gdb/m2-lang.c

   1 /* Modula 2 language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 1992-2020 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 "parser-defs.h"
  25 #include "language.h"
  26 #include "varobj.h"
  27 #include "m2-lang.h"
  28 #include "c-lang.h"
  29 #include "valprint.h"
  30 #include "gdbarch.h"
  31
  32 static struct value *
  33 evaluate_subexp_modula2 (struct type *expect_type, struct expression *exp,
  34                          int *pos, enum noside noside)
  35 {
  36   enum exp_opcode op = exp->elts[*pos].opcode;
  37   struct value *arg1;
  38   struct value *arg2;
  39   struct type *type;
  40
  41   switch (op)
  42     {
  43     case UNOP_HIGH:
  44       (*pos)++;
  45       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
  46
  47       if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
  48         return arg1;
  49       else
  50         {
  51           arg1 = coerce_ref (arg1);
  52           type = check_typedef (value_type (arg1));
  53
  54           if (m2_is_unbounded_array (type))
  55             {
  56               struct value *temp = arg1;
  57
  58               type = type->field (1).type ();
  59               /* i18n: Do not translate the "_m2_high" part!  */
  60               arg1 = value_struct_elt (&temp, NULL, "_m2_high", NULL,
  61                                        _("unbounded structure "
  62                                          "missing _m2_high field"));
  63
  64               if (value_type (arg1) != type)
  65                 arg1 = value_cast (type, arg1);
  66             }
  67         }
  68       return arg1;
  69
  70     case BINOP_SUBSCRIPT:
  71       (*pos)++;
  72       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
  73       arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
  74       if (noside == EVAL_SKIP)
  75         goto nosideret;
  76       /* If the user attempts to subscript something that is not an
  77          array or pointer type (like a plain int variable for example),
  78          then report this as an error.  */
  79
  80       arg1 = coerce_ref (arg1);
  81       type = check_typedef (value_type (arg1));
  82
  83       if (m2_is_unbounded_array (type))
  84         {
  85           struct value *temp = arg1;
  86           type = type->field (0).type ();
  87           if (type == NULL || (type->code () != TYPE_CODE_PTR))
  88             {
  89               warning (_("internal error: unbounded "
  90                          "array structure is unknown"));
  91               return evaluate_subexp_standard (expect_type, exp, pos, noside);
  92             }
  93           /* i18n: Do not translate the "_m2_contents" part!  */
  94           arg1 = value_struct_elt (&temp, NULL, "_m2_contents", NULL,
  95                                    _("unbounded structure "
  96                                      "missing _m2_contents field"));
  97
  98           if (value_type (arg1) != type)
  99             arg1 = value_cast (type, arg1);
 100
 101           check_typedef (value_type (arg1));
 102           return value_ind (value_ptradd (arg1, value_as_long (arg2)));
 103         }
 104       else
 105         if (type->code () != TYPE_CODE_ARRAY)
 106           {
 107             if (type->name ())
 108               error (_("cannot subscript something of type `%s'"),
 109                      type->name ());
 110             else
 111               error (_("cannot subscript requested type"));
 112           }
 113
 114       if (noside == EVAL_AVOID_SIDE_EFFECTS)
 115         return value_zero (TYPE_TARGET_TYPE (type), VALUE_LVAL (arg1));
 116       else
 117         return value_subscript (arg1, value_as_long (arg2));
 118
 119     default:
 120       return evaluate_subexp_standard (expect_type, exp, pos, noside);
 121     }
 122
 123  nosideret:
 124   return value_from_longest (builtin_type (exp->gdbarch)->builtin_int, 1);
 125 }
 126 \f
 127
 128 /* Table of operators and their precedences for printing expressions.  */
