gdb/p-lang.c

   1 /* Pascal language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2014 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 /* This file is derived from c-lang.c */
  21
  22 #include "defs.h"
  23 #include "symtab.h"
  24 #include "gdbtypes.h"
  25 #include "expression.h"
  26 #include "parser-defs.h"
  27 #include "language.h"
  28 #include "varobj.h"
  29 #include "p-lang.h"
  30 #include "valprint.h"
  31 #include "value.h"
  32 #include <ctype.h>
  33
  34 extern void _initialize_pascal_language (void);
  35
  36
  37 /* All GPC versions until now (2007-09-27) also define a symbol called
  38    '_p_initialize'.  Check for the presence of this symbol first.  */
  39 static const char GPC_P_INITIALIZE[] = "_p_initialize";
  40
  41 /* The name of the symbol that GPC uses as the name of the main
  42    procedure (since version 20050212).  */
  43 static const char GPC_MAIN_PROGRAM_NAME_1[] = "_p__M0_main_program";
  44
  45 /* Older versions of GPC (versions older than 20050212) were using
  46    a different name for the main procedure.  */
  47 static const char GPC_MAIN_PROGRAM_NAME_2[] = "pascal_main_program";
  48
  49 /* Function returning the special symbol name used
  50    by GPC for the main procedure in the main program
  51    if it is found in minimal symbol list.
  52    This function tries to find minimal symbols generated by GPC
  53    so that it finds the even if the program was compiled
  54    without debugging information.
  55    According to information supplied by Waldeck Hebisch,
  56    this should work for all versions posterior to June 2000.  */
  57
  58 const char *
  59 pascal_main_name (void)
  60 {
  61   struct bound_minimal_symbol msym;
  62
  63   msym = lookup_minimal_symbol (GPC_P_INITIALIZE, NULL, NULL);
  64
  65   /*  If '_p_initialize' was not found, the main program is likely not
  66      written in Pascal.  */
  67   if (msym.minsym == NULL)
  68     return NULL;
  69
  70   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_1, NULL, NULL);
  71   if (msym.minsym != NULL)
  72     {
  73       return GPC_MAIN_PROGRAM_NAME_1;
  74     }
  75
  76   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_2, NULL, NULL);
  77   if (msym.minsym != NULL)
  78     {
  79       return GPC_MAIN_PROGRAM_NAME_2;
  80     }
  81
  82   /*  No known entry procedure found, the main program is probably
  83       not compiled with GPC.  */
  84   return NULL;
  85 }
  86
  87 /* Determines if type TYPE is a pascal string type.
  88    Returns a positive value if the type is a known pascal string type.
  89    This function is used by p-valprint.c code to allow better string display.
  90    If it is a pascal string type, then it also sets info needed
  91    to get the length and the data of the string
  92    length_pos, length_size and string_pos are given in bytes.
  93    char_size gives the element size in bytes.
  94    FIXME: if the position or the size of these fields
  95    are not multiple of TARGET_CHAR_BIT then the results are wrong
  96    but this does not happen for Free Pascal nor for GPC.  */
  97 int
  98 is_pascal_string_type (struct type *type,int *length_pos,
  99                        int *length_size, int *string_pos,
 100                        struct type **char_type,
 101                        const char **arrayname)
 102 {
 103   if (type != NULL && TYPE_CODE (type) == TYPE_CODE_STRUCT)
 104     {
 105       /* Old Borland type pascal strings from Free Pascal Compiler.  */
 106       /* Two fields: length and st.  */
 107       if (TYPE_NFIELDS (type) == 2
 108           && TYPE_FIELD_NAME (type, 0)
 109           && strcmp (TYPE_FIELD_NAME (type, 0), "length") == 0
