gdb/language.h

   1 /* Source-language-related definitions for GDB.
   2
   3    Copyright (C) 1991-2020 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 "gdbsupport/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 class innermost_block_tracker;
  42
  43 #define MAX_FORTRAN_DIMS  7     /* Maximum number of F77 array dims.  */
  44
  45 /* range_mode ==
  46    range_mode_auto:   range_check set automatically to default of language.
  47    range_mode_manual: range_check set manually by user.  */
  48
  49 extern enum range_mode
  50   {
  51     range_mode_auto, range_mode_manual
  52   }
  53 range_mode;
  54
  55 /* range_check ==
  56    range_check_on:    Ranges are checked in GDB expressions, producing errors.
  57    range_check_warn:  Ranges are checked, producing warnings.
  58    range_check_off:   Ranges are not checked in GDB expressions.  */
  59
  60 extern enum range_check
  61   {
  62     range_check_off, range_check_warn, range_check_on
  63   }
  64 range_check;
  65
  66 /* case_mode ==
  67    case_mode_auto:   case_sensitivity set upon selection of scope.
  68    case_mode_manual: case_sensitivity set only by user.  */
  69
  70 extern enum case_mode
  71   {
  72     case_mode_auto, case_mode_manual
  73   }
  74 case_mode;
  75
  76 /* array_ordering ==
  77    array_row_major:     Arrays are in row major order.
  78    array_column_major:  Arrays are in column major order.  */
  79
  80 extern enum array_ordering
  81   {
  82     array_row_major, array_column_major
  83   }
  84 array_ordering;
  85
  86
  87 /* case_sensitivity ==
  88    case_sensitive_on:   Case sensitivity in name matching is used.
  89    case_sensitive_off:  Case sensitivity in name matching is not used.  */
  90
  91 extern enum case_sensitivity
  92   {
  93     case_sensitive_on, case_sensitive_off
  94   }
  95 case_sensitivity;
  96
  97
  98 /* macro_expansion ==
  99    macro_expansion_no:  No macro expansion is available.
 100    macro_expansion_c:   C-like macro expansion is available.  */
 101
 102 enum macro_expansion
 103   {
 104     macro_expansion_no, macro_expansion_c
 105   };
 106
 107 \f
 108 /* Per architecture (OS/ABI) language information.  */
 109
 110 struct language_arch_info
 111 {
 112   /* Its primitive types.  This is a vector ended by a NULL pointer.
 113      These types can be specified by name in parsing types in
 114      expressions, regardless of whether the program being debugged
 115      actually defines such a type.  */
 116   struct type **primitive_type_vector;
 117
 118   /* Symbol wrappers around primitive_type_vector, so that the symbol lookup
 119      machinery can return them.  */
 120   struct symbol **primitive_type_symbols;
 121
 122   /* Type of elements of strings.  */
 123   struct type *string_char_type;
 124
 125   /* Symbol name of type to use as boolean type, if defined.  */
 126   const char *bool_type_symbol;
 127   /* Otherwise, this is the default boolean builtin type.  */
 128   struct type *bool_type_default;
 129 };
 130
 131 /* In a language (particularly C++) a function argument of an aggregate
 132    type (i.e.  class/struct/union) may be implicitly passed by reference
 133    even though it is declared a call-by-value argument in the source.
 134    The struct below puts together necessary information for GDB to be
 135    able to detect and carry out pass-by-reference semantics for a
 136    particular type.  This type is referred as T in the inlined comments
 137    below.
 138
 139    The default values of the fields are chosen to give correct semantics
 140    for primitive types and for simple aggregate types, such as
 141
 142    class T {
 143      int x;
 144    };  */
 145
 146 struct language_pass_by_ref_info
 147 {
 148   /* True if an argument of type T can be passed to a function by value
 149      (i.e.  not through an implicit reference).  False, otherwise.  */
 150   bool trivially_copyable = true;
 151
 152   /* True if a copy of a value of type T can be initialized by
 153      memcpy'ing the value bit-by-bit.  False, otherwise.
 154      E.g.  If T has a user-defined copy ctor, this should be false.  */
 155   bool trivially_copy_constructible = true;
 156
 157   /* True if a value of type T can be destructed simply by reclaiming
 158      the memory area occupied by the value.  False, otherwise.