 129
 130 const struct op_print m2_language::op_print_tab[] =
 131 {
 132   {"+", BINOP_ADD, PREC_ADD, 0},
 133   {"+", UNOP_PLUS, PREC_PREFIX, 0},
 134   {"-", BINOP_SUB, PREC_ADD, 0},
 135   {"-", UNOP_NEG, PREC_PREFIX, 0},
 136   {"*", BINOP_MUL, PREC_MUL, 0},
 137   {"/", BINOP_DIV, PREC_MUL, 0},
 138   {"DIV", BINOP_INTDIV, PREC_MUL, 0},
 139   {"MOD", BINOP_REM, PREC_MUL, 0},
 140   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 141   {"OR", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
 142   {"AND", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
 143   {"NOT", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 144   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 145   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 146   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 147   {">=", BINOP_GEQ, PREC_ORDER, 0},
 148   {">", BINOP_GTR, PREC_ORDER, 0},
 149   {"<", BINOP_LESS, PREC_ORDER, 0},
 150   {"^", UNOP_IND, PREC_PREFIX, 0},
 151   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 152   {"CAP", UNOP_CAP, PREC_BUILTIN_FUNCTION, 0},
 153   {"CHR", UNOP_CHR, PREC_BUILTIN_FUNCTION, 0},
 154   {"ORD", UNOP_ORD, PREC_BUILTIN_FUNCTION, 0},
 155   {"FLOAT", UNOP_FLOAT, PREC_BUILTIN_FUNCTION, 0},
 156   {"HIGH", UNOP_HIGH, PREC_BUILTIN_FUNCTION, 0},
 157   {"MAX", UNOP_MAX, PREC_BUILTIN_FUNCTION, 0},
 158   {"MIN", UNOP_MIN, PREC_BUILTIN_FUNCTION, 0},
 159   {"ODD", UNOP_ODD, PREC_BUILTIN_FUNCTION, 0},
 160   {"TRUNC", UNOP_TRUNC, PREC_BUILTIN_FUNCTION, 0},
 161   {NULL, OP_NULL, PREC_BUILTIN_FUNCTION, 0}
 162 };
 163 \f
 164
 165 const struct exp_descriptor m2_language::exp_descriptor_modula2 =
 166 {
 167   print_subexp_standard,
 168   operator_length_standard,
 169   operator_check_standard,
 170   dump_subexp_body_standard,
 171   evaluate_subexp_modula2
 172 };
 173
 174 /* Single instance of the M2 language.  */
 175
 176 static m2_language m2_language_defn;
 177
 178 /* See language.h.  */
 179
 180 void
 181 m2_language::language_arch_info (struct gdbarch *gdbarch,
 182                                  struct language_arch_info *lai) const
 183 {
 184   const struct builtin_m2_type *builtin = builtin_m2_type (gdbarch);
 185
 186   /* Helper function to allow shorter lines below.  */
 187   auto add  = [&] (struct type * t)
 188   {
 189     lai->add_primitive_type (t);
 190   };
 191
 192   add (builtin->builtin_char);
 193   add (builtin->builtin_int);
 194   add (builtin->builtin_card);
 195   add (builtin->builtin_real);
 196   add (builtin->builtin_bool);
 197
 198   lai->set_string_char_type (builtin->builtin_char);
 199   lai->set_bool_type (builtin->builtin_bool, "BOOLEAN");
 200 }
 201
 202 /* See languge.h.  */
 203
 204 void
 205 m2_language::printchar (int c, struct type *type,
 206                         struct ui_file *stream) const
 207 {
 208   fputs_filtered ("'", stream);
 209   emitchar (c, type, stream, '\'');
 210   fputs_filtered ("'", stream);
 211 }
 212
 213 /* See language.h.  */
 214
 215 void
 216 m2_language::printstr (struct ui_file *stream, struct type *elttype,
 217                         const gdb_byte *string, unsigned int length,
 218                         const char *encoding, int force_ellipses,
 219                         const struct value_print_options *options) const
 220 {
 221   unsigned int i;
 222   unsigned int things_printed = 0;
 223   int in_quotes = 0;
 224   int need_comma = 0;
 225
 226   if (length == 0)
 227     {
 228       fputs_filtered ("\"\"", gdb_stdout);
 229       return;
 230     }
 231
 232   for (i = 0; i < length && things_printed < options->print_max; ++i)
 233     {
 234       /* Position of the character we are examining
 235          to see whether it is repeated.  */
 236       unsigned int rep1;
 237       /* Number of repetitions we have detected so far.  */
 238       unsigned int reps;
 239
 240       QUIT;
 241
 242       if (need_comma)
 243         {
 244           fputs_filtered (", ", stream);
 245           need_comma = 0;
 246         }
