gdb/m2-lang.c

   1 /* Modula 2 language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 2000, 2002, 2003, 2004,
   4    2005, 2007, 2008, 2009, 2010 Free 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   int width = TYPE_LENGTH (type);
 115
 116   if (length == 0)
 117     {
 118       fputs_filtered ("\"\"", gdb_stdout);
 119       return;
 120     }
 121
 122   for (i = 0; i < length && things_printed < options->print_max; ++i)
 123     {
 124       /* Position of the character we are examining
 125          to see whether it is repeated.  */
 126       unsigned int rep1;
 127       /* Number of repetitions we have detected so far.  */
 128       unsigned int reps;
 129
 130       QUIT;
 131
 132       if (need_comma)
 133         {
 134           fputs_filtered (", ", stream);
 135           need_comma = 0;
 136         }
 137
 138       rep1 = i + 1;
 139       reps = 1;
 140       while (rep1 < length && string[rep1] == string[i])
 141         {
 142           ++rep1;
 143           ++reps;
 144         }
 145
 146       if (reps > options->repeat_count_threshold)
 147         {
 148           if (in_quotes)
 149             {
 150               if (options->inspect_it)
 151                 fputs_filtered ("\\\", ", stream);
 152               else
 153                 fputs_filtered ("\", ", stream);
 154               in_quotes = 0;
 155             }
 156           m2_printchar (string[i], type, stream);
 157           fprintf_filtered (stream, " <repeats %u times>", reps);
 158           i = rep1 - 1;
 159           things_printed += options->repeat_count_threshold;
 160           need_comma = 1;
 161         }
 162       else
 163         {
 164           if (!in_quotes)
 165             {
 166               if (options->inspect_it)
 167                 fputs_filtered ("\\\"", stream);
 168               else
 169                 fputs_filtered ("\"", stream);
 170               in_quotes = 1;
 171             }
 172           LA_EMIT_CHAR (string[i], type, stream, '"');
 173           ++things_printed;
 174         }
 175     }
 176
 177   /* Terminate the quotes if necessary.  */
 178   if (in_quotes)
 179     {
 180       if (options->inspect_it)
 181         fputs_filtered ("\\\"", stream);
 182       else
 183         fputs_filtered ("\"", stream);
 184     }
 185
 186   if (force_ellipses || i < length)
 187     fputs_filtered ("...", stream);
 188 }
 189
 190 static struct value *
 191 evaluate_subexp_modula2 (struct type *expect_type, struct expression *exp,
 192                          int *pos, enum noside noside)
 193 {
 194   enum exp_opcode op = exp->elts[*pos].opcode;
 195   struct value *arg1;
 196   struct value *arg2;
 197   struct type *type;
 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               type = TYPE_FIELD_TYPE (type, 1);
 215               /* i18n: Do not translate the "_m2_high" part!  */
 216               arg1 = value_struct_elt (&temp, NULL, "_m2_high", NULL,
 217                                        _("unbounded structure "
 218                                          "missing _m2_high field"));
 219
 220               if (value_type (arg1) != type)
 221                 arg1 = value_cast (type, arg1);
 222             }
 223         }
 224       return arg1;
 225
 226     case BINOP_SUBSCRIPT:
 227       (*pos)++;
 228       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
 229       arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
 230       if (noside == EVAL_SKIP)
 231         goto nosideret;
 232       /* If the user attempts to subscript something that is not an
 233          array or pointer type (like a plain int variable for example),
 234          then report this as an error.  */
 235
 236       arg1 = coerce_ref (arg1);
 237       type = check_typedef (value_type (arg1));
 238
 239       if (m2_is_unbounded_array (type))
 240         {
 241           struct value *temp = arg1;
 242           type = TYPE_FIELD_TYPE (type, 0);
