1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2023, Free Software Foundation, Inc. --
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, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 -- This package contains host independent type definitions which are used
27 -- in more than one unit in the compiler. They are gathered here for easy
28 -- reference, although in some cases the full description is found in the
29 -- relevant module which implements the definition. The main reason that they
30 -- are not in their "natural" specs is that this would cause a lot of inter-
31 -- spec dependencies, and in particular some awkward circular dependencies
32 -- would have to be dealt with.
34 -- WARNING: There is a C version of this package. Any changes to this source
35 -- file must be properly reflected in the C header file types.h
37 -- Note: the declarations in this package reflect an expectation that the host
38 -- machine has an efficient integer base type with a range at least 32 bits
39 -- 2s-complement. If there are any machines for which this is not a correct
40 -- assumption, a significant number of changes will be required.
42 with Ada
.Unchecked_Conversion
;
43 with Ada
.Unchecked_Deallocation
;
49 -------------------------------
50 -- General Use Integer Types --
51 -------------------------------
53 type Int
is range -2 ** 31 .. +2 ** 31 - 1;
54 -- Signed 32-bit integer
56 subtype Nat
is Int
range 0 .. Int
'Last;
57 -- Non-negative Int values
59 subtype Pos
is Int
range 1 .. Int
'Last;
60 -- Positive Int values
62 subtype Nonzero_Int
is Int
with Predicate
=> Nonzero_Int
/= 0;
64 type Int_64
is range -2 ** 63 .. +2 ** 63 - 1;
65 -- Signed 64-bit integer
67 subtype Nat_64
is Int_64
range 0 .. Int_64
'Last;
68 subtype Pos_64
is Int_64
range 1 .. Int_64
'Last;
69 subtype Nonzero_Int_64
is Int_64
with Predicate
=> Nonzero_Int_64
/= 0;
71 type Word
is mod 2 ** 32;
72 -- Unsigned 32-bit integer
74 type Short
is range -32768 .. +32767;
75 for Short
'Size use 16;
76 -- 16-bit signed integer
78 type Byte
is mod 2 ** 8;
80 -- 8-bit unsigned integer
82 type size_t
is mod 2 ** Standard
'Address_Size;
83 -- Memory size value, for use in calls to C routines
85 --------------------------------------
86 -- 8-Bit Character and String Types --
87 --------------------------------------
89 -- We use Standard.Character and Standard.String freely, since we are
90 -- compiling ourselves, and we properly implement the required 8-bit
91 -- character code as required in Ada 95. This section defines a few
92 -- general use constants and subtypes.
94 EOF
: constant Character := ASCII
.SUB
;
95 -- The character SUB (16#1A#) is used in DOS and other systems derived
96 -- from DOS (XP, NT etc) to signal the end of a text file. Internally
97 -- all source files are ended by an EOF character, even on Unix systems.
98 -- An EOF character acts as the end of file only as the last character
99 -- of a source buffer, in any other position, it is treated as a blank
100 -- if it appears between tokens, and as an illegal character otherwise.
101 -- This makes life easier dealing with files that originated from DOS,
102 -- including concatenated files with interspersed EOF characters.
104 subtype Graphic_Character
is Character range ' ' .. '~';
105 -- Graphic characters, as defined in ARM
107 subtype Line_Terminator
is Character range ASCII
.LF
.. ASCII
.CR
;
108 -- Line terminator characters (LF, VT, FF, CR). For further details, see
109 -- the extensive discussion of line termination in the Sinput spec.
111 subtype Upper_Half_Character
is
112 Character range Character'Val (16#
80#
) .. Character'Val (16#FF#
);
113 -- 8-bit Characters with the upper bit set
115 type Character_Ptr
is access all Character;
116 type String_Ptr
is access all String;
117 type String_Ptr_Const
is access constant String;
118 -- Standard character and string pointers
120 procedure Free
is new Ada
.Unchecked_Deallocation
(String, String_Ptr
);
121 -- Procedure for freeing dynamically allocated String values
123 subtype Big_String
is String (Positive);
124 type Big_String_Ptr
is access all Big_String
;
125 -- Virtual type for handling imported big strings. Note that we should
126 -- never have any allocators for this type, but we don't give a storage
127 -- size of zero, since there are legitimate deallocations going on.
129 function To_Big_String_Ptr
is
130 new Ada
.Unchecked_Conversion
(System
.Address
, Big_String_Ptr
);
131 -- Used to obtain Big_String_Ptr values from external addresses
133 subtype Word_Hex_String
is String (1 .. 8);
134 -- Type used to represent Word value as 8 hex digits, with lower case
135 -- letters for the alphabetic cases.
137 function Get_Hex_String
(W
: Word
) return Word_Hex_String
;
138 -- Convert word value to 8-character hex string
140 -----------------------------------------
141 -- Types Used for Text Buffer Handling --
142 -----------------------------------------
144 -- We cannot use type String for text buffers, since we must use the
145 -- standard 32-bit integer as an index value, since we count on all index
146 -- values being the same size.
148 type Text_Ptr
is new Int
;
149 -- Type used for subscripts in text buffer
151 type Text_Buffer
is array (Text_Ptr
range <>) of Character;
152 -- Text buffer used to hold source file or library information file
154 type Text_Buffer_Ptr
is access all Text_Buffer
;
155 -- Text buffers for input files are allocated dynamically and this type
156 -- is used to reference these text buffers.
