gdb/m2-lang.c

   1 /* Modula 2 language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 1992-2021 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 #include "m2-exp.h"
  32
  33 /* A helper function for UNOP_HIGH.  */
  34
  35 struct value *
  36 eval_op_m2_high (struct type *expect_type, struct expression *exp,
  37                  enum noside noside,
  38                  struct value *arg1)
  39 {
  40   if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
  41     return arg1;
  42   else
  43     {
  44       arg1 = coerce_ref (arg1);
  45       struct type *type = check_typedef (value_type (arg1));
  46
  47       if (m2_is_unbounded_array (type))
  48         {
  49           struct value *temp = arg1;
  50
  51           type = type->field (1).type ();
  52           /* i18n: Do not translate the "_m2_high" part!  */
  53           arg1 = value_struct_elt (&temp, NULL, "_m2_high", NULL,
  54                                    _("unbounded structure "
  55                                      "missing _m2_high field"));
  56
  57           if (value_type (arg1) != type)
  58             arg1 = value_cast (type, arg1);
  59         }
  60     }
  61   return arg1;
  62 }
  63
  64 /* A helper function for BINOP_SUBSCRIPT.  */
  65
  66 struct value *
  67 eval_op_m2_subscript (struct type *expect_type, struct expression *exp,
  68                       enum noside noside,
  69                       struct value *arg1, struct value *arg2)
  70 {
  71   if (noside == EVAL_SKIP)
  72     return eval_skip_value (exp);
  73   /* If the user attempts to subscript something that is not an
  74      array or pointer type (like a plain int variable for example),
  75      then report this as an error.  */
  76
  77   arg1 = coerce_ref (arg1);
  78   struct type *type = check_typedef (value_type (arg1));
  79
  80   if (m2_is_unbounded_array (type))
  81     {
  82       struct value *temp = arg1;
  83       type = type->field (0).type ();
  84       if (type == NULL || (type->code () != TYPE_CODE_PTR))
  85         error (_("internal error: unbounded "
  86                  "array structure is unknown"));
  87       /* i18n: Do not translate the "_m2_contents" part!  */
  88       arg1 = value_struct_elt (&temp, NULL, "_m2_contents", NULL,
  89                                _("unbounded structure "
  90                                  "missing _m2_contents field"));
  91
  92       if (value_type (arg1) != type)
  93         arg1 = value_cast (type, arg1);
  94
  95       check_typedef (value_type (arg1));
  96       return value_ind (value_ptradd (arg1, value_as_long (arg2)));
  97     }
  98   else
  99     if (type->code () != TYPE_CODE_ARRAY)
 100       {
 101         if (type->name ())
 102           error (_("cannot subscript something of type `%s'"),
 103                  type->name ());
 104         else
 105           error (_("cannot subscript requested type"));
 106       }
 107
 108   if (noside == EVAL_AVOID_SIDE_EFFECTS)
 109     return value_zero (TYPE_TARGET_TYPE (type), VALUE_LVAL (arg1));
 110   else
 111     return value_subscript (arg1, value_as_long (arg2));
 112 }
 113
 114 static struct value *
 115 evaluate_subexp_modula2 (struct type *expect_type, struct expression *exp,
 116                          int *pos, enum noside noside)
 117 {
 118   enum exp_opcode op = exp->elts[*pos].opcode;
 119   struct value *arg1;
 120   struct value *arg2;
 121
 122   switch (op)
 123     {
 124     case UNOP_HIGH:
 125       (*pos)++;
 126       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
 127       return eval_op_m2_high (expect_type, exp, noside, arg1);
 128
 129     case BINOP_SUBSCRIPT:
 130       (*pos)++;
 131       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
 132       arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
 133       return eval_op_m2_subscript (expect_type, exp, noside, arg1, arg2);
 134
 135     default:
 136       return evaluate_subexp_standard (expect_type, exp, pos, noside);
 137     }
 138 }
 139 \f
 140
