gdb/p-lang.c

   1 /* Pascal language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2020 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 "symtab.h"
  24 #include "gdbtypes.h"
  25 #include "expression.h"
  26 #include "parser-defs.h"
  27 #include "language.h"
  28 #include "varobj.h"
  29 #include "p-lang.h"
  30 #include "valprint.h"
  31 #include "value.h"
  32 #include <ctype.h>
  33 #include "c-lang.h"
  34 #include "gdbarch.h"
  35 #include "cli/cli-style.h"
  36
  37 /* All GPC versions until now (2007-09-27) also define a symbol called
  38    '_p_initialize'.  Check for the presence of this symbol first.  */
  39 static const char GPC_P_INITIALIZE[] = "_p_initialize";
  40
  41 /* The name of the symbol that GPC uses as the name of the main
  42    procedure (since version 20050212).  */
  43 static const char GPC_MAIN_PROGRAM_NAME_1[] = "_p__M0_main_program";
  44
  45 /* Older versions of GPC (versions older than 20050212) were using
  46    a different name for the main procedure.  */
  47 static const char GPC_MAIN_PROGRAM_NAME_2[] = "pascal_main_program";
  48
  49 /* Function returning the special symbol name used
  50    by GPC for the main procedure in the main program
  51    if it is found in minimal symbol list.
  52    This function tries to find minimal symbols generated by GPC
  53    so that it finds the even if the program was compiled
  54    without debugging information.
  55    According to information supplied by Waldeck Hebisch,
  56    this should work for all versions posterior to June 2000.  */
  57
  58 const char *
  59 pascal_main_name (void)
  60 {
  61   struct bound_minimal_symbol msym;
  62
  63   msym = lookup_minimal_symbol (GPC_P_INITIALIZE, NULL, NULL);
  64
  65   /*  If '_p_initialize' was not found, the main program is likely not
  66      written in Pascal.  */
  67   if (msym.minsym == NULL)
  68     return NULL;
  69
  70   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_1, NULL, NULL);
  71   if (msym.minsym != NULL)
  72     {
  73       return GPC_MAIN_PROGRAM_NAME_1;
  74     }
  75
  76   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_2, NULL, NULL);
  77   if (msym.minsym != NULL)
  78     {
  79       return GPC_MAIN_PROGRAM_NAME_2;
  80     }
  81
  82   /*  No known entry procedure found, the main program is probably
  83       not compiled with GPC.  */
  84   return NULL;
  85 }
  86
  87 /* Determines if type TYPE is a pascal string type.
  88    Returns a positive value if the type is a known pascal string type.
  89    This function is used by p-valprint.c code to allow better string display.
  90    If it is a pascal string type, then it also sets info needed
  91    to get the length and the data of the string
  92    length_pos, length_size and string_pos are given in bytes.
  93    char_size gives the element size in bytes.
  94    FIXME: if the position or the size of these fields
  95    are not multiple of TARGET_CHAR_BIT then the results are wrong
  96    but this does not happen for Free Pascal nor for GPC.  */
  97 int
  98 is_pascal_string_type (struct type *type,int *length_pos,
  99                        int *length_size, int *string_pos,
 100                        struct type **char_type,
 101                        const char **arrayname)
 102 {
 103   if (type != NULL && type->code () == TYPE_CODE_STRUCT)
 104     {
 105       /* Old Borland type pascal strings from Free Pascal Compiler.  */
 106       /* Two fields: length and st.  */
 107       if (type->num_fields () == 2
 108           && TYPE_FIELD_NAME (type, 0)
 109           && strcmp (TYPE_FIELD_NAME (type, 0), "length") == 0
 110           && TYPE_FIELD_NAME (type, 1)
 111           && strcmp (TYPE_FIELD_NAME (type, 1), "st") == 0)
 112         {
 113           if (length_pos)
 114             *length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
 115           if (length_size)
 116             *length_size = TYPE_LENGTH (type->field (0).type ());
 117           if (string_pos)
 118             *string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 119           if (char_type)
 120             *char_type = TYPE_TARGET_TYPE (type->field (1).type ());
 121           if (arrayname)
 122             *arrayname = TYPE_FIELD_NAME (type, 1);
 123          return 2;
 124         };
 125       /* GNU pascal strings.  */
 126       /* Three fields: Capacity, length and schema$ or _p_schema.  */
 127       if (type->num_fields () == 3
