[RFC_PATCHv4 3/7] submodule-config: add method to check for being labeled

[Stefan Beller <sbeller@google.com>]

In later patches we need to tell if a submodule is labeled by
the given labels.

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 submodule-config.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 submodule-config.h |  3 +++
 2 files changed, 51 insertions(+)

diff --git a/submodule-config.c b/submodule-config.c
index 7b48e59..b10a773 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -493,3 +493,51 @@ void submodule_free(void)
 	cache_free(&cache);
 	is_cache_init = 0;
 }
+
+int submodule_applicable_by_labels(const struct string_list *list,
+				   const struct submodule *sub)
+{
+	int label_apply = 0;
+	struct strbuf sb = STRBUF_INIT;
+
+	if (!list)
+		return 1;
+
+	if (sub->labels) {
+		struct string_list_item *item;
+		for_each_string_list_item(item, sub->labels) {
+			strbuf_reset(&sb);
+			strbuf_addf(&sb, "*%s", item->string);
+			if (string_list_has_string(list, sb.buf)) {
+				label_apply = 1;
+				break;
+			}
+		}
+	}
+	if (sub->path) {
+		/*
+		 * NEEDSWORK: This currently works only for
+		 * exact paths, but we want to enable
+		 * inexact matches such wildcards.
+		 */
+		strbuf_reset(&sb);
+		strbuf_addf(&sb, "./%s", sub->path);
+		if (string_list_has_string(list, sb.buf)) {
+			label_apply = 1;
+		}
+	}
+	if (sub->name) {
+		/*
+		 * NEEDSWORK: Same as with path. Do we want to
+		 * support wildcards or such?
+		 */
+		strbuf_reset(&sb);
+		strbuf_addf(&sb, ":%s", sub->name);
+		if (string_list_has_string(list, sb.buf)) {
+			label_apply = 1;
+		}
+	}
+	strbuf_release(&sb);
+
+	return label_apply;
+}
diff --git a/submodule-config.h b/submodule-config.h
index 8d61df3..d67f666 100644
--- a/submodule-config.h
+++ b/submodule-config.h
@@ -30,4 +30,7 @@ const struct submodule *submodule_from_path(const unsigned char *commit_sha1,
 		const char *path);
 void submodule_free(void);
 
+int submodule_applicable_by_labels(const struct string_list *list,
+				   const struct submodule *sub);
+
 #endif /* SUBMODULE_CONFIG_H */
-- 
2.7.0.rc0.45.g6b4c145