gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright (C) 2001-2016 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 /* The following hooks are documented in langhooks.c.  Must not be
  38    NULL.  */
  39
  40 struct lang_hooks_for_tree_inlining
  41 {
  42   bool (*var_mod_type_p) (tree, tree);
  43 };
  44
  45 /* The following hooks are used by tree-dump.c.  */
  46
  47 struct lang_hooks_for_tree_dump
  48 {
  49   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  50      does not want the usual dumping of the second argument.  */
  51   bool (*dump_tree) (void *, tree);
  52
  53   /* Determine type qualifiers in a language-specific way.  */
  54   int (*type_quals) (const_tree);
  55 };
  56
  57 /* Hooks related to types.  */
  58
  59 struct lang_hooks_for_types
  60 {
  61   /* Return a new type (with the indicated CODE), doing whatever
  62      language-specific processing is required.  */
  63   tree (*make_type) (enum tree_code);
  64
  65   /* Return what kind of RECORD_TYPE this is, mainly for purposes of
  66      debug information.  If not defined, record types are assumed to
  67      be structures.  */
  68   enum classify_record (*classify_record) (tree);
  69
  70   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  71      mode.  */
  72   tree (*type_for_mode) (machine_mode, int);
  73
  74   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
  75      integer type with at least that precision.  */
  76   tree (*type_for_size) (unsigned, int);
  77
  78   /* True if the type is an instantiation of a generic type,
  79      e.g. C++ template implicit specializations.  */
  80   bool (*generic_p) (const_tree);
  81
  82   /* Returns the TREE_VEC of elements of a given generic argument pack.  */
  83   tree (*get_argument_pack_elems) (const_tree);
  84
  85   /* Given a type, apply default promotions to unnamed function
  86      arguments and return the new type.  Return the same type if no
  87      change.  Required by any language that supports variadic
  88      arguments.  The default hook dies.  */
  89   tree (*type_promotes_to) (tree);
  90
  91   /* Register TYPE as a builtin type with the indicated NAME.  The
  92      TYPE is placed in the outermost lexical scope.  The semantics
  93      should be analogous to:
  94
  95        typedef TYPE NAME;
  96
  97      in C.  The default hook ignores the declaration.  */
  98   void (*register_builtin_type) (tree, const char *);
  99
 100   /* This routine is called in tree.c to print an error message for
 101      invalid use of an incomplete type.  VALUE is the expression that
 102      was used (or 0 if that isn't known) and TYPE is the type that was
 103      invalid.  */
 104   void (*incomplete_type_error) (const_tree value, const_tree type);
 105
 106   /* Called from assign_temp to return the maximum size, if there is one,
 107      for a type.  */
 108   tree (*max_size) (const_tree);
 109
 110   /* Register language specific type size variables as potentially OpenMP
 111      firstprivate variables.  */
 112   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 113
 114   /* Return true if TYPE is a mappable type.  */
 115   bool (*omp_mappable_type) (tree type);
 116
 117   /* Return TRUE if TYPE1 and TYPE2 are identical for type hashing purposes.
 118      Called only after doing all language independent checks.
 119      At present, this function is only called when both TYPE1 and TYPE2 are
 120      FUNCTION_TYPEs.  */
 121   bool (*type_hash_eq) (const_tree, const_tree);
 122
 123   /* Return TRUE if TYPE uses a hidden descriptor and fills in information
 124      for the debugger about the array bounds, strides, etc.  */
 125   bool (*get_array_descr_info) (const_tree, struct array_descr_info *);
 126
 127   /* Fill in information for the debugger about the bounds of TYPE.  */
 128   void (*get_subrange_bounds) (const_tree, tree *, tree *);
 129
 130   /* Called on INTEGER_TYPEs.  Return NULL_TREE for non-biased types.  For
 131      biased types, return as an INTEGER_CST node the value that is represented
 132      by a physical zero.  */
 133   tree (*get_type_bias) (const_tree);
 134
 135   /* A type descriptive of TYPE's complex layout generated to help the
 136      debugger to decode variable-length or self-referential constructs.
