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) 1992-2015, 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 nonzero if this call is intended for a definition.  This is
  38    used for separate compilation where it necessary to know whether an
  39    external declaration or a definition should be created if the GCC equivalent
  40    was not created previously.  The value of 1 is normally used for a nonzero
  41    DEFINITION, but a value of 2 is used in special circumstances, defined in
  42    the code.  */
  43 extern tree gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr,
  44                                 int definition);
  45
  46 /* Similar, but if the returned value is a COMPONENT_REF, return the
  47    FIELD_DECL.  */
  48 extern tree gnat_to_gnu_field_decl (Entity_Id gnat_entity);
  49
  50 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type.  Return
  51    the GCC type corresponding to that entity.  */
  52 extern tree gnat_to_gnu_type (Entity_Id gnat_entity);
  53
  54 /* Start a new statement group chained to the previous group.  */
  55 extern void start_stmt_group (void);
  56
  57 /* Add GNU_STMT to the current statement group.  If it is an expression with
  58    no effects, it is ignored.  */
  59 extern void add_stmt (tree gnu_stmt);
  60
  61 /* Similar, but the statement is always added, regardless of side-effects.  */
  62 extern void add_stmt_force (tree gnu_stmt);
  63
  64 /* Like add_stmt, but set the location of GNU_STMT to that of GNAT_NODE.  */
  65 extern void add_stmt_with_node (tree gnu_stmt, Node_Id gnat_node);
  66
  67 /* Similar, but the statement is always added, regardless of side-effects.  */
  68 extern void add_stmt_with_node_force (tree gnu_stmt, Node_Id gnat_node);
  69
  70 /* Return code corresponding to the current code group.  It is normally
  71    a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if
  72    BLOCK or cleanups were set.  */
  73 extern tree end_stmt_group (void);
  74
  75 /* Set the BLOCK node corresponding to the current code group to GNU_BLOCK.  */
  76 extern void set_block_for_group (tree);
  77
  78 /* Add a declaration statement for GNU_DECL to the current BLOCK_STMT node.
  79    Get SLOC from GNAT_ENTITY.  */
  80 extern void add_decl_expr (tree gnu_decl, Entity_Id gnat_entity);
  81
  82 /* Mark nodes rooted at T with TREE_VISITED and types as having their
  83    sized gimplified.  We use this to indicate all variable sizes and
  84    positions in global types may not be shared by any subprogram.  */
  85 extern void mark_visited (tree t);
  86
  87 /* This macro calls the above function but short-circuits the common
  88    case of a constant to save time and also checks for NULL.  */
  89
  90 #define MARK_VISITED(EXP)               \
  91 do {                                    \
  92   if((EXP) && !CONSTANT_CLASS_P (EXP))  \
  93     mark_visited (EXP);                 \
  94 } while (0)
  95
  96 /* Finalize the processing of From_Limited_With incomplete types.  */
  97 extern void finalize_from_limited_with (void);
  98
  99 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a
 100    kind of type (such E_Task_Type) that has a different type which Gigi
 101    uses for its representation.  If the type does not have a special type
 102    for its representation, return GNAT_ENTITY.  If a type is supposed to
 103    exist, but does not, abort unless annotating types, in which case
 104    return Empty.   If GNAT_ENTITY is Empty, return Empty.  */
 105 extern Entity_Id Gigi_Equivalent_Type (Entity_Id gnat_entity);
 106
 107 /* Given GNAT_ENTITY, elaborate all expressions that are required to
 108    be elaborated at the point of its definition, but do nothing else.  */
 109 extern void elaborate_entity (Entity_Id gnat_entity);
 110
 111 /* Get the unpadded version of a GNAT type.  */
 112 extern tree get_unpadded_type (Entity_Id gnat_entity);
 113
 114 /* Return the DECL associated with the public subprogram GNAT_ENTITY but whose
 115    type has been changed to that of the parameterless procedure, except if an
 116    alias is already present, in which case it is returned instead.  */
 117 extern tree get_minimal_subprog_decl (Entity_Id gnat_entity);
 118
 119 /* Return whether the E_Subprogram_Type/E_Function/E_Procedure GNAT_ENTITY is
 120    a C++ imported method or equivalent.  */
 121 extern bool is_cplusplus_method (Entity_Id gnat_entity);
 122
 123 /* Create a record type that contains a SIZE bytes long field of TYPE with a
 124     starting bit position so that it is aligned to ALIGN bits, and leaving at
 125     least ROOM bytes free before the field.  BASE_ALIGN is the alignment the
 126     record is guaranteed to get.  GNAT_NODE is used for the position of the
 127     associated TYPE_DECL.  */
 128 extern tree make_aligning_type (tree type, unsigned int align, tree size,
 129                                 unsigned int base_align, int room, Node_Id);
 130
 131 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
 132    as the field type of a packed record if IN_RECORD is true, or as the
 133    component type of a packed array if IN_RECORD is false.  See if we can
 134    rewrite it either as a type that has a non-BLKmode, which we can pack
 135    tighter in the packed record case, or as a smaller type.  If so, return
 136    the new type.  If not, return the original type.  */
 137 extern tree make_packable_type (tree type, bool in_record);
 138
 139 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
 140    If TYPE is the best type, return it.  Otherwise, make a new type.  We
 141    only support new integral and pointer types.  FOR_BIASED is true if
 142    we are making a biased type.  */
 143 extern tree make_type_from_size (tree type, tree size_tree, bool for_biased);
 144
 145 /* Ensure that TYPE has SIZE and ALIGN.  Make and return a new padded type
 146    if needed.  We have already verified that SIZE and ALIGN are large enough.
 147    GNAT_ENTITY is used to name the resulting record and to issue a warning.
 148    IS_COMPONENT_TYPE is true if this is being done for the component type of
 149    an array.  IS_USER_TYPE is true if the original type needs to be completed.
 150    DEFINITION is true if this type is being defined.  SET_RM_SIZE is true if
 151    the RM size of the resulting type is to be set to SIZE too.  */
 152 extern tree maybe_pad_type (tree type, tree size, unsigned int align,
 153                             Entity_Id gnat_entity, bool is_component_type,
 154                             bool is_user_type, bool definition,
 155                             bool set_rm_size);
 156
 157 /* Return a copy of the padded TYPE but with reverse storage order.  */
 158 extern tree set_reverse_storage_order_on_pad_type (tree type);
 159
 160 enum alias_set_op
 161 {
 162   ALIAS_SET_COPY,
 163   ALIAS_SET_SUBSET,
 164   ALIAS_SET_SUPERSET
 165 };
 166
 167 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
 168    If this is a multi-dimensional array type, do this recursively.
 169
 170    OP may be
 171    - ALIAS_SET_COPY:     the new set is made a copy of the old one.
