Implement dummy_id for NaCl architecture because we need to sandbox frame pointer.

gdb/nacl-tdep.c

 /* Target-dependent code for NaCl.
 
    Copyright (C) 2001, 2003-2012 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
    This program 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 of the License, or
    (at your option) any later version.
@@ skipping 144 matching lines @@
     {
       insert_single_step_breakpoint (gdbarch,
                                      get_frame_address_space (frame),
                                      bp_pc);
       return 1;
     }
 
   return 0;
 }
 
+static struct frame_id
+amd64_nacl_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
+{
+  CORE_ADDR fp;
+
+  fp = get_frame_register_unsigned (this_frame, AMD64_RBP_REGNUM) + 16;
+  fp = amd64_nacl_addr_bits_remove(gdbarch, fp);
+
+  return frame_id_build (fp, get_frame_pc (this_frame));
+}
+
 static void
 amd64_nacl_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 
   linux_init_abi (info, gdbarch);
   amd64_init_abi (info, gdbarch);
   tdep->tdesc = tdesc_amd64_linux;
   set_solib_svr4_fetch_link_map_offsets (gdbarch,
                                          amd64_nacl_fetch_link_map_offsets);
@@ skipping 17 matching lines @@
 
   /* How to extract addresses from registers.  */
   set_gdbarch_addr_bits_remove (gdbarch, amd64_nacl_addr_bits_remove);
   set_gdbarch_unwind_pc (gdbarch, amd64_nacl_unwind_pc);
   set_gdbarch_unwind_sp (gdbarch, amd64_nacl_unwind_sp);
 
   /* Where to set breakpoints.  */
   set_gdbarch_adjust_breakpoint_address (gdbarch,
                                          amd64_nacl_adjust_breakpoint_address);
   set_gdbarch_software_single_step (gdbarch, amd64_nacl_software_single_step);
+  /* Recognizing dummy frames.  */
+  set_gdbarch_dummy_id(gdbarch, amd64_nacl_dummy_id);
 }
 
 /* Provide a prototype to silence -Wmissing-prototypes.  */
 extern void _initialize_nacl_tdep (void);
 
 void
 _initialize_nacl_tdep (void)
 {
   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_elf_flavour,
                                   nacl_osabi_sniffer);
 
   gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
                           GDB_OSABI_NACL, amd64_nacl_init_abi);
 
   gdbarch_register_osabi (bfd_arch_i386, 0,
                           GDB_OSABI_NACL, i386_nacl_init_abi);
 }