gdb/c-valprint.c

   1 /* Support for printing C values for GDB, the GNU debugger.
   2    Copyright 1986, 1988, 1989, 1991, 1992, 1993, 1994
   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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 #include "defs.h"
  22 #include "symtab.h"
  23 #include "gdbtypes.h"
  24 #include "expression.h"
  25 #include "value.h"
  26 #include "demangle.h"
  27 #include "valprint.h"
  28 #include "language.h"
  29
  30 /* BEGIN-FIXME */
  31
  32 extern int vtblprint;           /* Controls printing of vtbl's */
  33
  34 extern void
  35 cp_print_class_member PARAMS ((char *, struct type *, GDB_FILE *, char *));
  36
  37 extern void
  38 cp_print_class_method PARAMS ((char *, struct type *, GDB_FILE *));
  39
  40 extern void
  41 cp_print_value_fields PARAMS ((struct type *, char *, GDB_FILE *, int, int,
  42                                enum val_prettyprint, struct type **));
  43
  44 extern int
  45 cp_is_vtbl_ptr_type PARAMS ((struct type *));
  46
  47 extern int
  48 cp_is_vtbl_member PARAMS ((struct type *));
  49
  50 /* END-FIXME */
  51
  52
  53 /* BEGIN-FIXME:  Hooks into c-typeprint.c */
  54
  55 extern void
  56 c_type_print_varspec_prefix PARAMS ((struct type *, GDB_FILE *, int, int));
  57
  58 extern void
  59 cp_type_print_method_args PARAMS ((struct type **, char *, char *, int,
  60                                    GDB_FILE *));
  61 /* END-FIXME */
  62
  63
  64 extern struct obstack dont_print_obstack;
  65
  66 \f
  67 /* Print data of type TYPE located at VALADDR (within GDB), which came from
  68    the inferior at address ADDRESS, onto stdio stream STREAM according to
  69    FORMAT (a letter or 0 for natural format).  The data at VALADDR is in
  70    target byte order.
  71
  72    If the data are a string pointer, returns the number of string characters
  73    printed.
  74
  75    If DEREF_REF is nonzero, then dereference references, otherwise just print
  76    them like pointers.
  77
  78    The PRETTY parameter controls prettyprinting.  */
  79
  80 int
  81 c_val_print (type, valaddr, address, stream, format, deref_ref, recurse,
  82              pretty)
  83      struct type *type;
  84      char *valaddr;
  85      CORE_ADDR address;
  86      GDB_FILE *stream;
  87      int format;
  88      int deref_ref;
  89      int recurse;
  90      enum val_prettyprint pretty;
  91 {
  92   register unsigned int i = 0;          /* Number of characters printed */
  93   unsigned len;
  94   struct type *elttype;
  95   unsigned eltlen;
  96   LONGEST val;
  97   CORE_ADDR addr;
  98
  99   switch (TYPE_CODE (type))
 100     {
 101     case TYPE_CODE_ARRAY:
 102       if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
 103         {
 104           elttype = TYPE_TARGET_TYPE (type);
 105           eltlen = TYPE_LENGTH (elttype);
 106           len = TYPE_LENGTH (type) / eltlen;
 107           if (prettyprint_arrays)
 108             {
 109               print_spaces_filtered (2 + 2 * recurse, stream);
 110             }
 111           /* For an array of chars, print with string syntax.  */
 112           if (eltlen == 1 && TYPE_CODE (elttype) == TYPE_CODE_INT
 113               && (format == 0 || format == 's'))
 114             {
 115               LA_PRINT_STRING (stream, valaddr, len, 0);
 116               i = len;
 117             }
 118           else
 119             {
 120               fprintf_filtered (stream, "{");
 121               /* If this is a virtual function table, print the 0th
 122                  entry specially, and the rest of the members normally.  */
 123               if (cp_is_vtbl_ptr_type (elttype))
 124                 {
 125                   i = 1;
 126                   fprintf_filtered (stream, "%d vtable entries", len - 1);
 127                 }
 128               else
 129                 {
 130                   i = 0;
 131                 }
 132               val_print_array_elements (type, valaddr, address, stream,
 133                                         format, deref_ref, recurse, pretty, i);
 134               fprintf_filtered (stream, "}");
 135             }
 136           break;
 137         }
 138       /* Array of unspecified length: treat like pointer to first elt.  */
 139       addr = address;
 140       goto print_unpacked_pointer;
 141
 142     case TYPE_CODE_PTR:
 143       if (format && format != 's')
 144         {
 145           print_scalar_formatted (valaddr, type, format, 0, stream);
 146           break;
 147         }
 148       if (vtblprint && cp_is_vtbl_ptr_type(type))
 149         {
 150           /* Print the unmangled name if desired.  */
 151           /* Print vtable entry - we only get here if we ARE using
 152              -fvtable_thunks.  (Otherwise, look under TYPE_CODE_STRUCT.) */
 153           print_address_demangle(extract_address (valaddr, TYPE_LENGTH (type)),
 154                                  stream, demangle);
 155           break;
 156         }
 157       if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD)
 158         {
 159           cp_print_class_method (valaddr, type, stream);
 160         }
 161       else if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_MEMBER)
 162         {
 163           cp_print_class_member (valaddr,
 164                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 165                                  stream, "&");
 166         }
 167       else
 168         {
 169           addr = unpack_pointer (type, valaddr);
 170         print_unpacked_pointer:
 171           elttype = TYPE_TARGET_TYPE (type);
 172
 173           if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
 174             {
 175               /* Try to print what function it points to.  */
 176               print_address_demangle (addr, stream, demangle);
 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           if (TYPE_LENGTH (elttype) == 1
 189               && TYPE_CODE (elttype) == TYPE_CODE_INT
 190               && (format == 0 || format == 's')
 191               && addr != 0)
 192             {
 193               i = val_print_string (addr, 0, stream);
 194             }
 195           else if (cp_is_vtbl_member(type))