159 new Ada
.Unchecked_Deallocation
(Text_Buffer
, Text_Buffer_Ptr
);
160 -- Procedure for freeing dynamically allocated text buffers
162 ------------------------------------------
163 -- Types Used for Source Input Handling --
164 ------------------------------------------
166 type Logical_Line_Number
is range 0 .. Int
'Last;
167 for Logical_Line_Number
'Size use 32;
168 -- Line number type, used for storing logical line numbers (i.e. line
169 -- numbers that include effects of any Source_Reference pragmas in the
170 -- source file). The value zero indicates a line containing a source
173 No_Line_Number
: constant Logical_Line_Number
:= 0;
174 -- Special value used to indicate no line number
176 type Physical_Line_Number
is range 1 .. Int
'Last;
177 for Physical_Line_Number
'Size use 32;
178 -- Line number type, used for storing physical line numbers (i.e. line
179 -- numbers in the physical file being compiled, unaffected by the presence
180 -- of source reference pragmas).
182 type Column_Number
is range 0 .. 32767;
183 for Column_Number
'Size use 16;
184 -- Column number (assume that 2**15 - 1 is large enough). The range for
185 -- this type is used to compute Hostparm.Max_Line_Length. See also the
186 -- processing for -gnatyM in Stylesw).
188 No_Column_Number
: constant Column_Number
:= 0;
189 -- Special value used to indicate no column number
191 Source_Align
: constant := 2 ** 12;
192 -- Alignment requirement for source buffers (by keeping source buffers
193 -- aligned, we can optimize the implementation of Get_Source_File_Index.
194 -- See this routine in Sinput for details.
196 subtype Source_Buffer
is Text_Buffer
;
197 -- Type used to store text of a source file. The buffer for the main
198 -- source (the source specified on the command line) has a lower bound
199 -- starting at zero. Subsequent subsidiary sources have lower bounds
200 -- which are one greater than the previous upper bound, rounded up to
201 -- a multiple of Source_Align.
203 type Source_Buffer_Ptr_Var
is access all Source_Buffer
;
204 type Source_Buffer_Ptr
is access constant Source_Buffer
;
205 -- Pointer to source buffer. Source_Buffer_Ptr_Var is used for allocation
206 -- and deallocation; Source_Buffer_Ptr is used for all other uses of source
209 function Null_Source_Buffer_Ptr
(X
: Source_Buffer_Ptr
) return Boolean;
212 function Source_Buffer_Ptr_Equal
(X
, Y
: Source_Buffer_Ptr
) return Boolean
214 -- Squirrel away the predefined "=", for use in Null_Source_Buffer_Ptr.
215 -- Do not call this elsewhere.
217 function "=" (X
, Y
: Source_Buffer_Ptr
) return Boolean is abstract;
218 -- Make "=" abstract. Note that this makes "/=" abstract as well. This is a
219 -- vestige of the zero-origin array indexing we used to use, where "=" is
220 -- always wrong (including the one in Null_Source_Buffer_Ptr). We keep this
221 -- just because we never need to compare Source_Buffer_Ptrs other than to
224 subtype Source_Ptr
is Text_Ptr
;
225 -- Type used to represent a source location, which is a subscript of a
226 -- character in the source buffer. As noted above, different source buffers
227 -- have different ranges, so it is possible to tell from a Source_Ptr value
228 -- which source it refers to. Note that negative numbers are allowed to
229 -- accommodate the following special values.
231 type Source_Span
is record
232 Ptr
, First
, Last
: Source_Ptr
;
234 -- Type used to represent a source span, consisting in a main location Ptr,
235 -- with a First and Last location, such that Ptr in First .. Last
237 function To_Span
(Loc
: Source_Ptr
) return Source_Span
is ((others => Loc
));
238 function To_Span
(Ptr
, First
, Last
: Source_Ptr
) return Source_Span
is
239 ((Ptr
, First
, Last
));
241 No_Location
: constant Source_Ptr
:= -1;
242 -- Value used to indicate no source position set in a node. A test for a
243 -- Source_Ptr value being > No_Location is the approved way to test for a
244 -- standard value that does not include No_Location or any of the following
245 -- special definitions. One important use of No_Location is to label
246 -- generated nodes that we don't want the debugger to see in normal mode
247 -- (very often we conditionalize so that we set No_Location in normal mode
248 -- and the corresponding source line in -gnatD mode).
250 function No
(Loc
: Source_Ptr
) return Boolean is (Loc
= No_Location
);
251 function Present
(Loc
: Source_Ptr
) return Boolean is (not No
(Loc
));
252 -- Tests for No_Location / not No_Location
254 Standard_Location
: constant Source_Ptr
:= -2;
255 -- Used for all nodes in the representation of package Standard other than
256 -- nodes representing the contents of Standard.ASCII. Note that testing for
257 -- a value being <= Standard_Location tests for both Standard_Location and
258 -- for Standard_ASCII_Location.
260 Standard_ASCII_Location
: constant Source_Ptr
:= -3;
261 -- Used for all nodes in the presentation of package Standard.ASCII
263 System_Location
: constant Source_Ptr
:= -4;
264 -- Used to identify locations of pragmas scanned by Targparm, where we know
265 -- the location is in System, but we don't know exactly what line.
