From 739e441d4d4135e411e94a6e4c190a7fa32ac400 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Claes=20N=C3=A4st=C3=A9n?= <pekdon@gmail.com>
Date: Tue, 15 Mar 2022 13:51:00 +0100
Subject: [PATCH] build: AC_SUBST for AM_CFLAGS (#3551)

Using autoconf 2.71 and automake 1.16.5 the CFLAGS from
CC_CHECK_CFLAGS_APPEND does not get set in the Makefile without AC_SUBST
causing compilation to fail on Solaris due to missing -std=gnu89
---
 m4/libuv-check-flags.m4 | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/m4/libuv-check-flags.m4 b/m4/libuv-check-flags.m4
index 46b9dd86a..9d0aad82a 100644
--- a/m4/libuv-check-flags.m4
+++ b/m4/libuv-check-flags.m4
@@ -73,6 +73,8 @@ AC_DEFUN([CC_CHECK_CFLAG_APPEND], [
 
   AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
     [AM_CFLAGS="$AM_CFLAGS $1"; DEBUG_CFLAGS="$DEBUG_CFLAGS $1"; $2], [$3])
+
+  AC_SUBST([AM_CFLAGS])
 ])
 
 dnl CC_CHECK_CFLAGS_APPEND([FLAG1 FLAG2], [action-if-found], [action-if-not])