[Bug debug/54568] New: Unused codes in unwind-dw2-fde.c on PT_GNU_EH_FRAME targets

["hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54568

             Bug #: 54568
           Summary: Unused codes in unwind-dw2-fde.c on PT_GNU_EH_FRAME
                    targets
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: hjl.tools@gmail.com


From

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24724#c15

--
On a system whose linker supports --eh-frame-hdr, we will use the version of
_Unwind_Find_FDE in unwind-dw2-fde-dip.c.  It will override the version in
unwind-dw2-fde.c by renaming it via #define.  This file is selected by
libgcc/config/t-eh-dw2-dip.  It will still call the version of
_Unwind_Find_FDE, but that function will only look through files registered by
__register_frame_info_bases.  __register_frame_info_bases is called by
crtstuff.c, but it is only called on systems whose linker does not support
--eh-frame-hdr.
--

On PT_GNU_EH_FRAME targets, even __register_frame_info_bases isn't
defined/used, we still include unwind-dw2-fde.c and call its
_Unwind_Find_FDE as _Unwind_Find_registered_FDE.  Should we skip
the whole thing?