 243           if (type == NULL || (TYPE_CODE (type) != TYPE_CODE_PTR)) {
 244             warning (_("internal error: unbounded array structure is unknown"));
 245             return evaluate_subexp_standard (expect_type, exp, pos, noside);
 246           }
 247           /* i18n: Do not translate the "_m2_contents" part!  */
 248           arg1 = value_struct_elt (&temp, NULL, "_m2_contents", NULL,
 249                                    _("unbounded structure "
 250                                      "missing _m2_contents field"));
 251
 252           if (value_type (arg1) != type)
 253             arg1 = value_cast (type, arg1);
 254
 255           type = check_typedef (value_type (arg1));
 256           return value_ind (value_ptradd (arg1, value_as_long (arg2)));
 257         }
 258       else
 259         if (TYPE_CODE (type) != TYPE_CODE_ARRAY)
 260           {
 261             if (TYPE_NAME (type))
 262               error (_("cannot subscript something of type `%s'"),
 263                      TYPE_NAME (type));
 264             else
 265               error (_("cannot subscript requested type"));
 266           }
 267
 268       if (noside == EVAL_AVOID_SIDE_EFFECTS)
 269         return value_zero (TYPE_TARGET_TYPE (type), VALUE_LVAL (arg1));
 270       else
 271         return value_subscript (arg1, value_as_long (arg2));
 272
 273     default:
 274       return evaluate_subexp_standard (expect_type, exp, pos, noside);
 275     }
 276
 277  nosideret:
 278   return value_from_longest (builtin_type (exp->gdbarch)->builtin_int, 1);
 279 }
 280 \f
 281
 282 /* Table of operators and their precedences for printing expressions.  */
 283
 284 static const struct op_print m2_op_print_tab[] =
 285 {
 286   {"+", BINOP_ADD, PREC_ADD, 0},
 287   {"+", UNOP_PLUS, PREC_PREFIX, 0},
 288   {"-", BINOP_SUB, PREC_ADD, 0},
 289   {"-", UNOP_NEG, PREC_PREFIX, 0},
 290   {"*", BINOP_MUL, PREC_MUL, 0},
 291   {"/", BINOP_DIV, PREC_MUL, 0},
 292   {"DIV", BINOP_INTDIV, PREC_MUL, 0},
 293   {"MOD", BINOP_REM, PREC_MUL, 0},
 294   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 295   {"OR", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
 296   {"AND", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
 297   {"NOT", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 298   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 299   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 300   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 301   {">=", BINOP_GEQ, PREC_ORDER, 0},
 302   {">", BINOP_GTR, PREC_ORDER, 0},
 303   {"<", BINOP_LESS, PREC_ORDER, 0},
 304   {"^", UNOP_IND, PREC_PREFIX, 0},
 305   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 306   {"CAP", UNOP_CAP, PREC_BUILTIN_FUNCTION, 0},
 307   {"CHR", UNOP_CHR, PREC_BUILTIN_FUNCTION, 0},
 308   {"ORD", UNOP_ORD, PREC_BUILTIN_FUNCTION, 0},
 309   {"FLOAT", UNOP_FLOAT, PREC_BUILTIN_FUNCTION, 0},
 310   {"HIGH", UNOP_HIGH, PREC_BUILTIN_FUNCTION, 0},
 311   {"MAX", UNOP_MAX, PREC_BUILTIN_FUNCTION, 0},
 312   {"MIN", UNOP_MIN, PREC_BUILTIN_FUNCTION, 0},
 313   {"ODD", UNOP_ODD, PREC_BUILTIN_FUNCTION, 0},
 314   {"TRUNC", UNOP_TRUNC, PREC_BUILTIN_FUNCTION, 0},
 315   {NULL, 0, 0, 0}
 316 };
 317 \f
 318 /* The built-in types of Modula-2.  */
 319
 320 enum m2_primitive_types {
 321   m2_primitive_type_char,
 322   m2_primitive_type_int,
 323   m2_primitive_type_card,
 324   m2_primitive_type_real,
 325   m2_primitive_type_bool,
 326   nr_m2_primitive_types
 327 };
 328
 329 static void
 330 m2_language_arch_info (struct gdbarch *gdbarch,
 331                        struct language_arch_info *lai)
 332 {
 333   const struct builtin_m2_type *builtin = builtin_m2_type (gdbarch);
 334
 335   lai->string_char_type = builtin->builtin_char;
 336   lai->primitive_type_vector
 337     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_m2_primitive_types + 1,
 338                               struct type *);
