[glib: 3/6] meson: Only look for _NSGetEnviron when building for macOS

[Sebastian Dröge <sdroege src gnome org>]

commit a28b52d7db5f60e96c7c7f5ff0c42e9661e5e32a
Author: Nirbheek Chauhan <nirbheek centricular com>
Date:   Fri May 29 00:31:35 2020 +0530

    meson: Only look for _NSGetEnviron when building for macOS
    
    On iOS it can cause build failures with some SDK versions, and its
    usage will also cause the app to be rejected on submission.

 meson.build | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 51554ef62..f51daf6b3 100644
--- a/meson.build
+++ b/meson.build
@@ -512,9 +512,14 @@ functions = [
   'wcslen',
   'wcsnlen',
   'sysctlbyname',
-  '_NSGetEnviron',
 ]
 
+# _NSGetEnviron is available on iOS too, but its usage gets apps rejected from
+# the app store since it's considered 'private API'
+if host_system == 'darwin'
+  functions += ['_NSGetEnviron']
+endif
+
 if glib_conf.has('HAVE_SYS_STATVFS_H')
   functions += ['statvfs']
 else