[deliverable/binutils-gdb.git] / gdb / mem-break.c

/* Simulate breakpoints by patching locations in the target system, for GDB.

   Copyright (C) 1990, 1991, 1992, 1993, 1995, 1997, 1998, 1999, 2000, 2002,
   2007, 2008 Free Software Foundation, Inc.

   Contributed by Cygnus Support.  Written by John Gilmore.

   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/>.  */

#include "defs.h"

/* This file is only useful if BREAKPOINT_FROM_PC is set.  If not, we
   punt.  */

#include "symtab.h"
#include "breakpoint.h"
#include "inferior.h"
#include "target.h"


/* Insert a breakpoint on targets that don't have any better
   breakpoint support.  We read the contents of the target location
   and stash it, then overwrite it with a breakpoint instruction.
   BP_TGT->placed_address is the target location in the target
   machine.  BP_TGT->shadow_contents is some memory allocated for
   saving the target contents.  It is guaranteed by the caller to be
   long enough to save BREAKPOINT_LEN bytes (this is accomplished via
   BREAKPOINT_MAX).  */

int
default_memory_insert_breakpoint (struct bp_target_info *bp_tgt)
{
  int val;
  const unsigned char *bp;
  int bplen;

  /* Determine appropriate breakpoint contents and size for this address.  */
  bp = gdbarch_breakpoint_from_pc
       (current_gdbarch, &bp_tgt->placed_address, &bp_tgt->placed_size);
  if (bp == NULL)
    error (_("Software breakpoints not implemented for this target."));

  /* Save the memory contents.  */
  bp_tgt->shadow_len = bp_tgt->placed_size;
  val = target_read_memory (bp_tgt->placed_address, bp_tgt->shadow_contents,
			    bp_tgt->placed_size);

  /* Write the breakpoint.  */
  if (val == 0)
    val = target_write_memory (bp_tgt->placed_address, bp,
			       bp_tgt->placed_size);

  return val;
}


int
default_memory_remove_breakpoint (struct bp_target_info *bp_tgt)
{
  return target_write_memory (bp_tgt->placed_address, bp_tgt->shadow_contents,
			      bp_tgt->placed_size);
}


int
memory_insert_breakpoint (struct bp_target_info *bp_tgt)
{
  return gdbarch_memory_insert_breakpoint (current_gdbarch, bp_tgt);
}

int
memory_remove_breakpoint (struct bp_target_info *bp_tgt)
{
  return gdbarch_memory_remove_breakpoint (current_gdbarch, bp_tgt);
}
Commit	Line	Data
	1	/* Simulate breakpoints by patching locations in the target system, for GDB.
	2
	3	Copyright (C) 1990, 1991, 1992, 1993, 1995, 1997, 1998, 1999, 2000, 2002,
	4	2007, 2008 Free Software Foundation, Inc.
	5
	6	Contributed by Cygnus Support. Written by John Gilmore.
	7
	8	This file is part of GDB.
	9
	10	This program is free software; you can redistribute it and/or modify
	11	it under the terms of the GNU General Public License as published by
	12	the Free Software Foundation; either version 3 of the License, or
	13	(at your option) any later version.
	14
	15	This program is distributed in the hope that it will be useful,
	16	but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	GNU General Public License for more details.
	19
	20	You should have received a copy of the GNU General Public License
	21	along with this program. If not, see <http://www.gnu.org/licenses/>. */
	22
	23	#include "defs.h"
	24
	25	/* This file is only useful if BREAKPOINT_FROM_PC is set. If not, we
	26	punt. */
	27
	28	#include "symtab.h"
	29	#include "breakpoint.h"
	30	#include "inferior.h"
	31	#include "target.h"
	32
	33
	34	/* Insert a breakpoint on targets that don't have any better
	35	breakpoint support. We read the contents of the target location
	36	and stash it, then overwrite it with a breakpoint instruction.
	37	BP_TGT->placed_address is the target location in the target
	38	machine. BP_TGT->shadow_contents is some memory allocated for
	39	saving the target contents. It is guaranteed by the caller to be
	40	long enough to save BREAKPOINT_LEN bytes (this is accomplished via
	41	BREAKPOINT_MAX). */
	42
	43	int
	44	default_memory_insert_breakpoint (struct bp_target_info *bp_tgt)
	45	{
	46	int val;
	47	const unsigned char *bp;
	48	int bplen;
	49
	50	/* Determine appropriate breakpoint contents and size for this address. */
	51	bp = gdbarch_breakpoint_from_pc
	52	(current_gdbarch, &bp_tgt->placed_address, &bp_tgt->placed_size);
	53	if (bp == NULL)
	54	error (_("Software breakpoints not implemented for this target."));
	55
	56	/* Save the memory contents. */
	57	bp_tgt->shadow_len = bp_tgt->placed_size;
	58	val = target_read_memory (bp_tgt->placed_address, bp_tgt->shadow_contents,
	59	bp_tgt->placed_size);
	60
	61	/* Write the breakpoint. */
	62	if (val == 0)
	63	val = target_write_memory (bp_tgt->placed_address, bp,
	64	bp_tgt->placed_size);
	65
	66	return val;
	67	}
	68
	69
	70	int
	71	default_memory_remove_breakpoint (struct bp_target_info *bp_tgt)
	72	{
	73	return target_write_memory (bp_tgt->placed_address, bp_tgt->shadow_contents,
	74	bp_tgt->placed_size);
	75	}
	76
	77
	78	int
	79	memory_insert_breakpoint (struct bp_target_info *bp_tgt)
	80	{
	81	return gdbarch_memory_insert_breakpoint (current_gdbarch, bp_tgt);
	82	}
	83
	84	int
	85	memory_remove_breakpoint (struct bp_target_info *bp_tgt)
	86	{
	87	return gdbarch_memory_remove_breakpoint (current_gdbarch, bp_tgt);
	88	}