1 /* The lang_hooks data structure. 2 Copyright (C) 2001-2017 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" or "GNU Java". */ 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 or 311 tcc_exceptional nodes. Since it is called from make_node, the 312 only information available is the tree code. Expected to die 313 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 /* Return true if a warning should be given about option OPTION, 334 which is for the wrong language, false if it should be quietly 335 ignored. */ 336 bool (*complain_wrong_lang_p) (const struct cl_option *option); 337 338 /* Handle the switch CODE, which has real type enum opt_code from 339 options.h. If the switch takes an argument, it is passed in ARG 340 which points to permanent storage. The handler is responsible for 341 checking whether ARG is NULL, which indicates that no argument 342 was in fact supplied. For -f and -W switches, VALUE is 1 or 0 343 for the positive and negative forms respectively. HANDLERS should 344 be passed to any recursive handle_option calls. LOC is the 345 location of the option. 346 347 Return true if the switch is valid, false if invalid. */ 348 bool (*handle_option) (size_t code, const char *arg, int value, int kind, 349 location_t loc, 350 const struct cl_option_handlers *handlers); 351 352 /* Called when all command line options have been parsed to allow 353 further processing and initialization 354 355 Should return true to indicate that a compiler back-end is 356 not required, such as with the -E option. 357 358 If errorcount is nonzero after this call the compiler exits 359 immediately and the finish hook is not called. */ 360 bool (*post_options) (const char **); 361 362 /* Called after post_options to initialize the front end. Return 363 false to indicate that no further compilation be performed, in 364 which case the finish hook is called immediately. */ 365 bool (*init) (void); 366 367 /* Called at the end of compilation, as a finalizer. */ 368 void (*finish) (void); 369 370 /* Parses the entire file. */ 371 void (*parse_file) (void); 372 373 /* Determines if it's ok for a function to have no noreturn attribute. */ 374 bool (*missing_noreturn_ok_p) (tree); 375 376 /* Called to obtain the alias set to be used for an expression or type. 377 Returns -1 if the language does nothing special for it. */ 378 alias_set_type (*get_alias_set) (tree); 379 380 /* Function to finish handling an incomplete decl at the end of 381 compilation. Default hook is does nothing. */ 382 void (*finish_incomplete_decl) (tree); 383 384 /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the 385 DECL_NODE with a newly GC-allocated copy. */ 386 void (*dup_lang_specific_decl) (tree); 387 388 /* Set the DECL_ASSEMBLER_NAME for a node. If it is the sort of 389 thing that the assembler should talk about, set 390 DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE. 391 Otherwise, set it to the ERROR_MARK_NODE to ensure that the 392 assembler does not talk about it. */ 393 void (*set_decl_assembler_name) (tree); 394 395 /* The front end can add its own statistics to -fmem-report with 396 this hook. It should output to stderr. */ 397 void (*print_statistics) (void); 398 399 /* Called by print_tree when there is a tree of class tcc_exceptional 400 that it doesn't know how to display. */ 401 lang_print_tree_hook print_xnode; 402 403 /* Called to print language-dependent parts of tcc_decl, tcc_type, 404 and IDENTIFIER_NODE nodes. */ 405 lang_print_tree_hook print_decl; 406 lang_print_tree_hook print_type; 407 lang_print_tree_hook print_identifier; 408 409 /* Computes the name to use to print a declaration. DECL is the 410 non-NULL declaration in question. VERBOSITY determines what 411 information will be printed: 0: DECL_NAME, demangled as 412 necessary. 1: and scope information. 2: and any other 413 information that might be interesting, such as function parameter 414 types in C++. The name is in the internal character set and 415 needs to be converted to the locale character set of diagnostics, 416 or to the execution character set for strings such as 417 __PRETTY_FUNCTION__. */ 418 const char *(*decl_printable_name) (tree decl, int verbosity); 419 420 /* Computes the dwarf-2/3 name for a tree. VERBOSITY determines what 421 information will be printed: 0: DECL_NAME, demangled as 422 necessary. 1: and scope information. */ 423 const char *(*dwarf_name) (tree, int verbosity); 424 425 /* This compares two types for equivalence ("compatible" in C-based languages). 