267 First_Source_Ptr
: constant Source_Ptr
:= 0;
268 -- Starting source pointer index value for first source program
270 -------------------------------------
271 -- Range Definitions for Tree Data --
272 -------------------------------------
274 -- The tree has fields that can hold any of the following types:
276 -- Pointers to other tree nodes (type Node_Id)
277 -- List pointers (type List_Id)
278 -- Element list pointers (type Elist_Id)
279 -- Names (type Name_Id)
280 -- Strings (type String_Id)
281 -- Universal integers (type Uint)
282 -- Universal reals (type Ureal)
284 -- These types are represented as integer indices into various tables.
285 -- However, they should be treated as private, except in a few documented
286 -- cases. In particular it is usually inappropriate to perform arithmetic
287 -- operations using these types. One exception is in computing hash
288 -- functions of these types.
290 -- In most contexts, the strongly typed interface determines which of these
291 -- types is present. However, there are some situations (involving untyped
292 -- traversals of the tree), where it is convenient to be easily able to
293 -- distinguish these values. The underlying representation in all cases is
294 -- an integer type Union_Id, and we ensure that the range of the various
295 -- possible values for each of the above types is disjoint (except that
296 -- List_Id and Node_Id overlap at Empty) so that this distinction is
299 -- Note: it is also helpful for debugging purposes to make these ranges
300 -- distinct. If a bug leads to misidentification of a value, then it will
301 -- typically result in an out of range value and a Constraint_Error.
303 -- The range of Node_Id is most of the nonnegative integers. The other
304 -- ranges are negative. Uint has a very large range, because a substantial
305 -- part of this range is used to store direct values; see Uintp for
306 -- details. The other types have 100 million values, which should be
309 type Union_Id
is new Int
;
310 -- The type in the tree for a union of possible ID values
312 -- Following are the Low and High bounds of the various ranges.
314 List_Low_Bound
: constant := -099_999_999
;
315 -- The List_Id values are subscripts into an array of list headers which
316 -- has List_Low_Bound as its lower bound.
318 List_High_Bound
: constant := 0;
319 -- Maximum List_Id subscript value. The ranges of List_Id and Node_Id
320 -- overlap by one element (with value zero), which is used both for the
321 -- Empty node, and for No_List. The fact that the same value is used is
322 -- convenient because it means that the default value of Empty applies to
323 -- both nodes and lists, and also is more efficient to test for.
325 Node_Low_Bound
: constant := 0;
326 -- The tree Id values start at zero, because we use zero for Empty (to
327 -- allow a zero test for Empty).
329 Node_High_Bound
: constant := 1_999_999_999
;
331 Elist_Low_Bound
: constant := -199_999_999
;
332 -- The Elist_Id values are subscripts into an array of elist headers which
333 -- has Elist_Low_Bound as its lower bound.
335 Elist_High_Bound
: constant := -100_000_000
;
337 Elmt_Low_Bound
: constant := -299_999_999
;
338 -- Low bound of element Id values. The use of these values is internal to
339 -- the Elists package, but the definition of the range is included here
340 -- since it must be disjoint from other Id values. The Elmt_Id values are
341 -- subscripts into an array of list elements which has this as lower bound.
343 Elmt_High_Bound
: constant := -200_000_000
;
345 Names_Low_Bound
: constant := -399_999_999
;
347 Names_High_Bound
: constant := -300_000_000
;
349 Strings_Low_Bound
: constant := -499_999_999
;
351 Strings_High_Bound
: constant := -400_000_000
;
353 Ureal_Low_Bound
: constant := -599_999_999
;
355 Ureal_High_Bound
: constant := -500_000_000
;
357 Uint_Low_Bound
: constant := -2_100_000_000
;
358 -- Low bound for Uint values
360 Uint_Table_Start
: constant := -699_999_999
;
361 -- Location where table entries for universal integers start (see
362 -- Uintp spec for details of the representation of Uint values).
364 Uint_High_Bound
: constant := -600_000_000
;
366 -- The following subtype definitions are used to provide convenient names
367 -- for membership tests on Int values to see what data type range they
368 -- lie in. Such tests appear only in the lowest level packages.
370 subtype List_Range
is Union_Id
371 range List_Low_Bound
.. List_High_Bound
;
373 subtype Node_Range
is Union_Id
374 range Node_Low_Bound
.. Node_High_Bound
;
376 subtype Elist_Range
is Union_Id
377 range Elist_Low_Bound
.. Elist_High_Bound
;
379 subtype Elmt_Range
is Union_Id
380 range Elmt_Low_Bound
.. Elmt_High_Bound
;
382 subtype Names_Range
is Union_Id
383 range Names_Low_Bound
.. Names_High_Bound
;
385 subtype Strings_Range
is Union_Id
386 range Strings_Low_Bound
.. Strings_High_Bound
;
388 subtype Uint_Range
is Union_Id
389 range Uint_Low_Bound
.. Uint_High_Bound
;
391 subtype Ureal_Range
is Union_Id
392 range Ureal_Low_Bound
.. Ureal_High_Bound
;
394 -----------------------------
395 -- Types for Atree Package --
396 -----------------------------
398 -- Node_Id values are used to identify nodes in the tree. They are
399 -- subscripts into the Nodes table declared in package Atree. Note that
400 -- the special values Empty and Error are subscripts into this table.
401 -- See package Atree for further details.
403 type Node_Id
is range Node_Low_Bound
.. Node_High_Bound
with Size
=> 32;
404 -- Type used to identify nodes in the tree
406 subtype Entity_Id
is Node_Id
;
407 -- A synonym for node types, used in the Einfo package to refer to nodes
408 -- that are entities (i.e. nodes with an Nkind of N_Defining_xxx).
