gdb/p-lang.c

   1 /* Pascal language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2019 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
  35 /* All GPC versions until now (2007-09-27) also define a symbol called
  36    '_p_initialize'.  Check for the presence of this symbol first.  */
  37 static const char GPC_P_INITIALIZE[] = "_p_initialize";
  38
  39 /* The name of the symbol that GPC uses as the name of the main
  40    procedure (since version 20050212).  */
  41 static const char GPC_MAIN_PROGRAM_NAME_1[] = "_p__M0_main_program";
  42
  43 /* Older versions of GPC (versions older than 20050212) were using
  44    a different name for the main procedure.  */
  45 static const char GPC_MAIN_PROGRAM_NAME_2[] = "pascal_main_program";
  46
  47 /* Function returning the special symbol name used
  48    by GPC for the main procedure in the main program
  49    if it is found in minimal symbol list.
  50    This function tries to find minimal symbols generated by GPC
  51    so that it finds the even if the program was compiled
  52    without debugging information.
  53    According to information supplied by Waldeck Hebisch,
  54    this should work for all versions posterior to June 2000.  */
  55
  56 const char *
  57 pascal_main_name (void)
  58 {
  59   struct bound_minimal_symbol msym;
  60
  61   msym = lookup_minimal_symbol (GPC_P_INITIALIZE, NULL, NULL);
  62
  63   /*  If '_p_initialize' was not found, the main program is likely not
  64      written in Pascal.  */
  65   if (msym.minsym == NULL)
  66     return NULL;
  67
  68   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_1, NULL, NULL);
  69   if (msym.minsym != NULL)
  70     {
  71       return GPC_MAIN_PROGRAM_NAME_1;
  72     }
  73
  74   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_2, NULL, NULL);
  75   if (msym.minsym != NULL)
  76     {
  77       return GPC_MAIN_PROGRAM_NAME_2;
  78     }
  79
  80   /*  No known entry procedure found, the main program is probably
  81       not compiled with GPC.  */
  82   return NULL;
  83 }
  84
  85 /* Determines if type TYPE is a pascal string type.
  86    Returns a positive value if the type is a known pascal string type.
  87    This function is used by p-valprint.c code to allow better string display.
  88    If it is a pascal string type, then it also sets info needed
  89    to get the length and the data of the string
  90    length_pos, length_size and string_pos are given in bytes.
  91    char_size gives the element size in bytes.
  92    FIXME: if the position or the size of these fields
  93    are not multiple of TARGET_CHAR_BIT then the results are wrong
  94    but this does not happen for Free Pascal nor for GPC.  */
  95 int
  96 is_pascal_string_type (struct type *type,int *length_pos,
  97                        int *length_size, int *string_pos,
  98                        struct type **char_type,
  99                        const char **arrayname)
 100 {
 101   if (type != NULL && TYPE_CODE (type) == TYPE_CODE_STRUCT)
 102     {
 103       /* Old Borland type pascal strings from Free Pascal Compiler.  */
 104       /* Two fields: length and st.  */
 105       if (TYPE_NFIELDS (type) == 2
 106           && TYPE_FIELD_NAME (type, 0)
 107           && strcmp (TYPE_FIELD_NAME (type, 0), "length") == 0
 108           && TYPE_FIELD_NAME (type, 1)
 109           && strcmp (TYPE_FIELD_NAME (type, 1), "st") == 0)
 110         {
 111           if (length_pos)
 112             *length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
 113           if (length_size)
 114             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0));
 115           if (string_pos)
 116             *string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 117           if (char_type)
 118             *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 1));
 119           if (arrayname)
 120             *arrayname = TYPE_FIELD_NAME (type, 1);
 121          return 2;
 122         };
 123       /* GNU pascal strings.  */
 124       /* Three fields: Capacity, length and schema$ or _p_schema.  */
 125       if (TYPE_NFIELDS (type) == 3
 126           && TYPE_FIELD_NAME (type, 0)
 127           && strcmp (TYPE_FIELD_NAME (type, 0), "Capacity") == 0
 128           && TYPE_FIELD_NAME (type, 1)
 129           && strcmp (TYPE_FIELD_NAME (type, 1), "length") == 0)
 130         {
 131           if (length_pos)
 132             *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 133           if (length_size)
 134             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 1));
 135           if (string_pos)
 136             *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
 137           /* FIXME: how can I detect wide chars in GPC ??  */
 138           if (char_type)
 139             {
 140               *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 2));
 141
 142               if (TYPE_CODE (*char_type) == TYPE_CODE_ARRAY)
 143                 *char_type = TYPE_TARGET_TYPE (*char_type);
 144             }
 145           if (arrayname)
 146             *arrayname = TYPE_FIELD_NAME (type, 2);
 147          return 3;
 148         };
 149     }
 150   return 0;
 151 }
 152
 153 /* This is a wrapper around IS_PASCAL_STRING_TYPE that returns true if TYPE
 154    is a string.  */
 155
 156 static bool
 157 pascal_is_string_type_p (struct type *type)
 158 {
 159   return is_pascal_string_type (type, nullptr, nullptr, nullptr,
 160                                 nullptr, nullptr) > 0;
 161 }
 162
 163 static void pascal_one_char (int, struct ui_file *, int *);
 164
 165 /* Print the character C on STREAM as part of the contents of a literal
 166    string.
