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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 #include "c-lang.h"
  30
  31 \f
  32 /* Print data of type TYPE located at VALADDR (within GDB), which came from
  33    the inferior at address ADDRESS, onto stdio stream STREAM according to
  34    FORMAT (a letter or 0 for natural format).  The data at VALADDR is in
  35    target byte order.
  36
  37    If the data are a string pointer, returns the number of string characters
  38    printed.
  39
  40    If DEREF_REF is nonzero, then dereference references, otherwise just print
  41    them like pointers.
  42
  43    The PRETTY parameter controls prettyprinting.  */
  44
  45 int
  46 c_val_print (type, valaddr, address, stream, format, deref_ref, recurse,
  47              pretty)
  48      struct type *type;
  49      char *valaddr;
  50      CORE_ADDR address;
  51      GDB_FILE *stream;
  52      int format;
  53      int deref_ref;
  54      int recurse;
  55      enum val_prettyprint pretty;
  56 {
  57   register unsigned int i = 0;          /* Number of characters printed */
  58   unsigned len;
  59   struct type *elttype;
  60   unsigned eltlen;
  61   LONGEST val;
  62   CORE_ADDR addr;
  63
  64   CHECK_TYPEDEF (type);
  65   switch (TYPE_CODE (type))
  66     {
  67     case TYPE_CODE_ARRAY:
  68       if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
  69         {
  70           elttype = check_typedef (TYPE_TARGET_TYPE (type));
  71           eltlen = TYPE_LENGTH (elttype);
  72           len = TYPE_LENGTH (type) / eltlen;
  73           if (prettyprint_arrays)
  74             {
  75               print_spaces_filtered (2 + 2 * recurse, stream);
  76             }
  77           /* For an array of chars, print with string syntax.  */
  78           if (eltlen == 1 &&
  79               ((TYPE_CODE (elttype) == TYPE_CODE_INT)
  80                || ((current_language->la_language == language_m2)
  81                    && (TYPE_CODE (elttype) == TYPE_CODE_CHAR)))
  82               && (format == 0 || format == 's'))
  83             {
  84               /* If requested, look for the first null char and only print
  85                  elements up to it.  */
  86               if (stop_print_at_null)
  87                 {
  88                   int temp_len;
  89
  90                   /* Look for a NULL char. */
  91                   for (temp_len = 0;
  92                        valaddr[temp_len]
  93                        && temp_len < len && temp_len < print_max;
  94                        temp_len++);
  95                   len = temp_len;
  96                 }
  97
  98               LA_PRINT_STRING (stream, valaddr, len, 0);
  99               i = len;
 100             }
 101           else
 102             {
 103               fprintf_filtered (stream, "{");
 104               /* If this is a virtual function table, print the 0th
 105                  entry specially, and the rest of the members normally.  */
 106               if (cp_is_vtbl_ptr_type (elttype))
 107                 {
 108                   i = 1;
 109                   fprintf_filtered (stream, "%d vtable entries", len - 1);
 110                 }
 111               else
 112                 {
 113                   i = 0;
 114                 }
 115               val_print_array_elements (type, valaddr, address, stream,
 116                                         format, deref_ref, recurse, pretty, i);
 117               fprintf_filtered (stream, "}");
 118             }
 119           break;
 120         }
 121       /* Array of unspecified length: treat like pointer to first elt.  */
 122       addr = address;
 123       goto print_unpacked_pointer;
 124
 125     case TYPE_CODE_PTR:
 126       if (format && format != 's')
 127         {
 128           print_scalar_formatted (valaddr, type, format, 0, stream);
 129           break;
 130         }
 131       if (vtblprint && cp_is_vtbl_ptr_type(type))
 132         {
 133           /* Print the unmangled name if desired.  */
 134           /* Print vtable entry - we only get here if we ARE using
 135              -fvtable_thunks.  (Otherwise, look under TYPE_CODE_STRUCT.) */
 136           print_address_demangle(extract_address (valaddr, TYPE_LENGTH (type)),
 137                                  stream, demangle);
 138           break;
 139         }
 140       elttype = check_typedef (TYPE_TARGET_TYPE (type));
 141       if (TYPE_CODE (elttype) == TYPE_CODE_METHOD)
 142         {
 143           cp_print_class_method (valaddr, type, stream);
 144         }
 145       else if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
 146         {
 147           cp_print_class_member (valaddr,
 148                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 149                                  stream, "&");
 150         }
 151       else
 152         {
 153           addr = unpack_pointer (type, valaddr);
 154         print_unpacked_pointer:
 155
 156           if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
 157             {
 158               /* Try to print what function it points to.  */
 159               print_address_demangle (addr, stream, demangle);
 160               /* Return value is irrelevant except for string pointers.  */
 161               return (0);
 162             }
 163
 164           if (addressprint && format != 's')
 165             {
 166               print_address_numeric (addr, 1, stream);
 167             }
 168
 169           /* For a pointer to char or unsigned char, also print the string
 170              pointed to, unless pointer is null.  */
