gdb/language.h

   1 /* Source-language-related definitions for GDB.
   2
   3    Copyright (C) 1991-2018 Free Software Foundation, Inc.
   4
   5    Contributed by the Department of Computer Science at the State University
   6    of New York at Buffalo.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #if !defined (LANGUAGE_H)
  24 #define LANGUAGE_H 1
  25
  26 #include "symtab.h"
  27 #include "common/function-view.h"
  28 #include "expression.h"
  29
  30 /* Forward decls for prototypes.  */
  31 struct value;
  32 struct objfile;
  33 struct frame_info;
  34 struct ui_file;
  35 struct value_print_options;
  36 struct type_print_options;
  37 struct lang_varobj_ops;
  38 struct parser_state;
  39 struct compile_instance;
  40 struct completion_match_for_lcd;
  41
  42 #define MAX_FORTRAN_DIMS  7     /* Maximum number of F77 array dims.  */
  43
  44 /* range_mode ==
  45    range_mode_auto:   range_check set automatically to default of language.
  46    range_mode_manual: range_check set manually by user.  */
  47
  48 extern enum range_mode
  49   {
  50     range_mode_auto, range_mode_manual
  51   }
  52 range_mode;
  53
  54 /* range_check ==
  55    range_check_on:    Ranges are checked in GDB expressions, producing errors.
  56    range_check_warn:  Ranges are checked, producing warnings.
  57    range_check_off:   Ranges are not checked in GDB expressions.  */
  58
  59 extern enum range_check
  60   {
  61     range_check_off, range_check_warn, range_check_on
  62   }
  63 range_check;
  64
  65 /* case_mode ==
  66    case_mode_auto:   case_sensitivity set upon selection of scope.
  67    case_mode_manual: case_sensitivity set only by user.  */
  68
  69 extern enum case_mode
  70   {
  71     case_mode_auto, case_mode_manual
  72   }
  73 case_mode;
  74
  75 /* array_ordering ==
  76    array_row_major:     Arrays are in row major order.
  77    array_column_major:  Arrays are in column major order.  */
  78
  79 extern enum array_ordering
  80   {
  81     array_row_major, array_column_major
  82   }
  83 array_ordering;
  84
  85
  86 /* case_sensitivity ==
  87    case_sensitive_on:   Case sensitivity in name matching is used.
  88    case_sensitive_off:  Case sensitivity in name matching is not used.  */
  89
  90 extern enum case_sensitivity
  91   {
  92     case_sensitive_on, case_sensitive_off
  93   }
  94 case_sensitivity;
  95
  96
  97 /* macro_expansion ==
  98    macro_expansion_no:  No macro expansion is available.
  99    macro_expansion_c:   C-like macro expansion is available.  */
 100
 101 enum macro_expansion
 102   {
 103     macro_expansion_no, macro_expansion_c
 104   };
 105
 106 \f
 107 /* Per architecture (OS/ABI) language information.  */
 108
 109 struct language_arch_info
 110 {
 111   /* Its primitive types.  This is a vector ended by a NULL pointer.
 112      These types can be specified by name in parsing types in
 113      expressions, regardless of whether the program being debugged
 114      actually defines such a type.  */
 115   struct type **primitive_type_vector;
 116
 117   /* Symbol wrappers around primitive_type_vector, so that the symbol lookup
 118      machinery can return them.  */
 119   struct symbol **primitive_type_symbols;
 120
 121   /* Type of elements of strings.  */
 122   struct type *string_char_type;
 123
 124   /* Symbol name of type to use as boolean type, if defined.  */
 125   const char *bool_type_symbol;
 126   /* Otherwise, this is the default boolean builtin type.  */
 127   struct type *bool_type_default;
 128 };
 129
 130 /* Structure tying together assorted information about a language.  */
 131
 132 struct language_defn
 133   {
 134     /* Name of the language.  */
 135
 136     const char *la_name;
 137
 138     /* Natural or official name of the language.  */
 139
 140     const char *la_natural_name;
 141
 142     /* its symtab language-enum (defs.h).  */
 143
 144     enum language la_language;
 145
 146     /* Default range checking.  */
 147
 148     enum range_check la_range_check;
 149
 150     /* Default case sensitivity.  */
 151     enum case_sensitivity la_case_sensitivity;
 152
 153     /* Multi-dimensional array ordering.  */
 154     enum array_ordering la_array_ordering;
 155
 156     /* Style of macro expansion, if any, supported by this language.  */
 157     enum macro_expansion la_macro_expansion;
 158
 159     /* A NULL-terminated array of file extensions for this language.
