gdb/c-lang.c

   1 /* C language support routines for GDB, the GNU debugger.
   2    Copyright 1992, 1993, 1994 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22 #include "symtab.h"
  23 #include "gdbtypes.h"
  24 #include "expression.h"
  25 #include "parser-defs.h"
  26 #include "language.h"
  27 #include "c-lang.h"
  28
  29 extern void _initialize_c_language PARAMS ((void));
  30 static void c_emit_char PARAMS ((int c, GDB_FILE * stream, int quoter));
  31
  32 /* Print the character C on STREAM as part of the contents of a literal
  33    string whose delimiter is QUOTER.  Note that that format for printing
  34    characters and strings is language specific. */
  35
  36 static void
  37 c_emit_char (c, stream, quoter)
  38      register int c;
  39      GDB_FILE *stream;
  40      int quoter;
  41 {
  42   c &= 0xFF;                    /* Avoid sign bit follies */
  43
  44   if (PRINT_LITERAL_FORM (c))
  45     {
  46       if (c == '\\' || c == quoter)
  47         {
  48           fputs_filtered ("\\", stream);
  49         }
  50       fprintf_filtered (stream, "%c", c);
  51     }
  52   else
  53     {
  54       switch (c)
  55         {
  56         case '\n':
  57           fputs_filtered ("\\n", stream);
  58           break;
  59         case '\b':
  60           fputs_filtered ("\\b", stream);
  61           break;
  62         case '\t':
  63           fputs_filtered ("\\t", stream);
  64           break;
  65         case '\f':
  66           fputs_filtered ("\\f", stream);
  67           break;
  68         case '\r':
  69           fputs_filtered ("\\r", stream);
  70           break;
  71         case '\033':
  72           fputs_filtered ("\\e", stream);
  73           break;
  74         case '\007':
  75           fputs_filtered ("\\a", stream);
  76           break;
  77         default:
  78           fprintf_filtered (stream, "\\%.3o", (unsigned int) c);
  79           break;
  80         }
  81     }
  82 }
  83
  84 void
  85 c_printchar (c, stream)
  86      int c;
  87      GDB_FILE *stream;
  88 {
  89   fputc_filtered ('\'', stream);
  90   LA_EMIT_CHAR (c, stream, '\'');
  91   fputc_filtered ('\'', stream);
  92 }
  93
  94 /* Print the character string STRING, printing at most LENGTH characters.
  95    LENGTH is -1 if the string is nul terminated.  Each character is WIDTH bytes
  96    long.  Printing stops early if the number hits print_max; repeat counts are
  97    printed as appropriate.  Print ellipses at the end if we had to stop before
  98    printing LENGTH characters, or if FORCE_ELLIPSES.  */
  99
 100 void
 101 c_printstr (stream, string, length, width, force_ellipses)
 102      GDB_FILE *stream;
 103      char *string;
 104      unsigned int length;
 105      int width;
 106      int force_ellipses;
 107 {
 108   register unsigned int i;
 109   unsigned int things_printed = 0;
 110   int in_quotes = 0;
 111   int need_comma = 0;
 112   extern int inspect_it;
 113   extern int repeat_count_threshold;
 114   extern int print_max;
 115
 116   /* If the string was not truncated due to `set print elements', and
 117      the last byte of it is a null, we don't print that, in traditional C
 118      style.  */
 119   if (!force_ellipses
 120       && length > 0
 121   && extract_unsigned_integer (string + (length - 1) * width, width) == '\0')
 122     length--;
 123
 124   if (length == 0)
 125     {
 126       fputs_filtered ("\"\"", stream);
 127       return;
 128     }
 129
 130   for (i = 0; i < length && things_printed < print_max; ++i)
 131     {
 132       /* Position of the character we are examining
 133          to see whether it is repeated.  */
 134       unsigned int rep1;
 135       /* Number of repetitions we have detected so far.  */
 136       unsigned int reps;
 137       unsigned long current_char;
 138
 139       QUIT;
 140
 141       if (need_comma)
 142         {
 143           fputs_filtered (", ", stream);
 144           need_comma = 0;
