aboutsummaryrefslogtreecommitdiff
path: root/gdb/gnu-nat.h
AgeCommit message (Expand)AuthorFilesLines
2022-01-01Automatic Copyright Year update after running gdb/copyright.pyJoel Brobecker1-1/+1
2021-05-27gdb: fix tab after space indentation issuesSimon Marchi1-2/+2
2021-01-01Update copyright year range in all GDB filesJoel Brobecker1-1/+1
2020-11-02gdb, gdbserver, gdbsupport: fix leading space vs tabs issuesSimon Marchi1-1/+1
2020-09-18Make target_wait options use enum flagsTom Tromey1-1/+1
2020-05-31gnu-nat: Move local functions inside gnu_nat_target classSamuel Thibault1-6/+43
2020-05-30hurd: add gnu_target pointer to fix thread API callsSamuel Thibault1-0/+3
2020-05-30hurd: fix gnu_debug_flag typeSamuel Thibault1-1/+1
2020-01-01Update copyright year range in all GDB files.Joel Brobecker1-1/+1
2019-03-13Change pid_to_str to return std::stringTom Tromey1-1/+1
2019-02-14[gdb, hurd] Repair build after "Convert struct target_ops to C++" changesThomas Schwinge1-0/+2
2019-02-14[gdb, hurd] Work around conflict between Mach's 'thread_info' function, and G...Thomas Schwinge1-1/+14
2019-02-07Normalize include guards in gdbTom Tromey1-3/+3
2019-01-01Update copyright year range in all GDB files.Joel Brobecker1-1/+1
2018-05-03target_ops: Use bool throughoutPedro Alves1-1/+1
2018-05-03Convert struct target_ops to C++Pedro Alves1-3/+31
2018-01-02Update copyright year range in all GDB filesJoel Brobecker1-1/+1
2017-01-01update copyright year range in GDB filesJoel Brobecker1-1/+1
2016-01-01GDB copyright headers update after running GDB's copyright.py script.Joel Brobecker1-1/+1
2015-01-01Update year range in copyright notice of all files owned by the GDB project.Joel Brobecker1-1/+1
2014-09-16Add hardware watchpoint support for x86 GNU Hurd.Samuel Thibault1-0/+5
2014-01-01Update Copyright year range in all files maintained by GDB.Joel Brobecker1-1/+1
2013-01-01Update years in copyright notice for the GDB files.Joel Brobecker1-2/+1
2012-01-04Copyright year update in most files of the GDB Project.Joel Brobecker1-2/+2
2011-01-072011-01-07 Michael Snyder <msnyder@vmware.com>Michael Snyder1-8/+9
2011-01-01run copyright.sh for 2011.Joel Brobecker1-1/+1
2010-01-01Update copyright year in most headers.Joel Brobecker1-1/+1
2009-07-20 * gnu-nat.c: Include "inf-child.h".Pedro Alves1-0/+4
2009-04-21 * gnu-nat.h (proc_debug): Add missing continuation line in macro.Pierre Muller1-1/+1
2009-04-17 ARI fix: Do not use %p, replace by call to host_address_to_stringPierre Muller1-2/+3
2009-01-03 Updated copyright notices for most files.Joel Brobecker1-1/+1
2008-10-07 * gnu-nat.h: Rename `current_inferior' to `gnu_current_inf' toPedro Alves1-1/+1
2008-01-01 Updated copyright notices for most files.Daniel Jacobowitz1-1/+1
2007-08-23 Switch the license of all .c files to GPLv3.Joel Brobecker1-11/+9
2007-01-09Copyright updates for 2007.Daniel Jacobowitz1-1/+2
2005-12-17 * breakpoint.c:Eli Zaretskii1-3/+3
2002-09-29Zap __FUNCTION__.Andrew Cagney1-1/+1
2001-03-06Update/correct copyright notices.Kevin Buettner1-1/+1
2000-02-01import gdb-2000-01-31 snapshotJason Molenda1-0/+10
1999-07-07import gdb-1999-07-07 post reformatJason Molenda1-38/+39
1999-07-07import gdb-1999-07-07 pre reformatJason Molenda1-1/+1
1999-04-26import gdb-19990422 snapshotStan Shebs1-4/+1
1999-04-16Initial creation of sourceware repositorygdb-4_18-branchpointStan Shebs1-0/+93
1999-04-16Initial creation of sourceware repositoryStan Shebs1-93/+0
1999-01-111999-01-11 Jason Molenda (jsm@bugshack.cygnus.com)Jason Molenda1-13/+12
1997-04-29Mon Apr 28 21:25:32 1997 Michael Snyder <msnyder@cleaver.cygnus.com>Michael Snyder1-2/+3
1996-07-17Changes from the FSF for Hurd thread support.Stu Grossman1-1/+3
1996-04-08 From: Miles Bader <miles@gnu.ai.mit.edu>Fred Fish1-0/+91
#n636'>636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336
/* Low level packing and unpacking of values for GDB, the GNU Debugger.

   Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
   1995, 1996, 1997, 1998, 1999, 2000, 2002, 2003 Free Software
   Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "gdb_string.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "value.h"
#include "gdbcore.h"
#include "command.h"
#include "gdbcmd.h"
#include "target.h"
#include "language.h"
#include "scm-lang.h"
#include "demangle.h"
#include "doublest.h"
#include "gdb_assert.h"
#include "regcache.h"
#include "block.h"

/* Prototypes for exported functions. */

void _initialize_values (void);

/* Prototypes for local functions. */

static void show_values (char *, int);

static void show_convenience (char *, int);


/* The value-history records all the values printed
   by print commands during this session.  Each chunk
   records 60 consecutive values.  The first chunk on
   the chain records the most recent values.
   The total number of values is in value_history_count.  */

#define VALUE_HISTORY_CHUNK 60

struct value_history_chunk
  {
    struct value_history_chunk *next;
    struct value *values[VALUE_HISTORY_CHUNK];
  };

/* Chain of chunks now in use.  */

static struct value_history_chunk *value_history_chain;

static int value_history_count;	/* Abs number of last entry stored */

/* List of all value objects currently allocated
   (except for those released by calls to release_value)
   This is so they can be freed after each command.  */

static struct value *all_values;

/* Allocate a  value  that has the correct length for type TYPE.  */

struct value *
allocate_value (struct type *type)
{
  struct value *val;
  struct type *atype = check_typedef (type);

  val = (struct value *) xmalloc (sizeof (struct value) + TYPE_LENGTH (atype));
  VALUE_NEXT (val) = all_values;
  all_values = val;
  VALUE_TYPE (val) = type;
  VALUE_ENCLOSING_TYPE (val) = type;
  VALUE_LVAL (val) = not_lval;
  VALUE_ADDRESS (val) = 0;
  VALUE_FRAME_ID (val) = null_frame_id;
  VALUE_OFFSET (val) = 0;
  VALUE_BITPOS (val) = 0;
  VALUE_BITSIZE (val) = 0;
  VALUE_REGNO (val) = -1;
  VALUE_LAZY (val) = 0;
  VALUE_OPTIMIZED_OUT (val) = 0;
  VALUE_BFD_SECTION (val) = NULL;
  VALUE_EMBEDDED_OFFSET (val) = 0;
  VALUE_POINTED_TO_OFFSET (val) = 0;
  val->modifiable = 1;
  return val;
}

/* Allocate a  value  that has the correct length
   for COUNT repetitions type TYPE.  */

struct value *
allocate_repeat_value (struct type *type, int count)
{
  int low_bound = current_language->string_lower_bound;		/* ??? */
  /* FIXME-type-allocation: need a way to free this type when we are
     done with it.  */
  struct type *range_type
  = create_range_type ((struct type *) NULL, builtin_type_int,
		       low_bound, count + low_bound - 1);
  /* FIXME-type-allocation: need a way to free this type when we are
     done with it.  */
  return allocate_value (create_array_type ((struct type *) NULL,
					    type, range_type));
}

/* Return a mark in the value chain.  All values allocated after the
   mark is obtained (except for those released) are subject to being freed
   if a subsequent value_free_to_mark is passed the mark.  */
struct value *
value_mark (void)
{
  return all_values;
}

/* Free all values allocated since MARK was obtained by value_mark
   (except for those released).  */
void
value_free_to_mark (struct value *mark)
{
  struct value *val;
  struct value *next;

  for (val = all_values; val && val != mark; val = next)
    {
      next = VALUE_NEXT (val);
      value_free (val);
    }
  all_values = val;
}

/* Free all the values that have been allocated (except for those released).
   Called after each command, successful or not.  */

void
free_all_values (void)
{
  struct value *val;
  struct value *next;

  for (val = all_values; val; val = next)
    {
      next = VALUE_NEXT (val);
      value_free (val);
    }

  all_values = 0;
}

/* Remove VAL from the chain all_values
   so it will not be freed automatically.  */

void
release_value (struct value *val)
{
  struct value *v;

  if (all_values == val)
    {
      all_values = val->next;
      return;
    }

  for (v = all_values; v; v = v->next)
    {
      if (v->next == val)
	{
	  v->next = val->next;
	  break;
	}
    }
}

/* Release all values up to mark  */
struct value *
value_release_to_mark (struct value *mark)
{
  struct value *val;
  struct value *next;

  for (val = next = all_values; next; next = VALUE_NEXT (next))
    if (VALUE_NEXT (next) == mark)
      {
	all_values = VALUE_NEXT (next);
	VALUE_NEXT (next) = 0;
	return val;
      }
  all_values = 0;
  return val;
}

/* Return a copy of the value ARG.
   It contains the same contents, for same memory address,
   but it's a different block of storage.  */

struct value *
value_copy (struct value *arg)
{
  register struct type *encl_type = VALUE_ENCLOSING_TYPE (arg);
  struct value *val = allocate_value (encl_type);
  VALUE_TYPE (val) = VALUE_TYPE (arg);
  VALUE_LVAL (val) = VALUE_LVAL (arg);
  VALUE_ADDRESS (val) = VALUE_ADDRESS (arg);
  VALUE_OFFSET (val) = VALUE_OFFSET (arg);
  VALUE_BITPOS (val) = VALUE_BITPOS (arg);
  VALUE_BITSIZE (val) = VALUE_BITSIZE (arg);
  VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg);
  VALUE_REGNO (val) = VALUE_REGNO (arg);
  VALUE_LAZY (val) = VALUE_LAZY (arg);
  VALUE_OPTIMIZED_OUT (val) = VALUE_OPTIMIZED_OUT (arg);
  VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (arg);
  VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (arg);
  VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (arg);
  val->modifiable = arg->modifiable;
  if (!VALUE_LAZY (val))
    {
      memcpy (VALUE_CONTENTS_ALL_RAW (val), VALUE_CONTENTS_ALL_RAW (arg),
	      TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg)));

    }
  return val;
}

/* Access to the value history.  */

/* Record a new value in the value history.
   Returns the absolute history index of the entry.
   Result of -1 indicates the value was not saved; otherwise it is the
   value history index of this new item.  */

int
record_latest_value (struct value *val)
{
  int i;

