gdb/m2-lang.c

   1 /* Modula 2 language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 1992-1996, 1998, 2000, 2002-2005, 2007-2012 Free
   4    Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "symtab.h"
  23 #include "gdbtypes.h"
  24 #include "expression.h"
  25 #include "parser-defs.h"
  26 #include "language.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               if (options->inspect_it)
 150                 fputs_filtered ("\\\", ", stream);
 151               else
 152                 fputs_filtered ("\", ", stream);
 153               in_quotes = 0;
 154             }
 155           m2_printchar (string[i], type, stream);
 156           fprintf_filtered (stream, " <repeats %u times>", reps);
 157           i = rep1 - 1;
 158           things_printed += options->repeat_count_threshold;
 159           need_comma = 1;
 160         }
 161       else
 162         {
 163           if (!in_quotes)
 164             {
 165               if (options->inspect_it)
 166                 fputs_filtered ("\\\"", stream);
 167               else
 168                 fputs_filtered ("\"", stream);
 169               in_quotes = 1;
 170             }
 171           LA_EMIT_CHAR (string[i], type, stream, '"');
 172           ++things_printed;
 173         }
 174     }
 175
 176   /* Terminate the quotes if necessary.  */
 177   if (in_quotes)
 178     {
 179       if (options->inspect_it)
 180         fputs_filtered ("\\\"", stream);
 181       else
 182         fputs_filtered ("\"", stream);
 183     }
 184
 185   if (force_ellipses || i < length)
 186     fputs_filtered ("...", stream);
 187 }
 188
 189 static struct value *
 190 evaluate_subexp_modula2 (struct type *expect_type, struct expression *exp,
 191                          int *pos, enum noside noside)
 192 {
 193   enum exp_opcode op = exp->elts[*pos].opcode;
 194   struct value *arg1;
 195   struct value *arg2;
 196   struct type *type;
 197
 198   switch (op)
 199     {
 200     case UNOP_HIGH:
 201       (*pos)++;
 202       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
 203
 204       if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
 205         return arg1;
 206       else
 207         {
 208           arg1 = coerce_ref (arg1);
 209           type = check_typedef (value_type (arg1));
 210
 211           if (m2_is_unbounded_array (type))
 212             {
 213               struct value *temp = arg1;
 214
 215               type = TYPE_FIELD_TYPE (type, 1);
 216               /* i18n: Do not translate the "_m2_high" part!  */
 217               arg1 = value_struct_elt (&temp, NULL, "_m2_high", NULL,
 218                                        _("unbounded structure "
 219                                          "missing _m2_high field"));
 220
 221               if (value_type (arg1) != type)
 222                 arg1 = value_cast (type, arg1);
 223             }
 224         }
 225       return arg1;
 226
 227     case BINOP_SUBSCRIPT:
 228       (*pos)++;
 229       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
 230       arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
 231       if (noside == EVAL_SKIP)
 232         goto nosideret;
 233       /* If the user attempts to subscript something that is not an
 234          array or pointer type (like a plain int variable for example),
 235          then report this as an error.  */
 236
 237       arg1 = coerce_ref (arg1);
 238       type = check_typedef (value_type (arg1));
 239
 240       if (m2_is_unbounded_array (type))
 241         {
 242           struct value *temp = arg1;
 243           type = TYPE_FIELD_TYPE (type, 0);
 244           if (type == NULL || (TYPE_CODE (type) != TYPE_CODE_PTR))
 245             {
 246               warning (_("internal error: unbounded "
 247                          "array structure is unknown"));
 248               return evaluate_subexp_standard (expect_type, exp, pos, noside);
