gdb/m2-lang.c

   1 /* Modula 2 language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 1992-2016 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 extern void _initialize_m2_language (void);
  32 static void m2_printchar (int, struct type *, struct ui_file *);
  33 static void m2_emit_char (int, struct type *, struct ui_file *, int);
  34
  35 /* Print the character C on STREAM as part of the contents of a literal
  36    string whose delimiter is QUOTER.  Note that that format for printing
  37    characters and strings is language specific.
  38    FIXME:  This is a copy of the same function from c-exp.y.  It should
  39    be replaced with a true Modula version.  */
  40
  41 static void
  42 m2_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
  43 {
  44
  45   c &= 0xFF;                    /* Avoid sign bit follies.  */
  46
  47   if (PRINT_LITERAL_FORM (c))
  48     {
  49       if (c == '\\' || c == quoter)
  50         {
  51           fputs_filtered ("\\", stream);
  52         }
  53       fprintf_filtered (stream, "%c", c);
  54     }
  55   else
  56     {
  57       switch (c)
  58         {
  59         case '\n':
  60           fputs_filtered ("\\n", stream);
  61           break;
  62         case '\b':
  63           fputs_filtered ("\\b", stream);
  64           break;
  65         case '\t':
  66           fputs_filtered ("\\t", stream);
  67           break;
  68         case '\f':
  69           fputs_filtered ("\\f", stream);
  70           break;
  71         case '\r':
  72           fputs_filtered ("\\r", stream);
  73           break;
  74         case '\033':
  75           fputs_filtered ("\\e", stream);
  76           break;
  77         case '\007':
  78           fputs_filtered ("\\a", stream);
  79           break;
  80         default:
  81           fprintf_filtered (stream, "\\%.3o", (unsigned int) c);
  82           break;
  83         }
  84     }
  85 }
  86
  87 /* FIXME:  This is a copy of the same function from c-exp.y.  It should
  88    be replaced with a true Modula version.  */
  89
  90 static void
  91 m2_printchar (int c, struct type *type, struct ui_file *stream)
  92 {
  93   fputs_filtered ("'", stream);
  94   LA_EMIT_CHAR (c, type, stream, '\'');
  95   fputs_filtered ("'", stream);
  96 }
  97
  98 /* Print the character string STRING, printing at most LENGTH characters.
  99    Printing stops early if the number hits print_max; repeat counts
 100    are printed as appropriate.  Print ellipses at the end if we
 101    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.
 102    FIXME:  This is a copy of the same function from c-exp.y.  It should
 103    be replaced with a true Modula version.  */
 104
 105 static void
 106 m2_printstr (struct ui_file *stream, struct type *type, const gdb_byte *string,
 107              unsigned int length, const char *encoding, int force_ellipses,
 108              const struct value_print_options *options)
 109 {
 110   unsigned int i;
 111   unsigned int things_printed = 0;
 112   int in_quotes = 0;
 113   int need_comma = 0;
 114
 115   if (length == 0)
 116     {
 117       fputs_filtered ("\"\"", gdb_stdout);
 118       return;
 119     }
 120
 121   for (i = 0; i < length && things_printed < options->print_max; ++i)
 122     {
 123       /* Position of the character we are examining
 124          to see whether it is repeated.  */
 125       unsigned int rep1;
 126       /* Number of repetitions we have detected so far.  */
 127       unsigned int reps;
 128
 129       QUIT;
 130
 131       if (need_comma)
 132         {
 133           fputs_filtered (", ", stream);
 134           need_comma = 0;
 135         }
 136
 137       rep1 = i + 1;
 138       reps = 1;
 139       while (rep1 < length && string[rep1] == string[i])
 140         {
 141           ++rep1;
 142           ++reps;
 143         }
 144
 145       if (reps > options->repeat_count_threshold)
 146         {
 147           if (in_quotes)
 148             {
 149               fputs_filtered ("\", ", stream);
 150               in_quotes = 0;
 151             }
 152           m2_printchar (string[i], type, stream);
 153           fprintf_filtered (stream, " <repeats %u times>", reps);
 154           i = rep1 - 1;
 155           things_printed += options->repeat_count_threshold;
 156           need_comma = 1;
 157         }
 158       else
 159         {
 160           if (!in_quotes)
 161             {
 162               fputs_filtered ("\"", stream);
 163               in_quotes = 1;
 164             }
 165           LA_EMIT_CHAR (string[i], type, stream, '"');
 166           ++things_printed;
 167         }
 168     }
 169
 170   /* Terminate the quotes if necessary.  */
 171   if (in_quotes)
 172     fputs_filtered ("\"", stream);
 173
 174   if (force_ellipses || i < length)
 175     fputs_filtered ("...", stream);
 176 }
