gdb/language.h

   1 /* Source-language-related definitions for GDB.
   2
   3    Copyright (C) 1991-2017 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
  29 /* Forward decls for prototypes.  */
  30 struct value;
  31 struct objfile;
  32 struct frame_info;
  33 struct expression;
  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
  41 #define MAX_FORTRAN_DIMS  7     /* Maximum number of F77 array dims.  */
  42
  43 /* range_mode ==
  44    range_mode_auto:   range_check set automatically to default of language.
  45    range_mode_manual: range_check set manually by user.  */
  46
  47 extern enum range_mode
  48   {
  49     range_mode_auto, range_mode_manual
  50   }
  51 range_mode;
  52
  53 /* range_check ==
  54    range_check_on:    Ranges are checked in GDB expressions, producing errors.
  55    range_check_warn:  Ranges are checked, producing warnings.
  56    range_check_off:   Ranges are not checked in GDB expressions.  */
  57
  58 extern enum range_check
  59   {
  60     range_check_off, range_check_warn, range_check_on
  61   }
  62 range_check;
  63
  64 /* case_mode ==
  65    case_mode_auto:   case_sensitivity set upon selection of scope.
  66    case_mode_manual: case_sensitivity set only by user.  */
  67
  68 extern enum case_mode
  69   {
  70     case_mode_auto, case_mode_manual
  71   }
  72 case_mode;
  73
  74 /* array_ordering ==
  75    array_row_major:     Arrays are in row major order.
  76    array_column_major:  Arrays are in column major order.  */
  77
  78 extern enum array_ordering
  79   {
  80     array_row_major, array_column_major
  81   }
  82 array_ordering;
  83
  84
  85 /* case_sensitivity ==
  86    case_sensitive_on:   Case sensitivity in name matching is used.
  87    case_sensitive_off:  Case sensitivity in name matching is not used.  */
  88
  89 extern enum case_sensitivity
  90   {
  91     case_sensitive_on, case_sensitive_off
  92   }
  93 case_sensitivity;
  94
  95
  96 /* macro_expansion ==
  97    macro_expansion_no:  No macro expansion is available.
  98    macro_expansion_c:   C-like macro expansion is available.  */
  99
 100 enum macro_expansion
 101   {
 102     macro_expansion_no, macro_expansion_c
 103   };
 104
 105 \f
 106 /* Per architecture (OS/ABI) language information.  */
 107
 108 struct language_arch_info
 109 {
 110   /* Its primitive types.  This is a vector ended by a NULL pointer.
 111      These types can be specified by name in parsing types in
 112      expressions, regardless of whether the program being debugged
 113      actually defines such a type.  */
 114   struct type **primitive_type_vector;
 115
 116   /* Symbol wrappers around primitive_type_vector, so that the symbol lookup
 117      machinery can return them.  */
 118   struct symbol **primitive_type_symbols;
 119
 120   /* Type of elements of strings.  */
 121   struct type *string_char_type;
 122
 123   /* Symbol name of type to use as boolean type, if defined.  */
 124   const char *bool_type_symbol;
 125   /* Otherwise, this is the default boolean builtin type.  */
 126   struct type *bool_type_default;
 127 };
 128
 129 /* Structure tying together assorted information about a language.  */
 130
 131 struct language_defn
 132   {
 133     /* Name of the language.  */
 134
 135     const char *la_name;
 136
 137     /* Natural or official name of the language.  */
 138
 139     const char *la_natural_name;
 140
 141     /* its symtab language-enum (defs.h).  */
 142
 143     enum language la_language;
 144
 145     /* Default range checking.  */
 146
 147     enum range_check la_range_check;
 148
 149     /* Default case sensitivity.  */
 150     enum case_sensitivity la_case_sensitivity;
 151
 152     /* Multi-dimensional array ordering.  */
 153     enum array_ordering la_array_ordering;
 154
 155     /* Style of macro expansion, if any, supported by this language.  */
 156     enum macro_expansion la_macro_expansion;
 157
 158     /* A NULL-terminated array of file extensions for this language.
