gdb/p-lang.c

   1 /* Pascal language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2013 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 <string.h>
  24 #include "symtab.h"
  25 #include "gdbtypes.h"
  26 #include "expression.h"
  27 #include "parser-defs.h"
  28 #include "language.h"
  29 #include "varobj.h"
  30 #include "p-lang.h"
  31 #include "valprint.h"
  32 #include "value.h"
  33 #include <ctype.h>
  34
  35 extern void _initialize_pascal_language (void);
  36
  37
  38 /* All GPC versions until now (2007-09-27) also define a symbol called
  39    '_p_initialize'.  Check for the presence of this symbol first.  */
  40 static const char GPC_P_INITIALIZE[] = "_p_initialize";
  41
  42 /* The name of the symbol that GPC uses as the name of the main
  43    procedure (since version 20050212).  */
  44 static const char GPC_MAIN_PROGRAM_NAME_1[] = "_p__M0_main_program";
  45
  46 /* Older versions of GPC (versions older than 20050212) were using
  47    a different name for the main procedure.  */
  48 static const char GPC_MAIN_PROGRAM_NAME_2[] = "pascal_main_program";
  49
  50 /* Function returning the special symbol name used
  51    by GPC for the main procedure in the main program
  52    if it is found in minimal symbol list.
  53    This function tries to find minimal symbols generated by GPC
  54    so that it finds the even if the program was compiled
  55    without debugging information.
  56    According to information supplied by Waldeck Hebisch,
  57    this should work for all versions posterior to June 2000.  */
  58
  59 const char *
  60 pascal_main_name (void)
  61 {
  62   struct minimal_symbol *msym;
  63
  64   msym = lookup_minimal_symbol (GPC_P_INITIALIZE, NULL, NULL);
  65
  66   /*  If '_p_initialize' was not found, the main program is likely not
  67      written in Pascal.  */
  68   if (msym == NULL)
  69     return NULL;
  70
  71   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_1, NULL, NULL);
  72   if (msym != NULL)
  73     {
  74       return GPC_MAIN_PROGRAM_NAME_1;
  75     }
  76
  77   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_2, NULL, NULL);
  78   if (msym != NULL)
  79     {
  80       return GPC_MAIN_PROGRAM_NAME_2;
  81     }
  82
  83   /*  No known entry procedure found, the main program is probably
  84       not compiled with GPC.  */
  85   return NULL;
  86 }
  87
  88 /* Determines if type TYPE is a pascal string type.
  89    Returns a positive value if the type is a known pascal string type.
  90    This function is used by p-valprint.c code to allow better string display.
  91    If it is a pascal string type, then it also sets info needed
  92    to get the length and the data of the string
  93    length_pos, length_size and string_pos are given in bytes.
  94    char_size gives the element size in bytes.
  95    FIXME: if the position or the size of these fields
  96    are not multiple of TARGET_CHAR_BIT then the results are wrong
  97    but this does not happen for Free Pascal nor for GPC.  */
  98 int
  99 is_pascal_string_type (struct type *type,int *length_pos,
 100                        int *length_size, int *string_pos,
 101                        struct type **char_type,
 102                        const char **arrayname)
 103 {
 104   if (type != NULL && TYPE_CODE (type) == TYPE_CODE_STRUCT)
 105     {
 106       /* Old Borland type pascal strings from Free Pascal Compiler.  */
 107       /* Two fields: length and st.  */
 108       if (TYPE_NFIELDS (type) == 2
 109           && TYPE_FIELD_NAME (type, 0)
 110           && strcmp (TYPE_FIELD_NAME (type, 0), "length") == 0
 111           && TYPE_FIELD_NAME (type, 1)