 160        The extension must include the ".", like ".c".  If this
 161        language doesn't need to provide any filename extensions, this
 162        may be NULL.  */
 163
 164     const char *const *la_filename_extensions;
 165
 166     /* Definitions related to expression printing, prefixifying, and
 167        dumping.  */
 168
 169     const struct exp_descriptor *la_exp_desc;
 170
 171     /* Parser function.  */
 172
 173     int (*la_parser) (struct parser_state *);
 174
 175     /* Given an expression *EXPP created by prefixifying the result of
 176        la_parser, perform any remaining processing necessary to complete
 177        its translation.  *EXPP may change; la_post_parser is responsible
 178        for releasing its previous contents, if necessary.  If
 179        VOID_CONTEXT_P, then no value is expected from the expression.  */
 180
 181     void (*la_post_parser) (expression_up *expp, int void_context_p);
 182
 183     void (*la_printchar) (int ch, struct type *chtype,
 184                           struct ui_file * stream);
 185
 186     void (*la_printstr) (struct ui_file * stream, struct type *elttype,
 187                          const gdb_byte *string, unsigned int length,
 188                          const char *encoding, int force_ellipses,
 189                          const struct value_print_options *);
 190
 191     void (*la_emitchar) (int ch, struct type *chtype,
 192                          struct ui_file * stream, int quoter);
 193
 194     /* Print a type using syntax appropriate for this language.  */
 195
 196     void (*la_print_type) (struct type *, const char *, struct ui_file *, int,
 197                            int, const struct type_print_options *);
 198
 199     /* Print a typedef using syntax appropriate for this language.
 200        TYPE is the underlying type.  NEW_SYMBOL is the symbol naming
 201        the type.  STREAM is the output stream on which to print.  */
 202
 203     void (*la_print_typedef) (struct type *type, struct symbol *new_symbol,
 204                               struct ui_file *stream);
 205
 206     /* Print a value using syntax appropriate for this language.
 207
 208        TYPE is the type of the sub-object to be printed.
 209
 210        EMBEDDED_OFFSET is the offset into the outermost object of the
 211        sub-object represented by TYPE.  This is the object which this
 212        call should print.  Note that the enclosing type is not
 213        available.
 214
 215        ADDRESS is the address in the inferior of the enclosing object.
 216
 217        STREAM is the stream on which the value is to be printed.
 218
 219        RECURSE is the recursion depth.  It is zero-based.
 220
 221        OPTIONS are the formatting options to be used when
 222        printing.  */
 223
 224     void (*la_val_print) (struct type *type,
 225                           int embedded_offset, CORE_ADDR address,
 226                           struct ui_file *stream, int recurse,
 227                           struct value *val,
 228                           const struct value_print_options *options);
 229
 230     /* Print a top-level value using syntax appropriate for this language.  */
 231
 232     void (*la_value_print) (struct value *, struct ui_file *,
 233                             const struct value_print_options *);
 234
 235     /* Given a symbol VAR, the corresponding block VAR_BLOCK (if any) and a
 236        stack frame id FRAME, read the value of the variable and return (pointer
 237        to a) struct value containing the value.
