
 /*
  * Fill the contents of the filespec "df", respecting any textconv defined by
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index 341529b5a8..9476bd2108 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c
@@ -131,7 +131,7 @@ static int pickaxe_match(struct diff_filepair *p, struct diff_options *o,
 	if (!DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two))
 		return 0;
 
-	if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
+	if (o->flags.allow_textconv) {
 		textconv_one = get_textconv(p->one);
 		textconv_two = get_textconv(p->two);
 	}
@@ -222,11 +222,11 @@ void diffcore_pickaxe(struct diff_options *o)
 
 	if (opts & (DIFF_PICKAXE_REGEX | DIFF_PICKAXE_KIND_G)) {
 		int cflags = REG_EXTENDED | REG_NEWLINE;
-		if (DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE))
+		if (o->flags.pickaxe_ignore_case)
 			cflags |= REG_ICASE;
 		regcomp_or_die(&regex, needle, cflags);
 		regexp = &regex;
-	} else if (DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE) &&
+	} else if (o->flags.pickaxe_ignore_case &&
 		   has_non_ascii(needle)) {
 		struct strbuf sb = STRBUF_INIT;
 		int cflags = REG_NEWLINE | REG_ICASE;
@@ -236,7 +236,7 @@ void diffcore_pickaxe(struct diff_options *o)
 		strbuf_release(&sb);
 		regexp = &regex;
 	} else {
-		kws = kwsalloc(DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE)
+		kws = kwsalloc(o->flags.pickaxe_ignore_case
 			       ? tolower_trans_tbl : NULL);
 		kwsincr(kws, needle, strlen(needle));
 		kwsprep(kws);
diff --git a/diffcore-rename.c b/diffcore-rename.c
index 0d8c3d2ee4..12dc2a056f 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -405,7 +405,7 @@ static int too_many_rename_candidates(int num_create,
 		num_src > num_create ? num_src : num_create;
 
 	/* Are we running under -C -C? */
-	if (!DIFF_OPT_TST(options, FIND_COPIES_HARDER))
+	if (!options->flags.find_copies_harder)
 		return 1;
 
 	/* Would we bust the limit if we were running under -C? */
@@ -463,7 +463,7 @@ void diffcore_rename(struct diff_options *options)
 			else if (options->single_follow &&
 				 strcmp(options->single_follow, p->two->path))
 				continue; /* not interested */
-			else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
+			else if (!options->flags.rename_empty &&
 				 is_empty_blob_oid(&p->two->oid))
 				continue;
 			else if (add_rename_dst(p->two) < 0) {
@@ -473,7 +473,7 @@ void diffcore_rename(struct diff_options *options)
 				goto cleanup;
 			}
 		}
-		else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
+		else if (!options->flags.rename_empty &&
 			 is_empty_blob_oid(&p->one->oid))
 			continue;
 		else if (!DIFF_PAIR_UNMERGED(p) && !DIFF_FILE_VALID(p->two)) {
diff --git a/log-tree.c b/log-tree.c
index 580b3a98a0..3b904f0375 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -793,7 +793,7 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log
 	struct commit_list *parents;
 	struct object_id *oid;
 
-	if (!opt->diff && !DIFF_OPT_TST(&opt->diffopt, EXIT_WITH_STATUS))
+	if (!opt->diff && !opt->diffopt.flags.exit_with_status)
 		return 0;
 
 	parse_commit_or_die(commit);
diff --git a/merge-recursive.c b/merge-recursive.c
index 24c5c26a6a..2ca8444c65 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -540,8 +540,8 @@ static struct string_list *get_renames(struct merge_options *o,
 		return renames;
 
 	diff_setup(&opts);
-	DIFF_OPT_SET(&opts, RECURSIVE);
-	DIFF_OPT_CLR(&opts, RENAME_EMPTY);
+	opts.flags.recursive = 1;
+	opts.flags.rename_empty = 0;
 	opts.detect_rename = DIFF_DETECT_RENAME;
 	opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 			    o->diff_rename_limit >= 0 ? o->diff_rename_limit :
diff --git a/notes-merge.c b/notes-merge.c
index 30ec83ab04..4a83b0ebd5 100644
--- a/notes-merge.c
+++ b/notes-merge.c
@@ -125,7 +125,7 @@ static struct notes_merge_pair *diff_tree_remote(struct notes_merge_options *o,
 	       oid_to_hex(base), oid_to_hex(remote));
 
