gdb/language.h

   1 /* Source-language-related definitions for GDB.
   2
   3    Copyright (C) 1991-2015 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
  28 /* Forward decls for prototypes.  */
  29 struct value;
  30 struct objfile;
  31 struct frame_info;
  32 struct expression;
  33 struct ui_file;
  34 struct value_print_options;
  35 struct type_print_options;
  36 struct lang_varobj_ops;
  37 struct parser_state;
  38 struct compile_instance;
  39
  40 #define MAX_FORTRAN_DIMS  7     /* Maximum number of F77 array dims.  */
  41
  42 /* range_mode ==
  43    range_mode_auto:   range_check set automatically to default of language.
  44    range_mode_manual: range_check set manually by user.  */
  45
  46 extern enum range_mode
  47   {
  48     range_mode_auto, range_mode_manual
  49   }
  50 range_mode;
  51
  52 /* range_check ==
  53    range_check_on:    Ranges are checked in GDB expressions, producing errors.
  54    range_check_warn:  Ranges are checked, producing warnings.
  55    range_check_off:   Ranges are not checked in GDB expressions.  */
  56
  57 extern enum range_check
  58   {
  59     range_check_off, range_check_warn, range_check_on
  60   }
  61 range_check;
  62
  63 /* case_mode ==
  64    case_mode_auto:   case_sensitivity set upon selection of scope.
  65    case_mode_manual: case_sensitivity set only by user.  */
  66
  67 extern enum case_mode
  68   {
  69     case_mode_auto, case_mode_manual
  70   }
  71 case_mode;
  72
  73 /* array_ordering ==
  74    array_row_major:     Arrays are in row major order.
  75    array_column_major:  Arrays are in column major order.  */
  76
  77 extern enum array_ordering
  78   {
  79     array_row_major, array_column_major
  80   }
  81 array_ordering;
  82
  83
  84 /* case_sensitivity ==
  85    case_sensitive_on:   Case sensitivity in name matching is used.
  86    case_sensitive_off:  Case sensitivity in name matching is not used.  */
  87
  88 extern enum case_sensitivity
  89   {
  90     case_sensitive_on, case_sensitive_off
  91   }
  92 case_sensitivity;
  93
  94
  95 /* macro_expansion ==
  96    macro_expansion_no:  No macro expansion is available.
  97    macro_expansion_c:   C-like macro expansion is available.  */
  98
  99 enum macro_expansion
 100   {
 101     macro_expansion_no, macro_expansion_c
 102   };
 103
 104 \f
 105 /* Per architecture (OS/ABI) language information.  */
 106
 107 struct language_arch_info
 108 {
 109   /* Its primitive types.  This is a vector ended by a NULL pointer.
 110      These types can be specified by name in parsing types in
 111      expressions, regardless of whether the program being debugged
 112      actually defines such a type.  */
 113   struct type **primitive_type_vector;
 114
 115   /* Symbol wrappers around primitive_type_vector, so that the symbol lookup
 116      machinery can return them.  */
 117   struct symbol **primitive_type_symbols;
 118
 119   /* Type of elements of strings.  */
 120   struct type *string_char_type;
 121
 122   /* Symbol name of type to use as boolean type, if defined.  */
 123   const char *bool_type_symbol;
 124   /* Otherwise, this is the default boolean builtin type.  */
 125   struct type *bool_type_default;
 126 };
