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