 247
 248       rep1 = i + 1;
 249       reps = 1;
 250       while (rep1 < length && string[rep1] == string[i])
 251         {
 252           ++rep1;
 253           ++reps;
 254         }
 255
 256       if (reps > options->repeat_count_threshold)
 257         {
 258           if (in_quotes)
 259             {
 260               fputs_filtered ("\", ", stream);
 261               in_quotes = 0;
 262             }
 263           printchar (string[i], elttype, stream);
 264           fprintf_filtered (stream, " <repeats %u times>", reps);
 265           i = rep1 - 1;
 266           things_printed += options->repeat_count_threshold;
 267           need_comma = 1;
 268         }
 269       else
 270         {
 271           if (!in_quotes)
 272             {
 273               fputs_filtered ("\"", stream);
 274               in_quotes = 1;
 275             }
 276           emitchar (string[i], elttype, stream, '"');
 277           ++things_printed;
 278         }
 279     }
 280
 281   /* Terminate the quotes if necessary.  */
 282   if (in_quotes)
 283     fputs_filtered ("\"", stream);
 284
 285   if (force_ellipses || i < length)
 286     fputs_filtered ("...", stream);
 287 }
 288
 289 /* See language.h.  */
 290
 291 void
 292 m2_language::emitchar (int ch, struct type *chtype,
 293                        struct ui_file *stream, int quoter) const
 294 {
 295   ch &= 0xFF;                   /* Avoid sign bit follies.  */
 296
 297   if (PRINT_LITERAL_FORM (ch))
 298     {
 299       if (ch == '\\' || ch == quoter)
 300         fputs_filtered ("\\", stream);
 301       fprintf_filtered (stream, "%c", ch);
 302     }
 303   else
 304     {
 305       switch (ch)
 306         {
 307         case '\n':
 308           fputs_filtered ("\\n", stream);
 309           break;
 310         case '\b':
 311           fputs_filtered ("\\b", stream);
 312           break;
 313         case '\t':
 314           fputs_filtered ("\\t", stream);
 315           break;
 316         case '\f':
 317           fputs_filtered ("\\f", stream);
 318           break;
 319         case '\r':
 320           fputs_filtered ("\\r", stream);
 321           break;
 322         case '\033':
 323           fputs_filtered ("\\e", stream);
 324           break;
 325         case '\007':
 326           fputs_filtered ("\\a", stream);
 327           break;
 328         default:
 329           fprintf_filtered (stream, "\\%.3o", (unsigned int) ch);
 330           break;
 331         }
 332     }
 333 }
 334
 335 /* Called during architecture gdbarch initialisation to create language
 336    specific types.  */
 337
 338 static void *
 339 build_m2_types (struct gdbarch *gdbarch)
 340 {
 341   struct builtin_m2_type *builtin_m2_type
 342     = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct builtin_m2_type);
 343
 344   /* Modula-2 "pervasive" types.  NOTE:  these can be redefined!!! */
 345   builtin_m2_type->builtin_int
 346     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 0, "INTEGER");
 347   builtin_m2_type->builtin_card
 348     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "CARDINAL");
 349   builtin_m2_type->builtin_real
 350     = arch_float_type (gdbarch, gdbarch_float_bit (gdbarch), "REAL",
 351                        gdbarch_float_format (gdbarch));
 352   builtin_m2_type->builtin_char
 353     = arch_character_type (gdbarch, TARGET_CHAR_BIT, 1, "CHAR");
 354   builtin_m2_type->builtin_bool
 355     = arch_boolean_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "BOOLEAN");
 356
 357   return builtin_m2_type;
 358 }
 359
 360 static struct gdbarch_data *m2_type_data;
 361
 362 const struct builtin_m2_type *
 363 builtin_m2_type (struct gdbarch *gdbarch)
 364 {
 365   return (const struct builtin_m2_type *) gdbarch_data (gdbarch, m2_type_data);
 366 }
 367
 368
 369 /* Initialization for Modula-2 */
 370
 371 void _initialize_m2_language ();
 372 void
 373 _initialize_m2_language ()
 374 {
 375   m2_type_data = gdbarch_data_register_post_init (build_m2_types);
 376 }