1/* The lang_hooks data structure.
2 Copyright (C) 2001-2017 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 3, or (at your option)
9any later version.
10
11GCC is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14GNU General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along 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
25struct diagnostic_info;
26
27struct gimplify_omp_ctx;
28
29struct array_descr_info;
30
31/* A print hook for print_tree (). */
32typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
33
34enum classify_record
35 { RECORD_IS_STRUCT, RECORD_IS_CLASS, RECORD_IS_INTERFACE };
36
37class substring_loc;
38
39/* The following hooks are documented in langhooks.c. Must not be
40 NULL. */
41
42struct 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.c. */
48
49struct 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
61struct 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 /* Return what kind of RECORD_TYPE this is, mainly for purposes of
68 debug information. If not defined, record types are assumed to
69 be structures. */
70 enum classify_record (*classify_record) (tree);
71
72 /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
73 mode. */
74 tree (*type_for_mode) (machine_mode, int);
75
76 /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
77 integer type with at least that precision. */
78 tree (*type_for_size) (unsigned, int);
79
80 /* True if the type is an instantiation of a generic type,
81 e.g. C++ template implicit specializations. */
82 bool (*generic_p) (const_tree);
83
84 /* Returns the TREE_VEC of elements of a given generic argument pack. */
85 tree (*get_argument_pack_elems) (const_tree);
86
87 /* Given a type, apply default promotions to unnamed function
88 arguments and return the new type. Return the same type if no
89 change. Required by any language that supports variadic
90 arguments. The default hook dies. */
91 tree (*type_promotes_to) (tree);
92
93 /* Register TYPE as a builtin type with the indicated NAME. The
94 TYPE is placed in the outermost lexical scope. The semantics
95 should be analogous to:
96
97 typedef TYPE NAME;
98
99 in C. The default hook ignores the declaration. */
100 void (*register_builtin_type) (tree, const char *);
101
102 /* This routine is called in tree.c to print an error message for
103 invalid use of an incomplete type. VALUE is the expression that
104 was used (or 0 if that isn't known) and TYPE is the type that was
105 invalid. LOC is the location of the use. */
106 void (*incomplete_type_error) (location_t loc, const_tree value,
107 const_tree type);
108
109 /* Called from assign_temp to return the maximum size, if there is one,
110 for a type. */
111 tree (*max_size) (const_tree);
112
113 /* Register language specific type size variables as potentially OpenMP
114 firstprivate variables. */
115 void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
116
117 /* Return true if TYPE is a mappable type. */
118 bool (*omp_mappable_type) (tree type);
119
120 /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
121 Called only after doing all language independent checks.
122 At present, this function is only called when both TYPE1 and TYPE2 are
123 FUNCTION_TYPE or METHOD_TYPE. */
124 bool (*type_hash_eq) (const_tree, const_tree);
125
126 /* If non-NULL, return TYPE1 with any language-specific modifiers copied from
127 TYPE2. */
128 tree (*copy_lang_qualifiers) (const_tree, const_tree);
129
130 /* Return TRUE if TYPE uses a hidden descriptor and fills in information
131 for the debugger about the array bounds, strides, etc. */
132 bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
133
134 /* Fill in information for the debugger about the bounds of TYPE. */
135 void (*get_subrange_bounds) (const_tree, tree *, tree *);
136
137 /* Called on INTEGER_TYPEs. Return NULL_TREE for non-biased types. For
138 biased types, return as an INTEGER_CST node the value that is represented
139 by a physical zero. */
140 tree (*get_type_bias) (const_tree);
141
142 /* A type descriptive of TYPE's complex layout generated to help the
143 debugger to decode variable-length or self-referential constructs.
