gdb/c-valprint.c

   1 /* Support for printing C values for GDB, the GNU debugger.
   2
   3    Copyright 1986, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996,
   4    1997, 1998, 1999, 2000, 2001, 2003 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 2 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, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #include "defs.h"
  24 #include "gdb_string.h"
  25 #include "symtab.h"
  26 #include "gdbtypes.h"
  27 #include "expression.h"
  28 #include "value.h"
  29 #include "valprint.h"
  30 #include "language.h"
  31 #include "c-lang.h"
  32 #include "cp-abi.h"
  33 \f
  34
  35 /* Print function pointer with inferior address ADDRESS onto stdio
  36    stream STREAM.  */
  37
  38 static void
  39 print_function_pointer_address (CORE_ADDR address, struct ui_file *stream)
  40 {
  41   CORE_ADDR func_addr = CONVERT_FROM_FUNC_PTR_ADDR (address);
  42
  43   /* If the function pointer is represented by a description, print the
  44      address of the description.  */
  45   if (addressprint && func_addr != address)
  46     {
  47       fputs_filtered ("@", stream);
  48       print_address_numeric (address, 1, stream);
  49       fputs_filtered (": ", stream);
  50     }
  51   print_address_demangle (func_addr, stream, demangle);
  52 }
  53
  54
  55 /* Print data of type TYPE located at VALADDR (within GDB), which came from
  56    the inferior at address ADDRESS, onto stdio stream STREAM according to
  57    FORMAT (a letter or 0 for natural format).  The data at VALADDR is in
  58    target byte order.
  59
  60    If the data are a string pointer, returns the number of string characters
  61    printed.
  62
  63    If DEREF_REF is nonzero, then dereference references, otherwise just print
  64    them like pointers.
  65
  66    The PRETTY parameter controls prettyprinting.  */
  67
  68 int
  69 c_val_print (struct type *type, char *valaddr, int embedded_offset,
  70              CORE_ADDR address, struct ui_file *stream, int format,
  71              int deref_ref, int recurse, enum val_prettyprint pretty)
  72 {
  73   register unsigned int i = 0;  /* Number of characters printed */
  74   unsigned len;
  75   struct type *elttype;
  76   unsigned eltlen;
  77   LONGEST val;
  78   CORE_ADDR addr;
  79
  80   CHECK_TYPEDEF (type);
  81   switch (TYPE_CODE (type))
  82     {
  83     case TYPE_CODE_ARRAY:
  84       elttype = check_typedef (TYPE_TARGET_TYPE (type));
  85       if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
  86         {
  87           eltlen = TYPE_LENGTH (elttype);
  88           len = TYPE_LENGTH (type) / eltlen;
  89           if (prettyprint_arrays)
  90             {
  91               print_spaces_filtered (2 + 2 * recurse, stream);
  92             }
  93           /* For an array of chars, print with string syntax.  */
  94           if (eltlen == 1 &&
  95               ((TYPE_CODE (elttype) == TYPE_CODE_INT)
  96                || ((current_language->la_language == language_m2)
  97                    && (TYPE_CODE (elttype) == TYPE_CODE_CHAR)))
  98               && (format == 0 || format == 's'))
  99             {
 100               /* If requested, look for the first null char and only print
 101                  elements up to it.  */
 102               if (stop_print_at_null)
 103                 {
 104                   unsigned int temp_len;
 105
 106                   /* Look for a NULL char. */
 107                   for (temp_len = 0;
 108                        (valaddr + embedded_offset)[temp_len]
 109                        && temp_len < len && temp_len < print_max;
 110                        temp_len++);
 111                   len = temp_len;
 112                 }
 113
 114               LA_PRINT_STRING (stream, valaddr + embedded_offset, len, eltlen, 0);
 115               i = len;
 116             }
 117           else
 118             {
 119               fprintf_filtered (stream, "{");
 120               /* If this is a virtual function table, print the 0th
 121                  entry specially, and the rest of the members normally.  */
 122               if (cp_is_vtbl_ptr_type (elttype))
 123                 {
 124                   i = 1;
 125                   fprintf_filtered (stream, "%d vtable entries", len - 1);
 126                 }
 127               else
 128                 {
 129                   i = 0;
 130                 }
 131               val_print_array_elements (type, valaddr + embedded_offset, address, stream,
 132                                      format, deref_ref, recurse, pretty, i);
 133               fprintf_filtered (stream, "}");
 134             }
 135           break;
 136         }
 137       /* Array of unspecified length: treat like pointer to first elt.  */
 138       addr = address;
 139       goto print_unpacked_pointer;
 140
 141     case TYPE_CODE_PTR:
 142       if (format && format != 's')
 143         {
 144           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 145           break;
 146         }
 147       if (vtblprint && cp_is_vtbl_ptr_type (type))
 148         {
