gdb/config/i386/tm-i386bsd.h

   1 /* Macro definitions for i386 running under BSD Unix.
   2    Copyright 1986, 1987, 1989, 1991, 1992, 1993 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 /* Override number of expected traps from sysv. */
  21 #define START_INFERIOR_TRAPS_EXPECTED 2
  22
  23 /* Most definitions from sysv could be used. */
  24 #include "i386/tm-i386v.h"
  25
  26 /* 386BSD cannot handle the segment registers. */
  27 /* BSDI can't handle them either.  */
  28 #undef NUM_REGS
  29 #define NUM_REGS 10
  30
  31 /* On 386 bsd, sigtramp is above the user stack and immediately below
  32    the user area. Using constants here allows for cross debugging.
  33    These are tested for BSDI but should work on 386BSD.  */
  34 #define SIGTRAMP_START  0xfdbfdfc0
  35 #define SIGTRAMP_END    0xfdbfe000
  36
  37 /* The following redefines make backtracing through sigtramp work.
  38    They manufacture a fake sigtramp frame and obtain the saved pc in sigtramp
  39    from the sigcontext structure which is pushed by the kernel on the
  40    user stack, along with a pointer to it.  */
  41
  42 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
  43    chain-pointer.
  44    In the case of the i386, the frame's nominal address
  45    is the address of a 4-byte word containing the calling frame's address.  */
  46 #undef FRAME_CHAIN
  47 #define FRAME_CHAIN(thisframe)  \
  48   (thisframe->signal_handler_caller \
  49    ? thisframe->frame \
  50    : (!inside_entry_file ((thisframe)->pc) \
  51       ? read_memory_integer ((thisframe)->frame, 4) \
  52       : 0))
  53
  54 /* A macro that tells us whether the function invocation represented
  55    by FI does not have a frame on the stack associated with it.  If it
  56    does not, FRAMELESS is set to 1, else 0.  */
  57 #undef FRAMELESS_FUNCTION_INVOCATION
  58 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
  59   do { \
  60     if ((FI)->signal_handler_caller) \
  61       (FRAMELESS) = 0; \
  62     else \
  63       (FRAMELESS) = frameless_look_for_prologue(FI); \
  64   } while (0)
  65
  66 /* Saved Pc.  Get it from sigcontext if within sigtramp.  */
  67
  68 /* Offset to saved PC in sigcontext, from <sys/signal.h>.  */
  69 #define SIGCONTEXT_PC_OFFSET 20
  70
  71 #undef FRAME_SAVED_PC
  72 #define FRAME_SAVED_PC(FRAME) \
  73   (((FRAME)->signal_handler_caller \
  74     ? sigtramp_saved_pc (FRAME) \
  75     : read_memory_integer ((FRAME)->frame + 4, 4)) \
  76    )