 249             }
 250           /* i18n: Do not translate the "_m2_contents" part!  */
 251           arg1 = value_struct_elt (&temp, NULL, "_m2_contents", NULL,
 252                                    _("unbounded structure "
 253                                      "missing _m2_contents field"));
 254
 255           if (value_type (arg1) != type)
 256             arg1 = value_cast (type, arg1);
 257
 258           check_typedef (value_type (arg1));
 259           return value_ind (value_ptradd (arg1, value_as_long (arg2)));
 260         }
 261       else
 262         if (TYPE_CODE (type) != TYPE_CODE_ARRAY)
 263           {
 264             if (TYPE_NAME (type))
 265               error (_("cannot subscript something of type `%s'"),
 266                      TYPE_NAME (type));
 267             else
 268               error (_("cannot subscript requested type"));
 269           }
 270
 271       if (noside == EVAL_AVOID_SIDE_EFFECTS)
 272         return value_zero (TYPE_TARGET_TYPE (type), VALUE_LVAL (arg1));
 273       else
 274         return value_subscript (arg1, value_as_long (arg2));
 275
 276     default:
 277       return evaluate_subexp_standard (expect_type, exp, pos, noside);
 278     }
 279
 280  nosideret:
 281   return value_from_longest (builtin_type (exp->gdbarch)->builtin_int, 1);
 282 }
 283 \f
 284
 285 /* Table of operators and their precedences for printing expressions.  */
 286
 287 static const struct op_print m2_op_print_tab[] =
 288 {
 289   {"+", BINOP_ADD, PREC_ADD, 0},
 290   {"+", UNOP_PLUS, PREC_PREFIX, 0},
 291   {"-", BINOP_SUB, PREC_ADD, 0},
 292   {"-", UNOP_NEG, PREC_PREFIX, 0},
 293   {"*", BINOP_MUL, PREC_MUL, 0},
 294   {"/", BINOP_DIV, PREC_MUL, 0},
 295   {"DIV", BINOP_INTDIV, PREC_MUL, 0},
 296   {"MOD", BINOP_REM, PREC_MUL, 0},
 297   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 298   {"OR", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
 299   {"AND", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
 300   {"NOT", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 301   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 302   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 303   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 304   {">=", BINOP_GEQ, PREC_ORDER, 0},
 305   {">", BINOP_GTR, PREC_ORDER, 0},
 306   {"<", BINOP_LESS, PREC_ORDER, 0},
 307   {"^", UNOP_IND, PREC_PREFIX, 0},
 308   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 309   {"CAP", UNOP_CAP, PREC_BUILTIN_FUNCTION, 0},
 310   {"CHR", UNOP_CHR, PREC_BUILTIN_FUNCTION, 0},
 311   {"ORD", UNOP_ORD, PREC_BUILTIN_FUNCTION, 0},
 312   {"FLOAT", UNOP_FLOAT, PREC_BUILTIN_FUNCTION, 0},
 313   {"HIGH", UNOP_HIGH, PREC_BUILTIN_FUNCTION, 0},
 314   {"MAX", UNOP_MAX, PREC_BUILTIN_FUNCTION, 0},
 315   {"MIN", UNOP_MIN, PREC_BUILTIN_FUNCTION, 0},
 316   {"ODD", UNOP_ODD, PREC_BUILTIN_FUNCTION, 0},
 317   {"TRUNC", UNOP_TRUNC, PREC_BUILTIN_FUNCTION, 0},
 318   {NULL, 0, 0, 0}
 319 };
 320 \f
 321 /* The built-in types of Modula-2.  */
 322
 323 enum m2_primitive_types {
 324   m2_primitive_type_char,
 325   m2_primitive_type_int,
 326   m2_primitive_type_card,
 327   m2_primitive_type_real,
 328   m2_primitive_type_bool,
 329   nr_m2_primitive_types
 330 };
 331
 332 static void
 333 m2_language_arch_info (struct gdbarch *gdbarch,
 334                        struct language_arch_info *lai)
 335 {
 336   const struct builtin_m2_type *builtin = builtin_m2_type (gdbarch);
 337
 338   lai->string_char_type = builtin->builtin_char;
 339   lai->primitive_type_vector
 340     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_m2_primitive_types + 1,
 341                               struct type *);
 342
 343   lai->primitive_type_vector [m2_primitive_type_char]
 344     = builtin->builtin_char;
 345   lai->primitive_type_vector [m2_primitive_type_int]
 346     = builtin->builtin_int;
 347   lai->primitive_type_vector [m2_primitive_type_card]
