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   1,                            /* c-style arrays */
 263   0,                            /* String lower bound */
 264   &default_varobj_ops,
 265 };
 266
 267 /* Class representing the Pascal language.  */
 268
 269 class pascal_language : public language_defn
 270 {
 271 public:
 272   pascal_language ()
 273     : language_defn (language_pascal, pascal_language_data)
 274   { /* Nothing.  */ }
 275
 276   /* See language.h.  */
 277
 278   const char *name () const override
 279   { return "pascal"; }
 280
 281   /* See language.h.  */
 282
 283   const char *natural_name () const override
 284   { return "Pascal"; }
 285
 286   /* See language.h.  */
 287
 288   const std::vector<const char *> &filename_extensions () const override
 289   {
 290     static const std::vector<const char *> extensions
 291       = { ".pas", ".p", ".pp" };
 292     return extensions;
 293   }
 294
 295   /* See language.h.  */
 296   void language_arch_info (struct gdbarch *gdbarch,
 297                            struct language_arch_info *lai) const override
 298   {
 299     const struct builtin_type *builtin = builtin_type (gdbarch);
 300
 301     lai->string_char_type = builtin->builtin_char;
 302     lai->primitive_type_vector
 303       = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 304                               struct type *);
 305     lai->primitive_type_vector [pascal_primitive_type_int]
 306       = builtin->builtin_int;
 307     lai->primitive_type_vector [pascal_primitive_type_long]
 308       = builtin->builtin_long;
 309     lai->primitive_type_vector [pascal_primitive_type_short]
 310       = builtin->builtin_short;
 311     lai->primitive_type_vector [pascal_primitive_type_char]
 312       = builtin->builtin_char;
 313     lai->primitive_type_vector [pascal_primitive_type_float]
 314       = builtin->builtin_float;
 315     lai->primitive_type_vector [pascal_primitive_type_double]
 316       = builtin->builtin_double;
 317     lai->primitive_type_vector [pascal_primitive_type_void]
 318       = builtin->builtin_void;
 319     lai->primitive_type_vector [pascal_primitive_type_long_long]
 320       = builtin->builtin_long_long;
 321     lai->primitive_type_vector [pascal_primitive_type_signed_char]
 322       = builtin->builtin_signed_char;
 323     lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 324       = builtin->builtin_unsigned_char;
 325     lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 326       = builtin->builtin_unsigned_short;
 327     lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 328       = builtin->builtin_unsigned_int;
 329     lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 330       = builtin->builtin_unsigned_long;
 331     lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 332       = builtin->builtin_unsigned_long_long;
 333     lai->primitive_type_vector [pascal_primitive_type_long_double]
 334       = builtin->builtin_long_double;
 335     lai->primitive_type_vector [pascal_primitive_type_complex]
 336       = builtin->builtin_complex;
 337     lai->primitive_type_vector [pascal_primitive_type_double_complex]
 338       = builtin->builtin_double_complex;
 339
 340     lai->bool_type_symbol = "boolean";
 341     lai->bool_type_default = builtin->builtin_bool;
 342   }
 343
 344   /* See language.h.  */
 345
 346   void print_type (struct type *type, const char *varstring,
 347                    struct ui_file *stream, int show, int level,
 348                    const struct type_print_options *flags) const override
 349   {
 350     pascal_print_type (type, varstring, stream, show, level, flags);
 351   }
 352
 353   /* See language.h.  */
 354
 355   void value_print (struct value *val, struct ui_file *stream,
 356                     const struct value_print_options *options) const override
 357   {
 358     return pascal_value_print (val, stream, options);
 359   }
 360
 361   /* See language.h.  */
 362
 363   void value_print_inner
 364         (struct value *val, struct ui_file *stream, int recurse,
 365          const struct value_print_options *options) const override
 366   {
 367     return pascal_value_print_inner (val, stream, recurse, options);
 368   }
 369
 370   /* See language.h.  */
 371
 372   int parser (struct parser_state *ps) const override
 373   {
 374     return pascal_parse (ps);
 375   }
 376
 377   /* See language.h.  */
 378
 379   void emitchar (int ch, struct type *chtype,
 380                  struct ui_file *stream, int quoter) const override
 381   {