 159      E.g.  If T has a user-defined destructor, this should be false.  */
 160   bool trivially_destructible = true;
 161
 162   /* True if it is allowed to create a copy of a value of type T.
 163      False, otherwise.
 164      E.g.  If T has a deleted copy ctor, this should be false.  */
 165   bool copy_constructible = true;
 166
 167   /* True if a value of type T can be destructed.  False, otherwise.
 168      E.g.  If T has a deleted destructor, this should be false.  */
 169   bool destructible = true;
 170 };
 171
 172 /* Structure tying together assorted information about a language.  */
 173
 174 struct language_defn
 175   {
 176     /* Name of the language.  */
 177
 178     const char *la_name;
 179
 180     /* Natural or official name of the language.  */
 181
 182     const char *la_natural_name;
 183
 184     /* its symtab language-enum (defs.h).  */
 185
 186     enum language la_language;
 187
 188     /* Default range checking.  */
 189
 190     enum range_check la_range_check;
 191
 192     /* Default case sensitivity.  */
 193     enum case_sensitivity la_case_sensitivity;
 194
 195     /* Multi-dimensional array ordering.  */
 196     enum array_ordering la_array_ordering;
 197
 198     /* Style of macro expansion, if any, supported by this language.  */
 199     enum macro_expansion la_macro_expansion;
 200
 201     /* A NULL-terminated array of file extensions for this language.
 202        The extension must include the ".", like ".c".  If this
 203        language doesn't need to provide any filename extensions, this
 204        may be NULL.  */
 205
 206     const char *const *la_filename_extensions;
 207
 208     /* Definitions related to expression printing, prefixifying, and
 209        dumping.  */
 210
 211     const struct exp_descriptor *la_exp_desc;
 212
 213     /* Parser function.  */
 214
 215     int (*la_parser) (struct parser_state *);
 216
 217     /* Given an expression *EXPP created by prefixifying the result of
 218        la_parser, perform any remaining processing necessary to complete
 219        its translation.  *EXPP may change; la_post_parser is responsible
 220        for releasing its previous contents, if necessary.  If
 221        VOID_CONTEXT_P, then no value is expected from the expression.
 222        If COMPLETING is non-zero, then the expression has been parsed
 223        for completion, not evaluation.  */
 224
 225     void (*la_post_parser) (expression_up *expp, int void_context_p,
 226                             int completing, innermost_block_tracker *tracker);
 227
 228     void (*la_printchar) (int ch, struct type *chtype,
 229                           struct ui_file * stream);
 230
 231     void (*la_printstr) (struct ui_file * stream, struct type *elttype,
 232                          const gdb_byte *string, unsigned int length,
 233                          const char *encoding, int force_ellipses,
 234                          const struct value_print_options *);
 235
 236     void (*la_emitchar) (int ch, struct type *chtype,
 237                          struct ui_file * stream, int quoter);
 238
 239     /* Print a type using syntax appropriate for this language.  */
 240
 241     void (*la_print_type) (struct type *, const char *, struct ui_file *, int,
 242                            int, const struct type_print_options *);
 243
 244     /* Print a typedef using syntax appropriate for this language.
 245        TYPE is the underlying type.  NEW_SYMBOL is the symbol naming
 246        the type.  STREAM is the output stream on which to print.  */
 247
 248     void (*la_print_typedef) (struct type *type, struct symbol *new_symbol,
 249                               struct ui_file *stream);
 250
 251     /* Print a value using syntax appropriate for this language.
 252
 253        TYPE is the type of the sub-object to be printed.
 254
 255        EMBEDDED_OFFSET is the offset into the outermost object of the
 256        sub-object represented by TYPE.  This is the object which this
 257        call should print.  Note that the enclosing type is not
 258        available.
 259
 260        ADDRESS is the address in the inferior of the enclosing object.
 261
 262        STREAM is the stream on which the value is to be printed.
 263
 264        RECURSE is the recursion depth.  It is zero-based.
 265
 266        OPTIONS are the formatting options to be used when
 267        printing.  */
 268
 269     void (*la_val_print) (struct type *type,
 270                           int embedded_offset, CORE_ADDR address,
 271                           struct ui_file *stream, int recurse,
 272                           struct value *val,
 273                           const struct value_print_options *options);
 274
 275     /* Print a value using syntax appropriate for this language.