 348     = builtin->builtin_card;
 349   lai->primitive_type_vector [m2_primitive_type_real]
 350     = builtin->builtin_real;
 351   lai->primitive_type_vector [m2_primitive_type_bool]
 352     = builtin->builtin_bool;
 353
 354   lai->bool_type_symbol = "BOOLEAN";
 355   lai->bool_type_default = builtin->builtin_bool;
 356 }
 357
 358 const struct exp_descriptor exp_descriptor_modula2 =
 359 {
 360   print_subexp_standard,
 361   operator_length_standard,
 362   operator_check_standard,
 363   op_name_standard,
 364   dump_subexp_body_standard,
 365   evaluate_subexp_modula2
 366 };
 367
 368 const struct language_defn m2_language_defn =
 369 {
 370   "modula-2",
 371   language_m2,
 372   range_check_on,
 373   type_check_on,
 374   case_sensitive_on,
 375   array_row_major,
 376   macro_expansion_no,
 377   &exp_descriptor_modula2,
 378   m2_parse,                     /* parser */
 379   m2_error,                     /* parser error function */
 380   null_post_parser,
 381   m2_printchar,                 /* Print character constant */
 382   m2_printstr,                  /* function to print string constant */
 383   m2_emit_char,                 /* Function to print a single character */
 384   m2_print_type,                /* Print a type using appropriate syntax */
 385   m2_print_typedef,             /* Print a typedef using appropriate syntax */
 386   m2_val_print,                 /* Print a value using appropriate syntax */
 387   c_value_print,                /* Print a top-level value */
 388   default_read_var_value,       /* la_read_var_value */
 389   NULL,                         /* Language specific skip_trampoline */
 390   NULL,                         /* name_of_this */
 391   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 392   basic_lookup_transparent_type,/* lookup_transparent_type */
 393   NULL,                         /* Language specific symbol demangler */
 394   NULL,                         /* Language specific
 395                                    class_name_from_physname */
 396   m2_op_print_tab,              /* expression operators for printing */
 397   0,                            /* arrays are first-class (not c-style) */
 398   0,                            /* String lower bound */
 399   default_word_break_characters,
 400   default_make_symbol_completion_list,
 401   m2_language_arch_info,
 402   default_print_array_index,
 403   default_pass_by_reference,
 404   default_get_string,
 405   NULL,                         /* la_get_symbol_name_cmp */
 406   iterate_over_symbols,
 407   LANG_MAGIC
 408 };
 409
 410 static void *
 411 build_m2_types (struct gdbarch *gdbarch)
 412 {
 413   struct builtin_m2_type *builtin_m2_type
 414     = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct builtin_m2_type);
 415
 416   /* Modula-2 "pervasive" types.  NOTE:  these can be redefined!!! */
 417   builtin_m2_type->builtin_int
 418     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 0, "INTEGER");
 419   builtin_m2_type->builtin_card
 420     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "CARDINAL");
 421   builtin_m2_type->builtin_real
 422     = arch_float_type (gdbarch, gdbarch_float_bit (gdbarch), "REAL", NULL);
 423   builtin_m2_type->builtin_char
 424     = arch_character_type (gdbarch, TARGET_CHAR_BIT, 1, "CHAR");
 425   builtin_m2_type->builtin_bool
 426     = arch_boolean_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "BOOLEAN");
 427
 428   return builtin_m2_type;
 429 }
 430
 431 static struct gdbarch_data *m2_type_data;
 432
 433 const struct builtin_m2_type *
 434 builtin_m2_type (struct gdbarch *gdbarch)
 435 {
 436   return gdbarch_data (gdbarch, m2_type_data);
 437 }
 438
 439
 440 /* Initialization for Modula-2 */
 441
 442 void
 443 _initialize_m2_language (void)
 444 {
 445   m2_type_data = gdbarch_data_register_post_init (build_m2_types);
 446
 447   add_language (&m2_language_defn);
 448 }