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 value *val,
  39                          struct ui_file *stream, int recurse,
  40                          const struct value_print_options *options,
  41                          int len);
  42
  43
  44 /* get_long_set_bounds - assigns the bounds of the long set to low and
  45                          high.  */
  46
  47 int
  48 get_long_set_bounds (struct type *type, LONGEST *low, LONGEST *high)
  49 {
  50   int len, i;
  51
  52   if (type->code () == TYPE_CODE_STRUCT)
  53     {
  54       len = type->num_fields ();
  55       i = TYPE_N_BASECLASSES (type);
  56       if (len == 0)
  57         return 0;
  58       *low = TYPE_LOW_BOUND (type->field (i).type ()->index_type ());
  59       *high = TYPE_HIGH_BOUND (type->field (len - 1).type ()->index_type ());
  60       return 1;
  61     }
  62   error (_("expecting long_set"));
  63   return 0;
  64 }
  65
  66 static void
  67 m2_print_long_set (struct type *type, const gdb_byte *valaddr,
  68                    int embedded_offset, CORE_ADDR address,
  69                    struct ui_file *stream)
  70 {
  71   int empty_set        = 1;
  72   int element_seen     = 0;
  73   LONGEST previous_low = 0;
  74   LONGEST previous_high= 0;
  75   LONGEST i, low_bound, high_bound;
  76   LONGEST field_low, field_high;
  77   struct type *range;
  78   int len, field;
  79   struct type *target;
  80   int bitval;
  81
  82   type = check_typedef (type);
  83
  84   fprintf_filtered (stream, "{");
  85   len = type->num_fields ();
  86   if (get_long_set_bounds (type, &low_bound, &high_bound))
  87     {
  88       field = TYPE_N_BASECLASSES (type);
  89       range = type->field (field).type ()->index_type ();
  90     }
  91   else
  92     {
  93       fprintf_styled (stream, metadata_style.style (),
  94                       " %s }", _("<unknown bounds of set>"));
  95       return;
  96     }
  97
  98   target = TYPE_TARGET_TYPE (range);
  99
 100   if (get_discrete_bounds (range, &field_low, &field_high) >= 0)
 101     {
 102       for (i = low_bound; i <= high_bound; i++)
 103         {
 104           bitval = value_bit_index (type->field (field).type (),
 105                                     (TYPE_FIELD_BITPOS (type, field) / 8) +
 106                                     valaddr + embedded_offset, i);
 107           if (bitval < 0)
 108             error (_("bit test is out of range"));
 109           else if (bitval > 0)
 110             {
 111               previous_high = i;
 112               if (! element_seen)
 113                 {
 114                   if (! empty_set)
 115                     fprintf_filtered (stream, ", ");
 116                   print_type_scalar (target, i, stream);
 117                   empty_set    = 0;
 118                   element_seen = 1;
 119                   previous_low = i;
 120                 }
 121             }
 122           else
 123             {
 124               /* bit is not set */
 125               if (element_seen)
 126                 {
 127                   if (previous_low+1 < previous_high)
 128                     fprintf_filtered (stream, "..");
 129                   if (previous_low+1 < previous_high)
 130                     print_type_scalar (target, previous_high, stream);
 131                   element_seen = 0;
 132                 }
 133             }
 134           if (i == field_high)
 135             {
 136               field++;
 137               if (field == len)
 138                 break;
 139               range = type->field (field).type ()->index_type ();
 140               if (get_discrete_bounds (range, &field_low, &field_high) < 0)
 141                 break;
 142               target = TYPE_TARGET_TYPE (range);
 143             }
 144         }
 145       if (element_seen)
 146         {
 147           if (previous_low+1 < previous_high)
 148             {
 149               fprintf_filtered (stream, "..");
 150               print_type_scalar (target, previous_high, stream);
 151             }
 152           element_seen = 0;
 153         }
 154       fprintf_filtered (stream, "}");
 155     }
 156 }
 157
 158 static void
 159 m2_print_unbounded_array (struct value *value,
 160                           struct ui_file *stream, int recurse,
 161                           const struct value_print_options *options)
 162 {
 163   CORE_ADDR addr;
 164   LONGEST len;
 165   struct value *val;
 166
 167   struct type *type = check_typedef (value_type (value));
 168   const gdb_byte *valaddr = value_contents_for_printing (value);
 169
 170   addr = unpack_pointer (type->field (0).type (),
 171                          (TYPE_FIELD_BITPOS (type, 0) / 8) +
 172                          valaddr);
 173
 174   val = value_at_lazy (TYPE_TARGET_TYPE (type->field (0).type ()),
 175                        addr);
 176   len = unpack_field_as_long (type, valaddr, 1);
 177
 178   fprintf_filtered (stream, "{");
 179   m2_print_array_contents (val, stream, recurse, options, len);
 180   fprintf_filtered (stream, ", HIGH = %d}", (int) len);
 181 }
 182
 183 static int
 184 print_unpacked_pointer (struct type *type,
 185                         CORE_ADDR address, CORE_ADDR addr,
 186                         const struct value_print_options *options,
