gdb/typeprint.c

   1 /* Language independent support for printing types for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986, 1988-1989, 1991-1995, 1998-2001, 2003, 2006-2012
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "gdb_obstack.h"
  23 #include "bfd.h"                /* Binary File Description */
  24 #include "symtab.h"
  25 #include "gdbtypes.h"
  26 #include "expression.h"
  27 #include "value.h"
  28 #include "gdbcore.h"
  29 #include "command.h"
  30 #include "gdbcmd.h"
  31 #include "target.h"
  32 #include "language.h"
  33 #include "cp-abi.h"
  34 #include "typeprint.h"
  35 #include "gdb_string.h"
  36 #include "exceptions.h"
  37 #include "valprint.h"
  38 #include <errno.h>
  39 #include <ctype.h>
  40 #include "cli/cli-utils.h"
  41
  42 extern void _initialize_typeprint (void);
  43
  44 static void ptype_command (char *, int);
  45
  46 static void whatis_command (char *, int);
  47
  48 static void whatis_exp (char *, int);
  49
  50 const struct type_print_options type_print_raw_options =
  51 {
  52   1,                            /* raw */
  53   1,                            /* print_methods */
  54   1                             /* print_typedefs */
  55 };
  56
  57 /* The default flags for 'ptype' and 'whatis'.  */
  58
  59 static struct type_print_options default_ptype_flags =
  60 {
  61   0,                            /* raw */
  62   1,                            /* print_methods */
  63   1                             /* print_typedefs */
  64 };
  65
  66 \f
  67
  68 /* Print a description of a type in the format of a
  69    typedef for the current language.
  70    NEW is the new name for a type TYPE.  */
  71
  72 void
  73 typedef_print (struct type *type, struct symbol *new, struct ui_file *stream)
  74 {
  75   LA_PRINT_TYPEDEF (type, new, stream);
  76 }
  77
  78 /* The default way to print a typedef.  */
  79
  80 void
  81 default_print_typedef (struct type *type, struct symbol *new_symbol,
  82                        struct ui_file *stream)
  83 {
  84   error (_("Language not supported."));
  85 }
  86
  87 /* Print a description of a type TYPE in the form of a declaration of a
  88    variable named VARSTRING.  (VARSTRING is demangled if necessary.)
  89    Output goes to STREAM (via stdio).
  90    If SHOW is positive, we show the contents of the outermost level
  91    of structure even if there is a type name that could be used instead.
  92    If SHOW is negative, we never show the details of elements' types.  */
  93
  94 void
  95 type_print (struct type *type, const char *varstring, struct ui_file *stream,
  96             int show)
  97 {
  98   LA_PRINT_TYPE (type, varstring, stream, show, 0, &default_ptype_flags);
  99 }
 100
 101 /* Print TYPE to a string, returning it.  The caller is responsible for
 102    freeing the string.  */
 103
 104 char *
 105 type_to_string (struct type *type)
 106 {
 107   char *s = NULL;
 108   struct ui_file *stb;
 109   struct cleanup *old_chain;
 110   volatile struct gdb_exception except;
 111
 112   stb = mem_fileopen ();
 113   old_chain = make_cleanup_ui_file_delete (stb);
 114
 115   TRY_CATCH (except, RETURN_MASK_ALL)
 116     {
 117       type_print (type, "", stb, -1);
 118       s = ui_file_xstrdup (stb, NULL);
 119     }
 120   if (except.reason < 0)
 121     s = NULL;
 122
 123   do_cleanups (old_chain);
 124
 125   return s;
 126 }
 127
 128 /* Print type of EXP, or last thing in value history if EXP == NULL.
