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
   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, int *char_size,
 101                        char **arrayname)
 102 {
 103   if (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           && strcmp (TYPE_FIELDS (type)[0].name, "length") == 0
 109           && strcmp (TYPE_FIELDS (type)[1].name, "st") == 0)
 110         {
 111           if (length_pos)
 112             *length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
 113           if (length_size)
 114             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0));
 115           if (string_pos)
 116             *string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 117           if (char_size)
 118             *char_size = 1;
 119           if (arrayname)
 120             *arrayname = TYPE_FIELDS (type)[1].name;
 121          return 2;
 122         };
 123       /* GNU pascal strings.  */
 124       /* Three fields: Capacity, length and schema$ or _p_schema.  */
 125       if (TYPE_NFIELDS (type) == 3
 126           && strcmp (TYPE_FIELDS (type)[0].name, "Capacity") == 0
 127           && strcmp (TYPE_FIELDS (type)[1].name, "length") == 0)
 128         {
 129           struct type *char_type;
 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           char_type = TYPE_FIELD_TYPE (type,2);
 138           if (char_size && TYPE_CODE (char_type) == TYPE_CODE_ARRAY)
 139             {
 140               *char_size = TYPE_LENGTH (TYPE_TARGET_TYPE (char_type));
 141             }
 142           else if (char_size)
 143             *char_size = 1;
 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
 162   c &= 0xFF;                    /* Avoid sign bit follies */
 163
 164   if ((c == '\'') || (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 ui_file *stream, int quoter);
 186
 187 /* Print the character C on STREAM as part of the contents of a literal
 188    string whose delimiter is QUOTER.  Note that that format for printing
 189    characters and strings is language specific. */
 190
 191 static void
 192 pascal_emit_char (int c, struct ui_file *stream, int quoter)
 193 {
 194   int in_quotes = 0;
 195   pascal_one_char (c, stream, &in_quotes);
 196   if (in_quotes)
 197     fputs_filtered ("'", stream);
 198 }
 199
 200 void
 201 pascal_printchar (int c, struct ui_file *stream)
 202 {
 203   int in_quotes = 0;
 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, const gdb_byte *string,
 216                  unsigned int length, int width, int force_ellipses,
 217                  const struct value_print_options *options)
 218 {
 219   unsigned int i;
 220   unsigned int things_printed = 0;
 221   int in_quotes = 0;
 222   int need_comma = 0;
 223
 224   /* If the string was not truncated due to `set print elements', and
 225      the last byte of it is a null, we don't print that, in traditional C
 226      style.  */
 227   if ((!force_ellipses) && length > 0
 228         && extract_unsigned_integer (string + (length - 1) * width, width) == 0)
 229     length--;
 230
 231   if (length == 0)
 232     {
 233       fputs_filtered ("''", stream);
 234       return;
 235     }
 236
 237   for (i = 0; i < length && things_printed < options->print_max; ++i)
 238     {
 239       /* Position of the character we are examining
 240          to see whether it is repeated.  */
 241       unsigned int rep1;
 242       /* Number of repetitions we have detected so far.  */
 243       unsigned int reps;
 244       unsigned long int current_char;
 245
 246       QUIT;
 247
 248       if (need_comma)
 249         {
 250           fputs_filtered (", ", stream);
 251           need_comma = 0;
 252         }
 253
 254       current_char = extract_unsigned_integer (string + i * width, width);
 255
 256       rep1 = i + 1;
 257       reps = 1;
 258       while (rep1 < length
 259              && extract_unsigned_integer (string + rep1 * width, width)
 260                 == current_char)
 261         {
 262           ++rep1;
 263           ++reps;
 264         }
 265
 266       if (reps > options->repeat_count_threshold)
 267         {
 268           if (in_quotes)
 269             {
 270               if (options->inspect_it)
 271                 fputs_filtered ("\\', ", stream);
 272               else
 273                 fputs_filtered ("', ", stream);
 274               in_quotes = 0;
 275             }
 276           pascal_printchar (current_char, stream);
 277           fprintf_filtered (stream, " <repeats %u times>", reps);
 278           i = rep1 - 1;
 279           things_printed += options->repeat_count_threshold;
 280           need_comma = 1;
 281         }
 282       else
 283         {
 284           if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 285             {
 286               if (options->inspect_it)
 287                 fputs_filtered ("\\'", stream);
 288               else
 289                 fputs_filtered ("'", stream);
 290               in_quotes = 1;
 291             }
 292           pascal_one_char (current_char, stream, &in_quotes);
 293           ++things_printed;
 294         }
 295     }
 296
 297   /* Terminate the quotes if necessary.  */
 298   if (in_quotes)
 299     {
 300       if (options->inspect_it)
 301         fputs_filtered ("\\'", stream);
 302       else
 303         fputs_filtered ("'", stream);
 304     }
 305
 306   if (force_ellipses || i < length)
 307     fputs_filtered ("...", stream);
 308 }
 309 \f
 310
 311 /* Table mapping opcodes into strings for printing operators
 312    and precedences of the operators.  */
 313
 314 const struct op_print pascal_op_print_tab[] =
 315 {
 316   {",", BINOP_COMMA, PREC_COMMA, 0},
