gcc/ada/gcc-interface/gigi.h

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                                 G I G I                                  *
   6  *                                                                          *
   7  *                              C Header File                               *
   8  *                                                                          *
   9  *          Copyright (C) 1992-2024, Free Software Foundation, Inc.         *
  10  *                                                                          *
  11  * GNAT is free software;  you can  redistribute it  and/or modify it under *
  12  * terms of the  GNU General Public License as published  by the Free Soft- *
  13  * ware  Foundation;  either version 3,  or (at your option) any later ver- *
  14  * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
  15  * OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY *
  16  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License *
  17  * for  more details.  You should have  received  a copy of the GNU General *
  18  * Public License  distributed  with GNAT;  see file  COPYING3.  If not see *
  19  * <http://www.gnu.org/licenses/>.                                          *
  20  *                                                                          *
  21  * GNAT was originally developed  by the GNAT team at  New York University. *
  22  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  23  *                                                                          *
  24  ****************************************************************************/
  25
  26 /* Declare all functions and types used by gigi.  */
  27
  28 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
  29    entity, this routine returns the equivalent GCC tree for that entity
  30    (an ..._DECL node) and associates the ..._DECL node with the input GNAT
  31    defining identifier.
  32
  33    If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
  34    initial value (in GCC tree form). This is optional for variables.
  35    For renamed entities, GNU_EXPR gives the object being renamed.
  36
  37    DEFINITION is true if this call is intended for a definition.  This is used
  38    for separate compilation where it is necessary to know whether an external
  39    declaration or a definition must be created if the GCC equivalent was not
  40    created previously.  */
  41 extern tree gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr,
  42                                 bool definition);
  43
  44 /* Similar, but if the returned value is a COMPONENT_REF, return the
  45    FIELD_DECL.  */
  46 extern tree gnat_to_gnu_field_decl (Entity_Id gnat_entity);
  47
  48 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type.  Return
  49    the GCC type corresponding to that entity.  */
  50 extern tree gnat_to_gnu_type (Entity_Id gnat_entity);
  51
  52 /* Update the GCC tree previously built for the profiles involving GNU_TYPE,
  53    a dummy type which appears in profiles.  */
  54 extern void update_profiles_with (tree gnu_type);
  55
  56 /* Start a new statement group chained to the previous group.  */
  57 extern void start_stmt_group (void);
  58
  59 /* Add GNU_STMT to the current statement group.  If it is an expression with
  60    no effects, it is ignored.  */
  61 extern void add_stmt (tree gnu_stmt);
  62
  63 /* Similar, but the statement is always added, regardless of side-effects.  */
  64 extern void add_stmt_force (tree gnu_stmt);
  65
  66 /* Like add_stmt, but set the location of GNU_STMT to that of GNAT_NODE.  */
  67 extern void add_stmt_with_node (tree gnu_stmt, Node_Id gnat_node);
  68
  69 /* Similar, but the statement is always added, regardless of side-effects.  */
  70 extern void add_stmt_with_node_force (tree gnu_stmt, Node_Id gnat_node);
  71
  72 /* Return code corresponding to the current code group.  It is normally
  73    a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if
  74    BLOCK or cleanups were set.  */
  75 extern tree end_stmt_group (void);
  76
  77 /* Set the BLOCK node corresponding to the current code group to GNU_BLOCK.  */
  78 extern void set_block_for_group (tree);
  79
  80 /* Add a declaration statement for GNU_DECL to the current statement group.
  81    Get the SLOC to be put onto the statement from GNAT_NODE.  */
  82 extern void add_decl_expr (tree gnu_decl, Node_Id gnat_node);
  83
  84 /* Mark nodes rooted at T with TREE_VISITED and types as having their
  85    sized gimplified.  We use this to indicate all variable sizes and
  86    positions in global types may not be shared by any subprogram.  */
  87 extern void mark_visited (tree t);
  88
  89 /* This macro calls the above function but short-circuits the common
  90    case of a constant to save time and also checks for NULL.  */
  91 #define MARK_VISITED(EXP)               \
  92 do {                                    \
  93   if((EXP) && !CONSTANT_CLASS_P (EXP))  \
  94     mark_visited (EXP);                 \
  95 } while (0)
  96
  97 /* Finalize the processing of From_Limited_With incomplete types.  */
  98 extern void finalize_from_limited_with (void);
  99
 100 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a kind
 101    of type (such E_Task_Type) that has a different type which Gigi uses
 102    for its representation.  If the type does not have a special type for
 103    its representation, return GNAT_ENTITY.  */
 104 extern Entity_Id Gigi_Equivalent_Type (Entity_Id gnat_entity);
 105
 106 /* Given GNAT_ENTITY, elaborate all expressions that are required to
 107    be elaborated at the point of its definition, but do nothing else.  */
 108 extern void elaborate_entity (Entity_Id gnat_entity);
 109
 110 /* Get the unpadded version of a GNAT type.  */
 111 extern tree get_unpadded_type (Entity_Id gnat_entity);
 112
 113 /* Create a record type that contains a SIZE bytes long field of TYPE with a
 114     starting bit position so that it is aligned to ALIGN bits, and leaving at
 115     least ROOM bytes free before the field.  BASE_ALIGN is the alignment the
 116     record is guaranteed to get.  GNAT_NODE is used for the position of the
 117     associated TYPE_DECL.  */
 118 extern tree make_aligning_type (tree type, unsigned int align, tree size,
 119                                 unsigned int base_align, int room, Node_Id);
 120
 121 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
 122    as the field type of a packed record if IN_RECORD is true, or as the
 123    component type of a packed array if IN_RECORD is false.  See if we can
 124    rewrite it either as a type that has a non-BLKmode, which we can pack
 125    tighter in the packed record case, or as a smaller type with at most
 126    MAX_ALIGN alignment if the value is non-zero.  If so, return the new
 127    type; if not, return the original type.  */
 128 extern tree make_packable_type (tree type, bool in_record,
 129                                 unsigned int max_align);
 130
 131 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
 132    If TYPE is the best type, return it.  Otherwise, make a new type.  We
 133    only support new integral and pointer types.  FOR_BIASED is true if
 134    we are making a biased type.  */
 135 extern tree make_type_from_size (tree type, tree size_tree, bool for_biased);
 136
 137 /* Ensure that TYPE has SIZE and ALIGN.  Make and return a new padded type
 138    if needed.  We have already verified that SIZE and ALIGN are large enough.
 139    GNAT_ENTITY is used to name the resulting record and to issue a warning.
 140    IS_COMPONENT_TYPE is true if this is being done for the component type of
 141    an array.  DEFINITION is true if this type is being defined.  SET_RM_SIZE
 142    is true if the RM size of the resulting type is to be set to SIZE too; in
 143    this case, the padded type is canonicalized before being returned.  */
 144 extern tree maybe_pad_type (tree type, tree size, unsigned int align,
 145                             Entity_Id gnat_entity, bool is_component_type,
 146                             bool definition, bool set_rm_size);
 147
 148 /* Return true if padded TYPE was built with an RM size.  */
 149 extern bool pad_type_has_rm_size (tree type);
 150
 151 /* Return a copy of the padded TYPE but with reverse storage order.  */
 152 extern tree set_reverse_storage_order_on_pad_type (tree type);
 153
 154 enum alias_set_op
 155 {
 156   ALIAS_SET_COPY,
 157   ALIAS_SET_SUBSET,
 158   ALIAS_SET_SUPERSET
 159 };
 160
 161 /* Relate the alias sets of NEW_TYPE and OLD_TYPE according to OP.