 110           && TYPE_FIELD_NAME (type, 1)
 111           && strcmp (TYPE_FIELD_NAME (type, 1), "st") == 0)
 112         {
 113           if (length_pos)
 114             *length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
 115           if (length_size)
 116             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0));
 117           if (string_pos)
 118             *string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 119           if (char_type)
 120             *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 1));
 121           if (arrayname)
 122             *arrayname = TYPE_FIELD_NAME (type, 1);
 123          return 2;
 124         };
 125       /* GNU pascal strings.  */
 126       /* Three fields: Capacity, length and schema$ or _p_schema.  */
 127       if (TYPE_NFIELDS (type) == 3
 128           && TYPE_FIELD_NAME (type, 0)
 129           && strcmp (TYPE_FIELD_NAME (type, 0), "Capacity") == 0
 130           && TYPE_FIELD_NAME (type, 1)
 131           && strcmp (TYPE_FIELD_NAME (type, 1), "length") == 0)
 132         {
 133           if (length_pos)
 134             *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 135           if (length_size)
 136             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 1));
 137           if (string_pos)
 138             *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
 139           /* FIXME: how can I detect wide chars in GPC ??  */
 140           if (char_type)
 141             {
 142               *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 2));
 143
 144               if (TYPE_CODE (*char_type) == TYPE_CODE_ARRAY)
 145                 *char_type = TYPE_TARGET_TYPE (*char_type);
 146             }
 147           if (arrayname)
 148             *arrayname = TYPE_FIELD_NAME (type, 2);
 149          return 3;
 150         };
 151     }
 152   return 0;
 153 }
 154
 155 static void pascal_one_char (int, struct ui_file *, int *);
 156
 157 /* Print the character C on STREAM as part of the contents of a literal
 158    string.
 159    In_quotes is reset to 0 if a char is written with #4 notation.  */
 160
 161 static void
 162 pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
 163 {
 164   if (c == '\'' || ((unsigned int) c <= 0xff && (PRINT_LITERAL_FORM (c))))
 165     {
 166       if (!(*in_quotes))
 167         fputs_filtered ("'", stream);
 168       *in_quotes = 1;
 169       if (c == '\'')
 170         {
 171           fputs_filtered ("''", stream);
 172         }
 173       else
 174         fprintf_filtered (stream, "%c", c);
 175     }
 176   else
 177     {
 178       if (*in_quotes)
 179         fputs_filtered ("'", stream);
 180       *in_quotes = 0;
 181       fprintf_filtered (stream, "#%d", (unsigned int) c);
 182     }
 183 }
 184
 185 static void pascal_emit_char (int c, struct type *type,
 186                               struct ui_file *stream, int quoter);
 187
 188 /* Print the character C on STREAM as part of the contents of a literal
 189    string whose delimiter is QUOTER.  Note that that format for printing
 190    characters and strings is language specific.  */
 191
 192 static void
 193 pascal_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
 194 {
 195   int in_quotes = 0;
 196
 197   pascal_one_char (c, stream, &in_quotes);
 198   if (in_quotes)
 199     fputs_filtered ("'", stream);
 200 }
 201
 202 void
 203 pascal_printchar (int c, struct type *type, struct ui_file *stream)
 204 {
 205   int in_quotes = 0;
 206
 207   pascal_one_char (c, stream, &in_quotes);
 208   if (in_quotes)
 209     fputs_filtered ("'", stream);
 210 }
 211
 212 /* Print the character string STRING, printing at most LENGTH characters.
