main/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) 1992-2013, 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_With_Type incomplete types.  */
  97 extern void finalize_from_with_types (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.  */
 127 extern tree make_aligning_type (tree type, unsigned int align, tree size,
 128                                 unsigned int base_align, int room);
 129
 130 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
 131    as the field type of a packed record if IN_RECORD is true, or as the
 132    component type of a packed array if IN_RECORD is false.  See if we can
 133    rewrite it either as a type that has a non-BLKmode, which we can pack
 134    tighter in the packed record case, or as a smaller type.  If so, return
 135    the new type.  If not, return the original type.  */
 136 extern tree make_packable_type (tree type, bool in_record);
 137
 138 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
 139    If TYPE is the best type, return it.  Otherwise, make a new type.  We
 140    only support new integral and pointer types.  FOR_BIASED is true if
 141    we are making a biased type.  */
 142 extern tree make_type_from_size (tree type, tree size_tree, bool for_biased);
 143
 144 /* Ensure that TYPE has SIZE and ALIGN.  Make and return a new padded type
 145    if needed.  We have already verified that SIZE and TYPE are large enough.
 146    GNAT_ENTITY is used to name the resulting record and to issue a warning.
 147    IS_COMPONENT_TYPE is true if this is being done for the component type of
 148    an array.  IS_USER_TYPE is true if the original type needs to be completed.
 149    DEFINITION is true if this type is being defined.  SET_RM_SIZE is true if
 150    the RM size of the resulting type is to be set to SIZE too.  */
 151 extern tree maybe_pad_type (tree type, tree size, unsigned int align,
 152                             Entity_Id gnat_entity, bool is_component_type,
 153                             bool is_user_type, bool definition,
 154                             bool set_rm_size);
 155
 156 enum alias_set_op
 157 {
 158   ALIAS_SET_COPY,
 159   ALIAS_SET_SUBSET,
 160   ALIAS_SET_SUPERSET
 161 };
 162
 163 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
 164    If this is a multi-dimensional array type, do this recursively.
 165
 166    OP may be
 167    - ALIAS_SET_COPY:     the new set is made a copy of the old one.
 168    - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
 169    - ALIAS_SET_SUBSET:   the new set is made a subset of the old one.  */
 170 extern void relate_alias_sets (tree gnu_new_type, tree gnu_old_type,
 171                                enum alias_set_op op);
 172
 173 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
 174    the value passed against the list of choices.  */
 175 extern tree choices_to_gnu (tree operand, Node_Id choices);
 176
 177 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
 178    and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
 179    size and alignment used by Gigi.  Prefer SIZE over TYPE_SIZE if non-null.
 180    BY_REF is true if the object is used by reference and BY_DOUBLE_REF is
 181    true if the object is used by double reference.  */
 182 extern void annotate_object (Entity_Id gnat_entity, tree gnu_type, tree size,
 183                              bool by_ref, bool by_double_ref);
 184
 185 /* Return the variant part of RECORD_TYPE, if any.  Otherwise return NULL.  */
 186 extern tree get_variant_part (tree record_type);
 187
 188 /* Given a type T, a FIELD_DECL F, and a replacement value R, return a new
 189    type with all size expressions that contain F updated by replacing F
 190    with R.  If F is NULL_TREE, always make a new RECORD_TYPE, even if
 191    nothing has changed.  */
 192 extern tree substitute_in_type (tree t, tree f, tree r);
 193
 194 /* Return the RM size of GNU_TYPE.  This is the actual number of bits
 195    needed to represent the object.  */
 196 extern tree rm_size (tree gnu_type);
 197
 198 /* Return the name to be used for GNAT_ENTITY.  If a type, create a
 199    fully-qualified name, possibly with type information encoding.
 200    Otherwise, return the name.  */
 201 extern tree get_entity_name (Entity_Id gnat_entity);
 202
 203 /* Return an identifier representing the external name to be used for
 204    GNAT_ENTITY.  If SUFFIX is specified, the name is followed by "___"
 205    and the specified suffix.  */
 206 extern tree create_concat_name (Entity_Id gnat_entity, const char *suffix);
 207
 208 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
 209    string, return a new IDENTIFIER_NODE that is the concatenation of
 210    the name followed by "___" and the specified suffix.  */
 211 extern tree concat_name (tree gnu_name, const char *suffix);
 212
 213 /* Highest number in the front-end node table.  */
 214 extern int max_gnat_nodes;
 215
 216 /* Current node being treated, in case abort called.  */
 217 extern Node_Id error_gnat_node;
 218
 219 /* True when gigi is being called on an analyzed but unexpanded
 220    tree, and the only purpose of the call is to properly annotate
 221    types with representation information.  */
 222 extern bool type_annotate_only;
 223
 224 /* Current file name without path.  */
 225 extern const char *ref_filename;
 226
 227 /* This structure must be kept synchronized with Call_Back_End.  */
 228 struct File_Info_Type
 229 {
 230   File_Name_Type File_Name;
 231   Instance_Id    Instance;
 232   Nat            Num_Source_Lines;
 233 };
 234
 235 #ifdef __cplusplus
 236 extern "C" {
 237 #endif
 238
 239 /* This is the main program of the back-end.  It sets up all the table
 240    structures and then generates code.  */
 241 extern void gigi (Node_Id gnat_root, int max_gnat_node,
 242                   int number_name ATTRIBUTE_UNUSED,
 243                   struct Node *nodes_ptr, Node_Id *next_node_ptr,
 244                   Node_Id *prev_node_ptr, struct Elist_Header *elists_ptr,
 245                   struct Elmt_Item *elmts_ptr,
 246                   struct String_Entry *strings_ptr,
 247                   Char_Code *strings_chars_ptr,
 248                   struct List_Header *list_headers_ptr,
 249                   Nat number_file,
 250                   struct File_Info_Type *file_info_ptr,
 251                   Entity_Id standard_boolean,
 252                   Entity_Id standard_integer,
 253                   Entity_Id standard_character,
 254                   Entity_Id standard_long_long_float,
 255                   Entity_Id standard_exception_type,
 256                   Int gigi_operating_mode);
 257
 258 #ifdef __cplusplus
 259 }
 260 #endif
 261
 262 /* GNAT_NODE is the root of some GNAT tree.  Return the root of the
 263    GCC tree corresponding to that GNAT tree.  Normally, no code is generated;
 264    we just return an equivalent tree which is used elsewhere to generate
 265    code.  */
 266 extern tree gnat_to_gnu (Node_Id gnat_node);
 267
 268 /* GNU_STMT is a statement.  We generate code for that statement.  */
 269 extern void gnat_expand_stmt (tree gnu_stmt);
 270
 271 /* Generate GIMPLE in place for the expression at *EXPR_P.  */
 272 extern int gnat_gimplify_expr (tree *expr_p, gimple_seq *pre_p,
 273                                gimple_seq *post_p ATTRIBUTE_UNUSED);
 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.  In the former case, set the Gigi global
 282    variable REF_FILENAME to the simple debug file name as given by sinput.  */
 283 extern bool Sloc_to_locus (Source_Ptr Sloc, location_t *locus);
 284
 285 /* Post an error message.  MSG is the error message, properly annotated.