 162    If this is a multi-dimensional array type, do this recursively.
 163
 164    OP may be
 165    - ALIAS_SET_COPY:     the new set is made a copy of the old one.
 166    - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
 167    - ALIAS_SET_SUBSET:   the new set is made a subset of the old one.  */
 168 extern void relate_alias_sets (tree new_type, tree old_type,
 169                                enum alias_set_op op);
 170
 171 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
 172    and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
 173    size and alignment used by Gigi.  Prefer SIZE over TYPE_SIZE if non-null.
 174    BY_REF is true if the object is used by reference.  */
 175 extern void annotate_object (Entity_Id gnat_entity, tree gnu_type, tree size,
 176                              bool by_ref);
 177
 178 /* Return the variant part of RECORD_TYPE, if any.  Otherwise return NULL.  */
 179 extern tree get_variant_part (tree record_type);
 180
 181 /* Given a type T, a FIELD_DECL F, and a replacement value R, return a new
 182    type with all size expressions that contain F updated by replacing F
 183    with R.  If F is NULL_TREE, always make a new RECORD_TYPE, even if
 184    nothing has changed.  */
 185 extern tree substitute_in_type (tree t, tree f, tree r);
 186
 187 /* Return the RM size of GNU_TYPE.  This is the actual number of bits
 188    needed to represent the object.  */
 189 extern tree rm_size (tree gnu_type);
 190
 191 /* Return the name to be used for GNAT_ENTITY.  If a type, create a
 192    fully-qualified name, possibly with type information encoding.
 193    Otherwise, return the name.  */
 194 extern tree get_entity_name (Entity_Id gnat_entity);
 195
 196 /* Return an identifier representing the external name to be used for
 197    GNAT_ENTITY.  If SUFFIX is specified, the name is followed by "___"
 198    and the specified suffix.  */
 199 extern tree create_concat_name (Entity_Id gnat_entity, const char *suffix);
 200
 201 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
 202    string, return a new IDENTIFIER_NODE that is the concatenation of
 203    the name followed by "___" and the specified suffix.  */
 204 extern tree concat_name (tree gnu_name, const char *suffix);
 205
 206 /* Initialize data structures of the decl.cc module.  */
 207 extern void init_gnat_decl (void);
 208
 209 /* Destroy data structures of the decl.cc module.  */
 210 extern void destroy_gnat_decl (void);
 211
 212 /* Highest number in the front-end node table.  */
 213 extern int max_gnat_nodes;
 214
 215 /* True when gigi is being called on an analyzed but unexpanded
 216    tree, and the only purpose of the call is to properly annotate
 217    types with representation information.  */
 218 extern bool type_annotate_only;
 219
 220 /* This structure must be kept synchronized with Call_Back_End.  */
 221 struct File_Info_Type
 222 {
 223   File_Name_Type File_Name;
 224   Instance_Id    Instance;
 225   Nat            Num_Source_Lines;
 226 };
 227
 228 #ifdef __cplusplus
 229 extern "C" {
 230 #endif
 231
 232 /* This is the main program of the back-end.  It sets up all the table
 233    structures and then generates code.  */
 234 extern void gigi (Node_Id gnat_root,
 235                   int max_gnat_node,
 236                   int number_name,
 237                   Node_Header *node_offsets_ptr,
 238                   any_slot *slots_ptr,
 239                   Node_Id *next_node_ptr,
 240                   Node_Id *prev_node_ptr,
 241                   struct Elist_Header *elists_ptr,
 242                   struct Elmt_Item *elmts_ptr,
 243                   struct String_Entry *strings_ptr,
 244                   Char_Code *strings_chars_ptr,
 245                   struct List_Header *list_headers_ptr,
 246                   Nat number_file,
 247                   struct File_Info_Type *file_info_ptr,
 248                   Entity_Id standard_address,
 249                   Entity_Id standard_boolean,
 250                   Entity_Id standard_character,
 251                   Entity_Id standard_exception_type,
 252                   Entity_Id standard_integer,
 253                   Entity_Id standard_long_long_float,
 254                   Int gigi_operating_mode);
 255
 256 #ifdef __cplusplus
 257 }
 258 #endif
 259
 260 /* GNAT_NODE is the root of some GNAT tree.  Return the root of the
 261    GCC tree corresponding to that GNAT tree.  */
 262 extern tree gnat_to_gnu (Node_Id gnat_node);
 263
 264 /* Similar to gnat_to_gnu, but discard any object that might be created in
 265    the course of the translation of GNAT_NODE, which must be an "external"
 266    expression in the sense that it will be elaborated elsewhere.  */
 267 extern tree gnat_to_gnu_external (Node_Id gnat_node);
 268
 269 /* GNU_STMT is a statement.  We generate code for that statement.  */
 270 extern void gnat_expand_stmt (tree gnu_stmt);
 271
 272 /* Generate GIMPLE in place for the expression at *EXPR_P.  */
 273 extern int gnat_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *);
 274
 275 /* Do the processing for the declaration of a GNAT_ENTITY, a type.  If
 276    a separate Freeze node exists, delay the bulk of the processing.  Otherwise
 277    make a GCC type for GNAT_ENTITY and set up the correspondence.  */
 278 extern void process_type (Entity_Id gnat_entity);
 279
 280 /* Convert SLOC into LOCUS.  Return true if SLOC corresponds to a source code
 281    location and false if it doesn't.  If CLEAR_COLUMN is true, set the column
 282    information to 0.  */
 283 extern bool Sloc_to_locus (Source_Ptr Sloc, location_t *locus,
 284                            bool clear_column = false, const_tree decl = 0);
 285
 286 /* Post an error message.  MSG is the error message, properly annotated.
