1 files changed, 28 insertions, 5 deletions

diff --git a/include/grail-bits.h b/include/grail-bits.h
index c151c11..dfe5367 100644
--- a/include/grail-bits.h
+++ b/include/grail-bits.h
@@ -27,6 +27,26 @@
 extern "C" {
 #endif
 
+/* Macros that set symbol visibilities in shared libraries properly.
+ * Adapted from http://gcc.gnu.org/wiki/Visibility
+ */
+
+#if defined _WIN32 || defined __CYGWIN__
+        #ifdef BUILDING_GRAIL
+                #define GRAIL_PUBLIC __declspec(dllexport)
+        #else
+                #define GRAIL_PUBLIC __declspec(dllimport)
+        #endif
+        #define GRAIL_PRIVATE
+#else
+        #if defined __GNUC__
+                #define GRAIL_PUBLIC __attribute__ ((visibility("default")))
+                #define GRAIL_PRIVATE  __attribute__ ((visibility("hidden")))
+        #else
+                #error "Unsupported compiler."
+        #endif
+#endif
+
 typedef unsigned char grail_mask_t;
 
 static inline void grail_mask_set(grail_mask_t *mask, int i)
@@ -52,12 +72,15 @@ static inline int grail_mask_get(const grail_mask_t *mask, int i)
         return (mask[i >> 3] >> (i & 7)) & 1;
 }
 
-void grail_mask_set_mask(grail_mask_t *a, const grail_mask_t *b, int bytes);
-void grail_mask_clear_mask(grail_mask_t *a, const grail_mask_t *b, int bytes);
+void GRAIL_PUBLIC grail_mask_set_mask(grail_mask_t *a, const grail_mask_t *b,
+                                      int bytes);
+void GRAIL_PUBLIC grail_mask_clear_mask(grail_mask_t *a, const grail_mask_t *b,
+                                        int bytes);
 
-int grail_mask_count(const grail_mask_t *mask, int bytes);
-int grail_mask_get_first(const grail_mask_t *mask, int bytes);
-int grail_mask_get_next(int i, const grail_mask_t *mask, int bytes);
+int GRAIL_PUBLIC grail_mask_count(const grail_mask_t *mask, int bytes);
+int GRAIL_PUBLIC grail_mask_get_first(const grail_mask_t *mask, int bytes);
+int GRAIL_PUBLIC grail_mask_get_next(int i, const grail_mask_t *mask,
+                                     int bytes);
 
 #define grail_mask_foreach(i, mask, bytes)                              \
         for (i = grail_mask_get_first(mask, bytes);                     \