 171           if (TYPE_LENGTH (elttype) == 1
 172               && TYPE_CODE (elttype) == TYPE_CODE_INT
 173               && (format == 0 || format == 's')
 174               && addr != 0)
 175             {
 176               i = val_print_string (addr, 0, stream);
 177             }
 178           else if (cp_is_vtbl_member(type))
 179             {
 180               /* print vtbl's nicely */
 181               CORE_ADDR vt_address = unpack_pointer (type, valaddr);
 182
 183               struct minimal_symbol *msymbol =
 184                 lookup_minimal_symbol_by_pc (vt_address);
 185               if ((msymbol != NULL) &&
 186                   (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
 187                 {
 188                   fputs_filtered (" <", stream);
 189                   fputs_filtered (SYMBOL_SOURCE_NAME (msymbol), stream);
 190                   fputs_filtered (">", stream);
 191                 }
 192               if (vt_address && vtblprint)
 193                 {
 194                   value_ptr vt_val;
 195                   struct symbol *wsym = (struct symbol *)NULL;
 196                   struct type *wtype;
 197                   struct symtab *s;
 198                   struct block *block = (struct block *)NULL;
 199                   int is_this_fld;
 200
 201                   if (msymbol != NULL)
 202                     wsym = lookup_symbol (SYMBOL_NAME(msymbol), block,
 203                                 VAR_NAMESPACE, &is_this_fld, &s);
 204
 205                   if (wsym)
 206                     {
 207                       wtype = SYMBOL_TYPE(wsym);
 208                     }
 209                   else
 210                     {
 211                       wtype = TYPE_TARGET_TYPE(type);
 212                     }
 213                   vt_val = value_at (wtype, vt_address);
 214                   val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val),
 215                              VALUE_ADDRESS (vt_val), stream, format,
 216                              deref_ref, recurse + 1, pretty);
 217                   if (pretty)
 218                     {
 219                       fprintf_filtered (stream, "\n");
 220                       print_spaces_filtered (2 + 2 * recurse, stream);
 221                     }
 222                 }
 223               }
 224
 225           /* Return number of characters printed, including the terminating
 226              '\0' if we reached the end.  val_print_string takes care including
 227              the terminating '\0' if necessary.  */
 228           return i;
 229         }
 230       break;
 231
 232     case TYPE_CODE_MEMBER:
 233       error ("not implemented: member type in c_val_print");
 234       break;
 235
 236     case TYPE_CODE_REF:
 237       elttype = check_typedef (TYPE_TARGET_TYPE (type));
 238       if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
 239         {
 240           cp_print_class_member (valaddr,
 241                                  TYPE_DOMAIN_TYPE (elttype),
 242                                  stream, "");
 243           break;
 244         }
 245       if (addressprint)
 246         {
 247           fprintf_filtered (stream, "@");
 248           print_address_numeric
 249             (extract_address (valaddr,
 250                               TARGET_PTR_BIT / HOST_CHAR_BIT), 1, stream);
 251           if (deref_ref)
 252             fputs_filtered (": ", stream);
 253         }
 254       /* De-reference the reference.  */
 255       if (deref_ref)
 256         {
 257           if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
 258             {
 259               value_ptr deref_val =
 260                 value_at
 261                   (TYPE_TARGET_TYPE (type),
 262                    unpack_pointer (lookup_pointer_type (builtin_type_void),
 263                                    valaddr));
 264               val_print (VALUE_TYPE (deref_val),
 265                          VALUE_CONTENTS (deref_val),
 266                          VALUE_ADDRESS (deref_val), stream, format,
 267                          deref_ref, recurse + 1, pretty);
 268             }
 269           else
 270             fputs_filtered ("???", stream);
 271         }
 272       break;
 273
 274     case TYPE_CODE_UNION:
 275       if (recurse && !unionprint)
 276         {
 277           fprintf_filtered (stream, "{...}");
 278           break;
 279         }
 280       /* Fall through.  */
 281     case TYPE_CODE_STRUCT:
 282       if (vtblprint && cp_is_vtbl_ptr_type(type))
 283         {
 284           /* Print the unmangled name if desired.  */
 285           /* Print vtable entry - we only get here if NOT using
 286              -fvtable_thunks.  (Otherwise, look under TYPE_CODE_PTR.) */
 287           print_address_demangle(*((int *) (valaddr +   /* FIXME bytesex */
 288               TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8)),
 289               stream, demangle);
 290         }
 291       else
 292         cp_print_value_fields (type, valaddr, address, stream, format,
 293                                recurse, pretty, NULL, 0);
 294       break;
 295
 296     case TYPE_CODE_ENUM:
 297       if (format)
 298         {
 299           print_scalar_formatted (valaddr, type, format, 0, stream);
 300           break;
 301         }
 302       len = TYPE_NFIELDS (type);
 303       val = unpack_long (type, valaddr);
 304       for (i = 0; i < len; i++)
 305         {
 306           QUIT;
 307           if (val == TYPE_FIELD_BITPOS (type, i))
 308             {
 309               break;
 310             }
