gdb/p-lang.c

   1 /* Pascal language support routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2022 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 (0).name ()
 100           && strcmp (type->field (0).name (), "length") == 0
 101           && type->field (1).name ()
 102           && strcmp (type->field (1).name (), "st") == 0)
 103         {
 104           if (length_pos)
 105             *length_pos = type->field (0).loc_bitpos () / 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 (1).loc_bitpos () / TARGET_CHAR_BIT;
 110           if (char_type)
 111             *char_type = TYPE_TARGET_TYPE (type->field (1).type ());
 112           if (arrayname)
 113             *arrayname = type->field (1).name ();
 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 (0).name ()
 120           && strcmp (type->field (0).name (), "Capacity") == 0
 121           && type->field (1).name ()
 122           && strcmp (type->field (1).name (), "length") == 0)
 123         {
 124           if (length_pos)
 125             *length_pos = type->field (1).loc_bitpos () / 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 (2).loc_bitpos () / 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 (2).name ();
 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         gdb_puts ("'", stream);
 156       *in_quotes = 1;
 157       if (c == '\'')
 158         {
 159           gdb_puts ("''", stream);
 160         }
 161       else
 162         gdb_printf (stream, "%c", c);
 163     }
 164   else
 165     {
 166       if (*in_quotes)
 167         gdb_puts ("'", stream);
 168       *in_quotes = 0;
 169       gdb_printf (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     gdb_puts ("'", stream);
 184 }
 185
 186 \f
 187
 188 /* See language.h.  */
 189
 190 void pascal_language::language_arch_info
 191         (struct gdbarch *gdbarch, struct language_arch_info *lai) const
 192 {
 193   const struct builtin_type *builtin = builtin_type (gdbarch);
 194
 195   /* Helper function to allow shorter lines below.  */
 196   auto add  = [&] (struct type * t)
 197   {
 198     lai->add_primitive_type (t);
 199   };
 200
 201   add (builtin->builtin_int);
 202   add (builtin->builtin_long);
 203   add (builtin->builtin_short);
 204   add (builtin->builtin_char);
 205   add (builtin->builtin_float);
 206   add (builtin->builtin_double);
 207   add (builtin->builtin_void);
 208   add (builtin->builtin_long_long);
 209   add (builtin->builtin_signed_char);
 210   add (builtin->builtin_unsigned_char);
 211   add (builtin->builtin_unsigned_short);
 212   add (builtin->builtin_unsigned_int);
 213   add (builtin->builtin_unsigned_long);
 214   add (builtin->builtin_unsigned_long_long);
 215   add (builtin->builtin_long_double);
 216   add (builtin->builtin_complex);
 217   add (builtin->builtin_double_complex);
 218
 219   lai->set_string_char_type (builtin->builtin_char);
 220   lai->set_bool_type (builtin->builtin_bool, "boolean");
 221 }
 222
 223 /* See language.h.  */
 224
 225 void
 226 pascal_language::printstr (struct ui_file *stream, struct type *elttype,
 227                            const gdb_byte *string, unsigned int length,
 228                            const char *encoding, int force_ellipses,
 229                            const struct value_print_options *options) const
 230 {
 231   enum bfd_endian byte_order = type_byte_order (elttype);
 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 ELTTYPE's original type, just set its LENGTH.  */
 239   check_typedef (elttype);
 240   width = TYPE_LENGTH (elttype);
 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       gdb_puts ("''", 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           gdb_puts (", ", 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               gdb_puts ("', ", stream);
 291               in_quotes = 0;
 292             }
 293           printchar (current_char, elttype, stream);
 294           gdb_printf (stream, " %p[<repeats %u times>%p]",
 295                       metadata_style.style ().ptr (),
 296                       reps, nullptr);
 297           i = rep1 - 1;
 298           things_printed += options->repeat_count_threshold;
 299           need_comma = 1;
 300         }
 301       else
 302         {
 303           if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
 304             {
 305               gdb_puts ("'", stream);
 306               in_quotes = 1;
 307             }
 308           print_one_char (current_char, stream, &in_quotes);
 309           ++things_printed;
 310         }
 311     }
 312
 313   /* Terminate the quotes if necessary.  */
 314   if (in_quotes)
 315     gdb_puts ("'", stream);
 316
 317   if (force_ellipses || i < length)
 318     gdb_puts ("...", stream);
 319 }
 320
 321 /* Single instance of the Pascal language class.  */
 322
 323 static pascal_language pascal_language_defn;