gdb/p-lang.c

   1 /* Pascal language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2021 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 /* See p-lang.h.  */
  88
  89 int
  90 pascal_is_string_type (struct type *type,int *length_pos, int *length_size,
  91                        int *string_pos, struct type **char_type,
  92                        const char **arrayname)
  93 {
  94   if (type != NULL && type->code () == TYPE_CODE_STRUCT)
  95     {
  96       /* Old Borland type pascal strings from Free Pascal Compiler.  */
  97       /* Two fields: length and st.  */
  98       if (type->num_fields () == 2
  99           && TYPE_FIELD_NAME (type, 0)
 100           && strcmp (TYPE_FIELD_NAME (type, 0), "length") == 0
 101           && TYPE_FIELD_NAME (type, 1)
 102           && strcmp (TYPE_FIELD_NAME (type, 1), "st") == 0)
 103         {
 104           if (length_pos)
 105             *length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
 106           if (length_size)
 107             *length_size = TYPE_LENGTH (type->field (0).type ());
 108           if (string_pos)
 109             *string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 110           if (char_type)
 111             *char_type = TYPE_TARGET_TYPE (type->field (1).type ());
 112           if (arrayname)
 113             *arrayname = TYPE_FIELD_NAME (type, 1);
 114          return 2;
 115         };
 116       /* GNU pascal strings.  */
 117       /* Three fields: Capacity, length and schema$ or _p_schema.  */
 118       if (type->num_fields () == 3
 119           && TYPE_FIELD_NAME (type, 0)
 120           && strcmp (TYPE_FIELD_NAME (type, 0), "Capacity") == 0
 121           && TYPE_FIELD_NAME (type, 1)
 122           && strcmp (TYPE_FIELD_NAME (type, 1), "length") == 0)
 123         {
 124           if (length_pos)
 125             *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
 126           if (length_size)
 127             *length_size = TYPE_LENGTH (type->field (1).type ());
 128           if (string_pos)
 129             *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
 130           /* FIXME: how can I detect wide chars in GPC ??  */
 131           if (char_type)
 132             {
 133               *char_type = TYPE_TARGET_TYPE (type->field (2).type ());
 134
 135               if ((*char_type)->code () == TYPE_CODE_ARRAY)
 136                 *char_type = TYPE_TARGET_TYPE (*char_type);
 137             }
 138           if (arrayname)
 139             *arrayname = TYPE_FIELD_NAME (type, 2);
 140          return 3;
 141         };
 142     }
 143   return 0;
 144 }
 145
 146 /* See p-lang.h.  */
 147
 148 void
 149 pascal_language::print_one_char (int c, struct ui_file *stream,
 150                                  int *in_quotes) const
 151 {
 152   if (c == '\'' || ((unsigned int) c <= 0xff && (PRINT_LITERAL_FORM (c))))
 153     {
 154       if (!(*in_quotes))
 155         fputs_filtered ("'", stream);
 156       *in_quotes = 1;
 157       if (c == '\'')
 158         {
 159           fputs_filtered ("''", stream);
 160         }
 161       else
 162         fprintf_filtered (stream, "%c", c);
 163     }
 164   else
 165     {
 166       if (*in_quotes)
 167         fputs_filtered ("'", stream);
 168       *in_quotes = 0;
 169       fprintf_filtered (stream, "#%d", (unsigned int) c);
 170     }
 171 }
 172
 173 /* See language.h.  */
 174
 175 void
 176 pascal_language::printchar (int c, struct type *type,
 177                             struct ui_file *stream) const
 178 {
 179   int in_quotes = 0;
 180
 181   print_one_char (c, stream, &in_quotes);
 182   if (in_quotes)
 183     fputs_filtered ("'", stream);
 184 }
 185
 186 \f
 187
 188 /* Table mapping opcodes into strings for printing operators
 189    and precedences of the operators.  */
 190
 191 const struct op_print pascal_language::op_print_tab[] =
 192 {
 193   {",", BINOP_COMMA, PREC_COMMA, 0},
 194   {":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 195   {"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 196   {"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 197   {"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 198   {"=", BINOP_EQUAL, PREC_EQUAL, 0},
 199   {"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 200   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 201   {">=", BINOP_GEQ, PREC_ORDER, 0},
 202   {">", BINOP_GTR, PREC_ORDER, 0},
 203   {"<", BINOP_LESS, PREC_ORDER, 0},
 204   {"shr", BINOP_RSH, PREC_SHIFT, 0},
 205   {"shl", BINOP_LSH, PREC_SHIFT, 0},
 206   {"+", BINOP_ADD, PREC_ADD, 0},
 207   {"-", BINOP_SUB, PREC_ADD, 0},
 208   {"*", BINOP_MUL, PREC_MUL, 0},
 209   {"/", BINOP_DIV, PREC_MUL, 0},
 210   {"div", BINOP_INTDIV, PREC_MUL, 0},
 211   {"mod", BINOP_REM, PREC_MUL, 0},
 212   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 213   {"-", UNOP_NEG, PREC_PREFIX, 0},
