From 26a7f37a5423cc8252d88ee8482f96b5692c0dce Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Tue, 1 Oct 2019 11:40:41 +0100
Subject: [PATCH] Set ELF visibility to keep all of our external symbols to
 ourselves.

---
 catacomb-python.h | 15 +++++++++++++++
 catacomb.c        |  2 +-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/catacomb-python.h b/catacomb-python.h
index df29099..5815343 100644
--- a/catacomb-python.h
+++ b/catacomb-python.h
@@ -120,6 +120,21 @@
 #include <catacomb/share.h>
 #include <catacomb/gfshare.h>
 
+/*----- Other preliminaries -----------------------------------------------*/
+
+#define GOBBLE_SEMI extern int notexist
+#if defined(__GNUC__) && defined(__ELF__)
+#  define PRIVATE_SYMBOLS _Pragma("GCC visibility push(hidden)") GOBBLE_SEMI
+#  define PUBLIC_SYMBOLS _Pragma("GCC visibility pop") GOBBLE_SEMI
+#  define EXPORT __attribute__((__visibility__("default")))
+#else
+#  define PRIVATE_SYMBOLS GOBBLE_SEMI
+#  define PUBLIC_SYMBOLS GOBBLE_SEMI
+#  define EXPORT
+#endif
+
+PRIVATE_SYMBOLS;
+
 /*----- Utility macros ----------------------------------------------------*/
 
 #define RETURN_OBJ(obj) do { Py_INCREF(obj); return (obj); } while (0)
diff --git a/catacomb.c b/catacomb.c
index b596b5e..affb5d3 100644
--- a/catacomb.c
+++ b/catacomb.c
@@ -167,7 +167,7 @@ static void init_random(void)
 #endif
 }
 
-void init_base(void)
+EXPORT void init_base(void)
 {
   PyObject *mod;
   addmethods(methods);
-- 
2.11.0