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