 127
 128 /* A pointer to a function expected to return nonzero if
 129    SYMBOL_SEARCH_NAME matches the given LOOKUP_NAME.
 130
 131    SYMBOL_SEARCH_NAME should be a symbol's "search" name.
 132    LOOKUP_NAME should be the name of an entity after it has been
 133    transformed for lookup.  */
 134
 135 typedef int (*symbol_name_cmp_ftype) (const char *symbol_search_name,
 136                                           const char *lookup_name);
 137
 138 /* Structure tying together assorted information about a language.  */
 139
 140 struct language_defn
 141   {
 142     /* Name of the language.  */
 143
 144     const char *la_name;
 145
 146     /* Natural or official name of the language.  */
 147
 148     const char *la_natural_name;
 149
 150     /* its symtab language-enum (defs.h).  */
 151
 152     enum language la_language;
 153
 154     /* Default range checking.  */
 155
 156     enum range_check la_range_check;
 157
 158     /* Default case sensitivity.  */
 159     enum case_sensitivity la_case_sensitivity;
 160
 161     /* Multi-dimensional array ordering.  */
 162     enum array_ordering la_array_ordering;
 163
 164     /* Style of macro expansion, if any, supported by this language.  */
 165     enum macro_expansion la_macro_expansion;
 166
 167     /* Definitions related to expression printing, prefixifying, and
 168        dumping.  */
 169
 170     const struct exp_descriptor *la_exp_desc;
 171
 172     /* Parser function.  */
 173
 174     int (*la_parser) (struct parser_state *);
 175
 176     /* Parser error function.  */
 177
 178     void (*la_error) (char *);
 179
 180     /* Given an expression *EXPP created by prefixifying the result of
 181        la_parser, perform any remaining processing necessary to complete
 182        its translation.  *EXPP may change; la_post_parser is responsible
 183        for releasing its previous contents, if necessary.  If
 184        VOID_CONTEXT_P, then no value is expected from the expression.  */
 185
 186     void (*la_post_parser) (struct expression ** expp, int void_context_p);
 187
 188     void (*la_printchar) (int ch, struct type *chtype,
 189                           struct ui_file * stream);
 190
 191     void (*la_printstr) (struct ui_file * stream, struct type *elttype,
 192                          const gdb_byte *string, unsigned int length,
 193                          const char *encoding, int force_ellipses,
 194                          const struct value_print_options *);
 195
 196     void (*la_emitchar) (int ch, struct type *chtype,
 197                          struct ui_file * stream, int quoter);
 198
 199     /* Print a type using syntax appropriate for this language.  */
 200
 201     void (*la_print_type) (struct type *, const char *, struct ui_file *, int,
 202                            int, const struct type_print_options *);
 203
 204     /* Print a typedef using syntax appropriate for this language.
 205        TYPE is the underlying type.  NEW_SYMBOL is the symbol naming
 206        the type.  STREAM is the output stream on which to print.  */
 207
 208     void (*la_print_typedef) (struct type *type, struct symbol *new_symbol,
 209                               struct ui_file *stream);
 210
 211     /* Print a value using syntax appropriate for this language.
 212
 213        TYPE is the type of the sub-object to be printed.
 214
 215        CONTENTS holds the bits of the value.  This holds the entire
 216        enclosing object.
 217
 218        EMBEDDED_OFFSET is the offset into the outermost object of the
 219        sub-object represented by TYPE.  This is the object which this
 220        call should print.  Note that the enclosing type is not
 221        available.
 222
 223        ADDRESS is the address in the inferior of the enclosing object.
 224
 225        STREAM is the stream on which the value is to be printed.
 226
 227        RECURSE is the recursion depth.  It is zero-based.
 228
 229        OPTIONS are the formatting options to be used when
 230        printing.  */
 231
 232     void (*la_val_print) (struct type *type,
 233                           const gdb_byte *contents,
 234                           int embedded_offset, CORE_ADDR address,
 235                           struct ui_file *stream, int recurse,
 236                           const struct value *val,
 237                           const struct value_print_options *options);
 238
 239     /* Print a top-level value using syntax appropriate for this language.  */
 240
 241     void (*la_value_print) (struct value *, struct ui_file *,
 242                             const struct value_print_options *);
 243
 244     /* Given a symbol VAR, and a stack frame id FRAME, read the value
 245        of the variable an return (pointer to a) struct value containing
 246        the value.
