gcc/ada/gigi.h

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                                 G I G I                                  *
   6  *                                                                          *
   7  *                              C Header File                               *
   8  *                                                                          *
   9  *          Copyright (C) 1992-2008, 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 2,  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 COPYING.  If not, write *
  19  * to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, *
  20  * Boston, MA 02110-1301, USA.                                              *
  21  *                                                                          *
  22  * As a  special  exception,  if you  link  this file  with other  files to *
  23  * produce an executable,  this file does not by itself cause the resulting *
  24  * executable to be covered by the GNU General Public License. This except- *
  25  * ion does not  however invalidate  any other reasons  why the  executable *
  26  * file might be covered by the  GNU Public License.                        *
  27  *                                                                          *
  28  * GNAT was originally developed  by the GNAT team at  New York University. *
  29  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  30  *                                                                          *
  31  ****************************************************************************/
  32
  33 /* Declare all functions and types used by gigi.  */
  34
  35 /* The largest alignment, in bits, that is needed for using the widest
  36    move instruction.  */
  37 extern unsigned int largest_move_alignment;
  38
  39 /* Compute the alignment of the largest mode that can be used for copying
  40    objects.  */
  41 extern void gnat_compute_largest_alignment (void);
  42
  43 /* GNU_TYPE is a type. Determine if it should be passed by reference by
  44    default.  */
  45 extern bool default_pass_by_ref (tree gnu_type);
  46
  47 /* GNU_TYPE is the type of a subprogram parameter.  Determine from the type
  48    if it should be passed by reference.  */
  49 extern bool must_pass_by_ref (tree gnu_type);
  50
  51 /* Initialize DUMMY_NODE_TABLE.  */
  52 extern void init_dummy_type (void);
  53
  54 /* Given GNAT_ENTITY, an entity in the incoming GNAT tree, return a
  55    GCC type corresponding to that entity.  GNAT_ENTITY is assumed to
  56    refer to an Ada type.  */
  57 extern tree gnat_to_gnu_type (Entity_Id gnat_entity);
  58
  59 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
  60    entity, this routine returns the equivalent GCC tree for that entity
  61    (an ..._DECL node) and associates the ..._DECL node with the input GNAT
  62    defining identifier.
  63
  64    If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
  65    initial value (in GCC tree form). This is optional for variables.
  66    For renamed entities, GNU_EXPR gives the object being renamed.
  67
  68    DEFINITION is nonzero if this call is intended for a definition.  This is
  69    used for separate compilation where it necessary to know whether an
  70    external declaration or a definition should be created if the GCC equivalent
  71    was not created previously.  The value of 1 is normally used for a nonzero
  72    DEFINITION, but a value of 2 is used in special circumstances, defined in
  73    the code.  */
  74 extern tree gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr,
  75                                 int definition);
  76
  77 /* Similar, but if the returned value is a COMPONENT_REF, return the
  78    FIELD_DECL.  */
  79 extern tree gnat_to_gnu_field_decl (Entity_Id gnat_entity);
  80
  81 /* Wrap up compilation of T, a TYPE_DECL, possibly deferring it.  */
  82 extern void rest_of_type_decl_compilation (tree t);
  83
  84 /* Start a new statement group chained to the previous group.  */
  85 extern void start_stmt_group (void);
  86
  87 /* Add GNU_STMT to the current BLOCK_STMT node.  */
  88 extern void add_stmt (tree gnu_stmt);
  89
  90 /* Similar, but set the location of GNU_STMT to that of GNAT_NODE.  */
  91 extern void add_stmt_with_node (tree gnu_stmt, Node_Id gnat_node);
  92
  93 /* Return code corresponding to the current code group.  It is normally
  94    a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if
  95    BLOCK or cleanups were set.  */
  96 extern tree end_stmt_group (void);
  97
  98 /* Set the BLOCK node corresponding to the current code group to GNU_BLOCK.  */
  99 extern void set_block_for_group (tree);
 100
 101 /* Add a declaration statement for GNU_DECL to the current BLOCK_STMT node.
 102    Get SLOC from GNAT_ENTITY.  */
 103 extern void add_decl_expr (tree gnu_decl, Entity_Id gnat_entity);
 104
 105 /* Finalize any From_With_Type incomplete types.  We do this after processing
 106    our compilation unit and after processing its spec, if this is a body.  */
 107 extern void finalize_from_with_types (void);
 108
 109 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a
 110    kind of type (such E_Task_Type) that has a different type which Gigi
 111    uses for its representation.  If the type does not have a special type
 112    for its representation, return GNAT_ENTITY.  If a type is supposed to
 113    exist, but does not, abort unless annotating types, in which case
 114    return Empty.   If GNAT_ENTITY is Empty, return Empty.  */
 115 extern Entity_Id Gigi_Equivalent_Type (Entity_Id);
 116
 117 /* Given GNAT_ENTITY, elaborate all expressions that are required to
 118    be elaborated at the point of its definition, but do nothing else.  */
 119 extern void elaborate_entity (Entity_Id gnat_entity);
 120
 121 /* Mark GNAT_ENTITY as going out of scope at this point.  Recursively mark
 122    any entities on its entity chain similarly.  */
 123 extern void mark_out_of_scope (Entity_Id gnat_entity);
 124
 125 /* Make a dummy type corresponding to GNAT_TYPE.  */
 126 extern tree make_dummy_type (Entity_Id gnat_type);
 127
 128 /* Get the unpadded version of a GNAT type.  */
 129 extern tree get_unpadded_type (Entity_Id gnat_entity);
 130
 131 /* Called when we need to protect a variable object using a save_expr.  */
 132 extern tree maybe_variable (tree gnu_operand);
 133
 134 /* Create a record type that contains a SIZE bytes long field of TYPE with a
 135     starting bit position so that it is aligned to ALIGN bits, and leaving at
 136     least ROOM bytes free before the field.  BASE_ALIGN is the alignment the
 137     record is guaranteed to get.  */
 138 extern tree make_aligning_type (tree type, unsigned int align, tree size,
 139                                 unsigned int base_align, int room);
 140
 141 /* Ensure that TYPE has SIZE and ALIGN.  Make and return a new padded type
 142    if needed.  We have already verified that SIZE and TYPE are large enough.