  /* We don't want this value to have anything to do with the inferior anymore.
     In particular, "set $1 = 50" should not affect the variable from which
     the value was taken, and fast watchpoints should be able to assume that
     a value on the value history never changes.  */
  if (VALUE_LAZY (val))
    value_fetch_lazy (val);
  /* We preserve VALUE_LVAL so that the user can find out where it was fetched
     from.  This is a bit dubious, because then *&$1 does not just return $1
     but the current contents of that location.  c'est la vie...  */
  val->modifiable = 0;
  release_value (val);

  /* Here we treat value_history_count as origin-zero
     and applying to the value being stored now.  */

  i = value_history_count % VALUE_HISTORY_CHUNK;
  if (i == 0)
    {
      struct value_history_chunk *new
      = (struct value_history_chunk *)
      xmalloc (sizeof (struct value_history_chunk));
      memset (new->values, 0, sizeof new->values);
      new->next = value_history_chain;
      value_history_chain = new;
    }

  value_history_chain->values[i] = val;

  /* Now we regard value_history_count as origin-one
     and applying to the value just stored.  */

  return ++value_history_count;
}

/* Return a copy of the value in the history with sequence number NUM.  */

struct value *
access_value_history (int num)
{
  struct value_history_chunk *chunk;
  register int i;
  register int absnum = num;

  if (absnum <= 0)
    absnum += value_history_count;

  if (absnum <= 0)
    {
      if (num == 0)
	error ("The history is empty.");
      else if (num == 1)
	error ("There is only one value in the history.");
      else
	error ("History does not go back to $$%d.", -num);
    }
  if (absnum > value_history_count)
    error ("History has not yet reached $%d.", absnum);

  absnum--;

  /* Now absnum is always absolute and origin zero.  */

  chunk = value_history_chain;
  for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK;
       i > 0; i--)
    chunk = chunk->next;

  return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]);
}

/* Clear the value history entirely.
   Must be done when new symbol tables are loaded,
   because the type pointers become invalid.  */

void
clear_value_history (void)
{
  struct value_history_chunk *next;
  register int i;
  struct value *val;

  while (value_history_chain)
    {
      for (i = 0; i < VALUE_HISTORY_CHUNK; i++)
	if ((val = value_history_chain->values[i]) != NULL)
	  xfree (val);
      next = value_history_chain->next;
      xfree (value_history_chain);
      value_history_chain = next;
    }
  value_history_count = 0;
}

static void
show_values (char *num_exp, int from_tty)
{
  register int i;
  struct value *val;
  static int num = 1;

  if (num_exp)
    {
      /* "info history +" should print from the stored position.
         "info history <exp>" should print around value number <exp>.  */
      if (num_exp[0] != '+' || num_exp[1] != '\0')
	num = parse_and_eval_long (num_exp) - 5;
    }
  else
    {
      /* "info history" means print the last 10 values.  */
      num = value_history_count - 9;
    }

  if (num <= 0)
    num = 1;

  for (i = num; i < num + 10 && i <= value_history_count; i++)
    {
      val = access_value_history (i);
      printf_filtered ("$%d = ", i);
      value_print (val, gdb_stdout, 0, Val_pretty_default);
      printf_filtered ("\n");
    }

  /* The next "info history +" should start after what we just printed.  */
  num += 10;

  /* Hitting just return after this command should do the same thing as
     "info history +".  If num_exp is null, this is unnecessary, since
     "info history +" is not useful after "info history".  */
  if (from_tty && num_exp)
    {
      num_exp[0] = '+';
      num_exp[1] = '\0';
    }
}

/* Internal variables.  These are variables within the debugger
   that hold values assigned by debugger commands.
   The user refers to them with a '$' prefix
   that does not appear in the variable names stored internally.  */

static struct internalvar *internalvars;

/* Look up an internal variable with name NAME.  NAME should not
   normally include a dollar sign.

   If the specified internal variable does not exist,
   one is created, with a void value.  */

struct internalvar *
lookup_internalvar (char *name)
{
  register struct internalvar *var;

  for (var = internalvars; var; var = var->next)
    if (strcmp (var->name, name) == 0)
      return var;

  var = (struct internalvar *) xmalloc (sizeof (struct internalvar));
  var->name = concat (name, NULL);
  var->value = allocate_value (builtin_type_void);
  release_value (var->value);
  var->next = internalvars;
  internalvars = var;
  return var;
}

struct value *
value_of_internalvar (struct internalvar *var)
{
  struct value *val;

  val = value_copy (var->value);
  if (VALUE_LAZY (val))
    value_fetch_lazy (val);
  VALUE_LVAL (val) = lval_internalvar;
  VALUE_INTERNALVAR (val) = var;
  return val;
}

void
set_internalvar_component (struct internalvar *var, int offset, int bitpos,
			   int bitsize, struct value *newval)
{
  register char *addr = VALUE_CONTENTS (var->value) + offset;

  if (bitsize)
    modify_field (addr, value_as_long (newval),
		  bitpos, bitsize);
  else
    memcpy (addr, VALUE_CONTENTS (newval), TYPE_LENGTH (VALUE_TYPE (newval)));
}

void
set_internalvar (struct internalvar *var, struct value *val)
{
  struct value *newval;

  newval = value_copy (val);
  newval->modifiable = 1;

  /* Force the value to be fetched from the target now, to avoid problems
     later when this internalvar is referenced and the target is gone or
     has changed.  */
  if (VALUE_LAZY (newval))
    value_fetch_lazy (newval);