 145         }
 146
 147       current_char = extract_unsigned_integer (string + i * width, width);
 148
 149       rep1 = i + 1;
 150       reps = 1;
 151       while (rep1 < length
 152              && extract_unsigned_integer (string + rep1 * width, width)
 153              == current_char)
 154         {
 155           ++rep1;
 156           ++reps;
 157         }
 158
 159       if (reps > repeat_count_threshold)
 160         {
 161           if (in_quotes)
 162             {
 163               if (inspect_it)
 164                 fputs_filtered ("\\\", ", stream);
 165               else
 166                 fputs_filtered ("\", ", stream);
 167               in_quotes = 0;
 168             }
 169           LA_PRINT_CHAR (current_char, stream);
 170           fprintf_filtered (stream, " <repeats %u times>", reps);
 171           i = rep1 - 1;
 172           things_printed += repeat_count_threshold;
 173           need_comma = 1;
 174         }
 175       else
 176         {
 177           if (!in_quotes)
 178             {
 179               if (inspect_it)
 180                 fputs_filtered ("\\\"", stream);
 181               else
 182                 fputs_filtered ("\"", stream);
 183               in_quotes = 1;
 184             }
 185           LA_EMIT_CHAR (current_char, stream, '"');
 186           ++things_printed;
 187         }
 188     }
 189
 190   /* Terminate the quotes if necessary.  */
 191   if (in_quotes)
 192     {
 193       if (inspect_it)
 194         fputs_filtered ("\\\"", stream);
 195       else
 196         fputs_filtered ("\"", stream);
 197     }
 198
 199   if (force_ellipses || i < length)
 200     fputs_filtered ("...", stream);
 201 }
 202
 203 /* Create a fundamental C type using default reasonable for the current
 204    target machine.
 205
 206    Some object/debugging file formats (DWARF version 1, COFF, etc) do not
 207    define fundamental types such as "int" or "double".  Others (stabs or
 208    DWARF version 2, etc) do define fundamental types.  For the formats which
 209    don't provide fundamental types, gdb can create such types using this
 210    function.
 211
 212    FIXME:  Some compilers distinguish explicitly signed integral types
 213    (signed short, signed int, signed long) from "regular" integral types
 214    (short, int, long) in the debugging information.  There is some dis-
 215    agreement as to how useful this feature is.  In particular, gcc does
 216    not support this.  Also, only some debugging formats allow the
 217    distinction to be passed on to a debugger.  For now, we always just
 218    use "short", "int", or "long" as the type name, for both the implicit
 219    and explicitly signed types.  This also makes life easier for the
 220    gdb test suite since we don't have to account for the differences
 221    in output depending upon what the compiler and debugging format
 222    support.  We will probably have to re-examine the issue when gdb
 223    starts taking it's fundamental type information directly from the
 224    debugging information supplied by the compiler.  fnf@cygnus.com */
 225
 226 struct type *
 227 c_create_fundamental_type (objfile, typeid)
 228      struct objfile *objfile;
 229      int typeid;
 230 {
 231   register struct type *type = NULL;
 232
 233   switch (typeid)
 234     {
 235     default:
 236       /* FIXME:  For now, if we are asked to produce a type not in this
 237          language, create the equivalent of a C integer type with the
 238          name "<?type?>".  When all the dust settles from the type
 239          reconstruction work, this should probably become an error. */
 240       type = init_type (TYPE_CODE_INT,
 241                         TARGET_INT_BIT / TARGET_CHAR_BIT,
 242                         0, "<?type?>", objfile);
 243       warning ("internal error: no C/C++ fundamental type %d", typeid);
 244       break;
 245     case FT_VOID:
 246       type = init_type (TYPE_CODE_VOID,
