gdb/language.h

   1 /* Source-language-related definitions for GDB.
   2
   3    Copyright (C) 1991-2019 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 class 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        If COMPLETING is non-zero, then the expression has been parsed
 181        for completion, not evaluation.  */
 182
 183     void (*la_post_parser) (expression_up *expp, int void_context_p,
 184                             int completing);
 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     /* True if the symbols names should be stored in GDB's data structures
 267        for minimal/partial/full symbols using their linkage (aka mangled)
 268        form; false if the symbol names should be demangled first.
 269
 270        Most languages implement symbol lookup by comparing the demangled
 271        names, in which case it is advantageous to store that information
 272        already demangled, and so would set this field to false.
 273
 274        On the other hand, some languages have opted for doing symbol
 275        lookups by comparing mangled names instead, for reasons usually
 276        specific to the language.  Those languages should set this field
 277        to true.
 278
 279        And finally, other languages such as C or Asm do not have
 280        the concept of mangled vs demangled name, so those languages
 281        should set this field to true as well, to prevent any accidental
 282        demangling through an unrelated language's demangler.  */
 283
 284     const bool la_store_sym_names_in_linkage_form_p;
 285
 286     /* This is a function that lookup_symbol will call when it gets to
 287        the part of symbol lookup where C looks up static and global
 288        variables.  */
 289
 290     struct block_symbol (*la_lookup_symbol_nonlocal)
 291       (const struct language_defn *,
 292        const char *,
 293        const struct block *,
 294        const domain_enum);
 295
 296     /* Find the definition of the type with the given name.  */
 297     struct type *(*la_lookup_transparent_type) (const char *);
 298
 299     /* Return demangled language symbol, or NULL.  */
 300     char *(*la_demangle) (const char *mangled, int options);
 301
 302     /* Demangle a symbol according to this language's rules.  Unlike
 303        la_demangle, this does not take any options.
 304
 305        *DEMANGLED will be set by this function.
 306
 307        If this function returns 0, then *DEMANGLED must always be set
 308        to NULL.
 309
 310        If this function returns 1, the implementation may set this to
 311        a xmalloc'd string holding the demangled form.  However, it is
 312        not required to.  The string, if any, is owned by the caller.
 313
 314        The resulting string should be of the form that will be
 315        installed into a symbol.  */
 316     int (*la_sniff_from_mangled_name) (const char *mangled, char **demangled);
 317
 318     /* Return class name of a mangled method name or NULL.  */
 319     char *(*la_class_name_from_physname) (const char *physname);
 320
 321     /* Table for printing expressions.  */
 322
 323     const struct op_print *la_op_print_tab;
 324
 325     /* Zero if the language has first-class arrays.  True if there are no
 326        array values, and array objects decay to pointers, as in C.  */
 327
 328     char c_style_arrays;
 329
 330     /* Index to use for extracting the first element of a string.  */
 331     char string_lower_bound;
 332
 333     /* The list of characters forming word boundaries.  */
 334     const char *(*la_word_break_characters) (void);
 335
 336     /* Add to the completion tracker all symbols which are possible
 337        completions for TEXT.  WORD is the entire command on which the
 338        completion is being made.  If CODE is TYPE_CODE_UNDEF, then all
 339        symbols should be examined; otherwise, only STRUCT_DOMAIN
 340        symbols whose type has a code of CODE should be matched.  */
 341     void (*la_collect_symbol_completion_matches)
 342       (completion_tracker &tracker,
 343        complete_symbol_mode mode,
 344        symbol_name_match_type match_type,
 345        const char *text,
 346        const char *word,
 347        enum type_code code);
 348
 349     /* The per-architecture (OS/ABI) language information.  */
 350     void (*la_language_arch_info) (struct gdbarch *,
 351                                    struct language_arch_info *);
 352
 353     /* Print the index of an element of an array.  */
 354     void (*la_print_array_index) (struct value *index_value,
 355                                   struct ui_file *stream,
 356                                   const struct value_print_options *options);
 357
 358     /* Return non-zero if TYPE should be passed (and returned) by
 359        reference at the language level.  */
 360     int (*la_pass_by_reference) (struct type *type);
 361
 362     /* Obtain a string from the inferior, storing it in a newly allocated
 363        buffer in BUFFER, which should be freed by the caller.  If the
 364        in- and out-parameter *LENGTH is specified at -1, the string is
 365        read until a null character of the appropriate width is found -
 366        otherwise the string is read to the length of characters specified.
