gdb/ia64-vms-tdep.c

   1 /* Target-dependent code for OpenVMS IA-64.
   2
   3    Copyright (C) 2012-2019 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 "frame-unwind.h"
  22 #include "ia64-tdep.h"
  23 #include "osabi.h"
  24 #include "gdbtypes.h"
  25 #include "gdbcore.h"
  26
  27 #ifdef HAVE_LIBUNWIND_IA64_H
  28
  29 /* Libunwind callback accessor function to acquire procedure unwind-info.  */
  30
  31 static int
  32 ia64_vms_find_proc_info_x (unw_addr_space_t as, unw_word_t ip,
  33                            unw_proc_info_t *pi,
  34                            int need_unwind_info, void *arg)
  35 {
  36   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
  37   gdb_byte buf[32];
  38   const char *annex = core_addr_to_string (ip);
  39   LONGEST res;
  40   CORE_ADDR table_addr;
  41   unsigned int info_len;
  42
  43   res = target_read (current_top_target (), TARGET_OBJECT_OPENVMS_UIB,
  44                      annex + 2, buf, 0, sizeof (buf));
  45
  46   if (res != sizeof (buf))
  47     return -UNW_ENOINFO;
  48
  49   pi->format = UNW_INFO_FORMAT_REMOTE_TABLE;
  50   pi->start_ip = extract_unsigned_integer (buf + 0, 8, byte_order);
  51   pi->end_ip = extract_unsigned_integer (buf + 8, 8, byte_order);
  52   pi->gp = extract_unsigned_integer (buf + 24, 8, byte_order);
  53   table_addr = extract_unsigned_integer (buf + 16, 8, byte_order);
  54
  55   if (table_addr == 0)
  56     {
  57       /* No unwind data.  */
  58       pi->unwind_info = NULL;
  59       pi->unwind_info_size = 0;
  60       return 0;
  61     }
  62
  63   res = target_read_memory (table_addr, buf, 8);
  64   if (res != 0)
  65     return -UNW_ENOINFO;
  66
  67   /* Check version.  */
  68   if (extract_unsigned_integer (buf + 6, 2, byte_order) != 1)
  69     return -UNW_EBADVERSION;
  70   info_len = extract_unsigned_integer (buf + 0, 4, byte_order);
  71   pi->unwind_info_size = 8 * info_len;
  72
  73   /* Read info.  */
  74   pi->unwind_info = xmalloc (pi->unwind_info_size);
  75
  76   res = target_read_memory (table_addr + 8,
  77                             (gdb_byte *) pi->unwind_info, pi->unwind_info_size);
  78   if (res != 0)
  79     {
  80       xfree (pi->unwind_info);
  81       pi->unwind_info = NULL;
  82       return -UNW_ENOINFO;
  83     }
  84
  85   /* FIXME: Handle OSSD (OS Specific Data).  This extension to ia64 unwind
  86      information by OpenVMS is currently not handled by libunwind, but
  87      looks to be used only in very specific context, and is not generated by
  88      GCC.  */
  89
  90   pi->lsda = table_addr + 8 + pi->unwind_info_size;
  91   if (extract_unsigned_integer (buf + 4, 2, byte_order) & 3)
  92     {
  93       pi->lsda += 8;
  94       /* There might be an handler, but this is not used for unwinding.  */
  95       pi->handler = 0;
  96     }
  97
  98   return 0;
  99 }
 100
 101 /* Libunwind callback accessor function for cleanup.  */
 102
 103 static void
 104 ia64_vms_put_unwind_info (unw_addr_space_t as,
 105                           unw_proc_info_t *pip, void *arg)
 106 {
 107   /* Nothing required for now.  */
 108 }
 109
 110 /* Libunwind callback accessor function to get head of the dynamic
 111    unwind-info registration list.  */
 112
 113 static int
 114 ia64_vms_get_dyn_info_list (unw_addr_space_t as,
 115                             unw_word_t *dilap, void *arg)
 116 {
 117   return -UNW_ENOINFO;
 118 }
 119
 120 /* Set of libunwind callback acccessor functions.  */
 121 static unw_accessors_t ia64_vms_unw_accessors;
 122 static unw_accessors_t ia64_vms_unw_rse_accessors;
 123
 124 /* Set of ia64-libunwind-tdep gdb callbacks and data for generic
 125    ia64-libunwind-tdep code to use.  */
 126 static struct libunwind_descr ia64_vms_libunwind_descr;
 127
 128 #endif /* HAVE_LIBUNWIND_IA64_H */
 129
 130 static void
 131 ia64_openvms_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 132 {
 133   set_gdbarch_long_double_format (gdbarch, floatformats_ia64_quad);
 134
 135 #ifdef HAVE_LIBUNWIND_IA64_H
 136   /* Override the default descriptor.  */
 137   ia64_vms_unw_accessors = ia64_unw_accessors;
 138   ia64_vms_unw_accessors.find_proc_info = ia64_vms_find_proc_info_x;
 139   ia64_vms_unw_accessors.put_unwind_info = ia64_vms_put_unwind_info;
 140   ia64_vms_unw_accessors.get_dyn_info_list_addr = ia64_vms_get_dyn_info_list;
 141
 142   ia64_vms_unw_rse_accessors = ia64_unw_rse_accessors;
 143   ia64_vms_unw_rse_accessors.find_proc_info = ia64_vms_find_proc_info_x;
 144   ia64_vms_unw_rse_accessors.put_unwind_info = ia64_vms_put_unwind_info;
 145   ia64_vms_unw_rse_accessors.get_dyn_info_list_addr = ia64_vms_get_dyn_info_list;
 146
 147   ia64_vms_libunwind_descr = ia64_libunwind_descr;
 148   ia64_vms_libunwind_descr.accessors = &ia64_vms_unw_accessors;
 149   ia64_vms_libunwind_descr.special_accessors = &ia64_vms_unw_rse_accessors;
 150
 151   libunwind_frame_set_descr (gdbarch, &ia64_vms_libunwind_descr);
 152 #endif
 153 }
 154
 155 void
 156 _initialize_ia64_vms_tdep (void)
 157 {
 158   gdbarch_register_osabi (bfd_arch_ia64, 0, GDB_OSABI_OPENVMS,
 159                           ia64_openvms_init_abi);
 160 }