 276        RECURSE is the recursion depth.  It is zero-based.  */
 277
 278     void (*la_value_print_inner) (struct value *, struct ui_file *,
 279                                   int recurse,
 280                                   const struct value_print_options *);
 281
 282     /* Print a top-level value using syntax appropriate for this language.  */
 283
 284     void (*la_value_print) (struct value *, struct ui_file *,
 285                             const struct value_print_options *);
 286
 287     /* Given a symbol VAR, the corresponding block VAR_BLOCK (if any) and a
 288        stack frame id FRAME, read the value of the variable and return (pointer
 289        to a) struct value containing the value.
 290
 291        VAR_BLOCK is needed if there's a possibility for VAR to be outside
 292        FRAME.  This is what happens if FRAME correspond to a nested function
 293        and VAR is defined in the outer function.  If callers know that VAR is
 294        located in FRAME or is global/static, NULL can be passed as VAR_BLOCK.
 295
 296        Throw an error if the variable cannot be found.  */
 297
 298     struct value *(*la_read_var_value) (struct symbol *var,
 299                                         const struct block *var_block,
 300                                         struct frame_info *frame);
 301
 302     /* PC is possibly an unknown languages trampoline.
 303        If that PC falls in a trampoline belonging to this language,
 304        return the address of the first pc in the real function, or 0
 305        if it isn't a language tramp for this language.  */
 306     CORE_ADDR (*skip_trampoline) (struct frame_info *, CORE_ADDR);
 307
 308     /* Now come some hooks for lookup_symbol.  */
 309
 310     /* If this is non-NULL, specifies the name that of the implicit
 311        local variable that refers to the current object instance.  */
 312
 313     const char *la_name_of_this;
 314
 315     /* True if the symbols names should be stored in GDB's data structures
 316        for minimal/partial/full symbols using their linkage (aka mangled)
 317        form; false if the symbol names should be demangled first.
 318
 319        Most languages implement symbol lookup by comparing the demangled
 320        names, in which case it is advantageous to store that information
 321        already demangled, and so would set this field to false.
 322
 323        On the other hand, some languages have opted for doing symbol
 324        lookups by comparing mangled names instead, for reasons usually
 325        specific to the language.  Those languages should set this field
 326        to true.
 327
 328        And finally, other languages such as C or Asm do not have
 329        the concept of mangled vs demangled name, so those languages
 330        should set this field to true as well, to prevent any accidental
 331        demangling through an unrelated language's demangler.  */
 332
 333     const bool la_store_sym_names_in_linkage_form_p;
 334
 335     /* This is a function that lookup_symbol will call when it gets to
 336        the part of symbol lookup where C looks up static and global
 337        variables.  */
 338
 339     struct block_symbol (*la_lookup_symbol_nonlocal)
 340       (const struct language_defn *,
 341        const char *,
 342        const struct block *,
 343        const domain_enum);
 344
 345     /* Find the definition of the type with the given name.  */
 346     struct type *(*la_lookup_transparent_type) (const char *);
 347
 348     /* Return demangled language symbol, or NULL.  */
 349     char *(*la_demangle) (const char *mangled, int options);
 350
 351     /* Demangle a symbol according to this language's rules.  Unlike
 352        la_demangle, this does not take any options.
 353
 354        *DEMANGLED will be set by this function.
 355
 356        If this function returns 0, then *DEMANGLED must always be set
 357        to NULL.
 358
 359        If this function returns 1, the implementation may set this to
 360        a xmalloc'd string holding the demangled form.  However, it is
 361        not required to.  The string, if any, is owned by the caller.
