1 /* The lang_hooks data structure. 2 Copyright (C) 2001-2018 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.c. 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.c. */ 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 /* 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. */ 180 181 struct 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. */ 279 280 struct 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. */ 296 297 struct 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. */ 553 extern struct lang_hooks lang_hooks; 554 555 extern 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); 559 560 extern 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); 565 extern tree add_builtin_type (const char *name, tree type); 566 567 /* Language helper functions. */ 568 569 extern bool lang_GNU_C (void); 570 extern bool lang_GNU_CXX (void); 571 extern bool lang_GNU_Fortran (void); 572 extern bool lang_GNU_OBJC (void); 573 574 #endif /* GCC_LANG_HOOKS_H */ 575