gdb/amd64-nat.c

   1 /* Native-dependent code for AMD64.
   2
   3    Copyright (C) 2003, 2004, 2007, 2008 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "gdbarch.h"
  22 #include "regcache.h"
  23
  24 #include "gdb_assert.h"
  25 #include "gdb_string.h"
  26
  27 #include "i386-tdep.h"
  28 #include "amd64-tdep.h"
  29
  30 /* The following bits of code help with implementing debugging 32-bit
  31    code natively on AMD64.  The idea is to define two mappings between
  32    the register number as used by GDB and the register set used by the
  33    host to represent the general-purpose registers; one for 32-bit
  34    code and one for 64-bit code.  The mappings are specified by the
  35    follwing variables and consist of an array of offsets within the
  36    register set indexed by register number, and the number of
  37    registers supported by the mapping.  We don't need mappings for the
  38    floating-point and SSE registers, since the difference between
  39    64-bit and 32-bit variants are negligable.  The difference in the
  40    number of SSE registers is already handled by the target code.  */
  41
  42 /* General-purpose register mapping for native 32-bit code.  */
  43 int *amd64_native_gregset32_reg_offset;
  44 int amd64_native_gregset32_num_regs = I386_NUM_GREGS;
  45
  46 /* General-purpose register mapping for native 64-bit code.  */
  47 int *amd64_native_gregset64_reg_offset;
  48 int amd64_native_gregset64_num_regs = AMD64_NUM_GREGS;
  49
  50 /* Return the offset of REGNUM within the appropriate native
  51    general-purpose register set.  */
  52
  53 static int
  54 amd64_native_gregset_reg_offset (struct gdbarch *gdbarch, int regnum)
  55 {
  56   int *reg_offset = amd64_native_gregset64_reg_offset;
  57   int num_regs = amd64_native_gregset64_num_regs;
  58
  59   gdb_assert (regnum >= 0);
  60
  61   if (gdbarch_ptr_bit (gdbarch) == 32)
  62     {
  63       reg_offset = amd64_native_gregset32_reg_offset;
  64       num_regs = amd64_native_gregset32_num_regs;
  65     }
  66
  67   if (num_regs > gdbarch_num_regs (gdbarch))
  68     num_regs = gdbarch_num_regs (gdbarch);
  69
  70   if (regnum < num_regs && regnum < gdbarch_num_regs (gdbarch))
  71     return reg_offset[regnum];
  72
  73   return -1;
  74 }
  75
  76 /* Return whether the native general-purpose register set supplies
  77    register REGNUM.  */
  78
  79 int
  80 amd64_native_gregset_supplies_p (struct gdbarch *gdbarch, int regnum)
  81 {
  82   return (amd64_native_gregset_reg_offset (gdbarch, regnum) != -1);
  83 }
  84
  85
  86 /* Supply register REGNUM, whose contents are stored in GREGS, to
  87    REGCACHE.  If REGNUM is -1, supply all appropriate registers.  */
  88
  89 void
  90 amd64_supply_native_gregset (struct regcache *regcache,
  91                              const void *gregs, int regnum)
  92 {
  93   const char *regs = gregs;
  94   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  95   int num_regs = amd64_native_gregset64_num_regs;
  96   int i;
  97
  98   if (gdbarch_ptr_bit (gdbarch) == 32)
  99     num_regs = amd64_native_gregset32_num_regs;
 100
 101   if (num_regs > gdbarch_num_regs (gdbarch))
 102     num_regs = gdbarch_num_regs (gdbarch);
 103
 104   for (i = 0; i < num_regs; i++)
 105     {
 106       if (regnum == -1 || regnum == i)
 107         {
 108           int offset = amd64_native_gregset_reg_offset (gdbarch, i);
 109
 110           if (offset != -1)
 111             regcache_raw_supply (regcache, i, regs + offset);
 112         }
 113     }
 114 }
 115
 116 /* Collect register REGNUM from REGCACHE and store its contents in
 117    GREGS.  If REGNUM is -1, collect and store all appropriate
 118    registers.  */
 119
 120 void
 121 amd64_collect_native_gregset (const struct regcache *regcache,
 122                               void *gregs, int regnum)
 123 {
 124   char *regs = gregs;
 125   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 126   int num_regs = amd64_native_gregset64_num_regs;
 127   int i;
 128
 129   if (gdbarch_ptr_bit (gdbarch) == 32)
 130     {
 131       num_regs = amd64_native_gregset32_num_regs;
 132
 133       /* Make sure %eax, %ebx, %ecx, %edx, %esi, %edi, %ebp, %esp and
 134          %eip get zero-extended to 64 bits.  */
 135       for (i = 0; i <= I386_EIP_REGNUM; i++)
 136         {
 137           if (regnum == -1 || regnum == i)
 138             memset (regs + amd64_native_gregset_reg_offset (gdbarch, i), 0, 8);
 139         }
 140       /* Ditto for %cs, %ss, %ds, %es, %fs, and %gs.  */
 141       for (i = I386_CS_REGNUM; i <= I386_GS_REGNUM; i++)
 142         {
 143           if (regnum == -1 || regnum == i)
 144             memset (regs + amd64_native_gregset_reg_offset (gdbarch, i), 0, 8);
 145         }
 146     }
 147
 148   if (num_regs > gdbarch_num_regs (gdbarch))
 149     num_regs = gdbarch_num_regs (gdbarch);
 150
 151   for (i = 0; i < num_regs; i++)
 152     {
 153       if (regnum == -1 || regnum == i)
 154         {
 155           int offset = amd64_native_gregset_reg_offset (gdbarch, i);
 156
 157           if (offset != -1)
 158             regcache_raw_collect (regcache, i, regs + offset);
 159         }
 160     }
 161 }