clang doesn't propagate attributes like "asm labels" and "visibility(hidden)"

to builtins like mem{set,cpy,move} and __stack_smash_handler.  So, when
building with clang, instead mark those as protected visibility to get rid
of the PLT relocations.  We can't take the address of them then, but that's
ok: it's a build-time error not a run-time error.

ok kettenis@

2 files changed, 8 insertions, 4 deletions

diff --git a/lib/libc/arch/amd64/string/memmove.S b/lib/libc/arch/amd64/string/memmove.S
index f0e01654c2f..da244c332a1 100644
--- a/lib/libc/arch/amd64/string/memmove.S
+++ b/lib/libc/arch/amd64/string/memmove.S
@@ -51,12 +51,14 @@ ENTRY(memmove)
 	subq	%rsi,%rax
 	cmpq	%rcx,%rax	/* overlapping? */
 	jb	1f
+#ifdef memcpy_in_asm
 	jmp	2f		/* nope */
 
-// ENTRY(memcpy)
+ENTRY(memcpy)
 	movq	%rdi,%r11	/* save dest */
 	movq	%rdx,%rcx
 2:
+#endif
 	cld			/* copy forwards. */
 	shrq	$3,%rcx		/* copy by words */
 	rep
@@ -85,6 +87,8 @@ ENTRY(memmove)
 	movq	%r11,%rax
 	cld
 	ret
-// END(memcpy)
-END_STRONG(memmove)
+#ifdef memcpy_in_asm
+END_BUILTIN(memcpy)
+#endif
+END_BUILTIN(memmove)
 END_WEAK(bcopy)
diff --git a/lib/libc/arch/amd64/string/memset.S b/lib/libc/arch/amd64/string/memset.S
index b3f4ffa17bf..2a8645cb1c3 100644
--- a/lib/libc/arch/amd64/string/memset.S
+++ b/lib/libc/arch/amd64/string/memset.S
@@ -53,4 +53,4 @@ L1:	rep
 	movq	%r11,%rax
 
 	ret
-END_STRONG(memset)
+END_BUILTIN(memset)