gdb/ia64-vms-tdep.c

   1 /* Target-dependent code for OpenVMS IA-64.
   2
   3    Copyright (C) 2012-2020 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 #include "gdbarch.h"
  27
  28 #ifdef HAVE_LIBUNWIND_IA64_H
  29
  30 /* Libunwind callback accessor function to acquire procedure unwind-info.  */
  31
  32 static int
  33 ia64_vms_find_proc_info_x (unw_addr_space_t as, unw_word_t ip,
  34                            unw_proc_info_t *pi,
  35                            int need_unwind_info, void *arg)
  36 {
  37   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
  38   gdb_byte buf[32];
  39   const char *annex = core_addr_to_string (ip);
  40   LONGEST res;
  41   CORE_ADDR table_addr;
  42   unsigned int info_len;
  43
  44   res = target_read (current_top_target (), TARGET_OBJECT_OPENVMS_UIB,
  45                      annex + 2, buf, 0, sizeof (buf));
  46
  47   if (res != sizeof (buf))
  48     return -UNW_ENOINFO;
  49
  50   pi->format = UNW_INFO_FORMAT_REMOTE_TABLE;
  51   pi->start_ip = extract_unsigned_integer (buf + 0, 8, byte_order);
  52   pi->end_ip = extract_unsigned_integer (buf + 8, 8, byte_order);
  53   pi->gp = extract_unsigned_integer (buf + 24, 8, byte_order);
  54   table_addr = extract_unsigned_integer (buf + 16, 8, byte_order);
  55
  56   if (table_addr == 0)
  57     {
  58       /* No unwind data.  */
  59       pi->unwind_info = NULL;
  60       pi->unwind_info_size = 0;
  61       return 0;
  62     }
  63
  64   res = target_read_memory (table_addr, buf, 8);
  65   if (res != 0)
  66     return -UNW_ENOINFO;
  67
  68   /* Check version.  */
  69   if (extract_unsigned_integer (buf + 6, 2, byte_order) != 1)
  70     return -UNW_EBADVERSION;
  71   info_len = extract_unsigned_integer (buf + 0, 4, byte_order);
  72   pi->unwind_info_size = 8 * info_len;
  73
  74   /* Read info.  */
  75   pi->unwind_info = xmalloc (pi->unwind_info_size);
  76
  77   res = target_read_memory (table_addr + 8,
  78                             (gdb_byte *) pi->unwind_info, pi->unwind_info_size);
  79   if (res != 0)
  80     {
  81       xfree (pi->unwind_info);
  82       pi->unwind_info = NULL;
  83       return -UNW_ENOINFO;
  84     }
  85
  86   /* FIXME: Handle OSSD (OS Specific Data).  This extension to ia64 unwind
  87      information by OpenVMS is currently not handled by libunwind, but
  88      looks to be used only in very specific context, and is not generated by
  89      GCC.  */
  90
  91   pi->lsda = table_addr + 8 + pi->unwind_info_size;
  92   if (extract_unsigned_integer (buf + 4, 2, byte_order) & 3)
  93     {
  94       pi->lsda += 8;
  95       /* There might be an handler, but this is not used for unwinding.  */
  96       pi->handler = 0;
  97     }
  98
  99   return 0;
 100 }
 101
 102 /* Libunwind callback accessor function for cleanup.  */
 103
 104 static void
 105 ia64_vms_put_unwind_info (unw_addr_space_t as,
 106                           unw_proc_info_t *pip, void *arg)
 107 {
 108   /* Nothing required for now.  */
 109 }
 110
 111 /* Libunwind callback accessor function to get head of the dynamic
 112    unwind-info registration list.  */
 113
 114 static int
 115 ia64_vms_get_dyn_info_list (unw_addr_space_t as,
 116                             unw_word_t *dilap, void *arg)
 117 {
 118   return -UNW_ENOINFO;
 119 }
 120
 121 /* Set of libunwind callback acccessor functions.  */
 122 static unw_accessors_t ia64_vms_unw_accessors;
 123 static unw_accessors_t ia64_vms_unw_rse_accessors;
 124
 125 /* Set of ia64-libunwind-tdep gdb callbacks and data for generic
 126    ia64-libunwind-tdep code to use.  */
 127 static struct libunwind_descr ia64_vms_libunwind_descr;
 128
 129 #endif /* HAVE_LIBUNWIND_IA64_H */
 130
 131 static void
 132 ia64_openvms_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 133 {
 134   set_gdbarch_long_double_format (gdbarch, floatformats_ia64_quad);
 135
 136 #ifdef HAVE_LIBUNWIND_IA64_H
 137   /* Override the default descriptor.  */
 138   ia64_vms_unw_accessors = ia64_unw_accessors;
 139   ia64_vms_unw_accessors.find_proc_info = ia64_vms_find_proc_info_x;
 140   ia64_vms_unw_accessors.put_unwind_info = ia64_vms_put_unwind_info;
 141   ia64_vms_unw_accessors.get_dyn_info_list_addr = ia64_vms_get_dyn_info_list;
 142
 143   ia64_vms_unw_rse_accessors = ia64_unw_rse_accessors;
 144   ia64_vms_unw_rse_accessors.find_proc_info = ia64_vms_find_proc_info_x;
 145   ia64_vms_unw_rse_accessors.put_unwind_info = ia64_vms_put_unwind_info;
 146   ia64_vms_unw_rse_accessors.get_dyn_info_list_addr = ia64_vms_get_dyn_info_list;
 147
 148   ia64_vms_libunwind_descr = ia64_libunwind_descr;
 149   ia64_vms_libunwind_descr.accessors = &ia64_vms_unw_accessors;
 150   ia64_vms_libunwind_descr.special_accessors = &ia64_vms_unw_rse_accessors;
 151
 152   libunwind_frame_set_descr (gdbarch, &ia64_vms_libunwind_descr);
 153 #endif
 154 }
 155
 156 void
 157 _initialize_ia64_vms_tdep (void)
 158 {
 159   gdbarch_register_osabi (bfd_arch_ia64, 0, GDB_OSABI_OPENVMS,
 160                           ia64_openvms_init_abi);
 161 }