 287    NODE is the node at which to post the error and the node to use for the
 288    '&' substitution.  */
 289 extern void post_error (const char *msg, Node_Id node);
 290
 291 /* Similar to post_error, but NODE is the node at which to post the error and
 292    ENT is the node to use for the '&' substitution.  */
 293 extern void post_error_ne (const char *msg, Node_Id node, Entity_Id ent);
 294
 295 /* Similar to post_error_ne, but NUM is the number to use for the '^'.  */
 296 extern void post_error_ne_num (const char *msg, Node_Id node, Entity_Id ent,
 297                                int num);
 298
 299 /* Similar to post_error_ne, but T is a GCC tree representing the number to
 300    write.  If T represents a constant, the text inside curly brackets in
 301    MSG will be output (presumably including a '^').  Otherwise it will not
 302    be output and the text inside square brackets will be output instead.  */
 303 extern void post_error_ne_tree (const char *msg, Node_Id node, Entity_Id ent,
 304                                 tree t);
 305
 306 /* Similar to post_error_ne_tree, but NUM is a second integer to write.  */
 307 extern void post_error_ne_tree_2 (const char *msg, Node_Id node, Entity_Id ent,
 308                                   tree t, int num);
 309
 310 /* Return a label to branch to for the exception type in KIND or Empty
 311    if none.  */
 312 extern Entity_Id get_exception_label (char kind);
 313
 314 /* If nonzero, pretend we are allocating at global level.  */
 315 extern int force_global;
 316
 317 /* The default alignment of "double" floating-point types, i.e. floating
 318    point types whose size is equal to 64 bits, or 0 if this alignment is
 319    not specifically capped.  */
 320 extern int double_float_alignment;
 321
 322 /* The default alignment of "double" or larger scalar types, i.e. scalar
 323    types whose size is greater or equal to 64 bits, or 0 if this alignment
 324    is not specifically capped.  */
 325 extern int double_scalar_alignment;
 326
 327 /* True if floating-point arithmetics may use wider intermediate results.  */
 328 extern bool fp_arith_may_widen;
 329
 330 /* Data structures used to represent attributes.  */
 331
 332 enum attrib_type
 333 {
 334   ATTR_MACHINE_ATTRIBUTE,
 335   ATTR_LINK_ALIAS,
 336   ATTR_LINK_SECTION,
 337   ATTR_LINK_CONSTRUCTOR,
 338   ATTR_LINK_DESTRUCTOR,
 339   ATTR_THREAD_LOCAL_STORAGE,
 340   ATTR_WEAK_EXTERNAL
 341 };
 342
 343 struct attrib
 344 {
 345   struct attrib *next;
 346   enum attrib_type type;
 347   tree name;
 348   tree args;
 349   Node_Id error_point;
 350 };
 351
 352 /* Table of machine-independent internal attributes.  */
 353 extern const struct scoped_attribute_specs gnat_internal_attribute_table;
 354
 355 /* Define the entries in the standard data array.  */
 356 enum standard_datatypes
 357 {
 358   /* The longest floating-point type.  */
 359   ADT_longest_float_type,
 360
 361   /* The type of an exception.  */
 362   ADT_except_type,
 363
 364   /* Function type declaration -- void T() */
 365   ADT_void_ftype,
 366
 367   /* Type declaration node  <==> typedef void *T() */
 368   ADT_ptr_void_ftype,
 369
 370   /* Type declaration node  <==> typedef virtual void *T() */
 371   ADT_fdesc_type,
 372
 373   /* Null pointer for above type.  */
 374   ADT_null_fdesc,
 375
 376   /* Value 1 in signed bitsizetype.  */
 377   ADT_sbitsize_one_node,
 378
 379   /* Value BITS_PER_UNIT in signed bitsizetype.  */
 380   ADT_sbitsize_unit_node,
 381
 382   /* Function declaration node for run-time allocation function.  */
 383   ADT_malloc_decl,
 384
 385   /* Function declaration node for run-time freeing function.  */
 386   ADT_free_decl,
 387
 388   /* Function declaration node for run-time reallocation function.  */
 389   ADT_realloc_decl,
 390
 391   /* Function decl node for 64-bit multiplication with overflow checking.  */
 392   ADT_mulv64_decl,
 393
 394   /* Function decl node for 128-bit multiplication with overflow checking.  */
 395   ADT_mulv128_decl,
 396
 397   /* Identifier for the name of the _Parent field in tagged record types.  */
 398   ADT_parent_name_id,
 399
 400   /* Identifier for the name of the Not_Handled_By_Others field.  */
 401   ADT_not_handled_by_others_name_id,
 402
 403   /* Types and decls used by the exception mechanism.  */
 404   ADT_reraise_zcx_decl,
 405   ADT_set_exception_parameter_decl,
 406   ADT_begin_handler_decl,
 407   ADT_end_handler_decl,
 408   ADT_unhandled_except_decl,
 409   ADT_others_decl,
 410   ADT_all_others_decl,
 411   ADT_unhandled_others_decl,
 412
 413   ADT_LAST
 414 };
 415
 416 /* Define kind of exception information associated with raise statements.  */
 417 enum exception_info_kind
 418 {
 419   /* Simple exception information: file:line.  */
 420   exception_simple,
 421   /* Range exception information: file:line + index, first, last.  */
 422   exception_range,
 423   /* Column exception information: file:line:column.  */
 424   exception_column
 425 };
 426
 427 /* Define the inline status of a subprogram.  */
 428 enum inline_status_t
 429 {
 430   /* Inlining is suppressed for the subprogram.  */
 431   is_suppressed,
 432   /* No inlining is requested for the subprogram.  */
 433   is_default,
 434   /* Inlining is requested for the subprogram.  */
 435   is_requested,
 436   /* Inlining is strongly requested for the subprogram.  */
 437   is_prescribed,
 438   /* Inlining is required for the subprogram.  */
 439   is_required
 440 };
 441
 442 extern GTY(()) tree gnat_std_decls[(int) ADT_LAST];
 443 extern GTY(()) tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
 444 extern GTY(()) tree gnat_raise_decls_ext[(int) LAST_REASON_CODE + 1];
 445
 446 #define longest_float_type_node gnat_std_decls[(int) ADT_longest_float_type]
 447 #define except_type_node gnat_std_decls[(int) ADT_except_type]
 448 #define void_ftype gnat_std_decls[(int) ADT_void_ftype]
 449 #define ptr_void_ftype gnat_std_decls[(int) ADT_ptr_void_ftype]
 450 #define fdesc_type_node gnat_std_decls[(int) ADT_fdesc_type]
 451 #define null_fdesc_node gnat_std_decls[(int) ADT_null_fdesc]
 452 #define sbitsize_one_node gnat_std_decls[(int) ADT_sbitsize_one_node]
 453 #define sbitsize_unit_node gnat_std_decls[(int) ADT_sbitsize_unit_node]
 454 #define malloc_decl gnat_std_decls[(int) ADT_malloc_decl]
 455 #define free_decl gnat_std_decls[(int) ADT_free_decl]
 456 #define realloc_decl gnat_std_decls[(int) ADT_realloc_decl]
 457 #define mulv64_decl gnat_std_decls[(int) ADT_mulv64_decl]
 458 #define mulv128_decl gnat_std_decls[(int) ADT_mulv128_decl]
 459 #define parent_name_id gnat_std_decls[(int) ADT_parent_name_id]
 460 #define not_handled_by_others_name_id \
 461           gnat_std_decls[(int) ADT_not_handled_by_others_name_id]
 462 #define reraise_zcx_decl gnat_std_decls[(int) ADT_reraise_zcx_decl]
 463 #define set_exception_parameter_decl \
 464           gnat_std_decls[(int) ADT_set_exception_parameter_decl]
 465 #define begin_handler_decl gnat_std_decls[(int) ADT_begin_handler_decl]
 466 #define end_handler_decl gnat_std_decls[(int) ADT_end_handler_decl]
 467 #define unhandled_except_decl gnat_std_decls[(int) ADT_unhandled_except_decl]
 468 #define others_decl gnat_std_decls[(int) ADT_others_decl]
 469 #define all_others_decl gnat_std_decls[(int) ADT_all_others_decl]
 470 #define unhandled_others_decl gnat_std_decls[(int) ADT_unhandled_others_decl]
 471
 472 /* Routines expected by the gcc back-end. They must have exactly the same
 473    prototype and names as below.  */
 474
 475 /* Return true if we are in the global binding level.  */
 476 extern bool global_bindings_p (void);
 477