 286    NODE is the node at which to post the error and the node to use for the
 287    '&' substitution.  */
 288 extern void post_error (const char *msg, Node_Id node);
 289
 290 /* Similar to post_error, but NODE is the node at which to post the error and
 291    ENT is the node to use for the '&' substitution.  */
 292 extern void post_error_ne (const char *msg, Node_Id node, Entity_Id ent);
 293
 294 /* Similar to post_error_ne, but NUM is the number to use for the '^'.  */
 295 extern void post_error_ne_num (const char *msg, Node_Id node, Entity_Id ent,
 296                                int num);
 297
 298 /* Similar to post_error_ne, but T is a GCC tree representing the number to
 299    write.  If T represents a constant, the text inside curly brackets in
 300    MSG will be output (presumably including a '^').  Otherwise it will not
 301    be output and the text inside square brackets will be output instead.  */
 302 extern void post_error_ne_tree (const char *msg, Node_Id node, Entity_Id ent,
 303                                 tree t);
 304
 305 /* Similar to post_error_ne_tree, but NUM is a second integer to write.  */
 306 extern void post_error_ne_tree_2 (const char *msg, Node_Id node, Entity_Id ent,
 307                                   tree t, int num);
 308
 309 /* Return a label to branch to for the exception type in KIND or NULL_TREE
 310    if none.  */
 311 extern tree get_exception_label (char kind);
 312
 313 /* Return the decl for the current elaboration procedure.  */
 314 extern tree get_elaboration_procedure (void);
 315
 316 /* If nonzero, pretend we are allocating at global level.  */
 317 extern int force_global;
 318
 319 /* The default alignment of "double" floating-point types, i.e. floating
 320    point types whose size is equal to 64 bits, or 0 if this alignment is
 321    not specifically capped.  */
 322 extern int double_float_alignment;
 323
 324 /* The default alignment of "double" or larger scalar types, i.e. scalar
 325    types whose size is greater or equal to 64 bits, or 0 if this alignment
 326    is not specifically capped.  */
 327 extern int double_scalar_alignment;
 328 \f
 329 /* Data structures used to represent attributes.  */
 330
 331 enum attr_type
 332 {
 333   ATTR_MACHINE_ATTRIBUTE,
 334   ATTR_LINK_ALIAS,
 335   ATTR_LINK_SECTION,
 336   ATTR_LINK_CONSTRUCTOR,
 337   ATTR_LINK_DESTRUCTOR,
 338   ATTR_THREAD_LOCAL_STORAGE,
 339   ATTR_WEAK_EXTERNAL
 340 };
 341
 342 struct attrib
 343 {
 344   struct attrib *next;
 345   enum attr_type type;
 346   tree name;
 347   tree args;
 348   Node_Id error_point;
 349 };
 350
 351 /* Table of machine-independent internal attributes.  */
 352 extern const struct attribute_spec gnat_internal_attribute_table[];
 353
 354 /* Define the entries in the standard data array.  */
 355 enum standard_datatypes
 356 {
 357   /* The longest floating-point type.  */
 358   ADT_longest_float_type,
 359
 360   /* The type of an exception.  */
 361   ADT_except_type,
 362
 363   /* Type declaration node  <==> typedef void *T */
 364   ADT_ptr_void_type,
 365
 366   /* Function type declaration -- void T() */
 367   ADT_void_ftype,
 368
 369   /* Type declaration node  <==> typedef void *T() */
 370   ADT_ptr_void_ftype,
 371
 372   /* Type declaration node  <==> typedef virtual void *T() */
 373   ADT_fdesc_type,
 374
 375   /* Null pointer for above type.  */
 376   ADT_null_fdesc,
 377
 378   /* Value 1 in signed bitsizetype.  */
 379   ADT_sbitsize_one_node,
 380
 381   /* Value BITS_PER_UNIT in signed bitsizetype.  */
 382   ADT_sbitsize_unit_node,
 383
 384   /* Function declaration nodes for run-time functions for allocating memory.
