gdb/m2-valprint.c

   1 /* Support for printing Modula 2 values for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2019 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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "symtab.h"
  22 #include "gdbtypes.h"
  23 #include "expression.h"
  24 #include "value.h"
  25 #include "valprint.h"
  26 #include "language.h"
  27 #include "typeprint.h"
  28 #include "c-lang.h"
  29 #include "m2-lang.h"
  30 #include "target.h"
  31
  32 static int print_unpacked_pointer (struct type *type,
  33                                    CORE_ADDR address, CORE_ADDR addr,
  34                                    const struct value_print_options *options,
  35                                    struct ui_file *stream);
  36 static void
  37 m2_print_array_contents (struct type *type, const gdb_byte *valaddr,
  38                          int embedded_offset, CORE_ADDR address,
  39                          struct ui_file *stream, int recurse,
  40                          struct value *val,
  41                          const struct value_print_options *options,
  42                          int len);
  43
  44
  45 /* get_long_set_bounds - assigns the bounds of the long set to low and
  46                          high.  */
  47
  48 int
  49 get_long_set_bounds (struct type *type, LONGEST *low, LONGEST *high)
  50 {
  51   int len, i;
  52
  53   if (TYPE_CODE (type) == TYPE_CODE_STRUCT)
  54     {
  55       len = TYPE_NFIELDS (type);
  56       i = TYPE_N_BASECLASSES (type);
  57       if (len == 0)
  58         return 0;
  59       *low = TYPE_LOW_BOUND (TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type, i)));
  60       *high = TYPE_HIGH_BOUND (TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type,
  61                                                                  len-1)));
  62       return 1;
  63     }
  64   error (_("expecting long_set"));
  65   return 0;
  66 }
  67
  68 static void
  69 m2_print_long_set (struct type *type, const gdb_byte *valaddr,
  70                    int embedded_offset, CORE_ADDR address,
  71                    struct ui_file *stream)
  72 {
  73   int empty_set        = 1;
  74   int element_seen     = 0;
  75   LONGEST previous_low = 0;
  76   LONGEST previous_high= 0;
  77   LONGEST i, low_bound, high_bound;
  78   LONGEST field_low, field_high;
  79   struct type *range;
  80   int len, field;
  81   struct type *target;
  82   int bitval;
  83
  84   type = check_typedef (type);
  85
  86   fprintf_filtered (stream, "{");
  87   len = TYPE_NFIELDS (type);
  88   if (get_long_set_bounds (type, &low_bound, &high_bound))
  89     {
  90       field = TYPE_N_BASECLASSES (type);
  91       range = TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type, field));
  92     }
  93   else
  94     {
  95       fprintf_filtered (stream, " %s }", _("<unknown bounds of set>"));
  96       return;
  97     }
  98
  99   target = TYPE_TARGET_TYPE (range);
 100
 101   if (get_discrete_bounds (range, &field_low, &field_high) >= 0)
 102     {
 103       for (i = low_bound; i <= high_bound; i++)
 104         {
 105           bitval = value_bit_index (TYPE_FIELD_TYPE (type, field),
 106                                     (TYPE_FIELD_BITPOS (type, field) / 8) +
 107                                     valaddr + embedded_offset, i);
 108           if (bitval < 0)
 109             error (_("bit test is out of range"));
 110           else if (bitval > 0)
 111             {
 112               previous_high = i;
 113               if (! element_seen)
 114                 {
 115                   if (! empty_set)
 116                     fprintf_filtered (stream, ", ");
 117                   print_type_scalar (target, i, stream);
 118                   empty_set    = 0;
 119                   element_seen = 1;
 120                   previous_low = i;
 121                 }
 122             }
 123           else
 124             {
 125               /* bit is not set */
 126               if (element_seen)
 127                 {
 128                   if (previous_low+1 < previous_high)
 129                     fprintf_filtered (stream, "..");
 130                   if (previous_low+1 < previous_high)
 131                     print_type_scalar (target, previous_high, stream);
 132                   element_seen = 0;
 133                 }
 134             }
 135           if (i == field_high)
 136             {
 137               field++;