 478 /* Enter and exit a new binding level.  */
 479 extern void gnat_pushlevel (void);
 480 extern void gnat_poplevel (void);
 481 extern void gnat_zaplevel (void);
 482
 483 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
 484    and point FNDECL to this BLOCK.  */
 485 extern void set_current_block_context (tree fndecl);
 486
 487 /* Record DECL as belonging to the current lexical scope and use GNAT_NODE
 488    for location information and flag propagation.  */
 489 extern void gnat_pushdecl (tree decl, Node_Id gnat_node);
 490
 491 /* Initialize the GCC support for exception handling.  */
 492 extern void gnat_init_gcc_eh (void);
 493
 494 /* Initialize the GCC support for floating-point operations.  */
 495 extern void gnat_init_gcc_fp (void);
 496
 497 /* Install the builtin functions we might need.  */
 498 extern void gnat_install_builtins (void);
 499
 500 /* Return an integer type with the number of bits of precision given by
 501    PRECISION.  UNSIGNEDP is nonzero if the type is unsigned; otherwise
 502    it is a signed type.  */
 503 extern tree gnat_type_for_size (unsigned precision, int unsignedp);
 504
 505 /* Return a data type that has machine mode MODE.  UNSIGNEDP selects
 506    an unsigned type; otherwise a signed type is returned.  */
 507 extern tree gnat_type_for_mode (machine_mode mode, int unsignedp);
 508
 509 /* Perform final processing on global declarations.  */
 510 extern void gnat_write_global_declarations (void);
 511
 512 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
 513    signedness being specified by UNSIGNEDP.  */
 514 extern tree gnat_signed_or_unsigned_type_for (int unsignedp, tree type_node);
 515
 516 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
 517    transparently converted to each other.  */
 518 extern int gnat_types_compatible_p (tree t1, tree t2);
 519
 520 /* Return true if EXPR is a useless type conversion.  */
 521 extern bool gnat_useless_type_conversion (tree expr);
 522
 523 /* Return true if T, a {FUNCTION,METHOD}_TYPE, has the specified flags.  */
 524 extern bool fntype_same_flags_p (const_tree, tree, bool, bool);
 525
 526 /* Create an expression whose value is that of EXPR,
 527    converted to type TYPE.  The TREE_TYPE of the value
 528    is always TYPE.  This function implements all reasonable
 529    conversions; callers should filter out those that are
 530    not permitted by the language being compiled.  */
 531 extern tree convert (tree type, tree expr);
 532
 533 /* Create an expression whose value is that of EXPR converted to the common
 534    index type, which is sizetype.  */
 535 extern tree convert_to_index_type (tree expr);
 536
 537 /* Routines created solely for the tree translator's sake. Their prototypes
 538    can be changed as desired.  */
 539
 540 /* Initialize data structures of the utils.cc module.  */
 541 extern void init_gnat_utils (void);
 542
 543 /* Destroy data structures of the utils.cc module.  */
 544 extern void destroy_gnat_utils (void);
 545
 546 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
 547    GNU_DECL is the GCC tree which is to be associated with
 548    GNAT_ENTITY. Such gnu tree node is always an ..._DECL node.
 549    If NO_CHECK is nonzero, the latter check is suppressed.
 550    If GNU_DECL is zero, a previous association is to be reset.  */
 551 extern void save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl,
 552                            bool no_check);
 553
 554 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
 555    Return the ..._DECL node that was associated with it.  If there is no tree
 556    node associated with GNAT_ENTITY, abort.  */
 557 extern tree get_gnu_tree (Entity_Id gnat_entity);
 558
 559 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY.  */
 560 extern bool present_gnu_tree (Entity_Id gnat_entity);
 561
 562 /* Make a dummy type corresponding to GNAT_TYPE.  */
 563 extern tree make_dummy_type (Entity_Id gnat_type);
 564
 565 /* Return the dummy type that was made for GNAT_TYPE, if any.  */
 566 extern tree get_dummy_type (Entity_Id gnat_type);
 567
 568 /* Build dummy fat and thin pointer types whose designated type is specified
 569    by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter.  */
 570 extern void build_dummy_unc_pointer_types (Entity_Id gnat_desig_type,
 571                                            tree gnu_desig_type);
 572
 573 /* Record TYPE as a builtin type for Ada.  NAME is the name of the type.
 574    ARTIFICIAL_P is true if the type was generated by the compiler.  */
 575 extern void record_builtin_type (const char *name, tree type,
 576                                  bool artificial_p);
 577
 578 /* Finish constructing the character type CHAR_TYPE.  */
 579 extern void finish_character_type (tree char_type);
 580
 581 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
 582    finish constructing the record type as a fat pointer type.  */
 583 extern void finish_fat_pointer_type (tree record_type, tree field_list);
 584
 585 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
 586    finish constructing the record or union type.  If REP_LEVEL is zero, this
 587    record has no representation clause and so will be entirely laid out here.
 588    If REP_LEVEL is one, this record has a representation clause and has been
 589    laid out already; only set the sizes and alignment.  If REP_LEVEL is two,
 590    this record is derived from a parent record and thus inherits its layout;
 591    only make a pass on the fields to finalize them.  DEBUG_INFO_P is true if
 592    additional debug info needs to be output for this type.  */
 593 extern void finish_record_type (tree record_type, tree field_list,
 594                                 int rep_level, bool debug_info_p);
 595
 596 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
 597    associated with it.  It need not be invoked directly in most cases as
 598    finish_record_type takes care of doing so.  */
 599 extern void rest_of_record_type_compilation (tree record_type);
 600
 601 /* Append PARALLEL_TYPE on the chain of parallel types for TYPE.  */
 602 extern void add_parallel_type (tree type, tree parallel_type);
 603
 604 /* Return a copy of TYPE, but safe to modify in any way.  */
 605 extern tree copy_type (tree type);
 606
 607 /* Return a subtype of sizetype with range MIN to MAX and whose
 608    TYPE_INDEX_TYPE is INDEX.  GNAT_NODE is used for the position
 609    of the associated TYPE_DECL.  */
 610 extern tree create_index_type (tree min, tree max, tree index,
 611                                Node_Id gnat_node);
 612
 613 /* Return a subtype of TYPE with range MIN to MAX.  If TYPE is NULL,
 614    sizetype is used.  */
 615 extern tree create_range_type (tree type, tree min, tree max);
 616
 617 /* Return an extra subtype of TYPE with range MIN to MAX.  */
 618 extern tree create_extra_subtype (tree type, tree min, tree max);
 619
 620 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
 621    NAME gives the name of the type to be used in the declaration.  */
 622 extern tree create_type_stub_decl (tree name, tree type);
 623
 624 /* Return a TYPE_DECL node for TYPE.  NAME gives the name of the type to be
 625    used in the declaration.  ARTIFICIAL_P is true if the declaration was
 626    generated by the compiler.  DEBUG_INFO_P is true if we need to write
 627    debug information about this type.  GNAT_NODE is used for the position
 628    of the decl.  */
 629 extern tree create_type_decl (tree name, tree type, bool artificial_p,
 630                               bool debug_info_p, Node_Id gnat_node);
 631
 632 /* Return a VAR_DECL or CONST_DECL node.
