gdb/config/i386/tm-linux.h

   1 /* Definitions to target GDB to GNU/Linux on 386.
   2    Copyright 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., 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
  27 #include "i386/tm-i386.h"
  28
  29 /* Size of sigcontext, from <asm/sigcontext.h>.  */
  30 #define LINUX_SIGCONTEXT_SIZE (88)
  31
  32 /* Offset to saved PC in sigcontext, from <asm/sigcontext.h>.  */
  33 #define LINUX_SIGCONTEXT_PC_OFFSET (56)
  34
  35 /* Offset to saved SP in sigcontext, from <asm/sigcontext.h>.  */
  36 #define LINUX_SIGCONTEXT_SP_OFFSET (28)
  37
  38 /* We need this file for the SOLIB_TRAMPOLINE stuff. */
  39
  40 #include "tm-sysv4.h"
  41
  42 #define LOW_RETURN_REGNUM 0     /* holds low four bytes of result */
  43 #define HIGH_RETURN_REGNUM 2    /* holds high four bytes of result */
  44
  45 /* This should probably move to tm-i386.h.  */
  46 #define TARGET_LONG_DOUBLE_BIT 80
  47
  48 #if defined(HAVE_LONG_DOUBLE) && defined(HOST_I386)
  49 /* The host and target are i386 machines and the compiler supports
  50    long doubles. Long doubles on the host therefore have the same
  51    layout as a 387 FPU stack register. */
  52 #define LD_I387
  53
  54 extern int i387_extract_floating (PTR addr, int len, long double *dretptr);
  55 extern int i387_store_floating   (PTR addr, int len, long double val);
  56
  57 #define TARGET_EXTRACT_FLOATING i387_extract_floating
  58 #define TARGET_STORE_FLOATING   i387_store_floating
  59
  60 #define TARGET_ANALYZE_FLOATING                                 \
  61   do                                                            \
  62     {                                                           \
  63       unsigned expon;                                           \
  64                                                                 \
  65       low = extract_unsigned_integer (valaddr, 4);              \
  66       high = extract_unsigned_integer (valaddr + 4, 4);         \
  67       expon = extract_unsigned_integer (valaddr + 8, 2);        \
  68                                                                 \
  69       nonnegative = ((expon & 0x8000) == 0);                    \
  70       is_nan = ((expon & 0x7fff) == 0x7fff)                     \
  71         && ((high & 0x80000000) == 0x80000000)                  \
  72         && (((high & 0x7fffffff) | low) != 0);                  \
  73     }                                                           \
  74   while (0)
  75
  76 #undef REGISTER_CONVERT_TO_VIRTUAL
  77 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO)        \
  78 {                                                               \
  79   long double val = *((long double *)FROM);                     \
  80   store_floating ((TO), TYPE_LENGTH (TYPE), val);               \
  81 }
  82
  83 #undef REGISTER_CONVERT_TO_RAW
  84 #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO)                    \
  85 {                                                                       \
  86   long double val = extract_floating ((FROM), TYPE_LENGTH (TYPE));      \
  87   *((long double *)TO) = val;                                           \
  88 }
  89
  90 /* Return the GDB type object for the "standard" data type
  91    of data in register N.  */
  92 #undef REGISTER_VIRTUAL_TYPE
  93 #define REGISTER_VIRTUAL_TYPE(N)                                        \
  94   (IS_FP_REGNUM (N) ? builtin_type_long_double : builtin_type_int)
  95
  96 #endif
  97
  98 /* The following works around a problem with /usr/include/sys/procfs.h  */
  99 #define sys_quotactl 1
 100
 101 /* When the i386 Linux kernel calls a signal handler, the return
 102    address points to a bit of code on the stack.  These definitions
 103    are used to identify this bit of code as a signal trampoline in
 104    order to support backtracing through calls to signal handlers.  */
 105
 106 #define I386_LINUX_SIGTRAMP
 107 #define IN_SIGTRAMP(pc, name) ((name) == NULL && i386_linux_sigtramp (pc))
 108
 109 extern int i386_linux_sigtramp PARAMS ((CORE_ADDR));
 110
 111 /* We need our own version of sigtramp_saved_pc to get the saved PC in
 112    a sigtramp routine.  */
 113
 114 #define sigtramp_saved_pc i386_linux_sigtramp_saved_pc
 115 extern CORE_ADDR i386_linux_sigtramp_saved_pc PARAMS ((struct frame_info *));
 116
 117 /* Signal trampolines don't have a meaningful frame.  As in tm-i386.h,
 118    the frame pointer value we use is actually the frame pointer of the
 119    calling frame--that is, the frame which was in progress when the
 120    signal trampoline was entered.  gdb mostly treats this frame
 121    pointer value as a magic cookie.  We detect the case of a signal
 122    trampoline by looking at the SIGNAL_HANDLER_CALLER field, which is
 123    set based on IN_SIGTRAMP.
