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 #include "gdbarch.h"
  35
  36 /* All GPC versions until now (2007-09-27) also define a symbol called
  37    '_p_initialize'.  Check for the presence of this symbol first.  */
  38 static const char GPC_P_INITIALIZE[] = "_p_initialize";
  39
  40 /* The name of the symbol that GPC uses as the name of the main
  41    procedure (since version 20050212).  */
  42 static const char GPC_MAIN_PROGRAM_NAME_1[] = "_p__M0_main_program";
  43
  44 /* Older versions of GPC (versions older than 20050212) were using
  45    a different name for the main procedure.  */
  46 static const char GPC_MAIN_PROGRAM_NAME_2[] = "pascal_main_program";
  47
  48 /* Function returning the special symbol name used
  49    by GPC for the main procedure in the main program
  50    if it is found in minimal symbol list.
  51    This function tries to find minimal symbols generated by GPC
  52    so that it finds the even if the program was compiled
  53    without debugging information.
  54    According to information supplied by Waldeck Hebisch,
  55    this should work for all versions posterior to June 2000.  */
  56
  57 const char *
  58 pascal_main_name (void)
  59 {
  60   struct bound_minimal_symbol msym;
  61
  62   msym = lookup_minimal_symbol (GPC_P_INITIALIZE, NULL, NULL);
  63
  64   /*  If '_p_initialize' was not found, the main program is likely not
  65      written in Pascal.  */
  66   if (msym.minsym == NULL)
  67     return NULL;
  68
  69   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_1, NULL, NULL);
  70   if (msym.minsym != NULL)
  71     {
  72       return GPC_MAIN_PROGRAM_NAME_1;
  73     }
  74
  75   msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_2, NULL, NULL);
  76   if (msym.minsym != NULL)
  77     {
  78       return GPC_MAIN_PROGRAM_NAME_2;
  79     }
  80
  81   /*  No known entry procedure found, the main program is probably
  82       not compiled with GPC.  */
  83   return NULL;
  84 }
  85
  86 /* Determines if type TYPE is a pascal string type.
  87    Returns a positive value if the type is a known pascal string type.
  88    This function is used by p-valprint.c code to allow better string display.
  89    If it is a pascal string type, then it also sets info needed
  90    to get the length and the data of the string
  91    length_pos, length_size and string_pos are given in bytes.
  92    char_size gives the element size in bytes.
  93    FIXME: if the position or the size of these fields
  94    are not multiple of TARGET_CHAR_BIT then the results are wrong
  95    but this does not happen for Free Pascal nor for GPC.  */
  96 int
  97 is_pascal_string_type (struct type *type,int *length_pos,
  98                        int *length_size, int *string_pos,
  99                        struct type **char_type,
 100                        const char **arrayname)
 101 {
 102   if (type != NULL && TYPE_CODE (type) == TYPE_CODE_STRUCT)
 103     {
 104       /* Old Borland type pascal strings from Free Pascal Compiler.  */
 105       /* Two fields: length and st.  */
 106       if (TYPE_NFIELDS (type) == 2
 107           && TYPE_FIELD_NAME (type, 0)
 108           && strcmp (TYPE_FIELD_NAME (type, 0), "length") == 0
 109           && TYPE_FIELD_NAME (type, 1)
 110           && strcmp (TYPE_FIELD_NAME (type, 1), "st") == 0)
 111         {
 112           if (length_pos)
 113             *length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
 114           if (length_size)
 115             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0));
 116           if (string_pos)
 117             *string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 118           if (char_type)
 119             *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 1));
 120           if (arrayname)
 121             *arrayname = TYPE_FIELD_NAME (type, 1);
 122          return 2;
 123         };
 124       /* GNU pascal strings.  */
 125       /* Three fields: Capacity, length and schema$ or _p_schema.  */
 126       if (TYPE_NFIELDS (type) == 3
 127           && TYPE_FIELD_NAME (type, 0)
 128           && strcmp (TYPE_FIELD_NAME (type, 0), "Capacity") == 0
 129           && TYPE_FIELD_NAME (type, 1)
 130           && strcmp (TYPE_FIELD_NAME (type, 1), "length") == 0)
 131         {
 132           if (length_pos)
 133             *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 134           if (length_size)
 135             *length_size = TYPE_LENGTH (TYPE_FIELD_TYPE (type, 1));
 136           if (string_pos)
 137             *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
 138           /* FIXME: how can I detect wide chars in GPC ??  */
 139           if (char_type)
 140             {
 141               *char_type = TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 2));
 142
 143               if (TYPE_CODE (*char_type) == TYPE_CODE_ARRAY)
 144                 *char_type = TYPE_TARGET_TYPE (*char_type);
 145             }
 146           if (arrayname)
 147             *arrayname = TYPE_FIELD_NAME (type, 2);
 148          return 3;
 149         };
 150     }
 151   return 0;
 152 }
 153
 154 /* This is a wrapper around IS_PASCAL_STRING_TYPE that returns true if TYPE
 155    is a string.  */
 156
 157 static bool
 158 pascal_is_string_type_p (struct type *type)
 159 {
 160   return is_pascal_string_type (type, nullptr, nullptr, nullptr,
 161                                 nullptr, nullptr) > 0;
 162 }
 163
 164 static void pascal_one_char (int, struct ui_file *, int *);
 165
 166 /* Print the character C on STREAM as part of the contents of a literal
 167    string.
