From 48bb0329eb325bc5b77c222f45b8dc97a208d986 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Sun, 13 Dec 2020 00:03:06 +0900
Subject: [PATCH] Revert AC_PROG_CC_C99 for -std=gnu99 option to gcc 4.8

---
 configure.ac | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index cd0c9e6ec0..5aaecbaa0a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -168,7 +168,10 @@ rb_test_CFLAGS=${CFLAGS+yes}
 rb_test_CXXFLAGS=${CXXFLAGS+yes}
 
 # BSD's ports and MacPorts prefix GNU binutils with 'g'
-# AC_PROG_CC_C99
+
+dnl Seems necessarily in order to add -std=gnu99 option for gcc 4.9.
+m4_version_prereq([2.70], [], [AC_PROG_CC_C99])
+
 AC_PROG_CXX
 AC_PROG_CPP
 AC_PROG_RANLIB