gdb/language.h

   1 /* Source-language-related definitions for GDB.
   2
   3    Copyright (C) 1991-1995, 1998-2000, 2003-2004, 2007-2012 Free
   4    Software Foundation, Inc.
   5
   6    Contributed by the Department of Computer Science at the State University
   7    of New York at Buffalo.
   8
   9    This file is part of GDB.
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  23
  24 #if !defined (LANGUAGE_H)
  25 #define LANGUAGE_H 1
  26
  27 /* Forward decls for prototypes.  */
  28 struct value;
  29 struct objfile;
  30 struct frame_info;
  31 struct expression;
  32 struct ui_file;
  33 struct value_print_options;
  34
  35 #define MAX_FORTRAN_DIMS  7     /* Maximum number of F77 array dims.  */
  36
  37 /* range_mode ==
  38    range_mode_auto:   range_check set automatically to default of language.
  39    range_mode_manual: range_check set manually by user.  */
  40
  41 extern enum range_mode
  42   {
  43     range_mode_auto, range_mode_manual
  44   }
  45 range_mode;
  46
  47 /* range_check ==
  48    range_check_on:    Ranges are checked in GDB expressions, producing errors.
  49    range_check_warn:  Ranges are checked, producing warnings.
  50    range_check_off:   Ranges are not checked in GDB expressions.  */
  51
  52 extern enum range_check
  53   {
  54     range_check_off, range_check_warn, range_check_on
  55   }
  56 range_check;
  57
  58 /* type_mode ==
  59    type_mode_auto:   type_check set automatically to default of language.
  60    type_mode_manual: type_check set manually by user.  */
  61
  62 extern enum type_mode
  63   {
  64     type_mode_auto, type_mode_manual
  65   }
  66 type_mode;
  67
  68 /* type_check ==
  69    type_check_on:    Types are checked in GDB expressions, producing errors.
  70    type_check_warn:  Types are checked, producing warnings.
  71    type_check_off:   Types are not checked in GDB expressions.  */
  72
  73 extern enum type_check
  74   {
  75     type_check_off, type_check_warn, type_check_on
  76   }
  77 type_check;
  78
  79 /* case_mode ==
  80    case_mode_auto:   case_sensitivity set upon selection of scope.
  81    case_mode_manual: case_sensitivity set only by user.  */
  82
  83 extern enum case_mode
  84   {
  85     case_mode_auto, case_mode_manual
  86   }
  87 case_mode;
  88
  89 /* array_ordering ==
  90    array_row_major:     Arrays are in row major order.
  91    array_column_major:  Arrays are in column major order.  */
  92
  93 extern enum array_ordering
  94   {
  95     array_row_major, array_column_major
  96   }
  97 array_ordering;
  98
  99
 100 /* case_sensitivity ==
 101    case_sensitive_on:   Case sensitivity in name matching is used.
 102    case_sensitive_off:  Case sensitivity in name matching is not used.  */
 103
 104 extern enum case_sensitivity
 105   {
 106     case_sensitive_on, case_sensitive_off
 107   }
 108 case_sensitivity;
 109
 110
 111 /* macro_expansion ==
 112    macro_expansion_no:  No macro expansion is available.
 113    macro_expansion_c:   C-like macro expansion is available.  */
 114
 115 enum macro_expansion
 116   {
 117     macro_expansion_no, macro_expansion_c
 118   };
 119
 120 \f
 121 /* Per architecture (OS/ABI) language information.  */
 122
 123 struct language_arch_info
 124 {
 125   /* Its primitive types.  This is a vector ended by a NULL pointer.
 126      These types can be specified by name in parsing types in
 127      expressions, regardless of whether the program being debugged
 128      actually defines such a type.  */
 129   struct type **primitive_type_vector;
 130   /* Type of elements of strings.  */
 131   struct type *string_char_type;
 132
 133   /* Symbol name of type to use as boolean type, if defined.  */
 134   const char *bool_type_symbol;
 135   /* Otherwise, this is the default boolean builtin type.  */
 136   struct type *bool_type_default;
 137 };
