1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- T Y P E S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2019, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This package contains host independent type definitions which are used 33-- in more than one unit in the compiler. They are gathered here for easy 34-- reference, although in some cases the full description is found in the 35-- relevant module which implements the definition. The main reason that they 36-- are not in their "natural" specs is that this would cause a lot of inter- 37-- spec dependencies, and in particular some awkward circular dependencies 38-- would have to be dealt with. 39 40-- WARNING: There is a C version of this package. Any changes to this source 41-- file must be properly reflected in the C header file types.h declarations. 42 43-- Note: the declarations in this package reflect an expectation that the host 44-- machine has an efficient integer base type with a range at least 32 bits 45-- 2s-complement. If there are any machines for which this is not a correct 46-- assumption, a significant number of changes will be required. 47 48with System; 49with Unchecked_Conversion; 50with Unchecked_Deallocation; 51 52package Types is 53 pragma Preelaborate; 54 55 ------------------------------- 56 -- General Use Integer Types -- 57 ------------------------------- 58 59 type Int is range -2 ** 31 .. +2 ** 31 - 1; 60 -- Signed 32-bit integer 61 62 subtype Nat is Int range 0 .. Int'Last; 63 -- Non-negative Int values 64 65 subtype Pos is Int range 1 .. Int'Last; 66 -- Positive Int values 67 68 type Word is mod 2 ** 32; 69 -- Unsigned 32-bit integer 70 71 type Short is range -32768 .. +32767; 72 for Short'Size use 16; 73 -- 16-bit signed integer 74 75 type Byte is mod 2 ** 8; 76 for Byte'Size use 8; 77 -- 8-bit unsigned integer 78 79 type size_t is mod 2 ** Standard'Address_Size; 80 -- Memory size value, for use in calls to C routines 81 82 -------------------------------------- 83 -- 8-Bit Character and String Types -- 84 -------------------------------------- 85 86 -- We use Standard.Character and Standard.String freely, since we are 87 -- compiling ourselves, and we properly implement the required 8-bit 88 -- character code as required in Ada 95. This section defines a few 89 -- general use constants and subtypes. 90 91 EOF : constant Character := ASCII.SUB; 92 -- The character SUB (16#1A#) is used in DOS and other systems derived 93 -- from DOS (XP, NT etc) to signal the end of a text file. Internally 94 -- all source files are ended by an EOF character, even on Unix systems. 95 -- An EOF character acts as the end of file only as the last character 96 -- of a source buffer, in any other position, it is treated as a blank 97 -- if it appears between tokens, and as an illegal character otherwise. 98 -- This makes life easier dealing with files that originated from DOS, 99 -- including concatenated files with interspersed EOF characters. 100 101 subtype Graphic_Character is Character range ' ' .. '~'; 102 -- Graphic characters, as defined in ARM 103 104 subtype Line_Terminator is Character range ASCII.LF .. ASCII.CR; 105 -- Line terminator characters (LF, VT, FF, CR). For further details, see 106 -- the extensive discussion of line termination in the Sinput spec. 107 108 subtype Upper_Half_Character is 109 Character range Character'Val (16#80#) .. Character'Val (16#FF#); 110 -- 8-bit Characters with the upper bit set 111 112 type Character_Ptr is access all Character; 113 type String_Ptr is access all String; 114 type String_Ptr_Const is access constant String; 115 -- Standard character and string pointers 116 117 procedure Free is new Unchecked_Deallocation (String, String_Ptr); 118 -- Procedure for freeing dynamically allocated String values 119 120 subtype Big_String is String (Positive); 121 type Big_String_Ptr is access all Big_String; 122 -- Virtual type for handling imported big strings. Note that we should 123 -- never have any allocators for this type, but we don't give a storage 124 -- size of zero, since there are legitimate deallocations going on. 125 126 function To_Big_String_Ptr is 127 new Unchecked_Conversion (System.Address, Big_String_Ptr); 128 -- Used to obtain Big_String_Ptr values from external addresses 129 130 subtype Word_Hex_String is String (1 .. 8); 131 -- Type used to represent Word value as 8 hex digits, with lower case 132 -- letters for the alphabetic cases. 133 134 function Get_Hex_String (W : Word) return Word_Hex_String; 135 -- Convert word value to 8-character hex string 136 137 ----------------------------------------- 138 -- Types Used for Text Buffer Handling -- 139 ----------------------------------------- 140 141 -- We cannot use type String for text buffers, since we must use the 142 -- standard 32-bit integer as an index value, since we count on all index 143 -- values being the same size. 144 145 type Text_Ptr is new Int; 146 -- Type used for subscripts in text buffer 147 148 type Text_Buffer is array (Text_Ptr range <>) of Character; 149 -- Text buffer used to hold source file or library information file 150 151 type Text_Buffer_Ptr is access all Text_Buffer; 152 -- Text buffers for input files are allocated dynamically and this type 153 -- is used to reference these text buffers. 