 143
 144    GNAT_ENTITY and NAME_TRAILER are used to name the resulting record and
 145    to issue a warning.
 146
 147    IS_USER_TYPE is true if we must be sure we complete the original type.
 148
 149    DEFINITION is true if this type is being defined.
 150
 151    SAME_RM_SIZE is true if the RM_Size of the resulting type is to be
 152    set to its TYPE_SIZE; otherwise, it's set to the RM_Size of the original
 153    type.  */
 154 extern tree maybe_pad_type (tree type, tree size, unsigned int align,
 155                             Entity_Id gnat_entity, const char *name_trailer,
 156                             bool is_user_type, bool definition,
 157                             bool same_rm_size);
 158
 159 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
 160    the value passed against the list of choices.  */
 161 extern tree choices_to_gnu (tree operand, Node_Id choices);
 162
 163 /* Given a type T, a FIELD_DECL F, and a replacement value R, return a new
 164    type with all size expressions that contain F updated by replacing F
 165    with R.  If F is NULL_TREE, always make a new RECORD_TYPE, even if
 166    nothing has changed.  */
 167 extern tree substitute_in_type (tree t, tree f, tree r);
 168
 169 /* Return the "RM size" of GNU_TYPE.  This is the actual number of bits
 170    needed to represent the object.  */
 171 extern tree rm_size (tree gnu_type);
 172
 173 /* Given GNU_ID, an IDENTIFIER_NODE containing a name, and SUFFIX, a
 174    string, return a new IDENTIFIER_NODE that is the concatenation of
 175    the name in GNU_ID and SUFFIX.  */
 176 extern tree concat_id_with_name (tree gnu_id, const char *suffix);
 177
 178 /* Return the name to be used for GNAT_ENTITY.  If a type, create a
 179    fully-qualified name, possibly with type information encoding.
 180    Otherwise, return the name.  */
 181 extern tree get_entity_name (Entity_Id gnat_entity);
 182
 183 /* Return a name for GNAT_ENTITY concatenated with two underscores and
 184    SUFFIX.  */
 185 extern tree create_concat_name (Entity_Id gnat_entity, const char *suffix);
 186
 187 /* If true, then gigi is being called on an analyzed but unexpanded tree, and
 188    the only purpose of the call is to properly annotate types with
 189    representation information.  */
 190 extern bool type_annotate_only;
 191
 192 /* Current file name without path */
 193 extern const char *ref_filename;
 194
 195 /* This structure must be kept synchronized with Call_Back_End.  */
 196 struct File_Info_Type
 197 {
 198   File_Name_Type File_Name;
 199   Nat Num_Source_Lines;
 200 };
 201
 202 /* This is the main program of the back-end.  It sets up all the table
 203    structures and then generates code.
 204
 205    ??? Needs parameter descriptions  */
 206
 207 extern void gigi (Node_Id gnat_root, int max_gnat_node, int number_name,
 208                   struct Node *nodes_ptr, Node_Id *next_node_ptr,
 209                   Node_Id *prev_node_ptr, struct Elist_Header *elists_ptr,
 210                   struct Elmt_Item *elmts_ptr,
 211                   struct String_Entry *strings_ptr,
 212                   Char_Code *strings_chars_ptr,
 213                   struct List_Header *list_headers_ptr,
 214                   Nat number_file,
 215                   struct File_Info_Type *file_info_ptr ATTRIBUTE_UNUSED,
 216                   Entity_Id standard_integer,
 217                   Entity_Id standard_long_long_float,
 218                   Entity_Id standard_exception_type,
 219                   Int gigi_operating_mode);
 220
 221 /* GNAT_NODE is the root of some GNAT tree.  Return the root of the
 222    GCC tree corresponding to that GNAT tree.  Normally, no code is generated;
 223    we just return an equivalent tree which is used elsewhere to generate
 224    code.  */
 225 extern tree gnat_to_gnu (Node_Id gnat_node);
 226
 227 /* GNU_STMT is a statement.  We generate code for that statement.  */
 228 extern void gnat_expand_stmt (tree gnu_stmt);
 229
 230 /* ??? missing documentation */
 231 extern int gnat_gimplify_expr (tree *expr_p, tree *pre_p,
 232                                tree *post_p ATTRIBUTE_UNUSED);
 233
 234 /* Do the processing for the declaration of a GNAT_ENTITY, a type.  If
 235    a separate Freeze node exists, delay the bulk of the processing.  Otherwise
 236    make a GCC type for GNAT_ENTITY and set up the correspondence.  */
 237 extern void process_type (Entity_Id gnat_entity);
 238
 239 /* Convert SLOC into LOCUS.  Return true if SLOC corresponds to a source code
 240    location and false if it doesn't.  In the former case, set the Gigi global
 241    variable REF_FILENAME to the simple debug file name as given by sinput.  */
 242 extern bool Sloc_to_locus (Source_Ptr Sloc, location_t *locus);
 243
 244 /* Post an error message.  MSG is the error message, properly annotated.
