gdb/c-valprint.c

   1 /* Support for printing C values for GDB, the GNU debugger.
   2    Copyright 1986, 1988, 1989, 1991 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include "defs.h"
  21 #include "symtab.h"
  22 #include "gdbtypes.h"
  23 #include "expression.h"
  24 #include "value.h"
  25 #include "demangle.h"
  26 #include "valprint.h"
  27 #include "language.h"
  28
  29 /* BEGIN-FIXME */
  30
  31 extern int vtblprint;           /* Controls printing of vtbl's */
  32 extern int demangle;            /* whether to print C++ syms raw or src-form */
  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 (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD)
 149         {
 150           cp_print_class_method (valaddr, type, stream);
 151         }
 152       else if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_MEMBER)
 153         {
 154           cp_print_class_member (valaddr,
 155                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 156                                  stream, "&");
 157         }
 158       else
 159         {
 160           addr = unpack_pointer (type, valaddr);
 161         print_unpacked_pointer:
 162           elttype = TYPE_TARGET_TYPE (type);
 163
 164           if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
 165             {
 166               /* Try to print what function it points to.  */
 167               print_address_demangle (addr, stream, demangle);
 168               /* Return value is irrelevant except for string pointers.  */
 169               return (0);
 170             }
 171
 172           if (addressprint && format != 's')
 173             {
 174               fprintf_filtered (stream, "0x%lx", (unsigned long)addr);
 175             }
 176
 177           /* For a pointer to char or unsigned char, also print the string
 178              pointed to, unless pointer is null.  */
 179           if (TYPE_LENGTH (elttype) == 1
 180               && TYPE_CODE (elttype) == TYPE_CODE_INT
 181               && (format == 0 || format == 's')
 182               && addr != 0)
 183             {
 184               i = val_print_string (addr, 0, stream);
 185             }
 186           else if (cp_is_vtbl_member(type))
 187             {
 188               /* print vtbl's nicely */
 189               CORE_ADDR vt_address = unpack_pointer (type, valaddr);
 190
 191               struct minimal_symbol *msymbol =
 192                 lookup_minimal_symbol_by_pc (vt_address);
 193               if ((msymbol != NULL) &&
 194                   (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
 195                 {
 196                   fputs_filtered (" <", stream);
 197                   fputs_filtered (SYMBOL_SOURCE_NAME (msymbol), stream);
 198                   fputs_filtered (">", stream);
 199                 }
 200               if (vt_address && vtblprint)
 201                 {
 202                   value vt_val;
 203                   struct symbol *wsym = (struct symbol *)NULL;
 204                   struct type *wtype;
 205                   struct symtab *s;
 206                   struct block *block = (struct block *)NULL;
 207                   int is_this_fld;
 208
 209                   if (msymbol != NULL)
 210                     wsym = lookup_symbol (SYMBOL_NAME(msymbol), block,
 211                                 VAR_NAMESPACE, &is_this_fld, &s);
 212
 213                   if (wsym)
 214                     {
 215                       wtype = SYMBOL_TYPE(wsym);
 216                     }
 217                   else
 218                     {
 219                       wtype = TYPE_TARGET_TYPE(type);
 220                     }
 221                   vt_val = value_at (wtype, vt_address);
 222                   val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val),
 223                              VALUE_ADDRESS (vt_val), stream, format,
 224                              deref_ref, recurse + 1, pretty);
 225                   if (pretty)
 226                     {
 227                       fprintf_filtered (stream, "\n");
 228                       print_spaces_filtered (2 + 2 * recurse, stream);
 229                     }
 230                 }
 231               }
 232
 233           /* Return number of characters printed, plus one for the
 234              terminating null if we have "reached the end".  */
 235           return (i + (print_max && i != print_max));
 236         }
 237       break;
 238
 239     case TYPE_CODE_MEMBER:
 240       error ("not implemented: member type in c_val_print");
 241       break;
 242
 243     case TYPE_CODE_REF:
 244       if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_MEMBER)
 245         {
 246           cp_print_class_member (valaddr,
 247                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 248                                  stream, "");
 249           break;
 250         }
 251       if (addressprint)
 252         {
 253           fprintf_filtered (stream, "@0x%lx",
 254                             unpack_long (builtin_type_int, valaddr));
 255           if (deref_ref)
 256             fputs_filtered (": ", stream);
 257         }
 258       /* De-reference the reference.  */
 259       if (deref_ref)
 260         {
 261           if (TYPE_CODE (TYPE_TARGET_TYPE (type)) != TYPE_CODE_UNDEF)
 262             {