  /* Begin code which must not call error().  If var->value points to
     something free'd, an error() obviously leaves a dangling pointer.
     But we also get a danling pointer if var->value points to
     something in the value chain (i.e., before release_value is
     called), because after the error free_all_values will get called before
     long.  */
  xfree (var->value);
  var->value = newval;
  release_value (newval);
  /* End code which must not call error().  */
}

char *
internalvar_name (struct internalvar *var)
{
  return var->name;
}

/* Free all internalvars.  Done when new symtabs are loaded,
   because that makes the values invalid.  */

void
clear_internalvars (void)
{
  register struct internalvar *var;

  while (internalvars)
    {
      var = internalvars;
      internalvars = var->next;
      xfree (var->name);
      xfree (var->value);
      xfree (var);
    }
}

static void
show_convenience (char *ignore, int from_tty)
{
  register struct internalvar *var;
  int varseen = 0;

  for (var = internalvars; var; var = var->next)
    {
      if (!varseen)
	{
	  varseen = 1;
	}
      printf_filtered ("$%s = ", var->name);
      value_print (var->value, gdb_stdout, 0, Val_pretty_default);
      printf_filtered ("\n");
    }
  if (!varseen)
    printf_unfiltered ("No debugger convenience variables now defined.\n\
Convenience variables have names starting with \"$\";\n\
use \"set\" as in \"set $foo = 5\" to define them.\n");
}

/* Extract a value as a C number (either long or double).
   Knows how to convert fixed values to double, or
   floating values to long.
   Does not deallocate the value.  */

LONGEST
value_as_long (struct value *val)
{
  /* This coerces arrays and functions, which is necessary (e.g.
     in disassemble_command).  It also dereferences references, which
     I suspect is the most logical thing to do.  */
  COERCE_ARRAY (val);
  return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val));
}

DOUBLEST
value_as_double (struct value *val)
{
  DOUBLEST foo;
  int inv;

  foo = unpack_double (VALUE_TYPE (val), VALUE_CONTENTS (val), &inv);
  if (inv)
    error ("Invalid floating value found in program.");
  return foo;
}
/* Extract a value as a C pointer. Does not deallocate the value.  
   Note that val's type may not actually be a pointer; value_as_long
   handles all the cases.  */
CORE_ADDR
value_as_address (struct value *val)
{
  /* Assume a CORE_ADDR can fit in a LONGEST (for now).  Not sure
     whether we want this to be true eventually.  */
#if 0
  /* ADDR_BITS_REMOVE is wrong if we are being called for a
     non-address (e.g. argument to "signal", "info break", etc.), or
     for pointers to char, in which the low bits *are* significant.  */
  return ADDR_BITS_REMOVE (value_as_long (val));
#else

  /* There are several targets (IA-64, PowerPC, and others) which
     don't represent pointers to functions as simply the address of
     the function's entry point.  For example, on the IA-64, a
     function pointer points to a two-word descriptor, generated by
     the linker, which contains the function's entry point, and the
     value the IA-64 "global pointer" register should have --- to
     support position-independent code.  The linker generates
     descriptors only for those functions whose addresses are taken.

     On such targets, it's difficult for GDB to convert an arbitrary
     function address into a function pointer; it has to either find
     an existing descriptor for that function, or call malloc and
     build its own.  On some targets, it is impossible for GDB to
     build a descriptor at all: the descriptor must contain a jump
     instruction; data memory cannot be executed; and code memory
     cannot be modified.

     Upon entry to this function, if VAL is a value of type `function'
     (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
     VALUE_ADDRESS (val) is the address of the function.  This is what
     you'll get if you evaluate an expression like `main'.  The call
     to COERCE_ARRAY below actually does all the usual unary
     conversions, which includes converting values of type `function'
     to `pointer to function'.  This is the challenging conversion
     discussed above.  Then, `unpack_long' will convert that pointer
     back into an address.

     So, suppose the user types `disassemble foo' on an architecture
     with a strange function pointer representation, on which GDB
     cannot build its own descriptors, and suppose further that `foo'
     has no linker-built descriptor.  The address->pointer conversion
     will signal an error and prevent the command from running, even
     though the next step would have been to convert the pointer
     directly back into the same address.

     The following shortcut avoids this whole mess.  If VAL is a
     function, just return its address directly.  */
  if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC
      || TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_METHOD)
    return VALUE_ADDRESS (val);

  COERCE_ARRAY (val);

  /* Some architectures (e.g. Harvard), map instruction and data
     addresses onto a single large unified address space.  For
     instance: An architecture may consider a large integer in the
     range 0x10000000 .. 0x1000ffff to already represent a data
     addresses (hence not need a pointer to address conversion) while
     a small integer would still need to be converted integer to
     pointer to address.  Just assume such architectures handle all
     integer conversions in a single function.  */

  /* JimB writes:

     I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
     must admonish GDB hackers to make sure its behavior matches the
     compiler's, whenever possible.

     In general, I think GDB should evaluate expressions the same way
     the compiler does.  When the user copies an expression out of
     their source code and hands it to a `print' command, they should
     get the same value the compiler would have computed.  Any
     deviation from this rule can cause major confusion and annoyance,
     and needs to be justified carefully.  In other words, GDB doesn't
     really have the freedom to do these conversions in clever and
     useful ways.

     AndrewC pointed out that users aren't complaining about how GDB
     casts integers to pointers; they are complaining that they can't
     take an address from a disassembly listing and give it to `x/i'.
     This is certainly important.

