[PATCH] Enable hidden visibility in libc.a compiled with PIE

[H.J. Lu]

When building libc.a with PIE, enable hidden visibility to allow direct
access to definitions within libc.a without using GOT.

Size comparison of elf/ldconfig when the compiler defaults to -fPIE:

On x86-64:
        text	   data	    bss	    dec	    hex
Before: 619206	  20132	   5488	 644826	  9d6da
After : 619062	  20132	   5488	 644682	  9d64a
On i686:
        text	   data	    bss	    dec	    hex
Before: 556305	  10816	   3056	 570177	  8b341
After : 553688	  10756	   3056	 567500	  8a8cc

OK for master?

H.J.
---
	* include/libc-symbols.h (attribute_hidden): Enable hidden
	visibility in libc.a compiled with PIE.
---
 include/libc-symbols.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index fe3ab81c51..d6a1c260f6 100644
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -363,7 +363,8 @@ for linking")
   strong_alias(real, name)
 #endif
 
-#if defined SHARED || defined LIBC_NONSHARED
+#if defined SHARED || defined LIBC_NONSHARED \
+  || (BUILD_PIE_DEFAULT && IS_IN (libc))
 # define attribute_hidden __attribute__ ((visibility ("hidden")))
 #else
 # define attribute_hidden
-- 
2.13.4