 159        The extension must include the ".", like ".c".  If this
 160        language doesn't need to provide any filename extensions, this
 161        may be NULL.  */
 162
 163     const char *const *la_filename_extensions;
 164
 165     /* Definitions related to expression printing, prefixifying, and
 166        dumping.  */
 167
 168     const struct exp_descriptor *la_exp_desc;
 169
 170     /* Parser function.  */
 171
 172     int (*la_parser) (struct parser_state *);
 173
 174     /* Parser error function.  */
 175
 176     void (*la_error) (const char *);
 177
 178     /* Given an expression *EXPP created by prefixifying the result of
 179        la_parser, perform any remaining processing necessary to complete
 180        its translation.  *EXPP may change; la_post_parser is responsible
 181        for releasing its previous contents, if necessary.  If
 182        VOID_CONTEXT_P, then no value is expected from the expression.  */
 183
 184     void (*la_post_parser) (struct expression ** expp, int void_context_p);
 185
 186     void (*la_printchar) (int ch, struct type *chtype,
 187                           struct ui_file * stream);
 188
 189     void (*la_printstr) (struct ui_file * stream, struct type *elttype,
 190                          const gdb_byte *string, unsigned int length,
 191                          const char *encoding, int force_ellipses,
 192                          const struct value_print_options *);
 193
 194     void (*la_emitchar) (int ch, struct type *chtype,
 195                          struct ui_file * stream, int quoter);
 196
 197     /* Print a type using syntax appropriate for this language.  */
 198
 199     void (*la_print_type) (struct type *, const char *, struct ui_file *, int,
 200                            int, const struct type_print_options *);
 201
 202     /* Print a typedef using syntax appropriate for this language.
 203        TYPE is the underlying type.  NEW_SYMBOL is the symbol naming
 204        the type.  STREAM is the output stream on which to print.  */
 205
 206     void (*la_print_typedef) (struct type *type, struct symbol *new_symbol,
 207                               struct ui_file *stream);
 208
 209     /* Print a value using syntax appropriate for this language.
 210
 211        TYPE is the type of the sub-object to be printed.
 212
 213        EMBEDDED_OFFSET is the offset into the outermost object of the
 214        sub-object represented by TYPE.  This is the object which this
 215        call should print.  Note that the enclosing type is not
 216        available.
 217
 218        ADDRESS is the address in the inferior of the enclosing object.
 219
 220        STREAM is the stream on which the value is to be printed.
 221
 222        RECURSE is the recursion depth.  It is zero-based.
 223
 224        OPTIONS are the formatting options to be used when
 225        printing.  */
 226
 227     void (*la_val_print) (struct type *type,
 228                           int embedded_offset, CORE_ADDR address,
 229                           struct ui_file *stream, int recurse,
 230                           struct value *val,
 231                           const struct value_print_options *options);
 232
 233     /* Print a top-level value using syntax appropriate for this language.  */
 234
 235     void (*la_value_print) (struct value *, struct ui_file *,
 236                             const struct value_print_options *);
 237
 238     /* Given a symbol VAR, the corresponding block VAR_BLOCK (if any) and a
 239        stack frame id FRAME, read the value of the variable and return (pointer
 240        to a) struct value containing the value.
 241
 242        VAR_BLOCK is needed if there's a possibility for VAR to be outside
 243        FRAME.  This is what happens if FRAME correspond to a nested function
 244        and VAR is defined in the outer function.  If callers know that VAR is
 245        located in FRAME or is global/static, NULL can be passed as VAR_BLOCK.
 246
 247        Throw an error if the variable cannot be found.  */
 248
 249     struct value *(*la_read_var_value) (struct symbol *var,
 250                                         const struct block *var_block,
 251                                         struct frame_info *frame);
 252
 253     /* PC is possibly an unknown languages trampoline.
 254        If that PC falls in a trampoline belonging to this language,
 255        return the address of the first pc in the real function, or 0
 256        if it isn't a language tramp for this language.  */
 257     CORE_ADDR (*skip_trampoline) (struct frame_info *, CORE_ADDR);
 258
 259     /* Now come some hooks for lookup_symbol.  */
 260
 261     /* If this is non-NULL, specifies the name that of the implicit
 262        local variable that refers to the current object instance.  */
 263
 264     const char *la_name_of_this;
 265
 266     /* This is a function that lookup_symbol will call when it gets to
 267        the part of symbol lookup where C looks up static and global
 268        variables.  */
 269
 270     struct block_symbol (*la_lookup_symbol_nonlocal)
 271       (const struct language_defn *,
 272        const char *,
 273        const struct block *,
 274        const domain_enum);
 275
 276     /* Find the definition of the type with the given name.  */
 277     struct type *(*la_lookup_transparent_type) (const char *);
 278
 279     /* Return demangled language symbol, or NULL.  */
 280     char *(*la_demangle) (const char *mangled, int options);
 281
 282     /* Demangle a symbol according to this language's rules.  Unlike
 283        la_demangle, this does not take any options.
