gdb/ia64-vms-tdep.c

   1 /* Target-dependent code for OpenVMS IA-64.
   2
   3    Copyright (C) 2012-2022 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_inferior ()->top_target (),
  45                      TARGET_OBJECT_OPENVMS_UIB,
  46                      annex + 2, buf, 0, sizeof (buf));
  47
  48   if (res != sizeof (buf))
  49     return -UNW_ENOINFO;
  50
  51   pi->format = UNW_INFO_FORMAT_REMOTE_TABLE;
  52   pi->start_ip = extract_unsigned_integer (buf + 0, 8, byte_order);
  53   pi->end_ip = extract_unsigned_integer (buf + 8, 8, byte_order);
  54   pi->gp = extract_unsigned_integer (buf + 24, 8, byte_order);
  55   table_addr = extract_unsigned_integer (buf + 16, 8, byte_order);
  56
  57   if (table_addr == 0)
  58     {
  59       /* No unwind data.  */
  60       pi->unwind_info = NULL;
  61       pi->unwind_info_size = 0;
  62       return 0;
  63     }
  64
  65   res = target_read_memory (table_addr, buf, 8);
  66   if (res != 0)
  67     return -UNW_ENOINFO;
  68
  69   /* Check version.  */
  70   if (extract_unsigned_integer (buf + 6, 2, byte_order) != 1)
  71     return -UNW_EBADVERSION;
  72   info_len = extract_unsigned_integer (buf + 0, 4, byte_order);
  73   pi->unwind_info_size = 8 * info_len;
  74
  75   /* Read info.  */
  76   pi->unwind_info = xmalloc (pi->unwind_info_size);
  77
  78   res = target_read_memory (table_addr + 8,
  79                             (gdb_byte *) pi->unwind_info, pi->unwind_info_size);
  80   if (res != 0)
  81     {
  82       xfree (pi->unwind_info);
  83       pi->unwind_info = NULL;
  84       return -UNW_ENOINFO;
  85     }
  86
  87   /* FIXME: Handle OSSD (OS Specific Data).  This extension to ia64 unwind
  88      information by OpenVMS is currently not handled by libunwind, but
  89      looks to be used only in very specific context, and is not generated by
  90      GCC.  */
  91
  92   pi->lsda = table_addr + 8 + pi->unwind_info_size;
  93   if (extract_unsigned_integer (buf + 4, 2, byte_order) & 3)
  94     {
  95       pi->lsda += 8;
  96       /* There might be an handler, but this is not used for unwinding.  */
  97       pi->handler = 0;
  98     }
  99
 100   return 0;
 101 }
 102
 103 /* Libunwind callback accessor function for cleanup.  */
 104
 105 static void
 106 ia64_vms_put_unwind_info (unw_addr_space_t as,
 107                           unw_proc_info_t *pip, void *arg)
 108 {
 109   /* Nothing required for now.  */
 110 }
 111
 112 /* Libunwind callback accessor function to get head of the dynamic
 113    unwind-info registration list.  */
 114
 115 static int
 116 ia64_vms_get_dyn_info_list (unw_addr_space_t as,
 117                             unw_word_t *dilap, void *arg)
 118 {
 119   return -UNW_ENOINFO;
 120 }
 121
 122 /* Set of libunwind callback acccessor functions.  */
 123 static unw_accessors_t ia64_vms_unw_accessors;
 124 static unw_accessors_t ia64_vms_unw_rse_accessors;
 125
 126 /* Set of ia64-libunwind-tdep gdb callbacks and data for generic
 127    ia64-libunwind-tdep code to use.  */
 128 static struct libunwind_descr ia64_vms_libunwind_descr;
 129
 130 #endif /* HAVE_LIBUNWIND_IA64_H */
 131
 132 static void
 133 ia64_openvms_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 134 {
 135   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_quad);
 136
 137 #ifdef HAVE_LIBUNWIND_IA64_H
 138   /* Override the default descriptor.  */
 139   ia64_vms_unw_accessors = ia64_unw_accessors;
 140   ia64_vms_unw_accessors.find_proc_info = ia64_vms_find_proc_info_x;
 141   ia64_vms_unw_accessors.put_unwind_info = ia64_vms_put_unwind_info;
 142   ia64_vms_unw_accessors.get_dyn_info_list_addr = ia64_vms_get_dyn_info_list;
 143
 144   ia64_vms_unw_rse_accessors = ia64_unw_rse_accessors;
 145   ia64_vms_unw_rse_accessors.find_proc_info = ia64_vms_find_proc_info_x;
 146   ia64_vms_unw_rse_accessors.put_unwind_info = ia64_vms_put_unwind_info;
 147   ia64_vms_unw_rse_accessors.get_dyn_info_list_addr = ia64_vms_get_dyn_info_list;
 148
 149   ia64_vms_libunwind_descr = ia64_libunwind_descr;
 150   ia64_vms_libunwind_descr.accessors = &ia64_vms_unw_accessors;
 151   ia64_vms_libunwind_descr.special_accessors = &ia64_vms_unw_rse_accessors;
 152
 153   libunwind_frame_set_descr (gdbarch, &ia64_vms_libunwind_descr);
 154 #endif
 155 }
 156
 157 void _initialize_ia64_vms_tdep ();
 158 void
 159 _initialize_ia64_vms_tdep ()
 160 {
 161   gdbarch_register_osabi (bfd_arch_ia64, 0, GDB_OSABI_OPENVMS,
 162                           ia64_openvms_init_abi);
 163 }