 385      Ada allocators cause calls to these functions to be generated.  Malloc32
 386      is used only on 64bit systems needing to allocate 32bit memory.  */
 387   ADT_malloc_decl,
 388   ADT_malloc32_decl,
 389
 390   /* Likewise for freeing memory.  */
 391   ADT_free_decl,
 392
 393   /* Function decl node for 64-bit multiplication with overflow checking.  */
 394   ADT_mulv64_decl,
 395
 396   /* Identifier for the name of the _Parent field in tagged record types.  */
 397   ADT_parent_name_id,
 398
 399   /* Identifier for the name of the Exception_Data type.  */
 400   ADT_exception_data_name_id,
 401
 402   /* Types and decls used by our temporary exception mechanism.  See
 403      init_gigi_decls for details.  */
 404   ADT_jmpbuf_type,
 405   ADT_jmpbuf_ptr_type,
 406   ADT_get_jmpbuf_decl,
 407   ADT_set_jmpbuf_decl,
 408   ADT_get_excptr_decl,
 409   ADT_setjmp_decl,
 410   ADT_longjmp_decl,
 411   ADT_update_setjmp_buf_decl,
 412   ADT_raise_nodefer_decl,
 413   ADT_reraise_zcx_decl,
 414   ADT_begin_handler_decl,
 415   ADT_end_handler_decl,
 416   ADT_unhandled_except_decl,
 417   ADT_others_decl,
 418   ADT_all_others_decl,
 419   ADT_unhandled_others_decl,
 420   ADT_LAST};
 421
 422 /* Define kind of exception information associated with raise statements.  */
 423 enum exception_info_kind
 424 {
 425   /* Simple exception information: file:line.  */
 426   exception_simple,
 427   /* Range exception information: file:line + index, first, last.  */
 428   exception_range,
 429   /* Column exception information: file:line:column.  */
 430   exception_column
 431 };
 432
 433 extern GTY(()) tree gnat_std_decls[(int) ADT_LAST];
 434 extern GTY(()) tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
 435 extern GTY(()) tree gnat_raise_decls_ext[(int) LAST_REASON_CODE + 1];
 436
 437 #define longest_float_type_node gnat_std_decls[(int) ADT_longest_float_type]
 438 #define except_type_node gnat_std_decls[(int) ADT_except_type]
 439 #define ptr_void_type_node gnat_std_decls[(int) ADT_ptr_void_type]
 440 #define void_ftype gnat_std_decls[(int) ADT_void_ftype]
 441 #define ptr_void_ftype gnat_std_decls[(int) ADT_ptr_void_ftype]
 442 #define fdesc_type_node gnat_std_decls[(int) ADT_fdesc_type]
 443 #define null_fdesc_node gnat_std_decls[(int) ADT_null_fdesc]
 444 #define sbitsize_one_node gnat_std_decls[(int) ADT_sbitsize_one_node]
 445 #define sbitsize_unit_node gnat_std_decls[(int) ADT_sbitsize_unit_node]
 446 #define malloc_decl gnat_std_decls[(int) ADT_malloc_decl]
 447 #define malloc32_decl gnat_std_decls[(int) ADT_malloc32_decl]
 448 #define free_decl gnat_std_decls[(int) ADT_free_decl]
 449 #define mulv64_decl gnat_std_decls[(int) ADT_mulv64_decl]
 450 #define parent_name_id gnat_std_decls[(int) ADT_parent_name_id]
 451 #define exception_data_name_id gnat_std_decls[(int) ADT_exception_data_name_id]
 452 #define jmpbuf_type gnat_std_decls[(int) ADT_jmpbuf_type]
 453 #define jmpbuf_ptr_type gnat_std_decls[(int) ADT_jmpbuf_ptr_type]
 454 #define get_jmpbuf_decl gnat_std_decls[(int) ADT_get_jmpbuf_decl]
 455 #define set_jmpbuf_decl gnat_std_decls[(int) ADT_set_jmpbuf_decl]
 456 #define get_excptr_decl gnat_std_decls[(int) ADT_get_excptr_decl]
 457 #define setjmp_decl gnat_std_decls[(int) ADT_setjmp_decl]
 458 #define longjmp_decl gnat_std_decls[(int) ADT_longjmp_decl]
 459 #define update_setjmp_buf_decl gnat_std_decls[(int) ADT_update_setjmp_buf_decl]
 460 #define raise_nodefer_decl gnat_std_decls[(int) ADT_raise_nodefer_decl]
 461 #define reraise_zcx_decl gnat_std_decls[(int) ADT_reraise_zcx_decl]
 462 #define begin_handler_decl gnat_std_decls[(int) ADT_begin_handler_decl]
 463 #define others_decl gnat_std_decls[(int) ADT_others_decl]
 464 #define all_others_decl gnat_std_decls[(int) ADT_all_others_decl]
 465 #define unhandled_others_decl gnat_std_decls[(int) ADT_unhandled_others_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
 469 /* Routines expected by the gcc back-end. They must have exactly the same
 470    prototype and names as below.  */
 471
 472 /* Return true if we are in the global binding level.  */
 473 extern bool global_bindings_p (void);
 474
 475 /* Enter and exit a new binding level.  */
 476 extern void gnat_pushlevel (void);
 477 extern void gnat_poplevel (void);
 478 extern void gnat_zaplevel (void);
 479
 480 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
 481    and point FNDECL to this BLOCK.  */
 482 extern void set_current_block_context (tree fndecl);
 483
 484 /* Set the jmpbuf_decl for the current binding level to DECL.  */
 485 extern void set_block_jmpbuf_decl (tree decl);
 486
 487 /* Get the setjmp_decl, if any, for the current binding level.  */
 488 extern tree get_block_jmpbuf_decl (void);
 489
 490 /* Record DECL as belonging to the current lexical scope and use GNAT_NODE
 491    for location information and flag propagation.  */
 492 extern void gnat_pushdecl (tree decl, Node_Id gnat_node);
 493
 494 extern void gnat_init_gcc_eh (void);
 495 extern void gnat_install_builtins (void);
 496
 497 /* Return an integer type with the number of bits of precision given by
 498    PRECISION.  UNSIGNEDP is nonzero if the type is unsigned; otherwise
 499    it is a signed type.  */
 500 extern tree gnat_type_for_size (unsigned precision, int unsignedp);
 501
 502 /* Return a data type that has machine mode MODE.  UNSIGNEDP selects