144 This is only used for the AT_GNAT_descriptive_type DWARF attribute. */
145 tree (*descriptive_type) (const_tree);
146
147 /* If we requested a pointer to a vector, build up the pointers that
148 we stripped off while looking for the inner type. Similarly for
149 return values from functions. The argument TYPE is the top of the
150 chain, and BOTTOM is the new type which we will point to. */
151 tree (*reconstruct_complex_type) (tree, tree);
152
153 /* Returns the tree that represents the underlying data type used to
154 implement the enumeration. The default implementation will just use
155 type_for_size. Used in dwarf2out.c to add a DW_AT_type base type
156 reference to a DW_TAG_enumeration. */
157 tree (*enum_underlying_base_type) (const_tree);
158
159 /* Return a type to use in the debug info instead of TYPE, or NULL_TREE to
160 keep TYPE. This is useful to keep a single "source type" when the
161 middle-end uses specialized types, for instance constrained discriminated
162 types in Ada. */
163 tree (*get_debug_type) (const_tree);
164
165 /* Return TRUE if TYPE implements a fixed point type and fills in information
166 for the debugger about scale factor, etc. */
167 bool (*get_fixed_point_type_info) (const_tree,
168 struct fixed_point_type_info *);
169
170 /* Returns -1 if dwarf ATTR shouldn't be added for TYPE, or the attribute
171 value otherwise. */
172 int (*type_dwarf_attribute) (const_tree, int);
173
174 /* Returns a tree for the unit size of T excluding tail padding that
175 might be used by objects inheriting from T. */
176 tree (*unit_size_without_reusable_padding) (tree);
177};
178
179/* Language hooks related to decls and the symbol table. */
180
181struct lang_hooks_for_decls
182{
183 /* Return true if we are in the global binding level. This hook is really
184 needed only if the language supports variable-sized types at the global
185 level, i.e. declared outside subprograms. */
186 bool (*global_bindings_p) (void);
187
188 /* Function to add a decl to the current scope level. Takes one
189 argument, a decl to add. Returns that decl, or, if the same
190 symbol is already declared, may return a different decl for that
191 name. */
192 tree (*pushdecl) (tree);
193
194 /* Returns the chain of decls so far in the current scope level. */
195 tree (*getdecls) (void);
196
197 /* Returns -1 if dwarf ATTR shouldn't be added for DECL, or the attribute
198 value otherwise. */
199 int (*decl_dwarf_attribute) (const_tree, int);
200
201 /* Returns True if the parameter is a generic parameter decl
202 of a generic type, e.g a template template parameter for the C++ FE. */
203 bool (*generic_generic_parameter_decl_p) (const_tree);
204
205 /* Determine if a function parameter got expanded from a
206 function parameter pack. */
207 bool (*function_parm_expanded_from_pack_p) (tree, tree);
208
209 /* Returns the generic declaration of a generic function instantiations. */
210 tree (*get_generic_function_decl) (const_tree);
211
212 /* Returns true when we should warn for an unused global DECL.
213 We will already have checked that it has static binding. */
214 bool (*warn_unused_global) (const_tree);
215
216 /* Perform any post compilation-proper parser cleanups and
217 processing. This is currently only needed for the C++ parser,
218 which hopefully can be cleaned up so this hook is no longer
219 necessary. */
220 void (*post_compilation_parsing_cleanups) (void);
221
222 /* True if this decl may be called via a sibcall. */
223 bool (*ok_for_sibcall) (const_tree);
224
225 /* True if OpenMP should privatize what this DECL points to rather
226 than the DECL itself. */
227 bool (*omp_privatize_by_reference) (const_tree);
228
229 /* Return sharing kind if OpenMP sharing attribute of DECL is
230 predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise. */
231 enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
232
233 /* Return decl that should be reported for DEFAULT(NONE) failure
234 diagnostics. Usually the DECL passed in. */
235 tree (*omp_report_decl) (tree);
236
237 /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
238 disregarded in OpenMP construct, because it is going to be
239 remapped during OpenMP lowering. SHARED is true if DECL
240 is going to be shared, false if it is going to be privatized. */
241 bool (*omp_disregard_value_expr) (tree, bool);
242
243 /* Return true if DECL that is shared iff SHARED is true should
244 be put into OMP_CLAUSE_PRIVATE_DEBUG. */
245 bool (*omp_private_debug_clause) (tree, bool);
246
247 /* Return true if DECL in private clause needs