 247                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 248                         0, "void", objfile);
 249       break;
 250     case FT_BOOLEAN:
 251       type = init_type (TYPE_CODE_BOOL,
 252                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 253                         0, "bool", objfile);
 254
 255       break;
 256     case FT_CHAR:
 257       type = init_type (TYPE_CODE_INT,
 258                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 259                         0, "char", objfile);
 260       TYPE_FLAGS (type) |= TYPE_FLAG_NOSIGN;
 261       break;
 262     case FT_SIGNED_CHAR:
 263       type = init_type (TYPE_CODE_INT,
 264                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 265                         0, "signed char", objfile);
 266       break;
 267     case FT_UNSIGNED_CHAR:
 268       type = init_type (TYPE_CODE_INT,
 269                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 270                         TYPE_FLAG_UNSIGNED, "unsigned char", objfile);
 271       break;
 272     case FT_SHORT:
 273       type = init_type (TYPE_CODE_INT,
 274                         TARGET_SHORT_BIT / TARGET_CHAR_BIT,
 275                         0, "short", objfile);
 276       break;
 277     case FT_SIGNED_SHORT:
 278       type = init_type (TYPE_CODE_INT,
 279                         TARGET_SHORT_BIT / TARGET_CHAR_BIT,
 280                         0, "short", objfile);   /* FIXME-fnf */
 281       break;
 282     case FT_UNSIGNED_SHORT:
 283       type = init_type (TYPE_CODE_INT,
 284                         TARGET_SHORT_BIT / TARGET_CHAR_BIT,
 285                         TYPE_FLAG_UNSIGNED, "unsigned short", objfile);
 286       break;
 287     case FT_INTEGER:
 288       type = init_type (TYPE_CODE_INT,
 289                         TARGET_INT_BIT / TARGET_CHAR_BIT,
 290                         0, "int", objfile);
 291       break;
 292     case FT_SIGNED_INTEGER:
 293       type = init_type (TYPE_CODE_INT,
 294                         TARGET_INT_BIT / TARGET_CHAR_BIT,
 295                         0, "int", objfile);     /* FIXME -fnf */
 296       break;
 297     case FT_UNSIGNED_INTEGER:
 298       type = init_type (TYPE_CODE_INT,
 299                         TARGET_INT_BIT / TARGET_CHAR_BIT,
 300                         TYPE_FLAG_UNSIGNED, "unsigned int", objfile);
 301       break;
 302     case FT_LONG:
 303       type = init_type (TYPE_CODE_INT,
 304                         TARGET_LONG_BIT / TARGET_CHAR_BIT,
 305                         0, "long", objfile);
 306       break;
 307     case FT_SIGNED_LONG:
 308       type = init_type (TYPE_CODE_INT,
 309                         TARGET_LONG_BIT / TARGET_CHAR_BIT,
 310                         0, "long", objfile);    /* FIXME -fnf */
 311       break;
 312     case FT_UNSIGNED_LONG:
 313       type = init_type (TYPE_CODE_INT,
 314                         TARGET_LONG_BIT / TARGET_CHAR_BIT,
 315                         TYPE_FLAG_UNSIGNED, "unsigned long", objfile);
 316       break;
 317     case FT_LONG_LONG:
 318       type = init_type (TYPE_CODE_INT,
 319                         TARGET_LONG_LONG_BIT / TARGET_CHAR_BIT,
 320                         0, "long long", objfile);
 321       break;
 322     case FT_SIGNED_LONG_LONG:
 323       type = init_type (TYPE_CODE_INT,
 324                         TARGET_LONG_LONG_BIT / TARGET_CHAR_BIT,
 325                         0, "signed long long", objfile);
 326       break;
 327     case FT_UNSIGNED_LONG_LONG:
 328       type = init_type (TYPE_CODE_INT,
 329                         TARGET_LONG_LONG_BIT / TARGET_CHAR_BIT,
 330                         TYPE_FLAG_UNSIGNED, "unsigned long long", objfile);
 331       break;
 332     case FT_FLOAT:
 333       type = init_type (TYPE_CODE_FLT,
 334                         TARGET_FLOAT_BIT / TARGET_CHAR_BIT,
 335                         0, "float", objfile);
 336       break;
