From bafc9c70e1052a3413afc879d319ee3f89499113 Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Tue, 22 Mar 2016 20:42:07 +0100
Subject: [PATCH] Only use .private_extern if this is supported

---
 configure.ac                                  | 21 +++++++++++++++++++
 .../curve25519/sandy2x/fe51_mul.S             |  2 ++
 .../curve25519/sandy2x/fe51_nsquare.S         |  2 ++
 .../curve25519/sandy2x/fe51_pack.S            |  2 ++
 .../curve25519/sandy2x/ladder.S               |  2 ++
 .../curve25519/sandy2x/ladder_base.S          |  2 ++
 6 files changed, 31 insertions(+)

diff --git a/configure.ac b/configure.ac
index 2328ca4a..79a03ac0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -529,6 +529,27 @@ __asm__ __volatile__ ("xchgl %%ebx, %k1; cpuid; xchgl %%ebx, %k1" :
   ])
 AC_SUBST(HAVE_CPUID_V)
 
+HAVE_VISIBILITY_V=0
+AS_IF([test "$enable_asm" != "no"],[
+  AC_MSG_CHECKING(if the private_extern asm directive is supported)
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ ]], [[
+__asm__ __volatile__ (".private_extern dummy_symbol \n"
+                      ".private_extern _dummy_symbol \n"
+                      ".globl dummy_symbol \n"
+                      ".globl _dummy_symbol \n"
+                      "dummy_symbol: \n"
+                      "_dummy_symbol: \n"
+                      "    nop \n"
+);
+  ]])],
+  [AC_MSG_RESULT(yes)
+   AC_DEFINE([HAVE_VISIBILITY], [1], [the private_extern asm directive
+is supported])
+   HAVE_VISIBILITY_V=1],
+  [AC_MSG_RESULT(no)])
+  ])
+AC_SUBST(HAVE_VISIBILITY_V)
+
 AC_MSG_CHECKING(if weak symbols are supported)
 AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 __attribute__((weak)) void __dummy(void *x) { }
diff --git a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_mul.S b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_mul.S
index 4249db51..7f793ff9 100644
--- a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_mul.S
+++ b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_mul.S
@@ -7,8 +7,10 @@
 #include "consts_namespace.h"
 .text
 .p2align 5
+#ifdef HAVE_VISIBILITY
 .private_extern fe51_mul
 .private_extern _fe51_mul
+#endif
 .globl fe51_mul
 .globl _fe51_mul
 #ifdef __ELF__
diff --git a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_nsquare.S b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_nsquare.S
index 64ab2b5a..a8a14aef 100644
--- a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_nsquare.S
+++ b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_nsquare.S
@@ -8,8 +8,10 @@
 #include "consts_namespace.h"
 .p2align 5
 
+#ifdef HAVE_VISIBILITY
 .private_extern fe51_nsquare
 .private_extern _fe51_nsquare
+#endif
 .globl fe51_nsquare
 .globl _fe51_nsquare
 #ifdef __ELF__
diff --git a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_pack.S b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_pack.S
index b6128ee3..65f2c08d 100644
--- a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_pack.S
+++ b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_pack.S
@@ -8,8 +8,10 @@
 #include "consts_namespace.h"
 .p2align 5
 
+#ifdef HAVE_VISIBILITY
 .private_extern fe51_pack
 .private_extern _fe51_pack
+#endif
 .globl fe51_pack
 .globl _fe51_pack
 #ifdef __ELF__
diff --git a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/ladder.S b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/ladder.S
index abb8fd68..412aed1d 100644
--- a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/ladder.S
+++ b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/ladder.S
@@ -4,8 +4,10 @@
 #include "consts_namespace.h"
 .p2align 5
 
+#ifdef HAVE_VISIBILITY
 .private_extern ladder
 .private_extern _ladder
+#endif
 .globl ladder
 .globl _ladder
 #ifdef __ELF__
diff --git a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/ladder_base.S b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/ladder_base.S
index 7d21687e..1efd9dc3 100644
--- a/src/libsodium/crypto_scalarmult/curve25519/sandy2x/ladder_base.S
+++ b/src/libsodium/crypto_scalarmult/curve25519/sandy2x/ladder_base.S
@@ -4,8 +4,10 @@
 #include "consts_namespace.h"
 .p2align 5
 
+#ifdef HAVE_VISIBILITY
 .private_extern ladder_base
 .private_extern _ladder_base
+#endif
 .globl ladder_base
 .globl _ladder_base
 #ifdef __ELF__