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