 172    - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
 173    - ALIAS_SET_SUBSET:   the new set is made a subset of the old one.  */
 174 extern void relate_alias_sets (tree gnu_new_type, tree gnu_old_type,
 175                                enum alias_set_op op);
 176
 177 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
 178    the value passed against the list of choices.  */
 179 extern tree choices_to_gnu (tree operand, Node_Id choices);
 180
 181 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
 182    and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
 183    size and alignment used by Gigi.  Prefer SIZE over TYPE_SIZE if non-null.
 184    BY_REF is true if the object is used by reference.  */
 185 extern void annotate_object (Entity_Id gnat_entity, tree gnu_type, tree size,
 186                              bool by_ref);
 187
 188 /* Return the variant part of RECORD_TYPE, if any.  Otherwise return NULL.  */
 189 extern tree get_variant_part (tree record_type);
 190
 191 /* Given a type T, a FIELD_DECL F, and a replacement value R, return a new
 192    type with all size expressions that contain F updated by replacing F
 193    with R.  If F is NULL_TREE, always make a new RECORD_TYPE, even if
 194    nothing has changed.  */
 195 extern tree substitute_in_type (tree t, tree f, tree r);
 196
 197 /* Return the RM size of GNU_TYPE.  This is the actual number of bits
 198    needed to represent the object.  */
 199 extern tree rm_size (tree gnu_type);
 200
 201 /* Return the name to be used for GNAT_ENTITY.  If a type, create a
 202    fully-qualified name, possibly with type information encoding.
 203    Otherwise, return the name.  */
 204 extern tree get_entity_name (Entity_Id gnat_entity);
 205
 206 /* Return an identifier representing the external name to be used for
 207    GNAT_ENTITY.  If SUFFIX is specified, the name is followed by "___"
 208    and the specified suffix.  */
 209 extern tree create_concat_name (Entity_Id gnat_entity, const char *suffix);
 210
 211 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
 212    string, return a new IDENTIFIER_NODE that is the concatenation of
 213    the name followed by "___" and the specified suffix.  */
 214 extern tree concat_name (tree gnu_name, const char *suffix);
 215
 216 /* Initialize data structures of the decl.c module.  */
 217 extern void init_gnat_decl (void);
 218
 219 /* Destroy data structures of the decl.c module.  */
 220 extern void destroy_gnat_decl (void);
 221
 222 /* Highest number in the front-end node table.  */
 223 extern int max_gnat_nodes;
 224
 225 /* Current node being treated, in case abort called.  */
 226 extern Node_Id error_gnat_node;
 227
 228 /* True when gigi is being called on an analyzed but unexpanded
 229    tree, and the only purpose of the call is to properly annotate
 230    types with representation information.  */
 231 extern bool type_annotate_only;
 232
 233 /* This structure must be kept synchronized with Call_Back_End.  */
 234 struct File_Info_Type
 235 {
 236   File_Name_Type File_Name;
 237   Instance_Id    Instance;
 238   Nat            Num_Source_Lines;
 239 };
 240
 241 #ifdef __cplusplus
 242 extern "C" {
 243 #endif
 244
 245 /* This is the main program of the back-end.  It sets up all the table
 246    structures and then generates code.  */
 247 extern void gigi (Node_Id gnat_root,
 248                   int max_gnat_node,
 249                   int number_name ATTRIBUTE_UNUSED,
 250                   struct Node *nodes_ptr,
 251                   struct Flags *Flags_Ptr,
 252                   Node_Id *next_node_ptr,
 253                   Node_Id *prev_node_ptr,
 254                   struct Elist_Header *elists_ptr,
 255                   struct Elmt_Item *elmts_ptr,
 256                   struct String_Entry *strings_ptr,
 257                   Char_Code *strings_chars_ptr,
 258                   struct List_Header *list_headers_ptr,
 259                   Nat number_file,
 260                   struct File_Info_Type *file_info_ptr,
 261                   Entity_Id standard_boolean,
 262                   Entity_Id standard_integer,
 263                   Entity_Id standard_character,
 264                   Entity_Id standard_long_long_float,
 265                   Entity_Id standard_exception_type,
 266                   Int gigi_operating_mode);
 267
 268 #ifdef __cplusplus
 269 }
 270 #endif
 271
 272 /* GNAT_NODE is the root of some GNAT tree.  Return the root of the
 273    GCC tree corresponding to that GNAT tree.  Normally, no code is generated;
 274    we just return an equivalent tree which is used elsewhere to generate
 275    code.  */
 276 extern tree gnat_to_gnu (Node_Id gnat_node);
 277
 278 /* GNU_STMT is a statement.  We generate code for that statement.  */
 279 extern void gnat_expand_stmt (tree gnu_stmt);
 280
 281 /* Generate GIMPLE in place for the expression at *EXPR_P.  */
 282 extern int gnat_gimplify_expr (tree *expr_p, gimple_seq *pre_p,
 283                                gimple_seq *post_p ATTRIBUTE_UNUSED);
 284
 285 /* Do the processing for the declaration of a GNAT_ENTITY, a type.  If
 286    a separate Freeze node exists, delay the bulk of the processing.  Otherwise
 287    make a GCC type for GNAT_ENTITY and set up the correspondence.  */
 288 extern void process_type (Entity_Id gnat_entity);
 289
 290 /* Convert SLOC into LOCUS.  Return true if SLOC corresponds to a source code
 291    location and false if it doesn't.  If CLEAR_COLUMN is true, set the column
 292    information to 0.  */
 293 extern bool Sloc_to_locus (Source_Ptr Sloc, location_t *locus,
 294                            bool clear_column = false);
 295
 296 /* Post an error message.  MSG is the error message, properly annotated.