154 155 procedure Free is new Unchecked_Deallocation (Text_Buffer, Text_Buffer_Ptr); 156 -- Procedure for freeing dynamically allocated text buffers 157 158 ------------------------------------------ 159 -- Types Used for Source Input Handling -- 160 ------------------------------------------ 161 162 type Logical_Line_Number is range 0 .. Int'Last; 163 for Logical_Line_Number'Size use 32; 164 -- Line number type, used for storing logical line numbers (i.e. line 165 -- numbers that include effects of any Source_Reference pragmas in the 166 -- source file). The value zero indicates a line containing a source 167 -- reference pragma. 168 169 No_Line_Number : constant Logical_Line_Number := 0; 170 -- Special value used to indicate no line number 171 172 type Physical_Line_Number is range 1 .. Int'Last; 173 for Physical_Line_Number'Size use 32; 174 -- Line number type, used for storing physical line numbers (i.e. line 175 -- numbers in the physical file being compiled, unaffected by the presence 176 -- of source reference pragmas). 177 178 type Column_Number is range 0 .. 32767; 179 for Column_Number'Size use 16; 180 -- Column number (assume that 2**15 - 1 is large enough). The range for 181 -- this type is used to compute Hostparm.Max_Line_Length. See also the 182 -- processing for -gnatyM in Stylesw). 183 184 No_Column_Number : constant Column_Number := 0; 185 -- Special value used to indicate no column number 186 187 Source_Align : constant := 2 ** 12; 188 -- Alignment requirement for source buffers (by keeping source buffers 189 -- aligned, we can optimize the implementation of Get_Source_File_Index. 190 -- See this routine in Sinput for details. 191 192 subtype Source_Buffer is Text_Buffer; 193 -- Type used to store text of a source file. The buffer for the main 194 -- source (the source specified on the command line) has a lower bound 195 -- starting at zero. Subsequent subsidiary sources have lower bounds 196 -- which are one greater than the previous upper bound, rounded up to 197 -- a multiple of Source_Align. 198 199 type Source_Buffer_Ptr_Var is access all Source_Buffer; 200 type Source_Buffer_Ptr is access constant Source_Buffer; 201 -- Pointer to source buffer. Source_Buffer_Ptr_Var is used for allocation 202 -- and deallocation; Source_Buffer_Ptr is used for all other uses of source 203 -- buffers. 204 205 function Null_Source_Buffer_Ptr (X : Source_Buffer_Ptr) return Boolean; 206 -- True if X = null 207 208 function Source_Buffer_Ptr_Equal (X, Y : Source_Buffer_Ptr) return Boolean 209 renames "="; 210 -- Squirrel away the predefined "=", for use in Null_Source_Buffer_Ptr. 211 -- Do not call this elsewhere. 212 213 function "=" (X, Y : Source_Buffer_Ptr) return Boolean is abstract; 214 -- Make "=" abstract. Note that this makes "/=" abstract as well. This is a 215 -- vestige of the zero-origin array indexing we used to use, where "=" is 216 -- always wrong (including the one in Null_Source_Buffer_Ptr). We keep this 217 -- just because we never need to compare Source_Buffer_Ptrs other than to 218 -- null. 219 220 subtype Source_Ptr is Text_Ptr; 221 -- Type used to represent a source location, which is a subscript of a 222 -- character in the source buffer. As noted above, different source buffers 223 -- have different ranges, so it is possible to tell from a Source_Ptr value 224 -- which source it refers to. Note that negative numbers are allowed to 225 -- accommodate the following special values. 226 227 No_Location : constant Source_Ptr := -1; 228 -- Value used to indicate no source position set in a node. A test for a 229 -- Source_Ptr value being > No_Location is the approved way to test for a 230 -- standard value that does not include No_Location or any of the following 231 -- special definitions. One important use of No_Location is to label 232 -- generated nodes that we don't want the debugger to see in normal mode 233 -- (very often we conditionalize so that we set No_Location in normal mode 234 -- and the corresponding source line in -gnatD mode). 235 236 Standard_Location : constant Source_Ptr := -2; 237 -- Used for all nodes in the representation of package Standard other than 238 -- nodes representing the contents of Standard.ASCII. Note that testing for 239 -- a value being <= Standard_Location tests for both Standard_Location and 240 -- for Standard_ASCII_Location. 241 242 Standard_ASCII_Location : constant Source_Ptr := -3; 243 -- Used for all nodes in the presentation of package Standard.ASCII 244 245 System_Location : constant Source_Ptr := -4; 246 -- Used to identify locations of pragmas scanned by Targparm, where we know 247 -- the location is in System, but we don't know exactly what line. 248 249 First_Source_Ptr : constant Source_Ptr := 0; 250 -- Starting source pointer index value for first source program 251 252 ------------------------------------- 253 -- Range Definitions for Tree Data -- 254 ------------------------------------- 255 256 -- The tree has fields that can hold any of the following types: 257 258 -- Pointers to other tree nodes (type Node_Id) 259 -- List pointers (type List_Id) 260 -- Element list pointers (type Elist_Id) 261 -- Names (type Name_Id) 262 -- Strings (type String_Id) 263 -- Universal integers (type Uint) 264 -- Universal reals (type Ureal) 265 266 -- These types are represented as integer indices into various tables. 