 362
 363        The resulting string should be of the form that will be
 364        installed into a symbol.  */
 365     int (*la_sniff_from_mangled_name) (const char *mangled, char **demangled);
 366
 367     /* Return class name of a mangled method name or NULL.  */
 368     char *(*la_class_name_from_physname) (const char *physname);
 369
 370     /* Table for printing expressions.  */
 371
 372     const struct op_print *la_op_print_tab;
 373
 374     /* Zero if the language has first-class arrays.  True if there are no
 375        array values, and array objects decay to pointers, as in C.  */
 376
 377     char c_style_arrays;
 378
 379     /* Index to use for extracting the first element of a string.  */
 380     char string_lower_bound;
 381
 382     /* The list of characters forming word boundaries.  */
 383     const char *(*la_word_break_characters) (void);
 384
 385     /* Add to the completion tracker all symbols which are possible
 386        completions for TEXT.  WORD is the entire command on which the
 387        completion is being made.  If CODE is TYPE_CODE_UNDEF, then all
 388        symbols should be examined; otherwise, only STRUCT_DOMAIN
 389        symbols whose type has a code of CODE should be matched.  */
 390     void (*la_collect_symbol_completion_matches)
 391       (completion_tracker &tracker,
 392        complete_symbol_mode mode,
 393        symbol_name_match_type match_type,
 394        const char *text,
 395        const char *word,
 396        enum type_code code);
 397
 398     /* The per-architecture (OS/ABI) language information.  */
 399     void (*la_language_arch_info) (struct gdbarch *,
 400                                    struct language_arch_info *);
 401
 402     /* Print the index of an element of an array.  */
 403     void (*la_print_array_index) (struct value *index_value,
 404                                   struct ui_file *stream,
 405                                   const struct value_print_options *options);
 406
 407     /* Return information about whether TYPE should be passed
 408        (and returned) by reference at the language level.  */
 409     struct language_pass_by_ref_info (*la_pass_by_reference)
 410       (struct type *type);
 411
 412     /* Return an expression that can be used for a location
 413        watchpoint.  TYPE is a pointer type that points to the memory
 414        to watch, and ADDR is the address of the watched memory.  */
 415     gdb::unique_xmalloc_ptr<char> (*la_watch_location_expression)
 416          (struct type *type, CORE_ADDR addr);
 417
 418     /* Return a pointer to the function that should be used to match a
 419        symbol name against LOOKUP_NAME, according to this language's
 420        rules.  The matching algorithm depends on LOOKUP_NAME.  For
 421        example, on Ada, the matching algorithm depends on the symbol
 422        name (wild/full/verbatim matching), and on whether we're doing
 423        a normal lookup or a completion match lookup.
 424
 425        This field may be NULL, in which case
 426        default_symbol_name_matcher is used to perform the
 427        matching.  */
 428     symbol_name_matcher_ftype *(*la_get_symbol_name_matcher)
 429       (const lookup_name_info &);
 430
 431     /* Find all symbols in the current program space matching NAME in
 432        DOMAIN, according to this language's rules.
 433
 434        The search is done in BLOCK only.
 435        The caller is responsible for iterating up through superblocks
 436        if desired.
 437
 438        For each one, call CALLBACK with the symbol.  If CALLBACK
 439        returns false, the iteration ends at that point.
 440
 441        This field may not be NULL.  If the language does not need any
 442        special processing here, 'iterate_over_symbols' should be
 443        used as the definition.  */
 444     bool (*la_iterate_over_symbols)
 445       (const struct block *block, const lookup_name_info &name,
 446        domain_enum domain,
 447        gdb::function_view<symbol_found_callback_ftype> callback);
 448
 449     /* Hash the given symbol search name.  Use
 450        default_search_name_hash if no special treatment is
 451        required.  */
 452     unsigned int (*la_search_name_hash) (const char *name);
 453
 454     /* Various operations on varobj.  */
 455     const struct lang_varobj_ops *la_varobj_ops;
 456
 457     /* If this language allows compilation from the gdb command line,
 458        this method should be non-NULL.  When called it should return
 459        an instance of struct gcc_context appropriate to the language.
 460        When defined this method must never return NULL; instead it
 461        should throw an exception on failure.  The returned compiler
 462        instance is owned by its caller and must be deallocated by
 463        calling its 'destroy' method.  */
 464
 465     compile_instance *(*la_get_compile_instance) (void);
 466
 467     /* This method must be defined if 'la_get_gcc_context' is defined.
 468        If 'la_get_gcc_context' is not defined, then this method is
 469        ignored.
 470
 471        This takes the user-supplied text and returns a new bit of code
 472        to compile.
