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 static const char * const p_extensions[] =
 252 {
 253   ".pas", ".p", ".pp", NULL
 254 };
 255
 256 /* Constant data representing the Pascal language.  */
 257
 258 extern const struct language_data pascal_language_data =
 259 {
 260   language_pascal,
 261   range_check_on,
 262   case_sensitive_on,
 263   array_row_major,
 264   macro_expansion_no,
 265   p_extensions,
 266   &exp_descriptor_standard,
 267   false,                        /* la_store_sym_names_in_linkage_form_p */
 268   pascal_op_print_tab,          /* expression operators for printing */
 269   1,                            /* c-style arrays */
 270   0,                            /* String lower bound */
 271   &default_varobj_ops,
 272 };
 273
 274 /* Class representing the Pascal language.  */
 275
 276 class pascal_language : public language_defn
 277 {
 278 public:
 279   pascal_language ()
 280     : language_defn (language_pascal, pascal_language_data)
 281   { /* Nothing.  */ }
 282
 283   /* See language.h.  */
 284
 285   const char *name () const override
 286   { return "pascal"; }
 287
 288   /* See language.h.  */
 289
 290   const char *natural_name () const override
 291   { return "Pascal"; }
 292
 293
 294   /* See language.h.  */
 295   void language_arch_info (struct gdbarch *gdbarch,
 296                            struct language_arch_info *lai) const override
 297   {
 298     const struct builtin_type *builtin = builtin_type (gdbarch);
 299
 300     lai->string_char_type = builtin->builtin_char;
 301     lai->primitive_type_vector
 302       = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 303                               struct type *);
 304     lai->primitive_type_vector [pascal_primitive_type_int]
 305       = builtin->builtin_int;
 306     lai->primitive_type_vector [pascal_primitive_type_long]
 307       = builtin->builtin_long;
 308     lai->primitive_type_vector [pascal_primitive_type_short]
 309       = builtin->builtin_short;
 310     lai->primitive_type_vector [pascal_primitive_type_char]
 311       = builtin->builtin_char;
 312     lai->primitive_type_vector [pascal_primitive_type_float]
 313       = builtin->builtin_float;
 314     lai->primitive_type_vector [pascal_primitive_type_double]
 315       = builtin->builtin_double;
 316     lai->primitive_type_vector [pascal_primitive_type_void]
 317       = builtin->builtin_void;
 318     lai->primitive_type_vector [pascal_primitive_type_long_long]
 319       = builtin->builtin_long_long;
 320     lai->primitive_type_vector [pascal_primitive_type_signed_char]
 321       = builtin->builtin_signed_char;
 322     lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 323       = builtin->builtin_unsigned_char;
 324     lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 325       = builtin->builtin_unsigned_short;
 326     lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 327       = builtin->builtin_unsigned_int;
 328     lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 329       = builtin->builtin_unsigned_long;
 330     lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 331       = builtin->builtin_unsigned_long_long;
 332     lai->primitive_type_vector [pascal_primitive_type_long_double]
 333       = builtin->builtin_long_double;
 334     lai->primitive_type_vector [pascal_primitive_type_complex]
 335       = builtin->builtin_complex;
 336     lai->primitive_type_vector [pascal_primitive_type_double_complex]
 337       = builtin->builtin_double_complex;
 338
 339     lai->bool_type_symbol = "boolean";
 340     lai->bool_type_default = builtin->builtin_bool;
 341   }
 342
 343   /* See language.h.  */
 344
 345   void print_type (struct type *type, const char *varstring,
 346                    struct ui_file *stream, int show, int level,
 347                    const struct type_print_options *flags) const override
 348   {
 349     pascal_print_type (type, varstring, stream, show, level, flags);
 350   }
 351
 352   /* See language.h.  */
 353
 354   void value_print (struct value *val, struct ui_file *stream,
 355                     const struct value_print_options *options) const override
 356   {
 357     return pascal_value_print (val, stream, options);
 358   }
 359
 360   /* See language.h.  */
 361
 362   void value_print_inner
 363         (struct value *val, struct ui_file *stream, int recurse,
 364          const struct value_print_options *options) const override
 365   {
 366     return pascal_value_print_inner (val, stream, recurse, options);
 367   }
 368
 369   /* See language.h.  */
 370
 371   int parser (struct parser_state *ps) const override
 372   {
 373     return pascal_parse (ps);
 374   }
 375
 376   /* See language.h.  */