 382     int in_quotes = 0;
 383
 384     pascal_one_char (ch, stream, &in_quotes);
 385     if (in_quotes)
 386       fputs_filtered ("'", stream);
 387   }
 388
 389   /* See language.h.  */
 390
 391   void printchar (int ch, struct type *chtype,
 392                   struct ui_file *stream) const override
 393   {
 394     pascal_printchar (ch, chtype, stream);
 395   }
 396
 397   /* See language.h.  */
 398
 399   void printstr (struct ui_file *stream, struct type *elttype,
 400                  const gdb_byte *string, unsigned int length,
 401                  const char *encoding, int force_ellipses,
 402                  const struct value_print_options *options) const override
 403   {
 404     enum bfd_endian byte_order = type_byte_order (elttype);
 405     unsigned int i;
 406     unsigned int things_printed = 0;
 407     int in_quotes = 0;
 408     int need_comma = 0;
 409     int width;
 410
 411     /* Preserve ELTTYPE's original type, just set its LENGTH.  */
 412     check_typedef (elttype);
 413     width = TYPE_LENGTH (elttype);
 414
 415     /* If the string was not truncated due to `set print elements', and
 416        the last byte of it is a null, we don't print that, in traditional C
 417        style.  */
 418     if ((!force_ellipses) && length > 0
 419         && extract_unsigned_integer (string + (length - 1) * width, width,
 420                                      byte_order) == 0)
 421       length--;
 422
 423     if (length == 0)
 424       {
 425         fputs_filtered ("''", stream);
 426         return;
 427       }
 428
 429     for (i = 0; i < length && things_printed < options->print_max; ++i)
 430       {
 431         /* Position of the character we are examining
 432            to see whether it is repeated.  */
 433         unsigned int rep1;
 434         /* Number of repetitions we have detected so far.  */
 435         unsigned int reps;
 436         unsigned long int current_char;
 437
 438         QUIT;
 439
 440         if (need_comma)
 441           {
 442             fputs_filtered (", ", stream);
 443             need_comma = 0;
 444           }
 445
 446         current_char = extract_unsigned_integer (string + i * width, width,
 447                                                  byte_order);
 448
 449         rep1 = i + 1;
 450         reps = 1;
 451         while (rep1 < length
 452                && extract_unsigned_integer (string + rep1 * width, width,
 453                                             byte_order) == current_char)
 454           {
 455             ++rep1;
 456             ++reps;
 457           }
 458
 459         if (reps > options->repeat_count_threshold)
 460           {
 461             if (in_quotes)
 462               {
 463                 fputs_filtered ("', ", stream);
 464                 in_quotes = 0;
 465               }
 466             pascal_printchar (current_char, elttype, stream);
 467             fprintf_filtered (stream, " %p[<repeats %u times>%p]",
 468                               metadata_style.style ().ptr (),
 469                               reps, nullptr);
 470             i = rep1 - 1;
 471             things_printed += options->repeat_count_threshold;
 472             need_comma = 1;
 473           }
 474         else
 475           {
 476             if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 477               {
 478                 fputs_filtered ("'", stream);
 479                 in_quotes = 1;
 480               }
 481             pascal_one_char (current_char, stream, &in_quotes);
 482             ++things_printed;
 483           }
 484       }
 485
 486     /* Terminate the quotes if necessary.  */
 487     if (in_quotes)
 488       fputs_filtered ("'", stream);
 489
 490     if (force_ellipses || i < length)
 491       fputs_filtered ("...", stream);
 492   }
 493
 494   /* See language.h.  */
 495
 496   void print_typedef (struct type *type, struct symbol *new_symbol,
 497                       struct ui_file *stream) const override
 498   {
 499     pascal_print_typedef (type, new_symbol, stream);
 500   }
 501
 502   /* See language.h.  */
 503
 504   bool is_string_type_p (struct type *type) const override
 505   {
 506     return is_pascal_string_type (type, nullptr, nullptr, nullptr,
 507                                   nullptr, nullptr) > 0;
 508   }
 509
 510   /* See language.h.  */
 511
 512   const char *name_of_this () const override
 513   { return "this"; }
 514 };
 515
 516 /* Single instance of the Pascal language class.  */
 517
 518 static pascal_language pascal_language_defn;