gdb/i386-darwin-tdep.c

   1 /* Darwin support for GDB, the GNU debugger.
   2    Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2005, 2008, 2009
   3    Free Software Foundation, Inc.
   4
   5    Contributed by Apple Computer, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "frame.h"
  24 #include "inferior.h"
  25 #include "gdbcore.h"
  26 #include "target.h"
  27 #include "floatformat.h"
  28 #include "symtab.h"
  29 #include "regcache.h"
  30 #include "libbfd.h"
  31 #include "objfiles.h"
  32
  33 #include "i387-tdep.h"
  34 #include "i386-tdep.h"
  35 #include "osabi.h"
  36 #include "ui-out.h"
  37 #include "symtab.h"
  38 #include "frame.h"
  39 #include "gdb_assert.h"
  40 #include "i386-darwin-tdep.h"
  41 #include "solib.h"
  42 #include "solib-darwin.h"
  43 #include "dwarf2-frame.h"
  44
  45 /* Offsets into the struct i386_thread_state where we'll find the saved regs.
  46    From <mach/i386/thread_status.h> and i386-tdep.h.  */
  47 int i386_darwin_thread_state_reg_offset[] =
  48 {
  49    0 * 4,   /* EAX */
  50    2 * 4,   /* ECX */
  51    3 * 4,   /* EDX */
  52    1 * 4,   /* EBX */
  53    7 * 4,   /* ESP */
  54    6 * 4,   /* EBP */
  55    5 * 4,   /* ESI */
  56    4 * 4,   /* EDI */
  57   10 * 4,   /* EIP */
  58    9 * 4,   /* EFLAGS */
  59   11 * 4,   /* CS */
  60    8,       /* SS */
  61   12 * 4,   /* DS */
  62   13 * 4,   /* ES */
  63   14 * 4,   /* FS */
  64   15 * 4    /* GS */
  65 };
  66
  67 const int i386_darwin_thread_state_num_regs =
  68   ARRAY_SIZE (i386_darwin_thread_state_reg_offset);
  69
  70 /* Assuming THIS_FRAME is a Darwin sigtramp routine, return the
  71    address of the associated sigcontext structure.  */
  72
  73 static CORE_ADDR
  74 i386_darwin_sigcontext_addr (struct frame_info *this_frame)
  75 {
  76   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  77   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  78   CORE_ADDR bp;
  79   CORE_ADDR si;
  80   gdb_byte buf[4];
  81
  82   get_frame_register (this_frame, I386_EBP_REGNUM, buf);
  83   bp = extract_unsigned_integer (buf, 4, byte_order);
  84
  85   /* A pointer to the ucontext is passed as the fourth argument
  86      to the signal handler.  */
  87   read_memory (bp + 24, buf, 4);
  88   si = extract_unsigned_integer (buf, 4, byte_order);
  89
  90   /* The pointer to mcontext is at offset 28.  */
  91   read_memory (si + 28, buf, 4);
  92
  93   /* First register (eax) is at offset 12.  */
  94   return extract_unsigned_integer (buf, 4, byte_order) + 12;
  95 }
  96
  97 /* Return true if the PC of THIS_FRAME is in a signal trampoline which
  98    may have DWARF-2 CFI.
  99
 100    On Darwin, signal trampolines have DWARF-2 CFI but it has only one FDE
 101    that covers only the indirect call to the user handler.
 102    Without this function, the frame is recognized as a normal frame which is
 103    not expected.  */
 104
 105 int
 106 darwin_dwarf_signal_frame_p (struct gdbarch *gdbarch,
 107                              struct frame_info *this_frame)
 108 {
 109   return i386_sigtramp_p (this_frame);
 110 }
 111
 112 static void
 113 i386_darwin_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 114 {
 115   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 116
 117   /* We support the SSE registers.  */
 118   tdep->num_xmm_regs = I386_NUM_XREGS - 1;
 119   set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS);
 120
 121   dwarf2_frame_set_signal_frame_p (gdbarch, darwin_dwarf_signal_frame_p);
 122
 123   tdep->struct_return = reg_struct_return;
 124
 125   tdep->sigtramp_p = i386_sigtramp_p;
 126   tdep->sigcontext_addr = i386_darwin_sigcontext_addr;
 127   tdep->sc_reg_offset = i386_darwin_thread_state_reg_offset;
 128   tdep->sc_num_regs = i386_darwin_thread_state_num_regs;
 129
 130   tdep->jb_pc_offset = 20;
 131
 132   set_solib_ops (gdbarch, &darwin_so_ops);
 133 }
 134
 135 static enum gdb_osabi
 136 i386_mach_o_osabi_sniffer (bfd *abfd)
 137 {
 138   if (!bfd_check_format (abfd, bfd_object))
 139     return GDB_OSABI_UNKNOWN;
 140
 141   if (bfd_get_arch (abfd) == bfd_arch_i386)
 142     return GDB_OSABI_DARWIN;
 143
 144   return GDB_OSABI_UNKNOWN;
 145 }
 146
 147 void
 148 _initialize_i386_darwin_tdep (void)
 149 {
 150   gdbarch_register_osabi_sniffer (bfd_arch_unknown, bfd_target_mach_o_flavour,
 151                                   i386_mach_o_osabi_sniffer);
 152
 153   gdbarch_register_osabi (bfd_arch_i386, bfd_mach_i386_i386,
 154                           GDB_OSABI_DARWIN, i386_darwin_init_abi);
 155 }