summaryrefslogtreecommitdiff
path: root/gcc/ada/types.ads
blob: ee2966c86a75fe49b6740be44923fb28e2e035a8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                                T Y P E S                                 --
--                                                                          --
--                                 S p e c                                  --
--                                                                          --
--          Copyright (C) 1992-2010, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
--                                                                          --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception,   --
-- version 3.1, as published by the Free Software Foundation.               --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

--  This package contains host independent type definitions which are used
--  in more than one unit in the compiler. They are gathered here for easy
--  reference, although in some cases the full description is found in the
--  relevant module which implements the definition. The main reason that they
--  are not in their "natural" specs is that this would cause a lot of inter-
--  spec dependencies, and in particular some awkward circular dependencies
--  would have to be dealt with.

--  WARNING: There is a C version of this package. Any changes to this source
--  file must be properly reflected in the C header file types.h declarations.

--  Note: the declarations in this package reflect an expectation that the host
--  machine has an efficient integer base type with a range at least 32 bits
--  2s-complement. If there are any machines for which this is not a correct
--  assumption, a significant number of changes will be required!

with System;
with Unchecked_Conversion;
with Unchecked_Deallocation;

package Types is
   pragma Preelaborate;

   -------------------------------
   -- General Use Integer Types --
   -------------------------------

   type Int is range -2 ** 31 .. +2 ** 31 - 1;
   --  Signed 32-bit integer

   subtype Nat is Int range 0 .. Int'Last;
   --  Non-negative Int values

   subtype Pos is Int range 1 .. Int'Last;
   --  Positive Int values

   type Word is mod 2 ** 32;
   --  Unsigned 32-bit integer

   type Short is range -32768 .. +32767;
   for Short'Size use 16;
   --  16-bit signed integer

   type Byte is mod 2 ** 8;
   for Byte'Size use 8;
   --  8-bit unsigned integer

   type size_t is mod 2 ** Standard'Address_Size;
   --  Memory size value, for use in calls to C routines

   --------------------------------------
   -- 8-Bit Character and String Types --
   --------------------------------------

   --  We use Standard.Character and Standard.String freely, since we are
   --  compiling ourselves, and we properly implement the required 8-bit
   --  character code as required in Ada 95. This section defines a few
   --  general use constants and subtypes.

   EOF : constant Character := ASCII.SUB;
   --  The character SUB (16#1A#) is used in DOS and other systems derived
   --  from DOS (XP, NT etc) to signal the end of a text file. Internally
   --  all source files are ended by an EOF character, even on Unix systems.
   --  An EOF character acts as the end of file only as the last character
   --  of a source buffer, in any other position, it is treated as a blank
   --  if it appears between tokens, and as an illegal character otherwise.
   --  This makes life easier dealing with files that originated from DOS,
   --  including concatenated files with interspersed EOF characters.

   subtype Graphic_Character is Character range ' ' .. '~';
   --  Graphic characters, as defined in ARM

   subtype Line_Terminator is Character range ASCII.LF .. ASCII.CR;
   --  Line terminator characters (LF, VT, FF, CR)
   --
   --  This definition is dubious now that we have two more wide character
   --  sequences that constitute a line terminator. Every reference to this
   --  subtype needs checking to make sure the wide character case is handled
   --  appropriately. ???

   subtype Upper_Half_Character is
     Character range Character'Val (16#80#) .. Character'Val (16#FF#);
   --  Characters with the upper bit set

   type Character_Ptr is access all Character;
   type String_Ptr    is access all String;
   --  Standard character and string pointers

   procedure Free is new Unchecked_Deallocation (String, String_Ptr);
   --  Procedure for freeing dynamically allocated String values

   subtype Big_String is String (Positive);
   type Big_String_Ptr is access all Big_String;
   --  Virtual type for handling imported big strings. Note that we should
   --  never have any allocators for this type, but we don't give a storage
   --  size of zero, since there are legitimate deallocations going on.

