gdb/m2-valprint.c

   1 /* Support for printing Modula 2 values for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2023 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->field (i).type ()->bounds ()->low.const_val ();
  59       *high = type->field (len - 1).type ()->bounds ()->high.const_val ();
  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   gdb_printf (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 = range->target_type ();
  99
 100   if (get_discrete_bounds (range, &field_low, &field_high))
 101     {
 102       for (i = low_bound; i <= high_bound; i++)
 103         {
 104           bitval = value_bit_index (type->field (field).type (),
 105                                     (type->field (field).loc_bitpos () / 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                     gdb_printf (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                     gdb_printf (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))
 141                 break;
 142               target = range->target_type ();
 143             }
 144         }
 145       if (element_seen)
 146         {
 147           if (previous_low+1 < previous_high)
 148             {
 149               gdb_printf (stream, "..");
 150               print_type_scalar (target, previous_high, stream);
 151             }
 152           element_seen = 0;
 153         }
 154       gdb_printf (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 ());
 168   const gdb_byte *valaddr = value->contents_for_printing ().data ();
 169
 170   addr = unpack_pointer (type->field (0).type (),
 171                          (type->field (0).loc_bitpos () / 8) +
 172                          valaddr);
 173
 174   val = value_at_lazy (type->field (0).type ()->target_type (),
 175                        addr);
 176   len = unpack_field_as_long (type, valaddr, 1);
 177
 178   gdb_printf (stream, "{");
 179   m2_print_array_contents (val, stream, recurse, options, len);
 180   gdb_printf (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 = type->arch ();
 190   struct type *elttype = check_typedef (type->target_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       gdb_puts (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 (elttype->length () == 1
 211       && elttype->code () == TYPE_CODE_INT
 212       && (options->format == 0 || options->format == 's')
 213       && addr != 0)
 214     {
 215       if (want_space)
 216         gdb_puts (" ", stream);
 217       return val_print_string (type->target_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 = type->arch ();
 232   CORE_ADDR addr = unpack_pointer (type, valaddr);
 233   struct type *elttype = check_typedef (type->target_type ());
 234
 235   gdb_printf (stream, "[");
 236   gdb_puts (paddress (gdbarch, addr), stream);
 237   gdb_printf (stream, "] : ");
 238
 239   if (elttype->code () != TYPE_CODE_UNDEF)
 240     {
 241       struct value *deref_val =
 242         value_at (type->target_type (), unpack_pointer (type, valaddr));
 243
 244       common_val_print (deref_val, stream, recurse, options, current_language);
 245     }
 246   else
 247     gdb_puts ("???", 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 (val->type ());
 264
 265   if (type->length () > 0)
 266     {
 267       /* For an array of chars, print with string syntax.  */
 268       if (type->length () == 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, val->address (), len+1, stream,
 274                           options);
 275       else
 276         {
 277           gdb_printf (stream, "{");
 278           value_print_array_elements (val, stream, recurse, options, 0);
 279           gdb_printf (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_language::value_print_inner (struct value *val, struct ui_file *stream,
 302                                 int recurse,
 303                                 const struct value_print_options *options) const
 304 {
 305   unsigned len;
 306   struct type *elttype;
 307   CORE_ADDR addr;
 308   const gdb_byte *valaddr = val->contents_for_printing ().data ();
 309   const CORE_ADDR address = val->address ();
 310
 311   struct type *type = check_typedef (val->type ());
 312   switch (type->code ())
 313     {
 314     case TYPE_CODE_ARRAY:
 315       if (type->length () > 0 && type->target_type ()->length () > 0)
 316         {
 317           elttype = check_typedef (type->target_type ());
 318           len = type->length () / elttype->length ();
 319           /* For an array of chars, print with string syntax.  */
 320           if (elttype->length () == 1 &&
 321               ((elttype->code () == TYPE_CODE_INT)
 322                || ((current_language->la_language == language_m2)
 323                    && (elttype->code () == TYPE_CODE_CHAR)))
 324               && (options->format == 0 || options->format == 's'))
 325             {
 326               /* If requested, look for the first null char and only print
 327                  elements up to it.  */
 328               if (options->stop_print_at_null)
