From 2282f51b5e886d744ce9d9a538e11df0c3aa4b59 Mon Sep 17 00:00:00 2001
From: Soutaro Matsumoto <matsumoto@soutaro.com>
Date: Thu, 6 Jun 2024 18:01:17 +0900
Subject: [PATCH] Make c99, c23 compatible

---
 ext/rbs_extension/location.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/ext/rbs_extension/location.h b/ext/rbs_extension/location.h
index 63b926e55..b8d1ddf14 100644
--- a/ext/rbs_extension/location.h
+++ b/ext/rbs_extension/location.h
@@ -16,17 +16,19 @@ typedef struct {
 
 typedef unsigned int rbs_loc_entry_bitmap;
 
+// The flexible array always allocates, but it's okay.
+// This struct is not allocated when the `rbs_loc` doesn't have children.
 typedef struct {
   unsigned short len;
   unsigned short cap;
   rbs_loc_entry_bitmap required_p;
-  rbs_loc_entry entries[0];
+  rbs_loc_entry entries[1];
 } rbs_loc_children;
 
 typedef struct {
   VALUE buffer;
   range rg;
-  rbs_loc_children *children;
+  rbs_loc_children *children; // NULL when no children is allocated
 } rbs_loc;
 
 /**