   function To_Big_String_Ptr is
     new Unchecked_Conversion (System.Address, Big_String_Ptr);
   --  Used to obtain Big_String_Ptr values from external addresses

   subtype Word_Hex_String is String (1 .. 8);
   --  Type used to represent Word value as 8 hex digits, with lower case
   --  letters for the alphabetic cases.

   function Get_Hex_String (W : Word) return Word_Hex_String;
   --  Convert word value to 8-character hex string

   -----------------------------------------
   -- Types Used for Text Buffer Handling --
   -----------------------------------------

   --  We can not use type String for text buffers, since we must use the
   --  standard 32-bit integer as an index value, since we count on all index
   --  values being the same size.

   type Text_Ptr is new Int;
   --  Type used for subscripts in text buffer

   type Text_Buffer is array (Text_Ptr range <>) of Character;
   --  Text buffer used to hold source file or library information file

   type Text_Buffer_Ptr is access all Text_Buffer;
   --  Text buffers for input files are allocated dynamically and this type
   --  is used to reference these text buffers.

   procedure Free is new Unchecked_Deallocation (Text_Buffer, Text_Buffer_Ptr);
   --  Procedure for freeing dynamically allocated text buffers

   ------------------------------------------
   -- Types Used for Source Input Handling --
   ------------------------------------------

   type Logical_Line_Number is range 0 .. Int'Last;
   for Logical_Line_Number'Size use 32;
   --  Line number type, used for storing logical line numbers (i.e. line
   --  numbers that include effects of any Source_Reference pragmas in the
   --  source file). The value zero indicates a line containing a source
   --  reference pragma.

   No_Line_Number : constant Logical_Line_Number := 0;
   --  Special value used to indicate no line number

   type Physical_Line_Number is range 1 .. Int'Last;
   for Physical_Line_Number'Size use 32;
   --  Line number type, used for storing physical line numbers (i.e. line
   --  numbers in the physical file being compiled, unaffected by the presence
   --  of source reference pragmas.

   type Column_Number is range 0 .. 32767;
   for Column_Number'Size use 16;
   --  Column number (assume that 2**15 - 1 is large enough). The range for
   --  this type is used to compute Hostparm.Max_Line_Length. See also the
   --  processing for -gnatyM in Stylesw).

   No_Column_Number : constant Column_Number := 0;
   --  Special value used to indicate no column number

   subtype Source_Buffer is Text_Buffer;
   --  Type used to store text of a source file . The buffer for the main
   --  source (the source specified on the command line) has a lower bound
   --  starting at zero. Subsequent subsidiary sources have lower bounds
   --  which are one greater than the previous upper bound.

   subtype Big_Source_Buffer is Text_Buffer (0 .. Text_Ptr'Last);
   --  This is a virtual type used as the designated type of the access type
   --  Source_Buffer_Ptr, see Osint.Read_Source_File for details.

   type Source_Buffer_Ptr is access all Big_Source_Buffer;
   --  Pointer to source buffer. We use virtual origin addressing for source
   --  buffers, with thin pointers. The pointer points to a virtual instance
   --  of type Big_Source_Buffer, where the actual type is in fact of type
   --  Source_Buffer. The address is adjusted so that the virtual origin
   --  addressing works correctly. See Osint.Read_Source_Buffer for further
   --  details. Again, as for Big_String_Ptr, we should never allocate using
   --  this type, but we don't give a storage size clause of zero, since we
   --  may end up doing deallocations of instances allocated manually.

   subtype Source_Ptr is Text_Ptr;
   --  Type used to represent a source location, which is a subscript of a
   --  character in the source buffer. As noted above, different source buffers
   --  have different ranges, so it is possible to tell from a Source_Ptr value
   --  which source it refers to. Note that negative numbers are allowed to
   --  accommodate the following special values.

   No_Location : constant Source_Ptr := -1;
   --  Value used to indicate no source position set in a node. A test for a
   --  Source_Ptr value being > No_Location is the approved way to test for a
   --  standard value that does not include No_Location or any of the following
   --  special definitions. One important use of No_Location is to label
   --  generated nodes that we don't want the debugger to see in normal mode
   --  (very often we conditionalize so that we set No_Location in normal mode
   --  and the corresponding source line in -gnatD mode).