 297    NODE is the node at which to post the error and the node to use for the
 298    '&' substitution.  */
 299 extern void post_error (const char *msg, Node_Id node);
 300
 301 /* Similar to post_error, but NODE is the node at which to post the error and
 302    ENT is the node to use for the '&' substitution.  */
 303 extern void post_error_ne (const char *msg, Node_Id node, Entity_Id ent);
 304
 305 /* Similar to post_error_ne, but NUM is the number to use for the '^'.  */
 306 extern void post_error_ne_num (const char *msg, Node_Id node, Entity_Id ent,
 307                                int num);
 308
 309 /* Similar to post_error_ne, but T is a GCC tree representing the number to
 310    write.  If T represents a constant, the text inside curly brackets in
 311    MSG will be output (presumably including a '^').  Otherwise it will not
 312    be output and the text inside square brackets will be output instead.  */
 313 extern void post_error_ne_tree (const char *msg, Node_Id node, Entity_Id ent,
 314                                 tree t);
 315
 316 /* Similar to post_error_ne_tree, but NUM is a second integer to write.  */
 317 extern void post_error_ne_tree_2 (const char *msg, Node_Id node, Entity_Id ent,
 318                                   tree t, int num);
 319
 320 /* Return a label to branch to for the exception type in KIND or NULL_TREE
 321    if none.  */
 322 extern tree get_exception_label (char kind);
 323
 324 /* Return the decl for the current elaboration procedure.  */
 325 extern tree get_elaboration_procedure (void);
 326
 327 /* If nonzero, pretend we are allocating at global level.  */
 328 extern int force_global;
 329
 330 /* The default alignment of "double" floating-point types, i.e. floating
 331    point types whose size is equal to 64 bits, or 0 if this alignment is
 332    not specifically capped.  */
 333 extern int double_float_alignment;
 334
 335 /* The default alignment of "double" or larger scalar types, i.e. scalar
 336    types whose size is greater or equal to 64 bits, or 0 if this alignment
 337    is not specifically capped.  */
 338 extern int double_scalar_alignment;
 339
 340 /* True if floating-point arithmetics may use wider intermediate results.  */
 341 extern bool fp_arith_may_widen;
 342 \f
 343 /* Data structures used to represent attributes.  */
 344
 345 enum attr_type
 346 {
 347   ATTR_MACHINE_ATTRIBUTE,
 348   ATTR_LINK_ALIAS,
 349   ATTR_LINK_SECTION,
 350   ATTR_LINK_CONSTRUCTOR,
 351   ATTR_LINK_DESTRUCTOR,
 352   ATTR_THREAD_LOCAL_STORAGE,
 353   ATTR_WEAK_EXTERNAL
 354 };
 355
 356 struct attrib
 357 {
 358   struct attrib *next;
 359   enum attr_type type;
 360   tree name;
 361   tree args;
 362   Node_Id error_point;
 363 };
 364
 365 /* Table of machine-independent internal attributes.  */
 366 extern const struct attribute_spec gnat_internal_attribute_table[];
 367
 368 /* Define the entries in the standard data array.  */
 369 enum standard_datatypes
 370 {
 371   /* The longest floating-point type.  */
 372   ADT_longest_float_type,
 373
 374   /* The type of an exception.  */
 375   ADT_except_type,
 376
 377   /* Function type declaration -- void T() */
 378   ADT_void_ftype,
 379
 380   /* Type declaration node  <==> typedef void *T() */
 381   ADT_ptr_void_ftype,
 382
 383   /* Type declaration node  <==> typedef virtual void *T() */
 384   ADT_fdesc_type,
 385
 386   /* Null pointer for above type.  */
 387   ADT_null_fdesc,
 388
 389   /* Value 1 in signed bitsizetype.  */
 390   ADT_sbitsize_one_node,
 391
 392   /* Value BITS_PER_UNIT in signed bitsizetype.  */
 393   ADT_sbitsize_unit_node,
 394
 395   /* Function declaration nodes for run-time functions for allocating memory.
 396      Ada allocators cause calls to this function to be generated.  */
 397   ADT_malloc_decl,
 398
 399   /* Likewise for freeing memory.  */
 400   ADT_free_decl,
 401
 402   /* Function decl node for 64-bit multiplication with overflow checking.  */
 403   ADT_mulv64_decl,
 404
 405   /* Identifier for the name of the _Parent field in tagged record types.  */
 406   ADT_parent_name_id,
 407
 408   /* Identifier for the name of the Exception_Data type.  */
 409   ADT_exception_data_name_id,
 410
 411   /* Types and decls used by the SJLJ exception mechanism.  */
 412   ADT_jmpbuf_type,
 413   ADT_jmpbuf_ptr_type,
 414   ADT_get_jmpbuf_decl,
 415   ADT_set_jmpbuf_decl,
 416   ADT_get_excptr_decl,
 417   ADT_not_handled_by_others_decl,
 418   ADT_setjmp_decl,
 419   ADT_update_setjmp_buf_decl,
 420   ADT_raise_nodefer_decl,
 421
 422   /* Types and decls used by the ZCX exception mechanism.  */
 423   ADT_reraise_zcx_decl,
 424   ADT_set_exception_parameter_decl,
 425   ADT_begin_handler_decl,
 426   ADT_end_handler_decl,
 427   ADT_unhandled_except_decl,
 428   ADT_others_decl,
 429   ADT_all_others_decl,
 430   ADT_unhandled_others_decl,
 431
 432   ADT_LAST};
 433
 434 /* Define kind of exception information associated with raise statements.  */
 435 enum exception_info_kind
 436 {
 437   /* Simple exception information: file:line.  */
 438   exception_simple,
 439   /* Range exception information: file:line + index, first, last.  */
 440   exception_range,
 441   /* Column exception information: file:line:column.  */
 442   exception_column
 443 };
 444
 445 /* Define the inline status of a subprogram.  */
 446 enum inline_status_t
 447 {
 448   /* Inlining is suppressed for the subprogram.  */
 449   is_suppressed,
 450   /* No inlining is requested for the subprogram.  */
 451   is_disabled,
 452   /* Inlining is requested for the subprogram.  */
 453   is_enabled,
 454   /* Inlining is required for the subprogram.  */
 455   is_required
 456 };
 457
 458 extern GTY(()) tree gnat_std_decls[(int) ADT_LAST];
 459 extern GTY(()) tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
 460 extern GTY(()) tree gnat_raise_decls_ext[(int) LAST_REASON_CODE + 1];
 461
 462 #define longest_float_type_node gnat_std_decls[(int) ADT_longest_float_type]
 463 #define except_type_node gnat_std_decls[(int) ADT_except_type]
 464 #define void_ftype gnat_std_decls[(int) ADT_void_ftype]
 465 #define ptr_void_ftype gnat_std_decls[(int) ADT_ptr_void_ftype]
 466 #define fdesc_type_node gnat_std_decls[(int) ADT_fdesc_type]
 467 #define null_fdesc_node gnat_std_decls[(int) ADT_null_fdesc]
 468 #define sbitsize_one_node gnat_std_decls[(int) ADT_sbitsize_one_node]
 469 #define sbitsize_unit_node gnat_std_decls[(int) ADT_sbitsize_unit_node]
 470 #define malloc_decl gnat_std_decls[(int) ADT_malloc_decl]
 471 #define free_decl gnat_std_decls[(int) ADT_free_decl]