 238
 239        VAR_BLOCK is needed if there's a possibility for VAR to be outside
 240        FRAME.  This is what happens if FRAME correspond to a nested function
 241        and VAR is defined in the outer function.  If callers know that VAR is
 242        located in FRAME or is global/static, NULL can be passed as VAR_BLOCK.
 243
 244        Throw an error if the variable cannot be found.  */
 245
 246     struct value *(*la_read_var_value) (struct symbol *var,
 247                                         const struct block *var_block,
 248                                         struct frame_info *frame);
 249
 250     /* PC is possibly an unknown languages trampoline.
 251        If that PC falls in a trampoline belonging to this language,
 252        return the address of the first pc in the real function, or 0
 253        if it isn't a language tramp for this language.  */
 254     CORE_ADDR (*skip_trampoline) (struct frame_info *, CORE_ADDR);
 255
 256     /* Now come some hooks for lookup_symbol.  */
 257
 258     /* If this is non-NULL, specifies the name that of the implicit
 259        local variable that refers to the current object instance.  */
 260
 261     const char *la_name_of_this;
 262
 263     /* True if the symbols names should be stored in GDB's data structures
 264        for minimal/partial/full symbols using their linkage (aka mangled)
 265        form; false if the symbol names should be demangled first.
 266
 267        Most languages implement symbol lookup by comparing the demangled
 268        names, in which case it is advantageous to store that information
 269        already demangled, and so would set this field to false.
 270
 271        On the other hand, some languages have opted for doing symbol
 272        lookups by comparing mangled names instead, for reasons usually
 273        specific to the language.  Those languages should set this field
 274        to true.
 275
 276        And finally, other languages such as C or Asm do not have
 277        the concept of mangled vs demangled name, so those languages
 278        should set this field to true as well, to prevent any accidental
 279        demangling through an unrelated language's demangler.  */
 280
 281     const bool la_store_sym_names_in_linkage_form_p;
 282
 283     /* This is a function that lookup_symbol will call when it gets to
 284        the part of symbol lookup where C looks up static and global
 285        variables.  */
 286
 287     struct block_symbol (*la_lookup_symbol_nonlocal)
 288       (const struct language_defn *,
 289        const char *,
 290        const struct block *,
 291        const domain_enum);
 292
 293     /* Find the definition of the type with the given name.  */
 294     struct type *(*la_lookup_transparent_type) (const char *);
 295
 296     /* Return demangled language symbol, or NULL.  */
 297     char *(*la_demangle) (const char *mangled, int options);
 298
 299     /* Demangle a symbol according to this language's rules.  Unlike
 300        la_demangle, this does not take any options.
 301
 302        *DEMANGLED will be set by this function.
 303
 304        If this function returns 0, then *DEMANGLED must always be set
 305        to NULL.
 306
 307        If this function returns 1, the implementation may set this to
 308        a xmalloc'd string holding the demangled form.  However, it is
 309        not required to.  The string, if any, is owned by the caller.