   Standard_Location : constant Source_Ptr := -2;
   --  Used for all nodes in the representation of package Standard other than
   --  nodes representing the contents of Standard.ASCII. Note that testing for
   --  a value being <= Standard_Location tests for both Standard_Location and
   --  for Standard_ASCII_Location.

   Standard_ASCII_Location : constant Source_Ptr := -3;
   --  Used for all nodes in the presentation of package Standard.ASCII

   System_Location : constant Source_Ptr := -4;
   --  Used to identify locations of pragmas scanned by Targparm, where we know
   --  the location is in System, but we don't know exactly what line.

   First_Source_Ptr : constant Source_Ptr := 0;
   --  Starting source pointer index value for first source program

   -------------------------------------
   -- Range Definitions for Tree Data --
   -------------------------------------

   --  The tree has fields that can hold any of the following types:

   --    Pointers to other tree nodes (type Node_Id)
   --    List pointers (type List_Id)
   --    Element list pointers (type Elist_Id)
   --    Names (type Name_Id)
   --    Strings (type String_Id)
   --    Universal integers (type Uint)
   --    Universal reals (type Ureal)

   --  In most contexts, the strongly typed interface determines which of these
   --  types is present. However, there are some situations (involving untyped
   --  traversals of the tree), where it is convenient to be easily able to
   --  distinguish these values. The underlying representation in all cases is
   --  an integer type Union_Id, and we ensure that the range of the various
   --  possible values for each of the above types is disjoint so that this
   --  distinction is possible.

   type Union_Id is new Int;
   --  The type in the tree for a union of possible ID values

   --  Note: it is also helpful for debugging purposes to make these ranges
   --  distinct. If a bug leads to misidentification of a value, then it will
   --  typically result in an out of range value and a Constraint_Error.

   List_Low_Bound : constant := -100_000_000;
   --  The List_Id values are subscripts into an array of list headers which
   --  has List_Low_Bound as its lower bound. This value is chosen so that all
   --  List_Id values are negative, and the value zero is in the range of both
   --  List_Id and Node_Id values (see further description below).

   List_High_Bound : constant := 0;
   --  Maximum List_Id subscript value. This allows up to 100 million list Id
   --  values, which is in practice infinite, and there is no need to check the
   --  range. The range overlaps the node range by one element (with value
   --  zero), which is used both for the Empty node, and for indicating no
   --  list. The fact that the same value is used is convenient because it
   --  means that the default value of Empty applies to both nodes and lists,
   --  and also is more efficient to test for.

   Node_Low_Bound : constant := 0;
   --  The tree Id values start at zero, because we use zero for Empty (to
   --  allow a zero test for Empty). Actual tree node subscripts start at 0
   --  since Empty is a legitimate node value.

   Node_High_Bound : constant := 099_999_999;
   --  Maximum number of nodes that can be allocated is 100 million, which
   --  is in practice infinite, and there is no need to check the range.

   Elist_Low_Bound : constant := 100_000_000;
   --  The Elist_Id values are subscripts into an array of elist headers which
   --  has Elist_Low_Bound as its lower bound.

   Elist_High_Bound : constant := 199_999_999;
   --  Maximum Elist_Id subscript value. This allows up to 100 million Elists,
   --  which is in practice infinite and there is no need to check the range.

   Elmt_Low_Bound : constant := 200_000_000;
   --  Low bound of element Id values. The use of these values is internal to
   --  the Elists package, but the definition of the range is included here
   --  since it must be disjoint from other Id values. The Elmt_Id values are
   --  subscripts into an array of list elements which has this as lower bound.

   Elmt_High_Bound : constant := 299_999_999;
   --  Upper bound of Elmt_Id values. This allows up to 100 million element
   --  list members, which is in practice infinite (no range check needed).

   Names_Low_Bound : constant := 300_000_000;
   --  Low bound for name Id values

   Names_High_Bound : constant := 399_999_999;
   --  Maximum number of names that can be allocated is 100 million, which is
   --  in practice infinite and there is no need to check the range.