 128           && TYPE_FIELD_NAME (type, 0)
 129           && strcmp (TYPE_FIELD_NAME (type, 0), "Capacity") == 0
 130           && TYPE_FIELD_NAME (type, 1)
 131           && strcmp (TYPE_FIELD_NAME (type, 1), "length") == 0)
 132         {
 133           if (length_pos)
 134             *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 135           if (length_size)
 136             *length_size = TYPE_LENGTH (type->field (1).type ());
 137           if (string_pos)
 138             *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
 139           /* FIXME: how can I detect wide chars in GPC ??  */
 140           if (char_type)
 141             {
 142               *char_type = TYPE_TARGET_TYPE (type->field (2).type ());
 143
 144               if ((*char_type)->code () == TYPE_CODE_ARRAY)
 145                 *char_type = TYPE_TARGET_TYPE (*char_type);
 146             }
 147           if (arrayname)
 148             *arrayname = TYPE_FIELD_NAME (type, 2);
 149          return 3;
 150         };
 151     }
 152   return 0;
 153 }
 154
 155 static void pascal_one_char (int, struct ui_file *, int *);
 156
 157 /* Print the character C on STREAM as part of the contents of a literal
 158    string.
 159    In_quotes is reset to 0 if a char is written with #4 notation.  */
 160
 161 static void
 162 pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
 163 {
 164   if (c == '\'' || ((unsigned int) c <= 0xff && (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 void
 186 pascal_printchar (int c, struct type *type, struct ui_file *stream)
 187 {
 188   int in_quotes = 0;
 189
 190   pascal_one_char (c, stream, &in_quotes);
 191   if (in_quotes)
 192     fputs_filtered ("'", stream);
 193 }
 194
 195 \f
 196
 197 /* Table mapping opcodes into strings for printing operators
 198    and precedences of the operators.  */
 199
 200 const struct op_print pascal_op_print_tab[] =
 201 {
 202   {",", BINOP_COMMA, PREC_COMMA, 0},
 203   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 204   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 205   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 206   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 207   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 208   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 209   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 210   {">=", BINOP_GEQ, PREC_ORDER, 0},
 211   {">", BINOP_GTR, PREC_ORDER, 0},
 212   {"<", BINOP_LESS, PREC_ORDER, 0},
 213   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 214   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 215   {"+", BINOP_ADD, PREC_ADD, 0},
 216   {"-", BINOP_SUB, PREC_ADD, 0},
 217   {"*", BINOP_MUL, PREC_MUL, 0},
 218   {"/", BINOP_DIV, PREC_MUL, 0},
 219   {"div", BINOP_INTDIV, PREC_MUL, 0},
 220   {"mod", BINOP_REM, PREC_MUL, 0},
 221   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 222   {"-", UNOP_NEG, PREC_PREFIX, 0},
 223   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 224   {"^", UNOP_IND, PREC_SUFFIX, 1},
 225   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 226   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 227   {NULL, OP_NULL, PREC_PREFIX, 0}
 228 };
 229 \f
 230 enum pascal_primitive_types {
 231   pascal_primitive_type_int,
 232   pascal_primitive_type_long,
 233   pascal_primitive_type_short,
 234   pascal_primitive_type_char,
 235   pascal_primitive_type_float,
 236   pascal_primitive_type_double,
 237   pascal_primitive_type_void,
 238   pascal_primitive_type_long_long,
 239   pascal_primitive_type_signed_char,
 240   pascal_primitive_type_unsigned_char,
 241   pascal_primitive_type_unsigned_short,
 242   pascal_primitive_type_unsigned_int,
 243   pascal_primitive_type_unsigned_long,
 244   pascal_primitive_type_unsigned_long_long,
 245   pascal_primitive_type_long_double,
 246   pascal_primitive_type_complex,
 247   pascal_primitive_type_double_complex,
 248   nr_pascal_primitive_types
 249 };
 250
 251 /* Constant data representing the Pascal language.  */
 252
 253 extern const struct language_data pascal_language_data =
 254 {
 255   range_check_on,
 256   case_sensitive_on,
 257   array_row_major,
 258   macro_expansion_no,
 259   &exp_descriptor_standard,
 260   false,                        /* la_store_sym_names_in_linkage_form_p */
 261   pascal_op_print_tab,          /* expression operators for printing */
 262   &default_varobj_ops,
 263 };
 264