 138
 139 /* A pointer to a function expected to return nonzero if
 140    SYMBOL_SEARCH_NAME matches the given LOOKUP_NAME.
 141
 142    SYMBOL_SEARCH_NAME should be a symbol's "search" name.
 143    LOOKUP_NAME should be the name of an entity after it has been
 144    transformed for lookup.  */
 145
 146 typedef int (*symbol_name_cmp_ftype) (const char *symbol_search_name,
 147                                           const char *lookup_name);
 148
 149 /* Structure tying together assorted information about a language.  */
 150
 151 struct language_defn
 152   {
 153     /* Name of the language.  */
 154
 155     char *la_name;
 156
 157     /* its symtab language-enum (defs.h).  */
 158
 159     enum language la_language;
 160
 161     /* Default range checking.  */
 162
 163     enum range_check la_range_check;
 164
 165     /* Default type checking.  */
 166
 167     enum type_check la_type_check;
 168
 169     /* Default case sensitivity.  */
 170     enum case_sensitivity la_case_sensitivity;
 171
 172     /* Multi-dimensional array ordering.  */
 173     enum array_ordering la_array_ordering;
 174
 175     /* Style of macro expansion, if any, supported by this language.  */
 176     enum macro_expansion la_macro_expansion;
 177
 178     /* Definitions related to expression printing, prefixifying, and
 179        dumping.  */
 180
 181     const struct exp_descriptor *la_exp_desc;
 182
 183     /* Parser function.  */
 184
 185     int (*la_parser) (void);
 186
 187     /* Parser error function.  */
 188
 189     void (*la_error) (char *);
 190
 191     /* Given an expression *EXPP created by prefixifying the result of
 192        la_parser, perform any remaining processing necessary to complete
 193        its translation.  *EXPP may change; la_post_parser is responsible
 194        for releasing its previous contents, if necessary.  If
 195        VOID_CONTEXT_P, then no value is expected from the expression.  */
 196
 197     void (*la_post_parser) (struct expression ** expp, int void_context_p);
 198
 199     void (*la_printchar) (int ch, struct type *chtype,
 200                           struct ui_file * stream);
 201
 202     void (*la_printstr) (struct ui_file * stream, struct type *elttype,
 203                          const gdb_byte *string, unsigned int length,
 204                          const char *encoding, int force_ellipses,
 205                          const struct value_print_options *);
 206
 207     void (*la_emitchar) (int ch, struct type *chtype,
 208                          struct ui_file * stream, int quoter);
 209
 210     /* Print a type using syntax appropriate for this language.  */
 211
 212     void (*la_print_type) (struct type *, const char *, struct ui_file *, int,
 213                            int);
 214
 215     /* Print a typedef using syntax appropriate for this language.
 216        TYPE is the underlying type.  NEW_SYMBOL is the symbol naming
 217        the type.  STREAM is the output stream on which to print.  */
 218
 219     void (*la_print_typedef) (struct type *type, struct symbol *new_symbol,
 220                               struct ui_file *stream);
 221
 222     /* Print a value using syntax appropriate for this language.
 223
 224        TYPE is the type of the sub-object to be printed.
 225
 226        CONTENTS holds the bits of the value.  This holds the entire
 227        enclosing object.
 228
 229        EMBEDDED_OFFSET is the offset into the outermost object of the
 230        sub-object represented by TYPE.  This is the object which this
 231        call should print.  Note that the enclosing type is not
 232        available.
 233
 234        ADDRESS is the address in the inferior of the enclosing object.
 235
 236        STREAM is the stream on which the value is to be printed.
 237
 238        RECURSE is the recursion depth.  It is zero-based.
 239
 240        OPTIONS are the formatting options to be used when
 241        printing.  */
 242
 243     void (*la_val_print) (struct type *type,
 244                           const gdb_byte *contents,
 245                           int embedded_offset, CORE_ADDR address,
 246                           struct ui_file *stream, int recurse,
 247                           const struct value *val,
 248                           const struct value_print_options *options);
 249
 250     /* Print a top-level value using syntax appropriate for this language.  */
 251
 252     void (*la_value_print) (struct value *, struct ui_file *,
 253                             const struct value_print_options *);
 254
 255     /* Given a symbol VAR, and a stack frame id FRAME, read the value
 256        of the variable an return (pointer to a) struct value containing
 257        the value.
