gdb/c-valprint.c

   1 /* Support for printing C values for GDB, the GNU debugger.
   2    Copyright 1986, 1988, 1989, 1991-1997, 2000
   3    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 "symtab.h"
  24 #include "gdbtypes.h"
  25 #include "expression.h"
  26 #include "value.h"
  27 #include "demangle.h"
  28 #include "valprint.h"
  29 #include "language.h"
  30 #include "c-lang.h"
  31 \f
  32
  33 /* Print data of type TYPE located at VALADDR (within GDB), which came from
  34    the inferior at address ADDRESS, onto stdio stream STREAM according to
  35    FORMAT (a letter or 0 for natural format).  The data at VALADDR is in
  36    target byte order.
  37
  38    If the data are a string pointer, returns the number of string characters
  39    printed.
  40
  41    If DEREF_REF is nonzero, then dereference references, otherwise just print
  42    them like pointers.
  43
  44    The PRETTY parameter controls prettyprinting.  */
  45
  46 int
  47 c_val_print (type, valaddr, embedded_offset, address, stream, format, deref_ref, recurse,
  48              pretty)
  49      struct type *type;
  50      char *valaddr;
  51      int embedded_offset;
  52      CORE_ADDR address;
  53      struct ui_file *stream;
  54      int format;
  55      int deref_ref;
  56      int recurse;
  57      enum val_prettyprint pretty;
  58 {
  59   register unsigned int i = 0;  /* Number of characters printed */
  60   unsigned len;
  61   struct type *elttype;
  62   unsigned eltlen;
  63   LONGEST val;
  64   CORE_ADDR addr;
  65
  66   CHECK_TYPEDEF (type);
  67   switch (TYPE_CODE (type))
  68     {
  69     case TYPE_CODE_ARRAY:
  70       elttype = check_typedef (TYPE_TARGET_TYPE (type));
  71       if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
  72         {
  73           eltlen = TYPE_LENGTH (elttype);
  74           len = TYPE_LENGTH (type) / eltlen;
  75           if (prettyprint_arrays)
  76             {
  77               print_spaces_filtered (2 + 2 * recurse, stream);
  78             }
  79           /* For an array of chars, print with string syntax.  */
  80           if (eltlen == 1 &&
  81               ((TYPE_CODE (elttype) == TYPE_CODE_INT)
  82                || ((current_language->la_language == language_m2)
  83                    && (TYPE_CODE (elttype) == TYPE_CODE_CHAR)))
  84               && (format == 0 || format == 's'))
  85             {
  86               /* If requested, look for the first null char and only print
  87                  elements up to it.  */
  88               if (stop_print_at_null)
  89                 {
  90                   unsigned int temp_len;
  91
  92                   /* Look for a NULL char. */
  93                   for (temp_len = 0;
  94                        (valaddr + embedded_offset)[temp_len]
  95                        && temp_len < len && temp_len < print_max;
  96                        temp_len++);
  97                   len = temp_len;
  98                 }
  99
 100               LA_PRINT_STRING (stream, valaddr + embedded_offset, len, eltlen, 0);
 101               i = len;
 102             }
 103           else
 104             {
 105               fprintf_filtered (stream, "{");
 106               /* If this is a virtual function table, print the 0th
 107                  entry specially, and the rest of the members normally.  */
 108               if (cp_is_vtbl_ptr_type (elttype))
 109                 {
 110                   i = 1;
 111                   fprintf_filtered (stream, "%d vtable entries", len - 1);
 112                 }
 113               else
 114                 {
 115                   i = 0;
 116                 }
 117               val_print_array_elements (type, valaddr + embedded_offset, address, stream,
 118                                      format, deref_ref, recurse, pretty, i);
 119               fprintf_filtered (stream, "}");
 120             }
 121           break;
 122         }
 123       /* Array of unspecified length: treat like pointer to first elt.  */
 124       addr = address;
 125       goto print_unpacked_pointer;
 126
 127     case TYPE_CODE_PTR:
 128       if (format && format != 's')
 129         {
 130           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 131           break;
 132         }
 133       if (vtblprint && cp_is_vtbl_ptr_type (type))
