gdb/typeprint.c

   1 /* Language independent support for printing types for GDB, the GNU debugger.
   2    Copyright 1986, 1988, 1989, 1991 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include "defs.h"
  21 #include "obstack.h"
  22 #include "bfd.h"                /* Binary File Description */
  23 #include "symtab.h"
  24 #include "gdbtypes.h"
  25 #include "expression.h"
  26 #include "value.h"
  27 #include "gdbcore.h"
  28 #include "command.h"
  29 #include "gdbcmd.h"
  30 #include "target.h"
  31 #include "language.h"
  32 #include "demangle.h"
  33
  34 #include <string.h>
  35 #include <errno.h>
  36
  37 static void
  38 ptype_command PARAMS ((char *, int));
  39
  40 static struct type *
  41 ptype_eval PARAMS ((struct expression *));
  42
  43 static void
  44 whatis_command PARAMS ((char *, int));
  45
  46 static void
  47 whatis_exp PARAMS ((char *, int));
  48
  49 /* Print a description of a type TYPE in the form of a declaration of a
  50    variable named VARSTRING.  (VARSTRING is demangled if necessary.)
  51    Output goes to STREAM (via stdio).
  52    If SHOW is positive, we show the contents of the outermost level
  53    of structure even if there is a type name that could be used instead.
  54    If SHOW is negative, we never show the details of elements' types.  */
  55
  56 void
  57 type_print (type, varstring, stream, show)
  58      struct type *type;
  59      char *varstring;
  60      FILE *stream;
  61      int show;
  62 {
  63   LA_PRINT_TYPE (type, varstring, stream, show, 0);
  64 }
  65
  66 /* Print type of EXP, or last thing in value history if EXP == NULL.
  67    show is passed to type_print.  */
  68
  69 static void
  70 whatis_exp (exp, show)
  71      char *exp;
  72      int show;
  73 {
  74   struct expression *expr;
  75   register value val;
  76   register struct cleanup *old_chain;
  77
  78   if (exp)
  79     {
  80       expr = parse_expression (exp);
  81       old_chain = make_cleanup (free_current_contents, &expr);
  82       val = evaluate_type (expr);
  83     }
  84   else
  85     val = access_value_history (0);
  86
  87   printf_filtered ("type = ");
  88   type_print (VALUE_TYPE (val), "", stdout, show);
  89   printf_filtered ("\n");
  90
  91   if (exp)
  92     do_cleanups (old_chain);
  93 }
  94
  95 /* ARGSUSED */
  96 static void
  97 whatis_command (exp, from_tty)
  98      char *exp;
  99      int from_tty;
 100 {
 101   /* Most of the time users do not want to see all the fields
 102      in a structure.  If they do they can use the "ptype" command.
 103      Hence the "-1" below.  */
 104   whatis_exp (exp, -1);
 105 }
 106
 107 /* Simple subroutine for ptype_command.  */
 108
 109 static struct type *
 110 ptype_eval (exp)
 111      struct expression *exp;
 112 {
 113   if (exp->elts[0].opcode == OP_TYPE)
 114     {
 115       return (exp->elts[1].type);
 116     }
 117   else
 118     {
 119       return (NULL);
 120     }
 121 }
 122
 123 /* TYPENAME is either the name of a type, or an expression.  */
 124
 125 /* ARGSUSED */
 126 static void
 127 ptype_command (typename, from_tty)
 128      char *typename;
 129      int from_tty;
 130 {
 131   register struct type *type;
 132   struct expression *expr;
 133   register struct cleanup *old_chain;
 134
 135   if (typename == NULL)
 136     {
 137       /* Print type of last thing in value history. */
 138       whatis_exp (typename, 1);
 139     }
 140   else
 141     {
 142       expr = parse_expression (typename);
 143       old_chain = make_cleanup (free_current_contents, &expr);
 144       type = ptype_eval (expr);
 145       if (type != NULL)
 146         {
 147           /* User did "ptype <typename>" */
 148           printf_filtered ("type = ");
 149           type_print (type, "", stdout, 1);
 150           printf_filtered ("\n");
 151           do_cleanups (old_chain);
 152         }
 153       else
 154         {
 155           /* User did "ptype <symbolname>" */
 156           do_cleanups (old_chain);
 157           whatis_exp (typename, 1);
 158         }
 159     }
 160 }
 161
 162 /* Print integral scalar data VAL, of type TYPE, onto stdio stream STREAM.
 163    Used to print data from type structures in a specified type.  For example,
 164    array bounds may be characters or booleans in some languages, and this
 165    allows the ranges to be printed in their "natural" form rather than as
 166    decimal integer values.