426 This routine should only return 1 if it is sure. It should not be used 427 in contexts where erroneously returning 0 causes problems. */ 428 int (*types_compatible_p) (tree x, tree y); 429 430 /* Called by report_error_function to print out function name. */ 431 void (*print_error_function) (diagnostic_context *, const char *, 432 struct diagnostic_info *); 433 434 /* Convert a character from the host's to the target's character 435 set. The character should be in what C calls the "basic source 436 character set" (roughly, the set of characters defined by plain 437 old ASCII). The default is to return the character unchanged, 438 which is correct in most circumstances. Note that both argument 439 and result should be sign-extended under -fsigned-char, 440 zero-extended under -fno-signed-char. */ 441 HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT); 442 443 /* Pointers to machine-independent attribute tables, for front ends 444 using attribs.c. If one is NULL, it is ignored. Respectively, a 445 table of attributes specific to the language, a table of 446 attributes common to two or more languages (to allow easy 447 sharing), and a table of attributes for checking formats. */ 448 const struct attribute_spec *attribute_table; 449 const struct attribute_spec *common_attribute_table; 450 const struct attribute_spec *format_attribute_table; 451 452 struct lang_hooks_for_tree_inlining tree_inlining; 453 454 struct lang_hooks_for_tree_dump tree_dump; 455 456 struct lang_hooks_for_decls decls; 457 458 struct lang_hooks_for_types types; 459 460 struct lang_hooks_for_lto lto; 461 462 /* Returns a TREE_VEC of the generic parameters of an instantiation of 463 a generic type or decl, e.g. C++ template instantiation. If 464 TREE_CHAIN of the return value is set, it is an INTEGER_CST 465 indicating how many of the elements are non-default. */ 466 tree (*get_innermost_generic_parms) (const_tree); 467 468 /* Returns the TREE_VEC of arguments of an instantiation 469 of a generic type of decl, e.g. C++ template instantiation. */ 470 tree (*get_innermost_generic_args) (const_tree); 471 472 /* Determine if a tree is a function parameter pack. */ 473 bool (*function_parameter_pack_p) (const_tree); 474 475 /* Perform language-specific gimplification on the argument. Returns an 476 enum gimplify_status, though we can't see that type here. */ 477 int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *); 478 479 /* Do language specific processing in the builtin function DECL */ 480 tree (*builtin_function) (tree decl); 481 482 /* Like builtin_function, but make sure the scope is the external scope. 483 This is used to delay putting in back end builtin functions until the ISA 484 that defines the builtin is declared via function specific target options, 485 which can save memory for machines like the x86_64 that have multiple 486 ISAs. If this points to the same function as builtin_function, the 487 backend must add all of the builtins at program initialization time. */ 488 tree (*builtin_function_ext_scope) (tree decl); 489 490 /* Used to set up the tree_contains_structure array for a frontend. */ 491 void (*init_ts) (void); 492 493 /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR 494 to a contained expression or DECL, possibly updating *TC or *SE 495 if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating. */ 496 tree (*expr_to_decl) (tree expr, bool *tc, bool *se); 497 498 /* The EH personality function decl. */ 499 tree (*eh_personality) (void); 500 501 /* Map a type to a runtime object to match type. */ 502 tree (*eh_runtime_type) (tree); 503 504 /* If non-NULL, this is a function that returns a function decl to be 505 executed if an unhandled exception is propagated out of a cleanup 506 region. For example, in C++, an exception thrown by a destructor 507 during stack unwinding is required to result in a call to 508 `std::terminate', so the C++ version of this function returns a 509 FUNCTION_DECL for `std::terminate'. */ 510 tree (*eh_protect_cleanup_actions) (void); 511 512 /* Return true if a stmt can fallthru. Used by block_may_fallthru 513 to possibly handle language trees. */ 514 bool (*block_may_fallthru) (const_tree); 515 516 /* True if this language uses __cxa_end_cleanup when the ARM EABI 517 is enabled. */ 518 bool eh_use_cxa_end_cleanup; 519 520 /* True if this language requires deep unsharing of tree nodes prior to 521 gimplification. */ 522 bool deep_unsharing; 523 524 /* True if this language may use custom descriptors for nested functions 525 instead of trampolines. */ 526 bool custom_function_descriptors; 527 528 /* Run all lang-specific selftests. */ 529 void (*run_lang_selftests) (void); 530 531 /* Attempt to determine the source location of the substring. 532 If successful, return NULL and write the source location to *OUT_LOC. 533 Otherwise return an error message. Error messages are intended 534 for GCC developers (to help debugging) rather than for end-users. */ 535 const char *(*get_substring_location) (const substring_loc &, 536 location_t *out_loc); 537 538 /* Whenever you add entries here, make sure you adjust langhooks-def.h 539 and langhooks.c accordingly. */ 540 }; 541 542 /* Each front end provides its own. */ 543 extern struct lang_hooks lang_hooks; 544 545 extern tree add_builtin_function (const char *name, tree type, 546 int function_code, enum built_in_class cl, 547 const char *library_name, 548 tree attrs); 549 550 extern tree add_builtin_function_ext_scope (const char *name, tree type, 551 int function_code, 552 enum built_in_class cl, 553 const char *library_name, 554 tree attrs); 555 extern tree add_builtin_type (const char *name, tree type); 556 557 /* Language helper functions. */ 558 559 extern bool lang_GNU_C (void); 560 extern bool lang_GNU_CXX (void); 561 extern bool lang_GNU_Fortran (void); 562 extern bool lang_GNU_OBJC (void); 563 564 #endif /* GCC_LANG_HOOKS_H */ 565