 503    an unsigned type; otherwise a signed type is returned.  */
 504 extern tree gnat_type_for_mode (enum machine_mode mode, int unsignedp);
 505
 506 /* Emit debug info for all global variable declarations.  */
 507 extern void gnat_write_global_declarations (void);
 508
 509 /* Return the unsigned version of a TYPE_NODE, a scalar type.  */
 510 extern tree gnat_unsigned_type (tree type_node);
 511
 512 /* Return the signed version of a TYPE_NODE, a scalar type.  */
 513 extern tree gnat_signed_type (tree type_node);
 514
 515 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
 516    transparently converted to each other.  */
 517 extern int gnat_types_compatible_p (tree t1, tree t2);
 518
 519 /* Return true if EXPR is a useless type conversion.  */
 520 extern bool gnat_useless_type_conversion (tree expr);
 521
 522 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags.  */
 523 extern bool fntype_same_flags_p (const_tree, tree, bool, bool, bool);
 524
 525 /* Create an expression whose value is that of EXPR,
 526    converted to type TYPE.  The TREE_TYPE of the value
 527    is always TYPE.  This function implements all reasonable
 528    conversions; callers should filter out those that are
 529    not permitted by the language being compiled.  */
 530 extern tree convert (tree type, tree expr);
 531
 532 /* Create an expression whose value is that of EXPR converted to the common
 533    index type, which is sizetype.  */
 534 extern tree convert_to_index_type (tree expr);
 535
 536 /* Routines created solely for the tree translator's sake. Their prototypes
 537    can be changed as desired.  */
 538
 539 /* Initialize data structures of the utils.c module.  */
 540 extern void init_gnat_utils (void);
 541
 542 /* Destroy data structures of the utils.c module.  */
 543 extern void destroy_gnat_utils (void);
 544
 545 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
 546    GNU_DECL is the GCC tree which is to be associated with
 547    GNAT_ENTITY. Such gnu tree node is always an ..._DECL node.
 548    If NO_CHECK is nonzero, the latter check is suppressed.
 549    If GNU_DECL is zero, a previous association is to be reset.  */
 550 extern void save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl,
 551                            bool no_check);
 552
 553 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
 554    Return the ..._DECL node that was associated with it.  If there is no tree
 555    node associated with GNAT_ENTITY, abort.  */
 556 extern tree get_gnu_tree (Entity_Id gnat_entity);
 557
 558 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY.  */
 559 extern bool present_gnu_tree (Entity_Id gnat_entity);
 560
 561 /* Make a dummy type corresponding to GNAT_TYPE.  */
 562 extern tree make_dummy_type (Entity_Id gnat_type);
 563
 564 /* Return the dummy type that was made for GNAT_TYPE, if any.  */
 565 extern tree get_dummy_type (Entity_Id gnat_type);
 566
 567 /* Build dummy fat and thin pointer types whose designated type is specified
 568    by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter.  */
 569 extern void build_dummy_unc_pointer_types (Entity_Id gnat_desig_type,
 570                                            tree gnu_desig_type);
 571
 572 /* Record TYPE as a builtin type for Ada.  NAME is the name of the type.
 573    ARTIFICIAL_P is true if it's a type that was generated by the compiler.  */
 574 extern void record_builtin_type (const char *name, tree type,
 575                                  bool artificial_p);
 576
 577 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
 578    finish constructing the record type as a fat pointer type.  */
 579 extern void finish_fat_pointer_type (tree record_type, tree field_list);
 580
 581 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
 582    finish constructing the record or union type.  If REP_LEVEL is zero, this
 583    record has no representation clause and so will be entirely laid out here.
 584    If REP_LEVEL is one, this record has a representation clause and has been
 585    laid out already; only set the sizes and alignment.  If REP_LEVEL is two,
 586    this record is derived from a parent record and thus inherits its layout;
 587    only make a pass on the fields to finalize them.  DEBUG_INFO_P is true if
 588    we need to write debug information about this type.  */
 589 extern void finish_record_type (tree record_type, tree field_list,
 590                                 int rep_level, bool debug_info_p);
 591
 592 /* Wrap up compilation of RECORD_TYPE, i.e. output all the debug information
 593    associated with it.  It need not be invoked directly in most cases since
 594    finish_record_type takes care of doing so, but this can be necessary if
 595    a parallel type is to be attached to the record type.  */
 596 extern void rest_of_record_type_compilation (tree record_type);
 597
 598 /* Append PARALLEL_TYPE on the chain of parallel types for TYPE.  */
 599 extern void add_parallel_type (tree type, tree parallel_type);
 600
 601 /* Return a FUNCTION_TYPE node.  RETURN_TYPE is the type returned by the
 602    subprogram.  If it is VOID_TYPE, then we are dealing with a procedure,
 603    otherwise we are dealing with a function.  PARAM_DECL_LIST is a list of
 604    PARM_DECL nodes that are the subprogram parameters.  CICO_LIST is the
 605    copy-in/copy-out list to be stored into the TYPE_CICO_LIST field.