 187                         struct ui_file *stream)
 188 {
 189   struct gdbarch *gdbarch = get_type_arch (type);
 190   struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
 191   int want_space = 0;
 192
 193   if (elttype->code () == TYPE_CODE_FUNC)
 194     {
 195       /* Try to print what function it points to.  */
 196       print_function_pointer_address (options, gdbarch, addr, stream);
 197       /* Return value is irrelevant except for string pointers.  */
 198       return 0;
 199     }
 200
 201   if (options->addressprint && options->format != 's')
 202     {
 203       fputs_filtered (paddress (gdbarch, address), stream);
 204       want_space = 1;
 205     }
 206
 207   /* For a pointer to char or unsigned char, also print the string
 208      pointed to, unless pointer is null.  */
 209
 210   if (TYPE_LENGTH (elttype) == 1
 211       && elttype->code () == TYPE_CODE_INT
 212       && (options->format == 0 || options->format == 's')
 213       && addr != 0)
 214     {
 215       if (want_space)
 216         fputs_filtered (" ", stream);
 217       return val_print_string (TYPE_TARGET_TYPE (type), NULL, addr, -1,
 218                                stream, options);
 219     }
 220
 221   return 0;
 222 }
 223
 224 static void
 225 print_variable_at_address (struct type *type,
 226                            const gdb_byte *valaddr,
 227                            struct ui_file *stream,
 228                            int recurse,
 229                            const struct value_print_options *options)
 230 {
 231   struct gdbarch *gdbarch = get_type_arch (type);
 232   CORE_ADDR addr = unpack_pointer (type, valaddr);
 233   struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
 234
 235   fprintf_filtered (stream, "[");
 236   fputs_filtered (paddress (gdbarch, addr), stream);
 237   fprintf_filtered (stream, "] : ");
 238
 239   if (elttype->code () != TYPE_CODE_UNDEF)
 240     {
 241       struct value *deref_val =
 242         value_at (TYPE_TARGET_TYPE (type), unpack_pointer (type, valaddr));
 243
 244       common_val_print (deref_val, stream, recurse, options, current_language);
 245     }
 246   else
 247     fputs_filtered ("???", stream);
 248 }
 249
 250
 251 /* m2_print_array_contents - prints out the contents of an
 252                              array up to a max_print values.
 253                              It prints arrays of char as a string
 254                              and all other data types as comma
 255                              separated values.  */
 256
 257 static void
 258 m2_print_array_contents (struct value *val,
 259                          struct ui_file *stream, int recurse,
 260                          const struct value_print_options *options,
 261                          int len)
 262 {
 263   struct type *type = check_typedef (value_type (val));
 264
 265   if (TYPE_LENGTH (type) > 0)
 266     {
 267       /* For an array of chars, print with string syntax.  */
 268       if (TYPE_LENGTH (type) == 1 &&
 269           ((type->code () == TYPE_CODE_INT)
 270            || ((current_language->la_language == language_m2)
 271                && (type->code () == TYPE_CODE_CHAR)))
 272           && (options->format == 0 || options->format == 's'))
 273         val_print_string (type, NULL, value_address (val), len+1, stream,
 274                           options);
 275       else
 276         {
 277           fprintf_filtered (stream, "{");
 278           value_print_array_elements (val, stream, recurse, options, 0);
 279           fprintf_filtered (stream, "}");
 280         }
 281     }
 282 }
 283
 284 /* Decorations for Modula 2.  */
 285
 286 static const struct generic_val_print_decorations m2_decorations =
 287 {
 288   "",
 289   " + ",
 290   " * I",
 291   "TRUE",
 292   "FALSE",
 293   "void",
 294   "{",
 295   "}"
 296 };
 297
 298 /* See m2-lang.h.  */
 299
 300 void
 301 m2_value_print_inner (struct value *val, struct ui_file *stream, int recurse,
 302                       const struct value_print_options *options)
 303 {
 304   unsigned len;
 305   struct type *elttype;
 306   CORE_ADDR addr;
 307   const gdb_byte *valaddr = value_contents_for_printing (val);
 308   const CORE_ADDR address = value_address (val);
 309
 310   struct type *type = check_typedef (value_type (val));
 311   switch (type->code ())
 312     {
 313     case TYPE_CODE_ARRAY:
 314       if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
 315         {
 316           elttype = check_typedef (TYPE_TARGET_TYPE (type));
 317           len = TYPE_LENGTH (type) / TYPE_LENGTH (elttype);
 318           /* For an array of chars, print with string syntax.  */
 319           if (TYPE_LENGTH (elttype) == 1 &&
 320               ((elttype->code () == TYPE_CODE_INT)
 321                || ((current_language->la_language == language_m2)
 322                    && (elttype->code () == TYPE_CODE_CHAR)))
 323               && (options->format == 0 || options->format == 's'))
 324             {
 325               /* If requested, look for the first null char and only print
 326                  elements up to it.  */
 327               if (options->stop_print_at_null)
 328                 {
 329                   unsigned int temp_len;
 330
 331                   /* Look for a NULL char.  */
 332                   for (temp_len = 0;