 141 /* Table of operators and their precedences for printing expressions.  */
 142
 143 const struct op_print m2_language::op_print_tab[] =
 144 {
 145   {"+", BINOP_ADD, PREC_ADD, 0},
 146   {"+", UNOP_PLUS, PREC_PREFIX, 0},
 147   {"-", BINOP_SUB, PREC_ADD, 0},
 148   {"-", UNOP_NEG, PREC_PREFIX, 0},
 149   {"*", BINOP_MUL, PREC_MUL, 0},
 150   {"/", BINOP_DIV, PREC_MUL, 0},
 151   {"DIV", BINOP_INTDIV, PREC_MUL, 0},
 152   {"MOD", BINOP_REM, PREC_MUL, 0},
 153   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 154   {"OR", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
 155   {"AND", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
 156   {"NOT", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 157   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 158   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 159   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 160   {">=", BINOP_GEQ, PREC_ORDER, 0},
 161   {">", BINOP_GTR, PREC_ORDER, 0},
 162   {"<", BINOP_LESS, PREC_ORDER, 0},
 163   {"^", UNOP_IND, PREC_PREFIX, 0},
 164   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 165   {"CAP", UNOP_CAP, PREC_BUILTIN_FUNCTION, 0},
 166   {"CHR", UNOP_CHR, PREC_BUILTIN_FUNCTION, 0},
 167   {"ORD", UNOP_ORD, PREC_BUILTIN_FUNCTION, 0},
 168   {"FLOAT", UNOP_FLOAT, PREC_BUILTIN_FUNCTION, 0},
 169   {"HIGH", UNOP_HIGH, PREC_BUILTIN_FUNCTION, 0},
 170   {"MAX", UNOP_MAX, PREC_BUILTIN_FUNCTION, 0},
 171   {"MIN", UNOP_MIN, PREC_BUILTIN_FUNCTION, 0},
 172   {"ODD", UNOP_ODD, PREC_BUILTIN_FUNCTION, 0},
 173   {"TRUNC", UNOP_TRUNC, PREC_BUILTIN_FUNCTION, 0},
 174   {NULL, OP_NULL, PREC_BUILTIN_FUNCTION, 0}
 175 };
 176 \f
 177
 178 const struct exp_descriptor m2_language::exp_descriptor_modula2 =
 179 {
 180   print_subexp_standard,
 181   operator_length_standard,
 182   operator_check_standard,
 183   dump_subexp_body_standard,
 184   evaluate_subexp_modula2
 185 };
 186
 187 /* Single instance of the M2 language.  */
 188
 189 static m2_language m2_language_defn;
 190
 191 /* See language.h.  */
 192
 193 void
 194 m2_language::language_arch_info (struct gdbarch *gdbarch,
 195                                  struct language_arch_info *lai) const
 196 {
 197   const struct builtin_m2_type *builtin = builtin_m2_type (gdbarch);
 198
 199   /* Helper function to allow shorter lines below.  */
 200   auto add  = [&] (struct type * t)
 201   {
 202     lai->add_primitive_type (t);
 203   };
 204
 205   add (builtin->builtin_char);
 206   add (builtin->builtin_int);
 207   add (builtin->builtin_card);
 208   add (builtin->builtin_real);
 209   add (builtin->builtin_bool);
 210
 211   lai->set_string_char_type (builtin->builtin_char);
 212   lai->set_bool_type (builtin->builtin_bool, "BOOLEAN");
 213 }
 214
 215 /* See languge.h.  */
 216
 217 void
 218 m2_language::printchar (int c, struct type *type,
 219                         struct ui_file *stream) const
 220 {
 221   fputs_filtered ("'", stream);
 222   emitchar (c, type, stream, '\'');
 223   fputs_filtered ("'", stream);
 224 }
 225
 226 /* See language.h.  */
 227
 228 void
 229 m2_language::printstr (struct ui_file *stream, struct type *elttype,
 230                         const gdb_byte *string, unsigned int length,
 231                         const char *encoding, int force_ellipses,
 232                         const struct value_print_options *options) const
 233 {
 234   unsigned int i;
 235   unsigned int things_printed = 0;
 236   int in_quotes = 0;
 237   int need_comma = 0;
 238
 239   if (length == 0)
 240     {
 241       fputs_filtered ("\"\"", gdb_stdout);
 242       return;
 243     }
 244
 245   for (i = 0; i < length && things_printed < options->print_max; ++i)
 246     {
 247       /* Position of the character we are examining
 248          to see whether it is repeated.  */
 249       unsigned int rep1;
 250       /* Number of repetitions we have detected so far.  */
 251       unsigned int reps;
 252
 253       QUIT;
 254
 255       if (need_comma)
 256         {
 257           fputs_filtered (", ", stream);