 367        On completion, *LENGTH will hold the size of the string in characters.
 368        If a *LENGTH of -1 was specified it will count only actual
 369        characters, excluding any eventual terminating null character.
 370        Otherwise *LENGTH will include all characters - including any nulls.
 371        CHARSET will hold the encoding used in the string.  */
 372     void (*la_get_string) (struct value *value,
 373                            gdb::unique_xmalloc_ptr<gdb_byte> *buffer,
 374                            int *length, struct type **chartype,
 375                            const char **charset);
 376
 377     /* Return an expression that can be used for a location
 378        watchpoint.  TYPE is a pointer type that points to the memory
 379        to watch, and ADDR is the address of the watched memory.  */
 380     gdb::unique_xmalloc_ptr<char> (*la_watch_location_expression)
 381          (struct type *type, CORE_ADDR addr);
 382
 383     /* Return a pointer to the function that should be used to match a
 384        symbol name against LOOKUP_NAME, according to this language's
 385        rules.  The matching algorithm depends on LOOKUP_NAME.  For
 386        example, on Ada, the matching algorithm depends on the symbol
 387        name (wild/full/verbatim matching), and on whether we're doing
 388        a normal lookup or a completion match lookup.
 389
 390        This field may be NULL, in which case
 391        default_symbol_name_matcher is used to perform the
 392        matching.  */
 393     symbol_name_matcher_ftype *(*la_get_symbol_name_matcher)
 394       (const lookup_name_info &);
 395
 396     /* Find all symbols in the current program space matching NAME in
 397        DOMAIN, according to this language's rules.
 398
 399        The search is done in BLOCK only.
 400        The caller is responsible for iterating up through superblocks
 401        if desired.
 402
 403        For each one, call CALLBACK with the symbol.  If CALLBACK
 404        returns false, the iteration ends at that point.
 405
 406        This field may not be NULL.  If the language does not need any
 407        special processing here, 'iterate_over_symbols' should be
 408        used as the definition.  */
 409     void (*la_iterate_over_symbols)
 410       (const struct block *block, const lookup_name_info &name,
 411        domain_enum domain,
 412        gdb::function_view<symbol_found_callback_ftype> callback);
 413
 414     /* Hash the given symbol search name.  Use
 415        default_search_name_hash if no special treatment is
 416        required.  */
 417     unsigned int (*la_search_name_hash) (const char *name);
 418
 419     /* Various operations on varobj.  */
 420     const struct lang_varobj_ops *la_varobj_ops;
 421
 422     /* If this language allows compilation from the gdb command line,
 423        this method should be non-NULL.  When called it should return
 424        an instance of struct gcc_context appropriate to the language.
 425        When defined this method must never return NULL; instead it
 426        should throw an exception on failure.  The returned compiler
 427        instance is owned by its caller and must be deallocated by
 428        calling its 'destroy' method.  */
 429
 430     compile_instance *(*la_get_compile_instance) (void);
 431
 432     /* This method must be defined if 'la_get_gcc_context' is defined.
 433        If 'la_get_gcc_context' is not defined, then this method is
 434        ignored.
 435
 436        This takes the user-supplied text and returns a new bit of code
 437        to compile.
 438
 439        INST is the compiler instance being used.
 440        INPUT is the user's input text.
 441        GDBARCH is the architecture to use.
 442        EXPR_BLOCK is the block in which the expression is being
 443        parsed.