 168    In_quotes is reset to 0 if a char is written with #4 notation.  */
 169
 170 static void
 171 pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
 172 {
 173   if (c == '\'' || ((unsigned int) c <= 0xff && (PRINT_LITERAL_FORM (c))))
 174     {
 175       if (!(*in_quotes))
 176         fputs_filtered ("'", stream);
 177       *in_quotes = 1;
 178       if (c == '\'')
 179         {
 180           fputs_filtered ("''", stream);
 181         }
 182       else
 183         fprintf_filtered (stream, "%c", c);
 184     }
 185   else
 186     {
 187       if (*in_quotes)
 188         fputs_filtered ("'", stream);
 189       *in_quotes = 0;
 190       fprintf_filtered (stream, "#%d", (unsigned int) c);
 191     }
 192 }
 193
 194 static void pascal_emit_char (int c, struct type *type,
 195                               struct ui_file *stream, int quoter);
 196
 197 /* Print the character C on STREAM as part of the contents of a literal
 198    string whose delimiter is QUOTER.  Note that that format for printing
 199    characters and strings is language specific.  */
 200
 201 static void
 202 pascal_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
 203 {
 204   int in_quotes = 0;
 205
 206   pascal_one_char (c, stream, &in_quotes);
 207   if (in_quotes)
 208     fputs_filtered ("'", stream);
 209 }
 210
 211 void
 212 pascal_printchar (int c, struct type *type, struct ui_file *stream)
 213 {
 214   int in_quotes = 0;
 215
 216   pascal_one_char (c, stream, &in_quotes);
 217   if (in_quotes)
 218     fputs_filtered ("'", stream);
 219 }
 220
 221 /* Print the character string STRING, printing at most LENGTH characters.
 222    Printing stops early if the number hits print_max; repeat counts
 223    are printed as appropriate.  Print ellipses at the end if we
 224    had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.  */
 225
 226 void
 227 pascal_printstr (struct ui_file *stream, struct type *type,
 228                  const gdb_byte *string, unsigned int length,
 229                  const char *encoding, int force_ellipses,
 230                  const struct value_print_options *options)
 231 {
 232   enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
 233   unsigned int i;
 234   unsigned int things_printed = 0;
 235   int in_quotes = 0;
 236   int need_comma = 0;
 237   int width;
 238
 239   /* Preserve TYPE's original type, just set its LENGTH.  */
 240   check_typedef (type);
 241   width = TYPE_LENGTH (type);
 242
 243   /* If the string was not truncated due to `set print elements', and
 244      the last byte of it is a null, we don't print that, in traditional C
 245      style.  */
 246   if ((!force_ellipses) && length > 0
 247         && extract_unsigned_integer (string + (length - 1) * width, width,
 248                                      byte_order) == 0)
 249     length--;
 250
 251   if (length == 0)
 252     {
 253       fputs_filtered ("''", stream);
 254       return;
 255     }
 256
 257   for (i = 0; i < length && things_printed < options->print_max; ++i)
 258     {
 259       /* Position of the character we are examining
 260          to see whether it is repeated.  */
 261       unsigned int rep1;
 262       /* Number of repetitions we have detected so far.  */
 263       unsigned int reps;
 264       unsigned long int current_char;
 265
 266       QUIT;
 267
 268       if (need_comma)
 269         {
 270           fputs_filtered (", ", stream);
 271           need_comma = 0;
 272         }
 273
 274       current_char = extract_unsigned_integer (string + i * width, width,
 275                                                byte_order);
 276
 277       rep1 = i + 1;
 278       reps = 1;
 279       while (rep1 < length
 280              && extract_unsigned_integer (string + rep1 * width, width,
 281                                           byte_order) == current_char)
 282         {
 283           ++rep1;
 284           ++reps;
 285         }
 286