 213    Printing stops early if the number hits print_max; repeat counts
 214    are printed as appropriate.  Print ellipses at the end if we
 215    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.  */
 216
 217 void
 218 pascal_printstr (struct ui_file *stream, struct type *type,
 219                  const gdb_byte *string, unsigned int length,
 220                  const char *encoding, int force_ellipses,
 221                  const struct value_print_options *options)
 222 {
 223   enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
 224   unsigned int i;
 225   unsigned int things_printed = 0;
 226   int in_quotes = 0;
 227   int need_comma = 0;
 228   int width;
 229
 230   /* Preserve TYPE's original type, just set its LENGTH.  */
 231   check_typedef (type);
 232   width = TYPE_LENGTH (type);
 233
 234   /* If the string was not truncated due to `set print elements', and
 235      the last byte of it is a null, we don't print that, in traditional C
 236      style.  */
 237   if ((!force_ellipses) && length > 0
 238         && extract_unsigned_integer (string + (length - 1) * width, width,
 239                                      byte_order) == 0)
 240     length--;
 241
 242   if (length == 0)
 243     {
 244       fputs_filtered ("''", stream);
 245       return;
 246     }
 247
 248   for (i = 0; i < length && things_printed < options->print_max; ++i)
 249     {
 250       /* Position of the character we are examining
 251          to see whether it is repeated.  */
 252       unsigned int rep1;
 253       /* Number of repetitions we have detected so far.  */
 254       unsigned int reps;
 255       unsigned long int current_char;
 256
 257       QUIT;
 258
 259       if (need_comma)
 260         {
 261           fputs_filtered (", ", stream);
 262           need_comma = 0;
 263         }
 264
 265       current_char = extract_unsigned_integer (string + i * width, width,
 266                                                byte_order);
 267
 268       rep1 = i + 1;
 269       reps = 1;
 270       while (rep1 < length
 271              && extract_unsigned_integer (string + rep1 * width, width,
 272                                           byte_order) == current_char)
 273         {
 274           ++rep1;
 275           ++reps;
 276         }
 277
 278       if (reps > options->repeat_count_threshold)
 279         {
 280           if (in_quotes)
 281             {
 282               fputs_filtered ("', ", stream);
 283               in_quotes = 0;
 284             }
 285           pascal_printchar (current_char, type, stream);
 286           fprintf_filtered (stream, " <repeats %u times>", reps);
 287           i = rep1 - 1;
 288           things_printed += options->repeat_count_threshold;
 289           need_comma = 1;
 290         }
 291       else
 292         {
 293           if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 294             {
 295               fputs_filtered ("'", stream);
 296               in_quotes = 1;
 297             }
 298           pascal_one_char (current_char, stream, &in_quotes);
 299           ++things_printed;
 300         }
 301     }
 302
 303   /* Terminate the quotes if necessary.  */
 304   if (in_quotes)
 305     fputs_filtered ("'", stream);
 306
 307   if (force_ellipses || i < length)
 308     fputs_filtered ("...", stream);
 309 }
 310 \f
 311
 312 /* Table mapping opcodes into strings for printing operators
 313    and precedences of the operators.  */
 314
 315 const struct op_print pascal_op_print_tab[] =
 316 {
 317   {",", BINOP_COMMA, PREC_COMMA, 0},
 318   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 319   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 320   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 321   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 322   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 323   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 324   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 325   {">=", BINOP_GEQ, PREC_ORDER, 0},
 326   {">", BINOP_GTR, PREC_ORDER, 0},
 327   {"<", BINOP_LESS, PREC_ORDER, 0},
 328   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 329   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 330   {"+", BINOP_ADD, PREC_ADD, 0},
 331   {"-", BINOP_SUB, PREC_ADD, 0},
 332   {"*", BINOP_MUL, PREC_MUL, 0},
 333   {"/", BINOP_DIV, PREC_MUL, 0},
 334   {"div", BINOP_INTDIV, PREC_MUL, 0},
 335   {"mod", BINOP_REM, PREC_MUL, 0},
 336   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 337   {"-", UNOP_NEG, PREC_PREFIX, 0},
 338   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 339   {"^", UNOP_IND, PREC_SUFFIX, 1},
 340   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 341   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 342   {NULL, 0, 0, 0}
 343 };
 344 \f
 345 enum pascal_primitive_types {
 346   pascal_primitive_type_int,
 347   pascal_primitive_type_long,
 348   pascal_primitive_type_short,
