gdb/typeprint.c

   1 /* Language independent support for printing types for GDB, the GNU debugger.
   2    Copyright 1986, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1998, 1999,
   3    2000 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 2 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, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #include "defs.h"
  23 #include "obstack.h"
  24 #include "bfd.h"                /* Binary File Description */
  25 #include "symtab.h"
  26 #include "gdbtypes.h"
  27 #include "expression.h"
  28 #include "value.h"
  29 #include "gdbcore.h"
  30 #include "command.h"
  31 #include "gdbcmd.h"
  32 #include "target.h"
  33 #include "language.h"
  34
  35 #include "gdb_string.h"
  36 #include <errno.h>
  37
  38 /* For real-type printing in whatis_exp() */
  39 extern int objectprint;         /* Controls looking up an object's derived type
  40                                    using what we find in its vtables.  */
  41
  42 extern void _initialize_typeprint (void);
  43
  44 static void ptype_command (char *, int);
  45
  46 static struct type *ptype_eval (struct expression *);
  47
  48 static void whatis_command (char *, int);
  49
  50 static void whatis_exp (char *, int);
  51
  52 /* Print a description of a type in the format of a
  53    typedef for the current language.
  54    NEW is the new name for a type TYPE. */
  55
  56 void
  57 typedef_print (struct type *type, struct symbol *new, struct ui_file *stream)
  58 {
  59   CHECK_TYPEDEF (type);
  60   switch (current_language->la_language)
  61     {
  62 #ifdef _LANG_c
  63     case language_c:
  64     case language_cplus:
  65       fprintf_filtered (stream, "typedef ");
  66       type_print (type, "", stream, 0);
  67       if (TYPE_NAME ((SYMBOL_TYPE (new))) == 0
  68           || !STREQ (TYPE_NAME ((SYMBOL_TYPE (new))), SYMBOL_NAME (new)))
  69         fprintf_filtered (stream, " %s", SYMBOL_SOURCE_NAME (new));
  70       break;
  71 #endif
  72 #ifdef _LANG_m2
  73     case language_m2:
  74       fprintf_filtered (stream, "TYPE ");
  75       if (!TYPE_NAME (SYMBOL_TYPE (new)) ||
  76           !STREQ (TYPE_NAME (SYMBOL_TYPE (new)), SYMBOL_NAME (new)))
  77         fprintf_filtered (stream, "%s = ", SYMBOL_SOURCE_NAME (new));
  78       else
  79         fprintf_filtered (stream, "<builtin> = ");
  80       type_print (type, "", stream, 0);
  81       break;
  82 #endif
  83 #ifdef _LANG_pascal
  84     case language_pascal:
  85       fprintf_filtered (stream, "type ");
  86       fprintf_filtered (stream, "%s = ", SYMBOL_SOURCE_NAME (new));
  87       type_print (type, "", stream, 0);
  88       break;
  89 #endif
  90 #ifdef _LANG_chill
  91     case language_chill:
  92       fprintf_filtered (stream, "SYNMODE ");
  93       if (!TYPE_NAME (SYMBOL_TYPE (new)) ||
  94           !STREQ (TYPE_NAME (SYMBOL_TYPE (new)), SYMBOL_NAME (new)))
  95         fprintf_filtered (stream, "%s = ", SYMBOL_SOURCE_NAME (new));
  96       else
  97         fprintf_filtered (stream, "<builtin> = ");
  98       type_print (type, "", stream, 0);
  99       break;
 100 #endif
 101     default:
 102       error ("Language not supported.");
 103     }
 104   fprintf_filtered (stream, ";\n");
 105 }
 106
 107 /* Print a description of a type TYPE in the form of a declaration of a
 108    variable named VARSTRING.  (VARSTRING is demangled if necessary.)
 109    Output goes to STREAM (via stdio).
 110    If SHOW is positive, we show the contents of the outermost level
 111    of structure even if there is a type name that could be used instead.
 112    If SHOW is negative, we never show the details of elements' types.  */
 113
 114 void
 115 type_print (struct type *type, char *varstring, struct ui_file *stream,
 116             int show)
 117 {
 118   LA_PRINT_TYPE (type, varstring, stream, show, 0);
 119 }
 120
 121 /* Print type of EXP, or last thing in value history if EXP == NULL.
