gdb: add target_ops::supports_displaced_step

[deliverable/binutils-gdb.git] / gdbserver / win32-arm-low.cc

/* Copyright (C) 2007-2020 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/>.  */

#include "server.h"
#include "win32-low.h"

using namespace windows_nat;

#ifndef CONTEXT_FLOATING_POINT
#define CONTEXT_FLOATING_POINT 0
#endif

/* Defined in auto-generated file reg-arm.c.  */
void init_registers_arm (void);
extern const struct target_desc *tdesc_arm;

static void
arm_get_thread_context (windows_thread_info *th)
{
  th->context.ContextFlags = \
    CONTEXT_FULL | \
    CONTEXT_FLOATING_POINT;

  GetThreadContext (th->h, &th->context);
}

#define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
static const int mappings[] = {
  context_offset (R0),
  context_offset (R1),
  context_offset (R2),
  context_offset (R3),
  context_offset (R4),
  context_offset (R5),
  context_offset (R6),
  context_offset (R7),
  context_offset (R8),
  context_offset (R9),
  context_offset (R10),
  context_offset (R11),
  context_offset (R12),
  context_offset (Sp),
  context_offset (Lr),
  context_offset (Pc),
  -1, /* f0 */
  -1, /* f1 */
  -1, /* f2 */
  -1, /* f3 */
  -1, /* f4 */
  -1, /* f5 */
  -1, /* f6 */
  -1, /* f7 */
  -1, /* fps */
  context_offset (Psr),
};
#undef context_offset

/* Return a pointer into a CONTEXT field indexed by gdb register number.
   Return a pointer to an dummy register holding zero if there is no
   corresponding CONTEXT field for the given register number.  */
static char *
regptr (CONTEXT* c, int r)
{
  if (mappings[r] < 0)
  {
    static ULONG zero;
    /* Always force value to zero, in case the user tried to write
       to this register before.  */
    zero = 0;
    return (char *) &zero;
  }
  else
    return (char *) c + mappings[r];
}

/* Fetch register from gdbserver regcache data.  */
static void
arm_fetch_inferior_register (struct regcache *regcache,
			     windows_thread_info *th, int r)
{
  char *context_offset = regptr (&th->context, r);
  supply_register (regcache, r, context_offset);
}

/* Store a new register value into the thread context of TH.  */
static void
arm_store_inferior_register (struct regcache *regcache,
			     windows_thread_info *th, int r)
{
  collect_register (regcache, r, regptr (&th->context, r));
}

static void
arm_arch_setup (void)
{
  init_registers_arm ();
  win32_tdesc = tdesc_arm;
}

/* Implement win32_target_ops "num_regs" method.  */

static int
arm_num_regs (void)
{
  return sizeof (mappings) / sizeof (mappings[0]),
}

/* Correct in either endianness.  We do not support Thumb yet.  */
static const unsigned long arm_wince_breakpoint = 0xe6000010;
#define arm_wince_breakpoint_len 4

/* Implement win32_target_ops "get_pc" method.  */

static CORE_ADDR
arm_win32_get_pc (struct regcache *regcache)
{
  uint32_t pc;

  collect_register_by_name (regcache, "pc", &pc);
  return (CORE_ADDR) pc;
}

/* Implement win32_target_ops "set_pc" method.  */

static void
arm_win32_set_pc (struct regcache *regcache, CORE_ADDR pc)
{
  uint32_t newpc = pc;

  supply_register_by_name (regcache, "pc", &newpc);
}

struct win32_target_ops the_low_target = {
  arm_arch_setup,
  arm_num_regs,
  NULL, /* initial_stuff */
  arm_get_thread_context,
  NULL, /* prepare_to_resume */
  NULL, /* thread_added */
  arm_fetch_inferior_register,
  arm_store_inferior_register,
  NULL, /* single_step */
  (const unsigned char *) &arm_wince_breakpoint,
  arm_wince_breakpoint_len,
  0,
  arm_win32_get_pc,
  arm_win32_set_pc,
  /* Watchpoint related functions.  See target.h for comments.  */
  NULL, /* supports_z_point_type */
  NULL, /* insert_point */
  NULL, /* remove_point */
  NULL, /* stopped_by_watchpoint */
  NULL  /* stopped_data_address */
};