 377
 378   void emitchar (int ch, struct type *chtype,
 379                  struct ui_file *stream, int quoter) const override
 380   {
 381     int in_quotes = 0;
 382
 383     pascal_one_char (ch, stream, &in_quotes);
 384     if (in_quotes)
 385       fputs_filtered ("'", stream);
 386   }
 387
 388   /* See language.h.  */
 389
 390   void printchar (int ch, struct type *chtype,
 391                   struct ui_file *stream) const override
 392   {
 393     pascal_printchar (ch, chtype, stream);
 394   }
 395
 396   /* See language.h.  */
 397
 398   void printstr (struct ui_file *stream, struct type *elttype,
 399                  const gdb_byte *string, unsigned int length,
 400                  const char *encoding, int force_ellipses,
 401                  const struct value_print_options *options) const override
 402   {
 403     enum bfd_endian byte_order = type_byte_order (elttype);
 404     unsigned int i;
 405     unsigned int things_printed = 0;
 406     int in_quotes = 0;
 407     int need_comma = 0;
 408     int width;
 409
 410     /* Preserve ELTTYPE's original type, just set its LENGTH.  */
 411     check_typedef (elttype);
 412     width = TYPE_LENGTH (elttype);
 413
 414     /* If the string was not truncated due to `set print elements', and
 415        the last byte of it is a null, we don't print that, in traditional C
 416        style.  */
 417     if ((!force_ellipses) && length > 0
 418         && extract_unsigned_integer (string + (length - 1) * width, width,
 419                                      byte_order) == 0)
 420       length--;
 421
 422     if (length == 0)
 423       {
 424         fputs_filtered ("''", stream);
 425         return;
 426       }
 427
 428     for (i = 0; i < length && things_printed < options->print_max; ++i)
 429       {
 430         /* Position of the character we are examining
 431            to see whether it is repeated.  */
 432         unsigned int rep1;
 433         /* Number of repetitions we have detected so far.  */
 434         unsigned int reps;
 435         unsigned long int current_char;
 436
 437         QUIT;
 438
 439         if (need_comma)
 440           {
 441             fputs_filtered (", ", stream);
 442             need_comma = 0;
 443           }
 444
 445         current_char = extract_unsigned_integer (string + i * width, width,
 446                                                  byte_order);
 447
 448         rep1 = i + 1;
 449         reps = 1;
 450         while (rep1 < length
 451                && extract_unsigned_integer (string + rep1 * width, width,
 452                                             byte_order) == current_char)
 453           {
 454             ++rep1;
 455             ++reps;
 456           }
 457
 458         if (reps > options->repeat_count_threshold)
 459           {
 460             if (in_quotes)
 461               {
 462                 fputs_filtered ("', ", stream);
 463                 in_quotes = 0;
 464               }
 465             pascal_printchar (current_char, elttype, stream);
 466             fprintf_filtered (stream, " %p[<repeats %u times>%p]",
 467                               metadata_style.style ().ptr (),
 468                               reps, nullptr);
 469             i = rep1 - 1;
 470             things_printed += options->repeat_count_threshold;
 471             need_comma = 1;
 472           }
 473         else
 474           {
 475             if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 476               {
 477                 fputs_filtered ("'", stream);
 478                 in_quotes = 1;
 479               }
 480             pascal_one_char (current_char, stream, &in_quotes);
 481             ++things_printed;
 482           }
 483       }
 484
 485     /* Terminate the quotes if necessary.  */
 486     if (in_quotes)
 487       fputs_filtered ("'", stream);
 488
 489     if (force_ellipses || i < length)
 490       fputs_filtered ("...", stream);
 491   }
 492
 493   /* See language.h.  */
 494
 495   void print_typedef (struct type *type, struct symbol *new_symbol,
 496                       struct ui_file *stream) const override
 497   {
 498     pascal_print_typedef (type, new_symbol, stream);
 499   }
 500
 501   /* See language.h.  */
 502
 503   bool is_string_type_p (struct type *type) const override
 504   {
 505     return is_pascal_string_type (type, nullptr, nullptr, nullptr,
 506                                   nullptr, nullptr) > 0;
 507   }
 508
 509   /* See language.h.  */
 510
 511   const char *name_of_this () const override
 512   { return "this"; }
 513 };
 514
 515 /* Single instance of the Pascal language class.  */
 516
 517 static pascal_language pascal_language_defn;