[cfe-commits] r153633 - /cfe/trunk/lib/Headers/unwind.h

[Rafael Espindola]

Author: rafael
Date: Wed Mar 28 22:37:17 2012
New Revision: 153633

URL: http://llvm.org/viewvc/llvm-project?rev=153633&view=rev
Log:
unwind.h fix for -fvisibility=hidden users. This fixes firefox build in a system
with libunwind installed.
Patch by Jeffrey Yasskin!

Modified:
    cfe/trunk/lib/Headers/unwind.h

Modified: cfe/trunk/lib/Headers/unwind.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Headers/unwind.h?rev=153633&r1=153632&r2=153633&view=diff
==============================================================================
--- cfe/trunk/lib/Headers/unwind.h (original)
+++ cfe/trunk/lib/Headers/unwind.h Wed Mar 28 22:37:17 2012
@@ -31,7 +31,19 @@
 #  define _SHOULD_UNDEFINE_GNU_SOURCE
 #  define _GNU_SOURCE
 # endif
-# include_next <unwind.h>
+// libunwind's unwind.h reflects the current visibility.  However, Mozilla
+// builds with -fvisibility=hidden and relies on gcc's unwind.h to reset the
+// visibility to default and export its contents.  gcc also allows users to
+// override its override by #defining HIDE_EXPORTS (but note, this only obeys
+// the user's -fvisibility setting; it doesn't hide any exports on its own).  We
+// imitate gcc's header here:
+# ifdef HIDE_EXPORTS
+#  include_next <unwind.h>
+# else
+#  pragma GCC visibility push(default)
+#  include_next <unwind.h>
+#  pragma GCC visibility pop
+# endif
 # ifdef _SHOULD_UNDEFINE_GNU_SOURCE
 #  undef _GNU_SOURCE
 #  undef _SHOULD_UNDEFINE_GNU_SOURCE