 258
 259        Throw an error if the variable cannot be found.  */
 260
 261     struct value *(*la_read_var_value) (struct symbol *var,
 262                                         struct frame_info *frame);
 263
 264     /* PC is possibly an unknown languages trampoline.
 265        If that PC falls in a trampoline belonging to this language,
 266        return the address of the first pc in the real function, or 0
 267        if it isn't a language tramp for this language.  */
 268     CORE_ADDR (*skip_trampoline) (struct frame_info *, CORE_ADDR);
 269
 270     /* Now come some hooks for lookup_symbol.  */
 271
 272     /* If this is non-NULL, specifies the name that of the implicit
 273        local variable that refers to the current object instance.  */
 274
 275     char *la_name_of_this;
 276
 277     /* This is a function that lookup_symbol will call when it gets to
 278        the part of symbol lookup where C looks up static and global
 279        variables.  */
 280
 281     struct symbol *(*la_lookup_symbol_nonlocal) (const char *,
 282                                                  const struct block *,
 283                                                  const domain_enum);
 284
 285     /* Find the definition of the type with the given name.  */
 286     struct type *(*la_lookup_transparent_type) (const char *);
 287
 288     /* Return demangled language symbol, or NULL.  */
 289     char *(*la_demangle) (const char *mangled, int options);
 290
 291     /* Return class name of a mangled method name or NULL.  */
 292     char *(*la_class_name_from_physname) (const char *physname);
 293
 294     /* Table for printing expressions.  */
 295
 296     const struct op_print *la_op_print_tab;
 297
 298     /* Zero if the language has first-class arrays.  True if there are no
 299        array values, and array objects decay to pointers, as in C.  */
 300
 301     char c_style_arrays;
 302
 303     /* Index to use for extracting the first element of a string.  */
 304     char string_lower_bound;
 305
 306     /* The list of characters forming word boundaries.  */
 307     char *(*la_word_break_characters) (void);
 308
 309     /* Should return a NULL terminated array of all symbols which
 310        are possible completions for TEXT.  WORD is the entire command
 311        on which the completion is being made.  */
 312     char **(*la_make_symbol_completion_list) (char *text, char *word);
 313
 314     /* The per-architecture (OS/ABI) language information.  */
 315     void (*la_language_arch_info) (struct gdbarch *,
 316                                    struct language_arch_info *);
 317
 318     /* Print the index of an element of an array.  */
 319     void (*la_print_array_index) (struct value *index_value,
 320                                   struct ui_file *stream,
 321                                   const struct value_print_options *options);
 322
 323     /* Return non-zero if TYPE should be passed (and returned) by
 324        reference at the language level.  */
 325     int (*la_pass_by_reference) (struct type *type);
 326
 327     /* Obtain a string from the inferior, storing it in a newly allocated
 328        buffer in BUFFER, which should be freed by the caller.  If the
 329        in- and out-parameter *LENGTH is specified at -1, the string is
 330        read until a null character of the appropriate width is found -
 331        otherwise the string is read to the length of characters specified.
 332        On completion, *LENGTH will hold the size of the string in characters.
 333        If a *LENGTH of -1 was specified it will count only actual
 334        characters, excluding any eventual terminating null character.
 335        Otherwise *LENGTH will include all characters - including any nulls.
 336        CHARSET will hold the encoding used in the string.  */
 337     void (*la_get_string) (struct value *value, gdb_byte **buffer, int *length,
 338                            struct type **chartype, const char **charset);
 339
 340     /* Return a pointer to the function that should be used to match
 341        a symbol name against LOOKUP_NAME. This is mostly for languages
 342        such as Ada where the matching algorithm depends on LOOKUP_NAME.
 343
 344        This field may be NULL, in which case strcmp_iw will be used
 345        to perform the matching.  */
 346     symbol_name_cmp_ftype (*la_get_symbol_name_cmp) (const char *lookup_name);
 347
 348     /* Find all symbols in the current program space matching NAME in
 349        DOMAIN, according to this language's rules.
 350
 351        The search starts with BLOCK.  This function iterates upward
 352        through blocks.  When the outermost block has been finished,
 353        the function returns.
 354
 355        For each one, call CALLBACK with the symbol and the DATA
 356        argument.  If CALLBACK returns zero, the iteration ends at that
 357        point.