 606    RETURN_UNCONSTRAINED_P is true if the function returns an unconstrained
 607    object.  RETURN_BY_DIRECT_REF_P is true if the function returns by direct
 608    reference.  RETURN_BY_INVISI_REF_P is true if the function returns by
 609    invisible reference.  */
 610 extern tree create_subprog_type (tree return_type, tree param_decl_list,
 611                                  tree cico_list, bool return_unconstrained_p,
 612                                  bool return_by_direct_ref_p,
 613                                  bool return_by_invisi_ref_p);
 614
 615 /* Return a copy of TYPE, but safe to modify in any way.  */
 616 extern tree copy_type (tree type);
 617
 618 /* Return a subtype of sizetype with range MIN to MAX and whose
 619    TYPE_INDEX_TYPE is INDEX.  GNAT_NODE is used for the position
 620    of the associated TYPE_DECL.  */
 621 extern tree create_index_type (tree min, tree max, tree index,
 622                                Node_Id gnat_node);
 623
 624 /* Return a subtype of TYPE with range MIN to MAX.  If TYPE is NULL,
 625    sizetype is used.  */
 626 extern tree create_range_type (tree type, tree min, tree max);
 627
 628 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of a type.
 629    TYPE_NAME gives the name of the type and TYPE is a ..._TYPE node giving
 630    its data type.  */
 631 extern tree create_type_stub_decl (tree type_name, tree type);
 632
 633 /* Return a TYPE_DECL node.  TYPE_NAME gives the name of the type and TYPE
 634    is a ..._TYPE node giving its data type.  ARTIFICIAL_P is true if this
 635    is a declaration that was generated by the compiler.  DEBUG_INFO_P is
 636    true if we need to write debug information about this type.  GNAT_NODE
 637    is used for the position of the decl.  */
 638 extern tree create_type_decl (tree type_name, tree type,
 639                               struct attrib *attr_list,
 640                               bool artificial_p, bool debug_info_p,
 641                               Node_Id gnat_node);
 642
 643 /* Return a VAR_DECL or CONST_DECL node.
 644
 645    VAR_NAME gives the name of the variable.  ASM_NAME is its assembler name
 646    (if provided).  TYPE is its data type (a GCC ..._TYPE node).  VAR_INIT is
 647    the GCC tree for an optional initial expression; NULL_TREE if none.
 648
 649    CONST_FLAG is true if this variable is constant, in which case we might
 650    return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
 651
 652    PUBLIC_FLAG is true if this definition is to be made visible outside of
 653    the current compilation unit. This flag should be set when processing the
 654    variable definitions in a package specification.
 655
 656    EXTERN_FLAG is nonzero when processing an external variable declaration (as
 657    opposed to a definition: no storage is to be allocated for the variable).
 658
 659    STATIC_FLAG is only relevant when not at top level.  In that case
 660    it indicates whether to always allocate storage to the variable.
 661
 662    GNAT_NODE is used for the position of the decl.  */
 663 extern tree
 664 create_var_decl_1 (tree var_name, tree asm_name, tree type, tree var_init,
 665                    bool const_flag, bool public_flag, bool extern_flag,
 666                    bool static_flag, bool const_decl_allowed_p,
 667                    struct attrib *attr_list, Node_Id gnat_node);
 668
 669 /* Wrapper around create_var_decl_1 for cases where we don't care whether
 670    a VAR or a CONST decl node is created.  */
 671 #define create_var_decl(var_name, asm_name, type, var_init,     \
 672                         const_flag, public_flag, extern_flag,   \
 673                         static_flag, attr_list, gnat_node)      \
 674   create_var_decl_1 (var_name, asm_name, type, var_init,        \
 675                      const_flag, public_flag, extern_flag,      \
 676                      static_flag, true, attr_list, gnat_node)
 677
 678 /* Wrapper around create_var_decl_1 for cases where a VAR_DECL node is
 679    required.  The primary intent is for DECL_CONST_CORRESPONDING_VARs, which
 680    must be VAR_DECLs and on which we want TREE_READONLY set to have them
 681    possibly assigned to a readonly data section.  */
 682 #define create_true_var_decl(var_name, asm_name, type, var_init,        \
 683                              const_flag, public_flag, extern_flag,      \
 684                              static_flag, attr_list, gnat_node)         \
 685   create_var_decl_1 (var_name, asm_name, type, var_init,                \
 686                      const_flag, public_flag, extern_flag,              \
 687                      static_flag, false, attr_list, gnat_node)
 688
 689 /* Record DECL as a global renaming pointer.  */
 690 extern void record_global_renaming_pointer (tree decl);
 691
 692 /* Invalidate the global renaming pointers.  */
 693 extern void invalidate_global_renaming_pointers (void);
 694
 695 /* Return a FIELD_DECL node.  FIELD_NAME is the field's name, FIELD_TYPE is
 696    its type and RECORD_TYPE is the type of the enclosing record.  If SIZE is
 697    nonzero, it is the specified size of the field.  If POS is nonzero, it is
 698    the bit position.  PACKED is 1 if the enclosing record is packed, -1 if it
 699    has Component_Alignment of Storage_Unit.  If ADDRESSABLE is nonzero, it
 700    means we are allowed to take the address of the field; if it is negative,
 701    we should not make a bitfield, which is used by make_aligning_type.  */
 702 extern tree create_field_decl (tree field_name, tree field_type,
 703                                tree record_type, tree size, tree pos,
 704                                int packed, int addressable);
 705
 706 /* Return a PARM_DECL node.  PARAM_NAME is the name of the parameter and
 707    PARAM_TYPE is its type.  READONLY is true if the parameter is readonly
 708    (either an In parameter or an address of a pass-by-ref parameter).  */
 709 extern tree create_param_decl (tree param_name, tree param_type,
 710                                bool readonly);
 711
 712 /* Return a LABEL_DECL with LABEL_NAME.  GNAT_NODE is used for the position
 713    of the decl.  */
 714 extern tree create_label_decl (tree, Node_Id);
