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