gdb/i386-cygwin-tdep.c

   1 /* Target-dependent code for Cygwin running on i386's, for GDB.
   2    Copyright 2003 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 #include "defs.h"
  21
  22 #include "gdb_string.h"
  23 #include "gdbcore.h"
  24 #include "i386-tdep.h"
  25 #include "osabi.h"
  26 #include "frame.h"
  27 #include "dummy-frame.h"
  28
  29 static int
  30 i386_cygwin_frame_chain_valid (CORE_ADDR chain, struct frame_info *thisframe)
  31 {
  32   /* In the context where this is used, we get the saved PC before we've
  33      successfully unwound far enough to be sure what we've got (it may
  34      be a signal handler caller).  If we're dealing with a signal
  35      handler caller, this will return valid, which is fine.  If not,
  36      it'll make the correct test.  */
  37   return ((get_frame_type (thisframe) == SIGTRAMP_FRAME) || chain != 0);
  38 }
  39 /* Return the chain-pointer for FRAME.  In the case of the i386, the
  40    frame's nominal address is the address of a 4-byte word containing
  41    the calling frame's address.  */
  42 static CORE_ADDR
  43 i386_cygwin_frame_chain (struct frame_info *frame)
  44 {
  45   if (pc_in_dummy_frame (get_frame_pc (frame)))
  46     return get_frame_base (frame);
  47
  48   if (get_frame_type (frame) == SIGTRAMP_FRAME
  49       || i386_frameless_signal_p (frame))
  50     return get_frame_base (frame);
  51
  52   return read_memory_unsigned_integer (get_frame_base (frame), 4);
  53 }
  54
  55 static void
  56 i386_cygwin_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
  57 {
  58   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  59
  60   tdep->struct_return = reg_struct_return;
  61   set_gdbarch_deprecated_frame_chain (gdbarch, i386_cygwin_frame_chain);
  62   set_gdbarch_deprecated_frame_chain_valid (gdbarch, i386_cygwin_frame_chain_valid);
  63 }
  64
  65 static enum gdb_osabi
  66 i386_cygwin_osabi_sniffer (bfd * abfd)
  67 {
  68   char *target_name = bfd_get_target (abfd);
  69
  70   /* Interix also uses pei-i386.
  71      We need a way to distinguish between the two. */
  72   if (strcmp (target_name, "pei-i386") == 0)
  73     return GDB_OSABI_CYGWIN;
  74
  75   return GDB_OSABI_UNKNOWN;
  76 }
  77
  78 void
  79 _initialize_i386_cygwin_tdep (void)
  80 {
  81   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour,
  82                                   i386_cygwin_osabi_sniffer);
  83
  84   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_CYGWIN,
  85                           i386_cygwin_init_abi);
  86 }