From a6d795bac5fa0ea1bac8c89925670f6e20fd3c01 Mon Sep 17 00:00:00 2001
From: Alejandro Colomar <alx@kernel.org>
Date: Fri, 1 Sep 2023 18:57:41 +0200
Subject: [PATCH] autogen.sh: CFLAGS: Add -Werror=implicit-function-declaration

This is not just a style issue.  This should be a hard error, and never
compile.  ISO C89 already had this feature as deprecated.  ISO C99
removed this deprecated feature, for good reasons.  If we compile
ignoring this warning, shadow is not going to behave well.

Cc: Sam James <sam@gentoo.org>
Reviewed-by: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 autogen.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/autogen.sh b/autogen.sh
index 881e9770..eb30a9a1 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -3,7 +3,7 @@
 autoreconf -v -f --install "$(dirname "$0")" || exit 1
 
 "$(dirname "$0")"/configure \
-	CFLAGS="-O2 -Wall" \
+	CFLAGS="-O2 -Wall -Werror=implicit-function-declaration" \
 	--enable-lastlog \
 	--enable-man \
 	--enable-maintainer-mode \