 310
 311        The resulting string should be of the form that will be
 312        installed into a symbol.  */
 313     int (*la_sniff_from_mangled_name) (const char *mangled, char **demangled);
 314
 315     /* Return class name of a mangled method name or NULL.  */
 316     char *(*la_class_name_from_physname) (const char *physname);
 317
 318     /* Table for printing expressions.  */
 319
 320     const struct op_print *la_op_print_tab;
 321
 322     /* Zero if the language has first-class arrays.  True if there are no
 323        array values, and array objects decay to pointers, as in C.  */
 324
 325     char c_style_arrays;
 326
 327     /* Index to use for extracting the first element of a string.  */
 328     char string_lower_bound;
 329
 330     /* The list of characters forming word boundaries.  */
 331     const char *(*la_word_break_characters) (void);
 332
 333     /* Add to the completion tracker all symbols which are possible
 334        completions for TEXT.  WORD is the entire command on which the
 335        completion is being made.  If CODE is TYPE_CODE_UNDEF, then all
 336        symbols should be examined; otherwise, only STRUCT_DOMAIN
 337        symbols whose type has a code of CODE should be matched.  */
 338     void (*la_collect_symbol_completion_matches)
 339       (completion_tracker &tracker,
 340        complete_symbol_mode mode,
 341        symbol_name_match_type match_type,
 342        const char *text,
 343        const char *word,
 344        enum type_code code);
 345
 346     /* The per-architecture (OS/ABI) language information.  */
 347     void (*la_language_arch_info) (struct gdbarch *,
 348                                    struct language_arch_info *);
 349
 350     /* Print the index of an element of an array.  */
 351     void (*la_print_array_index) (struct value *index_value,
 352                                   struct ui_file *stream,
 353                                   const struct value_print_options *options);
 354
 355     /* Return non-zero if TYPE should be passed (and returned) by
 356        reference at the language level.  */
 357     int (*la_pass_by_reference) (struct type *type);
 358
 359     /* Obtain a string from the inferior, storing it in a newly allocated
 360        buffer in BUFFER, which should be freed by the caller.  If the
 361        in- and out-parameter *LENGTH is specified at -1, the string is
 362        read until a null character of the appropriate width is found -
 363        otherwise the string is read to the length of characters specified.
 364        On completion, *LENGTH will hold the size of the string in characters.
 365        If a *LENGTH of -1 was specified it will count only actual
 366        characters, excluding any eventual terminating null character.
 367        Otherwise *LENGTH will include all characters - including any nulls.
 368        CHARSET will hold the encoding used in the string.  */
 369     void (*la_get_string) (struct value *value,
 370                            gdb::unique_xmalloc_ptr<gdb_byte> *buffer,
 371                            int *length, struct type **chartype,
 372                            const char **charset);
 373
 374     /* Return an expression that can be used for a location
 375        watchpoint.  TYPE is a pointer type that points to the memory
 376        to watch, and ADDR is the address of the watched memory.  */
 377     gdb::unique_xmalloc_ptr<char> (*la_watch_location_expression)
 378          (struct type *type, CORE_ADDR addr);
 379
 380     /* Return a pointer to the function that should be used to match a
 381        symbol name against LOOKUP_NAME, according to this language's
 382        rules.  The matching algorithm depends on LOOKUP_NAME.  For
 383        example, on Ada, the matching algorithm depends on the symbol
 384        name (wild/full/verbatim matching), and on whether we're doing
 385        a normal lookup or a completion match lookup.
 386
 387        This field may be NULL, in which case
 388        default_symbol_name_matcher is used to perform the
 389        matching.  */
 390     symbol_name_matcher_ftype *(*la_get_symbol_name_matcher)
 391       (const lookup_name_info &);
 392
 393     /* Find all symbols in the current program space matching NAME in
 394        DOMAIN, according to this language's rules.
 395
 396        The search is done in BLOCK only.
 397        The caller is responsible for iterating up through superblocks
 398        if desired.
 399
 400        For each one, call CALLBACK with the symbol.  If CALLBACK
 401        returns false, the iteration ends at that point.
 402
 403        This field may not be NULL.  If the language does not need any
 404        special processing here, 'iterate_over_symbols' should be
 405        used as the definition.  */
 406     void (*la_iterate_over_symbols)
 407       (const struct block *block, const lookup_name_info &name,
 408        domain_enum domain,
 409        gdb::function_view<symbol_found_callback_ftype> callback);
 410
 411     /* Hash the given symbol search name.  Use
 412        default_search_name_hash if no special treatment is
 413        required.  */
 414     unsigned int (*la_search_name_hash) (const char *name);
 415
 416     /* Various operations on varobj.  */
 417     const struct lang_varobj_ops *la_varobj_ops;
 418
 419     /* If this language allows compilation from the gdb command line,
 420        this method should be non-NULL.  When called it should return
 421        an instance of struct gcc_context appropriate to the language.
