gdb/c-valprint.c

   1 /* Support for printing C values for GDB, the GNU debugger.
   2    Copyright 1986, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997
   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      GDB_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                   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           print_address_demangle (extract_address (valaddr + embedded_offset, TYPE_LENGTH (type)),
 139                                   stream, demangle);
 140           break;
 141         }
 142       elttype = check_typedef (TYPE_TARGET_TYPE (type));
 143       if (TYPE_CODE (elttype) == TYPE_CODE_METHOD)
 144         {
 145           cp_print_class_method (valaddr + embedded_offset, type, stream);
 146         }
 147       else if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
 148         {
 149           cp_print_class_member (valaddr + embedded_offset,
 150                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 151                                  stream, "&");
 152         }
 153       else
 154         {
 155           addr = unpack_pointer (type, valaddr + embedded_offset);
 156         print_unpacked_pointer:
 157           elttype = check_typedef (TYPE_TARGET_TYPE (type));
 158
 159           if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
 160             {
 161               /* Try to print what function it points to.  */
 162               print_address_demangle (addr, stream, demangle);
 163               /* Return value is irrelevant except for string pointers.  */
 164               return (0);
 165             }
 166
 167           if (addressprint && format != 's')
 168             {
 169               print_address_numeric (addr, 1, stream);
 170             }
 171
 172           /* For a pointer to char or unsigned char, also print the string
 173              pointed to, unless pointer is null.  */
 174           /* FIXME: need to handle wchar_t here... */
 175
 176           if (TYPE_LENGTH (elttype) == 1
 177               && TYPE_CODE (elttype) == TYPE_CODE_INT
 178               && (format == 0 || format == 's')
 179               && addr != 0)
 180             {
 181               i = val_print_string (addr, -1, TYPE_LENGTH (elttype), stream);
 182             }
 183           else if (cp_is_vtbl_member (type))
 184             {
 185               /* print vtbl's nicely */
 186               CORE_ADDR vt_address = unpack_pointer (type, valaddr + embedded_offset);
 187
 188               struct minimal_symbol *msymbol =
 189               lookup_minimal_symbol_by_pc (vt_address);
 190               if ((msymbol != NULL) &&
 191                   (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
 192                 {
 193                   fputs_filtered (" <", stream);
 194                   fputs_filtered (SYMBOL_SOURCE_NAME (msymbol), stream);
 195                   fputs_filtered (">", stream);
 196                 }
 197               if (vt_address && vtblprint)
 198                 {
 199                   value_ptr vt_val;
 200                   struct symbol *wsym = (struct symbol *) NULL;
 201                   struct type *wtype;
 202                   struct symtab *s;
 203                   struct block *block = (struct block *) NULL;
 204                   int is_this_fld;
 205
 206                   if (msymbol != NULL)
 207                     wsym = lookup_symbol (SYMBOL_NAME (msymbol), block,
 208                                           VAR_NAMESPACE, &is_this_fld, &s);
 209
 210                   if (wsym)
 211                     {
 212                       wtype = SYMBOL_TYPE (wsym);
 213                     }
 214                   else
 215                     {
 216                       wtype = TYPE_TARGET_TYPE (type);
 217                     }
 218                   vt_val = value_at (wtype, vt_address, NULL);
 219                   val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val), 0,
 220                              VALUE_ADDRESS (vt_val), stream, format,
 221                              deref_ref, recurse + 1, pretty);
 222                   if (pretty)
 223                     {
 224                       fprintf_filtered (stream, "\n");
 225                       print_spaces_filtered (2 + 2 * recurse, stream);
 226                     }
 227                 }
 228             }
 229
 230           /* Return number of characters printed, including the terminating
 231              '\0' if we reached the end.  val_print_string takes care including
 232              the terminating '\0' if necessary.  */
 233           return i;
 234         }
 235       break;
 236
 237     case TYPE_CODE_MEMBER:
 238       error ("not implemented: member type in c_val_print");
 239       break;
 240
 241     case TYPE_CODE_REF:
 242       elttype = check_typedef (TYPE_TARGET_TYPE (type));
 243       if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
 244         {
 245           cp_print_class_member (valaddr + embedded_offset,
 246                                  TYPE_DOMAIN_TYPE (elttype),
 247                                  stream, "");
 248           break;
 249         }
 250       if (addressprint)
