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_INDEX_TYPE (TYPE_FIELD_TYPE (type, i)));
  59       *high = TYPE_HIGH_BOUND (TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type,
  60                                                                  len-1)));
  61       return 1;
  62     }
  63   error (_("expecting long_set"));
  64   return 0;
  65 }
  66
  67 static void
  68 m2_print_long_set (struct type *type, const gdb_byte *valaddr,
  69                    int embedded_offset, CORE_ADDR address,
  70                    struct ui_file *stream)
  71 {
  72   int empty_set        = 1;
  73   int element_seen     = 0;
  74   LONGEST previous_low = 0;
  75   LONGEST previous_high= 0;
  76   LONGEST i, low_bound, high_bound;
  77   LONGEST field_low, field_high;
  78   struct type *range;
  79   int len, field;
  80   struct type *target;
  81   int bitval;
  82
  83   type = check_typedef (type);
  84
  85   fprintf_filtered (stream, "{");
  86   len = type->num_fields ();
  87   if (get_long_set_bounds (type, &low_bound, &high_bound))
  88     {
  89       field = TYPE_N_BASECLASSES (type);
  90       range = TYPE_INDEX_TYPE (TYPE_FIELD_TYPE (type, field));
  91     }
  92   else
  93     {
  94       fprintf_styled (stream, metadata_style.style (),
  95                       " %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 value *value,
 161                           struct ui_file *stream, int recurse,
 162                           const struct value_print_options *options)
 163 {
 164   CORE_ADDR addr;
 165   LONGEST len;
 166   struct value *val;
 167
 168   struct type *type = check_typedef (value_type (value));
 169   const gdb_byte *valaddr = value_contents_for_printing (value);
 170
 171   addr = unpack_pointer (TYPE_FIELD_TYPE (type, 0),
 172                          (TYPE_FIELD_BITPOS (type, 0) / 8) +
 173                          valaddr);
 174
 175   val = value_at_lazy (TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 0)),
 176                        addr);
 177   len = unpack_field_as_long (type, valaddr, 1);
 178
 179   fprintf_filtered (stream, "{");
 180   m2_print_array_contents (val, stream, recurse, options, len);
 181   fprintf_filtered (stream, ", HIGH = %d}", (int) len);
 182 }
 183
 184 static int
 185 print_unpacked_pointer (struct type *type,
 186                         CORE_ADDR address, CORE_ADDR addr,
 187                         const struct value_print_options *options,
 188                         struct ui_file *stream)
 189 {
 190   struct gdbarch *gdbarch = get_type_arch (type);
 191   struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
 192   int want_space = 0;
 193
 194   if (elttype->code () == TYPE_CODE_FUNC)
 195     {
 196       /* Try to print what function it points to.  */
 197       print_function_pointer_address (options, gdbarch, addr, stream);
 198       /* Return value is irrelevant except for string pointers.  */
 199       return 0;
 200     }
 201
 202   if (options->addressprint && options->format != 's')
 203     {
 204       fputs_filtered (paddress (gdbarch, address), stream);
 205       want_space = 1;
 206     }
 207
 208   /* For a pointer to char or unsigned char, also print the string
 209      pointed to, unless pointer is null.  */
 210
 211   if (TYPE_LENGTH (elttype) == 1
 212       && elttype->code () == TYPE_CODE_INT
 213       && (options->format == 0 || options->format == 's')
 214       && addr != 0)
 215     {
 216       if (want_space)
 217         fputs_filtered (" ", stream);
 218       return val_print_string (TYPE_TARGET_TYPE (type), NULL, addr, -1,
 219                                stream, options);
 220     }
 221
 222   return 0;
 223 }
 224
 225 static void
 226 print_variable_at_address (struct type *type,
 227                            const gdb_byte *valaddr,
 228                            struct ui_file *stream,
 229                            int recurse,
 230                            const struct value_print_options *options)
 231 {
 232   struct gdbarch *gdbarch = get_type_arch (type);
 233   CORE_ADDR addr = unpack_pointer (type, valaddr);
 234   struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
 235
 236   fprintf_filtered (stream, "[");
 237   fputs_filtered (paddress (gdbarch, addr), stream);
 238   fprintf_filtered (stream, "] : ");
 239
 240   if (elttype->code () != TYPE_CODE_UNDEF)
 241     {
 242       struct value *deref_val =
 243         value_at (TYPE_TARGET_TYPE (type), unpack_pointer (type, valaddr));
 244
 245       common_val_print (deref_val, stream, recurse, options, current_language);
 246     }
 247   else
 248     fputs_filtered ("???", stream);
 249 }
 250
 251
 252 /* m2_print_array_contents - prints out the contents of an
 253                              array up to a max_print values.