 337     case FT_DBL_PREC_FLOAT:
 338       type = init_type (TYPE_CODE_FLT,
 339                         TARGET_DOUBLE_BIT / TARGET_CHAR_BIT,
 340                         0, "double", objfile);
 341       break;
 342     case FT_EXT_PREC_FLOAT:
 343       type = init_type (TYPE_CODE_FLT,
 344                         TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT,
 345                         0, "long double", objfile);
 346       break;
 347     case FT_TEMPLATE_ARG:
 348       type = init_type (TYPE_CODE_TEMPLATE_ARG,
 349                         0,
 350                         0, "<template arg>", objfile);
 351
 352       break;
 353     }
 354   return (type);
 355 }
 356 \f
 357
 358 /* Table mapping opcodes into strings for printing operators
 359    and precedences of the operators.  */
 360
 361 const struct op_print c_op_print_tab[] =
 362 {
 363   {",", BINOP_COMMA, PREC_COMMA, 0},
 364   {"=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 365   {"||", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
 366   {"&&", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
 367   {"|", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 368   {"^", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 369   {"&", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 370   {"==", BINOP_EQUAL, PREC_EQUAL, 0},
 371   {"!=", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 372   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 373   {">=", BINOP_GEQ, PREC_ORDER, 0},
 374   {">", BINOP_GTR, PREC_ORDER, 0},
 375   {"<", BINOP_LESS, PREC_ORDER, 0},
 376   {">>", BINOP_RSH, PREC_SHIFT, 0},
 377   {"<<", BINOP_LSH, PREC_SHIFT, 0},
 378   {"+", BINOP_ADD, PREC_ADD, 0},
 379   {"-", BINOP_SUB, PREC_ADD, 0},
 380   {"*", BINOP_MUL, PREC_MUL, 0},
 381   {"/", BINOP_DIV, PREC_MUL, 0},
 382   {"%", BINOP_REM, PREC_MUL, 0},
 383   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 384   {"-", UNOP_NEG, PREC_PREFIX, 0},
 385   {"!", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 386   {"~", UNOP_COMPLEMENT, PREC_PREFIX, 0},
 387   {"*", UNOP_IND, PREC_PREFIX, 0},
 388   {"&", UNOP_ADDR, PREC_PREFIX, 0},
 389   {"sizeof ", UNOP_SIZEOF, PREC_PREFIX, 0},
 390   {"++", UNOP_PREINCREMENT, PREC_PREFIX, 0},
 391   {"--", UNOP_PREDECREMENT, PREC_PREFIX, 0},
 392     /* C++  */
 393   {"::", BINOP_SCOPE, PREC_PREFIX, 0},
 394   {NULL, 0, 0, 0}
 395 };
 396 \f
 397 struct type **CONST_PTR (c_builtin_types[]) =
 398 {
 399   &builtin_type_int,
 400     &builtin_type_long,
 401     &builtin_type_short,
 402     &builtin_type_char,
 403     &builtin_type_float,
 404     &builtin_type_double,
 405     &builtin_type_void,
 406     &builtin_type_long_long,
 407     &builtin_type_signed_char,
 408     &builtin_type_unsigned_char,
 409     &builtin_type_unsigned_short,
 410     &builtin_type_unsigned_int,
 411     &builtin_type_unsigned_long,
 412     &builtin_type_unsigned_long_long,
 413     &builtin_type_long_double,
 414     &builtin_type_complex,
 415     &builtin_type_double_complex,
 416     0
 417 };
 418
 419 const struct language_defn c_language_defn =
 420 {
 421   "c",                          /* Language name */
 422   language_c,
 423   c_builtin_types,
 424   range_check_off,
 425   type_check_off,
 426   c_parse,
 427   c_error,
 428   evaluate_subexp_standard,
 429   c_printchar,                  /* Print a character constant */
 430   c_printstr,                   /* Function to print string constant */
 431   c_emit_char,                  /* Print a single char */
 432   c_create_fundamental_type,    /* Create fundamental type in this language */
 433   c_print_type,                 /* Print a type using appropriate syntax */
 434   c_val_print,                  /* Print a value using appropriate syntax */
 435   c_value_print,                /* Print a top-level value */
 436   {"", "", "", ""},             /* Binary format info */
 437   {"0%lo", "0", "o", ""},       /* Octal format info */