 265 /* Class representing the Pascal language.  */
 266
 267 class pascal_language : public language_defn
 268 {
 269 public:
 270   pascal_language ()
 271     : language_defn (language_pascal, pascal_language_data)
 272   { /* Nothing.  */ }
 273
 274   /* See language.h.  */
 275
 276   const char *name () const override
 277   { return "pascal"; }
 278
 279   /* See language.h.  */
 280
 281   const char *natural_name () const override
 282   { return "Pascal"; }
 283
 284   /* See language.h.  */
 285
 286   const std::vector<const char *> &filename_extensions () const override
 287   {
 288     static const std::vector<const char *> extensions
 289       = { ".pas", ".p", ".pp" };
 290     return extensions;
 291   }
 292
 293   /* See language.h.  */
 294   void language_arch_info (struct gdbarch *gdbarch,
 295                            struct language_arch_info *lai) const override
 296   {
 297     const struct builtin_type *builtin = builtin_type (gdbarch);
 298
 299     lai->string_char_type = builtin->builtin_char;
 300     lai->primitive_type_vector
 301       = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 302                               struct type *);
 303     lai->primitive_type_vector [pascal_primitive_type_int]
 304       = builtin->builtin_int;
 305     lai->primitive_type_vector [pascal_primitive_type_long]
 306       = builtin->builtin_long;
 307     lai->primitive_type_vector [pascal_primitive_type_short]
 308       = builtin->builtin_short;
 309     lai->primitive_type_vector [pascal_primitive_type_char]
 310       = builtin->builtin_char;
 311     lai->primitive_type_vector [pascal_primitive_type_float]
 312       = builtin->builtin_float;
 313     lai->primitive_type_vector [pascal_primitive_type_double]
 314       = builtin->builtin_double;
 315     lai->primitive_type_vector [pascal_primitive_type_void]
 316       = builtin->builtin_void;
 317     lai->primitive_type_vector [pascal_primitive_type_long_long]
 318       = builtin->builtin_long_long;
 319     lai->primitive_type_vector [pascal_primitive_type_signed_char]
 320       = builtin->builtin_signed_char;
 321     lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 322       = builtin->builtin_unsigned_char;
 323     lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 324       = builtin->builtin_unsigned_short;
 325     lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 326       = builtin->builtin_unsigned_int;
 327     lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 328       = builtin->builtin_unsigned_long;
 329     lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 330       = builtin->builtin_unsigned_long_long;
 331     lai->primitive_type_vector [pascal_primitive_type_long_double]
 332       = builtin->builtin_long_double;
 333     lai->primitive_type_vector [pascal_primitive_type_complex]
 334       = builtin->builtin_complex;
 335     lai->primitive_type_vector [pascal_primitive_type_double_complex]
 336       = builtin->builtin_double_complex;
 337
 338     lai->bool_type_symbol = "boolean";
 339     lai->bool_type_default = builtin->builtin_bool;
 340   }
 341
 342   /* See language.h.  */
 343
 344   void print_type (struct type *type, const char *varstring,
 345                    struct ui_file *stream, int show, int level,
 346                    const struct type_print_options *flags) const override
 347   {
 348     pascal_print_type (type, varstring, stream, show, level, flags);
 349   }
 350
 351   /* See language.h.  */
 352
 353   void value_print (struct value *val, struct ui_file *stream,
 354                     const struct value_print_options *options) const override
 355   {
 356     return pascal_value_print (val, stream, options);
 357   }
 358
 359   /* See language.h.  */
 360
 361   void value_print_inner
 362         (struct value *val, struct ui_file *stream, int recurse,
 363          const struct value_print_options *options) const override
 364   {
 365     return pascal_value_print_inner (val, stream, recurse, options);
 366   }
 367
 368   /* See language.h.  */
 369
 370   int parser (struct parser_state *ps) const override
 371   {
 372     return pascal_parse (ps);
 373   }
 374
 375   /* See language.h.  */
 376
 377   void emitchar (int ch, struct type *chtype,
 378                  struct ui_file *stream, int quoter) const override
 379   {
 380     int in_quotes = 0;
 381
 382     pascal_one_char (ch, stream, &in_quotes);
 383     if (in_quotes)
