gdb/p-lang.c

   1 /* Pascal language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
   4    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 /* This file is derived from c-lang.c */
  22
  23 #include "defs.h"
  24 #include "gdb_string.h"
  25 #include "symtab.h"
  26 #include "gdbtypes.h"
  27 #include "expression.h"
  28 #include "parser-defs.h"
  29 #include "language.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                        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           && strcmp (TYPE_FIELDS (type)[0].name, "length") == 0
 110           && strcmp (TYPE_FIELDS (type)[1].name, "st") == 0)
 111         {
 112           if (length_pos)
 113             *length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
 114           if (length_size)
 115             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0));
 116           if (string_pos)
 117             *string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 118           if (char_type)
 119             *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 1));
 120           if (arrayname)
 121             *arrayname = TYPE_FIELDS (type)[1].name;
 122          return 2;
 123         };
 124       /* GNU pascal strings.  */
 125       /* Three fields: Capacity, length and schema$ or _p_schema.  */
 126       if (TYPE_NFIELDS (type) == 3
 127           && strcmp (TYPE_FIELDS (type)[0].name, "Capacity") == 0
 128           && strcmp (TYPE_FIELDS (type)[1].name, "length") == 0)
 129         {
 130           if (length_pos)
 131             *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 132           if (length_size)
 133             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 1));
 134           if (string_pos)
 135             *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
 136           /* FIXME: how can I detect wide chars in GPC ?? */
 137           if (char_type)
 138             {
 139               *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 2));
 140
 141               if (TYPE_CODE (*char_type) == TYPE_CODE_ARRAY)
 142                 *char_type = TYPE_TARGET_TYPE (*char_type);
 143             }
 144           if (arrayname)
 145             *arrayname = TYPE_FIELDS (type)[2].name;
 146          return 3;
 147         };
 148     }
 149   return 0;
 150 }
 151
 152 static void pascal_one_char (int, struct ui_file *, int *);
 153
 154 /* Print the character C on STREAM as part of the contents of a literal
 155    string.
 156    In_quotes is reset to 0 if a char is written with #4 notation */
 157
 158 static void
 159 pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
 160 {
 161   if (c == '\'' || ((unsigned int) c <= 0xff && (PRINT_LITERAL_FORM (c))))
 162     {
 163       if (!(*in_quotes))
 164         fputs_filtered ("'", stream);
 165       *in_quotes = 1;
 166       if (c == '\'')
 167         {
 168           fputs_filtered ("''", stream);
 169         }
 170       else
 171         fprintf_filtered (stream, "%c", c);
 172     }
 173   else
 174     {
 175       if (*in_quotes)
 176         fputs_filtered ("'", stream);
 177       *in_quotes = 0;
 178       fprintf_filtered (stream, "#%d", (unsigned int) c);
 179     }
 180 }
 181
 182 static void pascal_emit_char (int c, struct type *type,
 183                               struct ui_file *stream, int quoter);
 184
 185 /* Print the character C on STREAM as part of the contents of a literal
 186    string whose delimiter is QUOTER.  Note that that format for printing
 187    characters and strings is language specific. */
 188
 189 static void
 190 pascal_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
 191 {
 192   int in_quotes = 0;
 193
 194   pascal_one_char (c, stream, &in_quotes);
 195   if (in_quotes)
 196     fputs_filtered ("'", stream);
 197 }
 198
 199 void
 200 pascal_printchar (int c, struct type *type, struct ui_file *stream)
 201 {
 202   int in_quotes = 0;
 203
 204   pascal_one_char (c, stream, &in_quotes);
 205   if (in_quotes)
 206     fputs_filtered ("'", stream);
 207 }
 208
 209 /* Print the character string STRING, printing at most LENGTH characters.
