gdb/config/i386/tm-linux.h

   1 /* Definitions to target GDB to GNU/Linux on 386.
   2    Copyright 1992, 1993, 2000 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,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #ifndef TM_LINUX_H
  22 #define TM_LINUX_H
  23
  24 #define I386_GNULINUX_TARGET
  25 #define HAVE_I387_REGS
  26 #ifdef HAVE_PTRACE_GETFPXREGS
  27 #define HAVE_SSE_REGS
  28 #endif
  29
  30 #include "i386/tm-i386.h"
  31 #include "tm-linux.h"
  32
  33 /* FIXME: kettenis/2000-03-26: We should get rid of this last piece of
  34    Linux-specific `long double'-support code, probably by adding code
  35    to valprint.c:print_floating() to recognize various extended
  36    floating-point formats.  */
  37
  38 #if defined(HAVE_LONG_DOUBLE) && defined(HOST_I386)
  39 /* The host and target are i386 machines and the compiler supports
  40    long doubles. Long doubles on the host therefore have the same
  41    layout as a 387 FPU stack register. */
  42
  43 #define TARGET_ANALYZE_FLOATING                                 \
  44   do                                                            \
  45     {                                                           \
  46       unsigned expon;                                           \
  47                                                                 \
  48       low = extract_unsigned_integer (valaddr, 4);              \
  49       high = extract_unsigned_integer (valaddr + 4, 4);         \
  50       expon = extract_unsigned_integer (valaddr + 8, 2);        \
  51                                                                 \
  52       nonnegative = ((expon & 0x8000) == 0);                    \
  53       is_nan = ((expon & 0x7fff) == 0x7fff)                     \
  54         && ((high & 0x80000000) == 0x80000000)                  \
  55         && (((high & 0x7fffffff) | low) != 0);                  \
  56     }                                                           \
  57   while (0)
  58
  59 #endif
  60
  61 /* The following works around a problem with /usr/include/sys/procfs.h  */
  62 #define sys_quotactl 1
  63
  64 /* When the i386 Linux kernel calls a signal handler, the return
  65    address points to a bit of code on the stack.  These definitions
  66    are used to identify this bit of code as a signal trampoline in
  67    order to support backtracing through calls to signal handlers.  */
  68
  69 #define IN_SIGTRAMP(pc, name) i386_linux_in_sigtramp (pc, name)
  70 extern int i386_linux_in_sigtramp (CORE_ADDR, char *);
  71
  72 /* We need our own version of sigtramp_saved_pc to get the saved PC in
  73    a sigtramp routine.  */
  74
  75 #define sigtramp_saved_pc i386_linux_sigtramp_saved_pc
  76 extern CORE_ADDR i386_linux_sigtramp_saved_pc (struct frame_info *);
  77
  78 /* Signal trampolines don't have a meaningful frame.  As in tm-i386.h,
  79    the frame pointer value we use is actually the frame pointer of the
  80    calling frame--that is, the frame which was in progress when the
  81    signal trampoline was entered.  gdb mostly treats this frame
  82    pointer value as a magic cookie.  We detect the case of a signal
  83    trampoline by looking at the SIGNAL_HANDLER_CALLER field, which is
  84    set based on IN_SIGTRAMP.
  85
  86    When a signal trampoline is invoked from a frameless function, we
  87    essentially have two frameless functions in a row.  In this case,
  88    we use the same magic cookie for three frames in a row.  We detect
  89    this case by seeing whether the next frame has
  90    SIGNAL_HANDLER_CALLER set, and, if it does, checking whether the
  91    current frame is actually frameless.  In this case, we need to get
  92    the PC by looking at the SP register value stored in the signal
  93    context.
  94
  95    This should work in most cases except in horrible situations where
  96    a signal occurs just as we enter a function but before the frame
  97    has been set up.  */
  98
  99 #define FRAMELESS_SIGNAL(FRAME)                                 \
 100   ((FRAME)->next != NULL                                        \
 101    && (FRAME)->next->signal_handler_caller                      \
 102    && frameless_look_for_prologue (FRAME))
 103
 104 #undef FRAME_CHAIN
 105 #define FRAME_CHAIN(FRAME)                                      \
 106   ((FRAME)->signal_handler_caller                               \
 107    ? (FRAME)->frame                                             \
 108     : (FRAMELESS_SIGNAL (FRAME)                                 \
 109        ? (FRAME)->frame                                         \
 110        : (!inside_entry_file ((FRAME)->pc)                      \
 111           ? read_memory_integer ((FRAME)->frame, 4)             \
 112           : 0)))
 113
 114 #undef FRAME_SAVED_PC
 115 #define FRAME_SAVED_PC(FRAME)                                   \
 116   ((FRAME)->signal_handler_caller                               \
 117    ? sigtramp_saved_pc (FRAME)                                  \
 118    : (FRAMELESS_SIGNAL (FRAME)                                  \
 119       ? read_memory_integer (i386_linux_sigtramp_saved_sp ((FRAME)->next), 4) \
 120       : read_memory_integer ((FRAME)->frame + 4, 4)))
 121
 122 extern CORE_ADDR i386_linux_sigtramp_saved_sp (struct frame_info *);
 123
 124 #undef SAVED_PC_AFTER_CALL
 125 #define SAVED_PC_AFTER_CALL(frame) i386_linux_saved_pc_after_call (frame)
 126 extern CORE_ADDR i386_linux_saved_pc_after_call (struct frame_info *);
 127
 128 /* When we call a function in a shared library, and the PLT sends us
 129    into the dynamic linker to find the function's real address, we
 130    need to skip over the dynamic linker call.  This function decides
 131    when to skip, and where to skip to.  See the comments for
 132    SKIP_SOLIB_RESOLVER at the top of infrun.c.  */
 133 #define SKIP_SOLIB_RESOLVER i386_linux_skip_solib_resolver
 134 extern CORE_ADDR i386_linux_skip_solib_resolver (CORE_ADDR pc);
 135
 136 /* N_FUN symbols in shared libaries have 0 for their values and need
 137    to be relocated. */
 138 #define SOFUN_ADDRESS_MAYBE_MISSING
 139 \f
 140
 141 /* Support for longjmp.  */
 142
 143 /* Details about jmp_buf.  It's supposed to be an array of integers.  */
 144
 145 #define JB_ELEMENT_SIZE 4       /* Size of elements in jmp_buf.  */
 146 #define JB_PC           5       /* Array index of saved PC.  */
 147
 148 /* Figure out where the longjmp will land.  Slurp the args out of the
 149    stack.  We expect the first arg to be a pointer to the jmp_buf
 150    structure from which we extract the pc (JB_PC) that we will land
 151    at.  The pc is copied into ADDR.  This routine returns true on
 152    success.  */
 153
 154 #define GET_LONGJMP_TARGET(addr) get_longjmp_target (addr)
 155 extern int get_longjmp_target (CORE_ADDR *addr);
 156
 157 #endif /* #ifndef TM_LINUX_H */