 122    show is passed to type_print.  */
 123
 124 static void
 125 whatis_exp (char *exp, int show)
 126 {
 127   struct expression *expr;
 128   register value_ptr val;
 129   register struct cleanup *old_chain = NULL;
 130   struct type *real_type = NULL;
 131   struct type *type;
 132   int full = 0;
 133   int top = -1;
 134   int using_enc = 0;
 135
 136   if (exp)
 137     {
 138       expr = parse_expression (exp);
 139       old_chain = make_cleanup (free_current_contents, &expr);
 140       val = evaluate_type (expr);
 141     }
 142   else
 143     val = access_value_history (0);
 144
 145   type = VALUE_TYPE (val);
 146
 147   if (objectprint)
 148     {
 149       if (((TYPE_CODE (type) == TYPE_CODE_PTR) ||
 150            (TYPE_CODE (type) == TYPE_CODE_REF))
 151           &&
 152           (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS))
 153         {
 154           real_type = value_rtti_target_type (val, &full, &top, &using_enc);
 155           if (real_type)
 156             {
 157               if (TYPE_CODE (type) == TYPE_CODE_PTR)
 158                 real_type = lookup_pointer_type (real_type);
 159               else
 160                 real_type = lookup_reference_type (real_type);
 161             }
 162         }
 163       else if (TYPE_CODE (type) == TYPE_CODE_CLASS)
 164   real_type = value_rtti_type (val, &full, &top, &using_enc);
 165     }
 166
 167   printf_filtered ("type = ");
 168
 169   if (real_type)
 170     {
 171       printf_filtered ("/* real type = ");
 172       type_print (real_type, "", gdb_stdout, -1);
 173       if (! full)
 174         printf_filtered (" (incomplete object)");
 175       printf_filtered (" */\n");
 176     }
 177
 178   type_print (type, "", gdb_stdout, show);
 179   printf_filtered ("\n");
 180
 181   if (exp)
 182     do_cleanups (old_chain);
 183 }
 184
 185 /* ARGSUSED */
 186 static void
 187 whatis_command (char *exp, int from_tty)
 188 {
 189   /* Most of the time users do not want to see all the fields
 190      in a structure.  If they do they can use the "ptype" command.
 191      Hence the "-1" below.  */
 192   whatis_exp (exp, -1);
 193 }
 194
 195 /* Simple subroutine for ptype_command.  */
 196
 197 static struct type *
 198 ptype_eval (struct expression *exp)
 199 {
 200   if (exp->elts[0].opcode == OP_TYPE)
 201     {
 202       return (exp->elts[1].type);
 203     }
 204   else
 205     {
 206       return (NULL);
 207     }
 208 }
 209
 210 /* TYPENAME is either the name of a type, or an expression.  */
 211
 212 /* ARGSUSED */
 213 static void
 214 ptype_command (char *typename, int from_tty)
 215 {
 216   register struct type *type;
 217   struct expression *expr;
 218   register struct cleanup *old_chain;
 219
 220   if (typename == NULL)
 221     {
 222       /* Print type of last thing in value history. */
 223       whatis_exp (typename, 1);
 224     }
 225   else
 226     {
 227       expr = parse_expression (typename);
 228       old_chain = make_cleanup (free_current_contents, &expr);
 229       type = ptype_eval (expr);
 230       if (type != NULL)
 231         {
 232           /* User did "ptype <typename>" */
 233           printf_filtered ("type = ");
 234           type_print (type, "", gdb_stdout, 1);
 235           printf_filtered ("\n");
 236           do_cleanups (old_chain);
 237         }
 238       else
 239         {
 240           /* User did "ptype <symbolname>" */
 241           do_cleanups (old_chain);
 242           whatis_exp (typename, 1);
 243         }
 244     }
 245 }
 246
 247 /* Print integral scalar data VAL, of type TYPE, onto stdio stream STREAM.
 248    Used to print data from type structures in a specified type.  For example,
 249    array bounds may be characters or booleans in some languages, and this
 250    allows the ranges to be printed in their "natural" form rather than as
 251    decimal integer values.