 149           /* Print the unmangled name if desired.  */
 150           /* Print vtable entry - we only get here if we ARE using
 151              -fvtable_thunks.  (Otherwise, look under TYPE_CODE_STRUCT.) */
 152           CORE_ADDR addr
 153             = extract_typed_address (valaddr + embedded_offset, type);
 154           print_function_pointer_address (addr, stream);
 155           break;
 156         }
 157       elttype = check_typedef (TYPE_TARGET_TYPE (type));
 158       if (TYPE_CODE (elttype) == TYPE_CODE_METHOD)
 159         {
 160           cp_print_class_method (valaddr + embedded_offset, type, stream);
 161         }
 162       else if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
 163         {
 164           cp_print_class_member (valaddr + embedded_offset,
 165                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 166                                  stream, "&");
 167         }
 168       else
 169         {
 170           addr = unpack_pointer (type, valaddr + embedded_offset);
 171         print_unpacked_pointer:
 172
 173           if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
 174             {
 175               /* Try to print what function it points to.  */
 176               print_function_pointer_address (addr, stream);
 177               /* Return value is irrelevant except for string pointers.  */
 178               return (0);
 179             }
 180
 181           if (addressprint && format != 's')
 182             {
 183               print_address_numeric (addr, 1, stream);
 184             }
 185
 186           /* For a pointer to char or unsigned char, also print the string
 187              pointed to, unless pointer is null.  */
 188           /* FIXME: need to handle wchar_t here... */
 189
 190           if (TYPE_LENGTH (elttype) == 1
 191               && TYPE_CODE (elttype) == TYPE_CODE_INT
 192               && (format == 0 || format == 's')
 193               && addr != 0)
 194             {
 195               i = val_print_string (addr, -1, TYPE_LENGTH (elttype), stream);
 196             }
 197           else if (cp_is_vtbl_member (type))
 198             {
 199               /* print vtbl's nicely */
 200               CORE_ADDR vt_address = unpack_pointer (type, valaddr + embedded_offset);
 201
 202               struct minimal_symbol *msymbol =
 203               lookup_minimal_symbol_by_pc (vt_address);
 204               if ((msymbol != NULL) &&
 205                   (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
 206                 {
 207                   fputs_filtered (" <", stream);
 208                   fputs_filtered (SYMBOL_PRINT_NAME (msymbol), stream);
 209                   fputs_filtered (">", stream);
 210                 }
 211               if (vt_address && vtblprint)
 212                 {
 213                   struct value *vt_val;
 214                   struct symbol *wsym = (struct symbol *) NULL;
 215                   struct type *wtype;
 216                   struct block *block = (struct block *) NULL;
 217                   int is_this_fld;
 218
 219                   if (msymbol != NULL)
 220                     wsym = lookup_symbol (DEPRECATED_SYMBOL_NAME (msymbol), block,
 221                                           VAR_DOMAIN, &is_this_fld, NULL);
 222
 223                   if (wsym)
 224                     {
 225                       wtype = SYMBOL_TYPE (wsym);
 226                     }
 227                   else
 228                     {
 229                       wtype = TYPE_TARGET_TYPE (type);
 230                     }
 231                   vt_val = value_at (wtype, vt_address, NULL);
 232                   val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val), 0,
 233                              VALUE_ADDRESS (vt_val), stream, format,
 234                              deref_ref, recurse + 1, pretty);
 235                   if (pretty)
 236                     {
 237                       fprintf_filtered (stream, "\n");
 238                       print_spaces_filtered (2 + 2 * recurse, stream);
 239                     }
 240                 }
 241             }
 242
 243           /* Return number of characters printed, including the terminating
 244              '\0' if we reached the end.  val_print_string takes care including
 245              the terminating '\0' if necessary.  */
 246           return i;
 247         }
 248       break;
 249
 250     case TYPE_CODE_MEMBER:
 251       error ("not implemented: member type in c_val_print");
 252       break;
 253
 254     case TYPE_CODE_REF:
 255       elttype = check_typedef (TYPE_TARGET_TYPE (type));
 256       if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
 257         {
 258           cp_print_class_member (valaddr + embedded_offset,
 259                                  TYPE_DOMAIN_TYPE (elttype),
 260                                  stream, "");
 261           break;
 262         }
 263       if (addressprint)
 264         {
 265           CORE_ADDR addr
 266             = extract_typed_address (valaddr + embedded_offset, type);
 267           fprintf_filtered (stream, "@");