 112           && strcmp (TYPE_FIELD_NAME (type, 1), "st") == 0)
 113         {
 114           if (length_pos)
 115             *length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
 116           if (length_size)
 117             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0));
 118           if (string_pos)
 119             *string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 120           if (char_type)
 121             *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 1));
 122           if (arrayname)
 123             *arrayname = TYPE_FIELD_NAME (type, 1);
 124          return 2;
 125         };
 126       /* GNU pascal strings.  */
 127       /* Three fields: Capacity, length and schema$ or _p_schema.  */
 128       if (TYPE_NFIELDS (type) == 3
 129           && TYPE_FIELD_NAME (type, 0)
 130           && strcmp (TYPE_FIELD_NAME (type, 0), "Capacity") == 0
 131           && TYPE_FIELD_NAME (type, 1)
 132           && strcmp (TYPE_FIELD_NAME (type, 1), "length") == 0)
 133         {
 134           if (length_pos)
 135             *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 136           if (length_size)
 137             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 1));
 138           if (string_pos)
 139             *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
 140           /* FIXME: how can I detect wide chars in GPC ??  */
 141           if (char_type)
 142             {
 143               *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 2));
 144
 145               if (TYPE_CODE (*char_type) == TYPE_CODE_ARRAY)
 146                 *char_type = TYPE_TARGET_TYPE (*char_type);
 147             }
 148           if (arrayname)
 149             *arrayname = TYPE_FIELD_NAME (type, 2);
 150          return 3;
 151         };
 152     }
 153   return 0;
 154 }
 155
 156 static void pascal_one_char (int, struct ui_file *, int *);
 157
 158 /* Print the character C on STREAM as part of the contents of a literal
 159    string.
 160    In_quotes is reset to 0 if a char is written with #4 notation.  */
 161
 162 static void
 163 pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
 164 {
 165   if (c == '\'' || ((unsigned int) c <= 0xff && (PRINT_LITERAL_FORM (c))))
 166     {
 167       if (!(*in_quotes))
 168         fputs_filtered ("'", stream);
 169       *in_quotes = 1;
 170       if (c == '\'')
 171         {
 172           fputs_filtered ("''", stream);
 173         }
 174       else
 175         fprintf_filtered (stream, "%c", c);
 176     }
 177   else
 178     {
 179       if (*in_quotes)
 180         fputs_filtered ("'", stream);
 181       *in_quotes = 0;
 182       fprintf_filtered (stream, "#%d", (unsigned int) c);
 183     }
 184 }
 185
 186 static void pascal_emit_char (int c, struct type *type,
 187                               struct ui_file *stream, int quoter);
 188
 189 /* Print the character C on STREAM as part of the contents of a literal
 190    string whose delimiter is QUOTER.  Note that that format for printing
 191    characters and strings is language specific.  */
 192
 193 static void
 194 pascal_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
 195 {
 196   int in_quotes = 0;
 197
 198   pascal_one_char (c, stream, &in_quotes);
 199   if (in_quotes)
 200     fputs_filtered ("'", stream);
 201 }
 202
 203 void
 204 pascal_printchar (int c, struct type *type, struct ui_file *stream)
 205 {
 206   int in_quotes = 0;
 207
 208   pascal_one_char (c, stream, &in_quotes);
 209   if (in_quotes)
 210     fputs_filtered ("'", stream);
 211 }
 212
 213 /* Print the character string STRING, printing at most LENGTH characters.
