1 /* The lang_hooks data structure.
2 Copyright (C) 2001-2023 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 #ifndef GCC_LANG_HOOKS_H
21 #define GCC_LANG_HOOKS_H
22
23 /* FIXME: This file should be #include-d after tree.h (for enum tree_code). */
24
25 struct diagnostic_info;
26
27 struct gimplify_omp_ctx;
28
29 struct array_descr_info;
30
31 /* A print hook for print_tree (). */
32 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
33
34 enum classify_record
35 { RECORD_IS_STRUCT, RECORD_IS_CLASS, RECORD_IS_INTERFACE };
36
37 class substring_loc;
38
39 /* The following hooks are documented in langhooks.cc. Must not be
40 NULL. */
41
42 struct lang_hooks_for_tree_inlining
43 {
44 bool (*var_mod_type_p) (tree, tree);
45 };
46
47 /* The following hooks are used by tree-dump.cc. */
48
49 struct lang_hooks_for_tree_dump
50 {
51 /* Dump language-specific parts of tree nodes. Returns nonzero if it
52 does not want the usual dumping of the second argument. */
53 bool (*dump_tree) (void *, tree);
54
55 /* Determine type qualifiers in a language-specific way. */
56 int (*type_quals) (const_tree);
57 };
58
59 /* Hooks related to types. */
60
61 struct lang_hooks_for_types
62 {
63 /* Return a new type (with the indicated CODE), doing whatever
64 language-specific processing is required. */
65 tree (*make_type) (enum tree_code);
66
67 /* Make an enum type with the given name and values, associating
68 them all with the given source location. */
69 tree (*simulate_enum_decl) (location_t, const char *, vec<string_int_pair> *);
70
71 /* Do the equivalent of:
72
73 typedef struct NAME { FIELDS; } NAME;
74
75 associating it with location LOC. Return the associated RECORD_TYPE.
76
77 FIELDS is a list of FIELD_DECLs, in layout order. */
78 tree (*simulate_record_decl) (location_t loc, const char *name,
79 array_slice<const tree> fields);
80
81 /* Return what kind of RECORD_TYPE this is, mainly for purposes of
82 debug information. If not defined, record types are assumed to
83 be structures. */
84 enum classify_record (*classify_record) (tree);
85
86 /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
87 mode. */
88 tree (*type_for_mode) (machine_mode, int);
89
90 /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
91 integer type with at least that precision. */
92 tree (*type_for_size) (unsigned, int);
93
94 /* True if the type is an instantiation of a generic type,
95 e.g. C++ template implicit specializations. */
96 bool (*generic_p) (const_tree);
97
98 /* Returns the TREE_VEC of elements of a given generic argument pack. */
99 tree (*get_argument_pack_elems) (const_tree);
100
101 /* Given a type, apply default promotions to unnamed function
102 arguments and return the new type. Return the same type if no
103 change. Required by any language that supports variadic
104 arguments. The default hook dies. */
105 tree (*type_promotes_to) (tree);
106
107 /* Register TYPE as a builtin type with the indicated NAME. The
108 TYPE is placed in the outermost lexical scope. The semantics
109 should be analogous to:
110
111 typedef TYPE NAME;
112
113 in C. The default hook ignores the declaration. */
114 void (*register_builtin_type) (tree, const char *);
115
116 /* This routine is called in tree.cc to print an error message for
117 invalid use of an incomplete type. VALUE is the expression that
118 was used (or 0 if that isn't known) and TYPE is the type that was
119 invalid. LOC is the location of the use. */
120 void (*incomplete_type_error) (location_t loc, const_tree value,
121 const_tree type);
122
123 /* Called from assign_temp to return the maximum size, if there is one,
124 for a type. */
125 tree (*max_size) (const_tree);
126
127 /* Register language specific type size variables as potentially OpenMP
128 firstprivate variables. */
129 void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
130
131 /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
132 Called only after doing all language independent checks.
133 At present, this function is only called when both TYPE1 and TYPE2 are
134 FUNCTION_TYPE or METHOD_TYPE. */
135 bool (*type_hash_eq) (const_tree, const_tree);
136
137 /* If non-NULL, return TYPE1 with any language-specific modifiers copied from
138 TYPE2. */
139 tree (*copy_lang_qualifiers) (const_tree, const_tree);
140
141 /* Return TRUE if TYPE uses a hidden descriptor and fills in information
142 for the debugger about the array bounds, strides, etc. */
143 bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
144
145 /* Fill in information for the debugger about the bounds of TYPE. */
146 void (*get_subrange_bounds) (const_tree, tree *, tree *);
147
148 /* Called on INTEGER_TYPEs. Return NULL_TREE for non-biased types. For
149 biased types, return as an INTEGER_CST node the value that is represented
150 by a physical zero. */
151 tree (*get_type_bias) (const_tree);
152
153 /* A type descriptive of TYPE's complex layout generated to help the
154 debugger to decode variable-length or self-referential constructs.