 268           print_address_numeric (addr, 1, stream);
 269           if (deref_ref)
 270             fputs_filtered (": ", stream);
 271         }
 272       /* De-reference the reference.  */
 273       if (deref_ref)
 274         {
 275           if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
 276             {
 277               struct value *deref_val =
 278               value_at
 279               (TYPE_TARGET_TYPE (type),
 280                unpack_pointer (lookup_pointer_type (builtin_type_void),
 281                                valaddr + embedded_offset),
 282                NULL);
 283               val_print (VALUE_TYPE (deref_val),
 284                          VALUE_CONTENTS (deref_val),
 285                          0,
 286                          VALUE_ADDRESS (deref_val),
 287                          stream,
 288                          format,
 289                          deref_ref,
 290                          recurse,
 291                          pretty);
 292             }
 293           else
 294             fputs_filtered ("???", stream);
 295         }
 296       break;
 297
 298     case TYPE_CODE_UNION:
 299       if (recurse && !unionprint)
 300         {
 301           fprintf_filtered (stream, "{...}");
 302           break;
 303         }
 304       /* Fall through.  */
 305     case TYPE_CODE_STRUCT:
 306       /*FIXME: Abstract this away */
 307       if (vtblprint && cp_is_vtbl_ptr_type (type))
 308         {
 309           /* Print the unmangled name if desired.  */
 310           /* Print vtable entry - we only get here if NOT using
 311              -fvtable_thunks.  (Otherwise, look under TYPE_CODE_PTR.) */
 312           int offset = (embedded_offset +
 313                         TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8);
 314           struct type *field_type = TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET);
 315           CORE_ADDR addr
 316             = extract_typed_address (valaddr + offset, field_type);
 317
 318           print_function_pointer_address (addr, stream);
 319         }
 320       else
 321         cp_print_value_fields (type, type, valaddr, embedded_offset, address, stream, format,
 322                                recurse, pretty, NULL, 0);
 323       break;
 324
 325     case TYPE_CODE_ENUM:
 326       if (format)
 327         {
 328           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 329           break;
 330         }
 331       len = TYPE_NFIELDS (type);
 332       val = unpack_long (type, valaddr + embedded_offset);
 333       for (i = 0; i < len; i++)
 334         {
 335           QUIT;
 336           if (val == TYPE_FIELD_BITPOS (type, i))
 337             {
 338               break;
 339             }
 340         }
 341       if (i < len)
 342         {
 343           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 344         }
 345       else
 346         {
 347           print_longest (stream, 'd', 0, val);
 348         }
 349       break;
 350
 351     case TYPE_CODE_FUNC:
 352       if (format)
 353         {
 354           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 355           break;
 356         }
 357       /* FIXME, we should consider, at least for ANSI C language, eliminating
 358          the distinction made between FUNCs and POINTERs to FUNCs.  */
 359       fprintf_filtered (stream, "{");
 360       type_print (type, "", stream, -1);
 361       fprintf_filtered (stream, "} ");
 362       /* Try to print what function it points to, and its address.  */
 363       print_address_demangle (address, stream, demangle);
 364       break;
 365
 366     case TYPE_CODE_BOOL:
 367       format = format ? format : output_format;
 368       if (format)
 369         print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 370       else
 371         {
 372           val = unpack_long (type, valaddr + embedded_offset);
 373           if (val == 0)
 374             fputs_filtered ("false", stream);
 375           else if (val == 1)
 376             fputs_filtered ("true", stream);
 377           else
 378             print_longest (stream, 'd', 0, val);
 379         }
 380       break;
 381
 382     case TYPE_CODE_RANGE:
 383       /* FIXME: create_range_type does not set the unsigned bit in a
 384          range type (I think it probably should copy it from the target
 385          type), so we won't print values which are too large to
 386          fit in a signed integer correctly.  */
 387       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
 388          print with the target type, though, because the size of our type
 389          and the target type might differ).  */
 390       /* FALLTHROUGH */
 391
 392     case TYPE_CODE_INT:
 393       format = format ? format : output_format;
 394       if (format)
 395         {
 396           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 397         }
 398       else
 399         {
 400           val_print_type_code_int (type, valaddr + embedded_offset, stream);
 401           /* C and C++ has no single byte int type, char is used instead.
