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
   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 1 if the type is a known pascal 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           if (length_pos)
 130             *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 131           if (length_size)
 132             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 1));
 133           if (string_pos)
 134             *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
 135           /* FIXME: how can I detect wide chars in GPC ?? */
 136           if (char_size)
 137             *char_size = 1;
 138           if (arrayname)
 139             *arrayname = TYPE_FIELDS (type)[2].name;
 140          return 3;
 141         };
 142     }
 143   return 0;
 144 }
 145
 146 static void pascal_one_char (int, struct ui_file *, int *);
 147
 148 /* Print the character C on STREAM as part of the contents of a literal
 149    string.
 150    In_quotes is reset to 0 if a char is written with #4 notation */
 151
 152 static void
 153 pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
 154 {
 155
 156   c &= 0xFF;                    /* Avoid sign bit follies */
 157
 158   if ((c == '\'') || (PRINT_LITERAL_FORM (c)))
 159     {
 160       if (!(*in_quotes))
 161         fputs_filtered ("'", stream);
 162       *in_quotes = 1;
 163       if (c == '\'')
 164         {
 165           fputs_filtered ("''", stream);
 166         }
 167       else
 168         fprintf_filtered (stream, "%c", c);
 169     }
 170   else
 171     {
 172       if (*in_quotes)
 173         fputs_filtered ("'", stream);
 174       *in_quotes = 0;
 175       fprintf_filtered (stream, "#%d", (unsigned int) c);
 176     }
 177 }
 178
 179 static void pascal_emit_char (int c, struct ui_file *stream, int quoter);
 180
 181 /* Print the character C on STREAM as part of the contents of a literal
 182    string whose delimiter is QUOTER.  Note that that format for printing
 183    characters and strings is language specific. */
 184
 185 static void
 186 pascal_emit_char (int c, struct ui_file *stream, int quoter)
 187 {
 188   int in_quotes = 0;
 189   pascal_one_char (c, stream, &in_quotes);
 190   if (in_quotes)
 191     fputs_filtered ("'", stream);
 192 }
 193
 194 void
 195 pascal_printchar (int c, struct ui_file *stream)
 196 {
 197   int in_quotes = 0;
 198   pascal_one_char (c, stream, &in_quotes);
 199   if (in_quotes)
 200     fputs_filtered ("'", stream);
 201 }
 202
 203 /* Print the character string STRING, printing at most LENGTH characters.
 204    Printing stops early if the number hits print_max; repeat counts
 205    are printed as appropriate.  Print ellipses at the end if we
 206    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.  */
 207
 208 void
 209 pascal_printstr (struct ui_file *stream, const gdb_byte *string,
 210                  unsigned int length, int width, int force_ellipses)
 211 {
 212   unsigned int i;
 213   unsigned int things_printed = 0;
 214   int in_quotes = 0;
 215   int need_comma = 0;
 216
 217   /* If the string was not truncated due to `set print elements', and
 218      the last byte of it is a null, we don't print that, in traditional C
 219      style.  */
 220   if ((!force_ellipses) && length > 0 && string[length - 1] == '\0')
 221     length--;
 222
 223   if (length == 0)
 224     {
 225       fputs_filtered ("''", stream);
 226       return;
 227     }
 228
 229   for (i = 0; i < length && things_printed < print_max; ++i)
 230     {
 231       /* Position of the character we are examining
 232          to see whether it is repeated.  */
 233       unsigned int rep1;
 234       /* Number of repetitions we have detected so far.  */
 235       unsigned int reps;
 236
 237       QUIT;
 238
 239       if (need_comma)
 240         {
 241           fputs_filtered (", ", stream);
 242           need_comma = 0;
 243         }
 244
 245       rep1 = i + 1;
 246       reps = 1;
 247       while (rep1 < length && string[rep1] == string[i])
 248         {
 249           ++rep1;
 250           ++reps;
 251         }
 252
 253       if (reps > repeat_count_threshold)
 254         {
 255           if (in_quotes)
 256             {
 257               if (inspect_it)
 258                 fputs_filtered ("\\', ", stream);
 259               else
 260                 fputs_filtered ("', ", stream);
 261               in_quotes = 0;
 262             }
 263           pascal_printchar (string[i], stream);
 264           fprintf_filtered (stream, " <repeats %u times>", reps);
 265           i = rep1 - 1;
 266           things_printed += repeat_count_threshold;
 267           need_comma = 1;
 268         }
 269       else
 270         {
 271           int c = string[i];
 272           if ((!in_quotes) && (PRINT_LITERAL_FORM (c)))
 273             {
 274               if (inspect_it)
 275                 fputs_filtered ("\\'", stream);
 276               else
 277                 fputs_filtered ("'", stream);
 278               in_quotes = 1;
 279             }
 280           pascal_one_char (c, stream, &in_quotes);
 281           ++things_printed;
 282         }
 283     }
 284
 285   /* Terminate the quotes if necessary.  */
 286   if (in_quotes)
 287     {
 288       if (inspect_it)
 289         fputs_filtered ("\\'", stream);
 290       else
 291         fputs_filtered ("'", stream);
 292     }
 293
 294   if (force_ellipses || i < length)
 295     fputs_filtered ("...", stream);
 296 }
 297 \f
 298
 299 /* Table mapping opcodes into strings for printing operators
 300    and precedences of the operators.  */
 301
 302 const struct op_print pascal_op_print_tab[] =
 303 {
 304   {",", BINOP_COMMA, PREC_COMMA, 0},