 167    In_quotes is reset to 0 if a char is written with #4 notation.  */
 168
 169 static void
 170 pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
 171 {
 172   if (c == '\'' || ((unsigned int) c <= 0xff && (PRINT_LITERAL_FORM (c))))
 173     {
 174       if (!(*in_quotes))
 175         fputs_filtered ("'", stream);
 176       *in_quotes = 1;
 177       if (c == '\'')
 178         {
 179           fputs_filtered ("''", stream);
 180         }
 181       else
 182         fprintf_filtered (stream, "%c", c);
 183     }
 184   else
 185     {
 186       if (*in_quotes)
 187         fputs_filtered ("'", stream);
 188       *in_quotes = 0;
 189       fprintf_filtered (stream, "#%d", (unsigned int) c);
 190     }
 191 }
 192
 193 static void pascal_emit_char (int c, struct type *type,
 194                               struct ui_file *stream, int quoter);
 195
 196 /* Print the character C on STREAM as part of the contents of a literal
 197    string whose delimiter is QUOTER.  Note that that format for printing
 198    characters and strings is language specific.  */
 199
 200 static void
 201 pascal_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
 202 {
 203   int in_quotes = 0;
 204
 205   pascal_one_char (c, stream, &in_quotes);
 206   if (in_quotes)
 207     fputs_filtered ("'", stream);
 208 }
 209
 210 void
 211 pascal_printchar (int c, struct type *type, struct ui_file *stream)
 212 {
 213   int in_quotes = 0;
 214
 215   pascal_one_char (c, stream, &in_quotes);
 216   if (in_quotes)
 217     fputs_filtered ("'", stream);
 218 }
 219
 220 /* Print the character string STRING, printing at most LENGTH characters.