 	diff_setup(&opt);
-	DIFF_OPT_SET(&opt, RECURSIVE);
+	opt.flags.recursive = 1;
 	opt.output_format = DIFF_FORMAT_NO_OUTPUT;
 	diff_setup_done(&opt);
 	diff_tree_oid(base, remote, "", &opt);
@@ -188,7 +188,7 @@ static void diff_tree_local(struct notes_merge_options *o,
 	       len, oid_to_hex(base), oid_to_hex(local));
 
 	diff_setup(&opt);
-	DIFF_OPT_SET(&opt, RECURSIVE);
+	opt.flags.recursive = 1;
 	opt.output_format = DIFF_FORMAT_NO_OUTPUT;
 	diff_setup_done(&opt);
 	diff_tree_oid(base, local, "", &opt);
diff --git a/patch-ids.c b/patch-ids.c
index 7a583b3011..8f7c25d5db 100644
--- a/patch-ids.c
+++ b/patch-ids.c
@@ -61,7 +61,7 @@ int init_patch_ids(struct patch_ids *ids)
 	memset(ids, 0, sizeof(*ids));
 	diff_setup(&ids->diffopts);
 	ids->diffopts.detect_rename = 0;
-	DIFF_OPT_SET(&ids->diffopts, RECURSIVE);
+	ids->diffopts.flags.recursive = 1;
 	diff_setup_done(&ids->diffopts);
 	hashmap_init(&ids->patches, patch_id_cmp, &ids->diffopts, 256);
 	return 0;
diff --git a/revision.c b/revision.c
index 99c95c19b0..e2e691dd5a 100644
--- a/revision.c
+++ b/revision.c
@@ -419,7 +419,7 @@ static void file_add_remove(struct diff_options *options,
 
 	tree_difference |= diff;
 	if (!revs->remove_empty_trees || tree_difference != REV_TREE_NEW)
-		DIFF_OPT_SET(options, HAS_CHANGES);
+		options->flags.has_changes = 1;
 }
 
 static void file_change(struct diff_options *options,
@@ -431,7 +431,7 @@ static void file_change(struct diff_options *options,
 		 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 {
 	tree_difference = REV_TREE_DIFFERENT;
-	DIFF_OPT_SET(options, HAS_CHANGES);
+	options->flags.has_changes = 1;
 }
 
 static int rev_compare_tree(struct rev_info *revs,
@@ -464,7 +464,7 @@ static int rev_compare_tree(struct rev_info *revs,
 	}
 
 	tree_difference = REV_TREE_SAME;
-	DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
+	revs->pruning.flags.has_changes = 0;
 	if (diff_tree_oid(&t1->object.oid, &t2->object.oid, "",
 			   &revs->pruning) < 0)
 		return REV_TREE_DIFFERENT;
@@ -480,7 +480,7 @@ static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 		return 0;
 
 	tree_difference = REV_TREE_SAME;
-	DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
+	revs->pruning.flags.has_changes = 0;
 	retval = diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);
 
 	return retval >= 0 && (tree_difference == REV_TREE_SAME);
@@ -1412,8 +1412,8 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	revs->abbrev = DEFAULT_ABBREV;
 	revs->ignore_merges = 1;
 	revs->simplify_history = 1;
-	DIFF_OPT_SET(&revs->pruning, RECURSIVE);
-	DIFF_OPT_SET(&revs->pruning, QUICK);
+	revs->pruning.flags.recursive = 1;
+	revs->pruning.flags.quick = 1;
 	revs->pruning.add_remove = file_add_remove;
 	revs->pruning.change = file_change;
 	revs->pruning.change_fn_data = revs;
@@ -1927,11 +1927,11 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		die("--unpacked=<packfile> no longer supported.");
 	} else if (!strcmp(arg, "-r")) {
 		revs->diff = 1;
-		DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
+		revs->diffopt.flags.recursive = 1;
 	} else if (!strcmp(arg, "-t")) {
 		revs->diff = 1;
-		DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
-		DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
+		revs->diffopt.flags.recursive = 1;
+		revs->diffopt.flags.tree_in_recursive = 1;
 	} else if (!strcmp(arg, "-m")) {
 		revs->ignore_merges = 0;
 	} else if (!strcmp(arg, "-c")) {
@@ -2076,7 +2076,7 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
 	} else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
 		revs->grep_filter.ignore_case = 1;
-		DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
+		revs->diffopt.flags.pickaxe_ignore_case = 1;
 	} else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
 		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
 	} else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
@@ -2409,7 +2409,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 	/* Pickaxe, diff-filter and rename following need diffs */
 	if (revs->diffopt.pickaxe ||
 	    revs->diffopt.filter ||
-	    DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
+	    revs->diffopt.flags.follow_renames)
 		revs->diff = 1;
 