 214   {"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 215   {"^", UNOP_IND, PREC_SUFFIX, 1},
 216   {"@", UNOP_ADDR, PREC_PREFIX, 0},
 217   {"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
 218   {NULL, OP_NULL, PREC_PREFIX, 0}
 219 };
 220 \f
 221
 222 /* See language.h.  */
 223
 224 void pascal_language::language_arch_info
 225         (struct gdbarch *gdbarch, struct language_arch_info *lai) const
 226 {
 227   const struct builtin_type *builtin = builtin_type (gdbarch);
 228
 229   /* Helper function to allow shorter lines below.  */
 230   auto add  = [&] (struct type * t)
 231   {
 232     lai->add_primitive_type (t);
 233   };
 234
 235   add (builtin->builtin_int);
 236   add (builtin->builtin_long);
 237   add (builtin->builtin_short);
 238   add (builtin->builtin_char);
 239   add (builtin->builtin_float);
 240   add (builtin->builtin_double);
 241   add (builtin->builtin_void);
 242   add (builtin->builtin_long_long);
 243   add (builtin->builtin_signed_char);
 244   add (builtin->builtin_unsigned_char);
 245   add (builtin->builtin_unsigned_short);
 246   add (builtin->builtin_unsigned_int);
 247   add (builtin->builtin_unsigned_long);
 248   add (builtin->builtin_unsigned_long_long);
 249   add (builtin->builtin_long_double);
 250   add (builtin->builtin_complex);
 251   add (builtin->builtin_double_complex);
 252
 253   lai->set_string_char_type (builtin->builtin_char);
 254   lai->set_bool_type (builtin->builtin_bool, "boolean");
 255 }
 256
 257 /* See language.h.  */
 258
 259 void
 260 pascal_language::printstr (struct ui_file *stream, struct type *elttype,
 261                            const gdb_byte *string, unsigned int length,
 262                            const char *encoding, int force_ellipses,
 263                            const struct value_print_options *options) const
 264 {
 265   enum bfd_endian byte_order = type_byte_order (elttype);
 266   unsigned int i;
 267   unsigned int things_printed = 0;
 268   int in_quotes = 0;
 269   int need_comma = 0;
 270   int width;
 271
 272   /* Preserve ELTTYPE's original type, just set its LENGTH.  */
 273   check_typedef (elttype);
 274   width = TYPE_LENGTH (elttype);
 275
 276   /* If the string was not truncated due to `set print elements', and
 277      the last byte of it is a null, we don't print that, in traditional C
 278      style.  */
 279   if ((!force_ellipses) && length > 0
 280       && extract_unsigned_integer (string + (length - 1) * width, width,
 281                                    byte_order) == 0)
 282     length--;
 283
 284   if (length == 0)
 285     {
 286       fputs_filtered ("''", stream);
 287       return;
 288     }
 289
 290   for (i = 0; i < length && things_printed < options->print_max; ++i)
 291     {
 292       /* Position of the character we are examining
 293          to see whether it is repeated.  */
 294       unsigned int rep1;
 295       /* Number of repetitions we have detected so far.  */
 296       unsigned int reps;
 297       unsigned long int current_char;
 298
 299       QUIT;
 300
 301       if (need_comma)
 302         {
 303           fputs_filtered (", ", stream);
 304           need_comma = 0;
 305         }
 306
 307       current_char = extract_unsigned_integer (string + i * width, width,
 308                                                byte_order);
 309
 310       rep1 = i + 1;
 311       reps = 1;
 312       while (rep1 < length
 313              && extract_unsigned_integer (string + rep1 * width, width,
 314                                           byte_order) == current_char)
 315         {
 316           ++rep1;
 317           ++reps;
 318         }
 319
 320       if (reps > options->repeat_count_threshold)
 321         {
 322           if (in_quotes)
 323             {
 324               fputs_filtered ("', ", stream);
 325               in_quotes = 0;
 326             }
 327           printchar (current_char, elttype, stream);
 328           fprintf_filtered (stream, " %p[<repeats %u times>%p]",
 329                             metadata_style.style ().ptr (),
 330                             reps, nullptr);
 331           i = rep1 - 1;
 332           things_printed += options->repeat_count_threshold;
 333           need_comma = 1;
 334         }
 335       else
 336         {
 337           if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 338             {
 339               fputs_filtered ("'", stream);
 340               in_quotes = 1;
 341             }
 342           print_one_char (current_char, stream, &in_quotes);
 343           ++things_printed;
 344         }
 345     }
 346
 347   /* Terminate the quotes if necessary.  */
 348   if (in_quotes)
 349     fputs_filtered ("'", stream);
 350
 351   if (force_ellipses || i < length)
 352     fputs_filtered ("...", stream);
 353 }
 354
 355 /* Single instance of the Pascal language class.  */
 356
 357 static pascal_language pascal_language_defn;