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               if (addressprint && format != 's')
 117                 {
 118                   fprintf_filtered (stream, "0x%x ", address);
 119                 }
 120               LA_PRINT_STRING (stream, valaddr, len, 0);
 121               i = len;
 122             }
 123           else
 124             {
 125               fprintf_filtered (stream, "{");
 126               /* If this is a virtual function table, print the 0th
 127                  entry specially, and the rest of the members normally.  */
 128               if (cp_is_vtbl_ptr_type (elttype))
 129                 {
 130                   i = 1;
 131                   fprintf_filtered (stream, "%d vtable entries", len - 1);
 132                 }
 133               else
 134                 {
 135                   i = 0;
 136                 }
 137               val_print_array_elements (type, valaddr, address, stream,
 138                                         format, deref_ref, recurse, pretty, i);
 139               fprintf_filtered (stream, "}");
 140             }
 141           break;
 142         }
 143       /* Array of unspecified length: treat like pointer to first elt.  */
 144       valaddr = (char *) &address;
 145       /* FALL THROUGH */
 146
 147     case TYPE_CODE_PTR:
 148       if (format && format != 's')
 149         {
 150           print_scalar_formatted (valaddr, type, format, 0, stream);
 151           break;
 152         }
 153       if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD)
 154         {
 155           cp_print_class_method (valaddr, type, stream);
 156         }
 157       else if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_MEMBER)
 158         {
 159           cp_print_class_member (valaddr,
 160                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 161                                  stream, "&");
 162         }
 163       else
 164         {
 165           addr = unpack_pointer (type, valaddr);
 166           elttype = TYPE_TARGET_TYPE (type);
 167
 168           if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
 169             {
 170               /* Try to print what function it points to.  */
 171               print_address_demangle (addr, stream, demangle);
 172               /* Return value is irrelevant except for string pointers.  */
 173               return (0);
 174             }
 175
 176           if (addressprint && format != 's')
 177             {
 178               fprintf_filtered (stream, "0x%x", addr);
 179             }
 180
 181           /* For a pointer to char or unsigned char, also print the string
 182              pointed to, unless pointer is null.  */
 183           if (TYPE_LENGTH (elttype) == 1
 184               && TYPE_CODE (elttype) == TYPE_CODE_INT
 185               && (format == 0 || format == 's')
 186               && addr != 0)
 187             {
 188               i = val_print_string (addr, 0, stream);
 189             }
 190           else if (cp_is_vtbl_member(type))
 191             {
 192               /* print vtbl's nicely */
 193               CORE_ADDR vt_address = unpack_pointer (type, valaddr);
 194
 195               struct minimal_symbol *msymbol =
 196                 lookup_minimal_symbol_by_pc (vt_address);
 197               if ((msymbol != NULL) &&
 198                   (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
 199                 {
 200                   fputs_filtered (" <", stream);
 201                   fputs_filtered (SYMBOL_SOURCE_NAME (msymbol), stream);
 202                   fputs_filtered (">", stream);
 203                 }
 204               if (vtblprint)
 205                 {
 206                   value vt_val;
 207
 208                   vt_val = value_at (TYPE_TARGET_TYPE (type), vt_address);
 209                   val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val),
 210                              VALUE_ADDRESS (vt_val), stream, format,
 211                              deref_ref, recurse + 1, pretty);
 212                   if (pretty)
 213                     {
 214                       fprintf_filtered (stream, "\n");
 215                       print_spaces_filtered (2 + 2 * recurse, stream);
 216                     }
 217                 }
 218               }
 219
 220           /* Return number of characters printed, plus one for the
 221              terminating null if we have "reached the end".  */
 222           return (i + (print_max && i != print_max));
 223         }
 224       break;
 225
 226     case TYPE_CODE_MEMBER:
 227       error ("not implemented: member type in c_val_print");
 228       break;
 229
 230     case TYPE_CODE_REF:
 231       if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_MEMBER)
 232         {
 233           cp_print_class_member (valaddr,
 234                                  TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
 235                                  stream, "");
 236           break;
 237         }
 238       if (addressprint)
 239         {
 240           fprintf_filtered (stream, "@0x%lx",
 241                             unpack_long (builtin_type_int, valaddr));
 242           if (deref_ref)
 243             fputs_filtered (": ", stream);
 244         }
 245       /* De-reference the reference.  */
 246       if (deref_ref)
 247         {
