gdb/i386-cygwin-tdep.c

/* Target-dependent code for Cygwin running on i386's, for GDB.

   Copyright (C) 2003, 2007, 2008, 2009, 2010 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 "defs.h"
#include "osabi.h"
#include "gdb_string.h"
#include "i386-tdep.h"
#include "windows-tdep.h"
#include "regset.h"
#include "gdb_obstack.h"
#include "xml-support.h"
#include "gdbcore.h"
#include "solib.h"
#include "solib-target.h"

/* Core file support.  */

/* This vector maps GDB's idea of a register's number into an address
   in the windows exception context vector.  */

static int i386_windows_gregset_reg_offset[] =
{
  176, /* eax */
  172, /* ecx */
  168, /* edx */
  164, /* ebx */

  196, /* esp */
  180, /* ebp */
  160, /* esi */
  156, /* edi */

  184, /* eip */
  192, /* eflags */
  188, /* cs */
  200, /* ss */

  152, /* ds */
  148, /* es */
  144, /* fs */
  140, /* gs */

  56, /* FloatSave.RegisterArea[0 * 10] */
  66, /* FloatSave.RegisterArea[1 * 10] */
  76, /* FloatSave.RegisterArea[2 * 10] */
  86, /* FloatSave.RegisterArea[3 * 10] */
  96, /* FloatSave.RegisterArea[4 * 10] */
  106, /* FloatSave.RegisterArea[5 * 10] */
  116, /* FloatSave.RegisterArea[6 * 10] */
  126, /* FloatSave.RegisterArea[7 * 10] */

  28, /* FloatSave.ControlWord */
  32, /* FloatSave.StatusWord */
  36, /* FloatSave.TagWord */
  44, /* FloatSave.ErrorSelector */
  40, /* FloatSave.ErrorOffset */
  52, /* FloatSave.DataSelector */
  48, /* FloatSave.DataOffset */
  44, /* FloatSave.ErrorSelector */

  /* XMM0-7 */
  364, /* ExtendedRegisters[10*16] */
  380, /* ExtendedRegisters[11*16] */
  396, /* ExtendedRegisters[12*16] */
  412, /* ExtendedRegisters[13*16] */
  428, /* ExtendedRegisters[14*16] */
  444, /* ExtendedRegisters[15*16] */
  460, /* ExtendedRegisters[16*16] */
  476, /* ExtendedRegisters[17*16] */

  /* MXCSR */
  228 /* ExtendedRegisters[24] */
};

#define I386_WINDOWS_SIZEOF_GREGSET 716

/* Return the appropriate register set for the core section identified
   by SECT_NAME and SECT_SIZE.  */

static const struct regset *
i386_windows_regset_from_core_section (struct gdbarch *gdbarch,
				     const char *sect_name, size_t sect_size)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  if (strcmp (sect_name, ".reg") == 0
      && sect_size == I386_WINDOWS_SIZEOF_GREGSET)
    {
      if (tdep->gregset == NULL)
        tdep->gregset = regset_alloc (gdbarch, i386_supply_gregset,
                                      i386_collect_gregset);
      return tdep->gregset;
    }

  return NULL;
}

struct cpms_data
{
  struct gdbarch *gdbarch;
  struct obstack *obstack;
  int module_count;
};

static void
core_process_module_section (bfd *abfd, asection *sect, void *obj)
{
  struct cpms_data *data = obj;
  enum bfd_endian byte_order = gdbarch_byte_order (data->gdbarch);

  char *module_name;
  size_t module_name_size;
  CORE_ADDR base_addr;

  char *buf = NULL;

  if (strncmp (sect->name, ".module", 7) != 0)
    return;

  buf = xmalloc (bfd_get_section_size (sect) + 1);
  if (!buf)
    {
      printf_unfiltered ("memory allocation failed for %s\n", sect->name);
      goto out;
    }
  if (!bfd_get_section_contents (abfd, sect,
				 buf, 0, bfd_get_section_size (sect)))
    goto out;