 251         {
 252           fprintf_filtered (stream, "@");
 253           print_address_numeric
 254             (extract_address (valaddr + embedded_offset,
 255                               TARGET_PTR_BIT / HOST_CHAR_BIT), 1, stream);
 256           if (deref_ref)
 257             fputs_filtered (": ", stream);
 258         }
 259       /* De-reference the reference.  */
 260       if (deref_ref)
 261         {
 262           if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
 263             {
 264               value_ptr deref_val =
 265               value_at
 266               (TYPE_TARGET_TYPE (type),
 267                unpack_pointer (lookup_pointer_type (builtin_type_void),
 268                                valaddr + embedded_offset),
 269                NULL);
 270               val_print (VALUE_TYPE (deref_val),
 271                          VALUE_CONTENTS (deref_val),
 272                          0,
 273                          VALUE_ADDRESS (deref_val),
 274                          stream,
 275                          format,
 276                          deref_ref,
 277                          recurse,
 278                          pretty);
 279             }
 280           else
 281             fputs_filtered ("???", stream);
 282         }
 283       break;
 284
 285     case TYPE_CODE_UNION:
 286       if (recurse && !unionprint)
 287         {
 288           fprintf_filtered (stream, "{...}");
 289           break;
 290         }
 291       /* Fall through.  */
 292     case TYPE_CODE_STRUCT:
 293       if (vtblprint && cp_is_vtbl_ptr_type (type))
 294         {
 295           /* Print the unmangled name if desired.  */
 296           /* Print vtable entry - we only get here if NOT using
 297              -fvtable_thunks.  (Otherwise, look under TYPE_CODE_PTR.) */
 298           print_address_demangle (extract_address (
 299                                                  valaddr + embedded_offset +
 300                            TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8,
 301                   TYPE_LENGTH (TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET))),
 302                                   stream, demangle);
 303         }
 304       else
 305         cp_print_value_fields (type, type, valaddr, embedded_offset, address, stream, format,
 306                                recurse, pretty, NULL, 0);
 307       break;
 308
 309     case TYPE_CODE_ENUM:
 310       if (format)
 311         {
 312           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 313           break;
 314         }
 315       len = TYPE_NFIELDS (type);
 316       val = unpack_long (type, valaddr + embedded_offset);
 317       for (i = 0; i < len; i++)
 318         {
 319           QUIT;
 320           if (val == TYPE_FIELD_BITPOS (type, i))
 321             {
 322               break;
 323             }
 324         }
 325       if (i < len)
 326         {
 327           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 328         }
 329       else
 330         {
 331           print_longest (stream, 'd', 0, val);
 332         }
 333       break;
 334
 335     case TYPE_CODE_FUNC:
 336       if (format)
 337         {
 338           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 339           break;
 340         }
 341       /* FIXME, we should consider, at least for ANSI C language, eliminating
 342          the distinction made between FUNCs and POINTERs to FUNCs.  */
 343       fprintf_filtered (stream, "{");
 344       type_print (type, "", stream, -1);
 345       fprintf_filtered (stream, "} ");
 346       /* Try to print what function it points to, and its address.  */
 347       print_address_demangle (address, stream, demangle);
 348       break;
 349
 350     case TYPE_CODE_BOOL:
 351       format = format ? format : output_format;
 352       if (format)
 353         print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 354       else
 355         {
 356           val = unpack_long (type, valaddr + embedded_offset);
 357           if (val == 0)
 358             fputs_filtered ("false", stream);
 359           else if (val == 1)
 360             fputs_filtered ("true", stream);
 361           else
 362             print_longest (stream, 'd', 0, val);
 363         }
 364       break;
 365
 366     case TYPE_CODE_RANGE:
 367       /* FIXME: create_range_type does not set the unsigned bit in a
 368          range type (I think it probably should copy it from the target
 369          type), so we won't print values which are too large to
 370          fit in a signed integer correctly.  */
 371       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
 372          print with the target type, though, because the size of our type
 373          and the target type might differ).  */
 374       /* FALLTHROUGH */
 375
 376     case TYPE_CODE_INT:
 377       format = format ? format : output_format;
 378       if (format)
 379         {
 380           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 381         }
 382       else
 383         {
 384           val_print_type_code_int (type, valaddr + embedded_offset, stream);
 385           /* C and C++ has no single byte int type, char is used instead.