 221    Printing stops early if the number hits print_max; repeat counts
 222    are printed as appropriate.  Print ellipses at the end if we
 223    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.  */
 224
 225 void
 226 pascal_printstr (struct ui_file *stream, struct type *type,
 227                  const gdb_byte *string, unsigned int length,
 228                  const char *encoding, int force_ellipses,
 229                  const struct value_print_options *options)
 230 {
 231   enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
 232   unsigned int i;
 233   unsigned int things_printed = 0;
 234   int in_quotes = 0;
 235   int need_comma = 0;
 236   int width;
 237
 238   /* Preserve TYPE's original type, just set its LENGTH.  */
 239   check_typedef (type);
 240   width = TYPE_LENGTH (type);
 241
 242   /* If the string was not truncated due to `set print elements', and
 243      the last byte of it is a null, we don't print that, in traditional C
 244      style.  */
 245   if ((!force_ellipses) && length > 0
 246         && extract_unsigned_integer (string + (length - 1) * width, width,
 247                                      byte_order) == 0)
 248     length--;
 249
 250   if (length == 0)
 251     {
 252       fputs_filtered ("''", stream);
 253       return;
 254     }
 255
 256   for (i = 0; i < length && things_printed < options->print_max; ++i)
 257     {
 258       /* Position of the character we are examining
 259          to see whether it is repeated.  */
 260       unsigned int rep1;
 261       /* Number of repetitions we have detected so far.  */
 262       unsigned int reps;
 263       unsigned long int current_char;
 264
 265       QUIT;
 266
 267       if (need_comma)
 268         {
 269           fputs_filtered (", ", stream);
 270           need_comma = 0;
 271         }
 272
 273       current_char = extract_unsigned_integer (string + i * width, width,
 274                                                byte_order);
 275
 276       rep1 = i + 1;
 277       reps = 1;
 278       while (rep1 < length
 279              && extract_unsigned_integer (string + rep1 * width, width,
 280                                           byte_order) == current_char)
 281         {
 282           ++rep1;
 283           ++reps;
 284         }
 285
 286       if (reps > options->repeat_count_threshold)
 287         {
 288           if (in_quotes)
 289             {
 290               fputs_filtered ("', ", stream);
 291               in_quotes = 0;
 292             }
 293           pascal_printchar (current_char, type, stream);
 294           fprintf_filtered (stream, " <repeats %u times>", reps);
 295           i = rep1 - 1;
 296           things_printed += options->repeat_count_threshold;
 297           need_comma = 1;
 298         }
 299       else
 300         {
 301           if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 302             {
 303               fputs_filtered ("'", stream);
 304               in_quotes = 1;
 305             }
 306           pascal_one_char (current_char, stream, &in_quotes);
 307           ++things_printed;
 308         }
 309     }
 310
 311   /* Terminate the quotes if necessary.  */
 312   if (in_quotes)
 313     fputs_filtered ("'", stream);
 314
 315   if (force_ellipses || i < length)
 316     fputs_filtered ("...", stream);
 317 }
 318 \f
 319
 320 /* Table mapping opcodes into strings for printing operators
 321    and precedences of the operators.  */
 322
 323 const struct op_print pascal_op_print_tab[] =
 324 {
 325   {",", BINOP_COMMA, PREC_COMMA, 0},
 326   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 327   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 328   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 329   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 330   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 331   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 332   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 333   {">=", BINOP_GEQ, PREC_ORDER, 0},
 334   {">", BINOP_GTR, PREC_ORDER, 0},
 335   {"<", BINOP_LESS, PREC_ORDER, 0},
 336   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 337   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 338   {"+", BINOP_ADD, PREC_ADD, 0},
 339   {"-", BINOP_SUB, PREC_ADD, 0},
 340   {"*", BINOP_MUL, PREC_MUL, 0},
 341   {"/", BINOP_DIV, PREC_MUL, 0},
 342   {"div", BINOP_INTDIV, PREC_MUL, 0},
 343   {"mod", BINOP_REM, PREC_MUL, 0},
 344   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 345   {"-", UNOP_NEG, PREC_PREFIX, 0},
 346   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 347   {"^", UNOP_IND, PREC_SUFFIX, 1},
 348   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 349   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 350   {NULL, OP_NULL, PREC_PREFIX, 0}
 351 };
 352 \f
 353 enum pascal_primitive_types {
 354   pascal_primitive_type_int,
 355   pascal_primitive_type_long,
 356   pascal_primitive_type_short,
 357   pascal_primitive_type_char,
 358   pascal_primitive_type_float,
 359   pascal_primitive_type_double,