267 -- However, they should be treated as private, except in a few documented 268 -- cases. In particular it is never appropriate to perform arithmetic 269 -- operations using these types. 270 271 -- In most contexts, the strongly typed interface determines which of these 272 -- types is present. However, there are some situations (involving untyped 273 -- traversals of the tree), where it is convenient to be easily able to 274 -- distinguish these values. The underlying representation in all cases is 275 -- an integer type Union_Id, and we ensure that the range of the various 276 -- possible values for each of the above types is disjoint so that this 277 -- distinction is possible. 278 279 -- Note: it is also helpful for debugging purposes to make these ranges 280 -- distinct. If a bug leads to misidentification of a value, then it will 281 -- typically result in an out of range value and a Constraint_Error. 282 283 type Union_Id is new Int; 284 -- The type in the tree for a union of possible ID values 285 286 List_Low_Bound : constant := -100_000_000; 287 -- The List_Id values are subscripts into an array of list headers which 288 -- has List_Low_Bound as its lower bound. This value is chosen so that all 289 -- List_Id values are negative, and the value zero is in the range of both 290 -- List_Id and Node_Id values (see further description below). 291 292 List_High_Bound : constant := 0; 293 -- Maximum List_Id subscript value. This allows up to 100 million list Id 294 -- values, which is in practice infinite, and there is no need to check the 295 -- range. The range overlaps the node range by one element (with value 296 -- zero), which is used both for the Empty node, and for indicating no 297 -- list. The fact that the same value is used is convenient because it 298 -- means that the default value of Empty applies to both nodes and lists, 299 -- and also is more efficient to test for. 300 301 Node_Low_Bound : constant := 0; 302 -- The tree Id values start at zero, because we use zero for Empty (to 303 -- allow a zero test for Empty). Actual tree node subscripts start at 0 304 -- since Empty is a legitimate node value. 305 306 Node_High_Bound : constant := 099_999_999; 307 -- Maximum number of nodes that can be allocated is 100 million, which 308 -- is in practice infinite, and there is no need to check the range. 309 310 Elist_Low_Bound : constant := 100_000_000; 311 -- The Elist_Id values are subscripts into an array of elist headers which 312 -- has Elist_Low_Bound as its lower bound. 313 314 Elist_High_Bound : constant := 199_999_999; 315 -- Maximum Elist_Id subscript value. This allows up to 100 million Elists, 316 -- which is in practice infinite and there is no need to check the range. 317 318 Elmt_Low_Bound : constant := 200_000_000; 319 -- Low bound of element Id values. The use of these values is internal to 320 -- the Elists package, but the definition of the range is included here 321 -- since it must be disjoint from other Id values. The Elmt_Id values are 322 -- subscripts into an array of list elements which has this as lower bound. 323 324 Elmt_High_Bound : constant := 299_999_999; 325 -- Upper bound of Elmt_Id values. This allows up to 100 million element 326 -- list members, which is in practice infinite (no range check needed). 327 328 Names_Low_Bound : constant := 300_000_000; 329 -- Low bound for name Id values 330 331 Names_High_Bound : constant := 399_999_999; 332 -- Maximum number of names that can be allocated is 100 million, which is 333 -- in practice infinite and there is no need to check the range. 334 335 Strings_Low_Bound : constant := 400_000_000; 336 -- Low bound for string Id values 337 338 Strings_High_Bound : constant := 499_999_999; 339 -- Maximum number of strings that can be allocated is 100 million, which 340 -- is in practice infinite and there is no need to check the range. 341 342 Ureal_Low_Bound : constant := 500_000_000; 343 -- Low bound for Ureal values 344 345 Ureal_High_Bound : constant := 599_999_999; 346 -- Maximum number of Ureal values stored is 100_000_000 which is in 347 -- practice infinite so that no check is required. 348 349 Uint_Low_Bound : constant := 600_000_000; 350 -- Low bound for Uint values 351 352 Uint_Table_Start : constant := 2_000_000_000; 353 -- Location where table entries for universal integers start (see 354 -- Uintp spec for details of the representation of Uint values). 355 356 Uint_High_Bound : constant := 2_099_999_999; 357 -- The range of Uint values is very large, since a substantial part 358 -- of this range is used to store direct values, see Uintp for details. 