 167
 168    FIXME:  This is here simply because only the type printing routines
 169    currently use it, and it wasn't clear if it really belonged somewhere
 170    else (like printcmd.c).  There are a lot of other gdb routines that do
 171    something similar, but they are generally concerned with printing values
 172    that come from the inferior in target byte order and target size. */
 173
 174 void
 175 print_type_scalar (type, val, stream)
 176      struct type *type;
 177      LONGEST val;
 178      FILE *stream;
 179 {
 180   unsigned int i;
 181   unsigned len;
 182
 183   switch (TYPE_CODE (type))
 184     {
 185
 186     case TYPE_CODE_ENUM:
 187       len = TYPE_NFIELDS (type);
 188       for (i = 0; i < len; i++)
 189         {
 190           if (TYPE_FIELD_BITPOS (type, i) == val)
 191             {
 192               break;
 193             }
 194         }
 195       if (i < len)
 196         {
 197           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 198         }
 199       else
 200         {
 201 #ifdef LONG_LONG
 202           fprintf_filtered (stream, "%lld", val);
 203 #else
 204           fprintf_filtered (stream, "%ld", val);
 205 #endif
 206         }
 207       break;
 208
 209     case TYPE_CODE_INT:
 210 #ifdef LONG_LONG
 211       fprintf_filtered (stream, TYPE_UNSIGNED (type) ? "%llu" : "%lld", val);
 212 #else
 213       fprintf_filtered (stream, TYPE_UNSIGNED (type) ? "%u" : "%d", val);
 214 #endif
 215       break;
 216
 217     case TYPE_CODE_CHAR:
 218       LA_PRINT_CHAR ((unsigned char) val, stream);
 219       break;
 220
 221     case TYPE_CODE_BOOL:
 222       fprintf_filtered (stream, val ? "TRUE" : "FALSE");
 223       break;
 224
 225     case TYPE_CODE_UNDEF:
 226     case TYPE_CODE_PTR:
 227     case TYPE_CODE_ARRAY:
 228     case TYPE_CODE_STRUCT:
 229     case TYPE_CODE_UNION:
 230     case TYPE_CODE_FUNC:
 231     case TYPE_CODE_FLT:
 232     case TYPE_CODE_VOID:
 233     case TYPE_CODE_SET:
 234     case TYPE_CODE_RANGE:
 235     case TYPE_CODE_PASCAL_ARRAY:
 236     case TYPE_CODE_ERROR:
 237     case TYPE_CODE_MEMBER:
 238     case TYPE_CODE_METHOD:
 239     case TYPE_CODE_REF:
 240       error ("internal error: unhandled type in print_type_scalar");
 241       break;
 242
 243     default:
 244       error ("Invalid type code in symbol table.");
 245     }
 246   fflush (stream);
 247 }
 248
 249 #if MAINTENANCE_CMDS
 250
 251 /* Dump details of a type specified either directly or indirectly.
 252    Uses the same sort of type lookup mechanism as ptype_command()
 253    and whatis_command(). */
 254
 255 void
 256 maintenance_print_type (typename, from_tty)
 257      char *typename;
 258      int from_tty;
 259 {
 260   register value val;
 261   register struct type *type;
 262   register struct cleanup *old_chain;
 263   struct expression *expr;
 264
 265   if (typename != NULL)
 266   {
 267     expr = parse_expression (typename);
 268     old_chain = make_cleanup (free_current_contents, &expr);
 269     if (expr -> elts[0].opcode == OP_TYPE)
 270       {
 271         /* The user expression names a type directly, just use that type. */
 272         type = expr -> elts[1].type;
 273       }
 274     else
 275       {
 276         /* The user expression may name a type indirectly by naming an
 277            object of that type.  Find that indirectly named type. */
 278         val = evaluate_type (expr);
 279         type = VALUE_TYPE (val);
 280       }
 281     if (type != NULL)
 282       {
 283         recursive_dump_type (type, 0);
 284       }
 285     do_cleanups (old_chain);
 286   }
 287 }
 288
 289 #endif  /* MAINTENANCE_CMDS */
 290
 291 \f
 292 void
 293 _initialize_typeprint ()
 294 {
 295
 296   add_com ("ptype", class_vars, ptype_command,
 297            "Print definition of type TYPE.\n\
 298 Argument may be a type name defined by typedef, or \"struct STRUCTNAME\"\n\
 299 or \"union UNIONNAME\" or \"enum ENUMNAME\".\n\
 300 The selected stack frame's lexical context is used to look up the name.");
 301
 302   add_com ("whatis", class_vars, whatis_command,
 303            "Print data type of expression EXP.");
 304
 305 }