 177
 178 static struct value *
 179 evaluate_subexp_modula2 (struct type *expect_type, struct expression *exp,
 180                          int *pos, enum noside noside)
 181 {
 182   enum exp_opcode op = exp->elts[*pos].opcode;
 183   struct value *arg1;
 184   struct value *arg2;
 185   struct type *type;
 186
 187   switch (op)
 188     {
 189     case UNOP_HIGH:
 190       (*pos)++;
 191       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
 192
 193       if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
 194         return arg1;
 195       else
 196         {
 197           arg1 = coerce_ref (arg1);
 198           type = check_typedef (value_type (arg1));
 199
 200           if (m2_is_unbounded_array (type))
 201             {
 202               struct value *temp = arg1;
 203
 204               type = TYPE_FIELD_TYPE (type, 1);
 205               /* i18n: Do not translate the "_m2_high" part!  */
 206               arg1 = value_struct_elt (&temp, NULL, "_m2_high", NULL,
 207                                        _("unbounded structure "
 208                                          "missing _m2_high field"));
 209
 210               if (value_type (arg1) != type)
 211                 arg1 = value_cast (type, arg1);
 212             }
 213         }
 214       return arg1;
 215
 216     case BINOP_SUBSCRIPT:
 217       (*pos)++;
 218       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
 219       arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
 220       if (noside == EVAL_SKIP)
 221         goto nosideret;
 222       /* If the user attempts to subscript something that is not an
 223          array or pointer type (like a plain int variable for example),
 224          then report this as an error.  */
 225
 226       arg1 = coerce_ref (arg1);
 227       type = check_typedef (value_type (arg1));
 228
 229       if (m2_is_unbounded_array (type))
 230         {
 231           struct value *temp = arg1;
 232           type = TYPE_FIELD_TYPE (type, 0);
 233           if (type == NULL || (TYPE_CODE (type) != TYPE_CODE_PTR))
 234             {
 235               warning (_("internal error: unbounded "
 236                          "array structure is unknown"));
 237               return evaluate_subexp_standard (expect_type, exp, pos, noside);
 238             }
 239           /* i18n: Do not translate the "_m2_contents" part!  */
 240           arg1 = value_struct_elt (&temp, NULL, "_m2_contents", NULL,
 241                                    _("unbounded structure "
 242                                      "missing _m2_contents field"));
 243
 244           if (value_type (arg1) != type)
 245             arg1 = value_cast (type, arg1);
 246
 247           check_typedef (value_type (arg1));
 248           return value_ind (value_ptradd (arg1, value_as_long (arg2)));
 249         }
 250       else
 251         if (TYPE_CODE (type) != TYPE_CODE_ARRAY)
 252           {
 253             if (TYPE_NAME (type))
 254               error (_("cannot subscript something of type `%s'"),
 255                      TYPE_NAME (type));
 256             else
 257               error (_("cannot subscript requested type"));
 258           }
 259
 260       if (noside == EVAL_AVOID_SIDE_EFFECTS)
 261         return value_zero (TYPE_TARGET_TYPE (type), VALUE_LVAL (arg1));
 262       else
 263         return value_subscript (arg1, value_as_long (arg2));
 264
 265     default:
 266       return evaluate_subexp_standard (expect_type, exp, pos, noside);
 267     }
 268
 269  nosideret:
 270   return value_from_longest (builtin_type (exp->gdbarch)->builtin_int, 1);
 271 }
 272 \f
 273
 274 /* Table of operators and their precedences for printing expressions.  */
 275
 276 static const struct op_print m2_op_print_tab[] =
 277 {
 278   {"+", BINOP_ADD, PREC_ADD, 0},
 279   {"+", UNOP_PLUS, PREC_PREFIX, 0},
 280   {"-", BINOP_SUB, PREC_ADD, 0},
 281   {"-", UNOP_NEG, PREC_PREFIX, 0},
 282   {"*", BINOP_MUL, PREC_MUL, 0},
 283   {"/", BINOP_DIV, PREC_MUL, 0},
 284   {"DIV", BINOP_INTDIV, PREC_MUL, 0},
 285   {"MOD", BINOP_REM, PREC_MUL, 0},
 286   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 287   {"OR", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
 288   {"AND", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
 289   {"NOT", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 290   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 291   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 292   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 293   {">=", BINOP_GEQ, PREC_ORDER, 0},
 294   {">", BINOP_GTR, PREC_ORDER, 0},
 295   {"<", BINOP_LESS, PREC_ORDER, 0},
 296   {"^", UNOP_IND, PREC_PREFIX, 0},
 297   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 298   {"CAP", UNOP_CAP, PREC_BUILTIN_FUNCTION, 0},
 299   {"CHR", UNOP_CHR, PREC_BUILTIN_FUNCTION, 0},
