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   array_row_major,
 256   macro_expansion_no,
 257   &exp_descriptor_standard,
 258   pascal_op_print_tab,          /* expression operators for printing */
 259   &default_varobj_ops,
 260 };
 261
 262 /* Class representing the Pascal language.  */
 263
 264 class pascal_language : public language_defn
 265 {
 266 public:
 267   pascal_language ()
 268     : language_defn (language_pascal, pascal_language_data)
 269   { /* Nothing.  */ }
 270
 271   /* See language.h.  */
 272
 273   const char *name () const override
 274   { return "pascal"; }
 275
 276   /* See language.h.  */
 277
 278   const char *natural_name () const override
 279   { return "Pascal"; }
 280
 281   /* See language.h.  */
 282
 283   const std::vector<const char *> &filename_extensions () const override
 284   {
 285     static const std::vector<const char *> extensions
 286       = { ".pas", ".p", ".pp" };
 287     return extensions;
 288   }
 289
 290   /* See language.h.  */
 291   void language_arch_info (struct gdbarch *gdbarch,
 292                            struct language_arch_info *lai) const override
 293   {
 294     const struct builtin_type *builtin = builtin_type (gdbarch);
 295
 296     lai->string_char_type = builtin->builtin_char;
 297     lai->primitive_type_vector
 298       = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 299                               struct type *);
 300     lai->primitive_type_vector [pascal_primitive_type_int]
 301       = builtin->builtin_int;
 302     lai->primitive_type_vector [pascal_primitive_type_long]
 303       = builtin->builtin_long;
 304     lai->primitive_type_vector [pascal_primitive_type_short]
 305       = builtin->builtin_short;
 306     lai->primitive_type_vector [pascal_primitive_type_char]
 307       = builtin->builtin_char;
 308     lai->primitive_type_vector [pascal_primitive_type_float]
 309       = builtin->builtin_float;
 310     lai->primitive_type_vector [pascal_primitive_type_double]
 311       = builtin->builtin_double;
 312     lai->primitive_type_vector [pascal_primitive_type_void]
 313       = builtin->builtin_void;
 314     lai->primitive_type_vector [pascal_primitive_type_long_long]
 315       = builtin->builtin_long_long;
 316     lai->primitive_type_vector [pascal_primitive_type_signed_char]
 317       = builtin->builtin_signed_char;
 318     lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 319       = builtin->builtin_unsigned_char;
 320     lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 321       = builtin->builtin_unsigned_short;
 322     lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 323       = builtin->builtin_unsigned_int;
 324     lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 325       = builtin->builtin_unsigned_long;
 326     lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 327       = builtin->builtin_unsigned_long_long;
 328     lai->primitive_type_vector [pascal_primitive_type_long_double]
 329       = builtin->builtin_long_double;
 330     lai->primitive_type_vector [pascal_primitive_type_complex]
 331       = builtin->builtin_complex;
 332     lai->primitive_type_vector [pascal_primitive_type_double_complex]
 333       = builtin->builtin_double_complex;
 334
 335     lai->bool_type_symbol = "boolean";
 336     lai->bool_type_default = builtin->builtin_bool;
 337   }
 338
 339   /* See language.h.  */
 340
 341   void print_type (struct type *type, const char *varstring,
 342                    struct ui_file *stream, int show, int level,
 343                    const struct type_print_options *flags) const override
 344   {
 345     pascal_print_type (type, varstring, stream, show, level, flags);
 346   }
 347
 348   /* See language.h.  */
 349
 350   void value_print (struct value *val, struct ui_file *stream,
 351                     const struct value_print_options *options) const override
 352   {
 353     return pascal_value_print (val, stream, options);
 354   }
 355
 356   /* See language.h.  */
 357
 358   void value_print_inner
 359         (struct value *val, struct ui_file *stream, int recurse,
 360          const struct value_print_options *options) const override
 361   {
 362     return pascal_value_print_inner (val, stream, recurse, options);
 363   }
 364
 365   /* See language.h.  */
 366
 367   int parser (struct parser_state *ps) const override
 368   {
 369     return pascal_parse (ps);
 370   }
 371
 372   /* See language.h.  */
 373
 374   void emitchar (int ch, struct type *chtype,
 375                  struct ui_file *stream, int quoter) const override
 376   {
 377     int in_quotes = 0;
 378