 444        EXPR_PC is the PC at which the expression is being parsed.  */
 445
 446     std::string (*la_compute_program) (compile_instance *inst,
 447                                        const char *input,
 448                                        struct gdbarch *gdbarch,
 449                                        const struct block *expr_block,
 450                                        CORE_ADDR expr_pc);
 451
 452     /* Add fields above this point, so the magic number is always last.  */
 453     /* Magic number for compat checking.  */
 454
 455     long la_magic;
 456
 457   };
 458
 459 #define LANG_MAGIC      910823L
 460
 461 /* Pointer to the language_defn for our current language.  This pointer
 462    always points to *some* valid struct; it can be used without checking
 463    it for validity.
 464
 465    The current language affects expression parsing and evaluation
 466    (FIXME: it might be cleaner to make the evaluation-related stuff
 467    separate exp_opcodes for each different set of semantics.  We
 468    should at least think this through more clearly with respect to
 469    what happens if the language is changed between parsing and
 470    evaluation) and printing of things like types and arrays.  It does
 471    *not* affect symbol-reading-- each source file in a symbol-file has
 472    its own language and we should keep track of that regardless of the
 473    language when symbols are read.  If we want some manual setting for
 474    the language of symbol files (e.g. detecting when ".c" files are
 475    C++), it should be a separate setting from the current_language.  */
 476
 477 extern const struct language_defn *current_language;
 478
 479 /* Pointer to the language_defn expected by the user, e.g. the language
 480    of main(), or the language we last mentioned in a message, or C.  */
 481
 482 extern const struct language_defn *expected_language;
 483
 484 /* language_mode ==
 485    language_mode_auto:   current_language automatically set upon selection
 486    of scope (e.g. stack frame)
 487    language_mode_manual: current_language set only by user.  */
 488
 489 extern enum language_mode
 490   {
 491     language_mode_auto, language_mode_manual
 492   }
 493 language_mode;
 494
 495 struct type *language_bool_type (const struct language_defn *l,
 496                                  struct gdbarch *gdbarch);
 497
 498 struct type *language_string_char_type (const struct language_defn *l,
 499                                         struct gdbarch *gdbarch);
 500
 501 /* Look up type NAME in language L, and return its definition for architecture
 502    GDBARCH.  Returns NULL if not found.  */
 503
 504 struct type *language_lookup_primitive_type (const struct language_defn *l,
 505                                              struct gdbarch *gdbarch,
 506                                              const char *name);
 507
 508 /* Wrapper around language_lookup_primitive_type to return the
 509    corresponding symbol.  */
 510
 511 struct symbol *
 512   language_lookup_primitive_type_as_symbol (const struct language_defn *l,
 513                                             struct gdbarch *gdbarch,
 514                                             const char *name);
 515
 516 \f
 517 /* These macros define the behaviour of the expression
 518    evaluator.  */
 519
 520 /* Should we range check values against the domain of their type?  */
 521 #define RANGE_CHECK (range_check != range_check_off)
 522
 523 /* "cast" really means conversion.  */
 524 /* FIXME -- should be a setting in language_defn.  */
 525 #define CAST_IS_CONVERSION(LANG) ((LANG)->la_language == language_c  || \
 526                                   (LANG)->la_language == language_cplus || \
 527                                   (LANG)->la_language == language_objc)
 528
 529 extern void language_info (int);
 530
 531 extern enum language set_language (enum language);
 532 \f
 533
 534 /* This page contains functions that return things that are
 535    specific to languages.  Each of these functions is based on
 536    the current setting of working_lang, which the user sets
 537    with the "set language" command.  */
 538
 539 #define LA_PRINT_TYPE(type,varstring,stream,show,level,flags)           \
 540   (current_language->la_print_type(type,varstring,stream,show,level,flags))
 541
 542 #define LA_PRINT_TYPEDEF(type,new_symbol,stream) \
 543   (current_language->la_print_typedef(type,new_symbol,stream))
 544
 545 #define LA_VALUE_PRINT(val,stream,options) \
