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 #ifdef HAVE_PTRACE_GETXFPREGS
  27 #define HAVE_SSE_REGS
  28 #endif
  29
  30 #include "i386/tm-i386.h"
  31 #include "tm-linux.h"
  32
  33 /* Size of sigcontext, from <asm/sigcontext.h>.  */
  34 #define LINUX_SIGCONTEXT_SIZE (88)
  35
  36 /* Offset to saved PC in sigcontext, from <asm/sigcontext.h>.  */
  37 #define LINUX_SIGCONTEXT_PC_OFFSET (56)
  38
  39 /* Offset to saved SP in sigcontext, from <asm/sigcontext.h>.  */
  40 #define LINUX_SIGCONTEXT_SP_OFFSET (28)
  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   (((N) == PC_REGNUM || (N) == FP_REGNUM || (N) == SP_REGNUM)   \
  95    ? lookup_pointer_type (builtin_type_void)                    \
  96    : IS_FP_REGNUM(N) ? builtin_type_long_double                 \
  97    : IS_SSE_REGNUM(N) ? builtin_type_v4sf                       \
  98    : builtin_type_int)
  99
 100 #endif
 101
 102 /* The following works around a problem with /usr/include/sys/procfs.h  */
 103 #define sys_quotactl 1
 104
 105 /* When the i386 Linux kernel calls a signal handler, the return
 106    address points to a bit of code on the stack.  These definitions
 107    are used to identify this bit of code as a signal trampoline in
 108    order to support backtracing through calls to signal handlers.  */
 109
 110 #define I386_LINUX_SIGTRAMP
 111 #define IN_SIGTRAMP(pc, name) ((name) == NULL && i386_linux_sigtramp (pc))
 112
 113 extern int i386_linux_sigtramp PARAMS ((CORE_ADDR));
 114
 115 /* We need our own version of sigtramp_saved_pc to get the saved PC in
 116    a sigtramp routine.  */
 117
 118 #define sigtramp_saved_pc i386_linux_sigtramp_saved_pc
 119 extern CORE_ADDR i386_linux_sigtramp_saved_pc PARAMS ((struct frame_info *));
 120
 121 /* Signal trampolines don't have a meaningful frame.  As in tm-i386.h,
 122    the frame pointer value we use is actually the frame pointer of the
 123    calling frame--that is, the frame which was in progress when the
 124    signal trampoline was entered.  gdb mostly treats this frame
 125    pointer value as a magic cookie.  We detect the case of a signal
 126    trampoline by looking at the SIGNAL_HANDLER_CALLER field, which is
 127    set based on IN_SIGTRAMP.
 128
 129    When a signal trampoline is invoked from a frameless function, we
 130    essentially have two frameless functions in a row.  In this case,
 131    we use the same magic cookie for three frames in a row.  We detect
 132    this case by seeing whether the next frame has
 133    SIGNAL_HANDLER_CALLER set, and, if it does, checking whether the
 134    current frame is actually frameless.  In this case, we need to get
 135    the PC by looking at the SP register value stored in the signal
 136    context.
 137
 138    This should work in most cases except in horrible situations where
 139    a signal occurs just as we enter a function but before the frame
 140    has been set up.  */
 141
 142 #define FRAMELESS_SIGNAL(FRAME)                                 \
 143   ((FRAME)->next != NULL                                        \
 144    && (FRAME)->next->signal_handler_caller                      \
 145    && frameless_look_for_prologue (FRAME))
 146
 147 #undef FRAME_CHAIN
 148 #define FRAME_CHAIN(FRAME)                                      \
 149   ((FRAME)->signal_handler_caller                               \
 150    ? (FRAME)->frame                                             \
 151     : (FRAMELESS_SIGNAL (FRAME)                                 \
 152        ? (FRAME)->frame                                         \
 153        : (!inside_entry_file ((FRAME)->pc)                      \
 154           ? read_memory_integer ((FRAME)->frame, 4)             \
 155           : 0)))
 156
 157 #undef FRAME_SAVED_PC
 158 #define FRAME_SAVED_PC(FRAME)                                   \
 159   ((FRAME)->signal_handler_caller                               \
 160    ? sigtramp_saved_pc (FRAME)                                  \
 161    : (FRAMELESS_SIGNAL (FRAME)                                  \
 162       ? read_memory_integer (i386_linux_sigtramp_saved_sp ((FRAME)->next), 4) \
 163       : read_memory_integer ((FRAME)->frame + 4, 4)))
 164
 165 extern CORE_ADDR i386_linux_sigtramp_saved_sp PARAMS ((struct frame_info *));
 166
 167 /* When we call a function in a shared library, and the PLT sends us
 168    into the dynamic linker to find the function's real address, we
 169    need to skip over the dynamic linker call.  This function decides
 170    when to skip, and where to skip to.  See the comments for
 171    SKIP_SOLIB_RESOLVER at the top of infrun.c.  */
 172 #define SKIP_SOLIB_RESOLVER i386_linux_skip_solib_resolver
 173 extern CORE_ADDR i386_linux_skip_solib_resolver (CORE_ADDR pc);
 174
 175 /* N_FUN symbols in shared libaries have 0 for their values and need
 176    to be relocated. */
 177 #define SOFUN_ADDRESS_MAYBE_MISSING
 178
 179 #endif /* #ifndef TM_LINUX_H */