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 /* Class representing the Pascal language.  */
 252
 253 class pascal_language : public language_defn
 254 {
 255 public:
 256   pascal_language ()
 257     : language_defn (language_pascal)
 258   { /* Nothing.  */ }
 259
 260   /* See language.h.  */
 261
 262   const char *name () const override
 263   { return "pascal"; }
 264
 265   /* See language.h.  */
 266
 267   const char *natural_name () const override
 268   { return "Pascal"; }
 269
 270   /* See language.h.  */
 271
 272   const std::vector<const char *> &filename_extensions () const override
 273   {
 274     static const std::vector<const char *> extensions
 275       = { ".pas", ".p", ".pp" };
 276     return extensions;
 277   }
 278
 279   /* See language.h.  */
 280   void language_arch_info (struct gdbarch *gdbarch,
 281                            struct language_arch_info *lai) const override
 282   {
 283     const struct builtin_type *builtin = builtin_type (gdbarch);
 284
 285     lai->string_char_type = builtin->builtin_char;
 286     lai->primitive_type_vector
 287       = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 288                               struct type *);
 289     lai->primitive_type_vector [pascal_primitive_type_int]
 290       = builtin->builtin_int;
 291     lai->primitive_type_vector [pascal_primitive_type_long]
 292       = builtin->builtin_long;
 293     lai->primitive_type_vector [pascal_primitive_type_short]
 294       = builtin->builtin_short;
 295     lai->primitive_type_vector [pascal_primitive_type_char]
 296       = builtin->builtin_char;
 297     lai->primitive_type_vector [pascal_primitive_type_float]
 298       = builtin->builtin_float;
 299     lai->primitive_type_vector [pascal_primitive_type_double]
 300       = builtin->builtin_double;
 301     lai->primitive_type_vector [pascal_primitive_type_void]
 302       = builtin->builtin_void;
 303     lai->primitive_type_vector [pascal_primitive_type_long_long]
 304       = builtin->builtin_long_long;
 305     lai->primitive_type_vector [pascal_primitive_type_signed_char]
 306       = builtin->builtin_signed_char;
 307     lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 308       = builtin->builtin_unsigned_char;
 309     lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 310       = builtin->builtin_unsigned_short;
 311     lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 312       = builtin->builtin_unsigned_int;
 313     lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 314       = builtin->builtin_unsigned_long;
 315     lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 316       = builtin->builtin_unsigned_long_long;
 317     lai->primitive_type_vector [pascal_primitive_type_long_double]
 318       = builtin->builtin_long_double;
 319     lai->primitive_type_vector [pascal_primitive_type_complex]
 320       = builtin->builtin_complex;
 321     lai->primitive_type_vector [pascal_primitive_type_double_complex]
 322       = builtin->builtin_double_complex;
 323
 324     lai->bool_type_symbol = "boolean";
 325     lai->bool_type_default = builtin->builtin_bool;
 326   }
 327
 328   /* See language.h.  */
 329
 330   void print_type (struct type *type, const char *varstring,
 331                    struct ui_file *stream, int show, int level,
 332                    const struct type_print_options *flags) const override
 333   {
 334     pascal_print_type (type, varstring, stream, show, level, flags);
 335   }
 336
 337   /* See language.h.  */
 338
 339   void value_print (struct value *val, struct ui_file *stream,
 340                     const struct value_print_options *options) const override
 341   {
 342     return pascal_value_print (val, stream, options);
 343   }
 344
 345   /* See language.h.  */
 346
 347   void value_print_inner
 348         (struct value *val, struct ui_file *stream, int recurse,
 349          const struct value_print_options *options) const override
 350   {
 351     return pascal_value_print_inner (val, stream, recurse, options);
 352   }
 353
 354   /* See language.h.  */
 355
 356   int parser (struct parser_state *ps) const override
 357   {
 358     return pascal_parse (ps);
 359   }
 360
 361   /* See language.h.  */
 362
 363   void emitchar (int ch, struct type *chtype,
 364                  struct ui_file *stream, int quoter) const override
 365   {
 366     int in_quotes = 0;
 367
 368     pascal_one_char (ch, stream, &in_quotes);
 369     if (in_quotes)
 370       fputs_filtered ("'", stream);
 371   }
 372
 373   /* See language.h.  */
 374
 375   void printchar (int ch, struct type *chtype,