 245    NODE is the node at which to post the error and the node to use for the
 246    "&" substitution.  */
 247 extern void post_error (const char *, Node_Id);
 248
 249 /* Similar, but NODE is the node at which to post the error and ENT
 250    is the node to use for the "&" substitution.  */
 251 extern void post_error_ne (const char *msg, Node_Id node, Entity_Id ent);
 252
 253 /* Similar, but NODE is the node at which to post the error, ENT is the node
 254    to use for the "&" substitution, and N is the number to use for the ^.  */
 255 extern void post_error_ne_num (const char *msg, Node_Id node, Entity_Id ent,
 256                                int n);
 257
 258 /* Similar to post_error_ne_num, but T is a GCC tree representing the number
 259    to write.  If the tree represents a constant that fits within a
 260    host integer, the text inside curly brackets in MSG will be output
 261    (presumably including a '^').  Otherwise that text will not be output
 262    and the text inside square brackets will be output instead.  */
 263 extern void post_error_ne_tree (const char *msg, Node_Id node, Entity_Id ent,
 264                                 tree t);
 265
 266 /* Similar to post_error_ne_tree, except that NUM is a second
 267    integer to write in the message.  */
 268 extern void post_error_ne_tree_2 (const char *msg, Node_Id node, Entity_Id ent,
 269                                   tree t, int num);
 270
 271 /* Protect EXP from multiple evaluation.  This may make a SAVE_EXPR.  */
 272 extern tree protect_multiple_eval (tree exp);
 273
 274 /* Return a label to branch to for the exception type in KIND or NULL_TREE
 275    if none.  */
 276 extern tree get_exception_label (char);
 277
 278 /* Current node being treated, in case gigi_abort or Check_Elaboration_Code
 279    called.  */
 280 extern Node_Id error_gnat_node;
 281
 282 /* This is equivalent to stabilize_reference in tree.c, but we know how to
 283    handle our own nodes and we take extra arguments.  FORCE says whether to
 284    force evaluation of everything.  We set SUCCESS to true unless we walk
 285    through something we don't know how to stabilize.  */
 286 extern tree maybe_stabilize_reference (tree ref, bool force, bool *success);
 287
 288 /* Highest number in the front-end node table.  */
 289 extern int max_gnat_nodes;
 290
 291 /* If nonzero, pretend we are allocating at global level.  */
 292 extern int force_global;
 293
 294 /* Standard data type sizes.  Most of these are not used.  */
 295
 296 #ifndef CHAR_TYPE_SIZE
 297 #define CHAR_TYPE_SIZE BITS_PER_UNIT
 298 #endif
 299
 300 #ifndef SHORT_TYPE_SIZE
 301 #define SHORT_TYPE_SIZE (BITS_PER_UNIT * MIN ((UNITS_PER_WORD + 1) / 2, 2))
 302 #endif
 303
 304 #ifndef INT_TYPE_SIZE
 305 #define INT_TYPE_SIZE BITS_PER_WORD
 306 #endif
 307
 308 #ifndef LONG_TYPE_SIZE
 309 #define LONG_TYPE_SIZE BITS_PER_WORD
 310 #endif
 311
 312 #ifndef LONG_LONG_TYPE_SIZE
 313 #define LONG_LONG_TYPE_SIZE (BITS_PER_WORD * 2)
 314 #endif
 315
 316 #ifndef FLOAT_TYPE_SIZE
 317 #define FLOAT_TYPE_SIZE BITS_PER_WORD
 318 #endif
 319
 320 #ifndef DOUBLE_TYPE_SIZE
 321 #define DOUBLE_TYPE_SIZE (BITS_PER_WORD * 2)
 322 #endif
 323
 324 #ifndef LONG_DOUBLE_TYPE_SIZE
 325 #define LONG_DOUBLE_TYPE_SIZE (BITS_PER_WORD * 2)
 326 #endif
 327
 328 /* The choice of SIZE_TYPE here is very problematic.  We need a signed
 329    type whose bit width is Pmode.  Assume "long" is such a type here.  */
 330 #undef SIZE_TYPE
 331 #define SIZE_TYPE "long int"
 332 \f
 333 /* Data structures used to represent attributes.  */
 334
 335 enum attr_type
 336 {
 337   ATTR_MACHINE_ATTRIBUTE,
 338   ATTR_LINK_ALIAS,
 339   ATTR_LINK_SECTION,
 340   ATTR_LINK_CONSTRUCTOR,
 341   ATTR_LINK_DESTRUCTOR,
 342   ATTR_WEAK_EXTERNAL
 343 };
 344
 345 struct attrib
 346 {
 347   struct attrib *next;
 348   enum attr_type type;
 349   tree name;
 350   tree args;
 351   Node_Id error_point;
 352 };
 353
 354 /* Table of machine-independent internal attributes.  */
 355 extern const struct attribute_spec gnat_internal_attribute_table[];
 356
 357 /* Define the entries in the standard data array.  */
 358 enum standard_datatypes
 359 {
 360 /* Various standard data types and nodes.  */
 361   ADT_longest_float_type,
 362   ADT_void_type_decl,
 363
 364   /* The type of an exception.  */
 365   ADT_except_type,
 366
 367   /* Type declaration node  <==> typedef void *T */
 368   ADT_ptr_void_type,
 369
 370   /* Function type declaration -- void T() */
 371   ADT_void_ftype,
 372
 373   /* Type declaration node  <==> typedef void *T() */
 374   ADT_ptr_void_ftype,
 375
 376   /* A function declaration node for a run-time function for allocating memory.