 247
 248        Throw an error if the variable cannot be found.  */
 249
 250     struct value *(*la_read_var_value) (struct symbol *var,
 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     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     /* Return class name of a mangled method name or NULL.  */
 283     char *(*la_class_name_from_physname) (const char *physname);
 284
 285     /* Table for printing expressions.  */
 286
 287     const struct op_print *la_op_print_tab;
 288
 289     /* Zero if the language has first-class arrays.  True if there are no
 290        array values, and array objects decay to pointers, as in C.  */
 291
 292     char c_style_arrays;
 293
 294     /* Index to use for extracting the first element of a string.  */
 295     char string_lower_bound;
 296
 297     /* The list of characters forming word boundaries.  */
 298     char *(*la_word_break_characters) (void);
 299
 300     /* Should return a vector of all symbols which are possible
 301        completions for TEXT.  WORD is the entire command on which the
 302        completion is being made.  If CODE is TYPE_CODE_UNDEF, then all
 303        symbols should be examined; otherwise, only STRUCT_DOMAIN
 304        symbols whose type has a code of CODE should be matched.  */
 305     VEC (char_ptr) *(*la_make_symbol_completion_list) (const char *text,
 306                                                        const char *word,
 307                                                        enum type_code code);
 308
 309     /* The per-architecture (OS/ABI) language information.  */
 310     void (*la_language_arch_info) (struct gdbarch *,
 311                                    struct language_arch_info *);
 312
 313     /* Print the index of an element of an array.  */
 314     void (*la_print_array_index) (struct value *index_value,
 315                                   struct ui_file *stream,
 316                                   const struct value_print_options *options);
 317
 318     /* Return non-zero if TYPE should be passed (and returned) by
 319        reference at the language level.  */
 320     int (*la_pass_by_reference) (struct type *type);
 321
 322     /* Obtain a string from the inferior, storing it in a newly allocated
 323        buffer in BUFFER, which should be freed by the caller.  If the
 324        in- and out-parameter *LENGTH is specified at -1, the string is
 325        read until a null character of the appropriate width is found -
 326        otherwise the string is read to the length of characters specified.
 327        On completion, *LENGTH will hold the size of the string in characters.
 328        If a *LENGTH of -1 was specified it will count only actual
 329        characters, excluding any eventual terminating null character.
 330        Otherwise *LENGTH will include all characters - including any nulls.
 331        CHARSET will hold the encoding used in the string.  */
 332     void (*la_get_string) (struct value *value, gdb_byte **buffer, int *length,
 333                            struct type **chartype, const char **charset);
 334
 335     /* Return a pointer to the function that should be used to match
 336        a symbol name against LOOKUP_NAME. This is mostly for languages
 337        such as Ada where the matching algorithm depends on LOOKUP_NAME.
 338
 339        This field may be NULL, in which case strcmp_iw will be used
 340        to perform the matching.  */
 341     symbol_name_cmp_ftype (*la_get_symbol_name_cmp) (const char *lookup_name);
 342
 343     /* Find all symbols in the current program space matching NAME in
 344        DOMAIN, according to this language's rules.
 345
 346        The search is done in BLOCK only.
 347        The caller is responsible for iterating up through superblocks
 348        if desired.
 349
 350        For each one, call CALLBACK with the symbol and the DATA
 351        argument.  If CALLBACK returns zero, the iteration ends at that
 352        point.
 353
 354        This field may not be NULL.  If the language does not need any
 355        special processing here, 'iterate_over_symbols' should be
 356        used as the definition.  */
 357     void (*la_iterate_over_symbols) (const struct block *block,
 358                                      const char *name,
 359                                      domain_enum domain,
 360                                      symbol_found_callback_ftype *callback,
 361                                      void *data);
 362
 363     /* Various operations on varobj.  */
 364     const struct lang_varobj_ops *la_varobj_ops;
 365
 366     /* If this language allows compilation from the gdb command line,
 367        this method should be non-NULL.  When called it should return
 368        an instance of struct gcc_context appropriate to the language.
 369        When defined this method must never return NULL; instead it
 370        should throw an exception on failure.  The returned compiler
 371        instance is owned by its caller and must be deallocated by
 372        calling its 'destroy' method.  */
 373
 374     struct compile_instance *(*la_get_compile_instance) (void);
 375
 376     /* This method must be defined if 'la_get_gcc_context' is defined.
 377        If 'la_get_gcc_context' is not defined, then this method is
 378        ignored.
 379
 380        This takes the user-supplied text and returns a newly malloc'd
 381        bit of code to compile.  The caller owns the result.
 382
 383        INST is the compiler instance being used.
 384        INPUT is the user's input text.
 385        GDBARCH is the architecture to use.
 386        EXPR_BLOCK is the block in which the expression is being
 387        parsed.