 715
 716 /* Return a FUNCTION_DECL node.  SUBPROG_NAME is the name of the subprogram,
 717    ASM_NAME is its assembler name, SUBPROG_TYPE is its type (a FUNCTION_TYPE
 718    node), PARAM_DECL_LIST is the list of the subprogram arguments (a list of
 719    PARM_DECL nodes chained through the DECL_CHAIN field).
 720
 721    INLINE_FLAG, PUBLIC_FLAG, EXTERN_FLAG, ARTIFICIAL_FLAG and ATTR_LIST are
 722    used to set the appropriate fields in the FUNCTION_DECL.  GNAT_NODE is
 723    used for the position of the decl.  */
 724 extern tree create_subprog_decl (tree subprog_name, tree asm_name,
 725                                  tree subprog_type, tree param_decl_list,
 726                                  bool inline_flag, bool public_flag,
 727                                  bool extern_flag, bool artificial_flag,
 728                                  struct attrib *attr_list, Node_Id gnat_node);
 729
 730 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
 731    body. This routine needs to be invoked before processing the declarations
 732    appearing in the subprogram.  */
 733 extern void begin_subprog_body (tree subprog_decl);
 734
 735 /* Finish translating the current subprogram and set its BODY.  */
 736 extern void end_subprog_body (tree body);
 737
 738 /* Wrap up compilation of SUBPROG_DECL, a subprogram body.  */
 739 extern void rest_of_subprog_body_compilation (tree subprog_decl);
 740
 741 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
 742    EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
 743    Return a constructor for the template.  */
 744 extern tree build_template (tree template_type, tree array_type, tree expr);
 745
 746 /* Build a 64bit VMS descriptor from a Mechanism_Type, which must specify
 747    a descriptor type, and the GCC type of an object.  Each FIELD_DECL
 748    in the type contains in its DECL_INITIAL the expression to use when
 749    a constructor is made for the type.  GNAT_ENTITY is a gnat node used
 750    to print out an error message if the mechanism cannot be applied to
 751    an object of that type and also for the name.  */
 752 extern tree build_vms_descriptor (tree type, Mechanism_Type mech,
 753                                   Entity_Id gnat_entity);
 754
 755 /* Build a 32bit VMS descriptor from a Mechanism_Type. See above.  */
 756 extern tree build_vms_descriptor32 (tree type, Mechanism_Type mech,
 757                                   Entity_Id gnat_entity);
 758
 759 /* Build a type to be used to represent an aliased object whose nominal type
 760    is an unconstrained array.  This consists of a RECORD_TYPE containing a
 761    field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
 762    If ARRAY_TYPE is that of an unconstrained array, this is used to represent
 763    an arbitrary unconstrained object.  Use NAME as the name of the record.
 764    DEBUG_INFO_P is true if we need to write debug information for the type.  */
 765 extern tree build_unc_object_type (tree template_type, tree object_type,
 766                                    tree name, bool debug_info_p);
 767
 768 /* Same as build_unc_object_type, but taking a thin or fat pointer type
 769    instead of the template type.  */
 770 extern tree build_unc_object_type_from_ptr (tree thin_fat_ptr_type,
 771                                             tree object_type, tree name,
 772                                             bool debug_info_p);
 773
 774 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.  In
 775    the normal case this is just two adjustments, but we have more to do
 776    if NEW is an UNCONSTRAINED_ARRAY_TYPE.  */
 777 extern void update_pointer_to (tree old_type, tree new_type);
 778
 779 /* EXP is an expression for the size of an object.  If this size contains
 780    discriminant references, replace them with the maximum (if MAX_P) or
 781    minimum (if !MAX_P) possible value of the discriminant.  */
 782 extern tree max_size (tree exp, bool max_p);
 783
 784 /* Remove all conversions that are done in EXP.  This includes converting
 785    from a padded type or to a left-justified modular type.  If TRUE_ADDRESS
 786    is true, always return the address of the containing object even if
 787    the address is not bit-aligned.  */
 788 extern tree remove_conversions (tree exp, bool true_address);
 789
 790 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
 791    refers to the underlying array.  If its type has TYPE_CONTAINS_TEMPLATE_P,
 792    likewise return an expression pointing to the underlying array.  */
 793 extern tree maybe_unconstrained_array (tree exp);
 794
 795 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
 796    If NOTRUNC_P is true, truncation operations should be suppressed.  */
 797 extern tree unchecked_convert (tree type, tree expr, bool notrunc_p);
 798
 799 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
 800    the latter being a record type as predicated by Is_Record_Type.  */
 801 extern enum tree_code tree_code_for_record_type (Entity_Id gnat_type);
 802
 803 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
 804    size is equal to 64 bits, or an array of such a type.  Set ALIGN_CLAUSE
 805    according to the presence of an alignment clause on the type or, if it
 806    is an array, on the component type.  */
 807 extern bool is_double_float_or_array (Entity_Id gnat_type,
 808                                       bool *align_clause);
 809
 810 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
 811    size is greater or equal to 64 bits, or an array of such a type.  Set
 812    ALIGN_CLAUSE according to the presence of an alignment clause on the
 813    type or, if it is an array, on the component type.  */
 814 extern bool is_double_scalar_or_array (Entity_Id gnat_type,
 815                                        bool *align_clause);
 816
 817 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
 818    component of an aggregate type.  */
 819 extern bool type_for_nonaliased_component_p (tree gnu_type);
 820
 821 /* Return true if TYPE is a smaller form of ORIG_TYPE.  */
 822 extern bool smaller_form_type_p (tree type, tree orig_type);
 823
 824 /* Return the base type of TYPE.  */
 825 extern tree get_base_type (tree type);
 826
 827 /* EXP is a GCC tree representing an address.  See if we can find how
 828    strictly the object at that address is aligned.   Return that alignment
 829    strictly the object at that address is aligned.   Return that alignment
 830    in bits.  If we don't know anything about the alignment, return 0.  */
 831 extern unsigned int known_alignment (tree exp);
 832
 833 /* Return true if VALUE is a multiple of FACTOR. FACTOR must be a power
 834    of 2.  */
 835 extern bool value_factor_p (tree value, HOST_WIDE_INT factor);
 836
 837 /* Build an atomic load for the underlying atomic object in SRC.  */
 838 extern tree build_atomic_load (tree src);
 839
 840 /* Build an atomic store from SRC to the underlying atomic object in DEST.  */
 841 extern tree build_atomic_store (tree dest, tree src);
 842
 843 /* Make a binary operation of kind OP_CODE.  RESULT_TYPE is the type
 844    desired for the result.  Usually the operation is to be performed
 845    in that type.  For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
 846    in which case the type to be used will be derived from the operands.  */
 847 extern tree build_binary_op (enum tree_code op_code, tree result_type,
 848                              tree left_operand, tree right_operand);
 849
 850 /* Similar, but make unary operation.  */
 851 extern tree build_unary_op (enum tree_code op_code, tree result_type,
 852                             tree operand);
 853
 854 /* Similar, but for COND_EXPR.  */
 855 extern tree build_cond_expr (tree result_type, tree condition_operand,
 856                              tree true_operand, tree false_operand);
 857
 858 /* Similar, but for COMPOUND_EXPR.  */
 859 extern tree build_compound_expr (tree result_type, tree stmt_operand,
 860                                  tree expr_operand);
 861
 862 /* Conveniently construct a function call expression.  FNDECL names the
 863    function to be called, N is the number of arguments, and the "..."