 196             {
 197               /* print vtbl's nicely */
 198               CORE_ADDR vt_address = unpack_pointer (type, valaddr);
 199
 200               struct minimal_symbol *msymbol =
 201                 lookup_minimal_symbol_by_pc (vt_address);
 202               if ((msymbol != NULL) &&
 203                   (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
 204                 {
 205                   fputs_filtered (" <", stream);
 206                   fputs_filtered (SYMBOL_SOURCE_NAME (msymbol), stream);
 207                   fputs_filtered (">", stream);
 208                 }
 209               if (vt_address && vtblprint)
 210                 {
 211                   value_ptr vt_val;
 212                   struct symbol *wsym = (struct symbol *)NULL;
 213                   struct type *wtype;
 214                   struct symtab *s;
 215                   struct block *block = (struct block *)NULL;
 216                   int is_this_fld;
 217
 218                   if (msymbol != NULL)
 219                     wsym = lookup_symbol (SYMBOL_NAME(msymbol), block,
 220                                 VAR_NAMESPACE, &is_this_fld, &s);
 221
 222                   if (wsym)
 223                     {
 224                       wtype = SYMBOL_TYPE(wsym);
 225                     }
 226                   else
 227                     {
 228                       wtype = TYPE_TARGET_TYPE(type);
 229                     }
 230                   vt_val = value_at (wtype, vt_address);
 231                   val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val),
 232                              VALUE_ADDRESS (vt_val), stream, format,
 233                              deref_ref, recurse + 1, pretty);
 234                   if (pretty)
 235                     {
 236                       fprintf_filtered (stream, "\n");
 237                       print_spaces_filtered (2 + 2 * recurse, stream);
 238                     }
 239                 }
 240               }
 241
 242           /* Return number of characters printed, including the terminating
 243              '\0' if we reached the end.  val_print_string takes care including
 244              the terminating '\0' if necessary.  */
 245           return i;
 246         }
 247       break;
 248
 249     case TYPE_CODE_MEMBER:
 250       error ("not implemented: member type in c_val_print");
 251       break;
 252
 253     case TYPE_CODE_REF:
 254       if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_MEMBER)
 255         {
 256           cp_print_class_member (valaddr,
 257                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 258                                  stream, "");
 259           break;
 260         }
 261       if (addressprint)
 262         {
 263           fprintf_filtered (stream, "@");
 264           print_address_numeric
 265             (extract_address (valaddr,
 266                               TARGET_PTR_BIT / HOST_CHAR_BIT), 1, stream);
 267           if (deref_ref)
 268             fputs_filtered (": ", stream);
 269         }
 270       /* De-reference the reference.  */
 271       if (deref_ref)
 272         {
 273           if (TYPE_CODE (TYPE_TARGET_TYPE (type)) != TYPE_CODE_UNDEF)
 274             {
 275               value_ptr deref_val =
 276                 value_at
 277                   (TYPE_TARGET_TYPE (type),
 278                    unpack_pointer (lookup_pointer_type (builtin_type_void),
 279                                    valaddr));
 280               val_print (VALUE_TYPE (deref_val),
 281                          VALUE_CONTENTS (deref_val),
 282                          VALUE_ADDRESS (deref_val), stream, format,
 283                          deref_ref, recurse + 1, pretty);
 284             }
 285           else
 286             fputs_filtered ("???", stream);
 287         }
 288       break;
 289
 290     case TYPE_CODE_UNION:
 291       if (recurse && !unionprint)
 292         {
 293           fprintf_filtered (stream, "{...}");
 294           break;
 295         }
 296       /* Fall through.  */
 297     case TYPE_CODE_STRUCT:
 298       if (vtblprint && cp_is_vtbl_ptr_type(type))
 299         {
 300           /* Print the unmangled name if desired.  */
 301           /* Print vtable entry - we only get here if NOT using
 302              -fvtable_thunks.  (Otherwise, look under TYPE_CODE_PTR.) */
 303           print_address_demangle(*((int *) (valaddr +   /* FIXME bytesex */
 304               TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8)),
 305               stream, demangle);
 306           break;
 307         }
 308       cp_print_value_fields (type, valaddr, stream, format, recurse, pretty,
 309                              0);
 310       break;
 311
 312     case TYPE_CODE_ENUM:
 313       if (format)
 314         {
 315           print_scalar_formatted (valaddr, type, format, 0, stream);
 316           break;
 317         }
 318       len = TYPE_NFIELDS (type);
 319       val = unpack_long (type, valaddr);
 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, 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       /* Do something at least vaguely reasonable, for example if the
 355          language is set wrong.  */
 356
 357     case TYPE_CODE_RANGE:
 358       /* FIXME: create_range_type does not set the unsigned bit in a
 359          range type (I think it probably should copy it from the target
 360          type), so we won't print values which are too large to
 361          fit in a signed integer correctly.  */
 362       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
 363          print with the target type, though, because the size of our type
 364          and the target type might differ).  */
 365       /* FALLTHROUGH */
 366
 367     case TYPE_CODE_INT:
 368       format = format ? format : output_format;
 369       if (format)
 370         {
 371           print_scalar_formatted (valaddr, type, format, 0, stream);
 372         }
 373       else
 374         {
 375           val_print_type_code_int (type, valaddr, stream);
 376           /* C and C++ has no single byte int type, char is used instead.