 377      Ada allocators cause calls to this function to be generated.   */
 378   ADT_malloc_decl,
 379
 380   /* Likewise for freeing memory.  */
 381   ADT_free_decl,
 382
 383   /* Types and decls used by our temporary exception mechanism.  See
 384      init_gigi_decls for details.  */
 385   ADT_jmpbuf_type,
 386   ADT_jmpbuf_ptr_type,
 387   ADT_get_jmpbuf_decl,
 388   ADT_set_jmpbuf_decl,
 389   ADT_get_excptr_decl,
 390   ADT_setjmp_decl,
 391   ADT_longjmp_decl,
 392   ADT_update_setjmp_buf_decl,
 393   ADT_raise_nodefer_decl,
 394   ADT_begin_handler_decl,
 395   ADT_end_handler_decl,
 396   ADT_others_decl,
 397   ADT_all_others_decl,
 398   ADT_LAST};
 399
 400 extern GTY(()) tree gnat_std_decls[(int) ADT_LAST];
 401 extern GTY(()) tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
 402
 403 #define longest_float_type_node gnat_std_decls[(int) ADT_longest_float_type]
 404 #define void_type_decl_node gnat_std_decls[(int) ADT_void_type_decl]
 405 #define except_type_node gnat_std_decls[(int) ADT_except_type]
 406 #define ptr_void_type_node gnat_std_decls[(int) ADT_ptr_void_type]
 407 #define void_ftype gnat_std_decls[(int) ADT_void_ftype]
 408 #define ptr_void_ftype gnat_std_decls[(int) ADT_ptr_void_ftype]
 409 #define malloc_decl gnat_std_decls[(int) ADT_malloc_decl]
 410 #define free_decl gnat_std_decls[(int) ADT_free_decl]
 411 #define jmpbuf_type gnat_std_decls[(int) ADT_jmpbuf_type]
 412 #define jmpbuf_ptr_type gnat_std_decls[(int) ADT_jmpbuf_ptr_type]
 413 #define get_jmpbuf_decl gnat_std_decls[(int) ADT_get_jmpbuf_decl]
 414 #define set_jmpbuf_decl gnat_std_decls[(int) ADT_set_jmpbuf_decl]
 415 #define get_excptr_decl gnat_std_decls[(int) ADT_get_excptr_decl]
 416 #define setjmp_decl gnat_std_decls[(int) ADT_setjmp_decl]
 417 #define longjmp_decl gnat_std_decls[(int) ADT_longjmp_decl]
 418 #define update_setjmp_buf_decl gnat_std_decls[(int) ADT_update_setjmp_buf_decl]
 419 #define raise_nodefer_decl gnat_std_decls[(int) ADT_raise_nodefer_decl]
 420 #define begin_handler_decl gnat_std_decls[(int) ADT_begin_handler_decl]
 421 #define others_decl gnat_std_decls[(int) ADT_others_decl]
 422 #define all_others_decl gnat_std_decls[(int) ADT_all_others_decl]
 423 #define end_handler_decl gnat_std_decls[(int) ADT_end_handler_decl]
 424
 425 /* Routines expected by the gcc back-end. They must have exactly the same
 426    prototype and names as below.  */
 427
 428 /* Returns nonzero if we are currently in the global binding level.  */
 429 extern int global_bindings_p (void);
 430
 431 /* Enter and exit a new binding level. */
 432 extern void gnat_pushlevel (void);
 433 extern void gnat_poplevel (void);
 434
 435 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
 436    and point FNDECL to this BLOCK.  */
 437 extern void set_current_block_context (tree fndecl);
 438
 439 /* Set the jmpbuf_decl for the current binding level to DECL.  */
 440 extern void set_block_jmpbuf_decl (tree decl);
 441
 442 /* Get the setjmp_decl, if any, for the current binding level.  */
 443 extern tree get_block_jmpbuf_decl (void);
 444
 445 /* Insert BLOCK at the end of the list of subblocks of the
 446    current binding level.  This is used when a BIND_EXPR is expanded,
 447    to handle the BLOCK node inside the BIND_EXPR.  */
 448 extern void insert_block (tree block);
 449
 450 /* Records a ..._DECL node DECL as belonging to the current lexical scope
 451    and uses GNAT_NODE for location information.  */
 452 extern void gnat_pushdecl (tree decl, Node_Id gnat_node);
 453
 454 extern void gnat_init_decl_processing (void);
 455 extern void init_gigi_decls (tree long_long_float_type, tree exception_type);
 456 extern void gnat_init_gcc_eh (void);
 457
 458 /* Return an integer type with the number of bits of precision given by
 459    PRECISION.  UNSIGNEDP is nonzero if the type is unsigned; otherwise
 460    it is a signed type.  */
 461 extern tree gnat_type_for_size (unsigned precision, int unsignedp);
 462
 463 /* Return a data type that has machine mode MODE.  UNSIGNEDP selects
 464    an unsigned type; otherwise a signed type is returned.  */
 465 extern tree gnat_type_for_mode (enum machine_mode mode, int unsignedp);
 466
 467 /* Emit debug info for all global variable declarations.  */
 468 extern void gnat_write_global_declarations (void);
 469
 470 /* Return the unsigned version of a TYPE_NODE, a scalar type.  */
 471 extern tree gnat_unsigned_type (tree type_node);
 472
 473 /* Return the signed version of a TYPE_NODE, a scalar type.  */
 474 extern tree gnat_signed_type (tree type_node);
 475
 476 /* Create an expression whose value is that of EXPR,
 477    converted to type TYPE.  The TREE_TYPE of the value
 478    is always TYPE.  This function implements all reasonable
 479    conversions; callers should filter out those that are
 480    not permitted by the language being compiled.  */
 481 extern tree convert (tree type, tree expr);