 376                   struct ui_file *stream) const override
 377   {
 378     pascal_printchar (ch, chtype, stream);
 379   }
 380
 381   /* See language.h.  */
 382
 383   void printstr (struct ui_file *stream, struct type *elttype,
 384                  const gdb_byte *string, unsigned int length,
 385                  const char *encoding, int force_ellipses,
 386                  const struct value_print_options *options) const override
 387   {
 388     enum bfd_endian byte_order = type_byte_order (elttype);
 389     unsigned int i;
 390     unsigned int things_printed = 0;
 391     int in_quotes = 0;
 392     int need_comma = 0;
 393     int width;
 394
 395     /* Preserve ELTTYPE's original type, just set its LENGTH.  */
 396     check_typedef (elttype);
 397     width = TYPE_LENGTH (elttype);
 398
 399     /* If the string was not truncated due to `set print elements', and
 400        the last byte of it is a null, we don't print that, in traditional C
 401        style.  */
 402     if ((!force_ellipses) && length > 0
 403         && extract_unsigned_integer (string + (length - 1) * width, width,
 404                                      byte_order) == 0)
 405       length--;
 406
 407     if (length == 0)
 408       {
 409         fputs_filtered ("''", stream);
 410         return;
 411       }
 412
 413     for (i = 0; i < length && things_printed < options->print_max; ++i)
 414       {
 415         /* Position of the character we are examining
 416            to see whether it is repeated.  */
 417         unsigned int rep1;
 418         /* Number of repetitions we have detected so far.  */
 419         unsigned int reps;
 420         unsigned long int current_char;
 421
 422         QUIT;
 423
 424         if (need_comma)
 425           {
 426             fputs_filtered (", ", stream);
 427             need_comma = 0;
 428           }
 429
 430         current_char = extract_unsigned_integer (string + i * width, width,
 431                                                  byte_order);
 432
 433         rep1 = i + 1;
 434         reps = 1;
 435         while (rep1 < length
 436                && extract_unsigned_integer (string + rep1 * width, width,
 437                                             byte_order) == current_char)
 438           {
 439             ++rep1;
 440             ++reps;
 441           }
 442
 443         if (reps > options->repeat_count_threshold)
 444           {
 445             if (in_quotes)
 446               {
 447                 fputs_filtered ("', ", stream);
 448                 in_quotes = 0;
 449               }
 450             pascal_printchar (current_char, elttype, stream);
 451             fprintf_filtered (stream, " %p[<repeats %u times>%p]",
 452                               metadata_style.style ().ptr (),
 453                               reps, nullptr);
 454             i = rep1 - 1;
 455             things_printed += options->repeat_count_threshold;
 456             need_comma = 1;
 457           }
 458         else
 459           {
 460             if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 461               {
 462                 fputs_filtered ("'", stream);
 463                 in_quotes = 1;
 464               }
 465             pascal_one_char (current_char, stream, &in_quotes);
 466             ++things_printed;
 467           }
 468       }
 469
 470     /* Terminate the quotes if necessary.  */
 471     if (in_quotes)
 472       fputs_filtered ("'", stream);
 473
 474     if (force_ellipses || i < length)
 475       fputs_filtered ("...", stream);
 476   }
 477
 478   /* See language.h.  */
 479
 480   void print_typedef (struct type *type, struct symbol *new_symbol,
 481                       struct ui_file *stream) const override
 482   {
 483     pascal_print_typedef (type, new_symbol, stream);
 484   }
 485
 486   /* See language.h.  */
 487
 488   bool is_string_type_p (struct type *type) const override
 489   {
 490     return is_pascal_string_type (type, nullptr, nullptr, nullptr,
 491                                   nullptr, nullptr) > 0;
 492   }
 493
 494   /* See language.h.  */
 495
 496   const char *name_of_this () const override
 497   { return "this"; }
 498
 499   /* See language.h.  */
 500
 501   bool range_checking_on_by_default () const override
 502   { return true; }
 503
 504   /* See language.h.  */
 505
 506   const struct op_print *opcode_print_table () const override
 507   { return pascal_op_print_tab; }
 508 };
 509
 510 /* Single instance of the Pascal language class.  */
 511
 512 static pascal_language pascal_language_defn;