 300   {"ORD", UNOP_ORD, PREC_BUILTIN_FUNCTION, 0},
 301   {"FLOAT", UNOP_FLOAT, PREC_BUILTIN_FUNCTION, 0},
 302   {"HIGH", UNOP_HIGH, PREC_BUILTIN_FUNCTION, 0},
 303   {"MAX", UNOP_MAX, PREC_BUILTIN_FUNCTION, 0},
 304   {"MIN", UNOP_MIN, PREC_BUILTIN_FUNCTION, 0},
 305   {"ODD", UNOP_ODD, PREC_BUILTIN_FUNCTION, 0},
 306   {"TRUNC", UNOP_TRUNC, PREC_BUILTIN_FUNCTION, 0},
 307   {NULL, OP_NULL, PREC_BUILTIN_FUNCTION, 0}
 308 };
 309 \f
 310 /* The built-in types of Modula-2.  */
 311
 312 enum m2_primitive_types {
 313   m2_primitive_type_char,
 314   m2_primitive_type_int,
 315   m2_primitive_type_card,
 316   m2_primitive_type_real,
 317   m2_primitive_type_bool,
 318   nr_m2_primitive_types
 319 };
 320
 321 static void
 322 m2_language_arch_info (struct gdbarch *gdbarch,
 323                        struct language_arch_info *lai)
 324 {
 325   const struct builtin_m2_type *builtin = builtin_m2_type (gdbarch);
 326
 327   lai->string_char_type = builtin->builtin_char;
 328   lai->primitive_type_vector
 329     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_m2_primitive_types + 1,
 330                               struct type *);
 331
 332   lai->primitive_type_vector [m2_primitive_type_char]
 333     = builtin->builtin_char;
 334   lai->primitive_type_vector [m2_primitive_type_int]
 335     = builtin->builtin_int;
 336   lai->primitive_type_vector [m2_primitive_type_card]
 337     = builtin->builtin_card;
 338   lai->primitive_type_vector [m2_primitive_type_real]
 339     = builtin->builtin_real;
 340   lai->primitive_type_vector [m2_primitive_type_bool]
 341     = builtin->builtin_bool;
 342
 343   lai->bool_type_symbol = "BOOLEAN";
 344   lai->bool_type_default = builtin->builtin_bool;
 345 }
 346
 347 const struct exp_descriptor exp_descriptor_modula2 =
 348 {
 349   print_subexp_standard,
 350   operator_length_standard,
 351   operator_check_standard,
 352   op_name_standard,
 353   dump_subexp_body_standard,
 354   evaluate_subexp_modula2
 355 };
 356
 357 const struct language_defn m2_language_defn =
 358 {
 359   "modula-2",
 360   "Modula-2",
 361   language_m2,
 362   range_check_on,
 363   case_sensitive_on,
 364   array_row_major,
 365   macro_expansion_no,
 366   NULL,
 367   &exp_descriptor_modula2,
 368   m2_parse,                     /* parser */
 369   m2_yyerror,                   /* parser error function */
 370   null_post_parser,
 371   m2_printchar,                 /* Print character constant */
 372   m2_printstr,                  /* function to print string constant */
 373   m2_emit_char,                 /* Function to print a single character */
 374   m2_print_type,                /* Print a type using appropriate syntax */
 375   m2_print_typedef,             /* Print a typedef using appropriate syntax */
 376   m2_val_print,                 /* Print a value using appropriate syntax */
 377   c_value_print,                /* Print a top-level value */
 378   default_read_var_value,       /* la_read_var_value */
 379   NULL,                         /* Language specific skip_trampoline */
 380   NULL,                         /* name_of_this */
 381   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 382   basic_lookup_transparent_type,/* lookup_transparent_type */
 383   NULL,                         /* Language specific symbol demangler */
 384   NULL,
 385   NULL,                         /* Language specific
 386                                    class_name_from_physname */
 387   m2_op_print_tab,              /* expression operators for printing */
 388   0,                            /* arrays are first-class (not c-style) */
 389   0,                            /* String lower bound */
 390   default_word_break_characters,
 391   default_make_symbol_completion_list,
 392   m2_language_arch_info,
 393   default_print_array_index,
 394   default_pass_by_reference,
 395   default_get_string,
 396   NULL,                         /* la_get_symbol_name_cmp */
 397   iterate_over_symbols,
 398   &default_varobj_ops,
 399   NULL,
 400   NULL,
 401   LANG_MAGIC
 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", NULL);
 417   builtin_m2_type->builtin_char
 418     = arch_character_type (gdbarch, TARGET_CHAR_BIT, 1, "CHAR");
 419   builtin_m2_type->builtin_bool
 420     = arch_boolean_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "BOOLEAN");
 421
 422   return builtin_m2_type;
 423 }
 424
 425 static struct gdbarch_data *m2_type_data;
 426
 427 const struct builtin_m2_type *
 428 builtin_m2_type (struct gdbarch *gdbarch)
 429 {
 430   return (const struct builtin_m2_type *) gdbarch_data (gdbarch, m2_type_data);
 431 }
 432
 433
 434 /* Initialization for Modula-2 */
 435
 436 void
 437 _initialize_m2_language (void)
 438 {
 439   m2_type_data = gdbarch_data_register_post_init (build_m2_types);
 440
 441   add_language (&m2_language_defn);
 442 }