 284
 285        *DEMANGLED will be set by this function.
 286
 287        If this function returns 0, then *DEMANGLED must always be set
 288        to NULL.
 289
 290        If this function returns 1, the implementation may set this to
 291        a xmalloc'd string holding the demangled form.  However, it is
 292        not required to.  The string, if any, is owned by the caller.
 293
 294        The resulting string should be of the form that will be
 295        installed into a symbol.  */
 296     int (*la_sniff_from_mangled_name) (const char *mangled, char **demangled);
 297
 298     /* Return class name of a mangled method name or NULL.  */
 299     char *(*la_class_name_from_physname) (const char *physname);
 300
 301     /* Table for printing expressions.  */
 302
 303     const struct op_print *la_op_print_tab;
 304
 305     /* Zero if the language has first-class arrays.  True if there are no
 306        array values, and array objects decay to pointers, as in C.  */
 307
 308     char c_style_arrays;
 309
 310     /* Index to use for extracting the first element of a string.  */
 311     char string_lower_bound;
 312
 313     /* The list of characters forming word boundaries.  */
 314     const char *(*la_word_break_characters) (void);
 315
 316     /* Add to the completion tracker all symbols which are possible
 317        completions for TEXT.  WORD is the entire command on which the
 318        completion is being made.  If CODE is TYPE_CODE_UNDEF, then all
 319        symbols should be examined; otherwise, only STRUCT_DOMAIN
 320        symbols whose type has a code of CODE should be matched.  */
 321     void (*la_collect_symbol_completion_matches)
 322       (completion_tracker &tracker,
 323        complete_symbol_mode mode,
 324        symbol_name_match_type match_type,
 325        const char *text,
 326        const char *word,
 327        enum type_code code);
 328
 329     /* The per-architecture (OS/ABI) language information.  */
 330     void (*la_language_arch_info) (struct gdbarch *,
 331                                    struct language_arch_info *);
 332
 333     /* Print the index of an element of an array.  */
 334     void (*la_print_array_index) (struct value *index_value,
 335                                   struct ui_file *stream,
 336                                   const struct value_print_options *options);
 337
 338     /* Return non-zero if TYPE should be passed (and returned) by
 339        reference at the language level.  */
 340     int (*la_pass_by_reference) (struct type *type);
 341
 342     /* Obtain a string from the inferior, storing it in a newly allocated
 343        buffer in BUFFER, which should be freed by the caller.  If the
 344        in- and out-parameter *LENGTH is specified at -1, the string is
 345        read until a null character of the appropriate width is found -
 346        otherwise the string is read to the length of characters specified.
 347        On completion, *LENGTH will hold the size of the string in characters.
 348        If a *LENGTH of -1 was specified it will count only actual
 349        characters, excluding any eventual terminating null character.
 350        Otherwise *LENGTH will include all characters - including any nulls.
 351        CHARSET will hold the encoding used in the string.  */
 352     void (*la_get_string) (struct value *value, gdb_byte **buffer, int *length,
 353                            struct type **chartype, const char **charset);
 354
 355     /* Return an expression that can be used for a location
 356        watchpoint.  TYPE is a pointer type that points to the memory
 357        to watch, and ADDR is the address of the watched memory.  */
 358     gdb::unique_xmalloc_ptr<char> (*la_watch_location_expression)
 359          (struct type *type, CORE_ADDR addr);
 360
 361     /* Return a pointer to the function that should be used to match a
 362        symbol name against LOOKUP_NAME, according to this language's
 363        rules.  The matching algorithm depends on LOOKUP_NAME.  For
 364        example, on Ada, the matching algorithm depends on the symbol
 365        name (wild/full/verbatim matching), and on whether we're doing
 366        a normal lookup or a completion match lookup.