 473
 474        INST is the compiler instance being used.
 475        INPUT is the user's input text.
 476        GDBARCH is the architecture to use.
 477        EXPR_BLOCK is the block in which the expression is being
 478        parsed.
 479        EXPR_PC is the PC at which the expression is being parsed.  */
 480
 481     std::string (*la_compute_program) (compile_instance *inst,
 482                                        const char *input,
 483                                        struct gdbarch *gdbarch,
 484                                        const struct block *expr_block,
 485                                        CORE_ADDR expr_pc);
 486
 487     /* Return true if TYPE is a string type.  */
 488     bool (*la_is_string_type_p) (struct type *type);
 489
 490     /* This string is used by the 'set print max-depth' setting.  When GDB
 491        replaces a struct or union (during value printing) that is "too
 492        deep" this string is displayed instead.  */
 493     const char *la_struct_too_deep_ellipsis;
 494
 495   };
 496
 497 /* Pointer to the language_defn for our current language.  This pointer
 498    always points to *some* valid struct; it can be used without checking
 499    it for validity.
 500
 501    The current language affects expression parsing and evaluation
 502    (FIXME: it might be cleaner to make the evaluation-related stuff
 503    separate exp_opcodes for each different set of semantics.  We
 504    should at least think this through more clearly with respect to
 505    what happens if the language is changed between parsing and
 506    evaluation) and printing of things like types and arrays.  It does
 507    *not* affect symbol-reading-- each source file in a symbol-file has
 508    its own language and we should keep track of that regardless of the
 509    language when symbols are read.  If we want some manual setting for
 510    the language of symbol files (e.g. detecting when ".c" files are
 511    C++), it should be a separate setting from the current_language.  */
 512
 513 extern const struct language_defn *current_language;
 514
 515 /* Pointer to the language_defn expected by the user, e.g. the language
 516    of main(), or the language we last mentioned in a message, or C.  */
 517
 518 extern const struct language_defn *expected_language;
 519
 520 /* Warning issued when current_language and the language of the current
 521    frame do not match.  */
 522
 523 extern const char lang_frame_mismatch_warn[];
 524
 525 /* language_mode ==
 526    language_mode_auto:   current_language automatically set upon selection
 527    of scope (e.g. stack frame)
 528    language_mode_manual: current_language set only by user.  */
 529
 530 extern enum language_mode
 531   {
 532     language_mode_auto, language_mode_manual
 533   }
 534 language_mode;
 535
 536 struct type *language_bool_type (const struct language_defn *l,
 537                                  struct gdbarch *gdbarch);
 538
 539 struct type *language_string_char_type (const struct language_defn *l,
 540                                         struct gdbarch *gdbarch);
 541
 542 /* Look up type NAME in language L, and return its definition for architecture
 543    GDBARCH.  Returns NULL if not found.  */
 544
 545 struct type *language_lookup_primitive_type (const struct language_defn *l,
 546                                              struct gdbarch *gdbarch,
 547                                              const char *name);
 548
 549 /* Wrapper around language_lookup_primitive_type to return the
 550    corresponding symbol.  */
 551
 552 struct symbol *
 553   language_lookup_primitive_type_as_symbol (const struct language_defn *l,
 554                                             struct gdbarch *gdbarch,
 555                                             const char *name);
 556
 557 \f
 558 /* These macros define the behaviour of the expression
 559    evaluator.  */
 560
 561 /* Should we range check values against the domain of their type?  */
 562 #define RANGE_CHECK (range_check != range_check_off)
 563
 564 /* "cast" really means conversion.  */
 565 /* FIXME -- should be a setting in language_defn.  */
 566 #define CAST_IS_CONVERSION(LANG) ((LANG)->la_language == language_c  || \
 567                                   (LANG)->la_language == language_cplus || \
 568                                   (LANG)->la_language == language_objc)
 569
 570 extern void language_info (int);
 571
 572 extern enum language set_language (enum language);
 573 \f
 574
 575 /* This page contains functions that return things that are
 576    specific to languages.  Each of these functions is based on
 577    the current setting of working_lang, which the user sets
 578    with the "set language" command.  */