 864    parameters are the argument expressions.  Unlike build_call_expr
 865    this doesn't fold the call, hence it will always return a CALL_EXPR.  */
 866 extern tree build_call_n_expr (tree fndecl, int n, ...);
 867
 868 /* Call a function that raises an exception and pass the line number and file
 869    name, if requested.  MSG says which exception function to call.
 870
 871    GNAT_NODE is the gnat node conveying the source location for which the
 872    error should be signaled, or Empty in which case the error is signaled on
 873    the current ref_file_name/input_line.
 874
 875    KIND says which kind of exception this is for
 876     (N_Raise_{Constraint,Storage,Program}_Error).  */
 877 extern tree build_call_raise (int msg, Node_Id gnat_node, char kind);
 878
 879 /* Similar to build_call_raise, for an index or range check exception as
 880    determined by MSG, with extra information generated of the form
 881    "INDEX out of range FIRST..LAST".  */
 882 extern tree build_call_raise_range (int msg, Node_Id gnat_node,
 883                                     tree index, tree first, tree last);
 884
 885 /* Similar to build_call_raise, with extra information about the column
 886    where the check failed.  */
 887 extern tree build_call_raise_column (int msg, Node_Id gnat_node);
 888
 889 /* Return a CONSTRUCTOR of TYPE whose elements are V.  This is not the
 890    same as build_constructor in the language-independent tree.c.  */
 891 extern tree gnat_build_constructor (tree type, vec<constructor_elt, va_gc> *v);
 892
 893 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
 894    an IDENTIFIER_NODE giving the name of the field, FIELD, a FIELD_DECL,
 895    for the field, or both.  Don't fold the result if NO_FOLD_P.  */
 896 extern tree build_component_ref (tree record_variable, tree component,
 897                                  tree field, bool no_fold_p);
 898
 899 /* Build a GCC tree to call an allocation or deallocation function.
 900    If GNU_OBJ is nonzero, it is an object to deallocate.  Otherwise,
 901    generate an allocator.
 902
 903    GNU_SIZE is the number of bytes to allocate and GNU_TYPE is the contained
 904    object type, used to determine the to-be-honored address alignment.
 905    GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the storage
 906    pool to use.  If not present, malloc and free are used.  GNAT_NODE is used
 907    to provide an error location for restriction violation messages.  */
 908 extern tree build_call_alloc_dealloc (tree gnu_obj, tree gnu_size,
 909                                       tree gnu_type, Entity_Id gnat_proc,
 910                                       Entity_Id gnat_pool, Node_Id gnat_node);
 911
 912 /* Build a GCC tree to correspond to allocating an object of TYPE whose
 913    initial value if INIT, if INIT is nonzero.  Convert the expression to
 914    RESULT_TYPE, which must be some type of pointer.  Return the tree.
 915
 916    GNAT_PROC and GNAT_POOL optionally give the procedure to call and
 917    the storage pool to use.  GNAT_NODE is used to provide an error
 918    location for restriction violation messages.  If IGNORE_INIT_TYPE is
 919    true, ignore the type of INIT for the purpose of determining the size;
 920    this will cause the maximum size to be allocated if TYPE is of
 921    self-referential size.  */
 922 extern tree build_allocator (tree type, tree init, tree result_type,
 923                              Entity_Id gnat_proc, Entity_Id gnat_pool,
 924                              Node_Id gnat_node, bool);
 925
 926 /* Fill in a VMS descriptor of GNU_TYPE for GNU_EXPR and return the result.