 263               value deref_val =
 264                 value_at
 265                   (TYPE_TARGET_TYPE (type),
 266                    unpack_pointer (lookup_pointer_type (builtin_type_void),
 267                                    valaddr));
 268               val_print (VALUE_TYPE (deref_val),
 269                          VALUE_CONTENTS (deref_val),
 270                          VALUE_ADDRESS (deref_val), stream, format,
 271                          deref_ref, recurse + 1, pretty);
 272             }
 273           else
 274             fputs_filtered ("???", stream);
 275         }
 276       break;
 277
 278     case TYPE_CODE_UNION:
 279       if (recurse && !unionprint)
 280         {
 281           fprintf_filtered (stream, "{...}");
 282           break;
 283         }
 284       /* Fall through.  */
 285     case TYPE_CODE_STRUCT:
 286       if (vtblprint && cp_is_vtbl_ptr_type(type))
 287         {
 288           /* Print the unmangled name if desired.  */
 289           print_address_demangle(*((int *) (valaddr +   /* FIXME bytesex */
 290               TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8)),
 291               stream, demangle);
 292           break;
 293         }
 294       cp_print_value_fields (type, valaddr, stream, format, recurse, pretty,
 295                              0);
 296       break;
 297
 298     case TYPE_CODE_ENUM:
 299       if (format)
 300         {
 301           print_scalar_formatted (valaddr, type, format, 0, stream);
 302           break;
 303         }
 304       len = TYPE_NFIELDS (type);
 305       val = unpack_long (type, valaddr);
 306       for (i = 0; i < len; i++)
 307         {
 308           QUIT;
 309           if (val == TYPE_FIELD_BITPOS (type, i))
 310             {
 311               break;
 312             }
 313         }
 314       if (i < len)
 315         {
 316           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 317         }
 318       else
 319         {
 320           print_longest (stream, 'd', 0, val);
 321         }
 322       break;
 323
 324     case TYPE_CODE_FUNC:
 325       if (format)
 326         {
 327           print_scalar_formatted (valaddr, type, format, 0, stream);
 328           break;
 329         }
 330       /* FIXME, we should consider, at least for ANSI C language, eliminating
 331          the distinction made between FUNCs and POINTERs to FUNCs.  */
 332       fprintf_filtered (stream, "{");
 333       type_print (type, "", stream, -1);
 334       fprintf_filtered (stream, "} ");
 335       /* Try to print what function it points to, and its address.  */
 336       print_address_demangle (address, stream, demangle);
 337       break;
 338
 339     case TYPE_CODE_BOOL:
 340       /* Do something at least vaguely reasonable, for example if the
 341          language is set wrong.  */
 342
 343     case TYPE_CODE_INT:
 344       format = format ? format : output_format;
 345       if (format)
 346         {
 347           print_scalar_formatted (valaddr, type, format, 0, stream);
 348         }
 349       else
 350         {
 351           val_print_type_code_int (type, valaddr, stream);
 352           /* C and C++ has no single byte int type, char is used instead.
 353              Since we don't know whether the value is really intended to
 354              be used as an integer or a character, print the character
 355              equivalent as well. */
 356           if (TYPE_LENGTH (type) == 1)
 357             {
 358               fputs_filtered (" ", stream);
 359               LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr),
 360                              stream);
 361             }
 362         }
 363       break;
 364
 365     case TYPE_CODE_CHAR:
 366       format = format ? format : output_format;
 367       if (format)
 368         {
 369           print_scalar_formatted (valaddr, type, format, 0, stream);
 370         }
 371       else
 372         {
 373           fprintf_filtered (stream, TYPE_UNSIGNED (type) ? "%u" : "%d",
 374                             unpack_long (type, valaddr));
 375           fputs_filtered (" ", stream);
 376           LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr), stream);
 377         }
 378       break;
 379
 380     case TYPE_CODE_FLT:
 381       if (format)
 382         {
 383           print_scalar_formatted (valaddr, type, format, 0, stream);
 384         }
 385       else
 386         {
 387           print_floating (valaddr, type, stream);
 388         }
 389       break;
 390
 391     case TYPE_CODE_VOID:
 392       fprintf_filtered (stream, "void");
 393       break;
 394
 395     case TYPE_CODE_ERROR:
 396       fprintf_filtered (stream, "<error type>");
 397       break;
 398
 399     case TYPE_CODE_RANGE:
 400       /* FIXME, we should not ever have to print one of these yet.  */
 401       fprintf_filtered (stream, "<range type>");
 402       break;
 403
 404     case TYPE_CODE_UNDEF:
 405       /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
 406          dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
 407          and no complete type for struct foo in that file.  */
 408       fprintf_filtered (stream, "<incomplete type>");
 409       break;
 410
 411     default:
 412       error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
 413     }
 414   gdb_flush (stream);
 415   return (0);
 416 }