248 OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause. */
249 bool (*omp_private_outer_ref) (tree);
250
251 /* Build and return code for a default constructor for DECL in
252 response to CLAUSE. OUTER is corresponding outer region's
253 variable if needed. Return NULL if nothing to be done. */
254 tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
255
256 /* Build and return code for a copy constructor from SRC to DST. */
257 tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
258
259 /* Similarly, except use an assignment operator instead. */
260 tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
261
262 /* Build and return code for a constructor of DST that sets it to
263 SRC + ADD. */
264 tree (*omp_clause_linear_ctor) (tree clause, tree dst, tree src, tree add);
265
266 /* Build and return code destructing DECL. Return NULL if nothing
267 to be done. */
268 tree (*omp_clause_dtor) (tree clause, tree decl);
269
270 /* Do language specific checking on an implicitly determined clause. */
271 void (*omp_finish_clause) (tree clause, gimple_seq *pre_p);
272
273 /* Return true if DECL is a scalar variable (for the purpose of
274 implicit firstprivatization). */
275 bool (*omp_scalar_p) (tree decl);
276};
277
278/* Language hooks related to LTO serialization. */
279
280struct lang_hooks_for_lto
281{
282 /* Begin a new LTO section named NAME. */
283 void (*begin_section) (const char *name);
284
285 /* Write DATA of length LEN to the currently open LTO section. BLOCK is a
286 pointer to the dynamically allocated memory containing DATA. The
287 append_data function is responsible for freeing it when it is no longer
288 needed. */
289 void (*append_data) (const void *data, size_t len, void *block);
290
291 /* End the previously begun LTO section. */
292 void (*end_section) (void);
293};
294
295/* Language-specific hooks. See langhooks-def.h for defaults. */
296
297struct lang_hooks
298{
299 /* String identifying the front end and optionally language standard
300 version, e.g. "GNU C++98". */
301 const char *name;
302
303 /* sizeof (struct lang_identifier), so make_node () creates
304 identifier nodes long enough for the language-specific slots. */
305 size_t identifier_size;
306
307 /* Remove any parts of the tree that are used only by the FE. */
308 void (*free_lang_data) (tree);
309
310 /* Determines the size of any language-specific tcc_constant,
311 tcc_exceptional or tcc_type nodes. Since it is called from
312 make_node, the only information available is the tree code.
313 Expected to die on unrecognized codes. */
314 size_t (*tree_size) (enum tree_code);
315
316 /* Return the language mask used for converting argv into a sequence
317 of options. */
318 unsigned int (*option_lang_mask) (void);
319
320 /* Initialize variables in an options structure. */
321 void (*init_options_struct) (struct gcc_options *opts);
322
323 /* After the initialize_diagnostics hook is called, do any simple
324 initialization needed before any calls to handle_option, other
325 than that done by the init_options_struct hook. */
326 void (*init_options) (unsigned int decoded_options_count,
327 struct cl_decoded_option *decoded_options);
328
329 /* Callback used to perform language-specific initialization for the
330 global diagnostic context structure. */
331 void (*initialize_diagnostics) (diagnostic_context *);
332
333 /* Register language-specific dumps. */
334 void (*register_dumps) (gcc::dump_manager *);
335
336 /* Return true if a warning should be given about option OPTION,
337 which is for the wrong language, false if it should be quietly
338 ignored. */
339 bool (*complain_wrong_lang_p) (const struct cl_option *option);
340
341 /* Handle the switch CODE, which has real type enum opt_code from
342 options.h. If the switch takes an argument, it is passed in ARG
343 which points to permanent storage. The handler is responsible for
344 checking whether ARG is NULL, which indicates that no argument
345 was in fact supplied. For -f and -W switches, VALUE is 1 or 0
346 for the positive and negative forms respectively. HANDLERS should
347 be passed to any recursive handle_option calls. LOC is the
348 location of the option.
349
350 Return true if the switch is valid, false if invalid. */
351 bool (*handle_option) (size_t code, const char *arg, int value, int kind,
352 location_t loc,
353 const struct cl_option_handlers *handlers);
354
355 /* Called when all command line options have been parsed to allow
356 further processing and initialization
357
358 Should return true to indicate that a compiler back-end is
359 not required, such as with the -E option.