 482
 483 /* Routines created solely for the tree translator's sake. Their prototypes
 484    can be changed as desired.  */
 485
 486 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
 487    GNU_DECL is the GCC tree which is to be associated with
 488    GNAT_ENTITY. Such gnu tree node is always an ..._DECL node.
 489    If NO_CHECK is nonzero, the latter check is suppressed.
 490    If GNU_DECL is zero, a previous association is to be reset.  */
 491 extern void save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl,
 492                            bool no_check);
 493
 494 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
 495    Return the ..._DECL node that was associated with it.  If there is no tree
 496    node associated with GNAT_ENTITY, abort.  */
 497 extern tree get_gnu_tree (Entity_Id gnat_entity);
 498
 499 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY.  */
 500 extern bool present_gnu_tree (Entity_Id gnat_entity);
 501
 502 /* Initialize tables for above routines.  */
 503 extern void init_gnat_to_gnu (void);
 504
 505 /* Given a record type RECORD_TYPE and a chain of FIELD_DECL nodes FIELDLIST,
 506    finish constructing the record or union type.  If REP_LEVEL is zero, this
 507    record has no representation clause and so will be entirely laid out here.
 508    If REP_LEVEL is one, this record has a representation clause and has been
 509    laid out already; only set the sizes and alignment.  If REP_LEVEL is two,
 510    this record is derived from a parent record and thus inherits its layout;
 511    only make a pass on the fields to finalize them.  If DO_NOT_FINALIZE is
 512    true, the record type is expected to be modified afterwards so it will
 513    not be sent to the back-end for finalization.  */
 514 extern void finish_record_type (tree record_type, tree fieldlist,
 515                                 int rep_level, bool do_not_finalize);
 516
 517 /* Wrap up compilation of RECORD_TYPE, i.e. most notably output all
 518    the debug information associated with it.  It need not be invoked
 519    directly in most cases since finish_record_type takes care of doing
 520    so, unless explicitly requested not to through DO_NOT_FINALIZE.  */
 521 extern void rest_of_record_type_compilation (tree record_type);
 522
 523 /* Returns a FUNCTION_TYPE node. RETURN_TYPE is the type returned by the
 524    subprogram. If it is void_type_node, then we are dealing with a procedure,
 525    otherwise we are dealing with a function. PARAM_DECL_LIST is a list of
 526    PARM_DECL nodes that are the subprogram arguments.  CICO_LIST is the
 527    copy-in/copy-out list to be stored into TYPE_CI_CO_LIST.
 528    RETURNS_UNCONSTRAINED is true if the function returns an unconstrained
 529    object.  RETURNS_BY_REF is true if the function returns by reference.
 530    RETURNS_WITH_DSP is true if the function is to return with a
 531    depressed stack pointer.  RETURNS_BY_TARGET_PTR is true if the function
 532    is to be passed (as its first parameter) the address of the place to copy
 533    its result.  */
 534 extern tree create_subprog_type (tree return_type, tree param_decl_list,
 535                                  tree cico_list, bool returns_unconstrained,
 536                                  bool returns_by_ref, bool returns_with_dsp,
 537                                  bool returns_by_target_ptr);
 538
 539 /* Return a copy of TYPE, but safe to modify in any way.  */
 540 extern tree copy_type (tree type);
 541
 542 /* Return an INTEGER_TYPE of SIZETYPE with range MIN to MAX and whose
 543    TYPE_INDEX_TYPE is INDEX.  GNAT_NODE is used for the position of
 544    the decl.  */
 545 extern tree create_index_type (tree min, tree max, tree index,
 546                                Node_Id gnat_node);
 547
 548 /* Return a TYPE_DECL node. TYPE_NAME gives the name of the type (a character
 549    string) and TYPE is a ..._TYPE node giving its data type.
 550    ARTIFICIAL_P is true if this is a declaration that was generated
 551    by the compiler.  DEBUG_INFO_P is true if we need to write debugging
 552    information about this type.  GNAT_NODE is used for the position of
 553    the decl.  */
 554 extern tree create_type_decl (tree type_name, tree type,
 555                               struct attrib *attr_list,
 556                               bool artificial_p, bool debug_info_p,
 557                               Node_Id gnat_node);
 558
 559 /* Returns a GCC VAR_DECL or CONST_DECL node.
