gdb/c-lang.c

   1 /* C language support routines for GDB, the GNU debugger.
   2    Copyright 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2002
   3    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 2 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, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  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 "c-lang.h"
  29 #include "valprint.h"
  30
  31 extern void _initialize_c_language (void);
  32 static void c_emit_char (int c, struct ui_file * stream, int quoter);
  33
  34 /* Print the character C on STREAM as part of the contents of a literal
  35    string whose delimiter is QUOTER.  Note that that format for printing
  36    characters and strings is language specific. */
  37
  38 static void
  39 c_emit_char (register int c, struct ui_file *stream, int quoter)
  40 {
  41   c &= 0xFF;                    /* Avoid sign bit follies */
  42
  43   if (PRINT_LITERAL_FORM (c))
  44     {
  45       if (c == '\\' || c == quoter)
  46         {
  47           fputs_filtered ("\\", stream);
  48         }
  49       fprintf_filtered (stream, "%c", c);
  50     }
  51   else
  52     {
  53       switch (c)
  54         {
  55         case '\n':
  56           fputs_filtered ("\\n", stream);
  57           break;
  58         case '\b':
  59           fputs_filtered ("\\b", stream);
  60           break;
  61         case '\t':
  62           fputs_filtered ("\\t", stream);
  63           break;
  64         case '\f':
  65           fputs_filtered ("\\f", stream);
  66           break;
  67         case '\r':
  68           fputs_filtered ("\\r", stream);
  69           break;
  70         case '\013':
  71           fputs_filtered ("\\v", stream);
  72           break;
  73         case '\033':
  74           fputs_filtered ("\\e", stream);
  75           break;
  76         case '\007':
  77           fputs_filtered ("\\a", stream);
  78           break;
  79         case '\0':
  80           fputs_filtered ("\\0", stream);
  81           break;
  82         default:
  83           fprintf_filtered (stream, "\\%.3o", (unsigned int) c);
  84           break;
  85         }
  86     }
  87 }
  88
  89 void
  90 c_printchar (int c, struct ui_file *stream)
  91 {
  92   fputc_filtered ('\'', stream);
  93   LA_EMIT_CHAR (c, stream, '\'');
  94   fputc_filtered ('\'', stream);
  95 }
  96
  97 /* Print the character string STRING, printing at most LENGTH characters.
  98    LENGTH is -1 if the string is nul terminated.  Each character is WIDTH bytes
  99    long.  Printing stops early if the number hits print_max; repeat counts are
 100    printed as appropriate.  Print ellipses at the end if we had to stop before
 101    printing LENGTH characters, or if FORCE_ELLIPSES.  */
 102
 103 void
 104 c_printstr (struct ui_file *stream, char *string, unsigned int length,
 105             int width, int force_ellipses)
 106 {
 107   register unsigned int i;
 108   unsigned int things_printed = 0;
 109   int in_quotes = 0;
 110   int need_comma = 0;
 111   extern int inspect_it;
 112
 113   /* If the string was not truncated due to `set print elements', and
 114      the last byte of it is a null, we don't print that, in traditional C
 115      style.  */
 116   if (!force_ellipses
 117       && length > 0
 118       && (extract_unsigned_integer (string + (length - 1) * width, width)
 119           == '\0'))
 120     length--;
 121
 122   if (length == 0)
 123     {
 124       fputs_filtered ("\"\"", stream);
 125       return;
 126     }
 127
 128   for (i = 0; i < length && things_printed < print_max; ++i)
 129     {
 130       /* Position of the character we are examining
 131          to see whether it is repeated.  */
 132       unsigned int rep1;
 133       /* Number of repetitions we have detected so far.  */
 134       unsigned int reps;
 135       unsigned long current_char;
 136
 137       QUIT;
 138