360
361 If errorcount is nonzero after this call the compiler exits
362 immediately and the finish hook is not called. */
363 bool (*post_options) (const char **);
364
365 /* Called after post_options to initialize the front end. Return
366 false to indicate that no further compilation be performed, in
367 which case the finish hook is called immediately. */
368 bool (*init) (void);
369
370 /* Called at the end of compilation, as a finalizer. */
371 void (*finish) (void);
372
373 /* Parses the entire file. */
374 void (*parse_file) (void);
375
376 /* Determines if it's ok for a function to have no noreturn attribute. */
377 bool (*missing_noreturn_ok_p) (tree);
378
379 /* Called to obtain the alias set to be used for an expression or type.
380 Returns -1 if the language does nothing special for it. */
381 alias_set_type (*get_alias_set) (tree);
382
383 /* Function to finish handling an incomplete decl at the end of
384 compilation. Default hook is does nothing. */
385 void (*finish_incomplete_decl) (tree);
386
387 /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
388 DECL_NODE with a newly GC-allocated copy. */
389 void (*dup_lang_specific_decl) (tree);
390
391 /* Set the DECL_ASSEMBLER_NAME for a node. If it is the sort of
392 thing that the assembler should talk about, set
393 DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
394 Otherwise, set it to the ERROR_MARK_NODE to ensure that the
395 assembler does not talk about it. */
396 void (*set_decl_assembler_name) (tree);
397
398 /* Overwrite the DECL_ASSEMBLER_NAME for a node. The name is being
399 changed (including to or from NULL_TREE). */
400 void (*overwrite_decl_assembler_name) (tree, tree);
401
402 /* The front end can add its own statistics to -fmem-report with
403 this hook. It should output to stderr. */
404 void (*print_statistics) (void);
405
406 /* Called by print_tree when there is a tree of class tcc_exceptional
407 that it doesn't know how to display. */
408 lang_print_tree_hook print_xnode;
409
410 /* Called to print language-dependent parts of tcc_decl, tcc_type,
411 and IDENTIFIER_NODE nodes. */
412 lang_print_tree_hook print_decl;
413 lang_print_tree_hook print_type;
414 lang_print_tree_hook print_identifier;
415
416 /* Computes the name to use to print a declaration. DECL is the
417 non-NULL declaration in question. VERBOSITY determines what
418 information will be printed: 0: DECL_NAME, demangled as
419 necessary. 1: and scope information. 2: and any other
420 information that might be interesting, such as function parameter
421 types in C++. The name is in the internal character set and
422 needs to be converted to the locale character set of diagnostics,
423 or to the execution character set for strings such as
424 __PRETTY_FUNCTION__. */
425 const char *(*decl_printable_name) (tree decl, int verbosity);
426
427 /* Computes the dwarf-2/3 name for a tree. VERBOSITY determines what
428 information will be printed: 0: DECL_NAME, demangled as
429 necessary. 1: and scope information. */
430 const char *(*dwarf_name) (tree, int verbosity);
431
432 /* This compares two types for equivalence ("compatible" in C-based languages).
433 This routine should only return 1 if it is sure. It should not be used
434 in contexts where erroneously returning 0 causes problems. */
435 int (*types_compatible_p) (tree x, tree y);
436
437 /* Called by report_error_function to print out function name. */
438 void (*print_error_function) (diagnostic_context *, const char *,
439 struct diagnostic_info *);
440
441 /* Convert a character from the host's to the target's character
442 set. The character should be in what C calls the "basic source
443 character set" (roughly, the set of characters defined by plain
444 old ASCII). The default is to return the character unchanged,
445 which is correct in most circumstances. Note that both argument
446 and result should be sign-extended under -fsigned-char,
447 zero-extended under -fno-signed-char. */
448 HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
449
450 /* Pointers to machine-independent attribute tables, for front ends
451 using attribs.c. If one is NULL, it is ignored. Respectively, a
452 table of attributes specific to the language, a table of
453 attributes common to two or more languages (to allow easy
454 sharing), and a table of attributes for checking formats. */
455 const struct attribute_spec *attribute_table;
456 const struct attribute_spec *common_attribute_table;
457 const struct attribute_spec *format_attribute_table;
458
459 struct lang_hooks_for_tree_inlining tree_inlining;
460
461 struct lang_hooks_for_tree_dump tree_dump;
462
463 struct lang_hooks_for_decls decls;
464
465 struct lang_hooks_for_types types;
466
467 struct lang_hooks_for_lto lto;
468
469 /* Returns a TREE_VEC of the generic parameters of an instantiation of
470 a generic type or decl, e.g. C++ template instantiation. If
471 TREE_CHAIN of the return value is set, it is an INTEGER_CST
472 indicating how many of the elements are non-default. */
473 tree (*get_innermost_generic_parms) (const_tree);
474
475 /* Returns the TREE_VEC of arguments of an instantiation
476 of a generic type of decl, e.g. C++ template instantiation. */
477 tree (*get_innermost_generic_args) (const_tree);
478
479 /* Determine if a tree is a function parameter pack. */
480 bool (*function_parameter_pack_p) (const_tree);
481
482 /* Perform language-specific gimplification on the argument. Returns an
483 enum gimplify_status, though we can't see that type here. */
484 int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
485
486 /* Do language specific processing in the builtin function DECL */
487 tree (*builtin_function) (tree decl);
488
489 /* Like builtin_function, but make sure the scope is the external scope.