   Strings_Low_Bound : constant := 400_000_000;
   --  Low bound for string Id values

   Strings_High_Bound : constant := 499_999_999;
   --  Maximum number of strings that can be allocated is 100 million, which
   --  is in practice infinite and there is no need to check the range.

   Ureal_Low_Bound : constant := 500_000_000;
   --  Low bound for Ureal values

   Ureal_High_Bound : constant := 599_999_999;
   --  Maximum number of Ureal values stored is 100_000_000 which is in
   --  practice infinite so that no check is required.

   Uint_Low_Bound : constant := 600_000_000;
   --  Low bound for Uint values

   Uint_Table_Start : constant := 2_000_000_000;
   --  Location where table entries for universal integers start (see
   --  Uintp spec for details of the representation of Uint values).

   Uint_High_Bound : constant := 2_099_999_999;
   --  The range of Uint values is very large, since a substantial part
   --  of this range is used to store direct values, see Uintp for details.

   --  The following subtype definitions are used to provide convenient names
   --  for membership tests on Int values to see what data type range they
   --  lie in. Such tests appear only in the lowest level packages.

   subtype List_Range      is Union_Id
     range List_Low_Bound    .. List_High_Bound;

   subtype Node_Range      is Union_Id
     range Node_Low_Bound    .. Node_High_Bound;

   subtype Elist_Range     is Union_Id
     range Elist_Low_Bound   .. Elist_High_Bound;

   subtype Elmt_Range      is Union_Id
     range Elmt_Low_Bound    .. Elmt_High_Bound;

   subtype Names_Range     is Union_Id
     range Names_Low_Bound   .. Names_High_Bound;

   subtype Strings_Range   is Union_Id
     range Strings_Low_Bound .. Strings_High_Bound;

   subtype Uint_Range      is Union_Id
     range Uint_Low_Bound    .. Uint_High_Bound;

   subtype Ureal_Range     is Union_Id
     range Ureal_Low_Bound   .. Ureal_High_Bound;

   -----------------------------
   -- Types for Atree Package --
   -----------------------------

   --  Node_Id values are used to identify nodes in the tree. They are
   --  subscripts into the Nodes table declared in package Atree. Note that
   --  the special values Empty and Error are subscripts into this table.
   --  See package Atree for further details.

   type Node_Id is range Node_Low_Bound .. Node_High_Bound;
   --  Type used to identify nodes in the tree

   subtype Entity_Id is Node_Id;
   --  A synonym for node types, used in the Einfo package to refer to nodes
   --  that are entities (i.e. nodes with an Nkind of N_Defining_xxx). All such
   --  nodes are extended nodes and these are the only extended nodes, so that
   --  in practice entity and extended nodes are synonymous.

   subtype Node_Or_Entity_Id is Node_Id;
   --  A synonym for node types, used in cases where a given value may be used
   --  to represent either a node or an entity. We like to minimize such uses
   --  for obvious reasons of logical type consistency, but where such uses
   --  occur, they should be documented by use of this type.

   Empty : constant Node_Id := Node_Low_Bound;
   --  Used to indicate null node. A node is actually allocated with this
   --  Id value, so that Nkind (Empty) = N_Empty. Note that Node_Low_Bound
   --  is zero, so Empty = No_List = zero.

   Empty_List_Or_Node : constant := 0;
   --  This constant is used in situations (e.g. initializing empty fields)
   --  where the value set will be used to represent either an empty node or
   --  a non-existent list, depending on the context.

   Error : constant Node_Id := Node_Low_Bound + 1;
   --  Used to indicate an error in the source program. A node is actually
   --  allocated with this Id value, so that Nkind (Error) = N_Error.

   Empty_Or_Error : constant Node_Id := Error;
   --  Since Empty and Error are the first two Node_Id values, the test for
   --  N <= Empty_Or_Error tests to see if N is Empty or Error. This definition
   --  provides convenient self-documentation for such tests.

   First_Node_Id  : constant Node_Id := Node_Low_Bound;
   --  Subscript of first allocated node. Note that Empty and Error are both
   --  allocated nodes, whose Nkind fields can be accessed without error.