 360   pascal_primitive_type_void,
 361   pascal_primitive_type_long_long,
 362   pascal_primitive_type_signed_char,
 363   pascal_primitive_type_unsigned_char,
 364   pascal_primitive_type_unsigned_short,
 365   pascal_primitive_type_unsigned_int,
 366   pascal_primitive_type_unsigned_long,
 367   pascal_primitive_type_unsigned_long_long,
 368   pascal_primitive_type_long_double,
 369   pascal_primitive_type_complex,
 370   pascal_primitive_type_double_complex,
 371   nr_pascal_primitive_types
 372 };
 373
 374 static void
 375 pascal_language_arch_info (struct gdbarch *gdbarch,
 376                            struct language_arch_info *lai)
 377 {
 378   const struct builtin_type *builtin = builtin_type (gdbarch);
 379
 380   lai->string_char_type = builtin->builtin_char;
 381   lai->primitive_type_vector
 382     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 383                               struct type *);
 384   lai->primitive_type_vector [pascal_primitive_type_int]
 385     = builtin->builtin_int;
 386   lai->primitive_type_vector [pascal_primitive_type_long]
 387     = builtin->builtin_long;
 388   lai->primitive_type_vector [pascal_primitive_type_short]
 389     = builtin->builtin_short;
 390   lai->primitive_type_vector [pascal_primitive_type_char]
 391     = builtin->builtin_char;
 392   lai->primitive_type_vector [pascal_primitive_type_float]
 393     = builtin->builtin_float;
 394   lai->primitive_type_vector [pascal_primitive_type_double]
 395     = builtin->builtin_double;
 396   lai->primitive_type_vector [pascal_primitive_type_void]
 397     = builtin->builtin_void;
 398   lai->primitive_type_vector [pascal_primitive_type_long_long]
 399     = builtin->builtin_long_long;
 400   lai->primitive_type_vector [pascal_primitive_type_signed_char]
 401     = builtin->builtin_signed_char;
 402   lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 403     = builtin->builtin_unsigned_char;
 404   lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 405     = builtin->builtin_unsigned_short;
 406   lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 407     = builtin->builtin_unsigned_int;
 408   lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 409     = builtin->builtin_unsigned_long;
 410   lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 411     = builtin->builtin_unsigned_long_long;
 412   lai->primitive_type_vector [pascal_primitive_type_long_double]
 413     = builtin->builtin_long_double;
 414   lai->primitive_type_vector [pascal_primitive_type_complex]
 415     = builtin->builtin_complex;
 416   lai->primitive_type_vector [pascal_primitive_type_double_complex]
 417     = builtin->builtin_double_complex;
 418
 419   lai->bool_type_symbol = "boolean";
 420   lai->bool_type_default = builtin->builtin_bool;
 421 }
 422
 423 static const char *p_extensions[] =
 424 {
 425   ".pas", ".p", ".pp", NULL
 426 };
 427
 428 extern const struct language_defn pascal_language_defn =
 429 {
 430   "pascal",                     /* Language name */
 431   "Pascal",
 432   language_pascal,
 433   range_check_on,
 434   case_sensitive_on,
 435   array_row_major,
 436   macro_expansion_no,
 437   p_extensions,
 438   &exp_descriptor_standard,
 439   pascal_parse,
 440   null_post_parser,
 441   pascal_printchar,             /* Print a character constant */
 442   pascal_printstr,              /* Function to print string constant */
 443   pascal_emit_char,             /* Print a single char */
 444   pascal_print_type,            /* Print a type using appropriate syntax */
 445   pascal_print_typedef,         /* Print a typedef using appropriate syntax */
 446   pascal_val_print,             /* Print a value using appropriate syntax */
 447   pascal_value_print,           /* Print a top-level value */
 448   default_read_var_value,       /* la_read_var_value */
 449   NULL,                         /* Language specific skip_trampoline */
 450   "this",                       /* name_of_this */
 451   false,                        /* la_store_sym_names_in_linkage_form_p */
 452   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 453   basic_lookup_transparent_type,/* lookup_transparent_type */
 454   NULL,                         /* Language specific symbol demangler */
 455   NULL,
 456   NULL,                         /* Language specific class_name_from_physname */
 457   pascal_op_print_tab,          /* expression operators for printing */
 458   1,                            /* c-style arrays */
 459   0,                            /* String lower bound */
 460   default_word_break_characters,
 461   default_collect_symbol_completion_matches,
 462   pascal_language_arch_info,
 463   default_print_array_index,
 464   default_pass_by_reference,
 465   default_get_string,
 466   c_watch_location_expression,
 467   NULL,                         /* la_compare_symbol_for_completion */
 468   iterate_over_symbols,
 469   default_search_name_hash,
 470   &default_varobj_ops,
 471   NULL,
 472   NULL,
 473   pascal_is_string_type_p,
 474   "{...}"                       /* la_struct_too_deep_ellipsis */
 475 };