 377              Since we don't know whether the value is really intended to
 378              be used as an integer or a character, print the character
 379              equivalent as well. */
 380           if (TYPE_LENGTH (type) == 1)
 381             {
 382               fputs_filtered (" ", stream);
 383               LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr),
 384                              stream);
 385             }
 386         }
 387       break;
 388
 389     case TYPE_CODE_CHAR:
 390       format = format ? format : output_format;
 391       if (format)
 392         {
 393           print_scalar_formatted (valaddr, type, format, 0, stream);
 394         }
 395       else
 396         {
 397           fprintf_filtered (stream, TYPE_UNSIGNED (type) ? "%u" : "%d",
 398                             unpack_long (type, valaddr));
 399           fputs_filtered (" ", stream);
 400           LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr), stream);
 401         }
 402       break;
 403
 404     case TYPE_CODE_FLT:
 405       if (format)
 406         {
 407           print_scalar_formatted (valaddr, type, format, 0, stream);
 408         }
 409       else
 410         {
 411           print_floating (valaddr, type, stream);
 412         }
 413       break;
 414
 415     case TYPE_CODE_VOID:
 416       fprintf_filtered (stream, "void");
 417       break;
 418
 419     case TYPE_CODE_ERROR:
 420       fprintf_filtered (stream, "<error type>");
 421       break;
 422
 423     case TYPE_CODE_UNDEF:
 424       /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
 425          dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
 426          and no complete type for struct foo in that file.  */
 427       fprintf_filtered (stream, "<incomplete type>");
 428       break;
 429
 430     default:
 431       error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
 432     }
 433   gdb_flush (stream);
 434   return (0);
 435 }
 436 \f
 437 int
 438 c_value_print (val, stream, format, pretty)
 439      value_ptr val;
 440      GDB_FILE *stream;
 441      int format;
 442      enum val_prettyprint pretty;
 443 {
 444   /* A "repeated" value really contains several values in a row.
 445      They are made by the @ operator.
 446      Print such values as if they were arrays.  */
 447
 448   if (VALUE_REPEATED (val))
 449     {
 450       register unsigned int n = VALUE_REPETITIONS (val);
 451       register unsigned int typelen = TYPE_LENGTH (VALUE_TYPE (val));
 452       fprintf_filtered (stream, "{");
 453       /* Print arrays of characters using string syntax.  */
 454       if (typelen == 1 && TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_INT
 455           && format == 0)
 456         LA_PRINT_STRING (stream, VALUE_CONTENTS (val), n, 0);
 457       else
 458         {
 459           value_print_array_elements (val, stream, format, pretty);
 460         }
 461       fprintf_filtered (stream, "}");
 462       return (n * typelen);
 463     }
 464   else
 465     {
 466       struct type *type = VALUE_TYPE (val);
 467
 468       /* If it is a pointer, indicate what it points to.
 469
 470          Print type also if it is a reference.
 471
 472          C++: if it is a member pointer, we will take care
 473          of that when we print it.  */
 474       if (TYPE_CODE (type) == TYPE_CODE_PTR ||
 475           TYPE_CODE (type) == TYPE_CODE_REF)
 476         {
 477           /* Hack:  remove (char *) for char strings.  Their
 478              type is indicated by the quoted string anyway. */
 479           if (TYPE_CODE (type) == TYPE_CODE_PTR &&
 480               TYPE_LENGTH (TYPE_TARGET_TYPE (type)) == sizeof(char) &&
 481               TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_INT &&
 482               !TYPE_UNSIGNED (TYPE_TARGET_TYPE (type)))
 483             {
 484                 /* Print nothing */
 485             }
 486           else
 487             {
 488               fprintf_filtered (stream, "(");
 489               type_print (type, "", stream, -1);
 490               fprintf_filtered (stream, ") ");
 491             }
 492         }
 493       return (val_print (type, VALUE_CONTENTS (val),
 494                          VALUE_ADDRESS (val), stream, format, 1, 0, pretty));
 495     }
 496 }