 402              Since we don't know whether the value is really intended to
 403              be used as an integer or a character, print the character
 404              equivalent as well. */
 405           if (TYPE_LENGTH (type) == 1)
 406             {
 407               fputs_filtered (" ", stream);
 408               LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr + embedded_offset),
 409                              stream);
 410             }
 411         }
 412       break;
 413
 414     case TYPE_CODE_CHAR:
 415       format = format ? format : output_format;
 416       if (format)
 417         {
 418           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 419         }
 420       else
 421         {
 422           val = unpack_long (type, valaddr + embedded_offset);
 423           if (TYPE_UNSIGNED (type))
 424             fprintf_filtered (stream, "%u", (unsigned int) val);
 425           else
 426             fprintf_filtered (stream, "%d", (int) val);
 427           fputs_filtered (" ", stream);
 428           LA_PRINT_CHAR ((unsigned char) val, stream);
 429         }
 430       break;
 431
 432     case TYPE_CODE_FLT:
 433       if (format)
 434         {
 435           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 436         }
 437       else
 438         {
 439           print_floating (valaddr + embedded_offset, type, stream);
 440         }
 441       break;
 442
 443     case TYPE_CODE_METHOD:
 444       {
 445         struct value *v = value_at (type, address, NULL);
 446         cp_print_class_method (VALUE_CONTENTS (value_addr (v)),
 447                                lookup_pointer_type (type), stream);
 448         break;
 449       }
 450
 451     case TYPE_CODE_VOID:
 452       fprintf_filtered (stream, "void");
 453       break;
 454
 455     case TYPE_CODE_ERROR:
 456       fprintf_filtered (stream, "<error type>");
 457       break;
 458
 459     case TYPE_CODE_UNDEF:
 460       /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
 461          dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
 462          and no complete type for struct foo in that file.  */
 463       fprintf_filtered (stream, "<incomplete type>");
 464       break;
 465
 466     case TYPE_CODE_COMPLEX:
 467       if (format)
 468         print_scalar_formatted (valaddr + embedded_offset,
 469                                 TYPE_TARGET_TYPE (type),
 470                                 format, 0, stream);
 471       else
 472         print_floating (valaddr + embedded_offset, TYPE_TARGET_TYPE (type),
 473                         stream);
 474       fprintf_filtered (stream, " + ");
 475       if (format)
 476         print_scalar_formatted (valaddr + embedded_offset
 477                                 + TYPE_LENGTH (TYPE_TARGET_TYPE (type)),
 478                                 TYPE_TARGET_TYPE (type),
 479                                 format, 0, stream);
 480       else
 481         print_floating (valaddr + embedded_offset
 482                         + TYPE_LENGTH (TYPE_TARGET_TYPE (type)),
 483                         TYPE_TARGET_TYPE (type),
 484                         stream);
 485       fprintf_filtered (stream, " * I");
 486       break;
 487
 488     default:
 489       error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
 490     }
 491   gdb_flush (stream);
 492   return (0);
 493 }
 494 \f
 495 int
 496 c_value_print (struct value *val, struct ui_file *stream, int format,
 497                enum val_prettyprint pretty)
 498 {
 499   struct type *type = VALUE_TYPE (val);
 500   struct type *real_type;
 501   int full, top, using_enc;
 502
 503   /* If it is a pointer, indicate what it points to.