 248           if (TYPE_CODE (TYPE_TARGET_TYPE (type)) != TYPE_CODE_UNDEF)
 249             {
 250               value deref_val =
 251                 value_at
 252                   (TYPE_TARGET_TYPE (type),
 253                    unpack_pointer (lookup_pointer_type (builtin_type_void),
 254                                    valaddr));
 255               val_print (VALUE_TYPE (deref_val),
 256                          VALUE_CONTENTS (deref_val),
 257                          VALUE_ADDRESS (deref_val), stream, format,
 258                          deref_ref, recurse + 1, pretty);
 259             }
 260           else
 261             fputs_filtered ("???", stream);
 262         }
 263       break;
 264
 265     case TYPE_CODE_UNION:
 266       if (recurse && !unionprint)
 267         {
 268           fprintf_filtered (stream, "{...}");
 269           break;
 270         }
 271       /* Fall through.  */
 272     case TYPE_CODE_STRUCT:
 273       if (vtblprint && cp_is_vtbl_ptr_type(type))
 274         {
 275           /* Print the unmangled name if desired.  */
 276           print_address_demangle(*((int *) (valaddr +   /* FIXME bytesex */
 277               TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8)),
 278               stream, demangle);
 279           break;
 280         }
 281       cp_print_value_fields (type, valaddr, stream, format, recurse, pretty,
 282                              0);
 283       break;
 284
 285     case TYPE_CODE_ENUM:
 286       if (format)
 287         {
 288           print_scalar_formatted (valaddr, type, format, 0, stream);
 289           break;
 290         }
 291       len = TYPE_NFIELDS (type);
 292       val = unpack_long (builtin_type_int, valaddr);
 293       for (i = 0; i < len; i++)
 294         {
 295           QUIT;
 296           if (val == TYPE_FIELD_BITPOS (type, i))
 297             {
 298               break;
 299             }
 300         }
 301       if (i < len)
 302         {
 303           fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
 304         }
 305       else
 306         {
 307 #ifdef LONG_LONG
 308           fprintf_filtered (stream, "%lld", val);
 309 #else
 310           fprintf_filtered (stream, "%ld", val);
 311 #endif
 312         }
 313       break;
 314
 315     case TYPE_CODE_FUNC:
 316       if (format)
 317         {
 318           print_scalar_formatted (valaddr, type, format, 0, stream);
 319           break;
 320         }
 321       /* FIXME, we should consider, at least for ANSI C language, eliminating
 322          the distinction made between FUNCs and POINTERs to FUNCs.  */
 323       fprintf_filtered (stream, "{");
 324       type_print (type, "", stream, -1);
 325       fprintf_filtered (stream, "} ");
 326       /* Try to print what function it points to, and its address.  */
 327       print_address_demangle (address, stream, demangle);
 328       break;
 329
 330     case TYPE_CODE_INT:
 331       format = format ? format : output_format;
 332       if (format)
 333         {
 334           print_scalar_formatted (valaddr, type, format, 0, stream);
 335         }
 336       else
 337         {
 338           val_print_type_code_int (type, valaddr, stream);
 339           /* C and C++ has no single byte int type, char is used instead.
 340              Since we don't know whether the value is really intended to
 341              be used as an integer or a character, print the character
 342              equivalent as well. */
 343           if (TYPE_LENGTH (type) == 1)
 344             {
 345               fputs_filtered (" ", stream);
 346               LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr),
 347                              stream);
 348             }
 349         }
 350       break;
 351
 352     case TYPE_CODE_CHAR:
 353       format = format ? format : output_format;
 354       if (format)
 355         {
 356           print_scalar_formatted (valaddr, type, format, 0, stream);
 357         }
 358       else
 359         {
 360           fprintf_filtered (stream, TYPE_UNSIGNED (type) ? "%u" : "%d",
 361                             unpack_long (type, valaddr));
 362           fputs_filtered (" ", stream);
 363           LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr), stream);
 364         }
 365       break;
 366
 367     case TYPE_CODE_FLT:
 368       if (format)
 369         {
 370           print_scalar_formatted (valaddr, type, format, 0, stream);
 371         }
 372       else
 373         {
 374           print_floating (valaddr, type, stream);
 375         }
 376       break;
 377
 378     case TYPE_CODE_VOID:
 379       fprintf_filtered (stream, "void");
 380       break;
 381
 382     case TYPE_CODE_ERROR:
 383       fprintf_filtered (stream, "<error type>");
 384       break;
 385
 386     case TYPE_CODE_RANGE:
 387       /* FIXME, we should not ever have to print one of these yet.  */
 388       fprintf_filtered (stream, "<range type>");
 389       break;
 390
 391     case TYPE_CODE_UNDEF:
 392       /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
 393          dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
 394          and no complete type for struct foo in that file.  */
 395       fprintf_filtered (stream, "<incomplete type>");
 396       break;
 397
 398     default:
 399       error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
 400     }
 401   fflush (stream);
 402   return (0);
 403 }