     Adding an architecture method like INTEGER_TO_ADDRESS certainly
     makes it possible for GDB to "get it right" in all circumstances
     --- the target has complete control over how things get done, so
     people can Do The Right Thing for their target without breaking
     anyone else.  The standard doesn't specify how integers get
     converted to pointers; usually, the ABI doesn't either, but
     ABI-specific code is a more reasonable place to handle it.  */

  if (TYPE_CODE (VALUE_TYPE (val)) != TYPE_CODE_PTR
      && TYPE_CODE (VALUE_TYPE (val)) != TYPE_CODE_REF
      && INTEGER_TO_ADDRESS_P ())
    return INTEGER_TO_ADDRESS (VALUE_TYPE (val), VALUE_CONTENTS (val));

  return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val));
#endif
}

/* Unpack raw data (copied from debugee, target byte order) at VALADDR
   as a long, or as a double, assuming the raw data is described
   by type TYPE.  Knows how to convert different sizes of values
   and can convert between fixed and floating point.  We don't assume
   any alignment for the raw data.  Return value is in host byte order.

   If you want functions and arrays to be coerced to pointers, and
   references to be dereferenced, call value_as_long() instead.

   C++: It is assumed that the front-end has taken care of
   all matters concerning pointers to members.  A pointer
   to member which reaches here is considered to be equivalent
   to an INT (or some size).  After all, it is only an offset.  */

LONGEST
unpack_long (struct type *type, const char *valaddr)
{
  register enum type_code code = TYPE_CODE (type);
  register int len = TYPE_LENGTH (type);
  register int nosign = TYPE_UNSIGNED (type);

  if (current_language->la_language == language_scm
      && is_scmvalue_type (type))
    return scm_unpack (type, valaddr, TYPE_CODE_INT);

  switch (code)
    {
    case TYPE_CODE_TYPEDEF:
      return unpack_long (check_typedef (type), valaddr);
    case TYPE_CODE_ENUM:
    case TYPE_CODE_BOOL:
    case TYPE_CODE_INT:
    case TYPE_CODE_CHAR:
    case TYPE_CODE_RANGE:
      if (nosign)
	return extract_unsigned_integer (valaddr, len);
      else
	return extract_signed_integer (valaddr, len);

    case TYPE_CODE_FLT:
      return extract_typed_floating (valaddr, type);

    case TYPE_CODE_PTR:
    case TYPE_CODE_REF:
      /* Assume a CORE_ADDR can fit in a LONGEST (for now).  Not sure
         whether we want this to be true eventually.  */
      return extract_typed_address (valaddr, type);

    case TYPE_CODE_MEMBER:
      error ("not implemented: member types in unpack_long");

    default:
      error ("Value can't be converted to integer.");
    }
  return 0;			/* Placate lint.  */
}

/* Return a double value from the specified type and address.
   INVP points to an int which is set to 0 for valid value,
   1 for invalid value (bad float format).  In either case,
   the returned double is OK to use.  Argument is in target
   format, result is in host format.  */

DOUBLEST
unpack_double (struct type *type, const char *valaddr, int *invp)
{
  enum type_code code;
  int len;
  int nosign;

  *invp = 0;			/* Assume valid.   */
  CHECK_TYPEDEF (type);
  code = TYPE_CODE (type);
  len = TYPE_LENGTH (type);
  nosign = TYPE_UNSIGNED (type);
  if (code == TYPE_CODE_FLT)
    {
      /* NOTE: cagney/2002-02-19: There was a test here to see if the
	 floating-point value was valid (using the macro
	 INVALID_FLOAT).  That test/macro have been removed.

	 It turns out that only the VAX defined this macro and then
	 only in a non-portable way.  Fixing the portability problem
	 wouldn't help since the VAX floating-point code is also badly
	 bit-rotten.  The target needs to add definitions for the
	 methods TARGET_FLOAT_FORMAT and TARGET_DOUBLE_FORMAT - these
	 exactly describe the target floating-point format.  The
	 problem here is that the corresponding floatformat_vax_f and
	 floatformat_vax_d values these methods should be set to are
	 also not defined either.  Oops!

         Hopefully someone will add both the missing floatformat
         definitions and floatformat_is_invalid() function.  */
      return extract_typed_floating (valaddr, type);
    }
  else if (nosign)
    {
      /* Unsigned -- be sure we compensate for signed LONGEST.  */
      return (ULONGEST) unpack_long (type, valaddr);
    }
  else
    {
      /* Signed -- we are OK with unpack_long.  */
      return unpack_long (type, valaddr);
    }
}

/* Unpack raw data (copied from debugee, target byte order) at VALADDR
   as a CORE_ADDR, assuming the raw data is described by type TYPE.
   We don't assume any alignment for the raw data.  Return value is in
   host byte order.

   If you want functions and arrays to be coerced to pointers, and
   references to be dereferenced, call value_as_address() instead.

   C++: It is assumed that the front-end has taken care of
   all matters concerning pointers to members.  A pointer
   to member which reaches here is considered to be equivalent
   to an INT (or some size).  After all, it is only an offset.  */

CORE_ADDR
unpack_pointer (struct type *type, const char *valaddr)
{
  /* Assume a CORE_ADDR can fit in a LONGEST (for now).  Not sure
     whether we want this to be true eventually.  */
  return unpack_long (type, valaddr);
}


