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 *, FILE *, char *));
  36
  37 extern void
  38 cp_print_class_method PARAMS ((char *, struct type *, FILE *));
  39
  40 extern void
  41 cp_print_value_fields PARAMS ((struct type *, char *, 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 *, FILE *, int, int));
  57
  58 extern void
  59 cp_type_print_method_args PARAMS ((struct type **, char *, char *, int,
  60                                    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      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   unsigned char c;
  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       valaddr = (char *) &address;
 141       /* FALL THROUGH */
 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           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%x", 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 (vtblprint)
 201                 {
 202                   value vt_val;
 203
 204                   vt_val = value_at (TYPE_TARGET_TYPE (type), vt_address);
 205                   val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val),
 206                              VALUE_ADDRESS (vt_val), stream, format,
 207                              deref_ref, recurse + 1, pretty);
 208                   if (pretty)
 209                     {
 210                       fprintf_filtered (stream, "\n");
 211                       print_spaces_filtered (2 + 2 * recurse, stream);
 212                     }
 213                 }
 214               }
 215
 216           /* Return number of characters printed, plus one for the
 217              terminating null if we have "reached the end".  */
 218           return (i + (print_max && i != print_max));
 219         }
 220       break;
 221
 222     case TYPE_CODE_MEMBER:
 223       error ("not implemented: member type in c_val_print");
 224       break;
 225
 226     case TYPE_CODE_REF:
 227       if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_MEMBER)
 228         {
 229           cp_print_class_member (valaddr,
 230                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 231                                  stream, "");
 232           break;
 233         }
 234       if (addressprint)
 235         {
 236           fprintf_filtered (stream, "@0x%lx",
 237                             unpack_long (builtin_type_int, valaddr));
 238           if (deref_ref)
 239             fputs_filtered (": ", stream);
 240         }
 241       /* De-reference the reference.  */
 242       if (deref_ref)
 243         {
 244           if (TYPE_CODE (TYPE_TARGET_TYPE (type)) != TYPE_CODE_UNDEF)
 245             {
 246               value deref_val =
 247                 value_at
 248                   (TYPE_TARGET_TYPE (type),
 249                    unpack_pointer (lookup_pointer_type (builtin_type_void),
 250                                    valaddr));
 251               val_print (VALUE_TYPE (deref_val),
 252                          VALUE_CONTENTS (deref_val),
 253                          VALUE_ADDRESS (deref_val), stream, format,
 254                          deref_ref, recurse + 1, pretty);
 255             }
 256           else
 257             fputs_filtered ("???", stream);
 258         }
 259       break;
 260
 261     case TYPE_CODE_UNION:
 262       if (recurse && !unionprint)
 263         {
 264           fprintf_filtered (stream, "{...}");
 265           break;
 266         }
 267       /* Fall through.  */
 268     case TYPE_CODE_STRUCT:
 269       if (vtblprint && cp_is_vtbl_ptr_type(type))
 270         {
 271           /* Print the unmangled name if desired.  */
 272           print_address_demangle(*((int *) (valaddr +   /* FIXME bytesex */
 273               TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8)),
 274               stream, demangle);
 275           break;
 276         }
 277       cp_print_value_fields (type, valaddr, stream, format, recurse, pretty,
 278                              0);
 279       break;
 280
 281     case TYPE_CODE_ENUM:
 282       if (format)
 283         {
 284           print_scalar_formatted (valaddr, type, format, 0, stream);
 285           break;
 286         }
 287       len = TYPE_NFIELDS (type);
 288       val = unpack_long (type, valaddr);
 289       for (i = 0; i < len; i++)
 290         {
 291           QUIT;
 292           if (val == TYPE_FIELD_BITPOS (type, i))
 293             {
 294               break;
 295             }
 296         }
 297       if (i < len)
 298         {
 299           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 300         }
 301       else
 302         {
 303           print_longest (stream, 'd', 0, val);
 304         }
 305       break;
 306
 307     case TYPE_CODE_FUNC:
 308       if (format)
 309         {
 310           print_scalar_formatted (valaddr, type, format, 0, stream);
 311           break;
 312         }
 313       /* FIXME, we should consider, at least for ANSI C language, eliminating
 314          the distinction made between FUNCs and POINTERs to FUNCs.  */
 315       fprintf_filtered (stream, "{");
 316       type_print (type, "", stream, -1);
 317       fprintf_filtered (stream, "} ");
 318       /* Try to print what function it points to, and its address.  */
 319       print_address_demangle (address, stream, demangle);
 320       break;
 321
 322     case TYPE_CODE_INT:
 323       format = format ? format : output_format;
 324       if (format)
 325         {
 326           print_scalar_formatted (valaddr, type, format, 0, stream);
 327         }
 328       else
 329         {
 330           val_print_type_code_int (type, valaddr, stream);
 331           /* C and C++ has no single byte int type, char is used instead.
 332              Since we don't know whether the value is really intended to
 333              be used as an integer or a character, print the character
 334              equivalent as well. */
 335           if (TYPE_LENGTH (type) == 1)
 336             {
 337               fputs_filtered (" ", stream);
 338               LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr),
 339                              stream);
 340             }
 341         }
 342       break;
 343
 344     case TYPE_CODE_CHAR:
 345       format = format ? format : output_format;
 346       if (format)
 347         {
 348           print_scalar_formatted (valaddr, type, format, 0, stream);
 349         }
 350       else
 351         {
 352           fprintf_filtered (stream, TYPE_UNSIGNED (type) ? "%u" : "%d",
 353                             unpack_long (type, valaddr));
 354           fputs_filtered (" ", stream);
 355           LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr), stream);
 356         }
 357       break;
 358
 359     case TYPE_CODE_FLT:
 360       if (format)
 361         {
 362           print_scalar_formatted (valaddr, type, format, 0, stream);
 363         }
 364       else
 365         {
 366           print_floating (valaddr, type, stream);
 367         }
 368       break;
 369
 370     case TYPE_CODE_VOID:
 371       fprintf_filtered (stream, "void");
 372       break;
 373
 374     case TYPE_CODE_ERROR:
 375       fprintf_filtered (stream, "<error type>");
 376       break;
 377
 378     case TYPE_CODE_RANGE:
 379       /* FIXME, we should not ever have to print one of these yet.  */
 380       fprintf_filtered (stream, "<range type>");
 381       break;
 382
 383     case TYPE_CODE_UNDEF:
 384       /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
 385          dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
 386          and no complete type for struct foo in that file.  */
 387       fprintf_filtered (stream, "<incomplete type>");
 388       break;
 389
 390     default:
 391       error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
 392     }
 393   fflush (stream);
 394   return (0);
 395 }