 	if (revs->topo_order)
@@ -2418,7 +2418,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 	if (revs->prune_data.nr) {
 		copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
 		/* Can't prune commits with rename following: the paths change.. */
-		if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
+		if (!revs->diffopt.flags.follow_renames)
 			revs->prune = 1;
 		if (!revs->full_diff)
 			copy_pathspec(&revs->diffopt.pathspec,
diff --git a/sequencer.c b/sequencer.c
index 1eb2c4669d..6d027b06c8 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -959,7 +959,8 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 		unborn = get_oid("HEAD", &head);
 		if (unborn)
 			oidcpy(&head, &empty_tree_oid);
-		if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0, 0))
+		if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD",
+				       NULL, 0))
 			return error_dirty_index(opts);
 	}
 	discard_cache();
@@ -2283,7 +2284,7 @@ int sequencer_continue(struct replay_opts *opts)
 			if (res)
 				goto release_todo_list;
 		}
-		if (index_differs_from("HEAD", 0, 0)) {
+		if (index_differs_from("HEAD", NULL, 0)) {
 			res = error_dirty_index(opts);
 			goto release_todo_list;
 		}
diff --git a/submodule.c b/submodule.c
index 239d94d539..3ee4a0caa7 100644
--- a/submodule.c
+++ b/submodule.c
@@ -183,7 +183,7 @@ void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 		if (ignore)
 			handle_ignore_submodules_arg(diffopt, ignore);
 		else if (is_gitmodules_unmerged(&the_index))
-			DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
+			diffopt->flags.ignore_submodules = 1;
 	}
 }
 
@@ -402,16 +402,16 @@ const char *submodule_strategy_to_string(const struct submodule_update_strategy
 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 				  const char *arg)
 {
-	DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
-	DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
-	DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
+	diffopt->flags.ignore_submodules = 0;
+	diffopt->flags.ignore_untracked_in_submodules = 0;
+	diffopt->flags.ignore_dirty_submodules = 0;
 
 	if (!strcmp(arg, "all"))
-		DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
+		diffopt->flags.ignore_submodules = 1;
 	else if (!strcmp(arg, "untracked"))
-		DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
+		diffopt->flags.ignore_untracked_in_submodules = 1;
 	else if (!strcmp(arg, "dirty"))
-		DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
+		diffopt->flags.ignore_dirty_submodules = 1;
 	else if (strcmp(arg, "none"))
 		die("bad --ignore-submodules argument: %s", arg);
 }
@@ -616,7 +616,7 @@ void show_submodule_inline_diff(struct diff_options *o, const char *path,
 	argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 			 "always" : "never");
 
-	if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
+	if (o->flags.reverse_diff) {
 		argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 				 o->b_prefix, path);
 		argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
diff --git a/tree-diff.c b/tree-diff.c
index 4bb93155bc..fe2e466ac1 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -212,9 +212,9 @@ static struct combine_diff_path *emit_path(struct combine_diff_path *p,
 		mode = 0;
 	}
 
-	if (DIFF_OPT_TST(opt, RECURSIVE) && isdir) {
+	if (opt->flags.recursive && isdir) {
 		recurse = 1;
-		emitthis = DIFF_OPT_TST(opt, TREE_IN_RECURSIVE);
+		emitthis = opt->flags.tree_in_recursive;
 	}
 
 	if (emitthis) {
@@ -425,7 +425,7 @@ static struct combine_diff_path *ll_diff_tree_paths(
 	ttree = fill_tree_descriptor(&t, oid);
 
 	/* Enable recursion indefinitely */
-	opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);
+	opt->pathspec.recursive = opt->flags.recursive;
 
 	for (;;) {
 		int imin, cmp;
@@ -484,7 +484,7 @@ static struct combine_diff_path *ll_diff_tree_paths(
 		/* t = p[imin] */
 		if (cmp == 0) {
 			/* are either pi > p[imin] or diff(t,pi) != ø ? */
-			if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER)) {
+			if (!opt->flags.find_copies_harder) {
 				for (i = 0; i < nparent; ++i) {
 					/* p[i] > p[imin] */
 					if (tp[i].entry.mode & S_IFXMIN_NEQ)
@@ -522,7 +522,7 @@ static struct combine_diff_path *ll_diff_tree_paths(
 		/* t > p[imin] */
 		else {
 			/* ∀i pi=p[imin] -> D += "-p[imin]" */
-			if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER)) {
+			if (!opt->flags.find_copies_harder) {
 				for (i = 0; i < nparent; ++i)
 					if (tp[i].entry.mode & S_IFXMIN_NEQ)
 						goto skip_emit_tp;
@@ -608,8 +608,8 @@ static void try_to_follow_renames(const struct object_id *old_oid,
 	q->nr = 0;
 
