cpp-d1064d

[cross.git] / i686-linux-gnu-4.7 / usr / include / x86_64-linux-gnu / bits / indirect-return.h

diff --git a/i686-linux-gnu-4.7/usr/include/x86_64-linux-gnu/bits/indirect-return.h b/i686-linux-gnu-4.7/usr/include/x86_64-linux-gnu/bits/indirect-return.h
new file mode 100644 (file)
index 0000000..d1acaca
--- /dev/null
+++ b/i686-linux-gnu-4.7/usr/include/x86_64-linux-gnu/bits/indirect-return.h
@@ -0,0 +1,37 @@
+/* Definition of __INDIRECT_RETURN.  x86 version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _UCONTEXT_H
+# error "Never include <bits/indirect-return.h> directly; use <ucontext.h> instead."
+#endif
+
+/* On x86, swapcontext returns via indirect branch when the shadow stack
+   is enabled.  Define __INDIRECT_RETURN to indicate whether swapcontext
+   returns via indirect branch.  */
+#if defined __CET__ && (__CET__ & 2) != 0
+# if __glibc_has_attribute (__indirect_return__)
+#  define __INDIRECT_RETURN __attribute__ ((__indirect_return__))
+# else
+/* Newer compilers provide the indirect_return attribute, but without
+   it we can use returns_twice to affect the optimizer in the same
+   way and avoid unsafe optimizations.  */
+#  define __INDIRECT_RETURN __attribute__ ((__returns_twice__))
+# endif
+#else
+# define __INDIRECT_RETURN
+#endif