gdb/m2-valprint.c

   1 /* Support for printing Modula 2 values for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2020 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 #include "cli/cli-style.h"
  32
  33 static int print_unpacked_pointer (struct type *type,
  34                                    CORE_ADDR address, CORE_ADDR addr,
  35                                    const struct value_print_options *options,
  36                                    struct ui_file *stream);
  37 static void
  38 m2_print_array_contents (struct type *type, const gdb_byte *valaddr,
  39                          int embedded_offset, CORE_ADDR address,
  40                          struct ui_file *stream, int recurse,
  41                          struct value *val,
  42                          const struct value_print_options *options,
  43                          int len);
  44
  45
  46 /* get_long_set_bounds - assigns the bounds of the long set to low and
  47                          high.  */
  48
  49 int
  50 get_long_set_bounds (struct type *type, LONGEST *low, LONGEST *high)
  51 {
  52   int len, i;
  53
  54   if (TYPE_CODE (type) == TYPE_CODE_STRUCT)
  55     {
  56       len = TYPE_NFIELDS (type);
  57       i = TYPE_N_BASECLASSES (type);
  58       if (len == 0)
  59         return 0;
  60       *low = TYPE_LOW_BOUND (TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type, i)));
  61       *high = TYPE_HIGH_BOUND (TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type,
  62                                                                  len-1)));
  63       return 1;
  64     }
  65   error (_("expecting long_set"));
  66   return 0;
  67 }
  68
  69 static void
  70 m2_print_long_set (struct type *type, const gdb_byte *valaddr,
  71                    int embedded_offset, CORE_ADDR address,
  72                    struct ui_file *stream)
  73 {
  74   int empty_set        = 1;
  75   int element_seen     = 0;
  76   LONGEST previous_low = 0;
  77   LONGEST previous_high= 0;
  78   LONGEST i, low_bound, high_bound;
  79   LONGEST field_low, field_high;
  80   struct type *range;
  81   int len, field;
  82   struct type *target;
  83   int bitval;
  84
  85   type = check_typedef (type);
  86
  87   fprintf_filtered (stream, "{");
  88   len = TYPE_NFIELDS (type);
  89   if (get_long_set_bounds (type, &low_bound, &high_bound))
  90     {
  91       field = TYPE_N_BASECLASSES (type);
  92       range = TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type, field));
  93     }
  94   else
  95     {
  96       fprintf_styled (stream, metadata_style.style (),
  97                       " %s }", _("<unknown bounds of set>"));
  98       return;
  99     }
 100
 101   target = TYPE_TARGET_TYPE (range);
 102
 103   if (get_discrete_bounds (range, &field_low, &field_high) >= 0)
 104     {
 105       for (i = low_bound; i <= high_bound; i++)
 106         {
 107           bitval = value_bit_index (TYPE_FIELD_TYPE (type, field),
 108                                     (TYPE_FIELD_BITPOS (type, field) / 8) +
 109                                     valaddr + embedded_offset, i);
 110           if (bitval < 0)
 111             error (_("bit test is out of range"));
 112           else if (bitval > 0)
 113             {
 114               previous_high = i;
 115               if (! element_seen)
 116                 {
 117                   if (! empty_set)
 118                     fprintf_filtered (stream, ", ");
 119                   print_type_scalar (target, i, stream);
 120                   empty_set    = 0;
 121                   element_seen = 1;
 122                   previous_low = i;
 123                 }
 124             }
 125           else
 126             {
 127               /* bit is not set */
 128               if (element_seen)
 129                 {
 130                   if (previous_low+1 < previous_high)
 131                     fprintf_filtered (stream, "..");
 132                   if (previous_low+1 < previous_high)
 133                     print_type_scalar (target, previous_high, stream);
 134                   element_seen = 0;
 135                 }
 136             }
 137           if (i == field_high)
 138             {
 139               field++;
 140               if (field == len)
 141                 break;
 142               range = TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type, field));
