From 04cf2038e906009d4e2ae2e39eb45bdc27dfe12a Mon Sep 17 00:00:00 2001
From: Tim Stahlhut <stahta01@gmail.com>
Date: Fri, 2 Aug 2019 11:36:47 -0400
Subject: [PATCH] Ensure visibility of needed Cygwin declarations

Dl_info requires __GNU_VISIBLE be defined; and,
pthread_setconcurrency requires  __XSI_VISIBLE >= 500.
Defining _GNU_SOURCE satifies both of the above needs.
---
 include/wx/platform.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/wx/platform.h b/include/wx/platform.h
index 47c1c4778c..91749a1c8b 100644
--- a/include/wx/platform.h
+++ b/include/wx/platform.h
@@ -280,6 +280,11 @@
 #    if defined(__INNOTEK_LIBC__)
         /* Ensure visibility of strnlen declaration */
 #        define _GNU_SOURCE
+#    endif
+
+#    if defined(__CYGWIN__)
+        /* Ensure visibility of Dl_info and pthread_setconcurrency declarations */
+#        define _GNU_SOURCE
 #    endif
 
     /* define __HPUX__ for HP-UX where standard macro is __hpux */