155 This is only used for the AT_GNAT_descriptive_type DWARF attribute. */
156 tree (*descriptive_type) (const_tree);
157
158 /* If we requested a pointer to a vector, build up the pointers that
159 we stripped off while looking for the inner type. Similarly for
160 return values from functions. The argument TYPE is the top of the
161 chain, and BOTTOM is the new type which we will point to. */
162 tree (*reconstruct_complex_type) (tree, tree);
163
164 /* Returns the tree that represents the underlying data type used to
165 implement the enumeration. The default implementation will just use
166 type_for_size. Used in dwarf2out.cc to add a DW_AT_type base type
167 reference to a DW_TAG_enumeration. */
168 tree (*enum_underlying_base_type) (const_tree);
169
170 /* Return a type to use in the debug info instead of TYPE, or NULL_TREE to
171 keep TYPE. This is useful to keep a single "source type" when the
172 middle-end uses specialized types, for instance constrained discriminated
173 types in Ada. */
174 tree (*get_debug_type) (const_tree);
175
176 /* Return TRUE if TYPE implements a fixed point type and fills in information
177 for the debugger about scale factor, etc. */
178 bool (*get_fixed_point_type_info) (const_tree,
179 struct fixed_point_type_info *);
180
181 /* Returns -1 if dwarf ATTR shouldn't be added for TYPE, or the attribute
182 value otherwise. */
183 int (*type_dwarf_attribute) (const_tree, int);
184
185 /* Returns a tree for the unit size of T excluding tail padding that
186 might be used by objects inheriting from T. */
187 tree (*unit_size_without_reusable_padding) (tree);
188
189 /* Returns type corresponding to FIELD's type when FIELD is a C++ base class
190 i.e., type without virtual base classes or tail padding. Returns
191 NULL_TREE otherwise. */
192 tree (*classtype_as_base) (const_tree);
193 };
194
195 /* Language hooks related to decls and the symbol table. */
196
197 struct lang_hooks_for_decls
198 {
199 /* Return true if we are in the global binding level. This hook is really
200 needed only if the language supports variable-sized types at the global
201 level, i.e. declared outside subprograms. */
202 bool (*global_bindings_p) (void);
203
204 /* Function to add a decl to the current scope level. Takes one
205 argument, a decl to add. Returns that decl, or, if the same
206 symbol is already declared, may return a different decl for that
207 name. */
208 tree (*pushdecl) (tree);
209
210 /* Returns the chain of decls so far in the current scope level. */
211 tree (*getdecls) (void);
212
213 /* Returns -1 if dwarf ATTR shouldn't be added for DECL, or the attribute
214 value otherwise. */
215 int (*decl_dwarf_attribute) (const_tree, int);
216
217 /* Returns True if the parameter is a generic parameter decl
218 of a generic type, e.g a template template parameter for the C++ FE. */
219 bool (*generic_generic_parameter_decl_p) (const_tree);
220
221 /* Determine if a function parameter got expanded from a
222 function parameter pack. */
223 bool (*function_parm_expanded_from_pack_p) (tree, tree);
224
225 /* Returns the generic declaration of a generic function instantiations. */
226 tree (*get_generic_function_decl) (const_tree);
227
228 /* Returns true when we should warn for an unused global DECL.
229 We will already have checked that it has static binding. */
230 bool (*warn_unused_global) (const_tree);
231
232 /* Perform any post compilation-proper parser cleanups and
233 processing. This is currently only needed for the C++ parser,
234 which hopefully can be cleaned up so this hook is no longer
235 necessary. */
236 void (*post_compilation_parsing_cleanups) (void);
237
238 /* True if this decl may be called via a sibcall. */
239 bool (*ok_for_sibcall) (const_tree);
240
241 /* Return a tree for the actual data of an array descriptor - or NULL_TREE
242 if original tree is not an array descriptor. If the second argument
243 is true, only the TREE_TYPE is returned without generating a new tree. */
244 tree (*omp_array_data) (tree, bool);
245
246 /* Return a tree for the actual data of an array descriptor - or NULL_TREE
247 if original tree is not an array descriptor. If the second argument
248 is true, only the TREE_TYPE is returned without generating a new tree. */
249 tree (*omp_array_size) (tree, gimple_seq *pre_p);
250
251 /* True if OpenMP should regard this DECL as being a scalar which has Fortran's
252 allocatable or pointer attribute. */
253 bool (*omp_is_allocatable_or_ptr) (const_tree);
254
255 /* Check whether this DECL belongs to a Fortran optional argument.