 124
 125    When a signal trampoline is invoked from a frameless function, we
 126    essentially have two frameless functions in a row.  In this case,
 127    we use the same magic cookie for three frames in a row.  We detect
 128    this case by seeing whether the next frame has
 129    SIGNAL_HANDLER_CALLER set, and, if it does, checking whether the
 130    current frame is actually frameless.  In this case, we need to get
 131    the PC by looking at the SP register value stored in the signal
 132    context.
 133
 134    This should work in most cases except in horrible situations where
 135    a signal occurs just as we enter a function but before the frame
 136    has been set up.  */
 137
 138 #define FRAMELESS_SIGNAL(FRAME)                                 \
 139   ((FRAME)->next != NULL                                        \
 140    && (FRAME)->next->signal_handler_caller                      \
 141    && frameless_look_for_prologue (FRAME))
 142
 143 #undef FRAME_CHAIN
 144 #define FRAME_CHAIN(FRAME)                                      \
 145   ((FRAME)->signal_handler_caller                               \
 146    ? (FRAME)->frame                                             \
 147     : (FRAMELESS_SIGNAL (FRAME)                                 \
 148        ? (FRAME)->frame                                         \
 149        : (!inside_entry_file ((FRAME)->pc)                      \
 150           ? read_memory_integer ((FRAME)->frame, 4)             \
 151           : 0)))
 152
 153 #undef FRAME_SAVED_PC
 154 #define FRAME_SAVED_PC(FRAME)                                   \
 155   ((FRAME)->signal_handler_caller                               \
 156    ? sigtramp_saved_pc (FRAME)                                  \
 157    : (FRAMELESS_SIGNAL (FRAME)                                  \
 158       ? read_memory_integer (i386_linux_sigtramp_saved_sp ((FRAME)->next), 4) \
 159       : read_memory_integer ((FRAME)->frame + 4, 4)))
 160
 161 extern CORE_ADDR i386_linux_sigtramp_saved_sp PARAMS ((struct frame_info *));
 162
 163 /* Some versions of Linux have real-time signal support in the C library, and
 164    some don't.  We have to include this file to find out.  */
 165 #include <signal.h>
 166
 167 #ifdef __SIGRTMIN
 168 #define REALTIME_LO __SIGRTMIN
 169 #define REALTIME_HI (__SIGRTMAX + 1)
 170 #else
 171 #define REALTIME_LO 32
 172 #define REALTIME_HI 64
 173 #endif
 174
 175 /* When we call a function in a shared library, and the PLT sends us
 176    into the dynamic linker to find the function's real address, we
 177    need to skip over the dynamic linker call.  This function decides
 178    when to skip, and where to skip to.  See the comments for
 179    SKIP_SOLIB_RESOLVER at the top of infrun.c.  */
 180 #define SKIP_SOLIB_RESOLVER i386_linux_skip_solib_resolver
 181 extern CORE_ADDR i386_linux_skip_solib_resolver (CORE_ADDR pc);
 182
 183 /* N_FUN symbols in shared libaries have 0 for their values and need
 184    to be relocated. */
 185 #define SOFUN_ADDRESS_MAYBE_MISSING
 186
 187 #endif /* #ifndef TM_LINUX_H */