 139       if (need_comma)
 140         {
 141           fputs_filtered (", ", stream);
 142           need_comma = 0;
 143         }
 144
 145       current_char = extract_unsigned_integer (string + i * width, width);
 146
 147       rep1 = i + 1;
 148       reps = 1;
 149       while (rep1 < length
 150              && extract_unsigned_integer (string + rep1 * width, width)
 151              == current_char)
 152         {
 153           ++rep1;
 154           ++reps;
 155         }
 156
 157       if (reps > repeat_count_threshold)
 158         {
 159           if (in_quotes)
 160             {
 161               if (inspect_it)
 162                 fputs_filtered ("\\\", ", stream);
 163               else
 164                 fputs_filtered ("\", ", stream);
 165               in_quotes = 0;
 166             }
 167           LA_PRINT_CHAR (current_char, stream);
 168           fprintf_filtered (stream, " <repeats %u times>", reps);
 169           i = rep1 - 1;
 170           things_printed += repeat_count_threshold;
 171           need_comma = 1;
 172         }
 173       else
 174         {
 175           if (!in_quotes)
 176             {
 177               if (inspect_it)
 178                 fputs_filtered ("\\\"", stream);
 179               else
 180                 fputs_filtered ("\"", stream);
 181               in_quotes = 1;
 182             }
 183           LA_EMIT_CHAR (current_char, stream, '"');
 184           ++things_printed;
 185         }
 186     }
 187
 188   /* Terminate the quotes if necessary.  */
 189   if (in_quotes)
 190     {
 191       if (inspect_it)
 192         fputs_filtered ("\\\"", stream);
 193       else
 194         fputs_filtered ("\"", stream);
 195     }
 196
 197   if (force_ellipses || i < length)
 198     fputs_filtered ("...", stream);
 199 }
 200
 201 /* Create a fundamental C type using default reasonable for the current
 202    target machine.
 203
 204    Some object/debugging file formats (DWARF version 1, COFF, etc) do not
 205    define fundamental types such as "int" or "double".  Others (stabs or
 206    DWARF version 2, etc) do define fundamental types.  For the formats which
 207    don't provide fundamental types, gdb can create such types using this
 208    function.
 209
 210    FIXME:  Some compilers distinguish explicitly signed integral types
 211    (signed short, signed int, signed long) from "regular" integral types
 212    (short, int, long) in the debugging information.  There is some dis-
 213    agreement as to how useful this feature is.  In particular, gcc does
 214    not support this.  Also, only some debugging formats allow the
 215    distinction to be passed on to a debugger.  For now, we always just
 216    use "short", "int", or "long" as the type name, for both the implicit
 217    and explicitly signed types.  This also makes life easier for the
 218    gdb test suite since we don't have to account for the differences
 219    in output depending upon what the compiler and debugging format
 220    support.  We will probably have to re-examine the issue when gdb
 221    starts taking it's fundamental type information directly from the
 222    debugging information supplied by the compiler.  fnf@cygnus.com */
 223
 224 struct type *
 225 c_create_fundamental_type (struct objfile *objfile, int typeid)
 226 {
 227   register struct type *type = NULL;
 228
 229   switch (typeid)
 230     {
 231     default:
 232       /* FIXME:  For now, if we are asked to produce a type not in this
 233          language, create the equivalent of a C integer type with the
 234          name "<?type?>".  When all the dust settles from the type
 235          reconstruction work, this should probably become an error. */
 236       type = init_type (TYPE_CODE_INT,
 237                         TARGET_INT_BIT / TARGET_CHAR_BIT,
 238                         0, "<?type?>", objfile);
 239       warning ("internal error: no C/C++ fundamental type %d", typeid);