 633
 634    NAME gives the name of the variable.  ASM_NAME is its assembler name
 635    (if provided).  TYPE is its data type (a GCC ..._TYPE node).  INIT is
 636    the GCC tree for an optional initial expression; NULL_TREE if none.
 637
 638    CONST_FLAG is true if this variable is constant, in which case we might
 639    return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
 640
 641    PUBLIC_FLAG is true if this is for a reference to a public entity or for a
 642    definition to be made visible outside of the current compilation unit, for
 643    instance variable definitions in a package specification.
 644
 645    EXTERN_FLAG is true when processing an external variable declaration (as
 646    opposed to a definition: no storage is to be allocated for the variable).
 647
 648    STATIC_FLAG is only relevant when not at top level and indicates whether
 649    to always allocate storage to the variable.
 650
 651    VOLATILE_FLAG is true if this variable is declared as volatile.
 652
 653    ARTIFICIAL_P is true if the variable was generated by the compiler.
 654
 655    DEBUG_INFO_P is true if we need to write debug information for it.
 656
 657    ATTR_LIST is the list of attributes to be attached to the variable.
 658
 659    GNAT_NODE is used for the position of the decl.  */
 660 extern tree create_var_decl (tree name, tree asm_name, tree type, tree init,
 661                              bool const_flag, bool public_flag,
 662                              bool extern_flag, bool static_flag,
 663                              bool volatile_flag,
 664                              bool artificial_p, bool debug_info_p,
 665                              struct attrib *attr_list, Node_Id gnat_node,
 666                              bool const_decl_allowed_p = true);
 667
 668 /* Return a FIELD_DECL node.  NAME is the field's name, TYPE is its type and
 669    RECORD_TYPE is the type of the enclosing record.  If SIZE is nonzero, it
 670    is the specified size of the field.  If POS is nonzero, it is the bit
 671    position.  PACKED is 1 if the enclosing record is packed, -1 if it has
 672    Component_Alignment of Storage_Unit.  If ADDRESSABLE is nonzero, it
 673    means we are allowed to take the address of the field; if it is negative,
 674    we should not make a bitfield, which is used by make_aligning_type.  */
 675 extern tree create_field_decl (tree name, tree type, tree record_type,
 676                                tree size, tree pos, int packed,
 677                                int addressable);
 678
 679 /* Return a PARM_DECL node with NAME and TYPE.  */
 680 extern tree create_param_decl (tree name, tree type);
 681
 682 /* Return a LABEL_DECL with NAME.  GNAT_NODE is used for the position of
 683    the decl.  */
 684 extern tree create_label_decl (tree name, Node_Id gnat_node);
 685
 686 /* Return a FUNCTION_DECL node.  NAME is the name of the subprogram, ASM_NAME
 687    its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
 688    the list of its parameters (a list of PARM_DECL nodes chained through the
 689    DECL_CHAIN field).
 690
 691    INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
 692
 693    PUBLIC_FLAG is true if this is for a reference to a public entity or for a
 694    definition to be made visible outside of the current compilation unit.
 695
 696    EXTERN_FLAG is true when processing an external subprogram declaration.
 697
 698    ARTIFICIAL_P is true if the subprogram was generated by the compiler.
 699
 700    DEBUG_INFO_P is true if we need to write debug information for it.
 701
 702    DEFINITION is true if the subprogram is to be considered as a definition.
 703
 704    ATTR_LIST is the list of attributes to be attached to the subprogram.
 705
 706    GNAT_NODE is used for the position of the decl.  */
 707 extern tree create_subprog_decl (tree name, tree asm_name, tree type,
 708                                  tree param_decl_list,
 709                                  enum inline_status_t inline_status,
 710                                  bool public_flag, bool extern_flag,
 711                                  bool artificial_p, bool debug_info_p,
 712                                  bool definition, struct attrib *attr_list,
 713                                  Node_Id gnat_node);
 714
 715 /* Given a subprogram declaration DECL, its assembler name and its type,
 716    finish constructing the subprogram declaration from ASM_NAME and TYPE.  */
 717 extern void finish_subprog_decl (tree decl, tree asm_name, tree type);
 718
 719 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
 720    a TYPE.  If IN_PLACE is true, the tree pointed to by NODE should not be
 721    changed.  GNAT_NODE is used for the position of error messages.  */
 722 extern void process_attributes (tree *node, struct attrib **attr_list,
 723                                 bool in_place, Node_Id gnat_node);
 724
 725 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
 726    body. This routine needs to be invoked before processing the declarations
 727    appearing in the subprogram.  */
 728 extern void begin_subprog_body (tree subprog_decl);
 729
 730 /* Finish translating the current subprogram and set its BODY.  */
 731 extern void end_subprog_body (tree body);
 732
 733 /* Wrap up compilation of SUBPROG_DECL, a subprogram body.  */
 734 extern void rest_of_subprog_body_compilation (tree subprog_decl);
 735
 736 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
 737    EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
 738    Return a constructor for the template.  */
 739 extern tree build_template (tree template_type, tree array_type, tree expr);
 740
 741 /* Build a type to be used to represent an aliased object whose nominal type
 742    is an unconstrained array.  This consists of a RECORD_TYPE containing a
 743    field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
 744    If ARRAY_TYPE is that of an unconstrained array, this is used to represent
 745    an arbitrary unconstrained object.  Use NAME as the name of the record.