 422        When defined this method must never return NULL; instead it
 423        should throw an exception on failure.  The returned compiler
 424        instance is owned by its caller and must be deallocated by
 425        calling its 'destroy' method.  */
 426
 427     struct compile_instance *(*la_get_compile_instance) (void);
 428
 429     /* This method must be defined if 'la_get_gcc_context' is defined.
 430        If 'la_get_gcc_context' is not defined, then this method is
 431        ignored.
 432
 433        This takes the user-supplied text and returns a new bit of code
 434        to compile.
 435
 436        INST is the compiler instance being used.
 437        INPUT is the user's input text.
 438        GDBARCH is the architecture to use.
 439        EXPR_BLOCK is the block in which the expression is being
 440        parsed.
 441        EXPR_PC is the PC at which the expression is being parsed.  */
 442
 443     std::string (*la_compute_program) (struct compile_instance *inst,
 444                                        const char *input,
 445                                        struct gdbarch *gdbarch,
 446                                        const struct block *expr_block,
 447                                        CORE_ADDR expr_pc);
 448
 449     /* Add fields above this point, so the magic number is always last.  */
 450     /* Magic number for compat checking.  */
 451
 452     long la_magic;
 453
 454   };
 455
 456 #define LANG_MAGIC      910823L
 457
 458 /* Pointer to the language_defn for our current language.  This pointer
 459    always points to *some* valid struct; it can be used without checking
 460    it for validity.
 461
 462    The current language affects expression parsing and evaluation
 463    (FIXME: it might be cleaner to make the evaluation-related stuff
 464    separate exp_opcodes for each different set of semantics.  We
 465    should at least think this through more clearly with respect to
 466    what happens if the language is changed between parsing and
 467    evaluation) and printing of things like types and arrays.  It does
 468    *not* affect symbol-reading-- each source file in a symbol-file has
 469    its own language and we should keep track of that regardless of the
 470    language when symbols are read.  If we want some manual setting for
 471    the language of symbol files (e.g. detecting when ".c" files are
 472    C++), it should be a separate setting from the current_language.  */
 473
 474 extern const struct language_defn *current_language;
 475
 476 /* Pointer to the language_defn expected by the user, e.g. the language
 477    of main(), or the language we last mentioned in a message, or C.  */
 478
 479 extern const struct language_defn *expected_language;
 480
 481 /* language_mode ==
 482    language_mode_auto:   current_language automatically set upon selection
 483    of scope (e.g. stack frame)
 484    language_mode_manual: current_language set only by user.  */
 485
 486 extern enum language_mode
 487   {
 488     language_mode_auto, language_mode_manual
 489   }
 490 language_mode;
 491
 492 struct type *language_bool_type (const struct language_defn *l,
 493                                  struct gdbarch *gdbarch);
 494
 495 struct type *language_string_char_type (const struct language_defn *l,
 496                                         struct gdbarch *gdbarch);
 497
 498 /* Look up type NAME in language L, and return its definition for architecture
 499    GDBARCH.  Returns NULL if not found.  */
 500
 501 struct type *language_lookup_primitive_type (const struct language_defn *l,
 502                                              struct gdbarch *gdbarch,
 503                                              const char *name);
 504
 505 /* Wrapper around language_lookup_primitive_type to return the
 506    corresponding symbol.  */
 507
 508 struct symbol *
 509   language_lookup_primitive_type_as_symbol (const struct language_defn *l,
 510                                             struct gdbarch *gdbarch,
 511                                             const char *name);
 512
 513 \f
 514 /* These macros define the behaviour of the expression
 515    evaluator.  */
 516
 517 /* Should we range check values against the domain of their type?  */
 518 #define RANGE_CHECK (range_check != range_check_off)
 519
 520 /* "cast" really means conversion.  */
 521 /* FIXME -- should be a setting in language_defn.  */
 522 #define CAST_IS_CONVERSION(LANG) ((LANG)->la_language == language_c  || \
 523                                   (LANG)->la_language == language_cplus || \
 524                                   (LANG)->la_language == language_objc)
 525
 526 extern void language_info (int);
 527
 528 extern enum language set_language (enum language);
 529 \f
 530
 531 /* This page contains functions that return things that are
 532    specific to languages.  Each of these functions is based on
