gdb/p-lang.c

   1 /* Pascal language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2018 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 static void pascal_one_char (int, struct ui_file *, int *);
 154
 155 /* Print the character C on STREAM as part of the contents of a literal
 156    string.
 157    In_quotes is reset to 0 if a char is written with #4 notation.  */
 158
 159 static void
 160 pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
 161 {
 162   if (c == '\'' || ((unsigned int) c <= 0xff && (PRINT_LITERAL_FORM (c))))
 163     {
 164       if (!(*in_quotes))
 165         fputs_filtered ("'", stream);
 166       *in_quotes = 1;
 167       if (c == '\'')
 168         {
 169           fputs_filtered ("''", stream);
 170         }
 171       else
 172         fprintf_filtered (stream, "%c", c);
 173     }
 174   else
 175     {
 176       if (*in_quotes)
 177         fputs_filtered ("'", stream);
 178       *in_quotes = 0;
 179       fprintf_filtered (stream, "#%d", (unsigned int) c);
 180     }
 181 }
 182
 183 static void pascal_emit_char (int c, struct type *type,
 184                               struct ui_file *stream, int quoter);
 185
 186 /* Print the character C on STREAM as part of the contents of a literal
 187    string whose delimiter is QUOTER.  Note that that format for printing
 188    characters and strings is language specific.  */
 189
 190 static void
 191 pascal_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
 192 {
 193   int in_quotes = 0;
 194
 195   pascal_one_char (c, stream, &in_quotes);
 196   if (in_quotes)
 197     fputs_filtered ("'", stream);
 198 }
 199
 200 void
 201 pascal_printchar (int c, struct type *type, struct ui_file *stream)
 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 /* Print the character string STRING, printing at most LENGTH characters.
 211    Printing stops early if the number hits print_max; repeat counts
 212    are printed as appropriate.  Print ellipses at the end if we
 213    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.  */
 214
 215 void
 216 pascal_printstr (struct ui_file *stream, struct type *type,
 217                  const gdb_byte *string, unsigned int length,
 218                  const char *encoding, int force_ellipses,
 219                  const struct value_print_options *options)
 220 {
 221   enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
 222   unsigned int i;
 223   unsigned int things_printed = 0;
 224   int in_quotes = 0;
 225   int need_comma = 0;
 226   int width;
 227
 228   /* Preserve TYPE's original type, just set its LENGTH.  */
 229   check_typedef (type);
 230   width = TYPE_LENGTH (type);
 231
 232   /* If the string was not truncated due to `set print elements', and
 233      the last byte of it is a null, we don't print that, in traditional C
 234      style.  */
 235   if ((!force_ellipses) && length > 0
 236         && extract_unsigned_integer (string + (length - 1) * width, width,
 237                                      byte_order) == 0)
 238     length--;
 239
 240   if (length == 0)
 241     {
 242       fputs_filtered ("''", stream);
 243       return;
 244     }
 245
 246   for (i = 0; i < length && things_printed < options->print_max; ++i)
 247     {
 248       /* Position of the character we are examining
 249          to see whether it is repeated.  */
 250       unsigned int rep1;
 251       /* Number of repetitions we have detected so far.  */
 252       unsigned int reps;
 253       unsigned long int current_char;
 254
 255       QUIT;
 256
 257       if (need_comma)
 258         {
 259           fputs_filtered (", ", stream);
 260           need_comma = 0;
 261         }
 262
 263       current_char = extract_unsigned_integer (string + i * width, width,
 264                                                byte_order);
 265
 266       rep1 = i + 1;
 267       reps = 1;
 268       while (rep1 < length
 269              && extract_unsigned_integer (string + rep1 * width, width,
 270                                           byte_order) == current_char)
 271         {
 272           ++rep1;
 273           ++reps;
 274         }
 275
 276       if (reps > options->repeat_count_threshold)
 277         {
 278           if (in_quotes)
 279             {
 280               fputs_filtered ("', ", stream);
 281               in_quotes = 0;
 282             }
 283           pascal_printchar (current_char, type, stream);
 284           fprintf_filtered (stream, " <repeats %u times>", reps);
 285           i = rep1 - 1;
 286           things_printed += options->repeat_count_threshold;
 287           need_comma = 1;
 288         }
 289       else
 290         {
 291           if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 292             {
 293               fputs_filtered ("'", stream);
 294               in_quotes = 1;
 295             }
 296           pascal_one_char (current_char, stream, &in_quotes);
 297           ++things_printed;
 298         }
 299     }
 300
 301   /* Terminate the quotes if necessary.  */
 302   if (in_quotes)
 303     fputs_filtered ("'", stream);
 304
 305   if (force_ellipses || i < length)
 306     fputs_filtered ("...", stream);
 307 }
 308 \f
 309
 310 /* Table mapping opcodes into strings for printing operators
 311    and precedences of the operators.  */
 312
 313 const struct op_print pascal_op_print_tab[] =
 314 {
 315   {",", BINOP_COMMA, PREC_COMMA, 0},
 316   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 317   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 318   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 319   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 320   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 321   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 322   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 323   {">=", BINOP_GEQ, PREC_ORDER, 0},
 324   {">", BINOP_GTR, PREC_ORDER, 0},
 325   {"<", BINOP_LESS, PREC_ORDER, 0},