 472 #define mulv64_decl gnat_std_decls[(int) ADT_mulv64_decl]
 473 #define parent_name_id gnat_std_decls[(int) ADT_parent_name_id]
 474 #define exception_data_name_id gnat_std_decls[(int) ADT_exception_data_name_id]
 475 #define jmpbuf_type gnat_std_decls[(int) ADT_jmpbuf_type]
 476 #define jmpbuf_ptr_type gnat_std_decls[(int) ADT_jmpbuf_ptr_type]
 477 #define get_jmpbuf_decl gnat_std_decls[(int) ADT_get_jmpbuf_decl]
 478 #define set_jmpbuf_decl gnat_std_decls[(int) ADT_set_jmpbuf_decl]
 479 #define get_excptr_decl gnat_std_decls[(int) ADT_get_excptr_decl]
 480 #define not_handled_by_others_decl \
 481           gnat_std_decls[(int) ADT_not_handled_by_others_decl]
 482 #define setjmp_decl gnat_std_decls[(int) ADT_setjmp_decl]
 483 #define update_setjmp_buf_decl gnat_std_decls[(int) ADT_update_setjmp_buf_decl]
 484 #define raise_nodefer_decl gnat_std_decls[(int) ADT_raise_nodefer_decl]
 485 #define reraise_zcx_decl gnat_std_decls[(int) ADT_reraise_zcx_decl]
 486 #define set_exception_parameter_decl \
 487           gnat_std_decls[(int) ADT_set_exception_parameter_decl]
 488 #define begin_handler_decl gnat_std_decls[(int) ADT_begin_handler_decl]
 489 #define others_decl gnat_std_decls[(int) ADT_others_decl]
 490 #define all_others_decl gnat_std_decls[(int) ADT_all_others_decl]
 491 #define unhandled_others_decl gnat_std_decls[(int) ADT_unhandled_others_decl]
 492 #define end_handler_decl gnat_std_decls[(int) ADT_end_handler_decl]
 493 #define unhandled_except_decl gnat_std_decls[(int) ADT_unhandled_except_decl]
 494
 495 /* Routines expected by the gcc back-end. They must have exactly the same
 496    prototype and names as below.  */
 497
 498 /* Return true if we are in the global binding level.  */
 499 extern bool global_bindings_p (void);
 500
 501 /* Enter and exit a new binding level.  */
 502 extern void gnat_pushlevel (void);
 503 extern void gnat_poplevel (void);
 504 extern void gnat_zaplevel (void);
 505
 506 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
 507    and point FNDECL to this BLOCK.  */
 508 extern void set_current_block_context (tree fndecl);
 509
 510 /* Set the jmpbuf_decl for the current binding level to DECL.  */
 511 extern void set_block_jmpbuf_decl (tree decl);
 512
 513 /* Get the setjmp_decl, if any, for the current binding level.  */
 514 extern tree get_block_jmpbuf_decl (void);
 515
 516 /* Record DECL as belonging to the current lexical scope and use GNAT_NODE
 517    for location information and flag propagation.  */
 518 extern void gnat_pushdecl (tree decl, Node_Id gnat_node);
 519
 520 /* Initialize the GCC support for exception handling.  */
 521 extern void gnat_init_gcc_eh (void);
 522
 523 /* Initialize the GCC support for floating-point operations.  */
 524 extern void gnat_init_gcc_fp (void);
 525
 526 /* Install the builtin functions we might need.  */
 527 extern void gnat_install_builtins (void);
 528
 529 /* Return an integer type with the number of bits of precision given by
 530    PRECISION.  UNSIGNEDP is nonzero if the type is unsigned; otherwise
 531    it is a signed type.  */
 532 extern tree gnat_type_for_size (unsigned precision, int unsignedp);
 533
 534 /* Return a data type that has machine mode MODE.  UNSIGNEDP selects
 535    an unsigned type; otherwise a signed type is returned.  */
 536 extern tree gnat_type_for_mode (machine_mode mode, int unsignedp);
 537
 538 /* Perform final processing on global declarations.  */
 539 extern void gnat_write_global_declarations (void);
 540
 541 /* Return the unsigned version of a TYPE_NODE, a scalar type.  */
 542 extern tree gnat_unsigned_type (tree type_node);
 543
 544 /* Return the signed version of a TYPE_NODE, a scalar type.  */
 545 extern tree gnat_signed_type (tree type_node);
 546
 547 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
 548    transparently converted to each other.  */
 549 extern int gnat_types_compatible_p (tree t1, tree t2);
 550
 551 /* Return true if EXPR is a useless type conversion.  */
 552 extern bool gnat_useless_type_conversion (tree expr);
 553
 554 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags.  */
 555 extern bool fntype_same_flags_p (const_tree, tree, bool, bool, bool);
 556
 557 /* Create an expression whose value is that of EXPR,
 558    converted to type TYPE.  The TREE_TYPE of the value
 559    is always TYPE.  This function implements all reasonable
 560    conversions; callers should filter out those that are
 561    not permitted by the language being compiled.  */
 562 extern tree convert (tree type, tree expr);
 563
 564 /* Create an expression whose value is that of EXPR converted to the common
 565    index type, which is sizetype.  */
 566 extern tree convert_to_index_type (tree expr);
 567
 568 /* Routines created solely for the tree translator's sake. Their prototypes
 569    can be changed as desired.  */
 570
 571 /* Initialize data structures of the utils.c module.  */
 572 extern void init_gnat_utils (void);
 573
 574 /* Destroy data structures of the utils.c module.  */
 575 extern void destroy_gnat_utils (void);
 576
 577 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
 578    GNU_DECL is the GCC tree which is to be associated with
 579    GNAT_ENTITY. Such gnu tree node is always an ..._DECL node.
 580    If NO_CHECK is nonzero, the latter check is suppressed.
 581    If GNU_DECL is zero, a previous association is to be reset.  */
 582 extern void save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl,
 583                            bool no_check);
 584
 585 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
 586    Return the ..._DECL node that was associated with it.  If there is no tree
 587    node associated with GNAT_ENTITY, abort.  */
 588 extern tree get_gnu_tree (Entity_Id gnat_entity);
 589
 590 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY.  */
 591 extern bool present_gnu_tree (Entity_Id gnat_entity);
 592
 593 /* Make a dummy type corresponding to GNAT_TYPE.  */
 594 extern tree make_dummy_type (Entity_Id gnat_type);
 595
 596 /* Return the dummy type that was made for GNAT_TYPE, if any.  */
 597 extern tree get_dummy_type (Entity_Id gnat_type);
 598
 599 /* Build dummy fat and thin pointer types whose designated type is specified
 600    by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter.  */
 601 extern void build_dummy_unc_pointer_types (Entity_Id gnat_desig_type,
 602                                            tree gnu_desig_type);
 603
 604 /* Record TYPE as a builtin type for Ada.  NAME is the name of the type.
