gdb/m2-lang.c

   1 /* Modula 2 language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 1992-2019 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
  31 static void m2_printchar (int, struct type *, struct ui_file *);
  32 static void m2_emit_char (int, struct type *, struct ui_file *, int);
  33
  34 /* Print the character C on STREAM as part of the contents of a literal
  35    string whose delimiter is QUOTER.  Note that that format for printing
  36    characters and strings is language specific.
  37    FIXME:  This is a copy of the same function from c-exp.y.  It should
  38    be replaced with a true Modula version.  */
  39
  40 static void
  41 m2_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
  42 {
  43
  44   c &= 0xFF;                    /* Avoid sign bit follies.  */
  45
  46   if (PRINT_LITERAL_FORM (c))
  47     {
  48       if (c == '\\' || c == quoter)
  49         {
  50           fputs_filtered ("\\", stream);
  51         }
  52       fprintf_filtered (stream, "%c", c);
  53     }
  54   else
  55     {
  56       switch (c)
  57         {
  58         case '\n':
  59           fputs_filtered ("\\n", stream);
  60           break;
  61         case '\b':
  62           fputs_filtered ("\\b", stream);
  63           break;
  64         case '\t':
  65           fputs_filtered ("\\t", stream);
  66           break;
  67         case '\f':
  68           fputs_filtered ("\\f", stream);
  69           break;
  70         case '\r':
  71           fputs_filtered ("\\r", stream);
  72           break;
  73         case '\033':
  74           fputs_filtered ("\\e", stream);
  75           break;
  76         case '\007':
  77           fputs_filtered ("\\a", stream);
  78           break;
  79         default:
  80           fprintf_filtered (stream, "\\%.3o", (unsigned int) c);
  81           break;
  82         }
  83     }
  84 }
  85
  86 /* FIXME:  This is a copy of the same function from c-exp.y.  It should
  87    be replaced with a true Modula version.  */
  88
  89 static void
  90 m2_printchar (int c, struct type *type, struct ui_file *stream)
  91 {
  92   fputs_filtered ("'", stream);
  93   LA_EMIT_CHAR (c, type, stream, '\'');
  94   fputs_filtered ("'", stream);
  95 }
  96
  97 /* Print the character string STRING, printing at most LENGTH characters.
  98    Printing stops early if the number hits print_max; repeat counts
  99    are printed as appropriate.  Print ellipses at the end if we
 100    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.
 101    FIXME:  This is a copy of the same function from c-exp.y.  It should
 102    be replaced with a true Modula version.  */
 103
 104 static void
 105 m2_printstr (struct ui_file *stream, struct type *type, const gdb_byte *string,
 106              unsigned int length, const char *encoding, int force_ellipses,
 107              const struct value_print_options *options)
 108 {
 109   unsigned int i;
 110   unsigned int things_printed = 0;
 111   int in_quotes = 0;
 112   int need_comma = 0;
 113
 114   if (length == 0)
 115     {
 116       fputs_filtered ("\"\"", gdb_stdout);
 117       return;
 118     }
 119
 120   for (i = 0; i < length && things_printed < options->print_max; ++i)
 121     {
 122       /* Position of the character we are examining
 123          to see whether it is repeated.  */
 124       unsigned int rep1;
 125       /* Number of repetitions we have detected so far.  */
 126       unsigned int reps;
 127
 128       QUIT;
 129
 130       if (need_comma)
 131         {
 132           fputs_filtered (", ", stream);
 133           need_comma = 0;
 134         }
 135
 136       rep1 = i + 1;
 137       reps = 1;
 138       while (rep1 < length && string[rep1] == string[i])
 139         {
 140           ++rep1;
 141           ++reps;