359 360 -- The following subtype definitions are used to provide convenient names 361 -- for membership tests on Int values to see what data type range they 362 -- lie in. Such tests appear only in the lowest level packages. 363 364 subtype List_Range is Union_Id 365 range List_Low_Bound .. List_High_Bound; 366 367 subtype Node_Range is Union_Id 368 range Node_Low_Bound .. Node_High_Bound; 369 370 subtype Elist_Range is Union_Id 371 range Elist_Low_Bound .. Elist_High_Bound; 372 373 subtype Elmt_Range is Union_Id 374 range Elmt_Low_Bound .. Elmt_High_Bound; 375 376 subtype Names_Range is Union_Id 377 range Names_Low_Bound .. Names_High_Bound; 378 379 subtype Strings_Range is Union_Id 380 range Strings_Low_Bound .. Strings_High_Bound; 381 382 subtype Uint_Range is Union_Id 383 range Uint_Low_Bound .. Uint_High_Bound; 384 385 subtype Ureal_Range is Union_Id 386 range Ureal_Low_Bound .. Ureal_High_Bound; 387 388 ----------------------------- 389 -- Types for Atree Package -- 390 ----------------------------- 391 392 -- Node_Id values are used to identify nodes in the tree. They are 393 -- subscripts into the Nodes table declared in package Atree. Note that 394 -- the special values Empty and Error are subscripts into this table. 395 -- See package Atree for further details. 396 397 type Node_Id is range Node_Low_Bound .. Node_High_Bound; 398 -- Type used to identify nodes in the tree 399 400 subtype Entity_Id is Node_Id; 401 -- A synonym for node types, used in the Einfo package to refer to nodes 402 -- that are entities (i.e. nodes with an Nkind of N_Defining_xxx). All such 403 -- nodes are extended nodes and these are the only extended nodes, so that 404 -- in practice entity and extended nodes are synonymous. 405 406 subtype Node_Or_Entity_Id is Node_Id; 407 -- A synonym for node types, used in cases where a given value may be used 408 -- to represent either a node or an entity. We like to minimize such uses 409 -- for obvious reasons of logical type consistency, but where such uses 410 -- occur, they should be documented by use of this type. 411 412 Empty : constant Node_Id := Node_Low_Bound; 413 -- Used to indicate null node. A node is actually allocated with this 414 -- Id value, so that Nkind (Empty) = N_Empty. Note that Node_Low_Bound 415 -- is zero, so Empty = No_List = zero. 416 417 Empty_List_Or_Node : constant := 0; 418 -- This constant is used in situations (e.g. initializing empty fields) 419 -- where the value set will be used to represent either an empty node or 420 -- a non-existent list, depending on the context. 421 422 Error : constant Node_Id := Node_Low_Bound + 1; 423 -- Used to indicate an error in the source program. A node is actually 424 -- allocated with this Id value, so that Nkind (Error) = N_Error. 425 426 Empty_Or_Error : constant Node_Id := Error; 427 -- Since Empty and Error are the first two Node_Id values, the test for 428 -- N <= Empty_Or_Error tests to see if N is Empty or Error. This definition 429 -- provides convenient self-documentation for such tests. 430 431 First_Node_Id : constant Node_Id := Node_Low_Bound; 432 -- Subscript of first allocated node. Note that Empty and Error are both 433 -- allocated nodes, whose Nkind fields can be accessed without error. 434 435 ------------------------------ 436 -- Types for Nlists Package -- 437 ------------------------------ 438 439 -- List_Id values are used to identify node lists stored in the tree, so 440 -- that each node can be on at most one such list (see package Nlists for 441 -- further details). Note that the special value Error_List is a subscript 442 -- in this table, but the value No_List is *not* a valid subscript, and any 443 -- attempt to apply list operations to No_List will cause a (detected) 444 -- error. 445 446 type List_Id is range List_Low_Bound .. List_High_Bound; 447 -- Type used to identify a node list 448 449 No_List : constant List_Id := List_High_Bound; 450 -- Used to indicate absence of a list. Note that the value is zero, which 451 -- is the same as Empty, which is helpful in initializing nodes where a 452 -- value of zero can represent either an empty node or an empty list. 453 454 Error_List : constant List_Id := List_Low_Bound; 455 -- Used to indicate that there was an error in the source program in a 456 -- context which would normally require a list. This node appears to be 457 -- an empty list to the list operations (a null list is actually allocated 458 -- which has this Id value). 459 460 First_List_Id : constant List_Id := Error_List; 461 -- Subscript of first allocated list header 462 463 ------------------------------ 464 -- Types for Elists Package -- 465 ------------------------------ 466 467 -- Element list Id values are used to identify element lists stored outside 468 -- of the tree, allowing nodes to be members of more than one such list 469 -- (see package Elists for further details). 470 471 type Elist_Id is range Elist_Low_Bound .. Elist_High_Bound; 472 -- Type used to identify an element list (Elist header table subscript) 473 474 No_Elist : constant Elist_Id := Elist_Low_Bound; 475 -- Used to indicate absence of an element list. Note that this is not an 476 -- actual Elist header, so element list operations on this value are not 477 -- valid. 