From 1d567592b18ea9796515436754877aac3948bd29 Mon Sep 17 00:00:00 2001
From: Paul Sokolovsky <pfalcon@users.sourceforge.net>
Date: Wed, 28 May 2014 15:37:22 +0300
Subject: [PATCH] unix/gccollect.c: Make Clang workaround apply only to it.
 Unbreaks gcc builds.

---
 unix/gccollect.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/unix/gccollect.c b/unix/gccollect.c
index 1b5a38ffc6..d934f9cae2 100644
--- a/unix/gccollect.c
+++ b/unix/gccollect.c
@@ -43,17 +43,25 @@ typedef machine_uint_t regs_t[6];
 
 void gc_helper_get_regs(regs_t arr) {
     register long rbx asm ("rbx");
-    asm("" : "=r"(rbx));
     register long rbp asm ("rbp");
-    asm("" : "=r"(rbp));
     register long r12 asm ("r12");
-    asm("" : "=r"(r12));
     register long r13 asm ("r13");
-    asm("" : "=r"(r13));
     register long r14 asm ("r14");
-    asm("" : "=r"(r14));
     register long r15 asm ("r15");
+#ifdef __clang__
+    // TODO:
+    // This is dirty workaround for Clang. It tries to get around
+    // uncompliant (wrt to GCC) behavior of handling register variables.
+    // Application of this patch here is random, and done only to unbreak
+    // MacOS build. Better, cross-arch ways to deal with Clang issues should
+    // be found.
+    asm("" : "=r"(rbx));
+    asm("" : "=r"(rbp));
+    asm("" : "=r"(r12));
+    asm("" : "=r"(r13));
+    asm("" : "=r"(r14));
     asm("" : "=r"(r15));
+#endif
     arr[0] = rbx;
     arr[1] = rbp;
     arr[2] = r12;