 605    ARTIFICIAL_P is true if the type was generated by the compiler.  */
 606 extern void record_builtin_type (const char *name, tree type,
 607                                  bool artificial_p);
 608
 609 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
 610    finish constructing the record type as a fat pointer type.  */
 611 extern void finish_fat_pointer_type (tree record_type, tree field_list);
 612
 613 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
 614    finish constructing the record or union type.  If REP_LEVEL is zero, this
 615    record has no representation clause and so will be entirely laid out here.
 616    If REP_LEVEL is one, this record has a representation clause and has been
 617    laid out already; only set the sizes and alignment.  If REP_LEVEL is two,
 618    this record is derived from a parent record and thus inherits its layout;
 619    only make a pass on the fields to finalize them.  DEBUG_INFO_P is true if
 620    we need to write debug information about this type.  */
 621 extern void finish_record_type (tree record_type, tree field_list,
 622                                 int rep_level, bool debug_info_p);
 623
 624 /* Wrap up compilation of RECORD_TYPE, i.e. output all the debug information
 625    associated with it.  It need not be invoked directly in most cases since
 626    finish_record_type takes care of doing so, but this can be necessary if
 627    a parallel type is to be attached to the record type.  */
 628 extern void rest_of_record_type_compilation (tree record_type);
 629
 630 /* Append PARALLEL_TYPE on the chain of parallel types for TYPE.  */
 631 extern void add_parallel_type (tree type, tree parallel_type);
 632
 633 /* Return a FUNCTION_TYPE node.  RETURN_TYPE is the type returned by the
 634    subprogram.  If it is VOID_TYPE, then we are dealing with a procedure,
 635    otherwise we are dealing with a function.  PARAM_DECL_LIST is a list of
 636    PARM_DECL nodes that are the subprogram parameters.  CICO_LIST is the
 637    copy-in/copy-out list to be stored into the TYPE_CICO_LIST field.
 638    RETURN_UNCONSTRAINED_P is true if the function returns an unconstrained
 639    object.  RETURN_BY_DIRECT_REF_P is true if the function returns by direct
 640    reference.  RETURN_BY_INVISI_REF_P is true if the function returns by
 641    invisible reference.  */
 642 extern tree create_subprog_type (tree return_type, tree param_decl_list,
 643                                  tree cico_list, bool return_unconstrained_p,
 644                                  bool return_by_direct_ref_p,
 645                                  bool return_by_invisi_ref_p);
 646
 647 /* Return a copy of TYPE, but safe to modify in any way.  */
 648 extern tree copy_type (tree type);
 649
 650 /* Return a subtype of sizetype with range MIN to MAX and whose
 651    TYPE_INDEX_TYPE is INDEX.  GNAT_NODE is used for the position
 652    of the associated TYPE_DECL.  */
 653 extern tree create_index_type (tree min, tree max, tree index,
 654                                Node_Id gnat_node);
 655
 656 /* Return a subtype of TYPE with range MIN to MAX.  If TYPE is NULL,
 657    sizetype is used.  */
 658 extern tree create_range_type (tree type, tree min, tree max);
 659
 660 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
 661    NAME gives the name of the type to be used in the declaration.  */
 662 extern tree create_type_stub_decl (tree name, tree type);
 663
 664 /* Return a TYPE_DECL node for TYPE.  NAME gives the name of the type to be
 665    used in the declaration.  ARTIFICIAL_P is true if the declaration was
 666    generated by the compiler.  DEBUG_INFO_P is true if we need to write
 667    debug information about this type.  GNAT_NODE is used for the position
 668    of the decl.  */
 669 extern tree create_type_decl (tree name, tree type, bool artificial_p,
 670                               bool debug_info_p, Node_Id gnat_node);
 671
 672 /* Return a VAR_DECL or CONST_DECL node.
 673
 674    NAME gives the name of the variable.  ASM_NAME is its assembler name
 675    (if provided).  TYPE is its data type (a GCC ..._TYPE node).  INIT is
 676    the GCC tree for an optional initial expression; NULL_TREE if none.
 677
 678    CONST_FLAG is true if this variable is constant, in which case we might
 679    return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
 680
 681    PUBLIC_FLAG is true if this definition is to be made visible outside of
 682    the current compilation unit. This flag should be set when processing the
 683    variable definitions in a package specification.
 684
 685    EXTERN_FLAG is nonzero when processing an external variable declaration (as
 686    opposed to a definition: no storage is to be allocated for the variable).
 687
 688    STATIC_FLAG is only relevant when not at top level and indicates whether
 689    to always allocate storage to the variable.
 690
 691    VOLATILE_FLAG is true if this variable is declared as volatile.
 692
 693    ARTIFICIAL_P is true if the variable was generated by the compiler.
 694
 695    DEBUG_INFO_P is true if we need to write debug information for it.
 696
 697    GNAT_NODE is used for the position of the decl.  */
 698 extern tree create_var_decl (tree name, tree asm_name, tree type, tree init,
 699                              bool const_flag, bool public_flag,
 700                              bool extern_flag, bool static_flag,
 701                              bool volatile_flag,
 702                              bool artificial_p, bool debug_info_p,
 703                              struct attrib *attr_list, Node_Id gnat_node,
 704                              bool const_decl_allowed_p = true);
 705
 706 /* Return a FIELD_DECL node.  NAME is the field's name, TYPE is its type and
 707    RECORD_TYPE is the type of the enclosing record.  If SIZE is nonzero, it
 708    is the specified size of the field.  If POS is nonzero, it is the bit
 709    position.  PACKED is 1 if the enclosing record is packed, -1 if it has
 710    Component_Alignment of Storage_Unit.  If ADDRESSABLE is nonzero, it
 711    means we are allowed to take the address of the field; if it is negative,
 712    we should not make a bitfield, which is used by make_aligning_type.  */
 713 extern tree create_field_decl (tree name, tree type, tree record_type,
 714                                tree size, tree pos, int packed,
 715                                int addressable);
 716
 717 /* Return a PARM_DECL node.  NAME is the name of the parameter and TYPE is
 718    its type.  READONLY is true if the parameter is readonly (either an In
 719    parameter or an address of a pass-by-ref parameter).  */
 720 extern tree create_param_decl (tree name, tree type, bool readonly);
 721
 722 /* Return a LABEL_DECL with NAME.  GNAT_NODE is used for the position of
 723    the decl.  */
 724 extern tree create_label_decl (tree name, Node_Id gnat_node);
 725
 726 /* Return a FUNCTION_DECL node.  NAME is the name of the subprogram, ASM_NAME