 333                        (valaddr[temp_len]
 334                         && temp_len < len && temp_len < options->print_max);
 335                        temp_len++);
 336                   len = temp_len;
 337                 }
 338
 339               LA_PRINT_STRING (stream, TYPE_TARGET_TYPE (type),
 340                                valaddr, len, NULL, 0, options);
 341             }
 342           else
 343             {
 344               fprintf_filtered (stream, "{");
 345               value_print_array_elements (val, stream, recurse,
 346                                           options, 0);
 347               fprintf_filtered (stream, "}");
 348             }
 349           break;
 350         }
 351       /* Array of unspecified length: treat like pointer to first elt.  */
 352       print_unpacked_pointer (type, address, address, options, stream);
 353       break;
 354
 355     case TYPE_CODE_PTR:
 356       if (TYPE_CONST (type))
 357         print_variable_at_address (type, valaddr, stream, recurse, options);
 358       else if (options->format && options->format != 's')
 359         value_print_scalar_formatted (val, options, 0, stream);
 360       else
 361         {
 362           addr = unpack_pointer (type, valaddr);
 363           print_unpacked_pointer (type, addr, address, options, stream);
 364         }
 365       break;
 366
 367     case TYPE_CODE_UNION:
 368       if (recurse && !options->unionprint)
 369         {
 370           fprintf_filtered (stream, "{...}");
 371           break;
 372         }
 373       /* Fall through.  */
 374     case TYPE_CODE_STRUCT:
 375       if (m2_is_long_set (type))
 376         m2_print_long_set (type, valaddr, 0, address, stream);
 377       else if (m2_is_unbounded_array (type))
 378         m2_print_unbounded_array (val, stream, recurse, options);
 379       else
 380         cp_print_value_fields (val, stream, recurse, options, NULL, 0);
 381       break;
 382
 383     case TYPE_CODE_SET:
 384       elttype = type->index_type ();
 385       elttype = check_typedef (elttype);
 386       if (TYPE_STUB (elttype))
 387         {
 388           fprintf_styled (stream, metadata_style.style (),
 389                           _("<incomplete type>"));
 390           break;
 391         }
 392       else
 393         {
 394           struct type *range = elttype;
 395           LONGEST low_bound, high_bound;
 396           int i;
 397           int need_comma = 0;
 398
 399           fputs_filtered ("{", stream);
 400
 401           i = get_discrete_bounds (range, &low_bound, &high_bound);
 402         maybe_bad_bstring:
 403           if (i < 0)
 404             {
 405               fputs_styled (_("<error value>"), metadata_style.style (),
 406                             stream);
 407               goto done;
 408             }
 409
 410           for (i = low_bound; i <= high_bound; i++)
 411             {
 412               int element = value_bit_index (type, valaddr, i);
 413
 414               if (element < 0)
 415                 {
 416                   i = element;
 417                   goto maybe_bad_bstring;
 418                 }
 419               if (element)
 420                 {
 421                   if (need_comma)
 422                     fputs_filtered (", ", stream);
 423                   print_type_scalar (range, i, stream);
 424                   need_comma = 1;
 425
 426                   if (i + 1 <= high_bound
 427                       && value_bit_index (type, valaddr, ++i))
 428                     {
 429                       int j = i;
 430
 431                       fputs_filtered ("..", stream);
 432                       while (i + 1 <= high_bound
 433                              && value_bit_index (type, valaddr, ++i))
 434                         j = i;
 435                       print_type_scalar (range, j, stream);
 436                     }
 437                 }
 438             }
 439         done:
 440           fputs_filtered ("}", stream);
 441         }
 442       break;
 443
 444     case TYPE_CODE_RANGE:
 445       if (TYPE_LENGTH (type) == TYPE_LENGTH (TYPE_TARGET_TYPE (type)))
 446         {
 447           struct value *v = value_cast (TYPE_TARGET_TYPE (type), val);
 448           m2_value_print_inner (v, stream, recurse, options);
 449           break;
 450         }
 451       /* FIXME: create_static_range_type does not set the unsigned bit in a
 452          range type (I think it probably should copy it from the target
 453          type), so we won't print values which are too large to
 454          fit in a signed integer correctly.  */
 455       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
 456          print with the target type, though, because the size of our type
 457          and the target type might differ).  */
 458       /* FALLTHROUGH */
 459
 460     case TYPE_CODE_REF:
 461     case TYPE_CODE_ENUM:
 462     case TYPE_CODE_FUNC:
 463     case TYPE_CODE_INT:
 464     case TYPE_CODE_FLT:
 465     case TYPE_CODE_METHOD:
 466     case TYPE_CODE_VOID:
 467     case TYPE_CODE_ERROR:
 468     case TYPE_CODE_UNDEF:
 469     case TYPE_CODE_BOOL:
 470     case TYPE_CODE_CHAR:
 471     default:
 472       generic_value_print (val, stream, recurse, options, &m2_decorations);
 473       break;
 474     }
 475 }