 560
 561    VAR_NAME gives the name of the variable.  ASM_NAME is its assembler name
 562    (if provided).  TYPE is its data type (a GCC ..._TYPE node).  VAR_INIT is
 563    the GCC tree for an optional initial expression; NULL_TREE if none.
 564
 565    CONST_FLAG is true if this variable is constant.
 566
 567    PUBLIC_FLAG is true if this definition is to be made visible outside of
 568    the current compilation unit. This flag should be set when processing the
 569    variable definitions in a package specification.  EXTERN_FLAG is nonzero
 570    when processing an external variable declaration (as opposed to a
 571    definition: no storage is to be allocated for the variable here).
 572
 573    STATIC_FLAG is only relevant when not at top level.  In that case
 574    it indicates whether to always allocate storage to the variable.
 575
 576    GNAT_NODE is used for the position of the decl.  */
 577 extern tree create_var_decl (tree var_name, tree asm_name, tree type,
 578                              tree var_init, bool const_flag,
 579                              bool public_flag, bool extern_flag,
 580                              bool static_flag,
 581                              struct attrib *attr_list, Node_Id gnat_node);
 582
 583 /* Similar to create_var_decl, forcing the creation of a VAR_DECL node.  */
 584 extern tree create_true_var_decl (tree var_name, tree asm_name, tree type,
 585                                   tree var_init, bool const_flag,
 586                                   bool public_flag, bool extern_flag,
 587                                   bool static_flag,
 588                                   struct attrib *attr_list, Node_Id gnat_node);
 589
 590 /* Given a DECL and ATTR_LIST, apply the listed attributes.  */
 591 extern void process_attributes (tree decl, struct attrib *attr_list);
 592
 593 /* Record a global renaming pointer.  */
 594 void record_global_renaming_pointer (tree);
 595
 596 /* Invalidate the global renaming pointers.   */
 597 void invalidate_global_renaming_pointers (void);
 598
 599 /* Returns a FIELD_DECL node. FIELD_NAME the field name, FIELD_TYPE is its
 600    type, and RECORD_TYPE is the type of the parent.  PACKED is nonzero if
 601    this field is in a record type with a "pragma pack".  If SIZE is nonzero
 602    it is the specified size for this field.  If POS is nonzero, it is the bit
 603    position.  If ADDRESSABLE is nonzero, it means we are allowed to take
 604    the address of this field for aliasing purposes.  */
 605 extern tree create_field_decl (tree field_name, tree field_type,
 606                                tree record_type, int packed, tree size,
 607                                tree pos, int addressable);
 608
 609 /* Returns a PARM_DECL node. PARAM_NAME is the name of the parameter,
 610    PARAM_TYPE is its type.  READONLY is true if the parameter is
 611    readonly (either an In parameter or an address of a pass-by-ref
 612    parameter). */
 613 extern tree create_param_decl (tree param_name, tree param_type,
 614                                bool readonly);
 615
 616 /* Returns a FUNCTION_DECL node.  SUBPROG_NAME is the name of the subprogram,
 617    ASM_NAME is its assembler name, SUBPROG_TYPE is its type (a FUNCTION_TYPE
 618    node), PARAM_DECL_LIST is the list of the subprogram arguments (a list of
 619    PARM_DECL nodes chained through the TREE_CHAIN field).
 620
 621    INLINE_FLAG, PUBLIC_FLAG, EXTERN_FLAG, and ATTR_LIST are used to set the
 622    appropriate fields in the FUNCTION_DECL.  GNAT_NODE gives the location.  */
 623 extern tree create_subprog_decl (tree subprog_name, tree asm_name,
 624                                  tree subprog_type, tree param_decl_list,
 625                                  bool inlinee_flag, bool public_flag,
 626                                  bool extern_flag,
 627                                  struct attrib *attr_list, Node_Id gnat_node);
 628
 629 /* Returns a LABEL_DECL node for LABEL_NAME.  */
 630 extern tree create_label_decl (tree label_name);
 631
 632 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
 633    body. This routine needs to be invoked before processing the declarations
 634    appearing in the subprogram.  */
 635 extern void begin_subprog_body (tree subprog_decl);
 636
 637 /* Finish the definition of the current subprogram and compile it all the way
 638    to assembler language output.  BODY is the tree corresponding to
 639    the subprogram.  */
 640 extern void end_subprog_body (tree body);
 641
 642 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
 643    EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
 644    Return a constructor for the template.  */
 645 extern tree build_template (tree template_type, tree array_type, tree expr);
 646
 647 /* Build a VMS descriptor from a Mechanism_Type, which must specify
 648    a descriptor type, and the GCC type of an object.  Each FIELD_DECL
 649    in the type contains in its DECL_INITIAL the expression to use when
 650    a constructor is made for the type.  GNAT_ENTITY is a gnat node used
 651    to print out an error message if the mechanism cannot be applied to
 652    an object of that type and also for the name.  */
 653 extern tree build_vms_descriptor (tree type, Mechanism_Type mech,
 654                                   Entity_Id gnat_entity);
 655
 656 /* Build a stub for the subprogram specified by the GCC tree GNU_SUBPROG
 657    and the GNAT node GNAT_SUBPROG.  */
 658 extern void build_function_stub (tree gnu_subprog, Entity_Id gnat_subprog);
 659
 660 /* Build a type to be used to represent an aliased object whose nominal
 661    type is an unconstrained array.  This consists of a RECORD_TYPE containing