 727    its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
 728    the list of its parameters (a list of PARM_DECL nodes chained through the
 729    DECL_CHAIN field).
 730
 731    INLINE_STATUS, CONST_FLAG, PUBLIC_FLAG, EXTERN_FLAG, VOLATILE_FLAG as well
 732    as ATTR_LIST are used to set the appropriate fields in the FUNCTION_DECL.
 733
 734    ARTIFICIAL_P is true if the subprogram was generated by the compiler.
 735
 736    DEBUG_INFO_P is true if we need to write debug information for it.
 737
 738    GNAT_NODE is used for the position of the decl.  */
 739 extern tree create_subprog_decl (tree name, tree asm_name, tree type,
 740                                  tree param_decl_list,
 741                                  enum inline_status_t inline_status,
 742                                  bool const_flag, bool public_flag,
 743                                  bool extern_flag, bool volatile_flag,
 744                                  bool artificial_p, bool debug_info_p,
 745                                  struct attrib *attr_list, Node_Id gnat_node);
 746
 747 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
 748    a TYPE.  If IN_PLACE is true, the tree pointed to by NODE should not be
 749    changed.  GNAT_NODE is used for the position of error messages.  */
 750 extern void process_attributes (tree *node, struct attrib **attr_list,
 751                                 bool in_place, Node_Id gnat_node);
 752
 753 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
 754    body. This routine needs to be invoked before processing the declarations
 755    appearing in the subprogram.  */
 756 extern void begin_subprog_body (tree subprog_decl);
 757
 758 /* Finish translating the current subprogram and set its BODY.  */
 759 extern void end_subprog_body (tree body);
 760
 761 /* Wrap up compilation of SUBPROG_DECL, a subprogram body.  */
 762 extern void rest_of_subprog_body_compilation (tree subprog_decl);
 763
 764 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
 765    EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
 766    Return a constructor for the template.  */
 767 extern tree build_template (tree template_type, tree array_type, tree expr);
 768
 769 /* Build a type to be used to represent an aliased object whose nominal type
 770    is an unconstrained array.  This consists of a RECORD_TYPE containing a
 771    field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
 772    If ARRAY_TYPE is that of an unconstrained array, this is used to represent
 773    an arbitrary unconstrained object.  Use NAME as the name of the record.
 774    DEBUG_INFO_P is true if we need to write debug information for the type.  */
 775 extern tree build_unc_object_type (tree template_type, tree object_type,
 776                                    tree name, bool debug_info_p);
 777
 778 /* Same as build_unc_object_type, but taking a thin or fat pointer type
 779    instead of the template type.  */
 780 extern tree build_unc_object_type_from_ptr (tree thin_fat_ptr_type,
 781                                             tree object_type, tree name,
 782                                             bool debug_info_p);
 783
 784 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.  In
 785    the normal case this is just two adjustments, but we have more to do
 786    if NEW is an UNCONSTRAINED_ARRAY_TYPE.  */
 787 extern void update_pointer_to (tree old_type, tree new_type);
 788
 789 /* EXP is an expression for the size of an object.  If this size contains
 790    discriminant references, replace them with the maximum (if MAX_P) or
 791    minimum (if !MAX_P) possible value of the discriminant.  */
 792 extern tree max_size (tree exp, bool max_p);
 793
 794 /* Remove all conversions that are done in EXP.  This includes converting
 795    from a padded type or to a left-justified modular type.  If TRUE_ADDRESS
 796    is true, always return the address of the containing object even if
 797    the address is not bit-aligned.  */
 798 extern tree remove_conversions (tree exp, bool true_address);
 799
 800 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
 801    refers to the underlying array.  If its type has TYPE_CONTAINS_TEMPLATE_P,
 802    likewise return an expression pointing to the underlying array.  */
 803 extern tree maybe_unconstrained_array (tree exp);
 804
 805 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
 806    If NOTRUNC_P is true, truncation operations should be suppressed.  */
 807 extern tree unchecked_convert (tree type, tree expr, bool notrunc_p);
 808
 809 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
 810    the latter being a record type as predicated by Is_Record_Type.  */
 811 extern enum tree_code tree_code_for_record_type (Entity_Id gnat_type);
 812
 813 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
 814    size is equal to 64 bits, or an array of such a type.  Set ALIGN_CLAUSE
 815    according to the presence of an alignment clause on the type or, if it
 816    is an array, on the component type.  */
 817 extern bool is_double_float_or_array (Entity_Id gnat_type,
 818                                       bool *align_clause);
 819
 820 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
 821    size is greater or equal to 64 bits, or an array of such a type.  Set
 822    ALIGN_CLAUSE according to the presence of an alignment clause on the
 823    type or, if it is an array, on the component type.  */
 824 extern bool is_double_scalar_or_array (Entity_Id gnat_type,
 825                                        bool *align_clause);
 826
 827 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
 828    component of an aggregate type.  */
 829 extern bool type_for_nonaliased_component_p (tree gnu_type);
 830
 831 /* Return true if TYPE is a smaller form of ORIG_TYPE.  */
 832 extern bool smaller_form_type_p (tree type, tree orig_type);
 833
 834 /* Return the base type of TYPE.  */
 835 extern tree get_base_type (tree type);
 836
 837 /* EXP is a GCC tree representing an address.  See if we can find how
 838    strictly the object at that address is aligned.   Return that alignment
 839    strictly the object at that address is aligned.   Return that alignment
 840    in bits.  If we don't know anything about the alignment, return 0.  */
 841 extern unsigned int known_alignment (tree exp);
 842
 843 /* Return true if VALUE is a multiple of FACTOR. FACTOR must be a power
 844    of 2.  */
 845 extern bool value_factor_p (tree value, HOST_WIDE_INT factor);
 846
 847 /* Build an atomic load for the underlying atomic object in SRC.  SYNC is
 848    true if the load requires synchronization.  */
 849 extern tree build_atomic_load (tree src, bool sync);
 850
 851 /* Build an atomic store from SRC to the underlying atomic object in DEST.