410 -- Note that Sinfo.Nodes.N_Entity_Id is the same as Entity_Id, except it
411 -- has a predicate requiring the correct Nkind. Opt_N_Entity_Id is the same
412 -- as N_Entity_Id, except it allows Empty. (Sinfo.Nodes is generated by the
415 subtype Node_Or_Entity_Id
is Node_Id
;
416 -- A synonym for node types, used in cases where a given value may be used
417 -- to represent either a node or an entity. We like to minimize such uses
418 -- for obvious reasons of logical type consistency, but where such uses
419 -- occur, they should be documented by use of this type.
421 Empty
: constant Node_Id
:= Node_Low_Bound
;
422 -- Used to indicate null node. A node is actually allocated with this
423 -- Id value, so that Nkind (Empty) = N_Empty. Note that Node_Low_Bound
424 -- is zero, so Empty = No_List = zero.
426 Empty_List_Or_Node
: constant := 0;
427 -- This constant is used in situations (e.g. initializing empty fields)
428 -- where the value set will be used to represent either an empty node or
429 -- a non-existent list, depending on the context.
431 Error
: constant Node_Id
:= Node_Low_Bound
+ 1;
432 -- Used to indicate an error in the source program. A node is actually
433 -- allocated with this Id value, so that Nkind (Error) = N_Error.
435 Empty_Or_Error
: constant Node_Id
:= Error
;
436 -- Since Empty and Error are the first two Node_Id values, the test for
437 -- N <= Empty_Or_Error tests to see if N is Empty or Error. This definition
438 -- provides convenient self-documentation for such tests.
440 First_Node_Id
: constant Node_Id
:= Node_Low_Bound
;
441 -- Subscript of first allocated node. Note that Empty and Error are both
442 -- allocated nodes, whose Nkind fields can be accessed without error.
444 ------------------------------
445 -- Types for Nlists Package --
446 ------------------------------
448 -- List_Id values are used to identify node lists stored in the tree, so
449 -- that each node can be on at most one such list (see package Nlists for
450 -- further details). Note that the special value Error_List is a subscript
451 -- in this table, but the value No_List is *not* a valid subscript, and any
452 -- attempt to apply list operations to No_List will cause a (detected)
455 type List_Id
is range List_Low_Bound
.. List_High_Bound
with Size
=> 32;
456 -- Type used to identify a node list
458 No_List
: constant List_Id
:= List_High_Bound
;
459 -- Used to indicate absence of a list. Note that the value is zero, which
460 -- is the same as Empty, which is helpful in initializing nodes where a
461 -- value of zero can represent either an empty node or an empty list.
463 Error_List
: constant List_Id
:= List_Low_Bound
;
464 -- Used to indicate that there was an error in the source program in a
465 -- context which would normally require a list. This node appears to be
466 -- an empty list to the list operations (a null list is actually allocated
467 -- which has this Id value).
469 First_List_Id
: constant List_Id
:= Error_List
;
470 -- Subscript of first allocated list header
472 ------------------------------
473 -- Types for Elists Package --
474 ------------------------------
476 -- Element list Id values are used to identify element lists stored outside
477 -- of the tree, allowing nodes to be members of more than one such list
478 -- (see package Elists for further details).
480 type Elist_Id
is range Elist_Low_Bound
.. Elist_High_Bound
with Size
=> 32;
481 -- Type used to identify an element list (Elist header table subscript)
483 No_Elist
: constant Elist_Id
:= Elist_Low_Bound
;
484 -- Used to indicate absence of an element list. Note that this is not an
485 -- actual Elist header, so element list operations on this value are not
488 First_Elist_Id
: constant Elist_Id
:= No_Elist
+ 1;
489 -- Subscript of first allocated Elist header
491 -- Element Id values are used to identify individual elements of an element
492 -- list (see package Elists for further details).
494 type Elmt_Id
is range Elmt_Low_Bound
.. Elmt_High_Bound
;
495 -- Type used to identify an element list
497 No_Elmt
: constant Elmt_Id
:= Elmt_Low_Bound
;
498 -- Used to represent empty element
500 First_Elmt_Id
: constant Elmt_Id
:= No_Elmt
+ 1;
501 -- Subscript of first allocated Elmt table entry
503 -------------------------------
504 -- Types for Stringt Package --
505 -------------------------------
507 -- String_Id values are used to identify entries in the strings table. They
508 -- are subscripts into the Strings table defined in package Stringt.
510 type String_Id
is range Strings_Low_Bound
.. Strings_High_Bound
512 -- Type used to identify entries in the strings table
514 No_String
: constant String_Id
:= Strings_Low_Bound
;
515 -- Used to indicate missing string Id. Note that the value zero is used
516 -- to indicate a missing data value for all the Int types in this section.
518 First_String_Id
: constant String_Id
:= No_String
+ 1;
519 -- First subscript allocated in string table
521 -------------------------
522 -- Character Code Type --
523 -------------------------
525 -- The type Char is used for character data internally in the compiler, but
526 -- character codes in the source are represented by the Char_Code type.
527 -- Each character literal in the source is interpreted as being one of the
528 -- 16#7FFF_FFFF# possible Wide_Wide_Character codes, and a unique Integer
529 -- value is assigned, corresponding to the UTF-32 value, which also
530 -- corresponds to the Pos value in the Wide_Wide_Character type, and also
531 -- corresponds to the Pos value in the Wide_Character and Character types
532 -- for values that are in appropriate range. String literals are similarly
533 -- interpreted as a sequence of such codes.