 137      This is only used for the AT_GNAT_descriptive_type DWARF attribute.  */
 138   tree (*descriptive_type) (const_tree);
 139
 140   /* If we requested a pointer to a vector, build up the pointers that
 141      we stripped off while looking for the inner type.  Similarly for
 142      return values from functions.  The argument TYPE is the top of the
 143      chain, and BOTTOM is the new type which we will point to.  */
 144   tree (*reconstruct_complex_type) (tree, tree);
 145
 146   /* Returns the tree that represents the underlying data type used to
 147      implement the enumeration.  The default implementation will just use
 148      type_for_size.  Used in dwarf2out.c to add a DW_AT_type base type
 149      reference to a DW_TAG_enumeration.  */
 150   tree (*enum_underlying_base_type) (const_tree);
 151
 152   /* Return a type to use in the debug info instead of TYPE, or NULL_TREE to
 153      keep TYPE.  This is useful to keep a single "source type" when the
 154      middle-end uses specialized types, for instance constrained discriminated
 155      types in Ada.  */
 156   tree (*get_debug_type) (const_tree);
 157
 158   /* Return TRUE if TYPE implements a fixed point type and fills in information
 159      for the debugger about scale factor, etc.  */
 160   bool (*get_fixed_point_type_info) (const_tree,
 161                                      struct fixed_point_type_info *);
 162 };
 163
 164 /* Language hooks related to decls and the symbol table.  */
 165
 166 struct lang_hooks_for_decls
 167 {
 168   /* Return true if we are in the global binding level.  This hook is really
 169      needed only if the language supports variable-sized types at the global
 170      level, i.e. declared outside subprograms.  */
 171   bool (*global_bindings_p) (void);
 172
 173   /* Function to add a decl to the current scope level.  Takes one
 174      argument, a decl to add.  Returns that decl, or, if the same
 175      symbol is already declared, may return a different decl for that
 176      name.  */
 177   tree (*pushdecl) (tree);
 178
 179   /* Returns the chain of decls so far in the current scope level.  */
 180   tree (*getdecls) (void);
 181
 182   /* Returns true if DECL is explicit member function.  */
 183   bool (*function_decl_explicit_p) (tree);
 184
 185   /* Returns true if DECL is C++11 deleted special member function.  */
 186   bool (*function_decl_deleted_p) (tree);
 187
 188   /* Returns True if the parameter is a generic parameter decl
 189      of a generic type, e.g a template template parameter for the C++ FE.  */
 190   bool (*generic_generic_parameter_decl_p) (const_tree);
 191
 192   /* Determine if a function parameter got expanded from a
 193      function parameter pack.  */
 194   bool (*function_parm_expanded_from_pack_p) (tree, tree);
 195
 196   /* Returns the generic declaration of a generic function instantiations.  */
 197   tree (*get_generic_function_decl) (const_tree);
 198
 199   /* Returns true when we should warn for an unused global DECL.
 200      We will already have checked that it has static binding.  */
 201   bool (*warn_unused_global) (const_tree);
 202
 203   /* Perform any post compilation-proper parser cleanups and
 204      processing.  This is currently only needed for the C++ parser,
 205      which hopefully can be cleaned up so this hook is no longer
 206      necessary.  */
 207   void (*post_compilation_parsing_cleanups) (void);
 208
 209   /* True if this decl may be called via a sibcall.  */
 210   bool (*ok_for_sibcall) (const_tree);
 211
 212   /* True if OpenMP should privatize what this DECL points to rather
 213      than the DECL itself.  */
 214   bool (*omp_privatize_by_reference) (const_tree);
 215
 216   /* Return sharing kind if OpenMP sharing attribute of DECL is
 217      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 218   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 219
 220   /* Return decl that should be reported for DEFAULT(NONE) failure
 221      diagnostics.  Usually the DECL passed in.  */
 222   tree (*omp_report_decl) (tree);
 223
 224   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 225      disregarded in OpenMP construct, because it is going to be
 226      remapped during OpenMP lowering.  SHARED is true if DECL
 227      is going to be shared, false if it is going to be privatized.  */
 228   bool (*omp_disregard_value_expr) (tree, bool);
 229
 230   /* Return true if DECL that is shared iff SHARED is true should