 384       fputs_filtered ("'", stream);
 385   }
 386
 387   /* See language.h.  */
 388
 389   void printchar (int ch, struct type *chtype,
 390                   struct ui_file *stream) const override
 391   {
 392     pascal_printchar (ch, chtype, stream);
 393   }
 394
 395   /* See language.h.  */
 396
 397   void printstr (struct ui_file *stream, struct type *elttype,
 398                  const gdb_byte *string, unsigned int length,
 399                  const char *encoding, int force_ellipses,
 400                  const struct value_print_options *options) const override
 401   {
 402     enum bfd_endian byte_order = type_byte_order (elttype);
 403     unsigned int i;
 404     unsigned int things_printed = 0;
 405     int in_quotes = 0;
 406     int need_comma = 0;
 407     int width;
 408
 409     /* Preserve ELTTYPE's original type, just set its LENGTH.  */
 410     check_typedef (elttype);
 411     width = TYPE_LENGTH (elttype);
 412
 413     /* If the string was not truncated due to `set print elements', and
 414        the last byte of it is a null, we don't print that, in traditional C
 415        style.  */
 416     if ((!force_ellipses) && length > 0
 417         && extract_unsigned_integer (string + (length - 1) * width, width,
 418                                      byte_order) == 0)
 419       length--;
 420
 421     if (length == 0)
 422       {
 423         fputs_filtered ("''", stream);
 424         return;
 425       }
 426
 427     for (i = 0; i < length && things_printed < options->print_max; ++i)
 428       {
 429         /* Position of the character we are examining
 430            to see whether it is repeated.  */
 431         unsigned int rep1;
 432         /* Number of repetitions we have detected so far.  */
 433         unsigned int reps;
 434         unsigned long int current_char;
 435
 436         QUIT;
 437
 438         if (need_comma)
 439           {
 440             fputs_filtered (", ", stream);
 441             need_comma = 0;
 442           }
 443
 444         current_char = extract_unsigned_integer (string + i * width, width,
 445                                                  byte_order);
 446
 447         rep1 = i + 1;
 448         reps = 1;
 449         while (rep1 < length
 450                && extract_unsigned_integer (string + rep1 * width, width,
 451                                             byte_order) == current_char)
 452           {
 453             ++rep1;
 454             ++reps;
 455           }
 456
 457         if (reps > options->repeat_count_threshold)
 458           {
 459             if (in_quotes)
 460               {
 461                 fputs_filtered ("', ", stream);
 462                 in_quotes = 0;
 463               }
 464             pascal_printchar (current_char, elttype, stream);
 465             fprintf_filtered (stream, " %p[<repeats %u times>%p]",
 466                               metadata_style.style ().ptr (),
 467                               reps, nullptr);
 468             i = rep1 - 1;
 469             things_printed += options->repeat_count_threshold;
 470             need_comma = 1;
 471           }
 472         else
 473           {
 474             if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 475               {
 476                 fputs_filtered ("'", stream);
 477                 in_quotes = 1;
 478               }
 479             pascal_one_char (current_char, stream, &in_quotes);
 480             ++things_printed;
 481           }
 482       }
 483
 484     /* Terminate the quotes if necessary.  */
 485     if (in_quotes)
 486       fputs_filtered ("'", stream);
 487
 488     if (force_ellipses || i < length)
 489       fputs_filtered ("...", stream);
 490   }
 491
 492   /* See language.h.  */
 493
 494   void print_typedef (struct type *type, struct symbol *new_symbol,
 495                       struct ui_file *stream) const override
 496   {
 497     pascal_print_typedef (type, new_symbol, stream);
 498   }
 499
 500   /* See language.h.  */
 501
 502   bool is_string_type_p (struct type *type) const override
 503   {
 504     return is_pascal_string_type (type, nullptr, nullptr, nullptr,
 505                                   nullptr, nullptr) > 0;
 506   }
 507
 508   /* See language.h.  */
 509
 510   const char *name_of_this () const override
 511   { return "this"; }
 512 };
 513
 514 /* Single instance of the Pascal language class.  */
 515
 516 static pascal_language pascal_language_defn;