/* Get the value of the FIELDN'th field (which must be static) of
   TYPE.  Return NULL if the field doesn't exist or has been
   optimized out. */

struct value *
value_static_field (struct type *type, int fieldno)
{
  struct value *retval;

  if (TYPE_FIELD_STATIC_HAS_ADDR (type, fieldno))
    {
      retval = value_at (TYPE_FIELD_TYPE (type, fieldno),
			 TYPE_FIELD_STATIC_PHYSADDR (type, fieldno),
			 NULL);
    }
  else
    {
      char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno);
      struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0, NULL);
      if (sym == NULL)
	{
	  /* With some compilers, e.g. HP aCC, static data members are reported
	     as non-debuggable symbols */
	  struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL);
	  if (!msym)
	    return NULL;
	  else
	    {
	      retval = value_at (TYPE_FIELD_TYPE (type, fieldno),
				 SYMBOL_VALUE_ADDRESS (msym),
				 SYMBOL_BFD_SECTION (msym));
	    }
	}
      else
	{
	  /* SYM should never have a SYMBOL_CLASS which will require
	     read_var_value to use the FRAME parameter.  */
	  if (symbol_read_needs_frame (sym))
	    warning ("static field's value depends on the current "
		     "frame - bad debug info?");
	  retval = read_var_value (sym, NULL);
 	}
      if (retval && VALUE_LVAL (retval) == lval_memory)
	SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno),
			    VALUE_ADDRESS (retval));
    }
  return retval;
}

/* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.  
   You have to be careful here, since the size of the data area for the value 
   is set by the length of the enclosing type.  So if NEW_ENCL_TYPE is bigger 
   than the old enclosing type, you have to allocate more space for the data.  
   The return value is a pointer to the new version of this value structure. */

struct value *
value_change_enclosing_type (struct value *val, struct type *new_encl_type)
{
  if (TYPE_LENGTH (new_encl_type) <= TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val))) 
    {
      VALUE_ENCLOSING_TYPE (val) = new_encl_type;
      return val;
    }
  else
    {
      struct value *new_val;
      struct value *prev;
      
      new_val = (struct value *) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type));

      VALUE_ENCLOSING_TYPE (new_val) = new_encl_type;
 
      /* We have to make sure this ends up in the same place in the value
	 chain as the original copy, so it's clean-up behavior is the same. 
	 If the value has been released, this is a waste of time, but there
	 is no way to tell that in advance, so... */
      
      if (val != all_values) 
	{
	  for (prev = all_values; prev != NULL; prev = prev->next)
	    {
	      if (prev->next == val) 
		{
		  prev->next = new_val;
		  break;
		}
	    }
	}
      
      return new_val;
    }
}

/* Given a value ARG1 (offset by OFFSET bytes)
   of a struct or union type ARG_TYPE,
   extract and return the value of one of its (non-static) fields.
   FIELDNO says which field. */

struct value *
value_primitive_field (struct value *arg1, int offset,
		       register int fieldno, register struct type *arg_type)
{
  struct value *v;
  register struct type *type;

  CHECK_TYPEDEF (arg_type);
  type = TYPE_FIELD_TYPE (arg_type, fieldno);

  /* Handle packed fields */

  if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
    {
      v = value_from_longest (type,
			      unpack_field_as_long (arg_type,
						    VALUE_CONTENTS (arg1)
						    + offset,
						    fieldno));
      VALUE_BITPOS (v) = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8;
      VALUE_BITSIZE (v) = TYPE_FIELD_BITSIZE (arg_type, fieldno);
      VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset
	+ TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
    }
  else if (fieldno < TYPE_N_BASECLASSES (arg_type))
    {
      /* This field is actually a base subobject, so preserve the
         entire object's contents for later references to virtual
         bases, etc.  */
      v = allocate_value (VALUE_ENCLOSING_TYPE (arg1));
      VALUE_TYPE (v) = type;
      if (VALUE_LAZY (arg1))
	VALUE_LAZY (v) = 1;
      else
	memcpy (VALUE_CONTENTS_ALL_RAW (v), VALUE_CONTENTS_ALL_RAW (arg1),
		TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg1)));
      VALUE_OFFSET (v) = VALUE_OFFSET (arg1);
      VALUE_EMBEDDED_OFFSET (v)
	= offset +
	VALUE_EMBEDDED_OFFSET (arg1) +
	TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
    }
  else
    {
      /* Plain old data member */
      offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
      v = allocate_value (type);
      if (VALUE_LAZY (arg1))
	VALUE_LAZY (v) = 1;
      else
	memcpy (VALUE_CONTENTS_RAW (v),
		VALUE_CONTENTS_RAW (arg1) + offset,
		TYPE_LENGTH (type));
      VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset
			 + VALUE_EMBEDDED_OFFSET (arg1);
    }
  VALUE_LVAL (v) = VALUE_LVAL (arg1);
  if (VALUE_LVAL (arg1) == lval_internalvar)
    VALUE_LVAL (v) = lval_internalvar_component;
  VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1);
  VALUE_REGNO (v) = VALUE_REGNO (arg1);
/*  VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset
   + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; */
  return v;
}

/* Given a value ARG1 of a struct or union type,
   extract and return the value of one of its (non-static) fields.
   FIELDNO says which field. */

struct value *
value_field (struct value *arg1, register int fieldno)
{
  return value_primitive_field (arg1, 0, fieldno, VALUE_TYPE (arg1));
}

/* Return a non-virtual function as a value.
   F is the list of member functions which contains the desired method.
   J is an index into F which provides the desired method.

   We only use the symbol for its address, so be happy with either a
   full symbol or a minimal symbol.
 */

struct value *
value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type,
		int offset)
{
  struct value *v;
  register struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
  char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
  struct symbol *sym;
  struct minimal_symbol *msym;

  sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0, NULL);
  if (sym != NULL)
    {
      msym = NULL;
    }
  else
    {
      gdb_assert (sym == NULL);
      msym = lookup_minimal_symbol (physname, NULL, NULL);
      if (msym == NULL)
	return NULL;
    }

  v = allocate_value (ftype);
  if (sym)
    {
      VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
    }
  else
    {
      VALUE_ADDRESS (v) = SYMBOL_VALUE_ADDRESS (msym);
    }

  if (arg1p)
    {
      if (type != VALUE_TYPE (*arg1p))
	*arg1p = value_ind (value_cast (lookup_pointer_type (type),
					value_addr (*arg1p)));

      /* Move the `this' pointer according to the offset.
         VALUE_OFFSET (*arg1p) += offset;
       */
    }

  return v;
}


/* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at
   VALADDR.