 231      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 232   bool (*omp_private_debug_clause) (tree, bool);
 233
 234   /* Return true if DECL in private clause needs
 235      OMP_CLAUSE_PRIVATE_OUTER_REF on the private clause.  */
 236   bool (*omp_private_outer_ref) (tree);
 237
 238   /* Build and return code for a default constructor for DECL in
 239      response to CLAUSE.  OUTER is corresponding outer region's
 240      variable if needed.  Return NULL if nothing to be done.  */
 241   tree (*omp_clause_default_ctor) (tree clause, tree decl, tree outer);
 242
 243   /* Build and return code for a copy constructor from SRC to DST.  */
 244   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 245
 246   /* Similarly, except use an assignment operator instead.  */
 247   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 248
 249   /* Build and return code for a constructor of DST that sets it to
 250      SRC + ADD.  */
 251   tree (*omp_clause_linear_ctor) (tree clause, tree dst, tree src, tree add);
 252
 253   /* Build and return code destructing DECL.  Return NULL if nothing
 254      to be done.  */
 255   tree (*omp_clause_dtor) (tree clause, tree decl);
 256
 257   /* Do language specific checking on an implicitly determined clause.  */
 258   void (*omp_finish_clause) (tree clause, gimple_seq *pre_p);
 259 };
 260
 261 /* Language hooks related to LTO serialization.  */
 262
 263 struct lang_hooks_for_lto
 264 {
 265   /* Begin a new LTO section named NAME.  */
 266   void (*begin_section) (const char *name);
 267
 268   /* Write DATA of length LEN to the currently open LTO section.  BLOCK is a
 269      pointer to the dynamically allocated memory containing DATA.  The
 270      append_data function is responsible for freeing it when it is no longer
 271      needed.  */
 272   void (*append_data) (const void *data, size_t len, void *block);
 273
 274   /* End the previously begun LTO section.  */
 275   void (*end_section) (void);
 276 };
 277
 278 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 279
 280 struct lang_hooks
 281 {
 282   /* String identifying the front end and optionally language standard
 283      version, e.g. "GNU C++98" or "GNU Java".  */
 284   const char *name;
 285
 286   /* sizeof (struct lang_identifier), so make_node () creates
 287      identifier nodes long enough for the language-specific slots.  */
 288   size_t identifier_size;
 289
 290   /* Remove any parts of the tree that are used only by the FE. */
 291   void (*free_lang_data) (tree);
 292
 293   /* Determines the size of any language-specific tcc_constant or
 294      tcc_exceptional nodes.  Since it is called from make_node, the
 295      only information available is the tree code.  Expected to die
 296      on unrecognized codes.  */
 297   size_t (*tree_size) (enum tree_code);
 298
 299   /* Return the language mask used for converting argv into a sequence
 300      of options.  */
 301   unsigned int (*option_lang_mask) (void);
 302
 303   /* Initialize variables in an options structure.  */
 304   void (*init_options_struct) (struct gcc_options *opts);
 305
 306   /* After the initialize_diagnostics hook is called, do any simple
 307      initialization needed before any calls to handle_option, other
 308      than that done by the init_options_struct hook.  */
 309   void (*init_options) (unsigned int decoded_options_count,
 310                         struct cl_decoded_option *decoded_options);
 311
 312   /* Callback used to perform language-specific initialization for the
 313      global diagnostic context structure.  */
 314   void (*initialize_diagnostics) (diagnostic_context *);
 315
 316   /* Return true if a warning should be given about option OPTION,
 317      which is for the wrong language, false if it should be quietly
 318      ignored.  */
 319   bool (*complain_wrong_lang_p) (const struct cl_option *option);
 320
 321   /* Handle the switch CODE, which has real type enum opt_code from
 322      options.h.  If the switch takes an argument, it is passed in ARG
 323      which points to permanent storage.  The handler is responsible for
 324      checking whether ARG is NULL, which indicates that no argument
 325      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 326      for the positive and negative forms respectively.  HANDLERS should
 327      be passed to any recursive handle_option calls.  LOC is the
 328      location of the option.