 546   (current_language->la_value_print(val,stream,options))
 547
 548 #define LA_PRINT_CHAR(ch, type, stream) \
 549   (current_language->la_printchar(ch, type, stream))
 550 #define LA_PRINT_STRING(stream, elttype, string, length, encoding, force_ellipses, options) \
 551   (current_language->la_printstr(stream, elttype, string, length, \
 552                                  encoding, force_ellipses,options))
 553 #define LA_EMIT_CHAR(ch, type, stream, quoter) \
 554   (current_language->la_emitchar(ch, type, stream, quoter))
 555 #define LA_GET_STRING(value, buffer, length, chartype, encoding) \
 556   (current_language->la_get_string(value, buffer, length, chartype, encoding))
 557
 558 #define LA_PRINT_ARRAY_INDEX(index_value, stream, options) \
 559   (current_language->la_print_array_index(index_value, stream, options))
 560
 561 #define LA_ITERATE_OVER_SYMBOLS(BLOCK, NAME, DOMAIN, CALLBACK) \
 562   (current_language->la_iterate_over_symbols (BLOCK, NAME, DOMAIN, CALLBACK))
 563
 564 /* Test a character to decide whether it can be printed in literal form
 565    or needs to be printed in another representation.  For example,
 566    in C the literal form of the character with octal value 141 is 'a'
 567    and the "other representation" is '\141'.  The "other representation"
 568    is program language dependent.  */
 569
 570 #define PRINT_LITERAL_FORM(c)           \
 571   ((c) >= 0x20                          \
 572    && ((c) < 0x7F || (c) >= 0xA0)       \
 573    && (!sevenbit_strings || (c) < 0x80))
 574
 575 /* Type predicates */
 576
 577 extern int pointer_type (struct type *);
 578
 579 /* Error messages */
 580
 581 extern void range_error (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
 582
 583 /* Data:  Does this value represent "truth" to the current language?  */
 584
 585 extern int value_true (struct value *);
 586
 587 /* Misc:  The string representing a particular enum language.  */
 588
 589 extern enum language language_enum (const char *str);
 590
 591 extern const struct language_defn *language_def (enum language);
 592
 593 extern const char *language_str (enum language);
 594
 595 /* Check for a language-specific trampoline.  */
 596
 597 extern CORE_ADDR skip_language_trampoline (struct frame_info *, CORE_ADDR pc);
 598
 599 /* Return demangled language symbol, or NULL.  */
 600 extern char *language_demangle (const struct language_defn *current_language,
 601                                 const char *mangled, int options);
 602
 603 /* A wrapper for la_sniff_from_mangled_name.  The arguments and result
 604    are as for the method.  */
 605
 606 extern int language_sniff_from_mangled_name (const struct language_defn *lang,
 607                                              const char *mangled,
 608                                              char **demangled);
 609
 610 /* Return class name from physname, or NULL.  */
 611 extern char *language_class_name_from_physname (const struct language_defn *,
 612                                                 const char *physname);
 613
 614 /* Splitting strings into words.  */
 615 extern const char *default_word_break_characters (void);
 616
 617 /* Print the index of an array element using the C99 syntax.  */
 618 extern void default_print_array_index (struct value *index_value,
 619                                        struct ui_file *stream,
 620                                        const struct value_print_options *options);
 621
 622 /* Return non-zero if TYPE should be passed (and returned) by
 623    reference at the language level.  */
 624 int language_pass_by_reference (struct type *type);
 625
 626 /* Return zero; by default, types are passed by value at the language
 627    level.  The target ABI may pass or return some structs by reference
 628    independent of this.  */
 629 int default_pass_by_reference (struct type *type);
 630
 631 /* The default implementation of la_print_typedef.  */
 632 void default_print_typedef (struct type *type, struct symbol *new_symbol,
 633                             struct ui_file *stream);
 634
 635 void default_get_string (struct value *value,
 636                          gdb::unique_xmalloc_ptr<gdb_byte> *buffer,
 637                          int *length, struct type **char_type,
 638                          const char **charset);
 639
 640 /* Default name hashing function.  */
 641
 642 /* Produce an unsigned hash value from SEARCH_NAME that is consistent
 643    with strcmp_iw, strcmp, and, at least on Ada symbols, wild_match.