 240       break;
 241     case FT_VOID:
 242       type = init_type (TYPE_CODE_VOID,
 243                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 244                         0, "void", objfile);
 245       break;
 246     case FT_BOOLEAN:
 247       type = init_type (TYPE_CODE_BOOL,
 248                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 249                         0, "bool", objfile);
 250       break;
 251     case FT_CHAR:
 252       type = init_type (TYPE_CODE_INT,
 253                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 254                         TYPE_FLAG_NOSIGN, "char", objfile);
 255       break;
 256     case FT_SIGNED_CHAR:
 257       type = init_type (TYPE_CODE_INT,
 258                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 259                         0, "signed char", objfile);
 260       break;
 261     case FT_UNSIGNED_CHAR:
 262       type = init_type (TYPE_CODE_INT,
 263                         TARGET_CHAR_BIT / TARGET_CHAR_BIT,
 264                         TYPE_FLAG_UNSIGNED, "unsigned char", objfile);
 265       break;
 266     case FT_SHORT:
 267       type = init_type (TYPE_CODE_INT,
 268                         TARGET_SHORT_BIT / TARGET_CHAR_BIT,
 269                         0, "short", objfile);
 270       break;
 271     case FT_SIGNED_SHORT:
 272       type = init_type (TYPE_CODE_INT,
 273                         TARGET_SHORT_BIT / TARGET_CHAR_BIT,
 274                         0, "short", objfile);   /* FIXME-fnf */
 275       break;
 276     case FT_UNSIGNED_SHORT:
 277       type = init_type (TYPE_CODE_INT,
 278                         TARGET_SHORT_BIT / TARGET_CHAR_BIT,
 279                         TYPE_FLAG_UNSIGNED, "unsigned short", objfile);
 280       break;
 281     case FT_INTEGER:
 282       type = init_type (TYPE_CODE_INT,
 283                         TARGET_INT_BIT / TARGET_CHAR_BIT,
 284                         0, "int", objfile);
 285       break;
 286     case FT_SIGNED_INTEGER:
 287       type = init_type (TYPE_CODE_INT,
 288                         TARGET_INT_BIT / TARGET_CHAR_BIT,
 289                         0, "int", objfile);     /* FIXME -fnf */
 290       break;
 291     case FT_UNSIGNED_INTEGER:
 292       type = init_type (TYPE_CODE_INT,
 293                         TARGET_INT_BIT / TARGET_CHAR_BIT,
 294                         TYPE_FLAG_UNSIGNED, "unsigned int", objfile);
 295       break;
 296     case FT_LONG:
 297       type = init_type (TYPE_CODE_INT,
 298                         TARGET_LONG_BIT / TARGET_CHAR_BIT,
 299                         0, "long", objfile);
 300       break;
 301     case FT_SIGNED_LONG:
 302       type = init_type (TYPE_CODE_INT,
 303                         TARGET_LONG_BIT / TARGET_CHAR_BIT,
 304                         0, "long", objfile);    /* FIXME -fnf */
 305       break;
 306     case FT_UNSIGNED_LONG:
 307       type = init_type (TYPE_CODE_INT,
 308                         TARGET_LONG_BIT / TARGET_CHAR_BIT,
 309                         TYPE_FLAG_UNSIGNED, "unsigned long", objfile);
 310       break;
 311     case FT_LONG_LONG:
 312       type = init_type (TYPE_CODE_INT,
 313                         TARGET_LONG_LONG_BIT / TARGET_CHAR_BIT,
 314                         0, "long long", objfile);
 315       break;
 316     case FT_SIGNED_LONG_LONG:
 317       type = init_type (TYPE_CODE_INT,
 318                         TARGET_LONG_LONG_BIT / TARGET_CHAR_BIT,
 319                         0, "signed long long", objfile);
 320       break;
 321     case FT_UNSIGNED_LONG_LONG:
 322       type = init_type (TYPE_CODE_INT,
 323                         TARGET_LONG_LONG_BIT / TARGET_CHAR_BIT,
 324                         TYPE_FLAG_UNSIGNED, "unsigned long long", objfile);
 325       break;
 326     case FT_FLOAT:
 327       type = init_type (TYPE_CODE_FLT,
 328                         TARGET_FLOAT_BIT / TARGET_CHAR_BIT,