 210    Printing stops early if the number hits print_max; repeat counts
 211    are printed as appropriate.  Print ellipses at the end if we
 212    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.  */
 213
 214 void
 215 pascal_printstr (struct ui_file *stream, struct type *type,
 216                  const gdb_byte *string, unsigned int length,
 217                  const char *encoding, int force_ellipses,
 218                  const struct value_print_options *options)
 219 {
 220   enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
 221   unsigned int i;
 222   unsigned int things_printed = 0;
 223   int in_quotes = 0;
 224   int need_comma = 0;
 225   int width;
 226
 227   /* Preserve TYPE's original type, just set its LENGTH.  */
 228   check_typedef (type);
 229   width = TYPE_LENGTH (type);
 230
 231   /* If the string was not truncated due to `set print elements', and
 232      the last byte of it is a null, we don't print that, in traditional C
 233      style.  */
 234   if ((!force_ellipses) && length > 0
 235         && extract_unsigned_integer (string + (length - 1) * width, width,
 236                                      byte_order) == 0)
 237     length--;
 238
 239   if (length == 0)
 240     {
 241       fputs_filtered ("''", stream);
 242       return;
 243     }
 244
 245   for (i = 0; i < length && things_printed < options->print_max; ++i)
 246     {
 247       /* Position of the character we are examining
 248          to see whether it is repeated.  */
 249       unsigned int rep1;
 250       /* Number of repetitions we have detected so far.  */
 251       unsigned int reps;
 252       unsigned long int current_char;
 253
 254       QUIT;
 255
 256       if (need_comma)
 257         {
 258           fputs_filtered (", ", stream);
 259           need_comma = 0;
 260         }
 261
 262       current_char = extract_unsigned_integer (string + i * width, width,
 263                                                byte_order);
 264
 265       rep1 = i + 1;
 266       reps = 1;
 267       while (rep1 < length
 268              && extract_unsigned_integer (string + rep1 * width, width,
 269                                           byte_order) == current_char)
 270         {
 271           ++rep1;
 272           ++reps;
 273         }
 274
 275       if (reps > options->repeat_count_threshold)
 276         {
 277           if (in_quotes)
 278             {
 279               if (options->inspect_it)
 280                 fputs_filtered ("\\', ", stream);
 281               else
 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               if (options->inspect_it)
 296                 fputs_filtered ("\\'", stream);
 297               else
 298                 fputs_filtered ("'", stream);
 299               in_quotes = 1;
 300             }
 301           pascal_one_char (current_char, stream, &in_quotes);
 302           ++things_printed;
 303         }
 304     }
 305
 306   /* Terminate the quotes if necessary.  */
 307   if (in_quotes)
 308     {
 309       if (options->inspect_it)
 310         fputs_filtered ("\\'", stream);
 311       else
 312         fputs_filtered ("'", stream);
 313     }
 314
 315   if (force_ellipses || i < length)
 316     fputs_filtered ("...", stream);
 317 }
 318 \f
 319
 320 /* Table mapping opcodes into strings for printing operators
 321    and precedences of the operators.  */
 322
 323 const struct op_print pascal_op_print_tab[] =
 324 {
 325   {",", BINOP_COMMA, PREC_COMMA, 0},
 326   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 327   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 328   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 329   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 330   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 331   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 332   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 333   {">=", BINOP_GEQ, PREC_ORDER, 0},
 334   {">", BINOP_GTR, PREC_ORDER, 0},
 335   {"<", BINOP_LESS, PREC_ORDER, 0},
 336   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 337   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 338   {"+", BINOP_ADD, PREC_ADD, 0},
 339   {"-", BINOP_SUB, PREC_ADD, 0},
 340   {"*", BINOP_MUL, PREC_MUL, 0},
 341   {"/", BINOP_DIV, PREC_MUL, 0},
 342   {"div", BINOP_INTDIV, PREC_MUL, 0},
 343   {"mod", BINOP_REM, PREC_MUL, 0},
 344   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 345   {"-", UNOP_NEG, PREC_PREFIX, 0},
 346   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 347   {"^", UNOP_IND, PREC_SUFFIX, 1},
 348   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 349   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 350   {NULL, 0, 0, 0}
 351 };
 352 \f
 353 enum pascal_primitive_types {
 354   pascal_primitive_type_int,