 386              Since we don't know whether the value is really intended to
 387              be used as an integer or a character, print the character
 388              equivalent as well. */
 389           if (TYPE_LENGTH (type) == 1)
 390             {
 391               fputs_filtered (" ", stream);
 392               LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr + embedded_offset),
 393                              stream);
 394             }
 395         }
 396       break;
 397
 398     case TYPE_CODE_CHAR:
 399       format = format ? format : output_format;
 400       if (format)
 401         {
 402           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 403         }
 404       else
 405         {
 406           val = unpack_long (type, valaddr + embedded_offset);
 407           if (TYPE_UNSIGNED (type))
 408             fprintf_filtered (stream, "%u", (unsigned int) val);
 409           else
 410             fprintf_filtered (stream, "%d", (int) val);
 411           fputs_filtered (" ", stream);
 412           LA_PRINT_CHAR ((unsigned char) val, stream);
 413         }
 414       break;
 415
 416     case TYPE_CODE_FLT:
 417       if (format)
 418         {
 419           print_scalar_formatted (valaddr + embedded_offset, type, format, 0, stream);
 420         }
 421       else
 422         {
 423           print_floating (valaddr + embedded_offset, type, stream);
 424         }
 425       break;
 426
 427     case TYPE_CODE_METHOD:
 428       cp_print_class_method (valaddr + embedded_offset, lookup_pointer_type (type), stream);
 429       break;
 430
 431     case TYPE_CODE_VOID:
 432       fprintf_filtered (stream, "void");
 433       break;
 434
 435     case TYPE_CODE_ERROR:
 436       fprintf_filtered (stream, "<error type>");
 437       break;
 438
 439     case TYPE_CODE_UNDEF:
 440       /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
 441          dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
 442          and no complete type for struct foo in that file.  */
 443       fprintf_filtered (stream, "<incomplete type>");
 444       break;
 445
 446     default:
 447       error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
 448     }
 449   gdb_flush (stream);
 450   return (0);
 451 }
 452 \f
 453 int
 454 c_value_print (val, stream, format, pretty)
 455      value_ptr val;
 456      GDB_FILE *stream;
 457      int format;
 458      enum val_prettyprint pretty;
 459 {
 460   struct type *type = VALUE_TYPE (val);
 461   struct type *real_type;
 462   int full, top, using_enc;
 463
 464   /* If it is a pointer, indicate what it points to.
 465
 466      Print type also if it is a reference.
 467
 468      C++: if it is a member pointer, we will take care
 469      of that when we print it.  */
 470   if (TYPE_CODE (type) == TYPE_CODE_PTR ||
 471       TYPE_CODE (type) == TYPE_CODE_REF)
 472     {
 473       /* Hack:  remove (char *) for char strings.  Their
 474          type is indicated by the quoted string anyway. */
 475       if (TYPE_CODE (type) == TYPE_CODE_PTR &&
 476           TYPE_NAME (type) == NULL &&
 477           TYPE_NAME (TYPE_TARGET_TYPE (type)) != NULL &&
 478           STREQ (TYPE_NAME (TYPE_TARGET_TYPE (type)), "char"))
 479         {
 480           /* Print nothing */
 481         }
 482       else if (objectprint && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS))
 483         {
 484           /* Pointer to class, check real type of object */
 485           fprintf_filtered (stream, "(");
 486           type = value_rtti_target_type (val, &full, &top, &using_enc);
 487           if (type)
 488             {
 489               /* RTTI entry found */
 490               type = lookup_pointer_type (type);
 491               type_print (type, "", stream, -1);
 492             }
 493           else
 494             {
 495               /* No RTTI fields, do whatever we can */
 496               type = VALUE_ENCLOSING_TYPE (val);
 497               type_print (type, "", stream, -1);
 498               fprintf_filtered (stream, " ?");
 499             }
 500           fprintf_filtered (stream, ") ");
 501         }
 502       else
 503         {
 504           /* normal case */
 505           fprintf_filtered (stream, "(");
 506           type_print (type, "", stream, -1);
 507           fprintf_filtered (stream, ") ");
 508         }
 509     }
 510   if (objectprint && (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_CLASS))
 511     {
 512       /* Attempt to determine real type of object */
 513       real_type = value_rtti_type (val, &full, &top, &using_enc);
 514       if (real_type)
 515         {
 516           /* We have RTTI information, so use it */
 517           val = value_full_object (val, real_type, full, top, using_enc);
 518           fprintf_filtered (stream, "(%s%s) ",
 519                             TYPE_NAME (real_type),
 520                             full ? "" : " [incomplete object]");
 521           /* Print out object: enclosing type is same as real_type if full */
 522           return val_print (VALUE_ENCLOSING_TYPE (val), VALUE_CONTENTS_ALL (val), 0,
 523                          VALUE_ADDRESS (val), stream, format, 1, 0, pretty);
 524         }
 525       else if (type != VALUE_ENCLOSING_TYPE (val))
 526         {
 527           /* No RTTI information, so let's do our best */
 528           fprintf_filtered (stream, "(%s ?) ",
 529                             TYPE_NAME (VALUE_ENCLOSING_TYPE (val)));
 530           return val_print (VALUE_ENCLOSING_TYPE (val), VALUE_CONTENTS_ALL (val), 0,
 531                          VALUE_ADDRESS (val), stream, format, 1, 0, pretty);
 532         }
 533       /* Otherwise, we end up at the return outside this "if" */
 534     }
 535
 536   return val_print (type, VALUE_CONTENTS_ALL (val), VALUE_EMBEDDED_OFFSET (val),
 537                     VALUE_ADDRESS (val),
 538                     stream, format, 1, 0, pretty);
 539 }