 305   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 306   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 307   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 308   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 309   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 310   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 311   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 312   {">=", BINOP_GEQ, PREC_ORDER, 0},
 313   {">", BINOP_GTR, PREC_ORDER, 0},
 314   {"<", BINOP_LESS, PREC_ORDER, 0},
 315   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 316   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 317   {"+", BINOP_ADD, PREC_ADD, 0},
 318   {"-", BINOP_SUB, PREC_ADD, 0},
 319   {"*", BINOP_MUL, PREC_MUL, 0},
 320   {"/", BINOP_DIV, PREC_MUL, 0},
 321   {"div", BINOP_INTDIV, PREC_MUL, 0},
 322   {"mod", BINOP_REM, PREC_MUL, 0},
 323   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 324   {"-", UNOP_NEG, PREC_PREFIX, 0},
 325   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 326   {"^", UNOP_IND, PREC_SUFFIX, 1},
 327   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 328   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 329   {NULL, 0, 0, 0}
 330 };
 331 \f
 332 enum pascal_primitive_types {
 333   pascal_primitive_type_int,
 334   pascal_primitive_type_long,
 335   pascal_primitive_type_short,
 336   pascal_primitive_type_char,
 337   pascal_primitive_type_float,
 338   pascal_primitive_type_double,
 339   pascal_primitive_type_void,
 340   pascal_primitive_type_long_long,
 341   pascal_primitive_type_signed_char,
 342   pascal_primitive_type_unsigned_char,
 343   pascal_primitive_type_unsigned_short,
 344   pascal_primitive_type_unsigned_int,
 345   pascal_primitive_type_unsigned_long,
 346   pascal_primitive_type_unsigned_long_long,
 347   pascal_primitive_type_long_double,
 348   pascal_primitive_type_complex,
 349   pascal_primitive_type_double_complex,
 350   nr_pascal_primitive_types
 351 };
 352
 353 static void
 354 pascal_language_arch_info (struct gdbarch *gdbarch,
 355                            struct language_arch_info *lai)
 356 {
 357   const struct builtin_type *builtin = builtin_type (gdbarch);
 358   lai->string_char_type = builtin->builtin_char;
 359   lai->primitive_type_vector
 360     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 361                               struct type *);
 362   lai->primitive_type_vector [pascal_primitive_type_int]
 363     = builtin->builtin_int;
 364   lai->primitive_type_vector [pascal_primitive_type_long]
 365     = builtin->builtin_long;
 366   lai->primitive_type_vector [pascal_primitive_type_short]
 367     = builtin->builtin_short;
 368   lai->primitive_type_vector [pascal_primitive_type_char]
 369     = builtin->builtin_char;
 370   lai->primitive_type_vector [pascal_primitive_type_float]
 371     = builtin->builtin_float;
 372   lai->primitive_type_vector [pascal_primitive_type_double]
 373     = builtin->builtin_double;
 374   lai->primitive_type_vector [pascal_primitive_type_void]
 375     = builtin->builtin_void;
 376   lai->primitive_type_vector [pascal_primitive_type_long_long]
 377     = builtin->builtin_long_long;
 378   lai->primitive_type_vector [pascal_primitive_type_signed_char]
 379     = builtin->builtin_signed_char;
 380   lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 381     = builtin->builtin_unsigned_char;
 382   lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 383     = builtin->builtin_unsigned_short;
 384   lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 385     = builtin->builtin_unsigned_int;
 386   lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 387     = builtin->builtin_unsigned_long;
 388   lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 389     = builtin->builtin_unsigned_long_long;
 390   lai->primitive_type_vector [pascal_primitive_type_long_double]
 391     = builtin->builtin_long_double;
 392   lai->primitive_type_vector [pascal_primitive_type_complex]
 393     = builtin->builtin_complex;
 394   lai->primitive_type_vector [pascal_primitive_type_double_complex]
 395     = builtin->builtin_double_complex;
 396 }
 397
 398 const struct language_defn pascal_language_defn =
 399 {
 400   "pascal",                     /* Language name */
 401   language_pascal,
 402   range_check_on,
 403   type_check_on,
 404   case_sensitive_on,
 405   array_row_major,
 406   &exp_descriptor_standard,
 407   pascal_parse,
 408   pascal_error,
 409   null_post_parser,
 410   pascal_printchar,             /* Print a character constant */
 411   pascal_printstr,              /* Function to print string constant */
 412   pascal_emit_char,             /* Print a single char */
 413   pascal_print_type,            /* Print a type using appropriate syntax */
 414   pascal_val_print,             /* Print a value using appropriate syntax */
 415   pascal_value_print,           /* Print a top-level value */
 416   NULL,                         /* Language specific skip_trampoline */
 417   value_of_this,                /* value_of_this */
 418   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 419   basic_lookup_transparent_type,/* lookup_transparent_type */
 420   NULL,                         /* Language specific symbol demangler */
 421   NULL,                         /* Language specific class_name_from_physname */
 422   pascal_op_print_tab,          /* expression operators for printing */
 423   1,                            /* c-style arrays */
 424   0,                            /* String lower bound */
 425   default_word_break_characters,
 426   pascal_language_arch_info,
 427   default_print_array_index,
 428   default_pass_by_reference,
 429   LANG_MAGIC
 430 };
 431
 432 void
 433 _initialize_pascal_language (void)
 434 {
 435   add_language (&pascal_language_defn);
 436 }