 138               if (field == len)
 139                 break;
 140               range = TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type, field));
 141               if (get_discrete_bounds (range, &field_low, &field_high) < 0)
 142                 break;
 143               target = TYPE_TARGET_TYPE (range);
 144             }
 145         }
 146       if (element_seen)
 147         {
 148           if (previous_low+1 < previous_high)
 149             {
 150               fprintf_filtered (stream, "..");
 151               print_type_scalar (target, previous_high, stream);
 152             }
 153           element_seen = 0;
 154         }
 155       fprintf_filtered (stream, "}");
 156     }
 157 }
 158
 159 static void
 160 m2_print_unbounded_array (struct type *type, const gdb_byte *valaddr,
 161                           int embedded_offset, CORE_ADDR address,
 162                           struct ui_file *stream, int recurse,
 163                           const struct value_print_options *options)
 164 {
 165   CORE_ADDR addr;
 166   LONGEST len;
 167   struct value *val;
 168
 169   type = check_typedef (type);
 170
 171   addr = unpack_pointer (TYPE_FIELD_TYPE (type, 0),
 172                          (TYPE_FIELD_BITPOS (type, 0) / 8) +
 173                          valaddr + embedded_offset);
 174
 175   val = value_at_lazy (TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 0)),
 176                        addr);
 177   len = unpack_field_as_long (type, valaddr + embedded_offset, 1);
 178
 179   fprintf_filtered (stream, "{");
 180   m2_print_array_contents (value_type (val),
 181                            value_contents_for_printing (val),
 182                            value_embedded_offset (val), addr, stream,
 183                            recurse, val, options, len);
 184   fprintf_filtered (stream, ", HIGH = %d}", (int) len);
 185 }
 186
 187 static int
 188 print_unpacked_pointer (struct type *type,
 189                         CORE_ADDR address, CORE_ADDR addr,
 190                         const struct value_print_options *options,
 191                         struct ui_file *stream)
 192 {
 193   struct gdbarch *gdbarch = get_type_arch (type);
 194   struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
 195   int want_space = 0;
 196
 197   if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
 198     {
 199       /* Try to print what function it points to.  */
 200       print_function_pointer_address (options, gdbarch, addr, stream);
 201       /* Return value is irrelevant except for string pointers.  */
 202       return 0;
 203     }
 204
 205   if (options->addressprint && options->format != 's')
 206     {
 207       fputs_filtered (paddress (gdbarch, address), stream);
 208       want_space = 1;
 209     }
 210
 211   /* For a pointer to char or unsigned char, also print the string
 212      pointed to, unless pointer is null.  */
 213
 214   if (TYPE_LENGTH (elttype) == 1
 215       && TYPE_CODE (elttype) == TYPE_CODE_INT
 216       && (options->format == 0 || options->format == 's')
 217       && addr != 0)
 218     {
 219       if (want_space)
 220         fputs_filtered (" ", stream);
 221       return val_print_string (TYPE_TARGET_TYPE (type), NULL, addr, -1,
 222                                stream, options);
 223     }
 224
 225   return 0;
 226 }
 227
 228 static void
 229 print_variable_at_address (struct type *type,
 230                            const gdb_byte *valaddr,
 231                            struct ui_file *stream,
 232                            int recurse,
 233                            const struct value_print_options *options)
 234 {
 235   struct gdbarch *gdbarch = get_type_arch (type);
 236   CORE_ADDR addr = unpack_pointer (type, valaddr);
 237   struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
 238
 239   fprintf_filtered (stream, "[");
 240   fputs_filtered (paddress (gdbarch, addr), stream);
 241   fprintf_filtered (stream, "] : ");
 242
 243   if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
 244     {
 245       struct value *deref_val =
 246         value_at (TYPE_TARGET_TYPE (type), unpack_pointer (type, valaddr));
 247
 248       common_val_print (deref_val, stream, recurse, options, current_language);
 249     }
 250   else
 251     fputs_filtered ("???", stream);
 252 }
 253
 254
 255 /* m2_print_array_contents - prints out the contents of an
 256                              array up to a max_print values.