  /* A DWORD (data_type) followed by struct windows_core_module_info.  */

  base_addr =
    extract_unsigned_integer (buf + 4, 4, byte_order);

  module_name_size =
    extract_unsigned_integer (buf + 8, 4, byte_order);

  module_name = buf + 12;
  if (module_name - buf + module_name_size > bfd_get_section_size (sect))
    goto out;

  /* The first module is the .exe itself.  */
  if (data->module_count != 0)
    windows_xfer_shared_library (module_name, base_addr,
				 data->gdbarch, data->obstack);
  data->module_count++;

out:
  if (buf)
    xfree (buf);
  return;
}

static LONGEST
windows_core_xfer_shared_libraries (struct gdbarch *gdbarch,
				  gdb_byte *readbuf,
				  ULONGEST offset, LONGEST len)
{
  struct obstack obstack;
  const char *buf;
  LONGEST len_avail;
  struct cpms_data data = { gdbarch, &obstack, 0 };

  obstack_init (&obstack);
  obstack_grow_str (&obstack, "<library-list>\n");
  bfd_map_over_sections (core_bfd,
			 core_process_module_section,
			 &data);
  obstack_grow_str0 (&obstack, "</library-list>\n");

  buf = obstack_finish (&obstack);
  len_avail = strlen (buf);
  if (offset >= len_avail)
    return 0;

  if (len > len_avail - offset)
    len = len_avail - offset;
  memcpy (readbuf, buf + offset, len);

  obstack_free (&obstack, NULL);
  return len;
}

static CORE_ADDR
i386_cygwin_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
{
  return i386_pe_skip_trampoline_code (frame, pc, NULL);
}

static void
i386_cygwin_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  set_gdbarch_skip_trampoline_code (gdbarch, i386_cygwin_skip_trampoline_code);

  set_gdbarch_skip_main_prologue (gdbarch, i386_skip_main_prologue);

  tdep->struct_return = reg_struct_return;

  tdep->gregset_reg_offset = i386_windows_gregset_reg_offset;
  tdep->gregset_num_regs = ARRAY_SIZE (i386_windows_gregset_reg_offset);
  tdep->sizeof_gregset = I386_WINDOWS_SIZEOF_GREGSET;

  set_solib_ops (gdbarch, &solib_target_so_ops);

  /* Core file support.  */
  set_gdbarch_regset_from_core_section
    (gdbarch, i386_windows_regset_from_core_section);
  set_gdbarch_core_xfer_shared_libraries
    (gdbarch, windows_core_xfer_shared_libraries);
}

static enum gdb_osabi
i386_cygwin_osabi_sniffer (bfd *abfd)
{
  char *target_name = bfd_get_target (abfd);

  /* Interix also uses pei-i386.
     We need a way to distinguish between the two. */
  if (strcmp (target_name, "pei-i386") == 0)
    return GDB_OSABI_CYGWIN;

  /* Cygwin uses elf core dumps.  Do not claim all ELF executables,
     check whether there is a .reg section of proper size.  */
  if (strcmp (target_name, "elf32-i386") == 0)
    {
      asection *section = bfd_get_section_by_name (abfd, ".reg");
      if (section
	  && bfd_section_size (abfd, section) == I386_WINDOWS_SIZEOF_GREGSET)
	return GDB_OSABI_CYGWIN;
    }

  return GDB_OSABI_UNKNOWN;
}

/* Provide a prototype to silence -Wmissing-prototypes.  */
void _initialize_i386_cygwin_tdep (void);

void
_initialize_i386_cygwin_tdep (void)
{
  gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour,
                                  i386_cygwin_osabi_sniffer);

  /* Cygwin uses elf core dumps.  */
  gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_elf_flavour,
                                  i386_cygwin_osabi_sniffer);

  gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_CYGWIN,
                          i386_cygwin_init_abi);
}