 533    the current setting of working_lang, which the user sets
 534    with the "set language" command.  */
 535
 536 #define LA_PRINT_TYPE(type,varstring,stream,show,level,flags)           \
 537   (current_language->la_print_type(type,varstring,stream,show,level,flags))
 538
 539 #define LA_PRINT_TYPEDEF(type,new_symbol,stream) \
 540   (current_language->la_print_typedef(type,new_symbol,stream))
 541
 542 #define LA_VALUE_PRINT(val,stream,options) \
 543   (current_language->la_value_print(val,stream,options))
 544
 545 #define LA_PRINT_CHAR(ch, type, stream) \
 546   (current_language->la_printchar(ch, type, stream))
 547 #define LA_PRINT_STRING(stream, elttype, string, length, encoding, force_ellipses, options) \
 548   (current_language->la_printstr(stream, elttype, string, length, \
 549                                  encoding, force_ellipses,options))
 550 #define LA_EMIT_CHAR(ch, type, stream, quoter) \
 551   (current_language->la_emitchar(ch, type, stream, quoter))
 552 #define LA_GET_STRING(value, buffer, length, chartype, encoding) \
 553   (current_language->la_get_string(value, buffer, length, chartype, encoding))
 554
 555 #define LA_PRINT_ARRAY_INDEX(index_value, stream, options) \
 556   (current_language->la_print_array_index(index_value, stream, options))
 557
 558 #define LA_ITERATE_OVER_SYMBOLS(BLOCK, NAME, DOMAIN, CALLBACK) \
 559   (current_language->la_iterate_over_symbols (BLOCK, NAME, DOMAIN, CALLBACK))
 560
 561 /* Test a character to decide whether it can be printed in literal form
 562    or needs to be printed in another representation.  For example,
 563    in C the literal form of the character with octal value 141 is 'a'
 564    and the "other representation" is '\141'.  The "other representation"
 565    is program language dependent.  */
 566
 567 #define PRINT_LITERAL_FORM(c)           \
 568   ((c) >= 0x20                          \
 569    && ((c) < 0x7F || (c) >= 0xA0)       \
 570    && (!sevenbit_strings || (c) < 0x80))
 571
 572 /* Type predicates */
 573
 574 extern int pointer_type (struct type *);
 575
 576 /* Error messages */
 577
 578 extern void range_error (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
 579
 580 /* Data:  Does this value represent "truth" to the current language?  */
 581
 582 extern int value_true (struct value *);
 583
 584 /* Misc:  The string representing a particular enum language.  */
 585
 586 extern enum language language_enum (const char *str);
 587
 588 extern const struct language_defn *language_def (enum language);
 589
 590 extern const char *language_str (enum language);
 591
 592 /* Check for a language-specific trampoline.  */
 593
 594 extern CORE_ADDR skip_language_trampoline (struct frame_info *, CORE_ADDR pc);
 595
 596 /* Return demangled language symbol, or NULL.  */
 597 extern char *language_demangle (const struct language_defn *current_language,
 598                                 const char *mangled, int options);
 599
 600 /* A wrapper for la_sniff_from_mangled_name.  The arguments and result
 601    are as for the method.  */
 602
 603 extern int language_sniff_from_mangled_name (const struct language_defn *lang,
 604                                              const char *mangled,
 605                                              char **demangled);
 606
 607 /* Return class name from physname, or NULL.  */
 608 extern char *language_class_name_from_physname (const struct language_defn *,
 609                                                 const char *physname);
 610
 611 /* Splitting strings into words.  */
 612 extern const char *default_word_break_characters (void);
 613
 614 /* Print the index of an array element using the C99 syntax.  */
 615 extern void default_print_array_index (struct value *index_value,
 616                                        struct ui_file *stream,
 617                                        const struct value_print_options *options);
 618
 619 /* Return non-zero if TYPE should be passed (and returned) by
 620    reference at the language level.  */
 621 int language_pass_by_reference (struct type *type);
 622
 623 /* Return zero; by default, types are passed by value at the language
 624    level.  The target ABI may pass or return some structs by reference
 625    independent of this.  */
 626 int default_pass_by_reference (struct type *type);
 627
 628 /* The default implementation of la_print_typedef.  */
 629 void default_print_typedef (struct type *type, struct symbol *new_symbol,
 630                             struct ui_file *stream);
 631
 632 void default_get_string (struct value *value,
 633                          gdb::unique_xmalloc_ptr<gdb_byte> *buffer,
 634                          int *length, struct type **char_type,
 635                          const char **charset);
 636
 637 /* Default name hashing function.  */
 638
 639 /* Produce an unsigned hash value from SEARCH_NAME that is consistent
 640    with strcmp_iw, strcmp, and, at least on Ada symbols, wild_match.