 662    a field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an
 663    ARRAY_TYPE.  If ARRAY_TYPE is that of the unconstrained array, this
 664    is used to represent an arbitrary unconstrained object.  Use NAME
 665    as the name of the record.  */
 666 extern tree build_unc_object_type (tree template_type, tree object_type,
 667                                    tree name);
 668
 669 /* Same as build_unc_object_type, but taking a thin or fat pointer type
 670    instead of the template type. */
 671 extern tree build_unc_object_type_from_ptr (tree thin_fat_ptr_type,
 672                                             tree object_type, tree name);
 673
 674 /* Shift the component offsets within an unconstrained object TYPE to make it
 675    suitable for use as a designated type for thin pointers.  */
 676 extern void shift_unc_components_for_thin_pointers (tree type);
 677
 678 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.  In
 679    the normal case this is just two adjustments, but we have more to do
 680    if NEW is an UNCONSTRAINED_ARRAY_TYPE.  */
 681 extern void update_pointer_to (tree old_type, tree new_type);
 682
 683 /* EXP is an expression for the size of an object.  If this size contains
 684    discriminant references, replace them with the maximum (if MAX_P) or
 685    minimum (if !MAX_P) possible value of the discriminant.  */
 686 extern tree max_size (tree exp, bool max_p);
 687
 688 /* Remove all conversions that are done in EXP.  This includes converting
 689    from a padded type or to a left-justified modular type.  If TRUE_ADDRESS
 690    is true, always return the address of the containing object even if
 691    the address is not bit-aligned.  */
 692 extern tree remove_conversions (tree exp, bool true_address);
 693
 694 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
 695    refers to the underlying array.  If its type has TYPE_CONTAINS_TEMPLATE_P,
 696    likewise return an expression pointing to the underlying array.  */
 697 extern tree maybe_unconstrained_array (tree exp);
 698
 699 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
 700    If NOTRUNC_P is true, truncation operations should be suppressed.  */
 701 extern tree unchecked_convert (tree type, tree expr, bool notrunc_p);
 702
 703 /* Return the appropriate GCC tree code for the specified GNAT type,
 704    the latter being a record type as predicated by Is_Record_Type.  */
 705 extern enum tree_code tree_code_for_record_type (Entity_Id);
 706
 707 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
 708    component of an aggregate type.  */
 709 extern bool type_for_nonaliased_component_p (tree);
 710
 711 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 712    operation.
 713
 714    This preparation consists of taking the ordinary
 715    representation of an expression EXPR and producing a valid tree
 716    boolean expression describing whether EXPR is nonzero.  We could
 717    simply always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 718    but we optimize comparisons, &&, ||, and !.
 719
 720    The resulting type should always be the same as the input type.
 721    This function is simpler than the corresponding C version since
 722    the only possible operands will be things of Boolean type.  */
 723 extern tree gnat_truthvalue_conversion (tree expr);
 724
 725 /* Return the base type of TYPE.  */
 726 extern tree get_base_type (tree type);
 727
 728 /* EXP is a GCC tree representing an address.  See if we can find how
 729    strictly the object at that address is aligned.   Return that alignment
 730    strictly the object at that address is aligned.   Return that alignment
 731    in bits.  If we don't know anything about the alignment, return 0.  */
 732 extern unsigned int known_alignment (tree exp);
 733
 734 /* Return true if VALUE is a multiple of FACTOR. FACTOR must be a power
 735    of 2. */
 736 extern bool value_factor_p (tree value, HOST_WIDE_INT factor);
 737
 738 /* Make a binary operation of kind OP_CODE.  RESULT_TYPE is the type
 739    desired for the result.  Usually the operation is to be performed
 740    in that type.  For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
 741    in which case the type to be used will be derived from the operands.  */
 742 extern tree build_binary_op (enum tree_code op_code, tree retult_type,
 743                              tree left_operand, tree right_operand);
 744
 745 /* Similar, but make unary operation.   */
 746 extern tree build_unary_op (enum tree_code op_code, tree result_type,
 747                             tree operand);
 748
 749 /* Similar, but for COND_EXPR.  */
 750 extern tree build_cond_expr (tree result_type, tree condition_operand,
 751                              tree true_operand, tree false_operand);
 752
 753 /* Similar, but for RETURN_EXPR.  */
 754 extern tree build_return_expr (tree result_decl, tree ret_val);
 755
 756 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG.  Return
 757    the CALL_EXPR.  */
 758 extern tree build_call_1_expr (tree fundecl, tree arg);
 759
 760 /* Build a CALL_EXPR to call FUNDECL with two argument, ARG1 & ARG2.  Return
 761    the CALL_EXPR.  */
 762 extern tree build_call_2_expr (tree fundecl, tree arg1, tree arg2);
 763
 764 /* Likewise to call FUNDECL with no arguments.  */
 765 extern tree build_call_0_expr (tree fundecl);
 766
 767 /* Call a function that raises an exception and pass the line number and file
 768    name, if requested.  MSG says which exception function to call.
 769
 770    GNAT_NODE is the gnat node conveying the source location for which the
 771    error should be signaled, or Empty in which case the error is signaled on
 772    the current ref_file_name/input_line.