 358
 359        This field may not be NULL.  If the language does not need any
 360        special processing here, 'iterate_over_symbols' should be
 361        used as the definition.  */
 362     void (*la_iterate_over_symbols) (const struct block *block,
 363                                      const char *name,
 364                                      domain_enum domain,
 365                                      symbol_found_callback_ftype *callback,
 366                                      void *data);
 367
 368     /* Add fields above this point, so the magic number is always last.  */
 369     /* Magic number for compat checking.  */
 370
 371     long la_magic;
 372
 373   };
 374
 375 #define LANG_MAGIC      910823L
 376
 377 /* Pointer to the language_defn for our current language.  This pointer
 378    always points to *some* valid struct; it can be used without checking
 379    it for validity.
 380
 381    The current language affects expression parsing and evaluation
 382    (FIXME: it might be cleaner to make the evaluation-related stuff
 383    separate exp_opcodes for each different set of semantics.  We
 384    should at least think this through more clearly with respect to
 385    what happens if the language is changed between parsing and
 386    evaluation) and printing of things like types and arrays.  It does
 387    *not* affect symbol-reading-- each source file in a symbol-file has
 388    its own language and we should keep track of that regardless of the
 389    language when symbols are read.  If we want some manual setting for
 390    the language of symbol files (e.g. detecting when ".c" files are
 391    C++), it should be a separate setting from the current_language.  */
 392
 393 extern const struct language_defn *current_language;
 394
 395 /* Pointer to the language_defn expected by the user, e.g. the language
 396    of main(), or the language we last mentioned in a message, or C.  */
 397
 398 extern const struct language_defn *expected_language;
 399
 400 /* language_mode ==
 401    language_mode_auto:   current_language automatically set upon selection
 402    of scope (e.g. stack frame)
 403    language_mode_manual: current_language set only by user.  */
 404
 405 extern enum language_mode
 406   {
 407     language_mode_auto, language_mode_manual
 408   }
 409 language_mode;
 410
 411 struct type *language_bool_type (const struct language_defn *l,
 412                                  struct gdbarch *gdbarch);
 413
 414 struct type *language_string_char_type (const struct language_defn *l,
 415                                         struct gdbarch *gdbarch);
 416
 417 struct type *language_lookup_primitive_type_by_name (const struct language_defn *l,
 418                                                      struct gdbarch *gdbarch,
 419                                                      const char *name);
 420
 421 \f
 422 /* These macros define the behaviour of the expression
 423    evaluator.  */
 424
 425 /* Should we strictly type check expressions?  */
 426 #define STRICT_TYPE (type_check != type_check_off)
 427
 428 /* Should we range check values against the domain of their type?  */
 429 #define RANGE_CHECK (range_check != range_check_off)
 430
 431 /* "cast" really means conversion.  */
 432 /* FIXME -- should be a setting in language_defn.  */
 433 #define CAST_IS_CONVERSION(LANG) ((LANG)->la_language == language_c  || \
 434                                   (LANG)->la_language == language_cplus || \
 435                                   (LANG)->la_language == language_objc)
 436
 437 extern void language_info (int);
 438
 439 extern enum language set_language (enum language);
 440 \f
 441
 442 /* This page contains functions that return things that are
 443    specific to languages.  Each of these functions is based on
 444    the current setting of working_lang, which the user sets
 445    with the "set language" command.  */
 446
 447 #define LA_PRINT_TYPE(type,varstring,stream,show,level) \
 448   (current_language->la_print_type(type,varstring,stream,show,level))
 449
 450 #define LA_PRINT_TYPEDEF(type,new_symbol,stream) \
 451   (current_language->la_print_typedef(type,new_symbol,stream))
 452
 453 #define LA_VAL_PRINT(type,valaddr,offset,addr,stream,val,recurse,options) \
 454   (current_language->la_val_print(type,valaddr,offset,addr,stream, \
 455                                   val,recurse,options))
 456 #define LA_VALUE_PRINT(val,stream,options) \
 457   (current_language->la_value_print(val,stream,options))
 458
 459 #define LA_PRINT_CHAR(ch, type, stream) \