   Extracting bits depends on endianness of the machine.  Compute the
   number of least significant bits to discard.  For big endian machines,
   we compute the total number of bits in the anonymous object, subtract
   off the bit count from the MSB of the object to the MSB of the
   bitfield, then the size of the bitfield, which leaves the LSB discard
   count.  For little endian machines, the discard count is simply the
   number of bits from the LSB of the anonymous object to the LSB of the
   bitfield.

   If the field is signed, we also do sign extension. */

LONGEST
unpack_field_as_long (struct type *type, const char *valaddr, int fieldno)
{
  ULONGEST val;
  ULONGEST valmask;
  int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
  int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
  int lsbcount;
  struct type *field_type;

  val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val));
  field_type = TYPE_FIELD_TYPE (type, fieldno);
  CHECK_TYPEDEF (field_type);

  /* Extract bits.  See comment above. */

  if (BITS_BIG_ENDIAN)
    lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize);
  else
    lsbcount = (bitpos % 8);
  val >>= lsbcount;

  /* If the field does not entirely fill a LONGEST, then zero the sign bits.
     If the field is signed, and is negative, then sign extend. */

  if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val)))
    {
      valmask = (((ULONGEST) 1) << bitsize) - 1;
      val &= valmask;
      if (!TYPE_UNSIGNED (field_type))
	{
	  if (val & (valmask ^ (valmask >> 1)))
	    {
	      val |= ~valmask;
	    }
	}
    }
  return (val);
}

/* Modify the value of a bitfield.  ADDR points to a block of memory in
   target byte order; the bitfield starts in the byte pointed to.  FIELDVAL
   is the desired value of the field, in host byte order.  BITPOS and BITSIZE
   indicate which bits (in target bit order) comprise the bitfield.  */

void
modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize)
{
  LONGEST oword;

  /* If a negative fieldval fits in the field in question, chop
     off the sign extension bits.  */
  if (bitsize < (8 * (int) sizeof (fieldval))
      && (~fieldval & ~((1 << (bitsize - 1)) - 1)) == 0)
    fieldval = fieldval & ((1 << bitsize) - 1);

  /* Warn if value is too big to fit in the field in question.  */
  if (bitsize < (8 * (int) sizeof (fieldval))
      && 0 != (fieldval & ~((1 << bitsize) - 1)))
    {
      /* FIXME: would like to include fieldval in the message, but
         we don't have a sprintf_longest.  */
      warning ("Value does not fit in %d bits.", bitsize);

      /* Truncate it, otherwise adjoining fields may be corrupted.  */
      fieldval = fieldval & ((1 << bitsize) - 1);
    }

  oword = extract_signed_integer (addr, sizeof oword);

  /* Shifting for bit field depends on endianness of the target machine.  */
  if (BITS_BIG_ENDIAN)
    bitpos = sizeof (oword) * 8 - bitpos - bitsize;

  /* Mask out old value, while avoiding shifts >= size of oword */
  if (bitsize < 8 * (int) sizeof (oword))
    oword &= ~(((((ULONGEST) 1) << bitsize) - 1) << bitpos);
  else
    oword &= ~((~(ULONGEST) 0) << bitpos);
  oword |= fieldval << bitpos;

  store_signed_integer (addr, sizeof oword, oword);
}

/* Convert C numbers into newly allocated values */

struct value *
value_from_longest (struct type *type, register LONGEST num)
{
  struct value *val = allocate_value (type);
  register enum type_code code;
  register int len;
retry:
  code = TYPE_CODE (type);
  len = TYPE_LENGTH (type);

  switch (code)
    {
    case TYPE_CODE_TYPEDEF:
      type = check_typedef (type);
      goto retry;
    case TYPE_CODE_INT:
    case TYPE_CODE_CHAR:
    case TYPE_CODE_ENUM:
    case TYPE_CODE_BOOL:
    case TYPE_CODE_RANGE:
      store_signed_integer (VALUE_CONTENTS_RAW (val), len, num);
      break;

    case TYPE_CODE_REF:
    case TYPE_CODE_PTR:
      store_typed_address (VALUE_CONTENTS_RAW (val), type, (CORE_ADDR) num);
      break;

    default:
      error ("Unexpected type (%d) encountered for integer constant.", code);
    }
  return val;
}


/* Create a value representing a pointer of type TYPE to the address
   ADDR.  */
struct value *
value_from_pointer (struct type *type, CORE_ADDR addr)
{
  struct value *val = allocate_value (type);
  store_typed_address (VALUE_CONTENTS_RAW (val), type, addr);
  return val;
}