535 type Char_Code_Base
is mod 2 ** 32;
536 for Char_Code_Base
'Size use 32;
538 subtype Char_Code
is Char_Code_Base
range 0 .. 16#
7FFF_FFFF#
;
539 for Char_Code
'Value_Size use 32;
540 for Char_Code
'Object_Size use 32;
542 function Get_Char_Code
(C
: Character) return Char_Code
;
543 pragma Inline
(Get_Char_Code
);
544 -- Function to obtain internal character code from source character. For
545 -- the moment, the internal character code is simply the Pos value of the
546 -- input source character, but we provide this interface for possible
547 -- later support of alternative character sets.
549 function In_Character_Range
(C
: Char_Code
) return Boolean;
550 pragma Inline
(In_Character_Range
);
551 -- Determines if the given character code is in range of type Character,
552 -- and if so, returns True. If not, returns False.
554 function In_Wide_Character_Range
(C
: Char_Code
) return Boolean;
555 pragma Inline
(In_Wide_Character_Range
);
556 -- Determines if the given character code is in range of the type
557 -- Wide_Character, and if so, returns True. If not, returns False.
559 function Get_Character
(C
: Char_Code
) return Character;
560 pragma Inline
(Get_Character
);
561 -- For a character C that is in Character range (see above function), this
562 -- function returns the corresponding Character value. It is an error to
563 -- call Get_Character if C is not in Character range.
565 function Get_Wide_Character
(C
: Char_Code
) return Wide_Character;
566 -- For a character C that is in Wide_Character range (see above function),
567 -- this function returns the corresponding Wide_Character value. It is an
568 -- error to call Get_Wide_Character if C is not in Wide_Character range.
570 ---------------------------------------
571 -- Types used for Library Management --
572 ---------------------------------------
574 type Unit_Number_Type
is new Int
range -1 .. Int
'Last;
575 -- Unit number. The main source is unit 0, and subsidiary sources have
576 -- non-zero numbers starting with 1. Unit numbers are used to index the
577 -- Units table in package Lib.
579 Main_Unit
: constant Unit_Number_Type
:= 0;
580 -- Unit number value for main unit
582 No_Unit
: constant Unit_Number_Type
:= -1;
583 -- Special value used to signal no unit
585 type Source_File_Index
is new Int
range -1 .. Int
'Last;
586 -- Type used to index the source file table (see package Sinput)
588 No_Source_File
: constant Source_File_Index
:= 0;
589 -- Value used to indicate no source file present
591 No_Access_To_Source_File
: constant Source_File_Index
:= -1;
592 -- Value used to indicate a source file is present but unreadable
594 -----------------------------------
595 -- Representation of Time Stamps --
596 -----------------------------------
598 -- All compiled units are marked with a time stamp which is derived from
599 -- the source file (we assume that the host system has the concept of a
600 -- file time stamp which is modified when a file is modified). These
601 -- time stamps are used to ensure consistency of the set of units that
602 -- constitutes a library. Time stamps are 14-character strings with
603 -- with the following format:
608 -- MM month (2 digits 01-12)
609 -- DD day (2 digits 01-31)
610 -- HH hour (2 digits 00-23)
611 -- MM minutes (2 digits 00-59)
612 -- SS seconds (2 digits 00-59)
614 -- In the case of Unix systems (and other systems which keep the time in
615 -- GMT), the time stamp is the GMT time of the file, not the local time.
616 -- This solves problems in using libraries across networks with clients
617 -- spread across multiple time-zones.
619 Time_Stamp_Length
: constant := 14;
620 -- Length of time stamp value
622 subtype Time_Stamp_Index
is Natural range 1 .. Time_Stamp_Length
;
623 type Time_Stamp_Type
is new String (Time_Stamp_Index
);
624 -- Type used to represent time stamp
626 Empty_Time_Stamp
: constant Time_Stamp_Type
:= (others => ' ');
627 -- Value representing an empty or missing time stamp. Looks less than any
628 -- real time stamp if two time stamps are compared. Note that although this
629 -- is not private, clients should not rely on the exact way in which this
630 -- string is represented, and instead should use the subprograms below.
632 Dummy_Time_Stamp
: constant Time_Stamp_Type
:= (others => '0');
633 -- This is used for dummy time stamp values used in the D lines for
634 -- non-existent files, and is intended to be an impossible value.
636 function "=" (Left
, Right
: Time_Stamp_Type
) return Boolean;
637 function "<=" (Left
, Right
: Time_Stamp_Type
) return Boolean;
638 function ">=" (Left
, Right
: Time_Stamp_Type
) return Boolean;
639 function "<" (Left
, Right
: Time_Stamp_Type
) return Boolean;
640 function ">" (Left
, Right
: Time_Stamp_Type
) return Boolean;
641 -- Comparison functions on time stamps. Note that two time stamps are
642 -- defined as being equal if they have the same day/month/year and the
643 -- hour/minutes/seconds values are within 2 seconds of one another. This
644 -- deals with rounding effects in library file time stamps caused by
645 -- copying operations during installation. We have particularly noticed
646 -- that WinNT seems susceptible to such changes.
648 -- Note: the Empty_Time_Stamp value looks equal to itself, and less than
649 -- any non-empty time stamp value.