 258           need_comma = 0;
 259         }
 260
 261       rep1 = i + 1;
 262       reps = 1;
 263       while (rep1 < length && string[rep1] == string[i])
 264         {
 265           ++rep1;
 266           ++reps;
 267         }
 268
 269       if (reps > options->repeat_count_threshold)
 270         {
 271           if (in_quotes)
 272             {
 273               fputs_filtered ("\", ", stream);
 274               in_quotes = 0;
 275             }
 276           printchar (string[i], elttype, stream);
 277           fprintf_filtered (stream, " <repeats %u times>", reps);
 278           i = rep1 - 1;
 279           things_printed += options->repeat_count_threshold;
 280           need_comma = 1;
 281         }
 282       else
 283         {
 284           if (!in_quotes)
 285             {
 286               fputs_filtered ("\"", stream);
 287               in_quotes = 1;
 288             }
 289           emitchar (string[i], elttype, stream, '"');
 290           ++things_printed;
 291         }
 292     }
 293
 294   /* Terminate the quotes if necessary.  */
 295   if (in_quotes)
 296     fputs_filtered ("\"", stream);
 297
 298   if (force_ellipses || i < length)
 299     fputs_filtered ("...", stream);
 300 }
 301
 302 /* See language.h.  */
 303
 304 void
 305 m2_language::emitchar (int ch, struct type *chtype,
 306                        struct ui_file *stream, int quoter) const
 307 {
 308   ch &= 0xFF;                   /* Avoid sign bit follies.  */
 309
 310   if (PRINT_LITERAL_FORM (ch))
 311     {
 312       if (ch == '\\' || ch == quoter)
 313         fputs_filtered ("\\", stream);
 314       fprintf_filtered (stream, "%c", ch);
 315     }
 316   else
 317     {
 318       switch (ch)
 319         {
 320         case '\n':
 321           fputs_filtered ("\\n", stream);
 322           break;
 323         case '\b':
 324           fputs_filtered ("\\b", stream);
 325           break;
 326         case '\t':
 327           fputs_filtered ("\\t", stream);
 328           break;
 329         case '\f':
 330           fputs_filtered ("\\f", stream);
 331           break;
 332         case '\r':
 333           fputs_filtered ("\\r", stream);
 334           break;
 335         case '\033':
 336           fputs_filtered ("\\e", stream);
 337           break;
 338         case '\007':
 339           fputs_filtered ("\\a", stream);
 340           break;
 341         default:
 342           fprintf_filtered (stream, "\\%.3o", (unsigned int) ch);
 343           break;
 344         }
 345     }
 346 }
 347
 348 /* Called during architecture gdbarch initialisation to create language
 349    specific types.  */
 350
 351 static void *
 352 build_m2_types (struct gdbarch *gdbarch)
 353 {
 354   struct builtin_m2_type *builtin_m2_type
 355     = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct builtin_m2_type);
 356
 357   /* Modula-2 "pervasive" types.  NOTE:  these can be redefined!!! */
 358   builtin_m2_type->builtin_int
 359     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 0, "INTEGER");
 360   builtin_m2_type->builtin_card
 361     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "CARDINAL");
 362   builtin_m2_type->builtin_real
 363     = arch_float_type (gdbarch, gdbarch_float_bit (gdbarch), "REAL",
 364                        gdbarch_float_format (gdbarch));
 365   builtin_m2_type->builtin_char
 366     = arch_character_type (gdbarch, TARGET_CHAR_BIT, 1, "CHAR");
 367   builtin_m2_type->builtin_bool
 368     = arch_boolean_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "BOOLEAN");
 369
 370   return builtin_m2_type;
 371 }
 372
 373 static struct gdbarch_data *m2_type_data;
 374
 375 const struct builtin_m2_type *
 376 builtin_m2_type (struct gdbarch *gdbarch)
 377 {
 378   return (const struct builtin_m2_type *) gdbarch_data (gdbarch, m2_type_data);
 379 }
 380
 381
 382 /* Initialization for Modula-2 */
 383
 384 void _initialize_m2_language ();
 385 void
 386 _initialize_m2_language ()
 387 {
 388   m2_type_data = gdbarch_data_register_post_init (build_m2_types);
 389 }