 252
 253    FIXME:  This is here simply because only the type printing routines
 254    currently use it, and it wasn't clear if it really belonged somewhere
 255    else (like printcmd.c).  There are a lot of other gdb routines that do
 256    something similar, but they are generally concerned with printing values
 257    that come from the inferior in target byte order and target size. */
 258
 259 void
 260 print_type_scalar (struct type *type, LONGEST val, struct ui_file *stream)
 261 {
 262   unsigned int i;
 263   unsigned len;
 264
 265   CHECK_TYPEDEF (type);
 266
 267   switch (TYPE_CODE (type))
 268     {
 269
 270     case TYPE_CODE_ENUM:
 271       len = TYPE_NFIELDS (type);
 272       for (i = 0; i < len; i++)
 273         {
 274           if (TYPE_FIELD_BITPOS (type, i) == val)
 275             {
 276               break;
 277             }
 278         }
 279       if (i < len)
 280         {
 281           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 282         }
 283       else
 284         {
 285           print_longest (stream, 'd', 0, val);
 286         }
 287       break;
 288
 289     case TYPE_CODE_INT:
 290       print_longest (stream, TYPE_UNSIGNED (type) ? 'u' : 'd', 0, val);
 291       break;
 292
 293     case TYPE_CODE_CHAR:
 294       LA_PRINT_CHAR ((unsigned char) val, stream);
 295       break;
 296
 297     case TYPE_CODE_BOOL:
 298       fprintf_filtered (stream, val ? "TRUE" : "FALSE");
 299       break;
 300
 301     case TYPE_CODE_RANGE:
 302       print_type_scalar (TYPE_TARGET_TYPE (type), val, stream);
 303       return;
 304
 305     case TYPE_CODE_UNDEF:
 306     case TYPE_CODE_PTR:
 307     case TYPE_CODE_ARRAY:
 308     case TYPE_CODE_STRUCT:
 309     case TYPE_CODE_UNION:
 310     case TYPE_CODE_FUNC:
 311     case TYPE_CODE_FLT:
 312     case TYPE_CODE_VOID:
 313     case TYPE_CODE_SET:
 314     case TYPE_CODE_STRING:
 315     case TYPE_CODE_ERROR:
 316     case TYPE_CODE_MEMBER:
 317     case TYPE_CODE_METHOD:
 318     case TYPE_CODE_REF:
 319       error ("internal error: unhandled type in print_type_scalar");
 320       break;
 321
 322     default:
 323       error ("Invalid type code in symbol table.");
 324     }
 325   gdb_flush (stream);
 326 }
 327
 328 /* Dump details of a type specified either directly or indirectly.
 329    Uses the same sort of type lookup mechanism as ptype_command()
 330    and whatis_command(). */
 331
 332 void
 333 maintenance_print_type (char *typename, int from_tty)
 334 {
 335   register value_ptr val;
 336   register struct type *type;
 337   register struct cleanup *old_chain;
 338   struct expression *expr;
 339
 340   if (typename != NULL)
 341     {
 342       expr = parse_expression (typename);
 343       old_chain = make_cleanup (free_current_contents, &expr);
 344       if (expr->elts[0].opcode == OP_TYPE)
 345         {
 346           /* The user expression names a type directly, just use that type. */
 347           type = expr->elts[1].type;
 348         }
 349       else
 350         {
 351           /* The user expression may name a type indirectly by naming an
 352              object of that type.  Find that indirectly named type. */
 353           val = evaluate_type (expr);
 354           type = VALUE_TYPE (val);
 355         }
 356       if (type != NULL)
 357         {
 358           recursive_dump_type (type, 0);
 359         }
 360       do_cleanups (old_chain);
 361     }
 362 }
 363 \f
 364
 365 void
 366 _initialize_typeprint (void)
 367 {
 368
 369   add_com ("ptype", class_vars, ptype_command,
 370            "Print definition of type TYPE.\n\
 371 Argument may be a type name defined by typedef, or \"struct STRUCT-TAG\"\n\
 372 or \"class CLASS-NAME\" or \"union UNION-TAG\" or \"enum ENUM-TAG\".\n\
 373 The selected stack frame's lexical context is used to look up the name.");
 374
 375   add_com ("whatis", class_vars, whatis_command,
 376            "Print data type of expression EXP.");
 377
 378 }