 579
 580 #define LA_PRINT_TYPE(type,varstring,stream,show,level,flags)           \
 581   (current_language->la_print_type(type,varstring,stream,show,level,flags))
 582
 583 #define LA_PRINT_TYPEDEF(type,new_symbol,stream) \
 584   (current_language->la_print_typedef(type,new_symbol,stream))
 585
 586 #define LA_VALUE_PRINT(val,stream,options) \
 587   (current_language->la_value_print(val,stream,options))
 588
 589 #define LA_PRINT_CHAR(ch, type, stream) \
 590   (current_language->la_printchar(ch, type, stream))
 591 #define LA_PRINT_STRING(stream, elttype, string, length, encoding, force_ellipses, options) \
 592   (current_language->la_printstr(stream, elttype, string, length, \
 593                                  encoding, force_ellipses,options))
 594 #define LA_EMIT_CHAR(ch, type, stream, quoter) \
 595   (current_language->la_emitchar(ch, type, stream, quoter))
 596
 597 #define LA_PRINT_ARRAY_INDEX(index_value, stream, options) \
 598   (current_language->la_print_array_index(index_value, stream, options))
 599
 600 #define LA_ITERATE_OVER_SYMBOLS(BLOCK, NAME, DOMAIN, CALLBACK) \
 601   (current_language->la_iterate_over_symbols (BLOCK, NAME, DOMAIN, CALLBACK))
 602
 603 /* Test a character to decide whether it can be printed in literal form
 604    or needs to be printed in another representation.  For example,
 605    in C the literal form of the character with octal value 141 is 'a'
 606    and the "other representation" is '\141'.  The "other representation"
 607    is program language dependent.  */
 608
 609 #define PRINT_LITERAL_FORM(c)           \
 610   ((c) >= 0x20                          \
 611    && ((c) < 0x7F || (c) >= 0xA0)       \
 612    && (!sevenbit_strings || (c) < 0x80))
 613
 614 /* Type predicates */
 615
 616 extern int pointer_type (struct type *);
 617
 618 /* Return true if TYPE is a string type, otherwise return false.  This
 619    default implementation only detects TYPE_CODE_STRING.  */
 620 extern bool default_is_string_type_p (struct type *type);
 621
 622 /* Error messages */
 623
 624 extern void range_error (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
 625
 626 /* Data:  Does this value represent "truth" to the current language?  */
 627
 628 extern int value_true (struct value *);
 629
 630 /* Misc:  The string representing a particular enum language.  */
 631
 632 extern enum language language_enum (const char *str);
 633
 634 extern const struct language_defn *language_def (enum language);
 635
 636 extern const char *language_str (enum language);
 637
 638 /* Check for a language-specific trampoline.  */
 639
 640 extern CORE_ADDR skip_language_trampoline (struct frame_info *, CORE_ADDR pc);
 641
 642 /* Return demangled language symbol, or NULL.  */
 643 extern char *language_demangle (const struct language_defn *current_language,
 644                                 const char *mangled, int options);
 645
 646 /* A wrapper for la_sniff_from_mangled_name.  The arguments and result
 647    are as for the method.  */
 648
 649 extern int language_sniff_from_mangled_name (const struct language_defn *lang,
 650                                              const char *mangled,
 651                                              char **demangled);
 652
 653 /* Return class name from physname, or NULL.  */
 654 extern char *language_class_name_from_physname (const struct language_defn *,
 655                                                 const char *physname);
 656
 657 /* Splitting strings into words.  */
 658 extern const char *default_word_break_characters (void);
 659
 660 /* Print the index of an array element using the C99 syntax.  */
 661 extern void default_print_array_index (struct value *index_value,
 662                                        struct ui_file *stream,
 663                                        const struct value_print_options *options);
 664
 665 /* Return information about whether TYPE should be passed
 666    (and returned) by reference at the language level.  */
 667 struct language_pass_by_ref_info language_pass_by_reference (struct type *type);
 668
 669 /* Return a default struct that provides pass-by-reference information
 670    about the given TYPE.  Languages should update the default values
 671    as appropriate.  */
 672 struct language_pass_by_ref_info default_pass_by_reference (struct type *type);
 673
 674 /* The default implementation of la_print_typedef.  */
 675 void default_print_typedef (struct type *type, struct symbol *new_symbol,
 676                             struct ui_file *stream);
 677
 678 /* Default name hashing function.  */
 679
 680 /* Produce an unsigned hash value from SEARCH_NAME that is consistent
 681    with strcmp_iw, strcmp, and, at least on Ada symbols, wild_match.