   ------------------------------
   -- Types for Nlists Package --
   ------------------------------

   --  List_Id values are used to identify node lists stored in the tree, so
   --  that each node can be on at most one such list (see package Nlists for
   --  further details). Note that the special value Error_List is a subscript
   --  in this table, but the value No_List is *not* a valid subscript, and any
   --  attempt to apply list operations to No_List will cause a (detected)
   --  error.

   type List_Id is range List_Low_Bound .. List_High_Bound;
   --  Type used to identify a node list

   No_List : constant List_Id := List_High_Bound;
   --  Used to indicate absence of a list. Note that the value is zero, which
   --  is the same as Empty, which is helpful in initializing nodes where a
   --  value of zero can represent either an empty node or an empty list.

   Error_List : constant List_Id := List_Low_Bound;
   --  Used to indicate that there was an error in the source program in a
   --  context which would normally require a list. This node appears to be
   --  an empty list to the list operations (a null list is actually allocated
   --  which has this Id value).

   First_List_Id : constant List_Id := Error_List;
   --  Subscript of first allocated list header

   ------------------------------
   -- Types for Elists Package --
   ------------------------------

   --  Element list Id values are used to identify element lists stored outside
   --  of the tree, allowing nodes to be members of more than one such list
   --  (see package Elists for further details).

   type Elist_Id is range Elist_Low_Bound .. Elist_High_Bound;
   --  Type used to identify an element list (Elist header table subscript)

   No_Elist : constant Elist_Id := Elist_Low_Bound;
   --  Used to indicate absence of an element list. Note that this is not an
   --  actual Elist header, so element list operations on this value are not
   --  valid.

   First_Elist_Id : constant Elist_Id := No_Elist + 1;
   --  Subscript of first allocated Elist header

   --  Element Id values are used to identify individual elements of an element
   --  list (see package Elists for further details).

   type Elmt_Id is range Elmt_Low_Bound .. Elmt_High_Bound;
   --  Type used to identify an element list

   No_Elmt : constant Elmt_Id := Elmt_Low_Bound;
   --  Used to represent empty element

   First_Elmt_Id : constant Elmt_Id := No_Elmt + 1;
   --  Subscript of first allocated Elmt table entry

   -------------------------------
   -- Types for Stringt Package --
   -------------------------------

   --  String_Id values are used to identify entries in the strings table. They
   --  are subscripts into the Strings table defined in package Stringt.

   --  Note that with only a few exceptions, which are clearly documented, the
   --  type String_Id should be regarded as a private type. In particular it is
   --  never appropriate to perform arithmetic operations using this type.
   --  Doesn't this also apply to all other *_Id types???

   type String_Id is range Strings_Low_Bound .. Strings_High_Bound;
   --  Type used to identify entries in the strings table

   No_String : constant String_Id := Strings_Low_Bound;
   --  Used to indicate missing string Id. Note that the value zero is used
   --  to indicate a missing data value for all the Int types in this section.

   First_String_Id : constant String_Id := No_String + 1;
   --  First subscript allocated in string table

   -------------------------
   -- Character Code Type --
   -------------------------

   --  The type Char is used for character data internally in the compiler, but
   --  character codes in the source are represented by the Char_Code type.
   --  Each character literal in the source is interpreted as being one of the
   --  16#7FFF_FFFF# possible Wide_Wide_Character codes, and a unique Integer
   --  value is assigned, corresponding to the UTF-32 value, which also
   --  corresponds to the Pos value in the Wide_Wide_Character type, and also
   --  corresponds to the Pos value in the Wide_Character and Character types
   --  for values that are in appropriate range. String literals are similarly
   --  interpreted as a sequence of such codes.

   type Char_Code_Base is mod 2 ** 32;
   for Char_Code_Base'Size use 32;

   subtype Char_Code is Char_Code_Base range 0 .. 16#7FFF_FFFF#;
   for Char_Code'Value_Size use 32;
   for Char_Code'Object_Size use 32;

   function Get_Char_Code (C : Character) return Char_Code;
   pragma Inline (Get_Char_Code);
   --  Function to obtain internal character code from source character. For
   --  the moment, the internal character code is simply the Pos value of the
   --  input source character, but we provide this interface for possible
   --  later support of alternative character sets.