 329                 {
 330                   unsigned int print_max_chars = get_print_max_chars (options);
 331                   unsigned int temp_len;
 332
 333                   /* Look for a NULL char.  */
 334                   for (temp_len = 0;
 335                        (valaddr[temp_len]
 336                         && temp_len < len
 337                         && temp_len < print_max_chars);
 338                        temp_len++);
 339                   len = temp_len;
 340                 }
 341
 342               printstr (stream, type->target_type (), valaddr, len,
 343                         NULL, 0, options);
 344             }
 345           else
 346             {
 347               gdb_printf (stream, "{");
 348               value_print_array_elements (val, stream, recurse,
 349                                           options, 0);
 350               gdb_printf (stream, "}");
 351             }
 352           break;
 353         }
 354       /* Array of unspecified length: treat like pointer to first elt.  */
 355       print_unpacked_pointer (type, address, address, options, stream);
 356       break;
 357
 358     case TYPE_CODE_PTR:
 359       if (TYPE_CONST (type))
 360         print_variable_at_address (type, valaddr, stream, recurse, options);
 361       else if (options->format && options->format != 's')
 362         value_print_scalar_formatted (val, options, 0, stream);
 363       else
 364         {
 365           addr = unpack_pointer (type, valaddr);
 366           print_unpacked_pointer (type, addr, address, options, stream);
 367         }
 368       break;
 369
 370     case TYPE_CODE_UNION:
 371       if (recurse && !options->unionprint)
 372         {
 373           gdb_printf (stream, "{...}");
 374           break;
 375         }
 376       /* Fall through.  */
 377     case TYPE_CODE_STRUCT:
 378       if (m2_is_long_set (type))
 379         m2_print_long_set (type, valaddr, 0, address, stream);
 380       else if (m2_is_unbounded_array (type))
 381         m2_print_unbounded_array (val, stream, recurse, options);
 382       else
 383         cp_print_value_fields (val, stream, recurse, options, NULL, 0);
 384       break;
 385
 386     case TYPE_CODE_SET:
 387       elttype = type->index_type ();
 388       elttype = check_typedef (elttype);
 389       if (elttype->is_stub ())
 390         {
 391           fprintf_styled (stream, metadata_style.style (),
 392                           _("<incomplete type>"));
 393           break;
 394         }
 395       else
 396         {
 397           struct type *range = elttype;
 398           LONGEST low_bound, high_bound;
 399           int i;
 400           int need_comma = 0;
 401
 402           gdb_puts ("{", stream);
 403
 404           i = get_discrete_bounds (range, &low_bound, &high_bound) ? 0 : -1;
 405         maybe_bad_bstring:
 406           if (i < 0)
 407             {
 408               fputs_styled (_("<error value>"), metadata_style.style (),
 409                             stream);
 410               goto done;
 411             }
 412
 413           for (i = low_bound; i <= high_bound; i++)
 414             {
 415               int element = value_bit_index (type, valaddr, i);
 416
 417               if (element < 0)
 418                 {
 419                   i = element;
 420                   goto maybe_bad_bstring;
 421                 }
 422               if (element)
 423                 {
 424                   if (need_comma)
 425                     gdb_puts (", ", stream);
 426                   print_type_scalar (range, i, stream);
 427                   need_comma = 1;
 428
 429                   if (i + 1 <= high_bound
 430                       && value_bit_index (type, valaddr, ++i))
 431                     {
 432                       int j = i;
 433
 434                       gdb_puts ("..", stream);
 435                       while (i + 1 <= high_bound
 436                              && value_bit_index (type, valaddr, ++i))
 437                         j = i;
 438                       print_type_scalar (range, j, stream);
 439                     }
 440                 }
 441             }
 442         done:
 443           gdb_puts ("}", stream);
 444         }
 445       break;
 446
 447     case TYPE_CODE_RANGE:
 448       if (type->length () == type->target_type ()->length ())
 449         {
 450           struct value *v = value_cast (type->target_type (), val);
 451           value_print_inner (v, stream, recurse, options);
 452           break;
 453         }
 454       /* FALLTHROUGH */
 455
 456     case TYPE_CODE_REF:
 457     case TYPE_CODE_ENUM:
 458     case TYPE_CODE_FUNC:
 459     case TYPE_CODE_INT:
 460     case TYPE_CODE_FLT:
 461     case TYPE_CODE_METHOD:
 462     case TYPE_CODE_VOID:
 463     case TYPE_CODE_ERROR:
 464     case TYPE_CODE_UNDEF:
 465     case TYPE_CODE_BOOL:
 466     case TYPE_CODE_CHAR:
 467     default:
 468       generic_value_print (val, stream, recurse, options, &m2_decorations);
 469       break;
 470     }
 471 }