gdb/x86-nat.h

/* Native-dependent code for x86 (i386 and x86-64).

   Low level functions to implement Oeprating System specific
   code to manipulate x86 debug registers.

   Copyright (C) 2009-2018 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.

   This program 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.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef X86_NAT_H
#define X86_NAT_H 1

#include "breakpoint.h"
#include "nat/x86-dregs.h"
#include "target.h"

/* Hardware-assisted breakpoints and watchpoints.  */

/* Use this function to set x86_dr_low debug_register_length field
   rather than setting it directly to check that the length is only
   set once.  It also enables the 'maint set/show show-debug-regs' 
   command.  */

extern void x86_set_debug_register_length (int len);

/* Use this function to reset the x86-nat.c debug register state.  */

extern void x86_cleanup_dregs (void);

/* Called whenever GDB is no longer debugging process PID.  It deletes
   data structures that keep track of debug register state.  */

extern void x86_forget_process (pid_t pid);

/* Helper functions used by x86_nat_target below.  See their
   definitions.  */

extern int x86_can_use_hw_breakpoint (enum bptype type, int cnt, int othertype);
extern int x86_region_ok_for_hw_watchpoint (CORE_ADDR addr, int len);
extern int x86_stopped_by_watchpoint ();
extern int x86_stopped_data_address (CORE_ADDR *addr_p);
extern int x86_insert_watchpoint (CORE_ADDR addr, int len,
			   enum target_hw_bp_type type,
			   struct expression *cond);
extern int x86_remove_watchpoint (CORE_ADDR addr, int len,
			   enum target_hw_bp_type type,
			   struct expression *cond);
extern int x86_insert_hw_breakpoint (struct gdbarch *gdbarch,
			      struct bp_target_info *bp_tgt);
extern int x86_remove_hw_breakpoint (struct gdbarch *gdbarch,
				     struct bp_target_info *bp_tgt);
extern int x86_stopped_by_hw_breakpoint ();

/* Convenience template mixin used to add x86 watchpoints support to a
   target.  */

template <typename BaseTarget>
struct x86_nat_target : public BaseTarget
{
  /* Hook in the x86 hardware watchpoints/breakpoints support.  */

  /* After a watchpoint trap, the PC points to the instruction after
     the one that caused the trap.  Therefore we don't need to step
     over it.  But we do need to reset the status register to avoid
     another trap.  */
  bool have_continuable_watchpoint () override
  { return true; }

  int can_use_hw_breakpoint (enum bptype type, int cnt, int othertype) override
  { return x86_can_use_hw_breakpoint (type, cnt, othertype); }

  int region_ok_for_hw_watchpoint (CORE_ADDR addr, int len) override
  { return x86_region_ok_for_hw_watchpoint (addr, len); }

  int insert_watchpoint (CORE_ADDR addr, int len,
			 enum target_hw_bp_type type,
			 struct expression *cond) override
  { return x86_insert_watchpoint (addr, len, type, cond); }

  int remove_watchpoint (CORE_ADDR addr, int len,
			 enum target_hw_bp_type type,
			 struct expression *cond) override
  { return x86_remove_watchpoint (addr, len, type, cond); }

  int insert_hw_breakpoint (struct gdbarch *gdbarch,
			    struct bp_target_info *bp_tgt) override
  { return x86_insert_hw_breakpoint (gdbarch, bp_tgt); }

  int remove_hw_breakpoint (struct gdbarch *gdbarch,
			    struct bp_target_info *bp_tgt) override
  { return x86_remove_hw_breakpoint (gdbarch, bp_tgt); }

  bool stopped_by_watchpoint () override
  { return x86_stopped_by_watchpoint (); }

  bool stopped_data_address (CORE_ADDR *addr_p) override
  { return x86_stopped_data_address (addr_p); }

  /* A target must provide an implementation of the
     "supports_stopped_by_hw_breakpoint" target method before this
     callback will be used.  */
  bool stopped_by_hw_breakpoint () override
  { return x86_stopped_by_hw_breakpoint (); }
};

#endif /* X86_NAT_H */