 852    SYNC is true if the store requires synchronization.  */
 853 extern tree build_atomic_store (tree dest, tree src, bool sync);
 854
 855 /* Build a load-modify-store sequence from SRC to DEST.  GNAT_NODE is used for
 856    the location of the sequence.  Note that, even if the load and the store are
 857    both atomic, the sequence itself is not atomic.  */
 858 extern tree build_load_modify_store (tree dest, tree src, Node_Id gnat_node);
 859
 860 /* Make a binary operation of kind OP_CODE.  RESULT_TYPE is the type
 861    desired for the result.  Usually the operation is to be performed
 862    in that type.  For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
 863    in which case the type to be used will be derived from the operands.  */
 864 extern tree build_binary_op (enum tree_code op_code, tree result_type,
 865                              tree left_operand, tree right_operand);
 866
 867 /* Similar, but make unary operation.  */
 868 extern tree build_unary_op (enum tree_code op_code, tree result_type,
 869                             tree operand);
 870
 871 /* Similar, but for COND_EXPR.  */
 872 extern tree build_cond_expr (tree result_type, tree condition_operand,
 873                              tree true_operand, tree false_operand);
 874
 875 /* Similar, but for COMPOUND_EXPR.  */
 876 extern tree build_compound_expr (tree result_type, tree stmt_operand,
 877                                  tree expr_operand);
 878
 879 /* Conveniently construct a function call expression.  FNDECL names the
 880    function to be called, N is the number of arguments, and the "..."
 881    parameters are the argument expressions.  Unlike build_call_expr
 882    this doesn't fold the call, hence it will always return a CALL_EXPR.  */
 883 extern tree build_call_n_expr (tree fndecl, int n, ...);
 884
 885 /* Build a call to a function that raises an exception and passes file name
 886    and line number, if requested.  MSG says which exception function to call.
 887    GNAT_NODE is the node conveying the source location for which the error
 888    should be signaled, or Empty in which case the error is signaled for the
 889    current location.  KIND says which kind of exception node this is for,
 890    among N_Raise_{Constraint,Storage,Program}_Error.  */
 891 extern tree build_call_raise (int msg, Node_Id gnat_node, char kind);
 892
 893 /* Similar to build_call_raise, with extra information about the column
 894    where the check failed.  */
 895 extern tree build_call_raise_column (int msg, Node_Id gnat_node);
 896
 897 /* Similar to build_call_raise_column, for an index or range check exception ,
 898    with extra information of the form "INDEX out of range FIRST..LAST".  */
 899 extern tree build_call_raise_range (int msg, Node_Id gnat_node,
 900                                     tree index, tree first, tree last);
 901
 902 /* Return a CONSTRUCTOR of TYPE whose elements are V.  This is not the
 903    same as build_constructor in the language-independent tree.c.  */
 904 extern tree gnat_build_constructor (tree type, vec<constructor_elt, va_gc> *v);
 905
 906 /* Return a COMPONENT_REF to access FIELD in RECORD, or NULL_EXPR and generate
 907    a Constraint_Error if the field is not found in the record.  Don't fold the
 908    result if NO_FOLD is true.  */
 909 extern tree build_component_ref (tree record, tree field, bool no_fold);
 910
 911 /* Build a GCC tree to call an allocation or deallocation function.
 912    If GNU_OBJ is nonzero, it is an object to deallocate.  Otherwise,
 913    generate an allocator.
 914
 915    GNU_SIZE is the number of bytes to allocate and GNU_TYPE is the contained
 916    object type, used to determine the to-be-honored address alignment.
 917    GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the storage
 918    pool to use.  If not present, malloc and free are used.  GNAT_NODE is used
 919    to provide an error location for restriction violation messages.  */
 920 extern tree build_call_alloc_dealloc (tree gnu_obj, tree gnu_size,
 921                                       tree gnu_type, Entity_Id gnat_proc,
 922                                       Entity_Id gnat_pool, Node_Id gnat_node);
 923
 924 /* Build a GCC tree to correspond to allocating an object of TYPE whose
 925    initial value if INIT, if INIT is nonzero.  Convert the expression to
 926    RESULT_TYPE, which must be some type of pointer.  Return the tree.
 927
 928    GNAT_PROC and GNAT_POOL optionally give the procedure to call and
 929    the storage pool to use.  GNAT_NODE is used to provide an error
 930    location for restriction violation messages.  If IGNORE_INIT_TYPE is
 931    true, ignore the type of INIT for the purpose of determining the size;
 932    this will cause the maximum size to be allocated if TYPE is of
 933    self-referential size.  */
 934 extern tree build_allocator (tree type, tree init, tree result_type,
 935                              Entity_Id gnat_proc, Entity_Id gnat_pool,
 936                              Node_Id gnat_node, bool);
 937
 938 /* Indicate that we need to take the address of T and that it therefore
 939    should not be allocated in a register.  Returns true if successful.  */
 940 extern bool gnat_mark_addressable (tree t);
 941
 942 /* Save EXP for later use or reuse.  This is equivalent to save_expr in tree.c
 943    but we know how to handle our own nodes.  */
 944 extern tree gnat_save_expr (tree exp);
 945
 946 /* Protect EXP for immediate reuse.  This is a variant of gnat_save_expr that
 947    is optimized under the assumption that EXP's value doesn't change before
 948    its subsequent reuse(s) except through its potential reevaluation.  */
 949 extern tree gnat_protect_expr (tree exp);
 950
 951 /* This is equivalent to stabilize_reference in tree.c but we know how to
 952    handle our own nodes and we take extra arguments.  FORCE says whether to
 953    force evaluation of everything in REF.  INIT is set to the first arm of
 954    a COMPOUND_EXPR present in REF, if any.  */
 955 extern tree gnat_stabilize_reference (tree ref, bool force, tree *init);
 956
 957 /* Rewrite reference REF and call FUNC on each expression within REF in the
 958    process.  DATA is passed unmodified to FUNC.  INIT is set to the first
 959    arm of a COMPOUND_EXPR present in REF, if any.  */
 960 typedef tree (*rewrite_fn) (tree, void *);
 961 extern tree gnat_rewrite_reference (tree ref, rewrite_fn func, void *data,
 962                                     tree *init);
 963
 964 /* This is equivalent to get_inner_reference in expr.c but it returns the
 965    ultimate containing object only if the reference (lvalue) is constant,
 966    i.e. if it doesn't depend on the context in which it is evaluated.  */
 967 extern tree get_inner_constant_reference (tree exp);
 968
 969 /* Return true if EXPR is the addition or the subtraction of a constant and,
 970    if so, set *ADD to the addend, *CST to the constant and *MINUS_P to true
 971    if this is a subtraction.  */
 972 extern bool is_simple_additive_expression (tree expr, tree *add, tree *cst,
 973                                            bool *minus_p);
 974
 975 /* If EXPR is an expression that is invariant in the current function, in the
 976    sense that it can be evaluated anywhere in the function and any number of
 977    times, return EXPR or an equivalent expression.  Otherwise return NULL.  */
 978 extern tree gnat_invariant_expr (tree expr);
 979
 980 /* Implementation of the builtin_function langhook.  */
 981 extern tree gnat_builtin_function (tree decl);