 367
 368        This field may be NULL, in which case
 369        default_symbol_name_matcher is used to perform the
 370        matching.  */
 371     symbol_name_matcher_ftype *(*la_get_symbol_name_matcher)
 372       (const lookup_name_info &);
 373
 374     /* Find all symbols in the current program space matching NAME in
 375        DOMAIN, according to this language's rules.
 376
 377        The search is done in BLOCK only.
 378        The caller is responsible for iterating up through superblocks
 379        if desired.
 380
 381        For each one, call CALLBACK with the symbol.  If CALLBACK
 382        returns false, the iteration ends at that point.
 383
 384        This field may not be NULL.  If the language does not need any
 385        special processing here, 'iterate_over_symbols' should be
 386        used as the definition.  */
 387     void (*la_iterate_over_symbols)
 388       (const struct block *block, const lookup_name_info &name,
 389        domain_enum domain,
 390        gdb::function_view<symbol_found_callback_ftype> callback);
 391
 392     /* Hash the given symbol search name.  Use
 393        default_search_name_hash if no special treatment is
 394        required.  */
 395     unsigned int (*la_search_name_hash) (const char *name);
 396
 397     /* Various operations on varobj.  */
 398     const struct lang_varobj_ops *la_varobj_ops;
 399
 400     /* If this language allows compilation from the gdb command line,
 401        this method should be non-NULL.  When called it should return
 402        an instance of struct gcc_context appropriate to the language.
 403        When defined this method must never return NULL; instead it
 404        should throw an exception on failure.  The returned compiler
 405        instance is owned by its caller and must be deallocated by
 406        calling its 'destroy' method.  */
 407
 408     struct compile_instance *(*la_get_compile_instance) (void);
 409
 410     /* This method must be defined if 'la_get_gcc_context' is defined.
 411        If 'la_get_gcc_context' is not defined, then this method is
 412        ignored.
 413
 414        This takes the user-supplied text and returns a new bit of code
 415        to compile.
 416
 417        INST is the compiler instance being used.
 418        INPUT is the user's input text.
 419        GDBARCH is the architecture to use.
 420        EXPR_BLOCK is the block in which the expression is being
 421        parsed.
 422        EXPR_PC is the PC at which the expression is being parsed.  */
 423
 424     std::string (*la_compute_program) (struct compile_instance *inst,
 425                                        const char *input,
 426                                        struct gdbarch *gdbarch,
 427                                        const struct block *expr_block,
 428                                        CORE_ADDR expr_pc);
 429
 430     /* Add fields above this point, so the magic number is always last.  */
 431     /* Magic number for compat checking.  */
 432
 433     long la_magic;
 434
 435   };
 436
 437 #define LANG_MAGIC      910823L
 438
 439 /* Pointer to the language_defn for our current language.  This pointer
 440    always points to *some* valid struct; it can be used without checking
 441    it for validity.
 442
 443    The current language affects expression parsing and evaluation
 444    (FIXME: it might be cleaner to make the evaluation-related stuff
 445    separate exp_opcodes for each different set of semantics.  We
 446    should at least think this through more clearly with respect to
 447    what happens if the language is changed between parsing and
 448    evaluation) and printing of things like types and arrays.  It does
 449    *not* affect symbol-reading-- each source file in a symbol-file has
 450    its own language and we should keep track of that regardless of the
 451    language when symbols are read.  If we want some manual setting for
 452    the language of symbol files (e.g. detecting when ".c" files are
 453    C++), it should be a separate setting from the current_language.  */
 454
 455 extern const struct language_defn *current_language;
 456
 457 /* Pointer to the language_defn expected by the user, e.g. the language
 458    of main(), or the language we last mentioned in a message, or C.  */
 459
 460 extern const struct language_defn *expected_language;
 461
 462 /* language_mode ==
 463    language_mode_auto:   current_language automatically set upon selection
 464    of scope (e.g. stack frame)
 465    language_mode_manual: current_language set only by user.  */
 466
 467 extern enum language_mode
 468   {