   function In_Character_Range (C : Char_Code) return Boolean;
   pragma Inline (In_Character_Range);
   --  Determines if the given character code is in range of type Character,
   --  and if so, returns True. If not, returns False.

   function In_Wide_Character_Range (C : Char_Code) return Boolean;
   pragma Inline (In_Wide_Character_Range);
   --  Determines if the given character code is in range of the type
   --  Wide_Character, and if so, returns True. If not, returns False.

   function Get_Character (C : Char_Code) return Character;
   pragma Inline (Get_Character);
   --  For a character C that is in Character range (see above function), this
   --  function returns the corresponding Character value. It is an error to
   --  call Get_Character if C is not in Character range.

   function Get_Wide_Character (C : Char_Code) return Wide_Character;
   --  For a character C that is in Wide_Character range (see above function),
   --  this function returns the corresponding Wide_Character value. It is an
   --  error to call Get_Wide_Character if C is not in Wide_Character range.

   ---------------------------------------
   -- Types used for Library Management --
   ---------------------------------------

   type Unit_Number_Type is new Int;
   --  Unit number. The main source is unit 0, and subsidiary sources have
   --  non-zero numbers starting with 1. Unit numbers are used to index the
   --  Units table in package Lib.

   Main_Unit : constant Unit_Number_Type := 0;
   --  Unit number value for main unit

   No_Unit : constant Unit_Number_Type := -1;
   --  Special value used to signal no unit

   type Source_File_Index is new Int range -1 .. Int'Last;
   --  Type used to index the source file table (see package Sinput)

   Internal_Source_File : constant Source_File_Index :=
                            Source_File_Index'First;
   --  Value used to indicate the buffer for the source-code-like strings
   --  internally created withing the compiler (see package Sinput)

   No_Source_File : constant Source_File_Index := 0;
   --  Value used to indicate no source file present

   -----------------------------------
   -- Representation of Time Stamps --
   -----------------------------------

   --  All compiled units are marked with a time stamp which is derived from
   --  the source file (we assume that the host system has the concept of a
   --  file time stamp which is modified when a file is modified). These
   --  time stamps are used to ensure consistency of the set of units that
   --  constitutes a library. Time stamps are 12 character strings with
   --  with the following format:

   --     YYYYMMDDHHMMSS

   --       YYYY   year
   --       MM     month (2 digits 01-12)
   --       DD     day (2 digits 01-31)
   --       HH     hour (2 digits 00-23)
   --       MM     minutes (2 digits 00-59)
   --       SS     seconds (2 digits 00-59)

   --  In the case of Unix systems (and other systems which keep the time in
   --  GMT), the time stamp is the GMT time of the file, not the local time.
   --  This solves problems in using libraries across networks with clients
   --  spread across multiple time-zones.

   Time_Stamp_Length : constant := 14;
   --  Length of time stamp value

   subtype Time_Stamp_Index is Natural range 1 .. Time_Stamp_Length;
   type Time_Stamp_Type is new String (Time_Stamp_Index);
   --  Type used to represent time stamp

   Empty_Time_Stamp : constant Time_Stamp_Type := (others => ' ');
   --  Value representing an empty or missing time stamp. Looks less than any
   --  real time stamp if two time stamps are compared. Note that although this
   --  is not private, clients should not rely on the exact way in which this
   --  string is represented, and instead should use the subprograms below.