 143               if (get_discrete_bounds (range, &field_low, &field_high) < 0)
 144                 break;
 145               target = TYPE_TARGET_TYPE (range);
 146             }
 147         }
 148       if (element_seen)
 149         {
 150           if (previous_low+1 < previous_high)
 151             {
 152               fprintf_filtered (stream, "..");
 153               print_type_scalar (target, previous_high, stream);
 154             }
 155           element_seen = 0;
 156         }
 157       fprintf_filtered (stream, "}");
 158     }
 159 }
 160
 161 static void
 162 m2_print_unbounded_array (struct type *type, const gdb_byte *valaddr,
 163                           int embedded_offset, CORE_ADDR address,
 164                           struct ui_file *stream, int recurse,
 165                           const struct value_print_options *options)
 166 {
 167   CORE_ADDR addr;
 168   LONGEST len;
 169   struct value *val;
 170
 171   type = check_typedef (type);
 172
 173   addr = unpack_pointer (TYPE_FIELD_TYPE (type, 0),
 174                          (TYPE_FIELD_BITPOS (type, 0) / 8) +
 175                          valaddr + embedded_offset);
 176
 177   val = value_at_lazy (TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 0)),
 178                        addr);
 179   len = unpack_field_as_long (type, valaddr + embedded_offset, 1);
 180
 181   fprintf_filtered (stream, "{");
 182   m2_print_array_contents (value_type (val),
 183                            value_contents_for_printing (val),
 184                            value_embedded_offset (val), addr, stream,
 185                            recurse, val, options, len);
 186   fprintf_filtered (stream, ", HIGH = %d}", (int) len);
 187 }
 188
 189 static int
 190 print_unpacked_pointer (struct type *type,
 191                         CORE_ADDR address, CORE_ADDR addr,
 192                         const struct value_print_options *options,
 193                         struct ui_file *stream)
 194 {
 195   struct gdbarch *gdbarch = get_type_arch (type);
 196   struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
 197   int want_space = 0;
 198
 199   if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
 200     {
 201       /* Try to print what function it points to.  */
 202       print_function_pointer_address (options, gdbarch, addr, stream);
 203       /* Return value is irrelevant except for string pointers.  */
 204       return 0;
 205     }
 206
 207   if (options->addressprint && options->format != 's')
 208     {
 209       fputs_filtered (paddress (gdbarch, address), stream);
 210       want_space = 1;
 211     }
 212
 213   /* For a pointer to char or unsigned char, also print the string
 214      pointed to, unless pointer is null.  */
 215
 216   if (TYPE_LENGTH (elttype) == 1
 217       && TYPE_CODE (elttype) == TYPE_CODE_INT
 218       && (options->format == 0 || options->format == 's')
 219       && addr != 0)
 220     {
 221       if (want_space)
 222         fputs_filtered (" ", stream);
 223       return val_print_string (TYPE_TARGET_TYPE (type), NULL, addr, -1,
 224                                stream, options);
 225     }
 226
 227   return 0;
 228 }
 229
 230 static void
 231 print_variable_at_address (struct type *type,
 232                            const gdb_byte *valaddr,
 233                            struct ui_file *stream,
 234                            int recurse,
 235                            const struct value_print_options *options)
 236 {
 237   struct gdbarch *gdbarch = get_type_arch (type);
 238   CORE_ADDR addr = unpack_pointer (type, valaddr);
 239   struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
 240
 241   fprintf_filtered (stream, "[");
 242   fputs_filtered (paddress (gdbarch, addr), stream);
 243   fprintf_filtered (stream, "] : ");
 244
 245   if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
 246     {
 247       struct value *deref_val =
 248         value_at (TYPE_TARGET_TYPE (type), unpack_pointer (type, valaddr));
 249
 250       common_val_print (deref_val, stream, recurse, options, current_language);
 251     }
 252   else
 253     fputs_filtered ("???", stream);
 254 }
 255
 256
 257 /* m2_print_array_contents - prints out the contents of an
 258                              array up to a max_print values.