 257                              It prints arrays of char as a string
 258                              and all other data types as comma
 259                              separated values.  */
 260
 261 static void
 262 m2_print_array_contents (struct type *type, const gdb_byte *valaddr,
 263                          int embedded_offset, CORE_ADDR address,
 264                          struct ui_file *stream, int recurse,
 265                          struct value *val,
 266                          const struct value_print_options *options,
 267                          int len)
 268 {
 269   type = check_typedef (type);
 270
 271   if (TYPE_LENGTH (type) > 0)
 272     {
 273       if (options->prettyformat_arrays)
 274         print_spaces_filtered (2 + 2 * recurse, stream);
 275       /* For an array of chars, print with string syntax.  */
 276       if (TYPE_LENGTH (type) == 1 &&
 277           ((TYPE_CODE (type) == TYPE_CODE_INT)
 278            || ((current_language->la_language == language_m2)
 279                && (TYPE_CODE (type) == TYPE_CODE_CHAR)))
 280           && (options->format == 0 || options->format == 's'))
 281         val_print_string (type, NULL, address, len+1, stream, options);
 282       else
 283         {
 284           fprintf_filtered (stream, "{");
 285           val_print_array_elements (type, embedded_offset,
 286                                     address, stream, recurse, val,
 287                                     options, 0);
 288           fprintf_filtered (stream, "}");
 289         }
 290     }
 291 }
 292
 293 /* Decorations for Modula 2.  */
 294
 295 static const struct generic_val_print_decorations m2_decorations =
 296 {
 297   "",
 298   " + ",
 299   " * I",
 300   "TRUE",
 301   "FALSE",
 302   "void",
 303   "{",
 304   "}"
 305 };
 306
 307 /* See val_print for a description of the various parameters of this
 308    function; they are identical.  */
 309
 310 void
 311 m2_val_print (struct type *type, int embedded_offset,
 312               CORE_ADDR address, struct ui_file *stream, int recurse,
 313               struct value *original_value,
 314               const struct value_print_options *options)
 315 {
 316   unsigned len;
 317   struct type *elttype;
 318   CORE_ADDR addr;
 319   const gdb_byte *valaddr = value_contents_for_printing (original_value);
 320
 321   type = check_typedef (type);
 322   switch (TYPE_CODE (type))
 323     {
 324     case TYPE_CODE_ARRAY:
 325       if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
 326         {
 327           elttype = check_typedef (TYPE_TARGET_TYPE (type));
 328           len = TYPE_LENGTH (type) / TYPE_LENGTH (elttype);
 329           if (options->prettyformat_arrays)
 330             print_spaces_filtered (2 + 2 * recurse, stream);
 331           /* For an array of chars, print with string syntax.  */
 332           if (TYPE_LENGTH (elttype) == 1 &&
 333               ((TYPE_CODE (elttype) == TYPE_CODE_INT)
 334                || ((current_language->la_language == language_m2)
 335                    && (TYPE_CODE (elttype) == TYPE_CODE_CHAR)))
 336               && (options->format == 0 || options->format == 's'))
 337             {
 338               /* If requested, look for the first null char and only print
 339                  elements up to it.  */
 340               if (options->stop_print_at_null)
 341                 {
 342                   unsigned int temp_len;
 343
 344                   /* Look for a NULL char.  */
 345                   for (temp_len = 0;
 346                        (valaddr + embedded_offset)[temp_len]
 347                          && temp_len < len && temp_len < options->print_max;
 348                        temp_len++);
 349                   len = temp_len;
 350                 }
 351
 352               LA_PRINT_STRING (stream, TYPE_TARGET_TYPE (type),
 353                                valaddr + embedded_offset, len, NULL,
 354                                0, options);
 355             }
 356           else
 357             {
 358               fprintf_filtered (stream, "{");
 359               val_print_array_elements (type, embedded_offset,
 360                                         address, stream,
 361                                         recurse, original_value,
 362                                         options, 0);
 363               fprintf_filtered (stream, "}");
 364             }
 365           break;
 366         }
 367       /* Array of unspecified length: treat like pointer to first elt.  */
 368       print_unpacked_pointer (type, address, address, options, stream);
 369       break;
 370
 371     case TYPE_CODE_PTR:
 372       if (TYPE_CONST (type))
 373         print_variable_at_address (type, valaddr + embedded_offset,
 374                                    stream, recurse, options);