 142         }
 143
 144       if (reps > options->repeat_count_threshold)
 145         {
 146           if (in_quotes)
 147             {
 148               fputs_filtered ("\", ", stream);
 149               in_quotes = 0;
 150             }
 151           m2_printchar (string[i], type, stream);
 152           fprintf_filtered (stream, " <repeats %u times>", reps);
 153           i = rep1 - 1;
 154           things_printed += options->repeat_count_threshold;
 155           need_comma = 1;
 156         }
 157       else
 158         {
 159           if (!in_quotes)
 160             {
 161               fputs_filtered ("\"", stream);
 162               in_quotes = 1;
 163             }
 164           LA_EMIT_CHAR (string[i], type, stream, '"');
 165           ++things_printed;
 166         }
 167     }
 168
 169   /* Terminate the quotes if necessary.  */
 170   if (in_quotes)
 171     fputs_filtered ("\"", stream);
 172
 173   if (force_ellipses || i < length)
 174     fputs_filtered ("...", stream);
 175 }
 176
 177 static struct value *
 178 evaluate_subexp_modula2 (struct type *expect_type, struct expression *exp,
 179                          int *pos, enum noside noside)
 180 {
 181   enum exp_opcode op = exp->elts[*pos].opcode;
 182   struct value *arg1;
 183   struct value *arg2;
 184   struct type *type;
 185
 186   switch (op)
 187     {
 188     case UNOP_HIGH:
 189       (*pos)++;
 190       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
 191
 192       if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
 193         return arg1;
 194       else
 195         {
 196           arg1 = coerce_ref (arg1);
 197           type = check_typedef (value_type (arg1));
 198
 199           if (m2_is_unbounded_array (type))
 200             {
 201               struct value *temp = arg1;
 202
 203               type = TYPE_FIELD_TYPE (type, 1);
 204               /* i18n: Do not translate the "_m2_high" part!  */
 205               arg1 = value_struct_elt (&temp, NULL, "_m2_high", NULL,
 206                                        _("unbounded structure "
 207                                          "missing _m2_high field"));
 208
 209               if (value_type (arg1) != type)
 210                 arg1 = value_cast (type, arg1);
 211             }
 212         }
 213       return arg1;
 214
 215     case BINOP_SUBSCRIPT:
 216       (*pos)++;
 217       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
 218       arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
 219       if (noside == EVAL_SKIP)
 220         goto nosideret;
 221       /* If the user attempts to subscript something that is not an
 222          array or pointer type (like a plain int variable for example),
 223          then report this as an error.  */
 224
 225       arg1 = coerce_ref (arg1);
 226       type = check_typedef (value_type (arg1));
 227
 228       if (m2_is_unbounded_array (type))
 229         {
 230           struct value *temp = arg1;
 231           type = TYPE_FIELD_TYPE (type, 0);
 232           if (type == NULL || (TYPE_CODE (type) != TYPE_CODE_PTR))
 233             {
 234               warning (_("internal error: unbounded "
 235                          "array structure is unknown"));
 236               return evaluate_subexp_standard (expect_type, exp, pos, noside);
 237             }
 238           /* i18n: Do not translate the "_m2_contents" part!  */
 239           arg1 = value_struct_elt (&temp, NULL, "_m2_contents", NULL,
 240                                    _("unbounded structure "
 241                                      "missing _m2_contents field"));
 242
 243           if (value_type (arg1) != type)
 244             arg1 = value_cast (type, arg1);
 245
 246           check_typedef (value_type (arg1));
