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