 349   pascal_primitive_type_char,
 350   pascal_primitive_type_float,
 351   pascal_primitive_type_double,
 352   pascal_primitive_type_void,
 353   pascal_primitive_type_long_long,
 354   pascal_primitive_type_signed_char,
 355   pascal_primitive_type_unsigned_char,
 356   pascal_primitive_type_unsigned_short,
 357   pascal_primitive_type_unsigned_int,
 358   pascal_primitive_type_unsigned_long,
 359   pascal_primitive_type_unsigned_long_long,
 360   pascal_primitive_type_long_double,
 361   pascal_primitive_type_complex,
 362   pascal_primitive_type_double_complex,
 363   nr_pascal_primitive_types
 364 };
 365
 366 static void
 367 pascal_language_arch_info (struct gdbarch *gdbarch,
 368                            struct language_arch_info *lai)
 369 {
 370   const struct builtin_type *builtin = builtin_type (gdbarch);
 371
 372   lai->string_char_type = builtin->builtin_char;
 373   lai->primitive_type_vector
 374     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 375                               struct type *);
 376   lai->primitive_type_vector [pascal_primitive_type_int]
 377     = builtin->builtin_int;
 378   lai->primitive_type_vector [pascal_primitive_type_long]
 379     = builtin->builtin_long;
 380   lai->primitive_type_vector [pascal_primitive_type_short]
 381     = builtin->builtin_short;
 382   lai->primitive_type_vector [pascal_primitive_type_char]
 383     = builtin->builtin_char;
 384   lai->primitive_type_vector [pascal_primitive_type_float]
 385     = builtin->builtin_float;
 386   lai->primitive_type_vector [pascal_primitive_type_double]
 387     = builtin->builtin_double;
 388   lai->primitive_type_vector [pascal_primitive_type_void]
 389     = builtin->builtin_void;
 390   lai->primitive_type_vector [pascal_primitive_type_long_long]
 391     = builtin->builtin_long_long;
 392   lai->primitive_type_vector [pascal_primitive_type_signed_char]
 393     = builtin->builtin_signed_char;
 394   lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 395     = builtin->builtin_unsigned_char;
 396   lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 397     = builtin->builtin_unsigned_short;
 398   lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 399     = builtin->builtin_unsigned_int;
 400   lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 401     = builtin->builtin_unsigned_long;
 402   lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 403     = builtin->builtin_unsigned_long_long;
 404   lai->primitive_type_vector [pascal_primitive_type_long_double]
 405     = builtin->builtin_long_double;
 406   lai->primitive_type_vector [pascal_primitive_type_complex]
 407     = builtin->builtin_complex;
 408   lai->primitive_type_vector [pascal_primitive_type_double_complex]
 409     = builtin->builtin_double_complex;
 410
 411   lai->bool_type_symbol = "boolean";
 412   lai->bool_type_default = builtin->builtin_bool;
 413 }
 414
 415 const struct language_defn pascal_language_defn =
 416 {
 417   "pascal",                     /* Language name */
 418   "Pascal",
 419   language_pascal,
 420   range_check_on,
 421   case_sensitive_on,
 422   array_row_major,
 423   macro_expansion_no,
 424   &exp_descriptor_standard,
 425   pascal_parse,
 426   pascal_error,
 427   null_post_parser,
 428   pascal_printchar,             /* Print a character constant */
 429   pascal_printstr,              /* Function to print string constant */
 430   pascal_emit_char,             /* Print a single char */
 431   pascal_print_type,            /* Print a type using appropriate syntax */
 432   pascal_print_typedef,         /* Print a typedef using appropriate syntax */
 433   pascal_val_print,             /* Print a value using appropriate syntax */
 434   pascal_value_print,           /* Print a top-level value */
 435   default_read_var_value,       /* la_read_var_value */
 436   NULL,                         /* Language specific skip_trampoline */
 437   "this",                       /* name_of_this */
 438   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 439   basic_lookup_transparent_type,/* lookup_transparent_type */
 440   NULL,                         /* Language specific symbol demangler */
 441   NULL,                         /* Language specific class_name_from_physname */
 442   pascal_op_print_tab,          /* expression operators for printing */
 443   1,                            /* c-style arrays */
 444   0,                            /* String lower bound */
 445   default_word_break_characters,
 446   default_make_symbol_completion_list,
 447   pascal_language_arch_info,
 448   default_print_array_index,
 449   default_pass_by_reference,
 450   default_get_string,
 451   NULL,                         /* la_get_symbol_name_cmp */
 452   iterate_over_symbols,
 453   &default_varobj_ops,
 454   NULL,
 455   NULL,
 456   LANG_MAGIC
 457 };
 458
 459 void
 460 _initialize_pascal_language (void)
 461 {
 462   add_language (&pascal_language_defn);
 463 }