 927    GNAT_ACTUAL is the actual parameter for which the descriptor is built.  */
 928 extern tree fill_vms_descriptor (tree gnu_type, tree gnu_expr,
 929                                  Node_Id gnat_actual);
 930
 931 /* Convert GNU_EXPR, a pointer to a VMS descriptor, to GNU_TYPE, a regular
 932    pointer or fat pointer type.  GNU_EXPR_ALT_TYPE is the alternate (32-bit)
 933    pointer type of GNU_EXPR.  BY_REF is true if the result is to be used by
 934    reference.  GNAT_SUBPROG is the subprogram to which the VMS descriptor is
 935    passed.  */
 936 extern tree convert_vms_descriptor (tree gnu_type, tree gnu_expr,
 937                                     tree gnu_expr_alt_type, bool by_ref,
 938                                     Entity_Id gnat_subprog);
 939
 940 /* Indicate that we need to take the address of T and that it therefore
 941    should not be allocated in a register.  Returns true if successful.  */
 942 extern bool gnat_mark_addressable (tree t);
 943
 944 /* Save EXP for later use or reuse.  This is equivalent to save_expr in tree.c
 945    but we know how to handle our own nodes.  */
 946 extern tree gnat_save_expr (tree exp);
 947
 948 /* Protect EXP for immediate reuse.  This is a variant of gnat_save_expr that
 949    is optimized under the assumption that EXP's value doesn't change before
 950    its subsequent reuse(s) except through its potential reevaluation.  */
 951 extern tree gnat_protect_expr (tree exp);
 952
 953 /* This is equivalent to stabilize_reference in tree.c but we know how to
 954    handle our own nodes and we take extra arguments.  FORCE says whether to
 955    force evaluation of everything.  We set SUCCESS to true unless we walk
 956    through something we don't know how to stabilize.  */
 957 extern tree gnat_stabilize_reference (tree ref, bool force, bool *success);
 958
 959 /* If EXPR is an expression that is invariant in the current function, in the
 960    sense that it can be evaluated anywhere in the function and any number of
 961    times, return EXPR or an equivalent expression.  Otherwise return NULL.  */
 962 extern tree gnat_invariant_expr (tree expr);
 963
 964 /* Implementation of the builtin_function langhook.  */
 965 extern tree gnat_builtin_function (tree decl);
 966
 967 /* Search the chain of currently reachable declarations for a builtin
 968    FUNCTION_DECL node corresponding to function NAME (an IDENTIFIER_NODE).
 969    Return the first node found, if any, or NULL_TREE otherwise.  */
 970 extern tree builtin_decl_for (tree name);
 971
 972 /* GNU_TYPE is a type. Determine if it should be passed by reference by
 973    default.  */
 974 extern bool default_pass_by_ref (tree gnu_type);
 975
 976 /* GNU_TYPE is the type of a subprogram parameter.  Determine from the type
 977    if it should be passed by reference.  */
 978 extern bool must_pass_by_ref (tree gnu_type);
 979
 980 /* Return the size of the FP mode with precision PREC.  */
 981 extern int fp_prec_to_size (int prec);
 982
 983 /* Return the precision of the FP mode with size SIZE.  */
 984 extern int fp_size_to_prec (int size);
 985
 986 #ifdef __cplusplus
 987 extern "C" {
 988 #endif
 989
 990 /* These functions return the basic data type sizes and related parameters
 991    about the target machine.  */
 992 extern Pos get_target_bits_per_unit (void);
 993 extern Pos get_target_bits_per_word (void);
 994 extern Pos get_target_char_size (void);
 995 extern Pos get_target_wchar_t_size (void);
 996 extern Pos get_target_short_size (void);
 997 extern Pos get_target_int_size (void);
 998 extern Pos get_target_long_size (void);
 999 extern Pos get_target_long_long_size (void);
1000 extern Pos get_target_float_size (void);
1001 extern Pos get_target_double_size (void);
1002 extern Pos get_target_long_double_size (void);
1003 extern Pos get_target_pointer_size (void);
1004 extern Pos get_target_maximum_default_alignment (void);
1005 extern Pos get_target_system_allocator_alignment (void);
1006 extern Pos get_target_maximum_allowed_alignment (void);
1007 extern Pos get_target_maximum_alignment (void);
1008 extern Nat get_float_words_be (void);
1009 extern Nat get_words_be (void);
1010 extern Nat get_bytes_be (void);
1011 extern Nat get_bits_be (void);
1012 extern Nat get_target_strict_alignment (void);
1013 extern Nat get_target_double_float_alignment (void);
1014 extern Nat get_target_double_scalar_alignment (void);
1015
1016 /* This function is called by the front-end to enumerate all the supported
1017    modes for the machine, as well as some predefined C types.  */
1018 extern void enumerate_modes (void (*f) (const char *, int, int, int, int, int,
1019                                         int));
1020
1021 #ifdef __cplusplus
1022 }
1023 #endif
1024
1025 /* Let code know whether we are targetting VMS without need of
1026    intrusive preprocessor directives.  */
1027 #ifndef TARGET_ABI_OPEN_VMS
1028 #define TARGET_ABI_OPEN_VMS 0
1029 #endif
1030
1031 /* VMS option set by default, when clear forces 32bit mallocs and 32bit
1032    Descriptors.  Always used in combination with TARGET_ABI_OPEN_VMS
1033    so no effect on non-VMS systems.  */
1034 #if TARGET_ABI_OPEN_VMS == 0
1035 #define flag_vms_malloc64 0
1036 #endif
1037
1038 /* Convenient shortcuts.  */
1039 #define VECTOR_TYPE_P(TYPE) (TREE_CODE (TYPE) == VECTOR_TYPE)
1040
1041 /* If EXP's type is a VECTOR_TYPE, return EXP converted to the associated
1042    TYPE_REPRESENTATIVE_ARRAY.  */
1043
1044 static inline tree
1045 maybe_vector_array (tree exp)
1046 {
1047   tree etype = TREE_TYPE (exp);
1048
1049   if (VECTOR_TYPE_P (etype))
1050     exp = convert (TYPE_REPRESENTATIVE_ARRAY (etype), exp);
1051
1052   return exp;
1053 }
1054
1055 static inline unsigned HOST_WIDE_INT
1056 ceil_pow2 (unsigned HOST_WIDE_INT x)
1057 {
1058   return (unsigned HOST_WIDE_INT) 1 << (floor_log2 (x - 1) + 1);
1059 }