til: introduce til_value_to_pos() helper

This copies from checkers_value_to_pos() turning it into a libtil
helper.  It's a common operation in setup_funcs to map a setting
value to a numeric position in the list of values.

2 files changed, 22 insertions, 0 deletions

diff --git a/src/til.c b/src/til.c
index 8fa3b48..2ebc0a8 100644
--- a/src/til.c
+++ b/src/til.c
@@ -669,3 +669,24 @@ int til_fragmenter_tile64(til_module_context_t *context, const til_fb_fragment_t
 {
 	return til_fb_fragment_tile_single(fragment, 64, number, res_fragment);
 }
+
+
+/* Helper for mapping a value to a position in the supplied NULL-terminated lsit of options.
+ * Primarily useful for modules when mapping a settings value to an entry in a values array.
+ * Returns 0 on success w/position @res_pos, -ENOENT when not found.
+ */
+int til_value_to_pos(const char **options, const char *value, unsigned *res_pos)
+{
+	assert(options);
+	assert(value);
+	assert(res_pos);
+
+	for (unsigned i = 0; options[i]; i++) {
+		if (!strcasecmp(value, options[i])) {
+			*res_pos = i;
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
diff --git a/src/til.h b/src/til.h
index 9fb8b5b..9049a0b 100644
--- a/src/til.h
+++ b/src/til.h
@@ -58,5 +58,6 @@ int til_fragmenter_noop_per_cpu(til_module_context_t *context, const til_fb_frag
 int til_fragmenter_slice_per_cpu(til_module_context_t *context, const til_fb_fragment_t *fragment, unsigned number, til_fb_fragment_t *res_fragment);
 int til_fragmenter_slice_per_cpu_x16(til_module_context_t *context, const til_fb_fragment_t *fragment, unsigned number, til_fb_fragment_t *res_fragment);
 int til_fragmenter_tile64(til_module_context_t *context, const til_fb_fragment_t *fragment, unsigned number, til_fb_fragment_t *res_fragment);
+int til_value_to_pos(const char **options, const char *value, unsigned *res_pos);
 
 #endif