 311         }
 312       if (i < len)
 313         {
 314           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 315         }
 316       else
 317         {
 318           print_longest (stream, 'd', 0, val);
 319         }
 320       break;
 321
 322     case TYPE_CODE_FUNC:
 323       if (format)
 324         {
 325           print_scalar_formatted (valaddr, type, format, 0, stream);
 326           break;
 327         }
 328       /* FIXME, we should consider, at least for ANSI C language, eliminating
 329          the distinction made between FUNCs and POINTERs to FUNCs.  */
 330       fprintf_filtered (stream, "{");
 331       type_print (type, "", stream, -1);
 332       fprintf_filtered (stream, "} ");
 333       /* Try to print what function it points to, and its address.  */
 334       print_address_demangle (address, stream, demangle);
 335       break;
 336
 337     case TYPE_CODE_BOOL:
 338       format = format ? format : output_format;
 339       if (format)
 340         print_scalar_formatted (valaddr, type, format, 0, stream);
 341       else
 342         {
 343           val = unpack_long (type, valaddr);
 344           if (val == 0)
 345             fputs_filtered ("false", stream);
 346           else if (val == 1)
 347             fputs_filtered ("true", stream);
 348           else
 349             print_longest (stream, 'd', 0, val);
 350         }
 351       break;
 352
 353     case TYPE_CODE_RANGE:
 354       /* FIXME: create_range_type does not set the unsigned bit in a
 355          range type (I think it probably should copy it from the target
 356          type), so we won't print values which are too large to
 357          fit in a signed integer correctly.  */
 358       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
 359          print with the target type, though, because the size of our type
 360          and the target type might differ).  */
 361       /* FALLTHROUGH */
 362
 363     case TYPE_CODE_INT:
 364       format = format ? format : output_format;
 365       if (format)
 366         {
 367           print_scalar_formatted (valaddr, type, format, 0, stream);
 368         }
 369       else
 370         {
 371           val_print_type_code_int (type, valaddr, stream);
 372           /* C and C++ has no single byte int type, char is used instead.
 373              Since we don't know whether the value is really intended to
 374              be used as an integer or a character, print the character
 375              equivalent as well. */
 376           if (TYPE_LENGTH (type) == 1)
 377             {
 378               fputs_filtered (" ", stream);
 379               LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr),
 380                              stream);
 381             }
 382         }
 383       break;
 384
 385     case TYPE_CODE_CHAR:
 386       format = format ? format : output_format;
 387       if (format)
 388         {
 389           print_scalar_formatted (valaddr, type, format, 0, stream);
 390         }
 391       else
 392         {
 393           fprintf_filtered (stream, TYPE_UNSIGNED (type) ? "%u" : "%d",
 394                             unpack_long (type, valaddr));
 395           fputs_filtered (" ", stream);
 396           LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr), stream);
 397         }
 398       break;
 399
 400     case TYPE_CODE_FLT:
 401       if (format)
 402         {
 403           print_scalar_formatted (valaddr, type, format, 0, stream);
 404         }
 405       else
 406         {
 407           print_floating (valaddr, type, stream);
 408         }
 409       break;
 410
 411     case TYPE_CODE_VOID:
 412       fprintf_filtered (stream, "void");
 413       break;
 414
 415     case TYPE_CODE_ERROR:
 416       fprintf_filtered (stream, "<error type>");
 417       break;
 418
 419     case TYPE_CODE_UNDEF:
 420       /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
 421          dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
 422          and no complete type for struct foo in that file.  */
 423       fprintf_filtered (stream, "<incomplete type>");
 424       break;
 425
 426     default:
 427       error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
 428     }
 429   gdb_flush (stream);
 430   return (0);
 431 }
 432 \f
 433 int
 434 c_value_print (val, stream, format, pretty)
 435      value_ptr val;
 436      GDB_FILE *stream;
 437      int format;
 438      enum val_prettyprint pretty;
 439 {
 440   struct type *type = VALUE_TYPE (val);
 441
 442   /* If it is a pointer, indicate what it points to.
 443
 444      Print type also if it is a reference.
 445
 446      C++: if it is a member pointer, we will take care
 447      of that when we print it.  */
 448   if (TYPE_CODE (type) == TYPE_CODE_PTR ||
 449       TYPE_CODE (type) == TYPE_CODE_REF)
 450     {
 451       /* Hack:  remove (char *) for char strings.  Their
 452          type is indicated by the quoted string anyway. */
 453       if (TYPE_CODE (type) == TYPE_CODE_PTR &&
 454           TYPE_NAME (type) == NULL &&
 455           TYPE_NAME (TYPE_TARGET_TYPE (type)) != NULL &&
 456           STREQ (TYPE_NAME (TYPE_TARGET_TYPE (type)), "char"))
 457         {
 458           /* Print nothing */
 459         }
 460       else
 461         {
 462           fprintf_filtered (stream, "(");
 463           type_print (type, "", stream, -1);
 464           fprintf_filtered (stream, ") ");
 465         }
 466     }
 467   return (val_print (type, VALUE_CONTENTS (val),
 468                      VALUE_ADDRESS (val), stream, format, 1, 0, pretty));
 469 }