   Dummy_Time_Stamp : constant Time_Stamp_Type := (others => '0');
   --  This is used for dummy time stamp values used in the D lines for
   --  non-existent files, and is intended to be an impossible value.

   function "="  (Left, Right : Time_Stamp_Type) return Boolean;
   function "<=" (Left, Right : Time_Stamp_Type) return Boolean;
   function ">=" (Left, Right : Time_Stamp_Type) return Boolean;
   function "<"  (Left, Right : Time_Stamp_Type) return Boolean;
   function ">"  (Left, Right : Time_Stamp_Type) return Boolean;
   --  Comparison functions on time stamps. Note that two time stamps are
   --  defined as being equal if they have the same day/month/year and the
   --  hour/minutes/seconds values are within 2 seconds of one another. This
   --  deals with rounding effects in library file time stamps caused by
   --  copying operations during installation. We have particularly noticed
   --  that WinNT seems susceptible to such changes.
   --
   --  Note : the Empty_Time_Stamp value looks equal to itself, and less than
   --  any non-empty time stamp value.

   procedure Split_Time_Stamp
     (TS      : Time_Stamp_Type;
      Year    : out Nat;
      Month   : out Nat;
      Day     : out Nat;
      Hour    : out Nat;
      Minutes : out Nat;
      Seconds : out Nat);
   --  Given a time stamp, decompose it into its components

   procedure Make_Time_Stamp
     (Year    : Nat;
      Month   : Nat;
      Day     : Nat;
      Hour    : Nat;
      Minutes : Nat;
      Seconds : Nat;
      TS      : out Time_Stamp_Type);
   --  Given the components of a time stamp, initialize the value

   -----------------------------------------------
   -- Types used for Pragma Suppress Management --
   -----------------------------------------------

   type Check_Id is new Nat;
   --  Type used to represent a check id

   No_Check_Id         : constant := 0;
   --  Check_Id value used to indicate no check

   Access_Check        : constant :=  1;
   Accessibility_Check : constant :=  2;
   Alignment_Check     : constant :=  3;
   Discriminant_Check  : constant :=  4;
   Division_Check      : constant :=  5;
   Elaboration_Check   : constant :=  6;
   Index_Check         : constant :=  7;
   Length_Check        : constant :=  8;
   Overflow_Check      : constant :=  9;
   Range_Check         : constant := 10;
   Storage_Check       : constant := 11;
   Tag_Check           : constant := 12;
   Validity_Check      : constant := 13;
   --  Values used to represent individual predefined checks

   All_Checks          : constant := 14;
   --  Value used to represent All_Checks value

   subtype Predefined_Check_Id is Check_Id range 1 .. All_Checks;
   --  Subtype for predefined checks, including All_Checks

   --  The following array contains an entry for each recognized check name
   --  for pragma Suppress. It is used to represent current settings of scope
   --  based suppress actions from pragma Suppress or command line settings.

   --  Note: when Suppress_Array (All_Checks) is True, then generally all other
   --  specific check entries are set True, except for the Elaboration_Check
   --  entry which is set only if an explicit Suppress for this check is given.
   --  The reason for this non-uniformity is that we do not want All_Checks to
   --  suppress elaboration checking when using the static elaboration model.
   --  We recognize only an explicit suppress of Elaboration_Check as a signal
   --  that the static elaboration checking should skip a compile time check.

   type Suppress_Array is array (Predefined_Check_Id) of Boolean;
   pragma Pack (Suppress_Array);

   --  To add a new check type to GNAT, the following steps are required:

   --    1.  Add an entry to Snames spec and body for the new name
   --    2.  Add an entry to the definition of Check_Id above
   --    3.  Add a new function to Checks to handle the new check test
   --    4.  Add a new Do_xxx_Check flag to Sinfo (if required)
   --    5.  Add appropriate checks for the new test

   -----------------------------------
   -- Global Exception Declarations --
   -----------------------------------

   --  This section contains declarations of exceptions that are used
   --  throughout the compiler or in other GNAT tools.

   Unrecoverable_Error : exception;
   --  This exception is raised to immediately terminate the compilation of the
   --  current source program. Used in situations where things are bad enough
   --  that it doesn't seem worth continuing (e.g. max errors reached, or a
   --  required file is not found). Also raised when the compiler finds itself
   --  in trouble after an error (see Comperr).

   Terminate_Program : exception;
   --  This exception is raised to immediately terminate the tool being
   --  executed. Each tool where this exception may be raised must have a
   --  single exception handler that contains only a null statement and that is
   --  the last statement of the program. If needed, procedure Set_Exit_Status
   --  is called with the appropriate exit status before raising
   --  Terminate_Program.

