[AArch64, libgcc] Add missing file, forget "svn add"

From-SVN: r244674

libgcc/config/aarch64/aarch64-unwind.h

+/* Copyright (C) 2017 Free Software Foundation, Inc.
+   Contributed by ARM Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC 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 General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef AARCH64_UNWIND_H
+#define AARCH64_UNWIND_H
+
+#define DWARF_REGNUM_AARCH64_RA_STATE 34
+
+#define MD_POST_EXTRACT_ROOT_ADDR(addr)  __builtin_aarch64_xpaclri (addr)
+#define MD_POST_EXTRACT_FRAME_ADDR(context, fs, addr) \
+  aarch64_post_extract_frame_addr (context, fs, addr)
+#define MD_POST_FROB_EH_HANDLER_ADDR(current, target, addr) \
+  aarch64_post_frob_eh_handler_addr (current, target, addr)
+#define MD_FROB_UPDATE_CONTEXT(context, fs) \
+  aarch64_frob_update_context (context, fs)
+
+/* Do AArch64 private extraction on ADDR based on context info CONTEXT and
+   unwind frame info FS.  If ADDR is signed, we do address authentication on it
+   using CFA of current frame.  */
+
+static inline void *
+aarch64_post_extract_frame_addr (struct _Unwind_Context *context,
+				 _Unwind_FrameState *fs, void *addr)
+{
+  if (fs->regs.reg[DWARF_REGNUM_AARCH64_RA_STATE].loc.offset & 0x1)
+    {
+      _Unwind_Word salt = (_Unwind_Word) context->cfa;
+      return __builtin_aarch64_autia1716 (addr, salt);
+    }
+  else
+    return addr;
+}
+
+/* Do AArch64 private frob on exception handler's address HANDLER_ADDR before
+   installing it into current context CURRENT.  TARGET is currently not used.
+   We need to sign exception handler's address if CURRENT itself is signed.  */
+
+static inline void *
+aarch64_post_frob_eh_handler_addr (struct _Unwind_Context *current,
+				   struct _Unwind_Context *target
+				   ATTRIBUTE_UNUSED,
+				   void *handler_addr)
+{
+  if (current->flags & RA_A_SIGNED_BIT)
+    return __builtin_aarch64_pacia1716 (handler_addr,
+					(_Unwind_Word) current->cfa);
+  else
+    return handler_addr;
+}
+
+/* Do AArch64 private initialization on CONTEXT based on frame info FS.  Mark
+   CONTEXT as return address signed if bit 0 of DWARF_REGNUM_AARCH64_RA_STATE is
+   set.  */
+
+static inline void
+aarch64_frob_update_context (struct _Unwind_Context *context,
+			     _Unwind_FrameState *fs)
+{
+  if (fs->regs.reg[DWARF_REGNUM_AARCH64_RA_STATE].loc.offset & 0x1)
+    /* The flag is used for re-authenticating EH handler's address.  */
+    context->flags |= RA_A_SIGNED_BIT;
+
+  return;
+}
+
+#endif /* defined AARCH64_UNWIND_H */