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