 129    show is passed to type_print.  */
 130
 131 static void
 132 whatis_exp (char *exp, int show)
 133 {
 134   struct expression *expr;
 135   struct value *val;
 136   struct cleanup *old_chain = NULL;
 137   struct type *real_type = NULL;
 138   struct type *type;
 139   int full = 0;
 140   int top = -1;
 141   int using_enc = 0;
 142   struct value_print_options opts;
 143   struct type_print_options flags = default_ptype_flags;
 144
 145   if (exp)
 146     {
 147       if (*exp == '/')
 148         {
 149           int seen_one = 0;
 150
 151           for (++exp; *exp && !isspace (*exp); ++exp)
 152             {
 153               switch (*exp)
 154                 {
 155                 case 'r':
 156                   flags.raw = 1;
 157                   break;
 158                 case 'm':
 159                   flags.print_methods = 0;
 160                   break;
 161                 case 'M':
 162                   flags.print_methods = 1;
 163                   break;
 164                 case 't':
 165                   flags.print_typedefs = 0;
 166                   break;
 167                 case 'T':
 168                   flags.print_typedefs = 1;
 169                   break;
 170                 default:
 171                   error (_("unrecognized flag '%c'"), *exp);
 172                 }
 173               seen_one = 1;
 174             }
 175
 176           if (!*exp && !seen_one)
 177             error (_("flag expected"));
 178           if (!isspace (*exp))
 179             error (_("expected space after format"));
 180           exp = skip_spaces (exp);
 181         }
 182
 183       expr = parse_expression (exp);
 184       old_chain = make_cleanup (free_current_contents, &expr);
 185       val = evaluate_type (expr);
 186     }
 187   else
 188     val = access_value_history (0);
 189
 190   type = value_type (val);
 191
 192   get_user_print_options (&opts);
 193   if (opts.objectprint)
 194     {
 195       if (((TYPE_CODE (type) == TYPE_CODE_PTR)
 196            || (TYPE_CODE (type) == TYPE_CODE_REF))
 197           && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS))
 198         real_type = value_rtti_indirect_type (val, &full, &top, &using_enc);
 199       else if (TYPE_CODE (type) == TYPE_CODE_CLASS)
 200         real_type = value_rtti_type (val, &full, &top, &using_enc);
 201     }
 202
 203   printf_filtered ("type = ");
 204
 205   if (real_type)
 206     {
 207       printf_filtered ("/* real type = ");
 208       type_print (real_type, "", gdb_stdout, -1);
 209       if (! full)
 210         printf_filtered (" (incomplete object)");
 211       printf_filtered (" */\n");
 212     }
 213
 214   LA_PRINT_TYPE (type, "", gdb_stdout, show, 0, &flags);
 215   printf_filtered ("\n");
 216
 217   if (exp)
 218     do_cleanups (old_chain);
 219 }
 220
 221 static void
 222 whatis_command (char *exp, int from_tty)
 223 {
 224   /* Most of the time users do not want to see all the fields
 225      in a structure.  If they do they can use the "ptype" command.
 226      Hence the "-1" below.  */
 227   whatis_exp (exp, -1);
 228 }
 229
 230 /* TYPENAME is either the name of a type, or an expression.  */
 231
 232 static void
 233 ptype_command (char *typename, int from_tty)
 234 {
 235   whatis_exp (typename, 1);
 236 }
 237
 238 /* Print integral scalar data VAL, of type TYPE, onto stdio stream STREAM.
 239    Used to print data from type structures in a specified type.  For example,
 240    array bounds may be characters or booleans in some languages, and this
 241    allows the ranges to be printed in their "natural" form rather than as
 242    decimal integer values.
 243
 244    FIXME:  This is here simply because only the type printing routines
 245    currently use it, and it wasn't clear if it really belonged somewhere
 246    else (like printcmd.c).  There are a lot of other gdb routines that do
 247    something similar, but they are generally concerned with printing values
 248    that come from the inferior in target byte order and target size.  */
 249
 250 void
 251 print_type_scalar (struct type *type, LONGEST val, struct ui_file *stream)
 252 {
 253   unsigned int i;
 254   unsigned len;
 255
 256   CHECK_TYPEDEF (type);
 257
 258   switch (TYPE_CODE (type))
 259     {
 260
 261     case TYPE_CODE_ENUM:
 262       len = TYPE_NFIELDS (type);
 263       for (i = 0; i < len; i++)
 264         {
 265           if (TYPE_FIELD_ENUMVAL (type, i) == val)
 266             {
 267               break;
 268             }
 269         }
 270       if (i < len)
 271         {
 272           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 273         }
 274       else
 275         {
 276           print_longest (stream, 'd', 0, val);
 277         }
 278       break;
 279
 280     case TYPE_CODE_INT:
 281       print_longest (stream, TYPE_UNSIGNED (type) ? 'u' : 'd', 0, val);
 282       break;
 283
 284     case TYPE_CODE_CHAR:
 285       LA_PRINT_CHAR ((unsigned char) val, type, stream);
 286       break;
 287
 288     case TYPE_CODE_BOOL:
 289       fprintf_filtered (stream, val ? "TRUE" : "FALSE");
 290       break;
 291
 292     case TYPE_CODE_RANGE:
 293       print_type_scalar (TYPE_TARGET_TYPE (type), val, stream);
 294       return;
 295
 296     case TYPE_CODE_UNDEF:
 297     case TYPE_CODE_PTR:
 298     case TYPE_CODE_ARRAY:
 299     case TYPE_CODE_STRUCT:
 300     case TYPE_CODE_UNION:
 301     case TYPE_CODE_FUNC:
 302     case TYPE_CODE_FLT:
 303     case TYPE_CODE_VOID:
 304     case TYPE_CODE_SET:
 305     case TYPE_CODE_STRING:
 306     case TYPE_CODE_ERROR:
 307     case TYPE_CODE_MEMBERPTR:
 308     case TYPE_CODE_METHODPTR:
 309     case TYPE_CODE_METHOD:
 310     case TYPE_CODE_REF:
 311     case TYPE_CODE_NAMESPACE:
 312       error (_("internal error: unhandled type in print_type_scalar"));
 313       break;
 314
 315     default:
 316       error (_("Invalid type code in symbol table."));
 317     }
 318   gdb_flush (stream);
 319 }
 320
 321 /* Dump details of a type specified either directly or indirectly.