 134         {
 135           /* Print the unmangled name if desired.  */
 136           /* Print vtable entry - we only get here if we ARE using
 137              -fvtable_thunks.  (Otherwise, look under TYPE_CODE_STRUCT.) */
 138           CORE_ADDR addr
 139             = extract_typed_address (valaddr + embedded_offset, type);
 140           print_address_demangle (addr, stream, demangle);
 141           break;
 142         }
 143       elttype = check_typedef (TYPE_TARGET_TYPE (type));
 144       if (TYPE_CODE (elttype) == TYPE_CODE_METHOD)
 145         {
 146           cp_print_class_method (valaddr + embedded_offset, type, stream);
 147         }
 148       else if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
 149         {
 150           cp_print_class_member (valaddr + embedded_offset,
 151                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 152                                  stream, "&");
 153         }
 154       else
 155         {
 156           addr = unpack_pointer (type, valaddr + embedded_offset);
 157         print_unpacked_pointer:
 158           elttype = check_typedef (TYPE_TARGET_TYPE (type));
 159
 160           if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
 161             {
 162               /* Try to print what function it points to.  */
 163               print_address_demangle (addr, stream, demangle);
 164               /* Return value is irrelevant except for string pointers.  */
 165               return (0);
 166             }
 167
 168           if (addressprint && format != 's')
 169             {
 170               print_address_numeric (addr, 1, stream);
 171             }
 172
 173           /* For a pointer to char or unsigned char, also print the string
 174              pointed to, unless pointer is null.  */
 175           /* FIXME: need to handle wchar_t here... */
 176
 177           if (TYPE_LENGTH (elttype) == 1
 178               && TYPE_CODE (elttype) == TYPE_CODE_INT
 179               && (format == 0 || format == 's')
 180               && addr != 0)
 181             {
 182               i = val_print_string (addr, -1, TYPE_LENGTH (elttype), stream);
 183             }
 184           else if (cp_is_vtbl_member (type))
 185             {
 186               /* print vtbl's nicely */
 187               CORE_ADDR vt_address = unpack_pointer (type, valaddr + embedded_offset);
 188
 189               struct minimal_symbol *msymbol =
 190               lookup_minimal_symbol_by_pc (vt_address);
 191               if ((msymbol != NULL) &&
 192                   (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
 193                 {
 194                   fputs_filtered (" <", stream);
 195                   fputs_filtered (SYMBOL_SOURCE_NAME (msymbol), stream);
 196                   fputs_filtered (">", stream);
 197                 }
 198               if (vt_address && vtblprint)
 199                 {
 200                   value_ptr vt_val;
 201                   struct symbol *wsym = (struct symbol *) NULL;
 202                   struct type *wtype;
 203                   struct symtab *s;
 204                   struct block *block = (struct block *) NULL;
 205                   int is_this_fld;
 206
 207                   if (msymbol != NULL)
 208                     wsym = lookup_symbol (SYMBOL_NAME (msymbol), block,
 209                                           VAR_NAMESPACE, &is_this_fld, &s);
 210
 211                   if (wsym)
 212                     {
 213                       wtype = SYMBOL_TYPE (wsym);
 214                     }
 215                   else
 216                     {
 217                       wtype = TYPE_TARGET_TYPE (type);
 218                     }
 219                   vt_val = value_at (wtype, vt_address, NULL);
 220                   val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val), 0,
 221                              VALUE_ADDRESS (vt_val), stream, format,
 222                              deref_ref, recurse + 1, pretty);
 223                   if (pretty)
 224                     {
 225                       fprintf_filtered (stream, "\n");
 226                       print_spaces_filtered (2 + 2 * recurse, stream);
 227                     }
 228                 }
 229             }
 230