651 procedure Split_Time_Stamp
652 (TS
: Time_Stamp_Type
;
659 -- Given a time stamp, decompose it into its components
661 procedure Make_Time_Stamp
668 TS
: out Time_Stamp_Type
);
669 -- Given the components of a time stamp, initialize the value
671 -------------------------------------
672 -- Types used for Check Management --
673 -------------------------------------
675 type Check_Id
is new Nat
;
676 -- Type used to represent a check id
678 No_Check_Id
: constant := 0;
679 -- Check_Id value used to indicate no check
681 Access_Check
: constant := 1;
682 Accessibility_Check
: constant := 2;
683 Alignment_Check
: constant := 3;
684 Allocation_Check
: constant := 4;
685 Atomic_Synchronization
: constant := 5;
686 Characters_Assertion_Check
: constant := 6;
687 Containers_Assertion_Check
: constant := 7;
688 Discriminant_Check
: constant := 8;
689 Division_Check
: constant := 9;
690 Duplicated_Tag_Check
: constant := 10;
691 Elaboration_Check
: constant := 11;
692 Index_Check
: constant := 12;
693 Interfaces_Assertion_Check
: constant := 13;
694 IO_Assertion_Check
: constant := 14;
695 Length_Check
: constant := 15;
696 Numerics_Assertion_Check
: constant := 16;
697 Overflow_Check
: constant := 17;
698 Predicate_Check
: constant := 18;
699 Program_Error_Check
: constant := 19;
700 Range_Check
: constant := 20;
701 Storage_Check
: constant := 21;
702 Strings_Assertion_Check
: constant := 22;
703 System_Assertion_Check
: constant := 23;
704 Tag_Check
: constant := 24;
705 Validity_Check
: constant := 25;
706 Container_Checks
: constant := 26;
707 Tampering_Check
: constant := 27;
708 Tasking_Check
: constant := 28;
709 -- Values used to represent individual predefined checks (including the
710 -- setting of Atomic_Synchronization, which is implemented internally using
711 -- a "check" whose name is Atomic_Synchronization).
713 All_Checks
: constant := 29;
714 -- Value used to represent All_Checks value
716 subtype Predefined_Check_Id
is Check_Id
range 1 .. All_Checks
;
717 -- Subtype for predefined checks, including All_Checks
719 -- The following array contains an entry for each recognized check name
720 -- for pragma Suppress. It is used to represent current settings of scope
721 -- based suppress actions from pragma Suppress or command line settings.
723 -- Note: when Suppress_Array (All_Checks) is True, then generally all other
724 -- specific check entries are set True, except for the Elaboration_Check
725 -- entry which is set only if an explicit Suppress for this check is given.
726 -- The reason for this non-uniformity is that we do not want All_Checks to
727 -- suppress elaboration checking when using the static elaboration model.
728 -- We recognize only an explicit suppress of Elaboration_Check as a signal
729 -- that the static elaboration checking should skip a compile time check.
731 type Suppress_Array
is array (Predefined_Check_Id
) of Boolean;
732 pragma Pack
(Suppress_Array
);
734 -- To add a new check type to GNAT, the following steps are required:
736 -- 1. Add an entry to Snames spec for the new name
737 -- 2. Add an entry to the definition of Check_Id above (very important:
738 -- these definitions should be in the same order in Snames and here)
739 -- 3. Add a new function to Checks to handle the new check test
740 -- 4. Add a new Do_xxx_Check flag to Sinfo (if required)
741 -- 5. Add appropriate checks for the new test
743 -- The following provides precise details on the mode used to generate
744 -- code for intermediate operations in expressions for signed integer
745 -- arithmetic (and how to generate overflow checks if enabled). Note
746 -- that this only affects handling of intermediate results. The final
747 -- result must always fit within the target range, and if overflow
748 -- checking is enabled, the check on the final result is against this
751 type Overflow_Mode_Type
is (
753 -- Dummy value used during initialization process to show that the
754 -- corresponding value has not yet been initialized.
757 -- Operations are done in the base type of the subexpression. If
758 -- overflow checks are enabled, then the check is against the range
759 -- of this base type.
762 -- Where appropriate, intermediate arithmetic operations are performed
763 -- with an extended range, using Long_Long_Integer if necessary. If
764 -- overflow checking is enabled, then the check is against the range
765 -- of Long_Long_Integer.
768 -- In this mode arbitrary precision arithmetic is used as needed to
769 -- ensure that it is impossible for intermediate arithmetic to cause an
770 -- overflow. In this mode, intermediate expressions are not affected by
771 -- the overflow checking mode, since overflows are eliminated.
773 subtype Minimized_Or_Eliminated
is
774 Overflow_Mode_Type
range Minimized
.. Eliminated
;
775 -- Define subtype so that clients don't need to know ordering. Note that
776 -- Overflow_Mode_Type is not marked as an ordered enumeration type.
778 -- The following structure captures the state of check suppression or
779 -- activation at a particular point in the program execution.
781 type Suppress_Record
is record
782 Suppress
: Suppress_Array
;
783 -- Indicates suppression status of each possible check
785 Overflow_Mode_General
: Overflow_Mode_Type
;
786 -- This field indicates the mode for handling code generation and
787 -- overflow checking (if enabled) for intermediate expression values.
788 -- This applies to general expressions outside assertions.
790 Overflow_Mode_Assertions
: Overflow_Mode_Type
;
791 -- This field indicates the mode for handling code generation and
792 -- overflow checking (if enabled) for intermediate expression values.