 322    Uses the same sort of type lookup mechanism as ptype_command()
 323    and whatis_command().  */
 324
 325 void
 326 maintenance_print_type (char *typename, int from_tty)
 327 {
 328   struct value *val;
 329   struct type *type;
 330   struct cleanup *old_chain;
 331   struct expression *expr;
 332
 333   if (typename != NULL)
 334     {
 335       expr = parse_expression (typename);
 336       old_chain = make_cleanup (free_current_contents, &expr);
 337       if (expr->elts[0].opcode == OP_TYPE)
 338         {
 339           /* The user expression names a type directly, just use that type.  */
 340           type = expr->elts[1].type;
 341         }
 342       else
 343         {
 344           /* The user expression may name a type indirectly by naming an
 345              object of that type.  Find that indirectly named type.  */
 346           val = evaluate_type (expr);
 347           type = value_type (val);
 348         }
 349       if (type != NULL)
 350         {
 351           recursive_dump_type (type, 0);
 352         }
 353       do_cleanups (old_chain);
 354     }
 355 }
 356 \f
 357
 358 struct cmd_list_element *setprinttypelist;
 359
 360 struct cmd_list_element *showprinttypelist;
 361
 362 static void
 363 set_print_type (char *arg, int from_tty)
 364 {
 365   printf_unfiltered (
 366      "\"set print type\" must be followed by the name of a subcommand.\n");
 367   help_list (setprintlist, "set print type ", -1, gdb_stdout);
 368 }
 369
 370 static void
 371 show_print_type (char *args, int from_tty)
 372 {
 373   cmd_show_list (showprinttypelist, from_tty, "");
 374 }
 375
 376 static int print_methods = 1;
 377
 378 static void
 379 set_print_type_methods (char *args, int from_tty, struct cmd_list_element *c)
 380 {
 381   default_ptype_flags.print_methods = print_methods;
 382 }
 383
 384 static void
 385 show_print_type_methods (struct ui_file *file, int from_tty,
 386                          struct cmd_list_element *c, const char *value)
 387 {
 388   fprintf_filtered (file, _("Printing of methods defined in a class in %s\n"),
 389                     value);
 390 }
 391
 392 static int print_typedefs = 1;
 393
 394 static void
 395 set_print_type_typedefs (char *args, int from_tty, struct cmd_list_element *c)
 396 {
 397   default_ptype_flags.print_typedefs = print_typedefs;
 398 }
 399
 400 static void
 401 show_print_type_typedefs (struct ui_file *file, int from_tty,
 402                          struct cmd_list_element *c, const char *value)
 403 {
 404   fprintf_filtered (file, _("Printing of typedefs defined in a class in %s\n"),
 405                     value);
 406 }
 407
 408 void
 409 _initialize_typeprint (void)
 410 {
 411   add_com ("ptype", class_vars, ptype_command, _("\
 412 Print definition of type TYPE.\n\
 413 Usage: ptype[/FLAGS] TYPE-NAME | EXPRESSION\n\
 414 Argument may be a type name defined by typedef, or \"struct STRUCT-TAG\"\n\
 415 or \"class CLASS-NAME\" or \"union UNION-TAG\" or \"enum ENUM-TAG\".\n\
 416 The selected stack frame's lexical context is used to look up the name.\n\
 417 Contrary to \"whatis\", \"ptype\" always unrolls any typedefs.\n\
 418 \n\
 419 Available FLAGS are:\n\
 420   /r    print in \"raw\" form; do not substitute typedefs\n\
 421   /m    do not print methods defined in a class\n\
 422   /M    print methods defined in a class\n\
 423   /t    do not print typedefs defined in a class\n\
 424   /T    print typedefs defined in a class"));
 425
 426   add_com ("whatis", class_vars, whatis_command,
 427            _("Print data type of expression EXP.\n\
 428 Only one level of typedefs is unrolled.  See also \"ptype\"."));
 429
 430   add_prefix_cmd ("type", no_class, show_print_type,
 431                   _("Generic command for showing type-printing settings."),
 432                   &showprinttypelist, "show print type ", 0, &showprintlist);
 433   add_prefix_cmd ("type", no_class, set_print_type,
 434                   _("Generic command for setting how types print."),
 435                   &setprinttypelist, "show print type ", 0, &setprintlist);
 436
 437   add_setshow_boolean_cmd ("methods", no_class, &print_methods,
 438                            _("\
 439 Set printing of methods defined in classes."), _("\
 440 Show printing of methods defined in classes."), NULL,
 441                            set_print_type_methods,
 442                            show_print_type_methods,
 443                            &setprinttypelist, &showprinttypelist);
 444   add_setshow_boolean_cmd ("typedefs", no_class, &print_typedefs,
 445                            _("\
 446 Set printing of typedefs defined in classes."), _("\
 447 Show printing of typedefs defined in classes."), NULL,
 448                            set_print_type_typedefs,
 449                            show_print_type_typedefs,
 450                            &setprinttypelist, &showprinttypelist);
 451 }