256 With 'for_present_check' set to false, decls which are optional parameters
257 themselve are returned as tree - or a NULL_TREE otherwise. Those decls are
258 always pointers. With 'for_present_check' set to true, the decl for
259 checking whether an argument is present is returned; for arguments with
260 value attribute this is the hidden argument and of BOOLEAN_TYPE. If the
261 decl is unrelated to optional arguments, NULL_TREE is returned. */
262 tree (*omp_check_optional_argument) (tree, bool);
263
264 /* True if OpenMP should privatize what this DECL points to rather
265 than the DECL itself. */
266 bool (*omp_privatize_by_reference) (const_tree);
267
268 /* Return sharing kind if OpenMP sharing attribute of DECL is
269 predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise. */
270 enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
271
272 /* Return mapping kind if OpenMP mapping attribute of DECL is
273 predetermined, OMP_CLAUSE_DEFAULTMAP_CATEGORY_UNSPECIFIED otherwise. */
274 enum omp_clause_defaultmap_kind (*omp_predetermined_mapping) (tree);
275
276 /* Return decl that should be reported for DEFAULT(NONE) failure
277 diagnostics. Usually the DECL passed in. */
278 tree (*omp_report_decl) (tree);
279
280 /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
281 disregarded in OpenMP construct, because it is going to be
282 remapped during OpenMP lowering. SHARED is true if DECL
283 is going to be shared, false if it is going to be privatized. */
284 bool (*omp_disregard_value_expr) (tree, bool);
285
286 /* Return true if DECL that is shared iff SHARED is true should
287 be put into OMP_CLAUSE_PRIVATE_DEBUG. */
288 bool (*omp_private_debug_clause) (tree, bool);
289
290 /* Return true if DECL in private clause needs
291 OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause. */
292 bool (*omp_private_outer_ref) (tree);
293
294 /* Build and return code for a default constructor for DECL in
295 response to CLAUSE. OUTER is corresponding outer region's
296 variable if needed. Return NULL if nothing to be done. */
297 tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
298
299 /* Build and return code for a copy constructor from SRC to DST. */
300 tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
301
302 /* Similarly, except use an assignment operator instead. */
303 tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
304
305 /* Build and return code for a constructor of DST that sets it to
306 SRC + ADD. */
307 tree (*omp_clause_linear_ctor) (tree clause, tree dst, tree src, tree add);
308
309 /* Build and return code destructing DECL. Return NULL if nothing
310 to be done. */
311 tree (*omp_clause_dtor) (tree clause, tree decl);
312
313 /* Do language specific checking on an implicitly determined clause. */
314 void (*omp_finish_clause) (tree clause, gimple_seq *pre_p, bool);
315
316 /* Return true if DECL is an allocatable variable (for the purpose of
317 implicit mapping). */
318 bool (*omp_allocatable_p) (tree decl);
319
320 /* Return true if DECL is a scalar variable (for the purpose of
321 implicit firstprivatization). If 'ptr_or', pointers and
322 allocatables are also permitted. */
323 bool (*omp_scalar_p) (tree decl, bool ptr_ok);
324
325 /* Return true if DECL is a scalar variable with Fortran target but not
326 allocatable or pointer attribute (for the purpose of implicit mapping). */
327 bool (*omp_scalar_target_p) (tree decl);
328
329 /* Return a pointer to the tree representing the initializer
330 expression for the non-local variable DECL. Return NULL if
331 DECL is not initialized. */
332 tree *(*omp_get_decl_init) (tree decl);
333
334 /* Free any extra memory used to hold initializer information for
335 variable declarations. omp_get_decl_init must not be called
336 after calling this. */
337 void (*omp_finish_decl_inits) (void);
338 };
339
340 /* Language hooks related to LTO serialization. */
341
342 struct lang_hooks_for_lto
343 {
344 /* Begin a new LTO section named NAME. */
345 void (*begin_section) (const char *name);
346
347 /* Write DATA of length LEN to the currently open LTO section. BLOCK is a
348 pointer to the dynamically allocated memory containing DATA. The
349 append_data function is responsible for freeing it when it is no longer
350 needed. */
351 void (*append_data) (const void *data, size_t len, void *block);
352
353 /* End the previously begun LTO section. */
354 void (*end_section) (void);
355 };
356
357 /* Language-specific hooks. See langhooks-def.h for defaults. */
358
359 struct lang_hooks
360 {
361 /* String identifying the front end and optionally language standard
362 version, e.g. "GNU C++98". */
363 const char *name;
364
365 /* sizeof (struct lang_identifier), so make_node () creates
366 identifier nodes long enough for the language-specific slots. */
367 size_t identifier_size;
368
369 /* Remove any parts of the tree that are used only by the FE. */
370 void (*free_lang_data) (tree);
371
372 /* Determines the size of any language-specific tcc_constant,
373 tcc_exceptional or tcc_type nodes. Since it is called from
374 make_node, the only information available is the tree code.