 746    DEBUG_INFO_P is true if we need to write debug information for the type.  */
 747 extern tree build_unc_object_type (tree template_type, tree object_type,
 748                                    tree name, bool debug_info_p);
 749
 750 /* Same as build_unc_object_type, but taking a thin or fat pointer type
 751    instead of the template type.  */
 752 extern tree build_unc_object_type_from_ptr (tree thin_fat_ptr_type,
 753                                             tree object_type, tree name,
 754                                             bool debug_info_p);
 755
 756 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.  In
 757    the normal case this is just two adjustments, but we have more to do
 758    if NEW is an UNCONSTRAINED_ARRAY_TYPE.  */
 759 extern void update_pointer_to (tree old_type, tree new_type);
 760
 761 /* EXP is an expression for the size of an object.  If this size contains
 762    discriminant references, replace them with the maximum (if MAX_P) or
 763    minimum (if !MAX_P) possible value of the discriminant.  */
 764 extern tree max_size (tree exp, bool max_p);
 765
 766 /* Try to compute the maximum (if MAX_P) or minimum (if !MAX_P) value for the
 767    expression EXP, for very simple expressions.  Substitute variable references
 768    with their respective type's min/max values.  Return the computed value if
 769    any, or EXP if no value can be computed. */
 770 extern tree max_value (tree exp, bool max_p);
 771
 772 /* Remove all conversions that are done in EXP.  This includes converting
 773    from a padded type or to a left-justified modular type.  If TRUE_ADDRESS
 774    is true, always return the address of the containing object even if
 775    the address is not bit-aligned.  */
 776 extern tree remove_conversions (tree exp, bool true_address);
 777
 778 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
 779    refers to the underlying array.  If its type has TYPE_CONTAINS_TEMPLATE_P,
 780    likewise return an expression pointing to the underlying array.  */
 781 extern tree maybe_unconstrained_array (tree exp);
 782
 783 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
 784    If NOTRUNC_P is true, truncation operations should be suppressed.  */
 785 extern tree unchecked_convert (tree type, tree expr, bool notrunc_p);
 786
 787 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
 788    the latter being a record type as predicated by Is_Record_Type.  */
 789 extern enum tree_code tree_code_for_record_type (Entity_Id gnat_type);
 790
 791 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
 792    size is equal to 64 bits, or an array of such a type.  Set ALIGN_CLAUSE
 793    according to the presence of an alignment clause on the type or, if it
 794    is an array, on the component type.  */
 795 extern bool is_double_float_or_array (Entity_Id gnat_type,
 796                                       bool *align_clause);
 797
 798 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
 799    size is greater or equal to 64 bits, or an array of such a type.  Set
 800    ALIGN_CLAUSE according to the presence of an alignment clause on the
 801    type or, if it is an array, on the component type.  */
 802 extern bool is_double_scalar_or_array (Entity_Id gnat_type,
 803                                        bool *align_clause);
 804
 805 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
 806    component of an aggregate type.  */
 807 extern bool type_for_nonaliased_component_p (tree gnu_type);
 808
 809 /* Return true if TYPE is a smaller form of ORIG_TYPE.  */
 810 extern bool smaller_form_type_p (tree type, tree orig_type);
 811
 812 /* Return the base type of TYPE.  */
 813 extern tree get_base_type (tree type);
 814
 815 /* EXP is a GCC tree representing an address.  See if we can find how
 816    strictly the object at that address is aligned.   Return that alignment
 817    strictly the object at that address is aligned.   Return that alignment
 818    in bits.  If we don't know anything about the alignment, return 0.  */
 819 extern unsigned int known_alignment (tree exp);
 820
 821 /* Return true if TYPE is a type with variable size or a padding type with a
 822    field of variable size or a record that has a field with such a type.  */
 823 extern bool type_has_variable_size (tree type);
 824
 825 /* Return true if VALUE is a multiple of FACTOR. FACTOR must be a power
 826    of 2.  */
 827 extern bool value_factor_p (tree value, unsigned HOST_WIDE_INT factor);
 828
 829 /* Build an atomic load for the underlying atomic object in SRC.  SYNC is
 830    true if the load requires synchronization.  */
 831 extern tree build_atomic_load (tree src, bool sync);
 832
 833 /* Build an atomic store from SRC to the underlying atomic object in DEST.
 834    SYNC is true if the store requires synchronization.  */
 835 extern tree build_atomic_store (tree dest, tree src, bool sync);
 836
 837 /* Build a load-modify-store sequence from SRC to DEST.  GNAT_NODE is used for
 838    the location of the sequence.  Note that, even if the load and the store are
 839    both atomic, the sequence itself is not atomic.  */
 840 extern tree build_load_modify_store (tree dest, tree src, Node_Id gnat_node);
 841
 842 /* Make a binary operation of kind OP_CODE.  RESULT_TYPE is the type
 843    desired for the result.  Usually the operation is to be performed
 844    in that type.  For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
 845    in which case the type to be used will be derived from the operands.
 846    Don't fold the result if NO_FOLD is true.  */
 847 extern tree build_binary_op (enum tree_code op_code, tree result_type,
 848                              tree left_operand, tree right_operand,
 849                              bool no_fold=false);
 850
 851 /* Similar, but make unary operation.  */
 852 extern tree build_unary_op (enum tree_code op_code, tree result_type,
 853                             tree operand);
 854
 855 /* Similar, but for COND_EXPR.  */
 856 extern tree build_cond_expr (tree result_type, tree condition_operand,
 857                              tree true_operand, tree false_operand);
 858
 859 /* Similar, but for COMPOUND_EXPR.  */
 860 extern tree build_compound_expr (tree result_type, tree stmt_operand,
 861                                  tree expr_operand);
 862
 863 /* Conveniently construct a function call expression.  FNDECL names the
 864    function to be called, N is the number of arguments, and the "..."
 865    parameters are the argument expressions.  Unlike build_call_expr
 866    this doesn't fold the call, hence it will always return a CALL_EXPR.  */
 867 extern tree build_call_n_expr (tree fndecl, int n, ...);
 868
 869 /* Build a call to a function that raises an exception and passes file name
 870    and line number, if requested.  MSG says which exception function to call.
 871    GNAT_NODE is the node conveying the source location for which the error
 872    should be signaled, or Empty in which case the error is signaled for the
 873    current location.  KIND says which kind of exception node this is for,
 874    among N_Raise_{Constraint,Storage,Program}_Error.  */
 875 extern tree build_call_raise (int msg, Node_Id gnat_node, char kind);
 876
 877 /* Similar to build_call_raise, with extra information about the column
 878    where the check failed.  */
 879 extern tree build_call_raise_column (int msg, Node_Id gnat_node, char kind);
 880
 881 /* Similar to build_call_raise_column, for an index or range check exception ,
 882    with extra information of the form "INDEX out of range FIRST..LAST".  */
 883 extern tree build_call_raise_range (int msg, Node_Id gnat_node, char kind,
 884                                     tree index, tree first, tree last);
 885
 886 /* Return a CONSTRUCTOR of TYPE whose elements are V.  This is not the
 887    same as build_constructor in the language-independent tree.cc.  */
 888 extern tree gnat_build_constructor (tree type, vec<constructor_elt, va_gc> *v);
 889
 890 /* Return a COMPONENT_REF to access FIELD in RECORD, or NULL_EXPR and generate
 891    a Constraint_Error if the field is not found in the record.  Don't fold the
 892    result if NO_FOLD is true.  */
 893 extern tree build_component_ref (tree record, tree field, bool no_fold);
 894
 895 /* Build a GCC tree to call an allocation or deallocation function.
 896    If GNU_OBJ is nonzero, it is an object to deallocate.  Otherwise,
 897    generate an allocator.
 898
 899    GNU_SIZE is the number of bytes to allocate and GNU_TYPE is the contained
 900    object type, used to determine the to-be-honored address alignment.
 901    GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the storage
 902    pool to use.  If not present, malloc and free are used.  GNAT_NODE is used
 903    to provide an error location for restriction violation messages.  */
 904 extern tree build_call_alloc_dealloc (tree gnu_obj, tree gnu_size,
 905                                       tree gnu_type, Entity_Id gnat_proc,
 906                                       Entity_Id gnat_pool, Node_Id gnat_node);
 907
 908 /* Build a GCC tree to correspond to allocating an object of TYPE whose
 909    initial value if INIT, if INIT is nonzero.  Convert the expression to
 910    RESULT_TYPE, which must be some type of pointer.  Return the tree.
 911
 912    GNAT_PROC and GNAT_POOL optionally give the procedure to call and
 913    the storage pool to use.  GNAT_NODE is used to provide an error
 914    location for restriction violation messages.  If IGNORE_INIT_TYPE is
 915    true, ignore the type of INIT for the purpose of determining the size;
 916    this will cause the maximum size to be allocated if TYPE is of
 917    self-referential size.  */
 918 extern tree build_allocator (tree type, tree init, tree result_type,
 919                              Entity_Id gnat_proc, Entity_Id gnat_pool,
 920                              Node_Id gnat_node, bool);
 921
 922 /* Build a load of SRC using the storage model of GNAT_SMO.  */
 923 extern tree build_storage_model_load (Entity_Id gnat_smo, tree src);
 924
 925 /* Build a load of SRC into DEST using the storage model of GNAT_SMO.