 317   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 318   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 319   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 320   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 321   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 322   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 323   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 324   {">=", BINOP_GEQ, PREC_ORDER, 0},
 325   {">", BINOP_GTR, PREC_ORDER, 0},
 326   {"<", BINOP_LESS, PREC_ORDER, 0},
 327   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 328   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 329   {"+", BINOP_ADD, PREC_ADD, 0},
 330   {"-", BINOP_SUB, PREC_ADD, 0},
 331   {"*", BINOP_MUL, PREC_MUL, 0},
 332   {"/", BINOP_DIV, PREC_MUL, 0},
 333   {"div", BINOP_INTDIV, PREC_MUL, 0},
 334   {"mod", BINOP_REM, PREC_MUL, 0},
 335   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 336   {"-", UNOP_NEG, PREC_PREFIX, 0},
 337   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 338   {"^", UNOP_IND, PREC_SUFFIX, 1},
 339   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 340   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 341   {NULL, 0, 0, 0}
 342 };
 343 \f
 344 enum pascal_primitive_types {
 345   pascal_primitive_type_int,
 346   pascal_primitive_type_long,
 347   pascal_primitive_type_short,
 348   pascal_primitive_type_char,
 349   pascal_primitive_type_float,
 350   pascal_primitive_type_double,
 351   pascal_primitive_type_void,
 352   pascal_primitive_type_long_long,
 353   pascal_primitive_type_signed_char,
 354   pascal_primitive_type_unsigned_char,
 355   pascal_primitive_type_unsigned_short,
 356   pascal_primitive_type_unsigned_int,
 357   pascal_primitive_type_unsigned_long,
 358   pascal_primitive_type_unsigned_long_long,
 359   pascal_primitive_type_long_double,
 360   pascal_primitive_type_complex,
 361   pascal_primitive_type_double_complex,
 362   nr_pascal_primitive_types
 363 };
 364
 365 static void
 366 pascal_language_arch_info (struct gdbarch *gdbarch,
 367                            struct language_arch_info *lai)
 368 {
 369   const struct builtin_type *builtin = builtin_type (gdbarch);
 370   lai->string_char_type = builtin->builtin_char;
 371   lai->primitive_type_vector
 372     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 373                               struct type *);
 374   lai->primitive_type_vector [pascal_primitive_type_int]
 375     = builtin->builtin_int;
 376   lai->primitive_type_vector [pascal_primitive_type_long]
 377     = builtin->builtin_long;
 378   lai->primitive_type_vector [pascal_primitive_type_short]
 379     = builtin->builtin_short;
 380   lai->primitive_type_vector [pascal_primitive_type_char]
 381     = builtin->builtin_char;
 382   lai->primitive_type_vector [pascal_primitive_type_float]
 383     = builtin->builtin_float;
 384   lai->primitive_type_vector [pascal_primitive_type_double]
 385     = builtin->builtin_double;
 386   lai->primitive_type_vector [pascal_primitive_type_void]
 387     = builtin->builtin_void;
 388   lai->primitive_type_vector [pascal_primitive_type_long_long]
 389     = builtin->builtin_long_long;
 390   lai->primitive_type_vector [pascal_primitive_type_signed_char]
 391     = builtin->builtin_signed_char;
 392   lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 393     = builtin->builtin_unsigned_char;
 394   lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 395     = builtin->builtin_unsigned_short;
 396   lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 397     = builtin->builtin_unsigned_int;
 398   lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 399     = builtin->builtin_unsigned_long;
 400   lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 401     = builtin->builtin_unsigned_long_long;
 402   lai->primitive_type_vector [pascal_primitive_type_long_double]
 403     = builtin->builtin_long_double;
 404   lai->primitive_type_vector [pascal_primitive_type_complex]
 405     = builtin->builtin_complex;
 406   lai->primitive_type_vector [pascal_primitive_type_double_complex]
 407     = builtin->builtin_double_complex;
 408
 409   lai->bool_type_symbol = "boolean";
 410   lai->bool_type_default = builtin->builtin_bool;
 411 }
 412
 413 const struct language_defn pascal_language_defn =
 414 {
 415   "pascal",                     /* Language name */
 416   language_pascal,
 417   range_check_on,
 418   type_check_on,
 419   case_sensitive_on,
 420   array_row_major,
 421   macro_expansion_no,
 422   &exp_descriptor_standard,
 423   pascal_parse,
 424   pascal_error,
 425   null_post_parser,
 426   pascal_printchar,             /* Print a character constant */
 427   pascal_printstr,              /* Function to print string constant */
 428   pascal_emit_char,             /* Print a single char */
 429   pascal_print_type,            /* Print a type using appropriate syntax */
 430   pascal_print_typedef,         /* Print a typedef using appropriate syntax */
 431   pascal_val_print,             /* Print a value using appropriate syntax */
 432   pascal_value_print,           /* Print a top-level value */
 433   NULL,                         /* Language specific skip_trampoline */
 434   "this",                       /* name_of_this */
 435   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 436   basic_lookup_transparent_type,/* lookup_transparent_type */
 437   NULL,                         /* Language specific symbol demangler */
 438   NULL,                         /* Language specific class_name_from_physname */
 439   pascal_op_print_tab,          /* expression operators for printing */
 440   1,                            /* c-style arrays */
 441   0,                            /* String lower bound */
 442   default_word_break_characters,
 443   default_make_symbol_completion_list,
 444   pascal_language_arch_info,
 445   default_print_array_index,
 446   default_pass_by_reference,
 447   default_get_string,
 448   LANG_MAGIC
 449 };
 450
 451 void
 452 _initialize_pascal_language (void)
 453 {
 454   add_language (&pascal_language_defn);
 455 }