 339
 340   lai->primitive_type_vector [m2_primitive_type_char]
 341     = builtin->builtin_char;
 342   lai->primitive_type_vector [m2_primitive_type_int]
 343     = builtin->builtin_int;
 344   lai->primitive_type_vector [m2_primitive_type_card]
 345     = builtin->builtin_card;
 346   lai->primitive_type_vector [m2_primitive_type_real]
 347     = builtin->builtin_real;
 348   lai->primitive_type_vector [m2_primitive_type_bool]
 349     = builtin->builtin_bool;
 350
 351   lai->bool_type_symbol = "BOOLEAN";
 352   lai->bool_type_default = builtin->builtin_bool;
 353 }
 354
 355 const struct exp_descriptor exp_descriptor_modula2 =
 356 {
 357   print_subexp_standard,
 358   operator_length_standard,
 359   op_name_standard,
 360   dump_subexp_body_standard,
 361   evaluate_subexp_modula2
 362 };
 363
 364 const struct language_defn m2_language_defn =
 365 {
 366   "modula-2",
 367   language_m2,
 368   range_check_on,
 369   type_check_on,
 370   case_sensitive_on,
 371   array_row_major,
 372   macro_expansion_no,
 373   &exp_descriptor_modula2,
 374   m2_parse,                     /* parser */
 375   m2_error,                     /* parser error function */
 376   null_post_parser,
 377   m2_printchar,                 /* Print character constant */
 378   m2_printstr,                  /* function to print string constant */
 379   m2_emit_char,                 /* Function to print a single character */
 380   m2_print_type,                /* Print a type using appropriate syntax */
 381   m2_print_typedef,             /* Print a typedef using appropriate syntax */
 382   m2_val_print,                 /* Print a value using appropriate syntax */
 383   c_value_print,                /* Print a top-level value */
 384   NULL,                         /* Language specific skip_trampoline */
 385   NULL,                         /* name_of_this */
 386   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 387   basic_lookup_transparent_type,/* lookup_transparent_type */
 388   NULL,                         /* Language specific symbol demangler */
 389   NULL,                         /* Language specific class_name_from_physname */
 390   m2_op_print_tab,              /* expression operators for printing */
 391   0,                            /* arrays are first-class (not c-style) */
 392   0,                            /* String lower bound */
 393   default_word_break_characters,
 394   default_make_symbol_completion_list,
 395   m2_language_arch_info,
 396   default_print_array_index,
 397   default_pass_by_reference,
 398   default_get_string,
 399   LANG_MAGIC
 400 };
 401
 402 static void *
 403 build_m2_types (struct gdbarch *gdbarch)
 404 {
 405   struct builtin_m2_type *builtin_m2_type
 406     = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct builtin_m2_type);
 407
 408   /* Modula-2 "pervasive" types.  NOTE:  these can be redefined!!! */
 409   builtin_m2_type->builtin_int
 410     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 0, "INTEGER");
 411   builtin_m2_type->builtin_card
 412     = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "CARDINAL");
 413   builtin_m2_type->builtin_real
 414     = arch_float_type (gdbarch, gdbarch_float_bit (gdbarch), "REAL", NULL);
 415   builtin_m2_type->builtin_char
 416     = arch_character_type (gdbarch, TARGET_CHAR_BIT, 1, "CHAR");
 417   builtin_m2_type->builtin_bool
 418     = arch_boolean_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "BOOLEAN");
 419
 420   return builtin_m2_type;
 421 }
 422
 423 static struct gdbarch_data *m2_type_data;
 424
 425 const struct builtin_m2_type *
 426 builtin_m2_type (struct gdbarch *gdbarch)
 427 {
 428   return gdbarch_data (gdbarch, m2_type_data);
 429 }
 430
 431
 432 /* Initialization for Modula-2 */
 433
 434 void
 435 _initialize_m2_language (void)
 436 {
 437   m2_type_data = gdbarch_data_register_post_init (build_m2_types);
 438
 439   add_language (&m2_language_defn);
 440 }