 231           /* Return number of characters printed, including the terminating
 232              '\0' if we reached the end.  val_print_string takes care including
 233              the terminating '\0' if necessary.  */
 234           return i;
 235         }
 236       break;
 237
 238     case TYPE_CODE_MEMBER:
 239       error ("not implemented: member type in c_val_print");
 240       break;
 241
 242     case TYPE_CODE_REF:
 243       elttype = check_typedef (TYPE_TARGET_TYPE (type));
 244       if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
 245         {
 246           cp_print_class_member (valaddr + embedded_offset,
 247                                  TYPE_DOMAIN_TYPE (elttype),
 248                                  stream, "");
 249           break;
 250         }
 251       if (addressprint)
 252         {
 253           CORE_ADDR addr
 254             = extract_typed_address (valaddr + embedded_offset, type);
 255           fprintf_filtered (stream, "@");
 256           print_address_numeric (addr, 1, stream);
 257           if (deref_ref)
 258             fputs_filtered (": ", stream);
 259         }
 260       /* De-reference the reference.  */
 261       if (deref_ref)
 262         {
 263           if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
 264             {
 265               value_ptr deref_val =
 266               value_at
 267               (TYPE_TARGET_TYPE (type),
 268                unpack_pointer (lookup_pointer_type (builtin_type_void),
 269                                valaddr + embedded_offset),
 270                NULL);
 271               val_print (VALUE_TYPE (deref_val),
 272                          VALUE_CONTENTS (deref_val),
 273                          0,
 274                          VALUE_ADDRESS (deref_val),
 275                          stream,
 276                          format,
 277                          deref_ref,
 278                          recurse,
 279                          pretty);
 280             }
 281           else
 282             fputs_filtered ("???", stream);
 283         }
 284       break;
 285
 286     case TYPE_CODE_UNION:
 287       if (recurse && !unionprint)
 288         {
 289           fprintf_filtered (stream, "{...}");
 290           break;
 291         }
 292       /* Fall through.  */
 293     case TYPE_CODE_STRUCT:
 294       if (vtblprint && cp_is_vtbl_ptr_type (type))
 295         {
 296           /* Print the unmangled name if desired.  */
 297           /* Print vtable entry - we only get here if NOT using
 298              -fvtable_thunks.  (Otherwise, look under TYPE_CODE_PTR.) */
 299           int offset = (embedded_offset +
 300                         TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8);
 301           struct type *field_type = TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET);
 302           CORE_ADDR addr
 303             = extract_typed_address (valaddr + offset, field_type);
 304
 305           print_address_demangle (addr, stream, demangle);
 306         }
 307       else
 308         cp_print_value_fields (type, type, valaddr, embedded_offset, address, stream, format,
 309                                recurse, pretty, NULL, 0);
 310       break;
 311
 312     case TYPE_CODE_ENUM:
 313       if (format)
 314         {
 315           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 316           break;
 317         }
 318       len = TYPE_NFIELDS (type);
 319       val = unpack_long (type, valaddr + embedded_offset);
 320       for (i = 0; i < len; i++)
 321         {
 322           QUIT;
 323           if (val == TYPE_FIELD_BITPOS (type, i))
 324             {
 325               break;
 326             }
 327         }
 328       if (i < len)
 329         {
 330           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 331         }
 332       else
 333         {
 334           print_longest (stream, 'd', 0, val);
 335         }
 336       break;
 337
 338     case TYPE_CODE_FUNC:
 339       if (format)
 340         {
 341           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 342           break;
 343         }
 344       /* FIXME, we should consider, at least for ANSI C language, eliminating
 345          the distinction made between FUNCs and POINTERs to FUNCs.  */
 346       fprintf_filtered (stream, "{");