 469     language_mode_auto, language_mode_manual
 470   }
 471 language_mode;
 472
 473 struct type *language_bool_type (const struct language_defn *l,
 474                                  struct gdbarch *gdbarch);
 475
 476 struct type *language_string_char_type (const struct language_defn *l,
 477                                         struct gdbarch *gdbarch);
 478
 479 /* Look up type NAME in language L, and return its definition for architecture
 480    GDBARCH.  Returns NULL if not found.  */
 481
 482 struct type *language_lookup_primitive_type (const struct language_defn *l,
 483                                              struct gdbarch *gdbarch,
 484                                              const char *name);
 485
 486 /* Wrapper around language_lookup_primitive_type to return the
 487    corresponding symbol.  */
 488
 489 struct symbol *
 490   language_lookup_primitive_type_as_symbol (const struct language_defn *l,
 491                                             struct gdbarch *gdbarch,
 492                                             const char *name);
 493
 494 \f
 495 /* These macros define the behaviour of the expression
 496    evaluator.  */
 497
 498 /* Should we range check values against the domain of their type?  */
 499 #define RANGE_CHECK (range_check != range_check_off)
 500
 501 /* "cast" really means conversion.  */
 502 /* FIXME -- should be a setting in language_defn.  */
 503 #define CAST_IS_CONVERSION(LANG) ((LANG)->la_language == language_c  || \
 504                                   (LANG)->la_language == language_cplus || \
 505                                   (LANG)->la_language == language_objc)
 506
 507 extern void language_info (int);
 508
 509 extern enum language set_language (enum language);
 510 \f
 511
 512 /* This page contains functions that return things that are
 513    specific to languages.  Each of these functions is based on
 514    the current setting of working_lang, which the user sets
 515    with the "set language" command.  */
 516
 517 #define LA_PRINT_TYPE(type,varstring,stream,show,level,flags)           \
 518   (current_language->la_print_type(type,varstring,stream,show,level,flags))
 519
 520 #define LA_PRINT_TYPEDEF(type,new_symbol,stream) \
 521   (current_language->la_print_typedef(type,new_symbol,stream))
 522
 523 #define LA_VALUE_PRINT(val,stream,options) \
 524   (current_language->la_value_print(val,stream,options))
 525
 526 #define LA_PRINT_CHAR(ch, type, stream) \
 527   (current_language->la_printchar(ch, type, stream))
 528 #define LA_PRINT_STRING(stream, elttype, string, length, encoding, force_ellipses, options) \
 529   (current_language->la_printstr(stream, elttype, string, length, \
 530                                  encoding, force_ellipses,options))
 531 #define LA_EMIT_CHAR(ch, type, stream, quoter) \
 532   (current_language->la_emitchar(ch, type, stream, quoter))
 533 #define LA_GET_STRING(value, buffer, length, chartype, encoding) \
 534   (current_language->la_get_string(value, buffer, length, chartype, encoding))
 535
 536 #define LA_PRINT_ARRAY_INDEX(index_value, stream, options) \
 537   (current_language->la_print_array_index(index_value, stream, options))
 538
 539 #define LA_ITERATE_OVER_SYMBOLS(BLOCK, NAME, DOMAIN, CALLBACK) \
 540   (current_language->la_iterate_over_symbols (BLOCK, NAME, DOMAIN, CALLBACK))
 541
 542 /* Test a character to decide whether it can be printed in literal form
 543    or needs to be printed in another representation.  For example,
 544    in C the literal form of the character with octal value 141 is 'a'
 545    and the "other representation" is '\141'.  The "other representation"
 546    is program language dependent.  */
 547
 548 #define PRINT_LITERAL_FORM(c)           \
 549   ((c) >= 0x20                          \
 550    && ((c) < 0x7F || (c) >= 0xA0)       \
 551    && (!sevenbit_strings || (c) < 0x80))
 552
 553 /* Type predicates */
 554
 555 extern int pointer_type (struct type *);
 556
 557 /* Error messages */
 558
 559 extern void range_error (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
 560
 561 /* Data:  Does this value represent "truth" to the current language?  */
 562
 563 extern int value_true (struct value *);
 564
 565 /* Misc:  The string representing a particular enum language.  */
 566
 567 extern enum language language_enum (const char *str);
 568
 569 extern const struct language_defn *language_def (enum language);
 570
 571 extern const char *language_str (enum language);
 572
 573 /* Check for a language-specific trampoline.  */
 574
 575 extern CORE_ADDR skip_language_trampoline (struct frame_info *, CORE_ADDR pc);
 576