478 479 First_Elist_Id : constant Elist_Id := No_Elist + 1; 480 -- Subscript of first allocated Elist header 481 482 -- Element Id values are used to identify individual elements of an element 483 -- list (see package Elists for further details). 484 485 type Elmt_Id is range Elmt_Low_Bound .. Elmt_High_Bound; 486 -- Type used to identify an element list 487 488 No_Elmt : constant Elmt_Id := Elmt_Low_Bound; 489 -- Used to represent empty element 490 491 First_Elmt_Id : constant Elmt_Id := No_Elmt + 1; 492 -- Subscript of first allocated Elmt table entry 493 494 ------------------------------- 495 -- Types for Stringt Package -- 496 ------------------------------- 497 498 -- String_Id values are used to identify entries in the strings table. They 499 -- are subscripts into the Strings table defined in package Stringt. 500 501 type String_Id is range Strings_Low_Bound .. Strings_High_Bound; 502 -- Type used to identify entries in the strings table 503 504 No_String : constant String_Id := Strings_Low_Bound; 505 -- Used to indicate missing string Id. Note that the value zero is used 506 -- to indicate a missing data value for all the Int types in this section. 507 508 First_String_Id : constant String_Id := No_String + 1; 509 -- First subscript allocated in string table 510 511 ------------------------- 512 -- Character Code Type -- 513 ------------------------- 514 515 -- The type Char is used for character data internally in the compiler, but 516 -- character codes in the source are represented by the Char_Code type. 517 -- Each character literal in the source is interpreted as being one of the 518 -- 16#7FFF_FFFF# possible Wide_Wide_Character codes, and a unique Integer 519 -- value is assigned, corresponding to the UTF-32 value, which also 520 -- corresponds to the Pos value in the Wide_Wide_Character type, and also 521 -- corresponds to the Pos value in the Wide_Character and Character types 522 -- for values that are in appropriate range. String literals are similarly 523 -- interpreted as a sequence of such codes. 524 525 type Char_Code_Base is mod 2 ** 32; 526 for Char_Code_Base'Size use 32; 527 528 subtype Char_Code is Char_Code_Base range 0 .. 16#7FFF_FFFF#; 529 for Char_Code'Value_Size use 32; 530 for Char_Code'Object_Size use 32; 531 532 function Get_Char_Code (C : Character) return Char_Code; 533 pragma Inline (Get_Char_Code); 534 -- Function to obtain internal character code from source character. For 535 -- the moment, the internal character code is simply the Pos value of the 536 -- input source character, but we provide this interface for possible 537 -- later support of alternative character sets. 538 539 function In_Character_Range (C : Char_Code) return Boolean; 540 pragma Inline (In_Character_Range); 541 -- Determines if the given character code is in range of type Character, 542 -- and if so, returns True. If not, returns False. 543 544 function In_Wide_Character_Range (C : Char_Code) return Boolean; 545 pragma Inline (In_Wide_Character_Range); 546 -- Determines if the given character code is in range of the type 547 -- Wide_Character, and if so, returns True. If not, returns False. 548 549 function Get_Character (C : Char_Code) return Character; 550 pragma Inline (Get_Character); 551 -- For a character C that is in Character range (see above function), this 552 -- function returns the corresponding Character value. It is an error to 553 -- call Get_Character if C is not in Character range. 554 555 function Get_Wide_Character (C : Char_Code) return Wide_Character; 556 -- For a character C that is in Wide_Character range (see above function), 557 -- this function returns the corresponding Wide_Character value. It is an 558 -- error to call Get_Wide_Character if C is not in Wide_Character range. 559 560 --------------------------------------- 561 -- Types used for Library Management -- 562 --------------------------------------- 563 564 type Unit_Number_Type is new Int range -1 .. Int'Last; 565 -- Unit number. The main source is unit 0, and subsidiary sources have 566 -- non-zero numbers starting with 1. Unit numbers are used to index the 567 -- Units table in package Lib. 568 569 Main_Unit : constant Unit_Number_Type := 0; 570 -- Unit number value for main unit 571 572 No_Unit : constant Unit_Number_Type := -1; 573 -- Special value used to signal no unit 574 575 type Source_File_Index is new Int range -1 .. Int'Last; 576 -- Type used to index the source file table (see package Sinput) 577 578 No_Source_File : constant Source_File_Index := 0; 579 -- Value used to indicate no source file present 580 581 No_Access_To_Source_File : constant Source_File_Index := -1; 582 -- Value used to indicate a source file is present but unreadable 583 584 ----------------------------------- 585 -- Representation of Time Stamps -- 586 ----------------------------------- 587 588 -- All compiled units are marked with a time stamp which is derived from 589 -- the source file (we assume that the host system has the concept of a 590 -- file time stamp which is modified when a file is modified). These 591 -- time stamps are used to ensure consistency of the set of units that 592 -- constitutes a library. Time stamps are 14-character strings with 593 -- with the following format: 594 595 -- YYYYMMDDHHMMSS 596 597 -- YYYY year 598 -- MM month (2 digits 01-12) 599 -- DD day (2 digits 01-31) 600 -- HH hour (2 digits 00-23) 601 -- MM minutes (2 digits 00-59) 602 -- SS seconds (2 digits 00-59) 603 604 -- In the case of Unix systems (and other systems which keep the time in 605 -- GMT), the time stamp is the GMT time of the file, not the local time. 606 -- This solves problems in using libraries across networks with clients 607 -- spread across multiple time-zones. 