 329                         0, "float", objfile);
 330       break;
 331     case FT_DBL_PREC_FLOAT:
 332       type = init_type (TYPE_CODE_FLT,
 333                         TARGET_DOUBLE_BIT / TARGET_CHAR_BIT,
 334                         0, "double", objfile);
 335       break;
 336     case FT_EXT_PREC_FLOAT:
 337       type = init_type (TYPE_CODE_FLT,
 338                         TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT,
 339                         0, "long double", objfile);
 340       break;
 341     case FT_TEMPLATE_ARG:
 342       type = init_type (TYPE_CODE_TEMPLATE_ARG,
 343                         0,
 344                         0, "<template arg>", objfile);
 345       break;
 346     }
 347   return (type);
 348 }
 349 \f
 350
 351 /* Table mapping opcodes into strings for printing operators
 352    and precedences of the operators.  */
 353
 354 const struct op_print c_op_print_tab[] =
 355 {
 356   {",", BINOP_COMMA, PREC_COMMA, 0},
 357   {"=", BINOP_ASSIGN, PREC_ASSIGN, 1},
 358   {"||", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
 359   {"&&", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
 360   {"|", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
 361   {"^", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
 362   {"&", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
 363   {"==", BINOP_EQUAL, PREC_EQUAL, 0},
 364   {"!=", BINOP_NOTEQUAL, PREC_EQUAL, 0},
 365   {"<=", BINOP_LEQ, PREC_ORDER, 0},
 366   {">=", BINOP_GEQ, PREC_ORDER, 0},
 367   {">", BINOP_GTR, PREC_ORDER, 0},
 368   {"<", BINOP_LESS, PREC_ORDER, 0},
 369   {">>", BINOP_RSH, PREC_SHIFT, 0},
 370   {"<<", BINOP_LSH, PREC_SHIFT, 0},
 371   {"+", BINOP_ADD, PREC_ADD, 0},
 372   {"-", BINOP_SUB, PREC_ADD, 0},
 373   {"*", BINOP_MUL, PREC_MUL, 0},
 374   {"/", BINOP_DIV, PREC_MUL, 0},
 375   {"%", BINOP_REM, PREC_MUL, 0},
 376   {"@", BINOP_REPEAT, PREC_REPEAT, 0},
 377   {"-", UNOP_NEG, PREC_PREFIX, 0},
 378   {"!", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
 379   {"~", UNOP_COMPLEMENT, PREC_PREFIX, 0},
 380   {"*", UNOP_IND, PREC_PREFIX, 0},
 381   {"&", UNOP_ADDR, PREC_PREFIX, 0},
 382   {"sizeof ", UNOP_SIZEOF, PREC_PREFIX, 0},
 383   {"++", UNOP_PREINCREMENT, PREC_PREFIX, 0},
 384   {"--", UNOP_PREDECREMENT, PREC_PREFIX, 0},
 385   {NULL, 0, 0, 0}
 386 };
 387 \f
 388 struct type **const (c_builtin_types[]) =
 389 {
 390   &builtin_type_int,
 391   &builtin_type_long,
 392   &builtin_type_short,
 393   &builtin_type_char,
 394   &builtin_type_float,
 395   &builtin_type_double,
 396   &builtin_type_void,
 397   &builtin_type_long_long,
 398   &builtin_type_signed_char,
 399   &builtin_type_unsigned_char,
 400   &builtin_type_unsigned_short,
 401   &builtin_type_unsigned_int,
 402   &builtin_type_unsigned_long,
 403   &builtin_type_unsigned_long_long,
 404   &builtin_type_long_double,
 405   &builtin_type_complex,
 406   &builtin_type_double_complex,
 407   0
 408 };
 409
 410 const struct language_defn c_language_defn =
 411 {
 412   "c",                          /* Language name */
 413   language_c,
 414   c_builtin_types,
 415   range_check_off,
 416   type_check_off,
 417   case_sensitive_on,
 418   c_parse,
 419   c_error,
 420   evaluate_subexp_standard,
 421   c_printchar,                  /* Print a character constant */
 422   c_printstr,                   /* Function to print string constant */
 423   c_emit_char,                  /* Print a single char */
 424   c_create_fundamental_type,    /* Create fundamental type in this language */
 425   c_print_type,                 /* Print a type using appropriate syntax */
 426   c_val_print,                  /* Print a value using appropriate syntax */
 427   c_value_print,                /* Print a top-level value */
 428   {"", "", "", ""},             /* Binary format info */
 429   {"0%lo", "0", "o", ""},       /* Octal format info */
 430   {"%ld", "", "d", ""},         /* Decimal format info */
