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, 9 insertions, 0 deletions

diff --git a/include/dump.h b/include/dump.h
index 7e1715430..20c39c41e 100644
--- a/include/dump.h
+++ b/include/dump.h
@@ -1,4 +1,9 @@
 /* vi: set sw=4 ts=4: */
+
+#if __GNUC_PREREQ(4,1)
+# pragma GCC visibility push(hidden)
+#endif
+
 #define F_IGNORE        0x01            /* %_A */
 #define F_SETREP        0x02            /* rep count set, not default */
 #define F_ADDRESS       0x001           /* print offset */
@@ -48,3 +53,7 @@ extern int bb_dump_blocksize;				/* data block size */
 extern int bb_dump_length;                      /* max bytes to read */
 extern enum _vflag bb_dump_vflag;
 extern off_t bb_dump_skip;                      /* bytes to skip */
+
+#if __GNUC_PREREQ(4,1)
+# pragma GCC visibility pop
+#endif