375 Expected to die on unrecognized codes. */
376 size_t (*tree_size) (enum tree_code);
377
378 /* Return the language mask used for converting argv into a sequence
379 of options. */
380 unsigned int (*option_lang_mask) (void);
381
382 /* Initialize variables in an options structure. */
383 void (*init_options_struct) (struct gcc_options *opts);
384
385 /* After the initialize_diagnostics hook is called, do any simple
386 initialization needed before any calls to handle_option, other
387 than that done by the init_options_struct hook. */
388 void (*init_options) (unsigned int decoded_options_count,
389 struct cl_decoded_option *decoded_options);
390
391 /* Callback used to perform language-specific initialization for the
392 global diagnostic context structure. */
393 void (*initialize_diagnostics) (diagnostic_context *);
394
395 /* Beginning the main source file. */
396 void (*preprocess_main_file) (cpp_reader *, line_maps *,
397 const line_map_ordinary *);
398
399 /* Adjust libcpp options and callbacks. */
400 void (*preprocess_options) (cpp_reader *);
401
402 /* Undefining a macro. */
403 void (*preprocess_undef) (cpp_reader *, location_t, cpp_hashnode *);
404
405 /* Observer for preprocessing stream. */
406 uintptr_t (*preprocess_token) (cpp_reader *, const cpp_token *, uintptr_t);
407 /* Various flags it can return about the token. */
408 enum PT_flags
409 {
410 PT_begin_pragma = 1 << 0
411 };
412
413 /* Register language-specific dumps. */
414 void (*register_dumps) (gcc::dump_manager *);
415
416 /* Return true if a warning should be given about option OPTION,
417 which is for the wrong language, false if it should be quietly
418 ignored. */
419 bool (*complain_wrong_lang_p) (const struct cl_option *option);
420
421 /* Handle the switch CODE, which has real type enum opt_code from
422 options.h. If the switch takes an argument, it is passed in ARG
423 which points to permanent storage. The handler is responsible for
424 checking whether ARG is NULL, which indicates that no argument
425 was in fact supplied. For -f and -W switches, VALUE is 1 or 0
426 for the positive and negative forms respectively. HANDLERS should
427 be passed to any recursive handle_option calls. LOC is the
428 location of the option.
429
430 Return true if the switch is valid, false if invalid. */
431 bool (*handle_option) (size_t code, const char *arg, HOST_WIDE_INT value,
432 int kind, location_t loc,
433 const struct cl_option_handlers *handlers);
434
435 /* Called when all command line options have been parsed to allow
436 further processing and initialization
437
438 Should return true to indicate that a compiler back-end is
439 not required, such as with the -E option.
440
441 If errorcount is nonzero after this call the compiler exits
442 immediately and the finish hook is not called. */
443 bool (*post_options) (const char **);
444
445 /* Called after post_options to initialize the front end. Return
446 false to indicate that no further compilation be performed, in
447 which case the finish hook is called immediately. */
448 bool (*init) (void);
449
450 /* Called at the end of compilation, as a finalizer. */
451 void (*finish) (void);
452
453 /* Parses the entire file. */
454 void (*parse_file) (void);
455
456 /* Determines if it's ok for a function to have no noreturn attribute. */
457 bool (*missing_noreturn_ok_p) (tree);
458
459 /* Called to obtain the alias set to be used for an expression or type.