 254                              It prints arrays of char as a string
 255                              and all other data types as comma
 256                              separated values.  */
 257
 258 static void
 259 m2_print_array_contents (struct value *val,
 260                          struct ui_file *stream, int recurse,
 261                          const struct value_print_options *options,
 262                          int len)
 263 {
 264   struct type *type = check_typedef (value_type (val));
 265
 266   if (TYPE_LENGTH (type) > 0)
 267     {
 268       /* For an array of chars, print with string syntax.  */
 269       if (TYPE_LENGTH (type) == 1 &&
 270           ((type->code () == TYPE_CODE_INT)
 271            || ((current_language->la_language == language_m2)
 272                && (type->code () == TYPE_CODE_CHAR)))
 273           && (options->format == 0 || options->format == 's'))
 274         val_print_string (type, NULL, value_address (val), len+1, stream,
 275                           options);
 276       else
 277         {
 278           fprintf_filtered (stream, "{");
 279           value_print_array_elements (val, stream, recurse, options, 0);
 280           fprintf_filtered (stream, "}");
 281         }
 282     }
 283 }
 284
 285 /* Decorations for Modula 2.  */
 286
 287 static const struct generic_val_print_decorations m2_decorations =
 288 {
 289   "",
 290   " + ",
 291   " * I",
 292   "TRUE",
 293   "FALSE",
 294   "void",
 295   "{",
 296   "}"
 297 };
 298
 299 /* See m2-lang.h.  */
 300
 301 void
 302 m2_value_print_inner (struct value *val, struct ui_file *stream, int recurse,
 303                       const struct value_print_options *options)
 304 {
 305   unsigned len;
 306   struct type *elttype;
 307   CORE_ADDR addr;
 308   const gdb_byte *valaddr = value_contents_for_printing (val);
 309   const CORE_ADDR address = value_address (val);
 310
 311   struct type *type = check_typedef (value_type (val));
 312   switch (type->code ())
 313     {
 314     case TYPE_CODE_ARRAY:
 315       if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
 316         {
 317           elttype = check_typedef (TYPE_TARGET_TYPE (type));
 318           len = TYPE_LENGTH (type) / TYPE_LENGTH (elttype);
 319           /* For an array of chars, print with string syntax.  */
 320           if (TYPE_LENGTH (elttype) == 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 temp_len;
 331
 332                   /* Look for a NULL char.  */
 333                   for (temp_len = 0;
 334                        (valaddr[temp_len]
 335                         && temp_len < len && temp_len < options->print_max);
 336                        temp_len++);
 337                   len = temp_len;
 338                 }
 339
 340               LA_PRINT_STRING (stream, TYPE_TARGET_TYPE (type),
 341                                valaddr, len, NULL, 0, options);
 342             }
 343           else
 344             {
 345               fprintf_filtered (stream, "{");
 346               value_print_array_elements (val, stream, recurse,
 347                                           options, 0);
 348               fprintf_filtered (stream, "}");
 349             }
 350           break;
 351         }
 352       /* Array of unspecified length: treat like pointer to first elt.  */
 353       print_unpacked_pointer (type, address, address, options, stream);
 354       break;
 355
 356     case TYPE_CODE_PTR:
 357       if (TYPE_CONST (type))
 358         print_variable_at_address (type, valaddr, stream, recurse, options);
 359       else if (options->format && options->format != 's')
 360         value_print_scalar_formatted (val, options, 0, stream);
 361       else
 362         {
 363           addr = unpack_pointer (type, valaddr);
 364           print_unpacked_pointer (type, addr, address, options, stream);
 365         }
 366       break;
 367
 368     case TYPE_CODE_UNION:
 369       if (recurse && !options->unionprint)
 370         {
 371           fprintf_filtered (stream, "{...}");
 372           break;
 373         }
 374       /* Fall through.  */
 375     case TYPE_CODE_STRUCT:
 376       if (m2_is_long_set (type))
 377         m2_print_long_set (type, valaddr, 0, address, stream);
 378       else if (m2_is_unbounded_array (type))
 379         m2_print_unbounded_array (val, stream, recurse, options);
 380       else
 381         cp_print_value_fields (val, stream, recurse, options, NULL, 0);
 382       break;
 383
 384     case TYPE_CODE_SET:
 385       elttype = TYPE_INDEX_TYPE (type);
 386       elttype = check_typedef (elttype);
 387       if (TYPE_STUB (elttype))
 388         {
 389           fprintf_styled (stream, metadata_style.style (),
 390                           _("<incomplete type>"));
 391           break;
 392         }
 393       else
 394         {
 395           struct type *range = elttype;
 396           LONGEST low_bound, high_bound;
 397           int i;
 398           int need_comma = 0;
 399
 400           fputs_filtered ("{", stream);
 401
 402           i = get_discrete_bounds (range, &low_bound, &high_bound);
 403         maybe_bad_bstring:
 404           if (i < 0)
 405             {
 406               fputs_styled (_("<error value>"), metadata_style.style (),
 407                             stream);
 408               goto done;
 409             }
 410
 411           for (i = low_bound; i <= high_bound; i++)
 412             {
 413               int element = value_bit_index (type, valaddr, i);
 414
 415               if (element < 0)
 416                 {
 417                   i = element;
 418                   goto maybe_bad_bstring;
 419                 }
 420               if (element)
 421                 {
 422                   if (need_comma)
 423                     fputs_filtered (", ", stream);
 424                   print_type_scalar (range, i, stream);
 425                   need_comma = 1;
 426
 427                   if (i + 1 <= high_bound
 428                       && value_bit_index (type, valaddr, ++i))
 429                     {
 430                       int j = i;
 431
 432                       fputs_filtered ("..", stream);
 433                       while (i + 1 <= high_bound
 434                              && value_bit_index (type, valaddr, ++i))
 435                         j = i;
 436                       print_type_scalar (range, j, stream);
 437                     }
 438                 }
 439             }
 440         done:
 441           fputs_filtered ("}", stream);
 442         }
 443       break;
 444
 445     case TYPE_CODE_RANGE:
 446       if (TYPE_LENGTH (type) == TYPE_LENGTH (TYPE_TARGET_TYPE (type)))
 447         {
 448           struct value *v = value_cast (TYPE_TARGET_TYPE (type), val);
 449           m2_value_print_inner (v, stream, recurse, options);
 450           break;
 451         }
 452       /* FIXME: create_static_range_type does not set the unsigned bit in a
 453          range type (I think it probably should copy it from the target
 454          type), so we won't print values which are too large to
 455          fit in a signed integer correctly.  */
 456       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
 457          print with the target type, though, because the size of our type
 458          and the target type might differ).  */
 459       /* FALLTHROUGH */
 460
 461     case TYPE_CODE_REF:
 462     case TYPE_CODE_ENUM:
 463     case TYPE_CODE_FUNC:
 464     case TYPE_CODE_INT:
 465     case TYPE_CODE_FLT:
 466     case TYPE_CODE_METHOD:
 467     case TYPE_CODE_VOID:
 468     case TYPE_CODE_ERROR:
 469     case TYPE_CODE_UNDEF:
 470     case TYPE_CODE_BOOL:
 471     case TYPE_CODE_CHAR:
 472     default:
 473       generic_value_print (val, stream, recurse, options, &m2_decorations);
 474       break;
 475     }
 476 }