 388        EXPR_PC is the PC at which the expression is being parsed.  */
 389
 390     char *(*la_compute_program) (struct compile_instance *inst,
 391                                  const char *input,
 392                                  struct gdbarch *gdbarch,
 393                                  const struct block *expr_block,
 394                                  CORE_ADDR expr_pc);
 395
 396     /* Add fields above this point, so the magic number is always last.  */
 397     /* Magic number for compat checking.  */
 398
 399     long la_magic;
 400
 401   };
 402
 403 #define LANG_MAGIC      910823L
 404
 405 /* Pointer to the language_defn for our current language.  This pointer
 406    always points to *some* valid struct; it can be used without checking
 407    it for validity.
 408
 409    The current language affects expression parsing and evaluation
 410    (FIXME: it might be cleaner to make the evaluation-related stuff
 411    separate exp_opcodes for each different set of semantics.  We
 412    should at least think this through more clearly with respect to
 413    what happens if the language is changed between parsing and
 414    evaluation) and printing of things like types and arrays.  It does
 415    *not* affect symbol-reading-- each source file in a symbol-file has
 416    its own language and we should keep track of that regardless of the
 417    language when symbols are read.  If we want some manual setting for
 418    the language of symbol files (e.g. detecting when ".c" files are
 419    C++), it should be a separate setting from the current_language.  */
 420
 421 extern const struct language_defn *current_language;
 422
 423 /* Pointer to the language_defn expected by the user, e.g. the language
 424    of main(), or the language we last mentioned in a message, or C.  */
 425
 426 extern const struct language_defn *expected_language;
 427
 428 /* language_mode ==
 429    language_mode_auto:   current_language automatically set upon selection
 430    of scope (e.g. stack frame)
 431    language_mode_manual: current_language set only by user.  */
 432
 433 extern enum language_mode
 434   {
 435     language_mode_auto, language_mode_manual
 436   }
 437 language_mode;
 438
 439 struct type *language_bool_type (const struct language_defn *l,
 440                                  struct gdbarch *gdbarch);
 441
 442 struct type *language_string_char_type (const struct language_defn *l,
 443                                         struct gdbarch *gdbarch);
 444
 445 /* Look up type NAME in language L, and return its definition for architecture
 446    GDBARCH.  Returns NULL if not found.  */
 447
 448 struct type *language_lookup_primitive_type (const struct language_defn *l,
 449                                              struct gdbarch *gdbarch,
 450                                              const char *name);
 451
 452 /* Wrapper around language_lookup_primitive_type to return the
 453    corresponding symbol.  */
 454
 455 struct symbol *
 456   language_lookup_primitive_type_as_symbol (const struct language_defn *l,
 457                                             struct gdbarch *gdbarch,
 458                                             const char *name);
 459
 460 \f
 461 /* These macros define the behaviour of the expression
 462    evaluator.  */
 463
 464 /* Should we range check values against the domain of their type?  */
 465 #define RANGE_CHECK (range_check != range_check_off)
 466
 467 /* "cast" really means conversion.  */
 468 /* FIXME -- should be a setting in language_defn.  */
 469 #define CAST_IS_CONVERSION(LANG) ((LANG)->la_language == language_c  || \
 470                                   (LANG)->la_language == language_cplus || \
 471                                   (LANG)->la_language == language_objc)
 472
 473 extern void language_info (int);
 474
 475 extern enum language set_language (enum language);
 476 \f
 477
 478 /* This page contains functions that return things that are
 479    specific to languages.  Each of these functions is based on
 480    the current setting of working_lang, which the user sets
 481    with the "set language" command.  */
 482
 483 #define LA_PRINT_TYPE(type,varstring,stream,show,level,flags)           \
 484   (current_language->la_print_type(type,varstring,stream,show,level,flags))
 485
 486 #define LA_PRINT_TYPEDEF(type,new_symbol,stream) \
 487   (current_language->la_print_typedef(type,new_symbol,stream))
 488
 489 #define LA_VAL_PRINT(type,valaddr,offset,addr,stream,val,recurse,options) \
