From 127ccb37251744c0fad2df0f3f67dd2c38fe8389 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Sun, 22 Dec 2019 23:20:00 +0100
Subject: [PATCH] Fix compiler warning for ppoll() on Cygwin

_GNU_SOURCE is required to get the prototype, so just define that
globally, as was already done in the linux template.

Discussion: https://www.postgresql.org/message-id/flat/6b467edc-4018-521f-ab18-171f098557ca%402ndquadrant.com
---
 src/template/cygwin | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/template/cygwin b/src/template/cygwin
index 79a108145f..1e7274bc33 100644
--- a/src/template/cygwin
+++ b/src/template/cygwin
@@ -2,6 +2,9 @@
 
 SRCH_LIB="/usr/local/lib"
 
+# This is required for ppoll(2), and perhaps other things
+CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"
+
 # Extra CFLAGS for code that will go into a shared library
 CFLAGS_SL=""