 438   {"%ld", "", "d", ""},         /* Decimal format info */
 439   {"0x%lx", "0x", "x", ""},     /* Hex format info */
 440   c_op_print_tab,               /* expression operators for printing */
 441   1,                            /* c-style arrays */
 442   0,                            /* String lower bound */
 443   &builtin_type_char,           /* Type of string elements */
 444   LANG_MAGIC
 445 };
 446
 447 struct type **const (cplus_builtin_types[]) =
 448 {
 449   &builtin_type_int,
 450     &builtin_type_long,
 451     &builtin_type_short,
 452     &builtin_type_char,
 453     &builtin_type_float,
 454     &builtin_type_double,
 455     &builtin_type_void,
 456     &builtin_type_long_long,
 457     &builtin_type_signed_char,
 458     &builtin_type_unsigned_char,
 459     &builtin_type_unsigned_short,
 460     &builtin_type_unsigned_int,
 461     &builtin_type_unsigned_long,
 462     &builtin_type_unsigned_long_long,
 463     &builtin_type_long_double,
 464     &builtin_type_complex,
 465     &builtin_type_double_complex,
 466     &builtin_type_bool,
 467     0
 468 };
 469
 470 const struct language_defn cplus_language_defn =
 471 {
 472   "c++",                        /* Language name */
 473   language_cplus,
 474   cplus_builtin_types,
 475   range_check_off,
 476   type_check_off,
 477   c_parse,
 478   c_error,
 479   evaluate_subexp_standard,
 480   c_printchar,                  /* Print a character constant */
 481   c_printstr,                   /* Function to print string constant */
 482   c_emit_char,                  /* Print a single char */
 483   c_create_fundamental_type,    /* Create fundamental type in this language */
 484   c_print_type,                 /* Print a type using appropriate syntax */
 485   c_val_print,                  /* Print a value using appropriate syntax */
 486   c_value_print,                /* Print a top-level value */
 487   {"", "", "", ""},             /* Binary format info */
 488   {"0%lo", "0", "o", ""},       /* Octal format info */
 489   {"%ld", "", "d", ""},         /* Decimal format info */
 490   {"0x%lx", "0x", "x", ""},     /* Hex format info */
 491   c_op_print_tab,               /* expression operators for printing */
 492   1,                            /* c-style arrays */
 493   0,                            /* String lower bound */
 494   &builtin_type_char,           /* Type of string elements */
 495   LANG_MAGIC
 496 };
 497
 498 const struct language_defn asm_language_defn =
 499 {
 500   "asm",                        /* Language name */
 501   language_asm,
 502   c_builtin_types,
 503   range_check_off,
 504   type_check_off,
 505   c_parse,
 506   c_error,
 507   evaluate_subexp_standard,
 508   c_printchar,                  /* Print a character constant */
 509   c_printstr,                   /* Function to print string constant */
 510   c_emit_char,                  /* Print a single char */
 511   c_create_fundamental_type,    /* Create fundamental type in this language */
 512   c_print_type,                 /* Print a type using appropriate syntax */
 513   c_val_print,                  /* Print a value using appropriate syntax */
 514   c_value_print,                /* Print a top-level value */
 515   {"", "", "", ""},             /* Binary format info */
 516   {"0%lo", "0", "o", ""},       /* Octal format info */
 517   {"%ld", "", "d", ""},         /* Decimal format info */
 518   {"0x%lx", "0x", "x", ""},     /* Hex format info */
 519   c_op_print_tab,               /* expression operators for printing */
 520   1,                            /* c-style arrays */
 521   0,                            /* String lower bound */
 522   &builtin_type_char,           /* Type of string elements */
 523   LANG_MAGIC
 524 };
 525
 526 void
 527 _initialize_c_language ()
 528 {
 529   add_language (&c_language_defn);
 530   add_language (&cplus_language_defn);
 531   add_language (&asm_language_defn);
 532 }