 326   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 327   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 328   {"+", BINOP_ADD, PREC_ADD, 0},
 329   {"-", BINOP_SUB, PREC_ADD, 0},
 330   {"*", BINOP_MUL, PREC_MUL, 0},
 331   {"/", BINOP_DIV, PREC_MUL, 0},
 332   {"div", BINOP_INTDIV, PREC_MUL, 0},
 333   {"mod", BINOP_REM, PREC_MUL, 0},
 334   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 335   {"-", UNOP_NEG, PREC_PREFIX, 0},
 336   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 337   {"^", UNOP_IND, PREC_SUFFIX, 1},
 338   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 339   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 340   {NULL, OP_NULL, PREC_PREFIX, 0}
 341 };
 342 \f
 343 enum pascal_primitive_types {
 344   pascal_primitive_type_int,
 345   pascal_primitive_type_long,
 346   pascal_primitive_type_short,
 347   pascal_primitive_type_char,
 348   pascal_primitive_type_float,
 349   pascal_primitive_type_double,
 350   pascal_primitive_type_void,
 351   pascal_primitive_type_long_long,
 352   pascal_primitive_type_signed_char,
 353   pascal_primitive_type_unsigned_char,
 354   pascal_primitive_type_unsigned_short,
 355   pascal_primitive_type_unsigned_int,
 356   pascal_primitive_type_unsigned_long,
 357   pascal_primitive_type_unsigned_long_long,
 358   pascal_primitive_type_long_double,
 359   pascal_primitive_type_complex,
 360   pascal_primitive_type_double_complex,
 361   nr_pascal_primitive_types
 362 };
 363
 364 static void
 365 pascal_language_arch_info (struct gdbarch *gdbarch,
 366                            struct language_arch_info *lai)
 367 {
 368   const struct builtin_type *builtin = builtin_type (gdbarch);
 369
 370   lai->string_char_type = builtin->builtin_char;
 371   lai->primitive_type_vector
 372     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 373                               struct type *);
 374   lai->primitive_type_vector [pascal_primitive_type_int]
 375     = builtin->builtin_int;
 376   lai->primitive_type_vector [pascal_primitive_type_long]
 377     = builtin->builtin_long;
 378   lai->primitive_type_vector [pascal_primitive_type_short]
 379     = builtin->builtin_short;
 380   lai->primitive_type_vector [pascal_primitive_type_char]
 381     = builtin->builtin_char;
 382   lai->primitive_type_vector [pascal_primitive_type_float]
 383     = builtin->builtin_float;
 384   lai->primitive_type_vector [pascal_primitive_type_double]
 385     = builtin->builtin_double;
 386   lai->primitive_type_vector [pascal_primitive_type_void]
 387     = builtin->builtin_void;
 388   lai->primitive_type_vector [pascal_primitive_type_long_long]
 389     = builtin->builtin_long_long;
 390   lai->primitive_type_vector [pascal_primitive_type_signed_char]
 391     = builtin->builtin_signed_char;
 392   lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 393     = builtin->builtin_unsigned_char;
 394   lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 395     = builtin->builtin_unsigned_short;
 396   lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 397     = builtin->builtin_unsigned_int;
 398   lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 399     = builtin->builtin_unsigned_long;
 400   lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 401     = builtin->builtin_unsigned_long_long;
 402   lai->primitive_type_vector [pascal_primitive_type_long_double]
 403     = builtin->builtin_long_double;
 404   lai->primitive_type_vector [pascal_primitive_type_complex]
 405     = builtin->builtin_complex;
 406   lai->primitive_type_vector [pascal_primitive_type_double_complex]
 407     = builtin->builtin_double_complex;
 408
 409   lai->bool_type_symbol = "boolean";
 410   lai->bool_type_default = builtin->builtin_bool;
 411 }
 412
 413 static const char *p_extensions[] =
 414 {
 415   ".pas", ".p", ".pp", NULL
 416 };
 417
 418 extern const struct language_defn pascal_language_defn =
 419 {
 420   "pascal",                     /* Language name */
 421   "Pascal",
 422   language_pascal,
 423   range_check_on,
 424   case_sensitive_on,
 425   array_row_major,
 426   macro_expansion_no,
 427   p_extensions,
 428   &exp_descriptor_standard,
 429   pascal_parse,
 430   pascal_yyerror,
 431   null_post_parser,
 432   pascal_printchar,             /* Print a character constant */
 433   pascal_printstr,              /* Function to print string constant */
 434   pascal_emit_char,             /* Print a single char */
 435   pascal_print_type,            /* Print a type using appropriate syntax */
 436   pascal_print_typedef,         /* Print a typedef using appropriate syntax */
 437   pascal_val_print,             /* Print a value using appropriate syntax */
 438   pascal_value_print,           /* Print a top-level value */
 439   default_read_var_value,       /* la_read_var_value */
 440   NULL,                         /* Language specific skip_trampoline */
 441   "this",                       /* name_of_this */
 442   false,                        /* la_store_sym_names_in_linkage_form_p */
 443   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 444   basic_lookup_transparent_type,/* lookup_transparent_type */
 445   NULL,                         /* Language specific symbol demangler */
 446   NULL,
 447   NULL,                         /* Language specific class_name_from_physname */
 448   pascal_op_print_tab,          /* expression operators for printing */
 449   1,                            /* c-style arrays */
 450   0,                            /* String lower bound */
 451   default_word_break_characters,
 452   default_collect_symbol_completion_matches,
 453   pascal_language_arch_info,
 454   default_print_array_index,
 455   default_pass_by_reference,
 456   default_get_string,
 457   c_watch_location_expression,
 458   NULL,                         /* la_compare_symbol_for_completion */
 459   iterate_over_symbols,
 460   default_search_name_hash,
 461   &default_varobj_ops,
 462   NULL,
 463   NULL,
 464   LANG_MAGIC
 465 };