 644    That is, two identifiers equivalent according to any of those three
 645    comparison operators hash to the same value.  */
 646 extern unsigned int default_search_name_hash (const char *search_name);
 647
 648 void c_get_string (struct value *value,
 649                    gdb::unique_xmalloc_ptr<gdb_byte> *buffer,
 650                    int *length, struct type **char_type,
 651                    const char **charset);
 652
 653 /* The default implementation of la_symbol_name_matcher.  Matches with
 654    strncmp_iw.  */
 655 extern bool default_symbol_name_matcher
 656   (const char *symbol_search_name,
 657    const lookup_name_info &lookup_name,
 658    completion_match_result *comp_match_res);
 659
 660 /* Get LANG's symbol_name_matcher method for LOOKUP_NAME.  Returns
 661    default_symbol_name_matcher if not set.  LANG is used as a hint;
 662    the function may ignore it depending on the current language and
 663    LOOKUP_NAME.  Specifically, if the current language is Ada, this
 664    may return an Ada matcher regardless of LANG.  */
 665 symbol_name_matcher_ftype *get_symbol_name_matcher
 666   (const language_defn *lang, const lookup_name_info &lookup_name);
 667
 668 /* The languages supported by GDB.  */
 669
 670 extern const struct language_defn auto_language_defn;
 671 extern const struct language_defn unknown_language_defn;
 672 extern const struct language_defn minimal_language_defn;
 673
 674 extern const struct language_defn ada_language_defn;
 675 extern const struct language_defn asm_language_defn;
 676 extern const struct language_defn c_language_defn;
 677 extern const struct language_defn cplus_language_defn;
 678 extern const struct language_defn d_language_defn;
 679 extern const struct language_defn f_language_defn;
 680 extern const struct language_defn go_language_defn;
 681 extern const struct language_defn m2_language_defn;
 682 extern const struct language_defn objc_language_defn;
 683 extern const struct language_defn opencl_language_defn;
 684 extern const struct language_defn pascal_language_defn;
 685 extern const struct language_defn rust_language_defn;
 686
 687 /* Save the current language and restore it upon destruction.  */
 688
 689 class scoped_restore_current_language
 690 {
 691 public:
 692
 693   explicit scoped_restore_current_language ()
 694     : m_lang (current_language->la_language)
 695   {
 696   }
 697
 698   ~scoped_restore_current_language ()
 699   {
 700     set_language (m_lang);
 701   }
 702
 703   scoped_restore_current_language (const scoped_restore_current_language &)
 704       = delete;
 705   scoped_restore_current_language &operator=
 706       (const scoped_restore_current_language &) = delete;
 707
 708 private:
 709
 710   enum language m_lang;
 711 };
 712
 713 /* If language_mode is language_mode_auto,
 714    then switch current language to the language of SYM
 715    and restore current language upon destruction.
 716
 717    Else do nothing.  */
 718
 719 class scoped_switch_to_sym_language_if_auto
 720 {
 721 public:
 722
 723   explicit scoped_switch_to_sym_language_if_auto (const struct symbol *sym)
 724   {
 725     if (language_mode == language_mode_auto)
 726       {
 727         m_lang = current_language->la_language;
 728         m_switched = true;
 729         set_language (SYMBOL_LANGUAGE (sym));
 730       }
 731     else
 732       {
 733         m_switched = false;
 734         /* Assign to m_lang to silence a GCC warning.  See
 735            https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80635.  */
 736         m_lang = language_unknown;
 737       }
 738   }
 739
 740   ~scoped_switch_to_sym_language_if_auto ()
 741   {
 742     if (m_switched)
 743       set_language (m_lang);
 744   }
 745
 746   DISABLE_COPY_AND_ASSIGN (scoped_switch_to_sym_language_if_auto);
 747
 748 private:
 749   bool m_switched;
 750   enum language m_lang;
 751 };
 752
 753 #endif /* defined (LANGUAGE_H) */