 926    If SIZE is specified, use it, otherwise use the size of SRC.  */
 927 extern tree build_storage_model_load (Entity_Id gnat_smo, tree dest, tree src,
 928                                       tree size = NULL_TREE);
 929
 930 /* Build a store of SRC into DEST using the storage model of GNAT_SMO.
 931    If SIZE is specified, use it, otherwise use the size of DEST.  */
 932 extern tree build_storage_model_store (Entity_Id gnat_smo, tree dest, tree src,
 933                                        tree size = NULL_TREE);
 934
 935 /* Given a tree EXP, instantiate occurrences of LOAD_EXPR in it and associate
 936    them with the storage model of GNAT_SMO.  */
 937 extern tree instantiate_load_in_expr (tree exp, Entity_Id gnat_smo);
 938
 939 /* This macro calls the above function but short-circuits the common
 940    case of a constant to save time and also checks for NULL.  */
 941
 942 #define INSTANTIATE_LOAD_IN_EXPR(EXP, GNAT_SMO) \
 943   ((EXP) == NULL_TREE || TREE_CONSTANT (EXP) ? (EXP)    \
 944    : instantiate_load_in_expr (EXP, GNAT_SMO))
 945
 946 /* Given an array or slice reference, instantiate occurrences of LOAD_EXPR in
 947    it and associate them with the storage model of GNAT_SMO.  */
 948 extern void instantiate_load_in_array_ref (tree ref, Entity_Id gnat_smo);
 949
 950 /* Indicate that we need to take the address of T and that it therefore
 951    should not be allocated in a register.  Returns true if successful.  */
 952 extern bool gnat_mark_addressable (tree t);
 953
 954 /* Save EXP for later use or reuse.  This is equivalent to save_expr in tree.cc
 955    but we know how to handle our own nodes.  */
 956 extern tree gnat_save_expr (tree exp);
 957
 958 /* Protect EXP for immediate reuse.  This is a variant of gnat_save_expr that
 959    is optimized under the assumption that EXP's value doesn't change before
 960    its subsequent reuse(s) except through its potential reevaluation.  */
 961 extern tree gnat_protect_expr (tree exp);
 962
 963 /* This is equivalent to stabilize_reference in tree.cc but we know how to
 964    handle our own nodes and we take extra arguments.  FORCE says whether to
 965    force evaluation of everything in REF.  INIT is set to the first arm of
 966    a COMPOUND_EXPR present in REF, if any.  */
 967 extern tree gnat_stabilize_reference (tree ref, bool force, tree *init);
 968
 969 /* Rewrite reference REF and call FUNC on each expression within REF in the
 970    process.  DATA is passed unmodified to FUNC.  INIT is set to the first
 971    arm of a COMPOUND_EXPR present in REF, if any.  */
 972 typedef tree (*rewrite_fn) (tree, void *);
 973 extern tree gnat_rewrite_reference (tree ref, rewrite_fn func, void *data,
 974                                     tree *init);
 975
 976 /* This is equivalent to get_inner_reference in expr.cc but it returns the
 977    ultimate containing object only if the reference (lvalue) is constant,
 978    i.e. if it doesn't depend on the context in which it is evaluated.  */
 979 extern tree get_inner_constant_reference (tree exp);
 980
 981 /* Return true if EXPR is the addition or the subtraction of a constant and,
 982    if so, set *ADD to the addend, *CST to the constant and *MINUS_P to true
 983    if this is a subtraction.  */
 984 extern bool is_simple_additive_expression (tree expr, tree *add, tree *cst,
 985                                            bool *minus_p);
 986
 987 /* If EXPR is an expression that is invariant in the current function, in the
 988    sense that it can be evaluated anywhere in the function and any number of
 989    times, return EXPR or an equivalent expression.  Otherwise return NULL.  */
 990 extern tree gnat_invariant_expr (tree expr);
 991
 992 /* Implementation of the builtin_function langhook.  */
 993 extern tree gnat_builtin_function (tree decl);
 994
 995 /* Search the chain of currently reachable declarations for a builtin
 996    FUNCTION_DECL node corresponding to function NAME (an IDENTIFIER_NODE).
 997    Return the first node found, if any, or NULL_TREE otherwise.  */
 998 extern tree builtin_decl_for (tree name);
 999
1000 /* GNU_TYPE is a type. Determine if it should be passed by reference by
1001    default.  */
1002 extern bool default_pass_by_ref (tree gnu_type);
1003
1004 /* GNU_TYPE is the type of a subprogram parameter.  Determine from the type
1005    if it should be passed by reference.  */
1006 extern bool must_pass_by_ref (tree gnu_type);
1007
1008 /* Return the size of the FP mode with precision PREC.  */
1009 extern int fp_prec_to_size (int prec);
1010
1011 /* Return the precision of the FP mode with size SIZE.  */
1012 extern int fp_size_to_prec (int size);
1013
1014 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
1015    from the parameter association for the instantiation of a generic.  We do
1016    not want to emit source location for them: the code generated for their
1017    initialization is likely to disturb debugging.  */
1018 extern bool renaming_from_instantiation_p (Node_Id gnat_node);
1019
1020 /* Try to process all nodes in the deferred context queue.  Keep in the queue
1021    the ones that cannot be processed yet, remove the other ones.  If FORCE is
1022    true, force the processing for all nodes, use the global context when nodes
1023    don't have a GNU translation.  */
1024 extern void process_deferred_decl_context (bool force);
1025
1026 /* Return the innermost scope, starting at GNAT_NODE, we are be interested in
1027    the debug info, or Empty if there is no such scope.  If not NULL, set
1028    IS_SUBPROGRAM to whether the returned entity is a subprogram.  */
1029 extern Entity_Id get_debug_scope (Node_Id gnat_node, bool *is_subprogram);
1030
1031 /* Return whether EXPR, which is the renamed object in an object renaming
1032    declaration, can be materialized as a reference (REFERENCE_TYPE).  This
1033    should be synchronized with Exp_Dbug.Debug_Renaming_Declaration.  */
1034 extern bool can_materialize_object_renaming_p (Node_Id expr);
1035
1036 /* Return whether GNAT_ENTITY is a simple constant, i.e. it represents only
1037    its value and reading it has no side effects.  */
1038 extern bool simple_constant_p (Entity_Id gnat_entity);
1039
1040 /* Return the size of TYPE, which must be a positive power of 2.  */
1041 extern unsigned int resolve_atomic_size (tree type);
1042
1043 #ifdef __cplusplus
1044 extern "C" {
1045 #endif
1046
1047 /* These functions return the basic data type sizes and related parameters
1048    about the target machine.  */
1049 extern Pos get_target_bits_per_unit (void);
1050 extern Pos get_target_bits_per_word (void);
1051 extern Pos get_target_char_size (void);
1052 extern Pos get_target_wchar_t_size (void);
1053 extern Pos get_target_short_size (void);
1054 extern Pos get_target_int_size (void);
1055 extern Pos get_target_long_size (void);
1056 extern Pos get_target_long_long_size (void);
1057 extern Pos get_target_long_long_long_size (void);
1058 extern Pos get_target_pointer_size (void);
1059 extern Pos get_target_maximum_default_alignment (void);
1060 extern Pos get_target_system_allocator_alignment (void);
1061 extern Pos get_target_maximum_allowed_alignment (void);
1062 extern Pos get_target_maximum_alignment (void);
1063 extern Nat get_target_float_words_be (void);
1064 extern Nat get_target_words_be (void);
1065 extern Nat get_target_bytes_be (void);
1066 extern Nat get_target_bits_be (void);
1067 extern Nat get_target_strict_alignment (void);
1068 extern Nat get_target_double_float_alignment (void);
1069 extern Nat get_target_double_scalar_alignment (void);
1070
1071 /* This function is called by the front-end to enumerate all the supported
1072    modes for the machine, as well as some predefined C types.  */
1073 extern void enumerate_modes (void (*f) (const char *, int, int, int, int, int,
1074                                         int, int));
1075
1076 #ifdef __cplusplus
1077 }
1078 #endif
1079
1080 /* Use gigi_checking_assert to test invariants in code generation mode.