 577 /* Return demangled language symbol, or NULL.  */
 578 extern char *language_demangle (const struct language_defn *current_language,
 579                                 const char *mangled, int options);
 580
 581 /* A wrapper for la_sniff_from_mangled_name.  The arguments and result
 582    are as for the method.  */
 583
 584 extern int language_sniff_from_mangled_name (const struct language_defn *lang,
 585                                              const char *mangled,
 586                                              char **demangled);
 587
 588 /* Return class name from physname, or NULL.  */
 589 extern char *language_class_name_from_physname (const struct language_defn *,
 590                                                 const char *physname);
 591
 592 /* Splitting strings into words.  */
 593 extern const char *default_word_break_characters (void);
 594
 595 /* Print the index of an array element using the C99 syntax.  */
 596 extern void default_print_array_index (struct value *index_value,
 597                                        struct ui_file *stream,
 598                                        const struct value_print_options *options);
 599
 600 /* Return non-zero if TYPE should be passed (and returned) by
 601    reference at the language level.  */
 602 int language_pass_by_reference (struct type *type);
 603
 604 /* Return zero; by default, types are passed by value at the language
 605    level.  The target ABI may pass or return some structs by reference
 606    independent of this.  */
 607 int default_pass_by_reference (struct type *type);
 608
 609 /* The default implementation of la_print_typedef.  */
 610 void default_print_typedef (struct type *type, struct symbol *new_symbol,
 611                             struct ui_file *stream);
 612
 613 void default_get_string (struct value *value, gdb_byte **buffer, int *length,
 614                          struct type **char_type, const char **charset);
 615
 616 /* Default name hashing function.  */
 617
 618 /* Produce an unsigned hash value from SEARCH_NAME that is consistent
 619    with strcmp_iw, strcmp, and, at least on Ada symbols, wild_match.
 620    That is, two identifiers equivalent according to any of those three
 621    comparison operators hash to the same value.  */
 622 extern unsigned int default_search_name_hash (const char *search_name);
 623
 624 void c_get_string (struct value *value, gdb_byte **buffer, int *length,
 625                    struct type **char_type, const char **charset);
 626
 627 /* The default implementation of la_symbol_name_matcher.  Matches with
 628    strncmp_iw.  */
 629 extern bool default_symbol_name_matcher
 630   (const char *symbol_search_name,
 631    const lookup_name_info &lookup_name,
 632    completion_match *match);
 633
 634 /* Get LANG's symbol_name_matcher method for LOOKUP_NAME.  Returns
 635    default_symbol_name_matcher if not set.  */
 636 symbol_name_matcher_ftype *language_get_symbol_name_matcher
 637   (const language_defn *lang, const lookup_name_info &lookup_name);
 638
 639 /* The languages supported by GDB.  */
 640
 641 extern const struct language_defn auto_language_defn;
 642 extern const struct language_defn unknown_language_defn;
 643 extern const struct language_defn minimal_language_defn;
 644
 645 extern const struct language_defn ada_language_defn;
 646 extern const struct language_defn asm_language_defn;
 647 extern const struct language_defn c_language_defn;
 648 extern const struct language_defn cplus_language_defn;
 649 extern const struct language_defn d_language_defn;
 650 extern const struct language_defn f_language_defn;
 651 extern const struct language_defn go_language_defn;
 652 extern const struct language_defn m2_language_defn;
 653 extern const struct language_defn objc_language_defn;
 654 extern const struct language_defn opencl_language_defn;
 655 extern const struct language_defn pascal_language_defn;
 656 extern const struct language_defn rust_language_defn;
 657
 658 /* Save the current language and restore it upon destruction.  */
 659
 660 class scoped_restore_current_language
 661 {
 662 public:
 663
 664   explicit scoped_restore_current_language ()
 665     : m_lang (current_language->la_language)
 666   {
 667   }
 668
 669   ~scoped_restore_current_language ()
 670   {
 671     set_language (m_lang);
 672   }
 673
 674   scoped_restore_current_language (const scoped_restore_current_language &)
 675       = delete;
 676   scoped_restore_current_language &operator=
 677       (const scoped_restore_current_language &) = delete;
 678
 679 private:
 680
 681   enum language m_lang;
 682 };
 683
 684 #endif /* defined (LANGUAGE_H) */