 214    Printing stops early if the number hits print_max; repeat counts
 215    are printed as appropriate.  Print ellipses at the end if we
 216    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.  */
 217
 218 void
 219 pascal_printstr (struct ui_file *stream, struct type *type,
 220                  const gdb_byte *string, unsigned int length,
 221                  const char *encoding, int force_ellipses,
 222                  const struct value_print_options *options)
 223 {
 224   enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
 225   unsigned int i;
 226   unsigned int things_printed = 0;
 227   int in_quotes = 0;
 228   int need_comma = 0;
 229   int width;
 230
 231   /* Preserve TYPE's original type, just set its LENGTH.  */
 232   check_typedef (type);
 233   width = TYPE_LENGTH (type);
 234
 235   /* If the string was not truncated due to `set print elements', and
 236      the last byte of it is a null, we don't print that, in traditional C
 237      style.  */
 238   if ((!force_ellipses) && length > 0
 239         && extract_unsigned_integer (string + (length - 1) * width, width,
 240                                      byte_order) == 0)
 241     length--;
 242
 243   if (length == 0)
 244     {
 245       fputs_filtered ("''", stream);
 246       return;
 247     }
 248
 249   for (i = 0; i < length && things_printed < options->print_max; ++i)
 250     {
 251       /* Position of the character we are examining
 252          to see whether it is repeated.  */
 253       unsigned int rep1;
 254       /* Number of repetitions we have detected so far.  */
 255       unsigned int reps;
 256       unsigned long int current_char;
 257
 258       QUIT;
 259
 260       if (need_comma)
 261         {
 262           fputs_filtered (", ", stream);
 263           need_comma = 0;
 264         }
 265
 266       current_char = extract_unsigned_integer (string + i * width, width,
 267                                                byte_order);
 268
 269       rep1 = i + 1;
 270       reps = 1;
 271       while (rep1 < length
 272              && extract_unsigned_integer (string + rep1 * width, width,
 273                                           byte_order) == current_char)
 274         {
 275           ++rep1;
 276           ++reps;
 277         }
 278
 279       if (reps > options->repeat_count_threshold)
 280         {
 281           if (in_quotes)
 282             {
 283               fputs_filtered ("', ", stream);
 284               in_quotes = 0;
 285             }
 286           pascal_printchar (current_char, type, stream);
 287           fprintf_filtered (stream, " <repeats %u times>", reps);
 288           i = rep1 - 1;
 289           things_printed += options->repeat_count_threshold;
 290           need_comma = 1;
 291         }
 292       else
 293         {
 294           if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 295             {
 296               fputs_filtered ("'", stream);
 297               in_quotes = 1;
 298             }
 299           pascal_one_char (current_char, stream, &in_quotes);
 300           ++things_printed;
 301         }
 302     }
 303
 304   /* Terminate the quotes if necessary.  */
 305   if (in_quotes)
 306     fputs_filtered ("'", stream);
 307
 308   if (force_ellipses || i < length)
 309     fputs_filtered ("...", stream);
 310 }
 311 \f
 312
 313 /* Table mapping opcodes into strings for printing operators
 314    and precedences of the operators.  */
 315
 316 const struct op_print pascal_op_print_tab[] =
 317 {
 318   {",", BINOP_COMMA, PREC_COMMA, 0},
 319   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 320   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 321   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 322   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 323   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 324   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 325   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 326   {">=", BINOP_GEQ, PREC_ORDER, 0},
 327   {">", BINOP_GTR, PREC_ORDER, 0},
 328   {"<", BINOP_LESS, PREC_ORDER, 0},
 329   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 330   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 331   {"+", BINOP_ADD, PREC_ADD, 0},
 332   {"-", BINOP_SUB, PREC_ADD, 0},
 333   {"*", BINOP_MUL, PREC_MUL, 0},
 334   {"/", BINOP_DIV, PREC_MUL, 0},
 335   {"div", BINOP_INTDIV, PREC_MUL, 0},
 336   {"mod", BINOP_REM, PREC_MUL, 0},
 337   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 338   {"-", UNOP_NEG, PREC_PREFIX, 0},
 339   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 340   {"^", UNOP_IND, PREC_SUFFIX, 1},
 341   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 342   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 343   {NULL, 0, 0, 0}
 344 };
 345 \f
 346 enum pascal_primitive_types {
 347   pascal_primitive_type_int,
 348   pascal_primitive_type_long,