490 This is used to delay putting in back end builtin functions until the ISA
491 that defines the builtin is declared via function specific target options,
492 which can save memory for machines like the x86_64 that have multiple
493 ISAs. If this points to the same function as builtin_function, the
494 backend must add all of the builtins at program initialization time. */
495 tree (*builtin_function_ext_scope) (tree decl);
496
497 /* Used to set up the tree_contains_structure array for a frontend. */
498 void (*init_ts) (void);
499
500 /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
501 to a contained expression or DECL, possibly updating *TC or *SE
502 if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating. */
503 tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
504
505 /* The EH personality function decl. */
506 tree (*eh_personality) (void);
507
508 /* Map a type to a runtime object to match type. */
509 tree (*eh_runtime_type) (tree);
510
511 /* If non-NULL, this is a function that returns a function decl to be
512 executed if an unhandled exception is propagated out of a cleanup
513 region. For example, in C++, an exception thrown by a destructor
514 during stack unwinding is required to result in a call to
515 `std::terminate', so the C++ version of this function returns a
516 FUNCTION_DECL for `std::terminate'. */
517 tree (*eh_protect_cleanup_actions) (void);
518
519 /* Return true if a stmt can fallthru. Used by block_may_fallthru
520 to possibly handle language trees. */
521 bool (*block_may_fallthru) (const_tree);
522
523 /* True if this language uses __cxa_end_cleanup when the ARM EABI
524 is enabled. */
525 bool eh_use_cxa_end_cleanup;
526
527 /* True if this language requires deep unsharing of tree nodes prior to
528 gimplification. */
529 bool deep_unsharing;
530
531 /* True if this language may use custom descriptors for nested functions
532 instead of trampolines. */
533 bool custom_function_descriptors;
534
535 /* True if this language emits begin stmt notes. */
536 bool emits_begin_stmt;
537
538 /* Run all lang-specific selftests. */
539 void (*run_lang_selftests) (void);
540
541 /* Attempt to determine the source location of the substring.
542 If successful, return NULL and write the source location to *OUT_LOC.
543 Otherwise return an error message. Error messages are intended
544 for GCC developers (to help debugging) rather than for end-users. */
545 const char *(*get_substring_location) (const substring_loc &,
546 location_t *out_loc);
547
548 /* Whenever you add entries here, make sure you adjust langhooks-def.h
549 and langhooks.c accordingly. */
550};
551
552/* Each front end provides its own. */
553extern struct lang_hooks lang_hooks;
554
555extern tree add_builtin_function (const char *name, tree type,
556 int function_code, enum built_in_class cl,
557 const char *library_name,
558 tree attrs);
559
560extern tree add_builtin_function_ext_scope (const char *name, tree type,
561 int function_code,
562 enum built_in_class cl,
563 const char *library_name,
564 tree attrs);
565extern tree add_builtin_type (const char *name, tree type);
566
567/* Language helper functions. */
568
569extern bool lang_GNU_C (void);
570extern bool lang_GNU_CXX (void);
571extern bool lang_GNU_Fortran (void);
572extern bool lang_GNU_OBJC (void);
573
574#endif /* GCC_LANG_HOOKS_H */
575