   ---------------------------------
   -- Parameter Mechanism Control --
   ---------------------------------

   --  Function and parameter entities have a field that records the passing
   --  mechanism. See specification of Sem_Mech for full details. The following
   --  subtype is used to represent values of this type:

   subtype Mechanism_Type is Int range -18 .. Int'Last;
   --  Type used to represent a mechanism value. This is a subtype rather than
   --  a type to avoid some annoying processing problems with certain routines
   --  in Einfo (processing them to create the corresponding C).

   ------------------------------
   -- Run-Time Exception Codes --
   ------------------------------

   --  When the code generator generates a run-time exception, it provides a
   --  reason code which is one of the following. This reason code is used to
   --  select the appropriate run-time routine to be called, determining both
   --  the exception to be raised, and the message text to be added.

   --  The prefix CE/PE/SE indicates the exception to be raised
   --    CE = Constraint_Error
   --    PE = Program_Error
   --    SE = Storage_Error

   --  The remaining part of the name indicates the message text to be added,
   --  where all letters are lower case, and underscores are converted to
   --  spaces (for example CE_Invalid_Data adds the text "invalid data").

   --  To add a new code, you need to do the following:

   --    1. Modify the type and subtype declarations below appropriately,
   --       keeping things in alphabetical order.

   --    2. Modify the corresponding definitions in types.h, including the
   --       definition of last_reason_code.

   --    3. Add a new routine in Ada.Exceptions with the appropriate call and
   --       static string constant. Note that there is more than one version
   --       of a-except.adb which must be modified.

   type RT_Exception_Code is
     (CE_Access_Check_Failed,            -- 00
      CE_Access_Parameter_Is_Null,       -- 01
      CE_Discriminant_Check_Failed,      -- 02
      CE_Divide_By_Zero,                 -- 03
      CE_Explicit_Raise,                 -- 04
      CE_Index_Check_Failed,             -- 05
      CE_Invalid_Data,                   -- 06
      CE_Length_Check_Failed,            -- 07
      CE_Null_Exception_Id,              -- 08
      CE_Null_Not_Allowed,               -- 09
      CE_Overflow_Check_Failed,          -- 10
      CE_Partition_Check_Failed,         -- 11
      CE_Range_Check_Failed,             -- 12
      CE_Tag_Check_Failed,               -- 13

      PE_Access_Before_Elaboration,      -- 14
      PE_Accessibility_Check_Failed,     -- 15
      PE_Address_Of_Intrinsic,           -- 16
      PE_All_Guards_Closed,              -- 17
      PE_Bad_Predicated_Generic_Type,    -- 18
      PE_Current_Task_In_Entry_Body,     -- 19
      PE_Duplicated_Entry_Address,       -- 20
      PE_Explicit_Raise,                 -- 21
      PE_Finalize_Raised_Exception,      -- 22
      PE_Implicit_Return,                -- 23
      PE_Misaligned_Address_Value,       -- 24
      PE_Missing_Return,                 -- 25
      PE_Overlaid_Controlled_Object,     -- 26
      PE_Potentially_Blocking_Operation, -- 27
      PE_Stubbed_Subprogram_Called,      -- 28
      PE_Unchecked_Union_Restriction,    -- 29
      PE_Non_Transportable_Actual,       -- 30

      SE_Empty_Storage_Pool,             -- 31
      SE_Explicit_Raise,                 -- 32
      SE_Infinite_Recursion,             -- 33
      SE_Object_Too_Large);              -- 34

   subtype RT_CE_Exceptions is RT_Exception_Code range
     CE_Access_Check_Failed ..
     CE_Tag_Check_Failed;

   subtype RT_PE_Exceptions is RT_Exception_Code range
     PE_Access_Before_Elaboration ..
     PE_Non_Transportable_Actual;

   subtype RT_SE_Exceptions is RT_Exception_Code range
     SE_Empty_Storage_Pool ..
     SE_Object_Too_Large;

end Types;