608 609 Time_Stamp_Length : constant := 14; 610 -- Length of time stamp value 611 612 subtype Time_Stamp_Index is Natural range 1 .. Time_Stamp_Length; 613 type Time_Stamp_Type is new String (Time_Stamp_Index); 614 -- Type used to represent time stamp 615 616 Empty_Time_Stamp : constant Time_Stamp_Type := (others => ' '); 617 -- Value representing an empty or missing time stamp. Looks less than any 618 -- real time stamp if two time stamps are compared. Note that although this 619 -- is not private, clients should not rely on the exact way in which this 620 -- string is represented, and instead should use the subprograms below. 621 622 Dummy_Time_Stamp : constant Time_Stamp_Type := (others => '0'); 623 -- This is used for dummy time stamp values used in the D lines for 624 -- non-existent files, and is intended to be an impossible value. 625 626 function "=" (Left, Right : Time_Stamp_Type) return Boolean; 627 function "<=" (Left, Right : Time_Stamp_Type) return Boolean; 628 function ">=" (Left, Right : Time_Stamp_Type) return Boolean; 629 function "<" (Left, Right : Time_Stamp_Type) return Boolean; 630 function ">" (Left, Right : Time_Stamp_Type) return Boolean; 631 -- Comparison functions on time stamps. Note that two time stamps are 632 -- defined as being equal if they have the same day/month/year and the 633 -- hour/minutes/seconds values are within 2 seconds of one another. This 634 -- deals with rounding effects in library file time stamps caused by 635 -- copying operations during installation. We have particularly noticed 636 -- that WinNT seems susceptible to such changes. 637 -- 638 -- Note: the Empty_Time_Stamp value looks equal to itself, and less than 639 -- any non-empty time stamp value. 640 641 procedure Split_Time_Stamp 642 (TS : Time_Stamp_Type; 643 Year : out Nat; 644 Month : out Nat; 645 Day : out Nat; 646 Hour : out Nat; 647 Minutes : out Nat; 648 Seconds : out Nat); 649 -- Given a time stamp, decompose it into its components 650 651 procedure Make_Time_Stamp 652 (Year : Nat; 653 Month : Nat; 654 Day : Nat; 655 Hour : Nat; 656 Minutes : Nat; 657 Seconds : Nat; 658 TS : out Time_Stamp_Type); 659 -- Given the components of a time stamp, initialize the value 660 661 ------------------------------------- 662 -- Types used for Check Management -- 663 ------------------------------------- 664 665 type Check_Id is new Nat; 666 -- Type used to represent a check id 667 668 No_Check_Id : constant := 0; 669 -- Check_Id value used to indicate no check 670 671 Access_Check : constant := 1; 672 Accessibility_Check : constant := 2; 673 Alignment_Check : constant := 3; 674 Allocation_Check : constant := 4; 675 Atomic_Synchronization : constant := 5; 676 Discriminant_Check : constant := 6; 677 Division_Check : constant := 7; 678 Duplicated_Tag_Check : constant := 8; 679 Elaboration_Check : constant := 9; 680 Index_Check : constant := 10; 681 Length_Check : constant := 11; 682 Overflow_Check : constant := 12; 683 Predicate_Check : constant := 13; 684 Range_Check : constant := 14; 685 Storage_Check : constant := 15; 686 Tag_Check : constant := 16; 687 Validity_Check : constant := 17; 688 Container_Checks : constant := 18; 689 Tampering_Check : constant := 19; 690 -- Values used to represent individual predefined checks (including the 691 -- setting of Atomic_Synchronization, which is implemented internally using 692 -- a "check" whose name is Atomic_Synchronization). 693 694 All_Checks : constant := 20; 695 -- Value used to represent All_Checks value 696 697 subtype Predefined_Check_Id is Check_Id range 1 .. All_Checks; 698 -- Subtype for predefined checks, including All_Checks 699 700 -- The following array contains an entry for each recognized check name 701 -- for pragma Suppress. It is used to represent current settings of scope 702 -- based suppress actions from pragma Suppress or command line settings. 703 704 -- Note: when Suppress_Array (All_Checks) is True, then generally all other 705 -- specific check entries are set True, except for the Elaboration_Check 706 -- entry which is set only if an explicit Suppress for this check is given. 707 -- The reason for this non-uniformity is that we do not want All_Checks to 708 -- suppress elaboration checking when using the static elaboration model. 709 -- We recognize only an explicit suppress of Elaboration_Check as a signal 710 -- that the static elaboration checking should skip a compile time check. 