 287       if (reps > options->repeat_count_threshold)
 288         {
 289           if (in_quotes)
 290             {
 291               fputs_filtered ("', ", stream);
 292               in_quotes = 0;
 293             }
 294           pascal_printchar (current_char, type, stream);
 295           fprintf_filtered (stream, " <repeats %u times>", reps);
 296           i = rep1 - 1;
 297           things_printed += options->repeat_count_threshold;
 298           need_comma = 1;
 299         }
 300       else
 301         {
 302           if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 303             {
 304               fputs_filtered ("'", stream);
 305               in_quotes = 1;
 306             }
 307           pascal_one_char (current_char, stream, &in_quotes);
 308           ++things_printed;
 309         }
 310     }
 311
 312   /* Terminate the quotes if necessary.  */
 313   if (in_quotes)
 314     fputs_filtered ("'", stream);
 315
 316   if (force_ellipses || i < length)
 317     fputs_filtered ("...", stream);
 318 }
 319 \f
 320
 321 /* Table mapping opcodes into strings for printing operators
 322    and precedences of the operators.  */
 323
 324 const struct op_print pascal_op_print_tab[] =
 325 {
 326   {",", BINOP_COMMA, PREC_COMMA, 0},
 327   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 328   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 329   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 330   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 331   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 332   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 333   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 334   {">=", BINOP_GEQ, PREC_ORDER, 0},
 335   {">", BINOP_GTR, PREC_ORDER, 0},
 336   {"<", BINOP_LESS, PREC_ORDER, 0},
 337   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 338   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 339   {"+", BINOP_ADD, PREC_ADD, 0},
 340   {"-", BINOP_SUB, PREC_ADD, 0},
 341   {"*", BINOP_MUL, PREC_MUL, 0},
 342   {"/", BINOP_DIV, PREC_MUL, 0},
 343   {"div", BINOP_INTDIV, PREC_MUL, 0},
 344   {"mod", BINOP_REM, PREC_MUL, 0},
 345   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 346   {"-", UNOP_NEG, PREC_PREFIX, 0},
 347   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 348   {"^", UNOP_IND, PREC_SUFFIX, 1},
 349   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 350   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 351   {NULL, OP_NULL, PREC_PREFIX, 0}
 352 };
 353 \f
 354 enum pascal_primitive_types {
 355   pascal_primitive_type_int,
 356   pascal_primitive_type_long,
 357   pascal_primitive_type_short,
 358   pascal_primitive_type_char,
 359   pascal_primitive_type_float,
 360   pascal_primitive_type_double,
 361   pascal_primitive_type_void,
 362   pascal_primitive_type_long_long,
 363   pascal_primitive_type_signed_char,
 364   pascal_primitive_type_unsigned_char,
 365   pascal_primitive_type_unsigned_short,
 366   pascal_primitive_type_unsigned_int,
 367   pascal_primitive_type_unsigned_long,
 368   pascal_primitive_type_unsigned_long_long,
 369   pascal_primitive_type_long_double,
 370   pascal_primitive_type_complex,
 371   pascal_primitive_type_double_complex,
 372   nr_pascal_primitive_types
 373 };
 374
 375 static void
 376 pascal_language_arch_info (struct gdbarch *gdbarch,
 377                            struct language_arch_info *lai)
 378 {
 379   const struct builtin_type *builtin = builtin_type (gdbarch);
 380
 381   lai->string_char_type = builtin->builtin_char;
 382   lai->primitive_type_vector
 383     = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_pascal_primitive_types + 1,
 384                               struct type *);
 385   lai->primitive_type_vector [pascal_primitive_type_int]
 386     = builtin->builtin_int;
 387   lai->primitive_type_vector [pascal_primitive_type_long]
 388     = builtin->builtin_long;
 389   lai->primitive_type_vector [pascal_primitive_type_short]