 773
 774    KIND says which kind of exception this is for
 775     (N_Raise_{Constraint,Storage,Program}_Error).  */
 776 extern tree build_call_raise (int msg, Node_Id gnat_node, char kind);
 777
 778 /* Return a CONSTRUCTOR of TYPE whose list is LIST.  This is not the
 779    same as build_constructor in the language-independent tree.c.  */
 780 extern tree gnat_build_constructor (tree type, tree list);
 781
 782 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
 783    an IDENTIFIER_NODE giving the name of the field, FIELD, a FIELD_DECL,
 784    for the field, or both.  Don't fold the result if NO_FOLD_P.  */
 785 extern tree build_component_ref (tree record_variable, tree component,
 786                                  tree field, bool no_fold_p);
 787
 788 /* Build a GCC tree to call an allocation or deallocation function.
 789    If GNU_OBJ is nonzero, it is an object to deallocate.  Otherwise,
 790    genrate an allocator.
 791
 792    GNU_SIZE is the size of the object and ALIGN is the alignment.
 793    GNAT_PROC, if present is a procedure to call and GNAT_POOL is the
 794    storage pool to use.  If not preset, malloc and free will be used.  */
 795 extern tree build_call_alloc_dealloc (tree gnu_obj, tree gnu_size,
 796                                       unsigned align, Entity_Id gnat_proc,
 797                                       Entity_Id gnat_pool, Node_Id gnat_node);
 798
 799 /* Build a GCC tree to correspond to allocating an object of TYPE whose
 800    initial value if INIT, if INIT is nonzero.  Convert the expression to
 801    RESULT_TYPE, which must be some type of pointer.  Return the tree.
 802    GNAT_PROC and GNAT_POOL optionally give the procedure to call and
 803    the storage pool to use.  GNAT_NODE is used to provide an error
 804    location for restriction violations messages.  If IGNORE_INIT_TYPE is
 805    true, ignore the type of INIT for the purpose of determining the size;
 806    this will cause the maximum size to be allocated if TYPE is of
 807    self-referential size.  */
 808 extern tree build_allocator (tree type, tree init, tree result_type,
 809                              Entity_Id gnat_proc, Entity_Id gnat_pool,
 810                              Node_Id gnat_node, bool);
 811
 812 /* Fill in a VMS descriptor for EXPR and return a constructor for it.
 813    GNAT_FORMAL is how we find the descriptor record.  */
 814
 815 extern tree fill_vms_descriptor (tree expr, Entity_Id gnat_formal);
 816
 817 /* Indicate that we need to make the address of EXPR_NODE and it therefore
 818    should not be allocated in a register.  Return true if successful.  */
 819 extern bool gnat_mark_addressable (tree expr_node);
 820
 821 /* Implementation of the builtin_function langhook.  */
 822 extern tree gnat_builtin_function (tree decl);
 823
 824 /* Search the chain of currently reachable declarations for a builtin
 825    FUNCTION_DECL node corresponding to function NAME (an IDENTIFIER_NODE).
 826    Return the first node found, if any, or NULL_TREE otherwise.  */
 827 extern tree builtin_decl_for (tree name ATTRIBUTE_UNUSED);
 828
 829 /* This function is called by the front end to enumerate all the supported
 830    modes for the machine.  We pass a function which is called back with
 831    the following integer parameters:
 832
 833    FLOAT_P      nonzero if this represents a floating-point mode
 834    COMPLEX_P    nonzero is this represents a complex mode
 835    COUNT        count of number of items, nonzero for vector mode
 836    PRECISION    number of bits in data representation
 837    MANTISSA     number of bits in mantissa, if FP and known, else zero.
 838    SIZE         number of bits used to store data
 839    ALIGN        number of bits to which mode is aligned.  */
 840 extern void enumerate_modes (void (*f) (int, int, int, int, int, int,
 841                                         unsigned int));
 842
 843 /* These are temporary function to deal with recent GCC changes related to
 844    FP type sizes and precisions.  */
 845 extern int fp_prec_to_size (int prec);
 846 extern int fp_size_to_prec (int size);
 847
 848 /* These functions return the basic data type sizes and related parameters
 849    about the target machine.  */
 850
 851 extern Pos get_target_bits_per_unit (void);
 852 extern Pos get_target_bits_per_word (void);
 853 extern Pos get_target_char_size (void);
 854 extern Pos get_target_wchar_t_size (void);
 855 extern Pos get_target_short_size (void);
 856 extern Pos get_target_int_size (void);
 857 extern Pos get_target_long_size (void);
 858 extern Pos get_target_long_long_size (void);
 859 extern Pos get_target_float_size (void);
 860 extern Pos get_target_double_size (void);
 861 extern Pos get_target_long_double_size (void);
 862 extern Pos get_target_pointer_size (void);
 863 extern Pos get_target_maximum_alignment (void);
 864 extern Pos get_target_default_allocator_alignment (void);
 865 extern Pos get_target_maximum_default_alignment (void);
 866 extern Pos get_target_maximum_allowed_alignment (void);
 867 extern Nat get_float_words_be (void);
 868 extern Nat get_words_be (void);
 869 extern Nat get_bytes_be (void);
 870 extern Nat get_bits_be (void);
 871 extern Nat get_strict_alignment (void);