1081    It's effective only if the compiler is configured with more checking
1082    than the release mode and can be disabled by means of -fchecking.  */
1083 #define gigi_checking_assert(EXPR) \
1084   gcc_checking_assert ((EXPR) || type_annotate_only)
1085
1086 /* Return the smallest power of 2 larger than X.  */
1087
1088 static inline unsigned HOST_WIDE_INT
1089 ceil_pow2 (unsigned HOST_WIDE_INT x)
1090 {
1091   return (unsigned HOST_WIDE_INT) 1 << ceil_log2 (x);
1092 }
1093
1094 /* Return true if EXP, a CALL_EXPR, is an atomic load.  */
1095
1096 static inline bool
1097 call_is_atomic_load (tree exp)
1098 {
1099   tree fndecl = get_callee_fndecl (exp);
1100
1101   if (!(fndecl && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)))
1102     return false;
1103
1104   enum built_in_function code = DECL_FUNCTION_CODE (fndecl);
1105   return BUILT_IN_ATOMIC_LOAD_N <= code && code <= BUILT_IN_ATOMIC_LOAD_16;
1106 }
1107
1108 /* Return true if TYPE is padding a self-referential type.  */
1109
1110 static inline bool
1111 type_is_padding_self_referential (tree type)
1112 {
1113   if (!TYPE_IS_PADDING_P (type))
1114     return false;
1115
1116   return CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type)));
1117 }
1118
1119 /* Return true if a function returning TYPE doesn't return a fixed size.  */
1120
1121 static inline bool
1122 return_type_with_variable_size_p (tree type)
1123 {
1124   if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1125     return true;
1126
1127   /* Return true for an unconstrained type with default discriminant, see
1128      the E_Subprogram_Type case of gnat_to_gnu_entity.  */
1129   if (type_is_padding_self_referential (type))
1130     return true;
1131
1132   return false;
1133 }
1134
1135 /* Return the unsigned version of TYPE_NODE, a scalar type.  */
1136
1137 static inline tree
1138 gnat_unsigned_type_for (tree type_node)
1139 {
1140   return gnat_signed_or_unsigned_type_for (1, type_node);
1141 }
1142
1143 /* Return the signed version of TYPE_NODE, a scalar type.  */
1144
1145 static inline tree
1146 gnat_signed_type_for (tree type_node)
1147 {
1148   return gnat_signed_or_unsigned_type_for (0, type_node);
1149 }
1150
1151 /* Like build_qualified_type, but TYPE_QUALS is added to the existing
1152    qualifiers on TYPE.  */
1153
1154 static inline tree
1155 change_qualified_type (tree type, int type_quals)
1156 {
1157   /* Qualifiers must be put on the associated array type.  */
1158   if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
1159     return type;
1160
1161   return build_qualified_type (type, TYPE_QUALS (type) | type_quals);
1162 }
1163
1164 /* If EXPR's type is a VECTOR_TYPE, return EXPR converted to the associated
1165    TYPE_REPRESENTATIVE_ARRAY.  */
1166
1167 static inline tree
1168 maybe_vector_array (tree expr)
1169 {
1170   tree type = TREE_TYPE (expr);
1171
1172   if (VECTOR_TYPE_P (type))
1173     expr = convert (TYPE_REPRESENTATIVE_ARRAY (type), expr);
1174
1175   return expr;
1176 }
1177
1178 /* Adjust the character type TYPE if need be.  */
1179
1180 static inline tree
1181 maybe_character_type (tree type)
1182 {
1183   if (TREE_CODE (type) == INTEGER_TYPE
1184       && TYPE_STRING_FLAG (type)
1185       && !TYPE_UNSIGNED (type))
1186     type = gnat_unsigned_type_for (type);
1187
1188   return type;
1189 }
1190
1191 /* Adjust the character value EXPR if need be.  */
1192
1193 static inline tree
1194 maybe_character_value (tree expr)
1195 {
1196   tree type = TREE_TYPE (expr);
1197
1198   if (TREE_CODE (type) == INTEGER_TYPE
1199       && TYPE_STRING_FLAG (type)
1200       && !TYPE_UNSIGNED (type))
1201     {
1202       type = gnat_unsigned_type_for (type);
1203       expr = convert (type, expr);
1204     }
1205
1206   return expr;
1207 }
1208
1209 /* Return the debug type of TYPE if it exists, otherwise TYPE itself.  */
1210
1211 static inline tree
1212 maybe_debug_type (tree type)
1213 {
1214   if (TYPE_CAN_HAVE_DEBUG_TYPE_P (type) && TYPE_DEBUG_TYPE (type))
1215     type = TYPE_DEBUG_TYPE (type);
1216
1217   return type;
1218 }
1219
1220 /* Remove the padding around EXPR if need be.  */
1221
1222 static inline tree
1223 maybe_padded_object (tree expr)
1224 {
1225   tree type = TREE_TYPE (expr);
1226
1227   if (TYPE_IS_PADDING_P (type))
1228     expr = convert (TREE_TYPE (TYPE_FIELDS (type)), expr);
1229
1230   return expr;
1231 }
1232
1233 /* Return the type of operand #0 of EXPR.  */
1234
1235 static inline tree
1236 operand_type (tree expr)
1237 {
1238   return TREE_TYPE (TREE_OPERAND (expr, 0));
1239 }
1240
1241 /* Return the second value of a list.  */
1242
1243 static inline tree
1244 list_second (tree list)
1245 {
1246   return TREE_VALUE (TREE_CHAIN (list));
1247 }
1248
1249 /* Return the third value of a list.  */
1250
1251 static inline tree
1252 list_third (tree list)
1253 {
1254   return TREE_VALUE (TREE_CHAIN (TREE_CHAIN (list)));
1255 }