 349   pascal_primitive_type_short,
 350   pascal_primitive_type_char,
 351   pascal_primitive_type_float,
 352   pascal_primitive_type_double,
 353   pascal_primitive_type_void,
 354   pascal_primitive_type_long_long,
 355   pascal_primitive_type_signed_char,
 356   pascal_primitive_type_unsigned_char,
 357   pascal_primitive_type_unsigned_short,
 358   pascal_primitive_type_unsigned_int,
 359   pascal_primitive_type_unsigned_long,
 360   pascal_primitive_type_unsigned_long_long,
 361   pascal_primitive_type_long_double,
 362   pascal_primitive_type_complex,
 363   pascal_primitive_type_double_complex,
 364   nr_pascal_primitive_types
 365 };
 366
 367 static void
 368 pascal_language_arch_info (struct gdbarch *gdbarch,
 369                            struct language_arch_info *lai)
 370 {
 371   const struct builtin_type *builtin = builtin_type (gdbarch);
 372
 373   lai->string_char_type = builtin->builtin_char;
 374   lai->primitive_type_vector
 375     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 376                               struct type *);
 377   lai->primitive_type_vector [pascal_primitive_type_int]
 378     = builtin->builtin_int;
 379   lai->primitive_type_vector [pascal_primitive_type_long]
 380     = builtin->builtin_long;
 381   lai->primitive_type_vector [pascal_primitive_type_short]
 382     = builtin->builtin_short;
 383   lai->primitive_type_vector [pascal_primitive_type_char]
 384     = builtin->builtin_char;
 385   lai->primitive_type_vector [pascal_primitive_type_float]
 386     = builtin->builtin_float;
 387   lai->primitive_type_vector [pascal_primitive_type_double]
 388     = builtin->builtin_double;
 389   lai->primitive_type_vector [pascal_primitive_type_void]
 390     = builtin->builtin_void;
 391   lai->primitive_type_vector [pascal_primitive_type_long_long]
 392     = builtin->builtin_long_long;
 393   lai->primitive_type_vector [pascal_primitive_type_signed_char]
 394     = builtin->builtin_signed_char;
 395   lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 396     = builtin->builtin_unsigned_char;
 397   lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 398     = builtin->builtin_unsigned_short;
 399   lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 400     = builtin->builtin_unsigned_int;
 401   lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 402     = builtin->builtin_unsigned_long;
 403   lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 404     = builtin->builtin_unsigned_long_long;
 405   lai->primitive_type_vector [pascal_primitive_type_long_double]
 406     = builtin->builtin_long_double;
 407   lai->primitive_type_vector [pascal_primitive_type_complex]
 408     = builtin->builtin_complex;
 409   lai->primitive_type_vector [pascal_primitive_type_double_complex]
 410     = builtin->builtin_double_complex;
 411
 412   lai->bool_type_symbol = "boolean";
 413   lai->bool_type_default = builtin->builtin_bool;
 414 }
 415
 416 const struct language_defn pascal_language_defn =
 417 {
 418   "pascal",                     /* Language name */
 419   "Pascal",
 420   language_pascal,
 421   range_check_on,
 422   case_sensitive_on,
 423   array_row_major,
 424   macro_expansion_no,
 425   &exp_descriptor_standard,
 426   pascal_parse,
 427   pascal_error,
 428   null_post_parser,
 429   pascal_printchar,             /* Print a character constant */
 430   pascal_printstr,              /* Function to print string constant */
 431   pascal_emit_char,             /* Print a single char */
 432   pascal_print_type,            /* Print a type using appropriate syntax */
 433   pascal_print_typedef,         /* Print a typedef using appropriate syntax */
 434   pascal_val_print,             /* Print a value using appropriate syntax */
 435   pascal_value_print,           /* Print a top-level value */
 436   default_read_var_value,       /* la_read_var_value */
 437   NULL,                         /* Language specific skip_trampoline */
 438   "this",                       /* name_of_this */
 439   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 440   basic_lookup_transparent_type,/* lookup_transparent_type */
 441   NULL,                         /* Language specific symbol demangler */
 442   NULL,                         /* Language specific class_name_from_physname */
 443   pascal_op_print_tab,          /* expression operators for printing */
 444   1,                            /* c-style arrays */
 445   0,                            /* String lower bound */
 446   default_word_break_characters,
 447   default_make_symbol_completion_list,
 448   pascal_language_arch_info,
 449   default_print_array_index,
 450   default_pass_by_reference,
 451   default_get_string,
 452   NULL,                         /* la_get_symbol_name_cmp */
 453   iterate_over_symbols,
 454   &default_varobj_ops,
 455   LANG_MAGIC
 456 };
 457
 458 void
 459 _initialize_pascal_language (void)
 460 {
 461   add_language (&pascal_language_defn);
 462 }