711 712 type Suppress_Array is array (Predefined_Check_Id) of Boolean; 713 pragma Pack (Suppress_Array); 714 715 -- To add a new check type to GNAT, the following steps are required: 716 717 -- 1. Add an entry to Snames spec for the new name 718 -- 2. Add an entry to the definition of Check_Id above 719 -- 3. Add a new function to Checks to handle the new check test 720 -- 4. Add a new Do_xxx_Check flag to Sinfo (if required) 721 -- 5. Add appropriate checks for the new test 722 723 -- The following provides precise details on the mode used to generate 724 -- code for intermediate operations in expressions for signed integer 725 -- arithmetic (and how to generate overflow checks if enabled). Note 726 -- that this only affects handling of intermediate results. The final 727 -- result must always fit within the target range, and if overflow 728 -- checking is enabled, the check on the final result is against this 729 -- target range. 730 731 type Overflow_Mode_Type is ( 732 Not_Set, 733 -- Dummy value used during initialization process to show that the 734 -- corresponding value has not yet been initialized. 735 736 Strict, 737 -- Operations are done in the base type of the subexpression. If 738 -- overflow checks are enabled, then the check is against the range 739 -- of this base type. 740 741 Minimized, 742 -- Where appropriate, intermediate arithmetic operations are performed 743 -- with an extended range, using Long_Long_Integer if necessary. If 744 -- overflow checking is enabled, then the check is against the range 745 -- of Long_Long_Integer. 746 747 Eliminated); 748 -- In this mode arbitrary precision arithmetic is used as needed to 749 -- ensure that it is impossible for intermediate arithmetic to cause an 750 -- overflow. In this mode, intermediate expressions are not affected by 751 -- the overflow checking mode, since overflows are eliminated. 752 753 subtype Minimized_Or_Eliminated is 754 Overflow_Mode_Type range Minimized .. Eliminated; 755 -- Define subtype so that clients don't need to know ordering. Note that 756 -- Overflow_Mode_Type is not marked as an ordered enumeration type. 757 758 -- The following structure captures the state of check suppression or 759 -- activation at a particular point in the program execution. 760 761 type Suppress_Record is record 762 Suppress : Suppress_Array; 763 -- Indicates suppression status of each possible check 764 765 Overflow_Mode_General : Overflow_Mode_Type; 766 -- This field indicates the mode for handling code generation and 767 -- overflow checking (if enabled) for intermediate expression values. 768 -- This applies to general expressions outside assertions. 769 770 Overflow_Mode_Assertions : Overflow_Mode_Type; 771 -- This field indicates the mode for handling code generation and 772 -- overflow checking (if enabled) for intermediate expression values. 773 -- This applies to any expression occuring inside assertions. 774 end record; 775 776 ----------------------------------- 777 -- Global Exception Declarations -- 778 ----------------------------------- 779 780 -- This section contains declarations of exceptions that are used 781 -- throughout the compiler or in other GNAT tools. 782 783 Unrecoverable_Error : exception; 784 -- This exception is raised to immediately terminate the compilation of the 785 -- current source program. Used in situations where things are bad enough 786 -- that it doesn't seem worth continuing (e.g. max errors reached, or a 787 -- required file is not found). Also raised when the compiler finds itself 788 -- in trouble after an error (see Comperr). 789 790 Terminate_Program : exception; 791 -- This exception is raised to immediately terminate the tool being 792 -- executed. Each tool where this exception may be raised must have a 793 -- single exception handler that contains only a null statement and that is 794 -- the last statement of the program. If needed, procedure Set_Exit_Status 795 -- is called with the appropriate exit status before raising 796 -- Terminate_Program. 797 798 --------------------------------- 799 -- Parameter Mechanism Control -- 800 --------------------------------- 801 802 -- Function and parameter entities have a field that records the passing 803 -- mechanism. See specification of Sem_Mech for full details. The following 804 -- subtype is used to represent values of this type: 805 806 subtype Mechanism_Type is Int range -2 .. Int'Last; 807 -- Type used to represent a mechanism value. This is a subtype rather than 808 -- a type to avoid some annoying processing problems with certain routines 809 -- in Einfo (processing them to create the corresponding C). The values in 810 -- the range -2 .. 0 are used to represent mechanism types declared as 811 -- named constants in the spec of Sem_Mech. Positive values are used for 812 -- the case of a pragma C_Pass_By_Copy that sets a threshold value for the 813 -- mechanism to be used. For example if pragma C_Pass_By_Copy (32) is given 814 -- then Default_C_Record_Mechanism is set to 32, and the meaning is to use 815 -- By_Reference if the size is greater than 32, and By_Copy otherwise. 