 390     = builtin->builtin_short;
 391   lai->primitive_type_vector [pascal_primitive_type_char]
 392     = builtin->builtin_char;
 393   lai->primitive_type_vector [pascal_primitive_type_float]
 394     = builtin->builtin_float;
 395   lai->primitive_type_vector [pascal_primitive_type_double]
 396     = builtin->builtin_double;
 397   lai->primitive_type_vector [pascal_primitive_type_void]
 398     = builtin->builtin_void;
 399   lai->primitive_type_vector [pascal_primitive_type_long_long]
 400     = builtin->builtin_long_long;
 401   lai->primitive_type_vector [pascal_primitive_type_signed_char]
 402     = builtin->builtin_signed_char;
 403   lai->primitive_type_vector [pascal_primitive_type_unsigned_char]
 404     = builtin->builtin_unsigned_char;
 405   lai->primitive_type_vector [pascal_primitive_type_unsigned_short]
 406     = builtin->builtin_unsigned_short;
 407   lai->primitive_type_vector [pascal_primitive_type_unsigned_int]
 408     = builtin->builtin_unsigned_int;
 409   lai->primitive_type_vector [pascal_primitive_type_unsigned_long]
 410     = builtin->builtin_unsigned_long;
 411   lai->primitive_type_vector [pascal_primitive_type_unsigned_long_long]
 412     = builtin->builtin_unsigned_long_long;
 413   lai->primitive_type_vector [pascal_primitive_type_long_double]
 414     = builtin->builtin_long_double;
 415   lai->primitive_type_vector [pascal_primitive_type_complex]
 416     = builtin->builtin_complex;
 417   lai->primitive_type_vector [pascal_primitive_type_double_complex]
 418     = builtin->builtin_double_complex;
 419
 420   lai->bool_type_symbol = "boolean";
 421   lai->bool_type_default = builtin->builtin_bool;
 422 }
 423
 424 static const char *p_extensions[] =
 425 {
 426   ".pas", ".p", ".pp", NULL
 427 };
 428
 429 extern const struct language_defn pascal_language_defn =
 430 {
 431   "pascal",                     /* Language name */
 432   "Pascal",
 433   language_pascal,
 434   range_check_on,
 435   case_sensitive_on,
 436   array_row_major,
 437   macro_expansion_no,
 438   p_extensions,
 439   &exp_descriptor_standard,
 440   pascal_parse,
 441   null_post_parser,
 442   pascal_printchar,             /* Print a character constant */
 443   pascal_printstr,              /* Function to print string constant */
 444   pascal_emit_char,             /* Print a single char */
 445   pascal_print_type,            /* Print a type using appropriate syntax */
 446   pascal_print_typedef,         /* Print a typedef using appropriate syntax */
 447   pascal_val_print,             /* Print a value using appropriate syntax */
 448   pascal_value_print,           /* Print a top-level value */
 449   default_read_var_value,       /* la_read_var_value */
 450   NULL,                         /* Language specific skip_trampoline */
 451   "this",                       /* name_of_this */
 452   false,                        /* la_store_sym_names_in_linkage_form_p */
 453   basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */
 454   basic_lookup_transparent_type,/* lookup_transparent_type */
 455   NULL,                         /* Language specific symbol demangler */
 456   NULL,
 457   NULL,                         /* Language specific class_name_from_physname */
 458   pascal_op_print_tab,          /* expression operators for printing */
 459   1,                            /* c-style arrays */
 460   0,                            /* String lower bound */
 461   default_word_break_characters,
 462   default_collect_symbol_completion_matches,
 463   pascal_language_arch_info,
 464   default_print_array_index,
 465   default_pass_by_reference,
 466   default_get_string,
 467   c_watch_location_expression,
 468   NULL,                         /* la_compare_symbol_for_completion */
 469   iterate_over_symbols,
 470   default_search_name_hash,
 471   &default_varobj_ops,
 472   NULL,
 473   NULL,
 474   pascal_is_string_type_p,
 475   "{...}"                       /* la_struct_too_deep_ellipsis */
 476 };