 329
 330      Return true if the switch is valid, false if invalid.  */
 331   bool (*handle_option) (size_t code, const char *arg, int value, int kind,
 332                          location_t loc,
 333                          const struct cl_option_handlers *handlers);
 334
 335   /* Called when all command line options have been parsed to allow
 336      further processing and initialization
 337
 338      Should return true to indicate that a compiler back-end is
 339      not required, such as with the -E option.
 340
 341      If errorcount is nonzero after this call the compiler exits
 342      immediately and the finish hook is not called.  */
 343   bool (*post_options) (const char **);
 344
 345   /* Called after post_options to initialize the front end.  Return
 346      false to indicate that no further compilation be performed, in
 347      which case the finish hook is called immediately.  */
 348   bool (*init) (void);
 349
 350   /* Called at the end of compilation, as a finalizer.  */
 351   void (*finish) (void);
 352
 353   /* Parses the entire file.  */
 354   void (*parse_file) (void);
 355
 356   /* Determines if it's ok for a function to have no noreturn attribute.  */
 357   bool (*missing_noreturn_ok_p) (tree);
 358
 359   /* Called to obtain the alias set to be used for an expression or type.
 360      Returns -1 if the language does nothing special for it.  */
 361   alias_set_type (*get_alias_set) (tree);
 362
 363   /* Function to finish handling an incomplete decl at the end of
 364      compilation.  Default hook is does nothing.  */
 365   void (*finish_incomplete_decl) (tree);
 366
 367   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 368      DECL_NODE with a newly GC-allocated copy.  */
 369   void (*dup_lang_specific_decl) (tree);
 370
 371   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 372      thing that the assembler should talk about, set
 373      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 374      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 375      assembler does not talk about it.  */
 376   void (*set_decl_assembler_name) (tree);
 377
 378   /* The front end can add its own statistics to -fmem-report with
 379      this hook.  It should output to stderr.  */
 380   void (*print_statistics) (void);
 381
 382   /* Called by print_tree when there is a tree of class tcc_exceptional
 383      that it doesn't know how to display.  */
 384   lang_print_tree_hook print_xnode;
 385
 386   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 387      and IDENTIFIER_NODE nodes.  */
 388   lang_print_tree_hook print_decl;
 389   lang_print_tree_hook print_type;
 390   lang_print_tree_hook print_identifier;
 391
 392   /* Computes the name to use to print a declaration.  DECL is the
 393      non-NULL declaration in question.  VERBOSITY determines what
 394      information will be printed: 0: DECL_NAME, demangled as
 395      necessary.  1: and scope information.  2: and any other
 396      information that might be interesting, such as function parameter
 397      types in C++.  The name is in the internal character set and
 398      needs to be converted to the locale character set of diagnostics,
 399      or to the execution character set for strings such as
 400      __PRETTY_FUNCTION__.  */
 401   const char *(*decl_printable_name) (tree decl, int verbosity);
 402
 403   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 404      information will be printed: 0: DECL_NAME, demangled as
 405      necessary.  1: and scope information.  */
 406   const char *(*dwarf_name) (tree, int verbosity);
 407
 408   /* This compares two types for equivalence ("compatible" in C-based languages).