816 817 ------------------------------ 818 -- Run-Time Exception Codes -- 819 ------------------------------ 820 821 -- When the code generator generates a run-time exception, it provides a 822 -- reason code which is one of the following. This reason code is used to 823 -- select the appropriate run-time routine to be called, determining both 824 -- the exception to be raised, and the message text to be added. 825 826 -- The prefix CE/PE/SE indicates the exception to be raised 827 -- CE = Constraint_Error 828 -- PE = Program_Error 829 -- SE = Storage_Error 830 831 -- The remaining part of the name indicates the message text to be added, 832 -- where all letters are lower case, and underscores are converted to 833 -- spaces (for example CE_Invalid_Data adds the text "invalid data"). 834 835 -- To add a new code, you need to do the following: 836 837 -- 1. Assign a new number to the reason. Do not renumber existing codes, 838 -- since this causes compatibility/bootstrap issues, so always add the 839 -- new code at the end of the list. 840 841 -- 2. Update the contents of the array Kind 842 843 -- 3. Modify the corresponding definitions in types.h, including the 844 -- definition of last_reason_code. 845 846 -- 4. Add the name of the routines in exp_ch11.Get_RT_Exception_Name 847 848 -- 5. Add a new routine in Ada.Exceptions with the appropriate call and 849 -- static string constant. Note that there is more than one version 850 -- of a-except.adb which must be modified. 851 852 -- Note on ordering of references. For the tables in Ada.Exceptions units, 853 -- usually the ordering does not matter, and we use the same ordering as 854 -- is used here. 855 856 type RT_Exception_Code is 857 (CE_Access_Check_Failed, -- 00 858 CE_Access_Parameter_Is_Null, -- 01 859 CE_Discriminant_Check_Failed, -- 02 860 CE_Divide_By_Zero, -- 03 861 CE_Explicit_Raise, -- 04 862 CE_Index_Check_Failed, -- 05 863 CE_Invalid_Data, -- 06 864 CE_Length_Check_Failed, -- 07 865 CE_Null_Exception_Id, -- 08 866 CE_Null_Not_Allowed, -- 09 867 868 CE_Overflow_Check_Failed, -- 10 869 CE_Partition_Check_Failed, -- 11 870 CE_Range_Check_Failed, -- 12 871 CE_Tag_Check_Failed, -- 13 872 PE_Access_Before_Elaboration, -- 14 873 PE_Accessibility_Check_Failed, -- 15 874 PE_Address_Of_Intrinsic, -- 16 875 PE_Aliased_Parameters, -- 17 876 PE_All_Guards_Closed, -- 18 877 PE_Bad_Predicated_Generic_Type, -- 19 878 879 PE_Current_Task_In_Entry_Body, -- 20 880 PE_Duplicated_Entry_Address, -- 21 881 PE_Explicit_Raise, -- 22 882 PE_Finalize_Raised_Exception, -- 23 883 PE_Implicit_Return, -- 24 884 PE_Misaligned_Address_Value, -- 25 885 PE_Missing_Return, -- 26 886 PE_Overlaid_Controlled_Object, -- 27 887 PE_Potentially_Blocking_Operation, -- 28 888 PE_Stubbed_Subprogram_Called, -- 29 889 890 PE_Unchecked_Union_Restriction, -- 30 891 PE_Non_Transportable_Actual, -- 31 892 SE_Empty_Storage_Pool, -- 32 893 SE_Explicit_Raise, -- 33 894 SE_Infinite_Recursion, -- 34 895 SE_Object_Too_Large, -- 35 896 PE_Stream_Operation_Not_Allowed, -- 36 897 PE_Build_In_Place_Mismatch); -- 37 898 899 Last_Reason_Code : constant := 900 RT_Exception_Code'Pos (RT_Exception_Code'Last); 901 -- Last reason code 902 903 type Reason_Kind is (CE_Reason, PE_Reason, SE_Reason); 904 -- Categorization of reason codes by exception raised 905 906 Rkind : constant array (RT_Exception_Code range <>) of Reason_Kind := 907 (CE_Access_Check_Failed => CE_Reason, 908 CE_Access_Parameter_Is_Null => CE_Reason, 909 CE_Discriminant_Check_Failed => CE_Reason, 910 CE_Divide_By_Zero => CE_Reason, 911 CE_Explicit_Raise => CE_Reason, 912 CE_Index_Check_Failed => CE_Reason, 913 CE_Invalid_Data => CE_Reason, 914 CE_Length_Check_Failed => CE_Reason, 915 CE_Null_Exception_Id => CE_Reason, 916 CE_Null_Not_Allowed => CE_Reason, 917 CE_Overflow_Check_Failed => CE_Reason, 918 CE_Partition_Check_Failed => CE_Reason, 919 CE_Range_Check_Failed => CE_Reason, 920 CE_Tag_Check_Failed => CE_Reason, 921 922 PE_Access_Before_Elaboration => PE_Reason, 923 PE_Accessibility_Check_Failed => PE_Reason, 924 PE_Address_Of_Intrinsic => PE_Reason, 925 PE_Aliased_Parameters => PE_Reason, 926 PE_All_Guards_Closed => PE_Reason, 927 PE_Bad_Predicated_Generic_Type => PE_Reason, 928 PE_Current_Task_In_Entry_Body => PE_Reason, 929 PE_Duplicated_Entry_Address => PE_Reason, 930 PE_Explicit_Raise => PE_Reason, 931 PE_Finalize_Raised_Exception => PE_Reason, 932 PE_Implicit_Return => PE_Reason, 933 PE_Misaligned_Address_Value => PE_Reason, 934 PE_Missing_Return => PE_Reason, 935 PE_Overlaid_Controlled_Object => PE_Reason, 936 PE_Potentially_Blocking_Operation => PE_Reason, 937 PE_Stubbed_Subprogram_Called => PE_Reason, 938 PE_Unchecked_Union_Restriction => PE_Reason, 939 PE_Non_Transportable_Actual => PE_Reason, 940 PE_Stream_Operation_Not_Allowed => PE_Reason, 941 PE_Build_In_Place_Mismatch => PE_Reason, 942 943 SE_Empty_Storage_Pool => SE_Reason, 944 SE_Explicit_Raise => SE_Reason, 945 SE_Infinite_Recursion => SE_Reason, 946 SE_Object_Too_Large => SE_Reason); 947 948end Types; 949