 347       type_print (type, "", stream, -1);
 348       fprintf_filtered (stream, "} ");
 349       /* Try to print what function it points to, and its address.  */
 350       print_address_demangle (address, stream, demangle);
 351       break;
 352
 353     case TYPE_CODE_BOOL:
 354       format = format ? format : output_format;
 355       if (format)
 356         print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 357       else
 358         {
 359           val = unpack_long (type, valaddr + embedded_offset);
 360           if (val == 0)
 361             fputs_filtered ("false", stream);
 362           else if (val == 1)
 363             fputs_filtered ("true", stream);
 364           else
 365             print_longest (stream, 'd', 0, val);
 366         }
 367       break;
 368
 369     case TYPE_CODE_RANGE:
 370       /* FIXME: create_range_type does not set the unsigned bit in a
 371          range type (I think it probably should copy it from the target
 372          type), so we won't print values which are too large to
 373          fit in a signed integer correctly.  */
 374       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
 375          print with the target type, though, because the size of our type
 376          and the target type might differ).  */
 377       /* FALLTHROUGH */
 378
 379     case TYPE_CODE_INT:
 380       format = format ? format : output_format;
 381       if (format)
 382         {
 383           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 384         }
 385       else
 386         {
 387           val_print_type_code_int (type, valaddr + embedded_offset, stream);
 388           /* C and C++ has no single byte int type, char is used instead.
 389              Since we don't know whether the value is really intended to
 390              be used as an integer or a character, print the character
 391              equivalent as well. */
 392           if (TYPE_LENGTH (type) == 1)
 393             {
 394               fputs_filtered (" ", stream);
 395               LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr + embedded_offset),
 396                              stream);
 397             }
 398         }
 399       break;
 400
 401     case TYPE_CODE_CHAR:
 402       format = format ? format : output_format;
 403       if (format)
 404         {
 405           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 406         }
 407       else
 408         {
 409           val = unpack_long (type, valaddr + embedded_offset);
 410           if (TYPE_UNSIGNED (type))
 411             fprintf_filtered (stream, "%u", (unsigned int) val);
 412           else
 413             fprintf_filtered (stream, "%d", (int) val);
 414           fputs_filtered (" ", stream);
 415           LA_PRINT_CHAR ((unsigned char) val, stream);
 416         }
 417       break;
 418
 419     case TYPE_CODE_FLT:
 420       if (format)
 421         {
 422           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 423         }
 424       else
 425         {
 426           print_floating (valaddr + embedded_offset, type, stream);
 427         }
 428       break;
 429
 430     case TYPE_CODE_METHOD:
 431       cp_print_class_method (valaddr + embedded_offset, lookup_pointer_type (type), stream);
 432       break;
 433
 434     case TYPE_CODE_VOID:
 435       fprintf_filtered (stream, "void");
 436       break;
 437
 438     case TYPE_CODE_ERROR:
 439       fprintf_filtered (stream, "<error type>");
 440       break;
 441
 442     case TYPE_CODE_UNDEF:
 443       /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
 444          dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
 445          and no complete type for struct foo in that file.  */
 446       fprintf_filtered (stream, "<incomplete type>");
 447       break;
 448
 449     default:
 450       error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
 451     }
 452   gdb_flush (stream);
 453   return (0);
 454 }
 455 \f
 456 int
 457 c_value_print (val, stream, format, pretty)
 458      value_ptr val;
 459      struct ui_file *stream;
 460      int format;
 461      enum val_prettyprint pretty;
 462 {
 463   struct type *type = VALUE_TYPE (val);
 464   struct type *real_type;
 465   int full, top, using_enc;
 466
 467   /* If it is a pointer, indicate what it points to.