 247           return value_ind (value_ptradd (arg1, value_as_long (arg2)));
 248         }
 249       else
 250         if (TYPE_CODE (type) != TYPE_CODE_ARRAY)
 251           {
 252             if (TYPE_NAME (type))
 253               error (_("cannot subscript something of type `%s'"),
 254                      TYPE_NAME (type));
 255             else
 256               error (_("cannot subscript requested type"));
 257           }
 258
 259       if (noside == EVAL_AVOID_SIDE_EFFECTS)
 260         return value_zero (TYPE_TARGET_TYPE (type), VALUE_LVAL (arg1));
 261       else
 262         return value_subscript (arg1, value_as_long (arg2));
 263
 264     default:
 265       return evaluate_subexp_standard (expect_type, exp, pos, noside);
 266     }
 267
 268  nosideret:
 269   return value_from_longest (builtin_type (exp->gdbarch)->builtin_int, 1);
 270 }
 271 \f
 272
 273 /* Table of operators and their precedences for printing expressions.  */
 274
 275 static const struct op_print m2_op_print_tab[] =
 276 {
 277   {"+", BINOP_ADD, PREC_ADD, 0},
 278   {"+", UNOP_PLUS, PREC_PREFIX, 0},
 279   {"-", BINOP_SUB, PREC_ADD, 0},
 280   {"-", UNOP_NEG, PREC_PREFIX, 0},
 281   {"*", BINOP_MUL, PREC_MUL, 0},
 282   {"/", BINOP_DIV, PREC_MUL, 0},
 283   {"DIV", BINOP_INTDIV, PREC_MUL, 0},
 284   {"MOD", BINOP_REM, PREC_MUL, 0},
 285   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 286   {"OR", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
 287   {"AND", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
 288   {"NOT", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 289   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 290   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 291   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 292   {">=", BINOP_GEQ, PREC_ORDER, 0},
 293   {">", BINOP_GTR, PREC_ORDER, 0},
 294   {"<", BINOP_LESS, PREC_ORDER, 0},
 295   {"^", UNOP_IND, PREC_PREFIX, 0},
 296   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 297   {"CAP", UNOP_CAP, PREC_BUILTIN_FUNCTION, 0},
 298   {"CHR", UNOP_CHR, PREC_BUILTIN_FUNCTION, 0},
 299   {"ORD", UNOP_ORD, PREC_BUILTIN_FUNCTION, 0},
 300   {"FLOAT", UNOP_FLOAT, PREC_BUILTIN_FUNCTION, 0},
 301   {"HIGH", UNOP_HIGH, PREC_BUILTIN_FUNCTION, 0},
 302   {"MAX", UNOP_MAX, PREC_BUILTIN_FUNCTION, 0},
 303   {"MIN", UNOP_MIN, PREC_BUILTIN_FUNCTION, 0},
 304   {"ODD", UNOP_ODD, PREC_BUILTIN_FUNCTION, 0},
 305   {"TRUNC", UNOP_TRUNC, PREC_BUILTIN_FUNCTION, 0},
 306   {NULL, OP_NULL, PREC_BUILTIN_FUNCTION, 0}
 307 };
 308 \f
 309 /* The built-in types of Modula-2.  */
 310
 311 enum m2_primitive_types {
 312   m2_primitive_type_char,
 313   m2_primitive_type_int,
 314   m2_primitive_type_card,
 315   m2_primitive_type_real,
 316   m2_primitive_type_bool,
 317   nr_m2_primitive_types
 318 };
 319
 320 static void
 321 m2_language_arch_info (struct gdbarch *gdbarch,
 322                        struct language_arch_info *lai)
 323 {
 324   const struct builtin_m2_type *builtin = builtin_m2_type (gdbarch);
 325
 326   lai->string_char_type = builtin->builtin_char;
 327   lai->primitive_type_vector
 328     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_m2_primitive_types + 1,
 329                               struct type *);
 330
 331   lai->primitive_type_vector [m2_primitive_type_char]
 332     = builtin->builtin_char;
 333   lai->primitive_type_vector [m2_primitive_type_int]
 334     = builtin->builtin_int;
 335   lai->primitive_type_vector [m2_primitive_type_card]
 336     = builtin->builtin_card;
 337   lai->primitive_type_vector [m2_primitive_type_real]
 338     = builtin->builtin_real;
 339   lai->primitive_type_vector [m2_primitive_type_bool]
 340     = builtin->builtin_bool;
 341
 342   lai->bool_type_symbol = "BOOLEAN";
 343   lai->bool_type_default = builtin->builtin_bool;