 431   {"0x%lx", "0x", "x", ""},     /* Hex format info */
 432   c_op_print_tab,               /* expression operators for printing */
 433   1,                            /* c-style arrays */
 434   0,                            /* String lower bound */
 435   &builtin_type_char,           /* Type of string elements */
 436   LANG_MAGIC
 437 };
 438
 439 struct type **const (cplus_builtin_types[]) =
 440 {
 441   &builtin_type_int,
 442   &builtin_type_long,
 443   &builtin_type_short,
 444   &builtin_type_char,
 445   &builtin_type_float,
 446   &builtin_type_double,
 447   &builtin_type_void,
 448   &builtin_type_long_long,
 449   &builtin_type_signed_char,
 450   &builtin_type_unsigned_char,
 451   &builtin_type_unsigned_short,
 452   &builtin_type_unsigned_int,
 453   &builtin_type_unsigned_long,
 454   &builtin_type_unsigned_long_long,
 455   &builtin_type_long_double,
 456   &builtin_type_complex,
 457   &builtin_type_double_complex,
 458   &builtin_type_bool,
 459   0
 460 };
 461
 462 const struct language_defn cplus_language_defn =
 463 {
 464   "c++",                        /* Language name */
 465   language_cplus,
 466   cplus_builtin_types,
 467   range_check_off,
 468   type_check_off,
 469   case_sensitive_on,
 470   c_parse,
 471   c_error,
 472   evaluate_subexp_standard,
 473   c_printchar,                  /* Print a character constant */
 474   c_printstr,                   /* Function to print string constant */
 475   c_emit_char,                  /* Print a single char */
 476   c_create_fundamental_type,    /* Create fundamental type in this language */
 477   c_print_type,                 /* Print a type using appropriate syntax */
 478   c_val_print,                  /* Print a value using appropriate syntax */
 479   c_value_print,                /* Print a top-level value */
 480   {"", "", "", ""},             /* Binary format info */
 481   {"0%lo", "0", "o", ""},       /* Octal format info */
 482   {"%ld", "", "d", ""},         /* Decimal format info */
 483   {"0x%lx", "0x", "x", ""},     /* Hex format info */
 484   c_op_print_tab,               /* expression operators for printing */
 485   1,                            /* c-style arrays */
 486   0,                            /* String lower bound */
 487   &builtin_type_char,           /* Type of string elements */
 488   LANG_MAGIC
 489 };
 490
 491 const struct language_defn asm_language_defn =
 492 {
 493   "asm",                        /* Language name */
 494   language_asm,
 495   c_builtin_types,
 496   range_check_off,
 497   type_check_off,
 498   case_sensitive_on,
 499   c_parse,
 500   c_error,
 501   evaluate_subexp_standard,
 502   c_printchar,                  /* Print a character constant */
 503   c_printstr,                   /* Function to print string constant */
 504   c_emit_char,                  /* Print a single char */
 505   c_create_fundamental_type,    /* Create fundamental type in this language */
 506   c_print_type,                 /* Print a type using appropriate syntax */
 507   c_val_print,                  /* Print a value using appropriate syntax */
 508   c_value_print,                /* Print a top-level value */
 509   {"", "", "", ""},             /* Binary format info */
 510   {"0%lo", "0", "o", ""},       /* Octal format info */
 511   {"%ld", "", "d", ""},         /* Decimal format info */
 512   {"0x%lx", "0x", "x", ""},     /* Hex format info */
 513   c_op_print_tab,               /* expression operators for printing */
 514   1,                            /* c-style arrays */
 515   0,                            /* String lower bound */
 516   &builtin_type_char,           /* Type of string elements */
 517   LANG_MAGIC
 518 };
 519
 520 void
 521 _initialize_c_language (void)
 522 {
 523   add_language (&c_language_defn);
 524   add_language (&cplus_language_defn);
 525   add_language (&asm_language_defn);
 526 }