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               if (TYPE_CODE (*char_type) == TYPE_CODE_ARRAY)
 141                 *char_type = TYPE_TARGET_TYPE (*char_type);
 142             }
 143           if (arrayname)
 144             *arrayname = TYPE_FIELDS (type)[2].name;
 145          return 3;
 146         };
 147     }
 148   return 0;
 149 }
 150
 151 static void pascal_one_char (int, struct ui_file *, int *);
 152
 153 /* Print the character C on STREAM as part of the contents of a literal
 154    string.
 155    In_quotes is reset to 0 if a char is written with #4 notation */
 156
 157 static void
 158 pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
 159 {
 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   pascal_one_char (c, stream, &in_quotes);
 194   if (in_quotes)
 195     fputs_filtered ("'", stream);
 196 }
 197
 198 void
 199 pascal_printchar (int c, struct type *type, struct ui_file *stream)
 200 {
 201   int in_quotes = 0;
 202   pascal_one_char (c, stream, &in_quotes);
 203   if (in_quotes)
 204     fputs_filtered ("'", stream);
 205 }
 206
 207 /* Print the character string STRING, printing at most LENGTH characters.
 208    Printing stops early if the number hits print_max; repeat counts
 209    are printed as appropriate.  Print ellipses at the end if we
 210    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.  */
 211
 212 void
 213 pascal_printstr (struct ui_file *stream, struct type *type,
 214                  const gdb_byte *string, unsigned int length,
 215                  const char *encoding, int force_ellipses,
 216                  const struct value_print_options *options)
 217 {
 218   enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
 219   unsigned int i;
 220   unsigned int things_printed = 0;
 221   int in_quotes = 0;
 222   int need_comma = 0;
 223   int width = TYPE_LENGTH (type);
 224
 225   /* If the string was not truncated due to `set print elements', and
 226      the last byte of it is a null, we don't print that, in traditional C
 227      style.  */
 228   if ((!force_ellipses) && length > 0
 229         && extract_unsigned_integer (string + (length - 1) * width, width,
 230                                      byte_order) == 0)
 231     length--;
 232
 233   if (length == 0)
 234     {
 235       fputs_filtered ("''", stream);
 236       return;
 237     }
 238
 239   for (i = 0; i < length && things_printed < options->print_max; ++i)
 240     {
 241       /* Position of the character we are examining
 242          to see whether it is repeated.  */
 243       unsigned int rep1;
 244       /* Number of repetitions we have detected so far.  */
 245       unsigned int reps;
 246       unsigned long int current_char;
 247
 248       QUIT;
 249
 250       if (need_comma)
 251         {
 252           fputs_filtered (", ", stream);
 253           need_comma = 0;
 254         }
 255
 256       current_char = extract_unsigned_integer (string + i * width, width,
 257                                                byte_order);
 258
 259       rep1 = i + 1;
 260       reps = 1;
 261       while (rep1 < length
 262              && extract_unsigned_integer (string + rep1 * width, width,
 263                                           byte_order) == current_char)
 264         {
 265           ++rep1;
 266           ++reps;
 267         }
 268
 269       if (reps > options->repeat_count_threshold)
 270         {
 271           if (in_quotes)
 272             {
 273               if (options->inspect_it)
 274                 fputs_filtered ("\\', ", stream);
 275               else
 276                 fputs_filtered ("', ", stream);
 277               in_quotes = 0;
 278             }
 279           pascal_printchar (current_char, type, stream);
 280           fprintf_filtered (stream, " <repeats %u times>", reps);
 281           i = rep1 - 1;
 282           things_printed += options->repeat_count_threshold;
 283           need_comma = 1;
 284         }
 285       else
 286         {
 287           if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 288             {
 289               if (options->inspect_it)
 290                 fputs_filtered ("\\'", stream);
 291               else
 292                 fputs_filtered ("'", stream);
 293               in_quotes = 1;
 294             }
 295           pascal_one_char (current_char, stream, &in_quotes);
 296           ++things_printed;
 297         }
 298     }
 299
 300   /* Terminate the quotes if necessary.  */
 301   if (in_quotes)
 302     {
 303       if (options->inspect_it)
 304         fputs_filtered ("\\'", stream);
 305       else
 306         fputs_filtered ("'", stream);
 307     }
 308
 309   if (force_ellipses || i < length)
 310     fputs_filtered ("...", stream);
 311 }
 312 \f
 313
 314 /* Table mapping opcodes into strings for printing operators
 315    and precedences of the operators.  */
 316
 317 const struct op_print pascal_op_print_tab[] =
 318 {
 319   {",", BINOP_COMMA, PREC_COMMA, 0},
 320   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 321   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 322   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 323   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 324   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 325   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 326   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 327   {">=", BINOP_GEQ, PREC_ORDER, 0},
 328   {">", BINOP_GTR, PREC_ORDER, 0},
 329   {"<", BINOP_LESS, PREC_ORDER, 0},
 330   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 331   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 332   {"+", BINOP_ADD, PREC_ADD, 0},
 333   {"-", BINOP_SUB, PREC_ADD, 0},
 334   {"*", BINOP_MUL, PREC_MUL, 0},
 335   {"/", BINOP_DIV, PREC_MUL, 0},
 336   {"div", BINOP_INTDIV, PREC_MUL, 0},
 337   {"mod", BINOP_REM, PREC_MUL, 0},
 338   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 339   {"-", UNOP_NEG, PREC_PREFIX, 0},
 340   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 341   {"^", UNOP_IND, PREC_SUFFIX, 1},
 342   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 343   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 344   {NULL, 0, 0, 0}
 345 };
 346 \f
 347 enum pascal_primitive_types {
 348   pascal_primitive_type_int,
 349   pascal_primitive_type_long,
 350   pascal_primitive_type_short,
 351   pascal_primitive_type_char,
 352   pascal_primitive_type_float,
 353   pascal_primitive_type_double,
 354   pascal_primitive_type_void,
 355   pascal_primitive_type_long_long,
 356   pascal_primitive_type_signed_char,
 357   pascal_primitive_type_unsigned_char,
 358   pascal_primitive_type_unsigned_short,
 359   pascal_primitive_type_unsigned_int,
 360   pascal_primitive_type_unsigned_long,
 361   pascal_primitive_type_unsigned_long_long,
 362   pascal_primitive_type_long_double,
 363   pascal_primitive_type_complex,
 364   pascal_primitive_type_double_complex,
 365   nr_pascal_primitive_types
 366 };
 367
 368 static void
 369 pascal_language_arch_info (struct gdbarch *gdbarch,
 370                            struct language_arch_info *lai)
 371 {
 372   const struct builtin_type *builtin = builtin_type (gdbarch);
 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   language_pascal,
 420   range_check_on,
 421   type_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   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   LANG_MAGIC
 452 };
 453
 454 void
 455 _initialize_pascal_language (void)
 456 {
 457   add_language (&pascal_language_defn);
 458 }