 344 }
 345
 346 const struct exp_descriptor exp_descriptor_modula2 =
 347 {
 348   print_subexp_standard,
 349   operator_length_standard,
 350   operator_check_standard,
 351   op_name_standard,
 352   dump_subexp_body_standard,
 353   evaluate_subexp_modula2
 354 };
 355
 356 extern const struct language_defn m2_language_defn =
 357 {
 358   "modula-2",
 359   "Modula-2",
 360   language_m2,
 361   range_check_on,
 362   case_sensitive_on,
 363   array_row_major,
 364   macro_expansion_no,
 365   NULL,
 366   &exp_descriptor_modula2,
 367   m2_parse,                     /* parser */
 368   null_post_parser,
 369   m2_printchar,                 /* Print character constant */
 370   m2_printstr,                  /* function to print string constant */
 371   m2_emit_char,                 /* Function to print a single character */
 372   m2_print_type,                /* Print a type using appropriate syntax */
 373   m2_print_typedef,             /* Print a typedef using appropriate syntax */
 374   m2_val_print,                 /* Print a value using appropriate syntax */
 375   c_value_print,                /* Print a top-level value */
 376   default_read_var_value,       /* la_read_var_value */
 377   NULL,                         /* Language specific skip_trampoline */
 378   NULL,                         /* name_of_this */
 379   false,                        /* la_store_sym_names_in_linkage_form_p */
 380   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 381   basic_lookup_transparent_type,/* lookup_transparent_type */
 382   NULL,                         /* Language specific symbol demangler */
 383   NULL,
 384   NULL,                         /* Language specific
 385                                    class_name_from_physname */
 386   m2_op_print_tab,              /* expression operators for printing */
 387   0,                            /* arrays are first-class (not c-style) */
 388   0,                            /* String lower bound */
 389   default_word_break_characters,
 390   default_collect_symbol_completion_matches,
 391   m2_language_arch_info,
 392   default_print_array_index,
 393   default_pass_by_reference,
 394   default_get_string,
 395   c_watch_location_expression,
 396   NULL,                         /* la_get_symbol_name_matcher */
 397   iterate_over_symbols,
 398   default_search_name_hash,
 399   &default_varobj_ops,
 400   NULL,
 401   NULL
 402 };
 403
 404 static void *
 405 build_m2_types (struct gdbarch *gdbarch)
 406 {
 407   struct builtin_m2_type *builtin_m2_type
 408     = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct builtin_m2_type);
 409
 410   /* Modula-2 "pervasive" types.  NOTE:  these can be redefined!!! */
 411   builtin_m2_type->builtin_int
 412     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 0, "INTEGER");
 413   builtin_m2_type->builtin_card
 414     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "CARDINAL");
 415   builtin_m2_type->builtin_real
 416     = arch_float_type (gdbarch, gdbarch_float_bit (gdbarch), "REAL",
 417                        gdbarch_float_format (gdbarch));
 418   builtin_m2_type->builtin_char
 419     = arch_character_type (gdbarch, TARGET_CHAR_BIT, 1, "CHAR");
 420   builtin_m2_type->builtin_bool
 421     = arch_boolean_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "BOOLEAN");
 422
 423   return builtin_m2_type;
 424 }
 425
 426 static struct gdbarch_data *m2_type_data;
 427
 428 const struct builtin_m2_type *
 429 builtin_m2_type (struct gdbarch *gdbarch)
 430 {
 431   return (const struct builtin_m2_type *) gdbarch_data (gdbarch, m2_type_data);
 432 }
 433
 434
 435 /* Initialization for Modula-2 */
 436
 437 void
 438 _initialize_m2_language (void)
 439 {
 440   m2_type_data = gdbarch_data_register_post_init (build_m2_types);
 441 }