Use intra-DSO calls when we build libbusybox. No-op for normal build.

This was Bernhard Fischer' idea.

   text    data     bss     dec     hex filename
 773549    7781    9740  791070   c121e busybox.t7/0_lib/libbusybox.so.1.11.0.svn_unstripped
 769683    7397    9740  786820   c0184 busybox.t9t/0_lib/libbusybox.so.1.11.0.svn_unstripped

1 files changed, 7 insertions, 0 deletions

diff --git a/util-linux/volume_id/volume_id_internal.h b/util-linux/volume_id/volume_id_internal.h
index 78b4a7b8a..6619d2c6e 100644
--- a/util-linux/volume_id/volume_id_internal.h
+++ b/util-linux/volume_id/volume_id_internal.h
@@ -21,6 +21,9 @@
 #include "libbb.h"
 #include "volume_id.h"
 
+#if __GNUC_PREREQ(4,1)
+# pragma GCC visibility push(hidden)
+#endif
 
 #define dbg(...) ((void)0)
 /* #define dbg(...) bb_error_msg(__VA_ARGS__) */
@@ -224,3 +227,7 @@ int volume_id_probe_udf(struct volume_id *id, uint64_t off);
 //int volume_id_probe_ufs(struct volume_id *id, uint64_t off);
 
 int volume_id_probe_xfs(struct volume_id *id, uint64_t off);
+
+#if __GNUC_PREREQ(4,1)
+# pragma GCC visibility pop
+#endif