793 -- This applies to any expression occurring inside assertions.
796 -----------------------------------
797 -- Global Exception Declarations --
798 -----------------------------------
800 -- This section contains declarations of exceptions that are used
801 -- throughout the compiler or in other GNAT tools.
803 Unrecoverable_Error
: exception;
804 -- This exception is raised to immediately terminate the compilation of the
805 -- current source program. Used in situations where things are bad enough
806 -- that it doesn't seem worth continuing (e.g. max errors reached, or a
807 -- required file is not found). Also raised when the compiler finds itself
808 -- in trouble after an error (see Comperr).
810 Terminate_Program
: exception;
811 -- This exception is raised to immediately terminate the tool being
812 -- executed. Each tool where this exception may be raised must have a
813 -- single exception handler that contains only a null statement and that is
814 -- the last statement of the program. If needed, procedure Set_Exit_Status
815 -- is called with the appropriate exit status before raising
816 -- Terminate_Program.
818 ---------------------------------
819 -- Parameter Mechanism Control --
820 ---------------------------------
822 -- Function and parameter entities have a field that records the passing
823 -- mechanism. See specification of Sem_Mech for full details. The following
824 -- subtype is used to represent values of this type:
826 subtype Mechanism_Type
is Int
range -2 .. Int
'Last;
827 -- Type used to represent a mechanism value. This is a subtype rather than
828 -- a type to avoid some annoying processing problems with certain routines
829 -- in Einfo (processing them to create the corresponding C). The values in
830 -- the range -2 .. 0 are used to represent mechanism types declared as
831 -- named constants in the spec of Sem_Mech. Positive values are used for
832 -- the case of a pragma C_Pass_By_Copy that sets a threshold value for the
833 -- mechanism to be used. For example if pragma C_Pass_By_Copy (32) is given
834 -- then Default_C_Record_Mechanism is set to 32, and the meaning is to use
835 -- By_Reference if the size is greater than 32, and By_Copy otherwise.
837 ---------------------------------
838 -- Component_Alignment Control --
839 ---------------------------------
841 -- There are four types of alignment possible for array and record
842 -- types, and a field in the type entities contains a value of the
843 -- following type indicating which alignment choice applies. For full
844 -- details of the meaning of these alignment types, see description
845 -- of the Component_Alignment pragma.
847 type Component_Alignment_Kind
is (
848 Calign_Default
, -- default alignment
849 Calign_Component_Size
, -- natural alignment for component size
850 Calign_Component_Size_4
, -- natural for size <= 4, 4 for size >= 4
851 Calign_Storage_Unit
); -- all components byte aligned
853 -----------------------------------
854 -- Floating Point Representation --
855 -----------------------------------
857 type Float_Rep_Kind
is (IEEE_Binary
);
858 -- The only one supported now is IEEE 754p conforming binary format, but
859 -- other formats were supported in the past, and could conceivably be
860 -- supported in the future, so we keep this singleton enumeration type.
862 ----------------------------
863 -- Small_Paren_Count_Type --
864 ----------------------------
866 -- See Paren_Count in Atree for documentation
868 subtype Small_Paren_Count_Type
is Nat
range 0 .. 3;
870 ------------------------------
871 -- Run-Time Exception Codes --
872 ------------------------------
874 -- When the code generator generates a run-time exception, it provides a
875 -- reason code which is one of the following. This reason code is used to
876 -- select the appropriate run-time routine to be called, determining both
877 -- the exception to be raised, and the message text to be added.
879 -- The prefix CE/PE/SE indicates the exception to be raised
880 -- CE = Constraint_Error
881 -- PE = Program_Error
882 -- SE = Storage_Error
884 -- The remaining part of the name indicates the message text to be added,
885 -- where all letters are lower case, and underscores are converted to
886 -- spaces (for example CE_Invalid_Data adds the text "invalid data").
888 -- To add a new code, you need to do the following:
890 -- 1. Assign a new number to the reason. Do not renumber existing codes,
891 -- since this causes compatibility/bootstrap issues, so always add the
892 -- new code at the end of the list.
894 -- 2. Update the contents of the array Kind
896 -- 3. Modify the corresponding definitions in types.h, including the
897 -- definition of last_reason_code.
899 -- 4. Add the name of the routines in exp_ch11.Get_RT_Exception_Name
901 -- 5. Add a new routine in Ada.Exceptions with the appropriate call and
902 -- static string constant. Note that there is more than one version
903 -- of a-except.adb which must be modified.