 409      This routine should only return 1 if it is sure.  It should not be used
 410      in contexts where erroneously returning 0 causes problems.  */
 411   int (*types_compatible_p) (tree x, tree y);
 412
 413   /* Called by report_error_function to print out function name.  */
 414   void (*print_error_function) (diagnostic_context *, const char *,
 415                                 struct diagnostic_info *);
 416
 417   /* Convert a character from the host's to the target's character
 418      set.  The character should be in what C calls the "basic source
 419      character set" (roughly, the set of characters defined by plain
 420      old ASCII).  The default is to return the character unchanged,
 421      which is correct in most circumstances.  Note that both argument
 422      and result should be sign-extended under -fsigned-char,
 423      zero-extended under -fno-signed-char.  */
 424   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 425
 426   /* Pointers to machine-independent attribute tables, for front ends
 427      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 428      table of attributes specific to the language, a table of
 429      attributes common to two or more languages (to allow easy
 430      sharing), and a table of attributes for checking formats.  */
 431   const struct attribute_spec *attribute_table;
 432   const struct attribute_spec *common_attribute_table;
 433   const struct attribute_spec *format_attribute_table;
 434
 435   struct lang_hooks_for_tree_inlining tree_inlining;
 436
 437   struct lang_hooks_for_tree_dump tree_dump;
 438
 439   struct lang_hooks_for_decls decls;
 440
 441   struct lang_hooks_for_types types;
 442
 443   struct lang_hooks_for_lto lto;
 444
 445   /* Returns a TREE_VEC of the generic parameters of an instantiation of
 446      a generic type or decl, e.g. C++ template instantiation.  If
 447      TREE_CHAIN of the return value is set, it is an INTEGER_CST
 448      indicating how many of the elements are non-default.  */
 449   tree (*get_innermost_generic_parms) (const_tree);
 450
 451   /* Returns the TREE_VEC of arguments of an instantiation
 452      of a generic type of decl, e.g. C++ template instantiation.  */
 453   tree (*get_innermost_generic_args) (const_tree);
 454
 455   /* Determine if a tree is a function parameter pack.  */
 456   bool (*function_parameter_pack_p) (const_tree);
 457
 458   /* Perform language-specific gimplification on the argument.  Returns an
 459      enum gimplify_status, though we can't see that type here.  */
 460   int (*gimplify_expr) (tree *, gimple_seq *, gimple_seq *);
 461
 462   /* Do language specific processing in the builtin function DECL  */
 463   tree (*builtin_function) (tree decl);
 464
 465   /* Like builtin_function, but make sure the scope is the external scope.
 466      This is used to delay putting in back end builtin functions until the ISA
 467      that defines the builtin is declared via function specific target options,
 468      which can save memory for machines like the x86_64 that have multiple
 469      ISAs.  If this points to the same function as builtin_function, the
 470      backend must add all of the builtins at program initialization time.  */
 471   tree (*builtin_function_ext_scope) (tree decl);
 472
 473   /* Used to set up the tree_contains_structure array for a frontend. */
 474   void (*init_ts) (void);
 475
 476   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 477      to a contained expression or DECL, possibly updating *TC or *SE
 478      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
 479   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 480
 481   /* The EH personality function decl.  */
 482   tree (*eh_personality) (void);
 483
 484   /* Map a type to a runtime object to match type.  */
 485   tree (*eh_runtime_type) (tree);
 486
 487   /* If non-NULL, this is a function that returns a function decl to be
 488      executed if an unhandled exception is propagated out of a cleanup
 489      region.  For example, in C++, an exception thrown by a destructor
 490      during stack unwinding is required to result in a call to
 491      `std::terminate', so the C++ version of this function returns a
 492      FUNCTION_DECL for `std::terminate'.  */
 493   tree (*eh_protect_cleanup_actions) (void);
 494
 495   /* Return true if a stmt can fallthru.  Used by block_may_fallthru
 496      to possibly handle language trees.  */
 497   bool (*block_may_fallthru) (const_tree);
 498
 499   /* True if this language uses __cxa_end_cleanup when the ARM EABI
 500      is enabled.  */
 501   bool eh_use_cxa_end_cleanup;
 502
 503   /* True if this language requires deep unsharing of tree nodes prior to
 504      gimplification.  */
 505   bool deep_unsharing;
 506
 507   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 508      and langhooks.c accordingly.  */
 509 };
 510
 511 /* Each front end provides its own.  */
 512 extern struct lang_hooks lang_hooks;
 513
 514 extern tree add_builtin_function (const char *name, tree type,
 515                                   int function_code, enum built_in_class cl,
 516                                   const char *library_name,
 517                                   tree attrs);
 518
 519 extern tree add_builtin_function_ext_scope (const char *name, tree type,
 520                                             int function_code,
 521                                             enum built_in_class cl,
 522                                             const char *library_name,
 523                                             tree attrs);
 524 extern tree add_builtin_type (const char *name, tree type);
 525
 526 /* Language helper functions.  */
 527
 528 extern bool lang_GNU_C (void);
 529 extern bool lang_GNU_CXX (void);
 530 extern bool lang_GNU_Fortran (void);
 531
 532 #endif /* GCC_LANG_HOOKS_H */