 460   (current_language->la_printchar(ch, type, stream))
 461 #define LA_PRINT_STRING(stream, elttype, string, length, encoding, force_ellipses, options) \
 462   (current_language->la_printstr(stream, elttype, string, length, \
 463                                  encoding, force_ellipses,options))
 464 #define LA_EMIT_CHAR(ch, type, stream, quoter) \
 465   (current_language->la_emitchar(ch, type, stream, quoter))
 466 #define LA_GET_STRING(value, buffer, length, chartype, encoding) \
 467   (current_language->la_get_string(value, buffer, length, chartype, encoding))
 468
 469 #define LA_PRINT_ARRAY_INDEX(index_value, stream, options) \
 470   (current_language->la_print_array_index(index_value, stream, options))
 471
 472 #define LA_ITERATE_OVER_SYMBOLS(BLOCK, NAME, DOMAIN, CALLBACK, DATA) \
 473   (current_language->la_iterate_over_symbols (BLOCK, NAME, DOMAIN, CALLBACK, \
 474                                               DATA))
 475
 476 /* Test a character to decide whether it can be printed in literal form
 477    or needs to be printed in another representation.  For example,
 478    in C the literal form of the character with octal value 141 is 'a'
 479    and the "other representation" is '\141'.  The "other representation"
 480    is program language dependent.  */
 481
 482 #define PRINT_LITERAL_FORM(c)           \
 483   ((c) >= 0x20                          \
 484    && ((c) < 0x7F || (c) >= 0xA0)       \
 485    && (!sevenbit_strings || (c) < 0x80))
 486
 487 /* Type predicates */
 488
 489 extern int pointer_type (struct type *);
 490
 491 /* Checks Binary and Unary operations for semantic type correctness.  */
 492 /* FIXME:  Does not appear to be used.  */
 493 #define unop_type_check(v,o) binop_type_check((v),NULL,(o))
 494
 495 extern void binop_type_check (struct value *, struct value *, int);
 496
 497 /* Error messages */
 498
 499 extern void type_error (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
 500
 501 extern void range_error (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
 502
 503 /* Data:  Does this value represent "truth" to the current language?  */
 504
 505 extern int value_true (struct value *);
 506
 507 /* Misc:  The string representing a particular enum language.  */
 508
 509 extern enum language language_enum (char *str);
 510
 511 extern const struct language_defn *language_def (enum language);
 512
 513 extern char *language_str (enum language);
 514
 515 /* Add a language to the set known by GDB (at initialization time).  */
 516
 517 extern void add_language (const struct language_defn *);
 518
 519 extern enum language get_frame_language (void); /* In stack.c */
 520
 521 /* Check for a language-specific trampoline.  */
 522
 523 extern CORE_ADDR skip_language_trampoline (struct frame_info *, CORE_ADDR pc);
 524
 525 /* Return demangled language symbol, or NULL.  */
 526 extern char *language_demangle (const struct language_defn *current_language,
 527                                 const char *mangled, int options);
 528
 529 /* Return class name from physname, or NULL.  */
 530 extern char *language_class_name_from_physname (const struct language_defn *,
 531                                                 const char *physname);
 532
 533 /* Splitting strings into words.  */
 534 extern char *default_word_break_characters (void);
 535
 536 /* Print the index of an array element using the C99 syntax.  */
 537 extern void default_print_array_index (struct value *index_value,
 538                                        struct ui_file *stream,
 539                                        const struct value_print_options *options);
 540
 541 /* Return non-zero if TYPE should be passed (and returned) by
 542    reference at the language level.  */
 543 int language_pass_by_reference (struct type *type);
 544
 545 /* Return zero; by default, types are passed by value at the language
 546    level.  The target ABI may pass or return some structs by reference
 547    independent of this.  */
 548 int default_pass_by_reference (struct type *type);
 549
 550 /* The default implementation of la_print_typedef.  */
 551 void default_print_typedef (struct type *type, struct symbol *new_symbol,
 552                             struct ui_file *stream);
 553
 554 void default_get_string (struct value *value, gdb_byte **buffer, int *length,
 555                          struct type **char_type, const char **charset);
 556
 557 void c_get_string (struct value *value, gdb_byte **buffer, int *length,
 558                    struct type **char_type, const char **charset);
 559
 560 #endif /* defined (LANGUAGE_H) */