 379     pascal_one_char (ch, stream, &in_quotes);
 380     if (in_quotes)
 381       fputs_filtered ("'", stream);
 382   }
 383
 384   /* See language.h.  */
 385
 386   void printchar (int ch, struct type *chtype,
 387                   struct ui_file *stream) const override
 388   {
 389     pascal_printchar (ch, chtype, stream);
 390   }
 391
 392   /* See language.h.  */
 393
 394   void printstr (struct ui_file *stream, struct type *elttype,
 395                  const gdb_byte *string, unsigned int length,
 396                  const char *encoding, int force_ellipses,
 397                  const struct value_print_options *options) const override
 398   {
 399     enum bfd_endian byte_order = type_byte_order (elttype);
 400     unsigned int i;
 401     unsigned int things_printed = 0;
 402     int in_quotes = 0;
 403     int need_comma = 0;
 404     int width;
 405
 406     /* Preserve ELTTYPE's original type, just set its LENGTH.  */
 407     check_typedef (elttype);
 408     width = TYPE_LENGTH (elttype);
 409
 410     /* If the string was not truncated due to `set print elements', and
 411        the last byte of it is a null, we don't print that, in traditional C
 412        style.  */
 413     if ((!force_ellipses) && length > 0
 414         && extract_unsigned_integer (string + (length - 1) * width, width,
 415                                      byte_order) == 0)
 416       length--;
 417
 418     if (length == 0)
 419       {
 420         fputs_filtered ("''", stream);
 421         return;
 422       }
 423
 424     for (i = 0; i < length && things_printed < options->print_max; ++i)
 425       {
 426         /* Position of the character we are examining
 427            to see whether it is repeated.  */
 428         unsigned int rep1;
 429         /* Number of repetitions we have detected so far.  */
 430         unsigned int reps;
 431         unsigned long int current_char;
 432
 433         QUIT;
 434
 435         if (need_comma)
 436           {
 437             fputs_filtered (", ", stream);
 438             need_comma = 0;
 439           }
 440
 441         current_char = extract_unsigned_integer (string + i * width, width,
 442                                                  byte_order);
 443
 444         rep1 = i + 1;
 445         reps = 1;
 446         while (rep1 < length
 447                && extract_unsigned_integer (string + rep1 * width, width,
 448                                             byte_order) == current_char)
 449           {
 450             ++rep1;
 451             ++reps;
 452           }
 453
 454         if (reps > options->repeat_count_threshold)
 455           {
 456             if (in_quotes)
 457               {
 458                 fputs_filtered ("', ", stream);
 459                 in_quotes = 0;
 460               }
 461             pascal_printchar (current_char, elttype, stream);
 462             fprintf_filtered (stream, " %p[<repeats %u times>%p]",
 463                               metadata_style.style ().ptr (),
 464                               reps, nullptr);
 465             i = rep1 - 1;
 466             things_printed += options->repeat_count_threshold;
 467             need_comma = 1;
 468           }
 469         else
 470           {
 471             if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 472               {
 473                 fputs_filtered ("'", stream);
 474                 in_quotes = 1;
 475               }
 476             pascal_one_char (current_char, stream, &in_quotes);
 477             ++things_printed;
 478           }
 479       }
 480
 481     /* Terminate the quotes if necessary.  */
 482     if (in_quotes)
 483       fputs_filtered ("'", stream);
 484
 485     if (force_ellipses || i < length)
 486       fputs_filtered ("...", stream);
 487   }
 488
 489   /* See language.h.  */
 490
 491   void print_typedef (struct type *type, struct symbol *new_symbol,
 492                       struct ui_file *stream) const override
 493   {
 494     pascal_print_typedef (type, new_symbol, stream);
 495   }
 496
 497   /* See language.h.  */
 498
 499   bool is_string_type_p (struct type *type) const override
 500   {
 501     return is_pascal_string_type (type, nullptr, nullptr, nullptr,
 502                                   nullptr, nullptr) > 0;
 503   }
 504
 505   /* See language.h.  */
 506
 507   const char *name_of_this () const override
 508   { return "this"; }
 509
 510   /* See language.h.  */
 511
 512   bool range_checking_on_by_default () const override
 513   { return true; }
 514 };
 515
 516 /* Single instance of the Pascal language class.  */
 517
 518 static pascal_language pascal_language_defn;