905 -- Note on ordering of references. For the tables in Ada.Exceptions units,
906 -- usually the ordering does not matter, and we use the same ordering as
909 type RT_Exception_Code
is
910 (CE_Access_Check_Failed
, -- 00
911 CE_Access_Parameter_Is_Null
, -- 01
912 CE_Discriminant_Check_Failed
, -- 02
913 CE_Divide_By_Zero
, -- 03
914 CE_Explicit_Raise
, -- 04
915 CE_Index_Check_Failed
, -- 05
916 CE_Invalid_Data
, -- 06
917 CE_Length_Check_Failed
, -- 07
918 CE_Null_Exception_Id
, -- 08
919 CE_Null_Not_Allowed
, -- 09
921 CE_Overflow_Check_Failed
, -- 10
922 CE_Partition_Check_Failed
, -- 11
923 CE_Range_Check_Failed
, -- 12
924 CE_Tag_Check_Failed
, -- 13
925 PE_Access_Before_Elaboration
, -- 14
926 PE_Accessibility_Check_Failed
, -- 15
927 PE_Address_Of_Intrinsic
, -- 16
928 PE_Aliased_Parameters
, -- 17
929 PE_All_Guards_Closed
, -- 18
930 PE_Bad_Predicated_Generic_Type
, -- 19
932 PE_Current_Task_In_Entry_Body
, -- 20
933 PE_Duplicated_Entry_Address
, -- 21
934 PE_Explicit_Raise
, -- 22
935 PE_Finalize_Raised_Exception
, -- 23
936 PE_Implicit_Return
, -- 24
937 PE_Misaligned_Address_Value
, -- 25
938 PE_Missing_Return
, -- 26
939 PE_Overlaid_Controlled_Object
, -- 27
940 PE_Potentially_Blocking_Operation
, -- 28
941 PE_Stubbed_Subprogram_Called
, -- 29
943 PE_Unchecked_Union_Restriction
, -- 30
944 PE_Non_Transportable_Actual
, -- 31
945 SE_Empty_Storage_Pool
, -- 32
946 SE_Explicit_Raise
, -- 33
947 SE_Infinite_Recursion
, -- 34
948 SE_Object_Too_Large
, -- 35
949 PE_Stream_Operation_Not_Allowed
, -- 36
950 PE_Build_In_Place_Mismatch
); -- 37
951 pragma Convention
(C
, RT_Exception_Code
);
953 Last_Reason_Code
: constant :=
954 RT_Exception_Code
'Pos (RT_Exception_Code
'Last);
957 type Reason_Kind
is (CE_Reason
, PE_Reason
, SE_Reason
);
958 -- Categorization of reason codes by exception raised
960 Rkind
: constant array (RT_Exception_Code
range <>) of Reason_Kind
:=
961 (CE_Access_Check_Failed
=> CE_Reason
,
962 CE_Access_Parameter_Is_Null
=> CE_Reason
,
963 CE_Discriminant_Check_Failed
=> CE_Reason
,
964 CE_Divide_By_Zero
=> CE_Reason
,
965 CE_Explicit_Raise
=> CE_Reason
,
966 CE_Index_Check_Failed
=> CE_Reason
,
967 CE_Invalid_Data
=> CE_Reason
,
968 CE_Length_Check_Failed
=> CE_Reason
,
969 CE_Null_Exception_Id
=> CE_Reason
,
970 CE_Null_Not_Allowed
=> CE_Reason
,
971 CE_Overflow_Check_Failed
=> CE_Reason
,
972 CE_Partition_Check_Failed
=> CE_Reason
,
973 CE_Range_Check_Failed
=> CE_Reason
,
974 CE_Tag_Check_Failed
=> CE_Reason
,
976 PE_Access_Before_Elaboration
=> PE_Reason
,
977 PE_Accessibility_Check_Failed
=> PE_Reason
,
978 PE_Address_Of_Intrinsic
=> PE_Reason
,
979 PE_Aliased_Parameters
=> PE_Reason
,
980 PE_All_Guards_Closed
=> PE_Reason
,
981 PE_Bad_Predicated_Generic_Type
=> PE_Reason
,
982 PE_Current_Task_In_Entry_Body
=> PE_Reason
,
983 PE_Duplicated_Entry_Address
=> PE_Reason
,
984 PE_Explicit_Raise
=> PE_Reason
,
985 PE_Finalize_Raised_Exception
=> PE_Reason
,
986 PE_Implicit_Return
=> PE_Reason
,
987 PE_Misaligned_Address_Value
=> PE_Reason
,
988 PE_Missing_Return
=> PE_Reason
,
989 PE_Overlaid_Controlled_Object
=> PE_Reason
,
990 PE_Potentially_Blocking_Operation
=> PE_Reason
,
991 PE_Stubbed_Subprogram_Called
=> PE_Reason
,
992 PE_Unchecked_Union_Restriction
=> PE_Reason
,
993 PE_Non_Transportable_Actual
=> PE_Reason
,
994 PE_Stream_Operation_Not_Allowed
=> PE_Reason
,
995 PE_Build_In_Place_Mismatch
=> PE_Reason
,
997 SE_Empty_Storage_Pool
=> SE_Reason
,
998 SE_Explicit_Raise
=> SE_Reason
,
999 SE_Infinite_Recursion
=> SE_Reason
,
1000 SE_Object_Too_Large
=> SE_Reason
);
1002 -- Types for field offsets/sizes used in Seinfo, Sinfo.Nodes and
1005 type Field_Offset
is new Nat
;
1006 -- Offset of a node field, in units of the size of the field, which is
1007 -- always a power of 2.
1009 subtype Node_Offset
is Field_Offset
'Base range 1 .. Field_Offset
'Base'Last;
1011 subtype Slot_Count is Field_Offset;
1012 -- Count of number of slots. Same type as Field_Offset to avoid
1013 -- proliferation of type conversions.
1015 subtype Field_Size_In_Bits is Field_Offset with Predicate =>
1016 Field_Size_In_Bits in 1 | 2 | 4 | 8 | 32;
1018 subtype Opt_Field_Offset is Field_Offset'Base range -1 .. Field_Offset'Last;
1019 No_Field_Offset : constant Opt_Field_Offset := Opt_Field_Offset'First;
1021 type Offset_Array_Index is new Nat;
1022 type Offset_Array is
1023 array (Offset_Array_Index range <>) of Opt_Field_Offset;