 259                              It prints arrays of char as a string
 260                              and all other data types as comma
 261                              separated values.  */
 262
 263 static void
 264 m2_print_array_contents (struct type *type, const gdb_byte *valaddr,
 265                          int embedded_offset, CORE_ADDR address,
 266                          struct ui_file *stream, int recurse,
 267                          struct value *val,
 268                          const struct value_print_options *options,
 269                          int len)
 270 {
 271   type = check_typedef (type);
 272
 273   if (TYPE_LENGTH (type) > 0)
 274     {
 275       if (options->prettyformat_arrays)
 276         print_spaces_filtered (2 + 2 * recurse, stream);
 277       /* For an array of chars, print with string syntax.  */
 278       if (TYPE_LENGTH (type) == 1 &&
 279           ((TYPE_CODE (type) == TYPE_CODE_INT)
 280            || ((current_language->la_language == language_m2)
 281                && (TYPE_CODE (type) == TYPE_CODE_CHAR)))
 282           && (options->format == 0 || options->format == 's'))
 283         val_print_string (type, NULL, address, len+1, stream, options);
 284       else
 285         {
 286           fprintf_filtered (stream, "{");
 287           val_print_array_elements (type, embedded_offset,
 288                                     address, stream, recurse, val,
 289                                     options, 0);
 290           fprintf_filtered (stream, "}");
 291         }
 292     }
 293 }
 294
 295 /* Decorations for Modula 2.  */
 296
 297 static const struct generic_val_print_decorations m2_decorations =
 298 {
 299   "",
 300   " + ",
 301   " * I",
 302   "TRUE",
 303   "FALSE",
 304   "void",
 305   "{",
 306   "}"
 307 };
 308
 309 /* See val_print for a description of the various parameters of this
 310    function; they are identical.  */
 311
 312 void
 313 m2_val_print (struct type *type, int embedded_offset,
 314               CORE_ADDR address, struct ui_file *stream, int recurse,
 315               struct value *original_value,
 316               const struct value_print_options *options)
 317 {
 318   unsigned len;
 319   struct type *elttype;
 320   CORE_ADDR addr;
 321   const gdb_byte *valaddr = value_contents_for_printing (original_value);
 322
 323   type = check_typedef (type);
 324   switch (TYPE_CODE (type))
 325     {
 326     case TYPE_CODE_ARRAY:
 327       if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
 328         {
 329           elttype = check_typedef (TYPE_TARGET_TYPE (type));
 330           len = TYPE_LENGTH (type) / TYPE_LENGTH (elttype);
 331           if (options->prettyformat_arrays)
 332             print_spaces_filtered (2 + 2 * recurse, stream);
 333           /* For an array of chars, print with string syntax.  */
 334           if (TYPE_LENGTH (elttype) == 1 &&
 335               ((TYPE_CODE (elttype) == TYPE_CODE_INT)
 336                || ((current_language->la_language == language_m2)
 337                    && (TYPE_CODE (elttype) == TYPE_CODE_CHAR)))
 338               && (options->format == 0 || options->format == 's'))
 339             {
 340               /* If requested, look for the first null char and only print
 341                  elements up to it.  */
 342               if (options->stop_print_at_null)
 343                 {
 344                   unsigned int temp_len;
 345
 346                   /* Look for a NULL char.  */
 347                   for (temp_len = 0;
 348                        (valaddr + embedded_offset)[temp_len]
 349                          && temp_len < len && temp_len < options->print_max;
 350                        temp_len++);
 351                   len = temp_len;
 352                 }
 353
 354               LA_PRINT_STRING (stream, TYPE_TARGET_TYPE (type),
 355                                valaddr + embedded_offset, len, NULL,
 356                                0, options);
 357             }
 358           else
 359             {
 360               fprintf_filtered (stream, "{");
 361               val_print_array_elements (type, embedded_offset,
 362                                         address, stream,
 363                                         recurse, original_value,
 364                                         options, 0);
 365               fprintf_filtered (stream, "}");
 366             }
 367           break;
 368         }
 369       /* Array of unspecified length: treat like pointer to first elt.  */
 370       print_unpacked_pointer (type, address, address, options, stream);
 371       break;
 372
 373     case TYPE_CODE_PTR:
 374       if (TYPE_CONST (type))
 375         print_variable_at_address (type, valaddr + embedded_offset,
 376                                    stream, recurse, options);
 377       else if (options->format && options->format != 's')