 682    That is, two identifiers equivalent according to any of those three
 683    comparison operators hash to the same value.  */
 684 extern unsigned int default_search_name_hash (const char *search_name);
 685
 686 void c_get_string (struct value *value,
 687                    gdb::unique_xmalloc_ptr<gdb_byte> *buffer,
 688                    int *length, struct type **char_type,
 689                    const char **charset);
 690
 691 /* The default implementation of la_symbol_name_matcher.  Matches with
 692    strncmp_iw.  */
 693 extern bool default_symbol_name_matcher
 694   (const char *symbol_search_name,
 695    const lookup_name_info &lookup_name,
 696    completion_match_result *comp_match_res);
 697
 698 /* Get LANG's symbol_name_matcher method for LOOKUP_NAME.  Returns
 699    default_symbol_name_matcher if not set.  LANG is used as a hint;
 700    the function may ignore it depending on the current language and
 701    LOOKUP_NAME.  Specifically, if the current language is Ada, this
 702    may return an Ada matcher regardless of LANG.  */
 703 symbol_name_matcher_ftype *get_symbol_name_matcher
 704   (const language_defn *lang, const lookup_name_info &lookup_name);
 705
 706 /* The languages supported by GDB.  */
 707
 708 extern const struct language_defn auto_language_defn;
 709 extern const struct language_defn unknown_language_defn;
 710 extern const struct language_defn minimal_language_defn;
 711
 712 extern const struct language_defn ada_language_defn;
 713 extern const struct language_defn asm_language_defn;
 714 extern const struct language_defn c_language_defn;
 715 extern const struct language_defn cplus_language_defn;
 716 extern const struct language_defn d_language_defn;
 717 extern const struct language_defn f_language_defn;
 718 extern const struct language_defn go_language_defn;
 719 extern const struct language_defn m2_language_defn;
 720 extern const struct language_defn objc_language_defn;
 721 extern const struct language_defn opencl_language_defn;
 722 extern const struct language_defn pascal_language_defn;
 723 extern const struct language_defn rust_language_defn;
 724
 725 /* Save the current language and restore it upon destruction.  */
 726
 727 class scoped_restore_current_language
 728 {
 729 public:
 730
 731   explicit scoped_restore_current_language ()
 732     : m_lang (current_language->la_language)
 733   {
 734   }
 735
 736   ~scoped_restore_current_language ()
 737   {
 738     set_language (m_lang);
 739   }
 740
 741   scoped_restore_current_language (const scoped_restore_current_language &)
 742       = delete;
 743   scoped_restore_current_language &operator=
 744       (const scoped_restore_current_language &) = delete;
 745
 746 private:
 747
 748   enum language m_lang;
 749 };
 750
 751 /* If language_mode is language_mode_auto,
 752    then switch current language to the language of SYM
 753    and restore current language upon destruction.
 754
 755    Else do nothing.  */
 756
 757 class scoped_switch_to_sym_language_if_auto
 758 {
 759 public:
 760
 761   explicit scoped_switch_to_sym_language_if_auto (const struct symbol *sym)
 762   {
 763     if (language_mode == language_mode_auto)
 764       {
 765         m_lang = current_language->la_language;
 766         m_switched = true;
 767         set_language (sym->language ());
 768       }
 769     else
 770       {
 771         m_switched = false;
 772         /* Assign to m_lang to silence a GCC warning.  See
 773            https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80635.  */
 774         m_lang = language_unknown;
 775       }
 776   }
 777
 778   ~scoped_switch_to_sym_language_if_auto ()
 779   {
 780     if (m_switched)
 781       set_language (m_lang);
 782   }
 783
 784   DISABLE_COPY_AND_ASSIGN (scoped_switch_to_sym_language_if_auto);
 785
 786 private:
 787   bool m_switched;
 788   enum language m_lang;
 789 };
 790
 791 #endif /* defined (LANGUAGE_H) */