 641    That is, two identifiers equivalent according to any of those three
 642    comparison operators hash to the same value.  */
 643 extern unsigned int default_search_name_hash (const char *search_name);
 644
 645 void c_get_string (struct value *value,
 646                    gdb::unique_xmalloc_ptr<gdb_byte> *buffer,
 647                    int *length, struct type **char_type,
 648                    const char **charset);
 649
 650 /* The default implementation of la_symbol_name_matcher.  Matches with
 651    strncmp_iw.  */
 652 extern bool default_symbol_name_matcher
 653   (const char *symbol_search_name,
 654    const lookup_name_info &lookup_name,
 655    completion_match_result *comp_match_res);
 656
 657 /* Get LANG's symbol_name_matcher method for LOOKUP_NAME.  Returns
 658    default_symbol_name_matcher if not set.  LANG is used as a hint;
 659    the function may ignore it depending on the current language and
 660    LOOKUP_NAME.  Specifically, if the current language is Ada, this
 661    may return an Ada matcher regardless of LANG.  */
 662 symbol_name_matcher_ftype *get_symbol_name_matcher
 663   (const language_defn *lang, const lookup_name_info &lookup_name);
 664
 665 /* The languages supported by GDB.  */
 666
 667 extern const struct language_defn auto_language_defn;
 668 extern const struct language_defn unknown_language_defn;
 669 extern const struct language_defn minimal_language_defn;
 670
 671 extern const struct language_defn ada_language_defn;
 672 extern const struct language_defn asm_language_defn;
 673 extern const struct language_defn c_language_defn;
 674 extern const struct language_defn cplus_language_defn;
 675 extern const struct language_defn d_language_defn;
 676 extern const struct language_defn f_language_defn;
 677 extern const struct language_defn go_language_defn;
 678 extern const struct language_defn m2_language_defn;
 679 extern const struct language_defn objc_language_defn;
 680 extern const struct language_defn opencl_language_defn;
 681 extern const struct language_defn pascal_language_defn;
 682 extern const struct language_defn rust_language_defn;
 683
 684 /* Save the current language and restore it upon destruction.  */
 685
 686 class scoped_restore_current_language
 687 {
 688 public:
 689
 690   explicit scoped_restore_current_language ()
 691     : m_lang (current_language->la_language)
 692   {
 693   }
 694
 695   ~scoped_restore_current_language ()
 696   {
 697     set_language (m_lang);
 698   }
 699
 700   scoped_restore_current_language (const scoped_restore_current_language &)
 701       = delete;
 702   scoped_restore_current_language &operator=
 703       (const scoped_restore_current_language &) = delete;
 704
 705 private:
 706
 707   enum language m_lang;
 708 };
 709
 710 #endif /* defined (LANGUAGE_H) */