 375       else if (options->format && options->format != 's')
 376         val_print_scalar_formatted (type, embedded_offset,
 377                                     original_value, options, 0, stream);
 378       else
 379         {
 380           addr = unpack_pointer (type, valaddr + embedded_offset);
 381           print_unpacked_pointer (type, addr, address, options, stream);
 382         }
 383       break;
 384
 385     case TYPE_CODE_UNION:
 386       if (recurse && !options->unionprint)
 387         {
 388           fprintf_filtered (stream, "{...}");
 389           break;
 390         }
 391       /* Fall through.  */
 392     case TYPE_CODE_STRUCT:
 393       if (m2_is_long_set (type))
 394         m2_print_long_set (type, valaddr, embedded_offset, address,
 395                            stream);
 396       else if (m2_is_unbounded_array (type))
 397         m2_print_unbounded_array (type, valaddr, embedded_offset,
 398                                   address, stream, recurse, options);
 399       else
 400         cp_print_value_fields (type, type, embedded_offset,
 401                                address, stream, recurse, original_value,
 402                                options, NULL, 0);
 403       break;
 404
 405     case TYPE_CODE_SET:
 406       elttype = TYPE_INDEX_TYPE (type);
 407       elttype = check_typedef (elttype);
 408       if (TYPE_STUB (elttype))
 409         {
 410           fprintf_filtered (stream, _("<incomplete type>"));
 411           break;
 412         }
 413       else
 414         {
 415           struct type *range = elttype;
 416           LONGEST low_bound, high_bound;
 417           int i;
 418           int need_comma = 0;
 419
 420           fputs_filtered ("{", stream);
 421
 422           i = get_discrete_bounds (range, &low_bound, &high_bound);
 423         maybe_bad_bstring:
 424           if (i < 0)
 425             {
 426               fputs_filtered (_("<error value>"), stream);
 427               goto done;
 428             }
 429
 430           for (i = low_bound; i <= high_bound; i++)
 431             {
 432               int element = value_bit_index (type, valaddr + embedded_offset,
 433                                              i);
 434
 435               if (element < 0)
 436                 {
 437                   i = element;
 438                   goto maybe_bad_bstring;
 439                 }
 440               if (element)
 441                 {
 442                   if (need_comma)
 443                     fputs_filtered (", ", stream);
 444                   print_type_scalar (range, i, stream);
 445                   need_comma = 1;
 446
 447                   if (i + 1 <= high_bound
 448                       && value_bit_index (type, valaddr + embedded_offset,
 449                                           ++i))
 450                     {
 451                       int j = i;
 452
 453                       fputs_filtered ("..", stream);
 454                       while (i + 1 <= high_bound
 455                              && value_bit_index (type,
 456                                                  valaddr + embedded_offset,
 457                                                  ++i))
 458                         j = i;
 459                       print_type_scalar (range, j, stream);
 460                     }
 461                 }
 462             }
 463         done:
 464           fputs_filtered ("}", stream);
 465         }
 466       break;
 467
 468     case TYPE_CODE_RANGE:
 469       if (TYPE_LENGTH (type) == TYPE_LENGTH (TYPE_TARGET_TYPE (type)))
 470         {
 471           m2_val_print (TYPE_TARGET_TYPE (type), embedded_offset,
 472                         address, stream, recurse, original_value, options);
 473           break;
 474         }
 475       /* FIXME: create_static_range_type does not set the unsigned bit in a
 476          range type (I think it probably should copy it from the target
 477          type), so we won't print values which are too large to
 478          fit in a signed integer correctly.  */
 479       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
 480          print with the target type, though, because the size of our type
 481          and the target type might differ).  */
 482       /* FALLTHROUGH */
 483
 484     case TYPE_CODE_REF:
 485     case TYPE_CODE_ENUM:
 486     case TYPE_CODE_FUNC:
 487     case TYPE_CODE_INT:
 488     case TYPE_CODE_FLT:
 489     case TYPE_CODE_METHOD:
 490     case TYPE_CODE_VOID:
 491     case TYPE_CODE_ERROR:
 492     case TYPE_CODE_UNDEF:
 493     case TYPE_CODE_BOOL:
 494     case TYPE_CODE_CHAR:
 495     default:
 496       generic_val_print (type, embedded_offset, address,
 497                          stream, recurse, original_value, options,
 498                          &m2_decorations);
 499       break;
 500     }
 501 }