 	diff_setup(&diff_opts);
-	DIFF_OPT_SET(&diff_opts, RECURSIVE);
-	DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
+	diff_opts.flags.recursive = 1;
+	diff_opts.flags.find_copies_harder = 1;
 	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 	diff_opts.single_follow = opt->pathspec.items[0].match;
 	diff_opts.break_opt = opt->break_opt;
@@ -706,7 +706,7 @@ int diff_tree_oid(const struct object_id *old_oid,
 	strbuf_addstr(&base, base_str);
 
 	retval = ll_diff_tree_oid(old_oid, new_oid, &base, opt);
-	if (!*base_str && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename())
+	if (!*base_str && opt->flags.follow_renames && diff_might_be_rename())
 		try_to_follow_renames(old_oid, new_oid, &base, opt);
 
 	strbuf_release(&base);
diff --git a/wt-status.c b/wt-status.c
index bedef256ce..ed3271c3f3 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -559,12 +559,12 @@ static void wt_status_collect_changes_worktree(struct wt_status *s)
 	init_revisions(&rev, NULL);
 	setup_revisions(0, NULL, &rev, NULL);
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
-	DIFF_OPT_SET(&rev.diffopt, DIRTY_SUBMODULES);
+	rev.diffopt.flags.dirty_submodules = 1;
 	rev.diffopt.ita_invisible_in_index = 1;
 	if (!s->show_untracked_files)
-		DIFF_OPT_SET(&rev.diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
+		rev.diffopt.flags.ignore_untracked_in_submodules = 1;
 	if (s->ignore_submodule_arg) {
-		DIFF_OPT_SET(&rev.diffopt, OVERRIDE_SUBMODULE_CONFIG);
+		rev.diffopt.flags.override_submodule_config = 1;
 		handle_ignore_submodules_arg(&rev.diffopt, s->ignore_submodule_arg);
 	}
 	rev.diffopt.format_callback = wt_status_collect_changed_cb;
@@ -583,7 +583,7 @@ static void wt_status_collect_changes_index(struct wt_status *s)
 	opt.def = s->is_initial ? EMPTY_TREE_SHA1_HEX : s->reference;
 	setup_revisions(0, NULL, &rev, &opt);
 
-	DIFF_OPT_SET(&rev.diffopt, OVERRIDE_SUBMODULE_CONFIG);
+	rev.diffopt.flags.override_submodule_config = 1;
 	rev.diffopt.ita_invisible_in_index = 1;
 	if (s->ignore_submodule_arg) {
 		handle_ignore_submodules_arg(&rev.diffopt, s->ignore_submodule_arg);
@@ -949,7 +949,7 @@ static void wt_longstatus_print_verbose(struct wt_status *s)
 	const char *c = color(WT_STATUS_HEADER, s);
 
 	init_revisions(&rev, NULL);
-	DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
+	rev.diffopt.flags.allow_textconv = 1;
 	rev.diffopt.ita_invisible_in_index = 1;
 
 	memset(&opt, 0, sizeof(opt));
@@ -2263,8 +2263,8 @@ int has_unstaged_changes(int ignore_submodules)
 
 	init_revisions(&rev_info, NULL);
 	if (ignore_submodules)
-		DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES);
-	DIFF_OPT_SET(&rev_info.diffopt, QUICK);
+		rev_info.diffopt.flags.ignore_submodules = 1;
+	rev_info.diffopt.flags.quick = 1;
 	diff_setup_done(&rev_info.diffopt);
 	result = run_diff_files(&rev_info, 0);
 	return diff_result_code(&rev_info.diffopt, result);
@@ -2283,8 +2283,8 @@ int has_uncommitted_changes(int ignore_submodules)
 
 	init_revisions(&rev_info, NULL);
 	if (ignore_submodules)
-		DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES);
-	DIFF_OPT_SET(&rev_info.diffopt, QUICK);
+		rev_info.diffopt.flags.ignore_submodules = 1;
+	rev_info.diffopt.flags.quick = 1;
 	add_head_to_pending(&rev_info);
 	diff_setup_done(&rev_info.diffopt);
 	result = run_diff_index(&rev_info, 1);