460 Returns -1 if the language does nothing special for it. */
461 alias_set_type (*get_alias_set) (tree);
462
463 /* Function to finish handling an incomplete decl at the end of
464 compilation. Default hook is does nothing. */
465 void (*finish_incomplete_decl) (tree);
466
467 /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
468 DECL_NODE with a newly GC-allocated copy. */
469 void (*dup_lang_specific_decl) (tree);
470
471 /* Set the DECL_ASSEMBLER_NAME for a node. If it is the sort of
472 thing that the assembler should talk about, set
473 DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
474 Otherwise, set it to the ERROR_MARK_NODE to ensure that the
475 assembler does not talk about it. */
476 void (*set_decl_assembler_name) (tree);
477
478 /* Overwrite the DECL_ASSEMBLER_NAME for a node. The name is being
479 changed (including to or from NULL_TREE). */
480 void (*overwrite_decl_assembler_name) (tree, tree);
481
482 /* The front end can add its own statistics to -fmem-report with
483 this hook. It should output to stderr. */
484 void (*print_statistics) (void);
485
486 /* Called by print_tree when there is a tree of class tcc_exceptional
487 or tcc_constant that it doesn't know how to display. */
488 lang_print_tree_hook print_xnode;
489
490 /* Called to print language-dependent parts of tcc_decl, tcc_type,
491 and IDENTIFIER_NODE nodes. */
492 lang_print_tree_hook print_decl;
493 lang_print_tree_hook print_type;
494 lang_print_tree_hook print_identifier;
495
496 /* Computes the name to use to print a declaration. DECL is the
497 non-NULL declaration in question. VERBOSITY determines what
498 information will be printed: 0: DECL_NAME, demangled as
499 necessary. 1: and scope information. 2: and any other
500 information that might be interesting, such as function parameter
501 types in C++. The name is in the internal character set and
502 needs to be converted to the locale character set of diagnostics,
503 or to the execution character set for strings such as
504 __PRETTY_FUNCTION__. */
505 const char *(*decl_printable_name) (tree decl, int verbosity);
506
507 /* Computes the dwarf-2/3 name for a tree. VERBOSITY determines what
508 information will be printed: 0: DECL_NAME, demangled as
509 necessary. 1: and scope information. */
510 const char *(*dwarf_name) (tree, int verbosity);
511
512 /* This compares two types for equivalence ("compatible" in C-based languages).
513 This routine should only return 1 if it is sure. It should not be used
514 in contexts where erroneously returning 0 causes problems. */
515 int (*types_compatible_p) (tree x, tree y);
516
517 /* Called by report_error_function to print out function name. */
518 void (*print_error_function) (diagnostic_context *, const char *,
519 struct diagnostic_info *);
520
521 /* Convert a character from the host's to the target's character
522 set. The character should be in what C calls the "basic source
523 character set" (roughly, the set of characters defined by plain
524 old ASCII). The default is to return the character unchanged,
525 which is correct in most circumstances. Note that both argument
526 and result should be sign-extended under -fsigned-char,
527 zero-extended under -fno-signed-char. */
528 HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
529
530 /* Pointers to machine-independent attribute tables, for front ends
531 using attribs.cc. If one is NULL, it is ignored. Respectively, a
532 table of attributes specific to the language, a table of
533 attributes common to two or more languages (to allow easy
534 sharing), and a table of attributes for checking formats. */
535 const struct attribute_spec *attribute_table;
536 const struct attribute_spec *common_attribute_table;
537 const struct attribute_spec *format_attribute_table;
538
539 struct lang_hooks_for_tree_inlining tree_inlining;
540
541 struct lang_hooks_for_tree_dump tree_dump;
542
543 struct lang_hooks_for_decls decls;
544
545 struct lang_hooks_for_types types;
546
547 struct lang_hooks_for_lto lto;
548
549 /* Returns a TREE_VEC of the generic parameters of an instantiation of
550 a generic type or decl, e.g. C++ template instantiation. If
551 TREE_CHAIN of the return value is set, it is an INTEGER_CST
552 indicating how many of the elements are non-default. */
553 tree (*get_innermost_generic_parms) (const_tree);
554
555 /* Returns the TREE_VEC of arguments of an instantiation
556 of a generic type of decl, e.g. C++ template instantiation. */
557 tree (*get_innermost_generic_args) (const_tree);
558
559 /* Determine if a tree is a function parameter pack. */
560 bool (*function_parameter_pack_p) (const_tree);
561
562 /* Perform language-specific gimplification on the argument. Returns an
563 enum gimplify_status, though we can't see that type here. */
564 int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
565
566 /* Do language specific processing in the builtin function DECL */
567 tree (*builtin_function) (tree decl);
568
569 /* Like builtin_function, but make sure the scope is the external scope.