 982
 983 /* Search the chain of currently reachable declarations for a builtin
 984    FUNCTION_DECL node corresponding to function NAME (an IDENTIFIER_NODE).
 985    Return the first node found, if any, or NULL_TREE otherwise.  */
 986 extern tree builtin_decl_for (tree name);
 987
 988 /* GNU_TYPE is a type. Determine if it should be passed by reference by
 989    default.  */
 990 extern bool default_pass_by_ref (tree gnu_type);
 991
 992 /* GNU_TYPE is the type of a subprogram parameter.  Determine from the type
 993    if it should be passed by reference.  */
 994 extern bool must_pass_by_ref (tree gnu_type);
 995
 996 /* Return the size of the FP mode with precision PREC.  */
 997 extern int fp_prec_to_size (int prec);
 998
 999 /* Return the precision of the FP mode with size SIZE.  */
1000 extern int fp_size_to_prec (int size);
1001
1002 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
1003    from the parameter association for the instantiation of a generic.  We do
1004    not want to emit source location for them: the code generated for their
1005    initialization is likely to disturb debugging.  */
1006 extern bool renaming_from_generic_instantiation_p (Node_Id gnat_node);
1007
1008 /* Try to process all nodes in the deferred context queue.  Keep in the queue
1009    the ones that cannot be processed yet, remove the other ones.  If FORCE is
1010    true, force the processing for all nodes, use the global context when nodes
1011    don't have a GNU translation.  */
1012 extern void process_deferred_decl_context (bool force);
1013
1014 /* Return the innermost scope, starting at GNAT_NODE, we are be interested in
1015    the debug info, or Empty if there is no such scope.  If not NULL, set
1016    IS_SUBPROGRAM to whether the returned entity is a subprogram.  */
1017 extern Entity_Id get_debug_scope (Node_Id gnat_node, bool *is_subprogram);
1018
1019 #ifdef __cplusplus
1020 extern "C" {
1021 #endif
1022
1023 /* These functions return the basic data type sizes and related parameters
1024    about the target machine.  */
1025 extern Pos get_target_bits_per_unit (void);
1026 extern Pos get_target_bits_per_word (void);
1027 extern Pos get_target_char_size (void);
1028 extern Pos get_target_wchar_t_size (void);
1029 extern Pos get_target_short_size (void);
1030 extern Pos get_target_int_size (void);
1031 extern Pos get_target_long_size (void);
1032 extern Pos get_target_long_long_size (void);
1033 extern Pos get_target_pointer_size (void);
1034 extern Pos get_target_maximum_default_alignment (void);
1035 extern Pos get_target_system_allocator_alignment (void);
1036 extern Pos get_target_maximum_allowed_alignment (void);
1037 extern Pos get_target_maximum_alignment (void);
1038 extern Nat get_target_float_words_be (void);
1039 extern Nat get_target_words_be (void);
1040 extern Nat get_target_bytes_be (void);
1041 extern Nat get_target_bits_be (void);
1042 extern Nat get_target_strict_alignment (void);
1043 extern Nat get_target_double_float_alignment (void);
1044 extern Nat get_target_double_scalar_alignment (void);
1045
1046 /* This function is called by the front-end to enumerate all the supported
1047    modes for the machine, as well as some predefined C types.  */
1048 extern void enumerate_modes (void (*f) (const char *, int, int, int, int, int,
1049                                         int, int));
1050
1051 #ifdef __cplusplus
1052 }
1053 #endif
1054
1055 /* If EXP's type is a VECTOR_TYPE, return EXP converted to the associated
1056    TYPE_REPRESENTATIVE_ARRAY.  */
1057
1058 static inline tree
1059 maybe_vector_array (tree exp)
1060 {
1061   tree etype = TREE_TYPE (exp);
1062
1063   if (VECTOR_TYPE_P (etype))
1064     exp = convert (TYPE_REPRESENTATIVE_ARRAY (etype), exp);
1065
1066   return exp;
1067 }
1068
1069 /* Return the smallest power of 2 larger than X.  */
1070
1071 static inline unsigned HOST_WIDE_INT
1072 ceil_pow2 (unsigned HOST_WIDE_INT x)
1073 {
1074   return (unsigned HOST_WIDE_INT) 1 << (floor_log2 (x - 1) + 1);
1075 }
1076
1077 /* Return true if EXP, a CALL_EXPR, is an atomic load.  */
1078
1079 static inline bool
1080 call_is_atomic_load (tree exp)
1081 {
1082   tree fndecl = get_callee_fndecl (exp);
1083
1084   if (!(fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL))
1085     return false;
1086
1087   enum built_in_function code = DECL_FUNCTION_CODE (fndecl);
1088   return BUILT_IN_ATOMIC_LOAD_N <= code && code <= BUILT_IN_ATOMIC_LOAD_16;
1089 }
1090
1091 /* Return true if TYPE is padding a self-referential type.  */
1092
1093 static inline bool
1094 type_is_padding_self_referential (tree type)
1095 {
1096   if (!TYPE_IS_PADDING_P (type))
1097     return false;
1098
1099   return CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type)));
1100 }
1101
1102 /* Return true if a function returning TYPE doesn't return a fixed size.  */
1103
1104 static inline bool
1105 return_type_with_variable_size_p (tree type)
1106 {
1107   if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1108     return true;
1109
1110   /* Return true for an unconstrained type with default discriminant, see
1111      the E_Subprogram_Type case of gnat_to_gnu_entity.  */
1112   if (type_is_padding_self_referential (type))
1113     return true;
1114
1115   return false;
1116 }