 468
 469      Print type also if it is a reference.
 470
 471      C++: if it is a member pointer, we will take care
 472      of that when we print it.  */
 473   if (TYPE_CODE (type) == TYPE_CODE_PTR ||
 474       TYPE_CODE (type) == TYPE_CODE_REF)
 475     {
 476       /* Hack:  remove (char *) for char strings.  Their
 477          type is indicated by the quoted string anyway. */
 478       if (TYPE_CODE (type) == TYPE_CODE_PTR &&
 479           TYPE_NAME (type) == NULL &&
 480           TYPE_NAME (TYPE_TARGET_TYPE (type)) != NULL &&
 481           STREQ (TYPE_NAME (TYPE_TARGET_TYPE (type)), "char"))
 482         {
 483           /* Print nothing */
 484         }
 485       else if (objectprint && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS))
 486         {
 487
 488           if (TYPE_CODE(type) == TYPE_CODE_REF)
 489             {
 490               /* Copy value, change to pointer, so we don't get an
 491                * error about a non-pointer type in value_rtti_target_type
 492                */
 493               value_ptr temparg;
 494               temparg=value_copy(val);
 495               VALUE_TYPE (temparg) = lookup_pointer_type(TYPE_TARGET_TYPE(type));
 496               val=temparg;
 497             }
 498           /* Pointer to class, check real type of object */
 499           fprintf_filtered (stream, "(");
 500           real_type = value_rtti_target_type (val, &full, &top, &using_enc);
 501           if (real_type)
 502             {
 503               /* RTTI entry found */
 504               if (TYPE_CODE (type) == TYPE_CODE_PTR)
 505                 {
 506                   /* create a pointer type pointing to the real type */
 507                   type = lookup_pointer_type (real_type);
 508                 }
 509               else
 510                 {
 511                   /* create a reference type referencing the real type */
 512                   type = lookup_reference_type (real_type);
 513                 }
 514               /* JYG: Need to adjust pointer value. */
 515               val->aligner.contents[0] -= top;
 516
 517               /* Note: When we look up RTTI entries, we don't get any
 518                  information on const or volatile attributes */
 519             }
 520           type_print (type, "", stream, -1);
 521           fprintf_filtered (stream, ") ");
 522         }
 523       else
 524         {
 525           /* normal case */
 526           fprintf_filtered (stream, "(");
 527           type_print (type, "", stream, -1);
 528           fprintf_filtered (stream, ") ");
 529         }
 530     }
 531   if (objectprint && (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_CLASS))
 532     {
 533       /* Attempt to determine real type of object */
 534       real_type = value_rtti_type (val, &full, &top, &using_enc);
 535       if (real_type)
 536         {
 537           /* We have RTTI information, so use it */
 538           val = value_full_object (val, real_type, full, top, using_enc);
 539           fprintf_filtered (stream, "(%s%s) ",
 540                             TYPE_NAME (real_type),
 541                             full ? "" : " [incomplete object]");
 542           /* Print out object: enclosing type is same as real_type if full */
 543           return val_print (VALUE_ENCLOSING_TYPE (val), VALUE_CONTENTS_ALL (val), 0,
 544                          VALUE_ADDRESS (val), stream, format, 1, 0, pretty);
 545           /* Note: When we look up RTTI entries, we don't get any information on
 546              const or volatile attributes */
 547         }
 548       else if (type != VALUE_ENCLOSING_TYPE (val))
 549         {
 550           /* No RTTI information, so let's do our best */
 551           fprintf_filtered (stream, "(%s ?) ",
 552                             TYPE_NAME (VALUE_ENCLOSING_TYPE (val)));
 553           return val_print (VALUE_ENCLOSING_TYPE (val), VALUE_CONTENTS_ALL (val), 0,
 554                          VALUE_ADDRESS (val), stream, format, 1, 0, pretty);
 555         }
 556       /* Otherwise, we end up at the return outside this "if" */
 557     }
 558
 559   return val_print (type, VALUE_CONTENTS_ALL (val), VALUE_EMBEDDED_OFFSET (val),
 560                     VALUE_ADDRESS (val),
 561                     stream, format, 1, 0, pretty);
 562 }