570 This is used to delay putting in back end builtin functions until the ISA
571 that defines the builtin is declared via function specific target options,
572 which can save memory for machines like the x86_64 that have multiple
573 ISAs. If this points to the same function as builtin_function, the
574 backend must add all of the builtins at program initialization time. */
575 tree (*builtin_function_ext_scope) (tree decl);
576
577 /* Do language-specific processing for target-specific built-in
578 function DECL, so that it is defined in the global scope (only)
579 and is available without needing to be explicitly declared.
580
581 This is intended for targets that want to inject declarations of
582 built-in functions into the source language (such as in response
583 to a pragma) rather than providing them in the source language itself. */
584 tree (*simulate_builtin_function_decl) (tree decl);
585
586 /* Used to set up the tree_contains_structure array for a frontend. */
587 void (*init_ts) (void);
588
589 /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
590 to a contained expression or DECL, possibly updating *TC or *SE
591 if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating. */
592 tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
593
594 /* The EH personality function decl. */
595 tree (*eh_personality) (void);
596
597 /* Map a type to a runtime object to match type. */
598 tree (*eh_runtime_type) (tree);
599
600 /* If non-NULL, this is a function that returns a function decl to be
601 executed if an unhandled exception is propagated out of a cleanup
602 region. For example, in C++, an exception thrown by a destructor
603 during stack unwinding is required to result in a call to
604 `std::terminate', so the C++ version of this function returns a
605 FUNCTION_DECL for `std::terminate'. */
606 tree (*eh_protect_cleanup_actions) (void);
607
608 /* Return true if a stmt can fallthru. Used by block_may_fallthru
609 to possibly handle language trees. */
610 bool (*block_may_fallthru) (const_tree);
611
612 /* True if this language uses __cxa_end_cleanup when the ARM EABI
613 is enabled. */
614 bool eh_use_cxa_end_cleanup;
615
616 /* True if this language requires deep unsharing of tree nodes prior to
617 gimplification. */
618 bool deep_unsharing;
619
620 /* True if this language may use custom descriptors for nested functions
621 instead of trampolines. */
622 bool custom_function_descriptors;
623
624 /* True if this language emits begin stmt notes. */
625 bool emits_begin_stmt;
626
627 /* Run all lang-specific selftests. */
628 void (*run_lang_selftests) (void);
629
630 /* Attempt to determine the source location of the substring.
631 If successful, return NULL and write the source location to *OUT_LOC.
632 Otherwise return an error message. Error messages are intended
633 for GCC developers (to help debugging) rather than for end-users. */
634 const char *(*get_substring_location) (const substring_loc &,
635 location_t *out_loc);
636
637 /* Invoked before the early_finish debug hook is invoked. */
638 void (*finalize_early_debug) (void);
639
640 /* Get a value for the SARIF v2.1.0 "artifact.sourceLanguage" property
641 for FILENAME, or return NULL.
642 See SARIF v2.1.0 Appendix J for suggested values for common programming
643 languages. */
644 const char *(*get_sarif_source_language) (const char *filename);
645
646 /* Whenever you add entries here, make sure you adjust langhooks-def.h
647 and langhooks.cc accordingly. */
648 };
649
650 /* Each front end provides its own. */
651 extern struct lang_hooks lang_hooks;
652
653 extern tree add_builtin_function (const char *name, tree type,
654 int function_code, enum built_in_class cl,
655 const char *library_name,
656 tree attrs);
657
658 extern tree add_builtin_function_ext_scope (const char *name, tree type,
659 int function_code,
660 enum built_in_class cl,
661 const char *library_name,
662 tree attrs);
663 extern tree simulate_builtin_function_decl (location_t, const char *, tree,
664 int, const char *, tree);
665 extern tree add_builtin_type (const char *name, tree type);
666
667 /* Language helper functions. */
668
669 extern bool lang_GNU_C (void);
670 extern bool lang_GNU_CXX (void);
671 extern bool lang_GNU_Fortran (void);
672 extern bool lang_GNU_OBJC (void);
673
674 #endif /* GCC_LANG_HOOKS_H */