/* Create a value for a string constant to be stored locally
   (not in the inferior's memory space, but in GDB memory).
   This is analogous to value_from_longest, which also does not
   use inferior memory.  String shall NOT contain embedded nulls.  */

struct value *
value_from_string (char *ptr)
{
  struct value *val;
  int len = strlen (ptr);
  int lowbound = current_language->string_lower_bound;
  struct type *rangetype =
  create_range_type ((struct type *) NULL,
		     builtin_type_int,
		     lowbound, len + lowbound - 1);
  struct type *stringtype =
  create_array_type ((struct type *) NULL,
		     *current_language->string_char_type,
		     rangetype);

  val = allocate_value (stringtype);
  memcpy (VALUE_CONTENTS_RAW (val), ptr, len);
  return val;
}

struct value *
value_from_double (struct type *type, DOUBLEST num)
{
  struct value *val = allocate_value (type);
  struct type *base_type = check_typedef (type);
  register enum type_code code = TYPE_CODE (base_type);
  register int len = TYPE_LENGTH (base_type);

  if (code == TYPE_CODE_FLT)
    {
      store_typed_floating (VALUE_CONTENTS_RAW (val), base_type, num);
    }
  else
    error ("Unexpected type encountered for floating constant.");

  return val;
}

/* Deal with the value that is "about to be returned".  */

/* Return the value that a function returning now
   would be returning to its caller, assuming its type is VALTYPE.
   RETBUF is where we look for what ought to be the contents
   of the registers (in raw form).  This is because it is often
   desirable to restore old values to those registers
   after saving the contents of interest, and then call
   this function using the saved values.
   struct_return is non-zero when the function in question is
   using the structure return conventions on the machine in question;
   0 when it is using the value returning conventions (this often
   means returning pointer to where structure is vs. returning value). */

/* ARGSUSED */
struct value *
value_being_returned (struct type *valtype, struct regcache *retbuf,
		      int struct_return)
{
  struct value *val;
  CORE_ADDR addr;

  /* If this is not defined, just use EXTRACT_RETURN_VALUE instead.  */
  if (EXTRACT_STRUCT_VALUE_ADDRESS_P ())
    if (struct_return)
      {
	addr = EXTRACT_STRUCT_VALUE_ADDRESS (retbuf);
	if (!addr)
	  error ("Function return value unknown.");
	return value_at (valtype, addr, NULL);
      }

  /* If this is not defined, just use EXTRACT_RETURN_VALUE instead.  */
  if (DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS_P ())
    if (struct_return)
      {
	char *buf = deprecated_grub_regcache_for_registers (retbuf);
	addr = DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS (buf);
	if (!addr)
	  error ("Function return value unknown.");
	return value_at (valtype, addr, NULL);
      }

  val = allocate_value (valtype);
  CHECK_TYPEDEF (valtype);
  /* If the function returns void, don't bother fetching the return value.  */
  if (TYPE_CODE (valtype) != TYPE_CODE_VOID)
    EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));

  return val;
}

/* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of
   EXTRACT_RETURN_VALUE?  GCC_P is true if compiled with gcc
   and TYPE is the type (which is known to be struct, union or array).

   On most machines, the struct convention is used unless we are
   using gcc and the type is of a special size.  */
/* As of about 31 Mar 93, GCC was changed to be compatible with the
   native compiler.  GCC 2.3.3 was the last release that did it the
   old way.  Since gcc2_compiled was not changed, we have no
   way to correctly win in all cases, so we just do the right thing
   for gcc1 and for gcc2 after this change.  Thus it loses for gcc
   2.0-2.3.3.  This is somewhat unfortunate, but changing gcc2_compiled
   would cause more chaos than dealing with some struct returns being
   handled wrong.  */

int
generic_use_struct_convention (int gcc_p, struct type *value_type)
{
  return !((gcc_p == 1)
	   && (TYPE_LENGTH (value_type) == 1
	       || TYPE_LENGTH (value_type) == 2
	       || TYPE_LENGTH (value_type) == 4
	       || TYPE_LENGTH (value_type) == 8));
}

/* Return true if the function specified is using the structure returning
   convention on this machine to return arguments, or 0 if it is using
   the value returning convention.  FUNCTION is the value representing
   the function, FUNCADDR is the address of the function, and VALUE_TYPE
   is the type returned by the function.  GCC_P is nonzero if compiled
   with GCC.  */

/* ARGSUSED */
int
using_struct_return (struct value *function, CORE_ADDR funcaddr,
		     struct type *value_type, int gcc_p)
{
  register enum type_code code = TYPE_CODE (value_type);

  if (code == TYPE_CODE_ERROR)
    error ("Function return type unknown.");

  if (code == TYPE_CODE_STRUCT
      || code == TYPE_CODE_UNION
      || code == TYPE_CODE_ARRAY
      || RETURN_VALUE_ON_STACK (value_type))
    return USE_STRUCT_CONVENTION (gcc_p, value_type);

  return 0;
}

/* Store VAL so it will be returned if a function returns now.
   Does not verify that VAL's type matches what the current
   function wants to return.  */

void
set_return_value (struct value *val)
{
  struct type *type = check_typedef (VALUE_TYPE (val));
  register enum type_code code = TYPE_CODE (type);

  if (code == TYPE_CODE_ERROR)
    error ("Function return type unknown.");

  if (code == TYPE_CODE_STRUCT
      || code == TYPE_CODE_UNION)	/* FIXME, implement struct return.  */
    error ("GDB does not support specifying a struct or union return value.");

  STORE_RETURN_VALUE (type, current_regcache, VALUE_CONTENTS (val));
}

void
_initialize_values (void)
{
  add_cmd ("convenience", no_class, show_convenience,
	   "Debugger convenience (\"$foo\") variables.\n\
These variables are created when you assign them values;\n\
thus, \"print $foo=1\" gives \"$foo\" the value 1.  Values may be any type.\n\n\
A few convenience variables are given values automatically:\n\
\"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
\"$__\" holds the contents of the last address examined with \"x\".",
	   &showlist);

  add_cmd ("values", no_class, show_values,
	   "Elements of value history around item number IDX (or last ten).",
	   &showlist);
}