 378         val_print_scalar_formatted (type, embedded_offset,
 379                                     original_value, options, 0, stream);
 380       else
 381         {
 382           addr = unpack_pointer (type, valaddr + embedded_offset);
 383           print_unpacked_pointer (type, addr, address, options, stream);
 384         }
 385       break;
 386
 387     case TYPE_CODE_UNION:
 388       if (recurse && !options->unionprint)
 389         {
 390           fprintf_filtered (stream, "{...}");
 391           break;
 392         }
 393       /* Fall through.  */
 394     case TYPE_CODE_STRUCT:
 395       if (m2_is_long_set (type))
 396         m2_print_long_set (type, valaddr, embedded_offset, address,
 397                            stream);
 398       else if (m2_is_unbounded_array (type))
 399         m2_print_unbounded_array (type, valaddr, embedded_offset,
 400                                   address, stream, recurse, options);
 401       else
 402         cp_print_value_fields (type, type, embedded_offset,
 403                                address, stream, recurse, original_value,
 404                                options, NULL, 0);
 405       break;
 406
 407     case TYPE_CODE_SET:
 408       elttype = TYPE_INDEX_TYPE (type);
 409       elttype = check_typedef (elttype);
 410       if (TYPE_STUB (elttype))
 411         {
 412           fprintf_styled (stream, metadata_style.style (),
 413                           _("<incomplete type>"));
 414           break;
 415         }
 416       else
 417         {
 418           struct type *range = elttype;
 419           LONGEST low_bound, high_bound;
 420           int i;
 421           int need_comma = 0;
 422
 423           fputs_filtered ("{", stream);
 424
 425           i = get_discrete_bounds (range, &low_bound, &high_bound);
 426         maybe_bad_bstring:
 427           if (i < 0)
 428             {
 429               fputs_styled (_("<error value>"), metadata_style.style (),
 430                             stream);
 431               goto done;
 432             }
 433
 434           for (i = low_bound; i <= high_bound; i++)
 435             {
 436               int element = value_bit_index (type, valaddr + embedded_offset,
 437                                              i);
 438
 439               if (element < 0)
 440                 {
 441                   i = element;
 442                   goto maybe_bad_bstring;
 443                 }
 444               if (element)
 445                 {
 446                   if (need_comma)
 447                     fputs_filtered (", ", stream);
 448                   print_type_scalar (range, i, stream);
 449                   need_comma = 1;
 450
 451                   if (i + 1 <= high_bound
 452                       && value_bit_index (type, valaddr + embedded_offset,
 453                                           ++i))
 454                     {
 455                       int j = i;
 456
 457                       fputs_filtered ("..", stream);
 458                       while (i + 1 <= high_bound
 459                              && value_bit_index (type,
 460                                                  valaddr + embedded_offset,
 461                                                  ++i))
 462                         j = i;
 463                       print_type_scalar (range, j, stream);
 464                     }
 465                 }
 466             }
 467         done:
 468           fputs_filtered ("}", stream);
 469         }
 470       break;
 471
 472     case TYPE_CODE_RANGE:
 473       if (TYPE_LENGTH (type) == TYPE_LENGTH (TYPE_TARGET_TYPE (type)))
 474         {
 475           m2_val_print (TYPE_TARGET_TYPE (type), embedded_offset,
 476                         address, stream, recurse, original_value, options);
 477           break;
 478         }
 479       /* FIXME: create_static_range_type does not set the unsigned bit in a
 480          range type (I think it probably should copy it from the target
 481          type), so we won't print values which are too large to
 482          fit in a signed integer correctly.  */
 483       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
 484          print with the target type, though, because the size of our type
 485          and the target type might differ).  */
 486       /* FALLTHROUGH */
 487
 488     case TYPE_CODE_REF:
 489     case TYPE_CODE_ENUM:
 490     case TYPE_CODE_FUNC:
 491     case TYPE_CODE_INT:
 492     case TYPE_CODE_FLT:
 493     case TYPE_CODE_METHOD:
 494     case TYPE_CODE_VOID:
 495     case TYPE_CODE_ERROR:
 496     case TYPE_CODE_UNDEF:
 497     case TYPE_CODE_BOOL:
 498     case TYPE_CODE_CHAR:
 499     default:
 500       generic_val_print (type, embedded_offset, address,
 501                          stream, recurse, original_value, options,
 502                          &m2_decorations);
 503       break;
 504     }
 505 }