 504
 505      Print type also if it is a reference.
 506
 507      C++: if it is a member pointer, we will take care
 508      of that when we print it.  */
 509   if (TYPE_CODE (type) == TYPE_CODE_PTR ||
 510       TYPE_CODE (type) == TYPE_CODE_REF)
 511     {
 512       /* Hack:  remove (char *) for char strings.  Their
 513          type is indicated by the quoted string anyway. */
 514       if (TYPE_CODE (type) == TYPE_CODE_PTR &&
 515           TYPE_NAME (type) == NULL &&
 516           TYPE_NAME (TYPE_TARGET_TYPE (type)) != NULL &&
 517           strcmp (TYPE_NAME (TYPE_TARGET_TYPE (type)), "char") == 0)
 518         {
 519           /* Print nothing */
 520         }
 521       else if (objectprint && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS))
 522         {
 523
 524           if (TYPE_CODE(type) == TYPE_CODE_REF)
 525             {
 526               /* Copy value, change to pointer, so we don't get an
 527                * error about a non-pointer type in value_rtti_target_type
 528                */
 529               struct value *temparg;
 530               temparg=value_copy(val);
 531               VALUE_TYPE (temparg) = lookup_pointer_type(TYPE_TARGET_TYPE(type));
 532               val=temparg;
 533             }
 534           /* Pointer to class, check real type of object */
 535           fprintf_filtered (stream, "(");
 536           real_type = value_rtti_target_type (val, &full, &top, &using_enc);
 537           if (real_type)
 538             {
 539               /* RTTI entry found */
 540               if (TYPE_CODE (type) == TYPE_CODE_PTR)
 541                 {
 542                   /* create a pointer type pointing to the real type */
 543                   type = lookup_pointer_type (real_type);
 544                 }
 545               else
 546                 {
 547                   /* create a reference type referencing the real type */
 548                   type = lookup_reference_type (real_type);
 549                 }
 550               /* JYG: Need to adjust pointer value. */
 551               val->aligner.contents[0] -= top;
 552
 553               /* Note: When we look up RTTI entries, we don't get any
 554                  information on const or volatile attributes */
 555             }
 556           type_print (type, "", stream, -1);
 557           fprintf_filtered (stream, ") ");
 558         }
 559       else
 560         {
 561           /* normal case */
 562           fprintf_filtered (stream, "(");
 563           type_print (type, "", stream, -1);
 564           fprintf_filtered (stream, ") ");
 565         }
 566     }
 567   if (objectprint && (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_CLASS))
 568     {
 569       /* Attempt to determine real type of object */
 570       real_type = value_rtti_type (val, &full, &top, &using_enc);
 571       if (real_type)
 572         {
 573           /* We have RTTI information, so use it */
 574           val = value_full_object (val, real_type, full, top, using_enc);
 575           fprintf_filtered (stream, "(%s%s) ",
 576                             TYPE_NAME (real_type),
 577                             full ? "" : " [incomplete object]");
 578           /* Print out object: enclosing type is same as real_type if full */
 579           return val_print (VALUE_ENCLOSING_TYPE (val), VALUE_CONTENTS_ALL (val), 0,
 580                          VALUE_ADDRESS (val), stream, format, 1, 0, pretty);
 581           /* Note: When we look up RTTI entries, we don't get any information on
 582              const or volatile attributes */
 583         }
 584       else if (type != VALUE_ENCLOSING_TYPE (val))
 585         {
 586           /* No RTTI information, so let's do our best */
 587           fprintf_filtered (stream, "(%s ?) ",
 588                             TYPE_NAME (VALUE_ENCLOSING_TYPE (val)));
 589           return val_print (VALUE_ENCLOSING_TYPE (val), VALUE_CONTENTS_ALL (val), 0,
 590                          VALUE_ADDRESS (val), stream, format, 1, 0, pretty);
 591         }
 592       /* Otherwise, we end up at the return outside this "if" */
 593     }
 594
 595   return val_print (type, VALUE_CONTENTS_ALL (val),
 596                     VALUE_EMBEDDED_OFFSET (val),
 597                     VALUE_ADDRESS (val) + VALUE_OFFSET (val),
 598                     stream, format, 1, 0, pretty);
 599 }