 355   pascal_primitive_type_long,
 356   pascal_primitive_type_short,
 357   pascal_primitive_type_char,
 358   pascal_primitive_type_float,
 359   pascal_primitive_type_double,
 360   pascal_primitive_type_void,
 361   pascal_primitive_type_long_long,
 362   pascal_primitive_type_signed_char,
 363   pascal_primitive_type_unsigned_char,
 364   pascal_primitive_type_unsigned_short,
 365   pascal_primitive_type_unsigned_int,
 366   pascal_primitive_type_unsigned_long,
 367   pascal_primitive_type_unsigned_long_long,
 368   pascal_primitive_type_long_double,
 369   pascal_primitive_type_complex,
 370   pascal_primitive_type_double_complex,
 371   nr_pascal_primitive_types
 372 };
 373
 374 static void
 375 pascal_language_arch_info (struct gdbarch *gdbarch,
 376                            struct language_arch_info *lai)
 377 {
 378   const struct builtin_type *builtin = builtin_type (gdbarch);
 379
 380   lai->string_char_type = builtin->builtin_char;
 381   lai->primitive_type_vector
 382     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 383                               struct type *);
 384   lai->primitive_type_vector [pascal_primitive_type_int]
 385     = builtin->builtin_int;
 386   lai->primitive_type_vector [pascal_primitive_type_long]
 387     = builtin->builtin_long;
 388   lai->primitive_type_vector [pascal_primitive_type_short]
 389     = builtin->builtin_short;
 390   lai->primitive_type_vector [pascal_primitive_type_char]
 391     = builtin->builtin_char;
 392   lai->primitive_type_vector [pascal_primitive_type_float]
 393     = builtin->builtin_float;
 394   lai->primitive_type_vector [pascal_primitive_type_double]
 395     = builtin->builtin_double;
 396   lai->primitive_type_vector [pascal_primitive_type_void]
 397     = builtin->builtin_void;
 398   lai->primitive_type_vector [pascal_primitive_type_long_long]
 399     = builtin->builtin_long_long;
 400   lai->primitive_type_vector [pascal_primitive_type_signed_char]
 401     = builtin->builtin_signed_char;
 402   lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 403     = builtin->builtin_unsigned_char;
 404   lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 405     = builtin->builtin_unsigned_short;
 406   lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 407     = builtin->builtin_unsigned_int;
 408   lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 409     = builtin->builtin_unsigned_long;
 410   lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 411     = builtin->builtin_unsigned_long_long;
 412   lai->primitive_type_vector [pascal_primitive_type_long_double]
 413     = builtin->builtin_long_double;
 414   lai->primitive_type_vector [pascal_primitive_type_complex]
 415     = builtin->builtin_complex;
 416   lai->primitive_type_vector [pascal_primitive_type_double_complex]
 417     = builtin->builtin_double_complex;
 418
 419   lai->bool_type_symbol = "boolean";
 420   lai->bool_type_default = builtin->builtin_bool;
 421 }
 422
 423 const struct language_defn pascal_language_defn =
 424 {
 425   "pascal",                     /* Language name */
 426   language_pascal,
 427   range_check_on,
 428   type_check_on,
 429   case_sensitive_on,
 430   array_row_major,
 431   macro_expansion_no,
 432   &exp_descriptor_standard,
 433   pascal_parse,
 434   pascal_error,
 435   null_post_parser,
 436   pascal_printchar,             /* Print a character constant */
 437   pascal_printstr,              /* Function to print string constant */
 438   pascal_emit_char,             /* Print a single char */
 439   pascal_print_type,            /* Print a type using appropriate syntax */
 440   pascal_print_typedef,         /* Print a typedef using appropriate syntax */
 441   pascal_val_print,             /* Print a value using appropriate syntax */
 442   pascal_value_print,           /* Print a top-level value */
 443   NULL,                         /* Language specific skip_trampoline */
 444   "this",                       /* name_of_this */
 445   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 446   basic_lookup_transparent_type,/* lookup_transparent_type */
 447   NULL,                         /* Language specific symbol demangler */
 448   NULL,                         /* Language specific class_name_from_physname */
 449   pascal_op_print_tab,          /* expression operators for printing */
 450   1,                            /* c-style arrays */
 451   0,                            /* String lower bound */
 452   default_word_break_characters,
 453   default_make_symbol_completion_list,
 454   pascal_language_arch_info,
 455   default_print_array_index,
 456   default_pass_by_reference,
 457   default_get_string,
 458   LANG_MAGIC
 459 };
 460
 461 void
 462 _initialize_pascal_language (void)
 463 {
 464   add_language (&pascal_language_defn);
 465 }