 490   (current_language->la_val_print(type,valaddr,offset,addr,stream, \
 491                                   val,recurse,options))
 492 #define LA_VALUE_PRINT(val,stream,options) \
 493   (current_language->la_value_print(val,stream,options))
 494
 495 #define LA_PRINT_CHAR(ch, type, stream) \
 496   (current_language->la_printchar(ch, type, stream))
 497 #define LA_PRINT_STRING(stream, elttype, string, length, encoding, force_ellipses, options) \
 498   (current_language->la_printstr(stream, elttype, string, length, \
 499                                  encoding, force_ellipses,options))
 500 #define LA_EMIT_CHAR(ch, type, stream, quoter) \
 501   (current_language->la_emitchar(ch, type, stream, quoter))
 502 #define LA_GET_STRING(value, buffer, length, chartype, encoding) \
 503   (current_language->la_get_string(value, buffer, length, chartype, encoding))
 504
 505 #define LA_PRINT_ARRAY_INDEX(index_value, stream, options) \
 506   (current_language->la_print_array_index(index_value, stream, options))
 507
 508 #define LA_ITERATE_OVER_SYMBOLS(BLOCK, NAME, DOMAIN, CALLBACK, DATA) \
 509   (current_language->la_iterate_over_symbols (BLOCK, NAME, DOMAIN, CALLBACK, \
 510                                               DATA))
 511
 512 /* Test a character to decide whether it can be printed in literal form
 513    or needs to be printed in another representation.  For example,
 514    in C the literal form of the character with octal value 141 is 'a'
 515    and the "other representation" is '\141'.  The "other representation"
 516    is program language dependent.  */
 517
 518 #define PRINT_LITERAL_FORM(c)           \
 519   ((c) >= 0x20                          \
 520    && ((c) < 0x7F || (c) >= 0xA0)       \
 521    && (!sevenbit_strings || (c) < 0x80))
 522
 523 /* Type predicates */
 524
 525 extern int pointer_type (struct type *);
 526
 527 /* Error messages */
 528
 529 extern void range_error (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
 530
 531 /* Data:  Does this value represent "truth" to the current language?  */
 532
 533 extern int value_true (struct value *);
 534
 535 /* Misc:  The string representing a particular enum language.  */
 536
 537 extern enum language language_enum (char *str);
 538
 539 extern const struct language_defn *language_def (enum language);
 540
 541 extern const char *language_str (enum language);
 542
 543 /* Add a language to the set known by GDB (at initialization time).  */
 544
 545 extern void add_language (const struct language_defn *);
 546
 547 extern enum language get_frame_language (void); /* In stack.c */
 548
 549 /* Check for a language-specific trampoline.  */
 550
 551 extern CORE_ADDR skip_language_trampoline (struct frame_info *, CORE_ADDR pc);
 552
 553 /* Return demangled language symbol, or NULL.  */
 554 extern char *language_demangle (const struct language_defn *current_language,
 555                                 const char *mangled, int options);
 556
 557 /* Return class name from physname, or NULL.  */
 558 extern char *language_class_name_from_physname (const struct language_defn *,
 559                                                 const char *physname);
 560
 561 /* Splitting strings into words.  */
 562 extern char *default_word_break_characters (void);
 563
 564 /* Print the index of an array element using the C99 syntax.  */
 565 extern void default_print_array_index (struct value *index_value,
 566                                        struct ui_file *stream,
 567                                        const struct value_print_options *options);
 568
 569 /* Return non-zero if TYPE should be passed (and returned) by
 570    reference at the language level.  */
 571 int language_pass_by_reference (struct type *type);
 572
 573 /* Return zero; by default, types are passed by value at the language
 574    level.  The target ABI may pass or return some structs by reference
 575    independent of this.  */
 576 int default_pass_by_reference (struct type *type);
 577
 578 /* The default implementation of la_print_typedef.  */
 579 void default_print_typedef (struct type *type, struct symbol *new_symbol,
 580                             struct ui_file *stream);
 581
 582 void default_get_string (struct value *value, gdb_byte **buffer, int *length,
 583                          struct type **char_type, const char **charset);
 584
 585 void c_get_string (struct value *value, gdb_byte **buffer, int *length,
 586                    struct type **char_type, const char **charset);
 587
 588 #endif /* defined (LANGUAGE_H) */