1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- R E S T R I C T -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2021, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26-- This package deals with the implementation of the Restrictions pragma 27 28with Aspects; use Aspects; 29with Namet; use Namet; 30with Rident; use Rident; 31with Snames; use Snames; 32with Table; 33with Types; use Types; 34with Uintp; use Uintp; 35 36package Restrict is 37 38 Restrictions : Restrictions_Info := No_Restrictions; 39 -- This variable records restrictions found in any units in the main 40 -- extended unit, and in the case of restrictions checked for partition 41 -- consistency, restrictions found in any with'ed units, parent specs 42 -- etc., since we may as well check as much as we can at compile time. 43 -- These variables should not be referenced directly by clients. Instead 44 -- use Check_Restriction to record a violation of a restriction, and 45 -- Restriction_Active to test if a given restriction is active. 46 47 Restrictions_Loc : array (All_Restrictions) of Source_Ptr := 48 (others => No_Location); 49 -- Locations of Restrictions pragmas for error message purposes. 50 -- Valid only if corresponding entry in Restrictions is set. A value 51 -- of No_Location is used for implicit restrictions set by another 52 -- pragma, and a value of System_Location is used for restrictions 53 -- set from package Standard by the processing in Targparm. 54 55 Restriction_Profile_Name : array (All_Restrictions) of Profile_Name; 56 -- Entries in this array are valid only if the corresponding restriction in 57 -- Restrictions is set. The value is the corresponding profile name if the 58 -- restriction was set by a Profile or Profile_Warnings pragma. The value 59 -- is No_Profile in all other cases. 60 61 Main_Restrictions : Restrictions_Info := No_Restrictions; 62 -- This variable records only restrictions found in any units of the 63 -- main extended unit. These are the variables used for ali file output, 64 -- since we want the binder to be able to accurately diagnose inter-unit 65 -- restriction violations. 66 67 Restriction_Warnings : Rident.Restriction_Flags := (others => False); 68 -- If one of these flags is set, then it means that violation of the 69 -- corresponding restriction results only in a warning message, not 70 -- in an error message, and the restriction is not otherwise enforced. 71 -- Note that the flags in Restrictions are set to indicate that the 72 -- restriction is set in this case, but Main_Restrictions is never 73 -- set if Restriction_Warnings is set, so this does not look like a 74 -- restriction to the binder. 75 76 -- The following declarations establish a mapping between restriction 77 -- identifiers, and the names of corresponding restricted library units. 78 79 type Unit_Entry is record 80 Res_Id : Restriction_Id; 81 Filenm : String (1 .. 8); 82 end record; 83 84 Unit_Array : constant array (Positive range <>) of Unit_Entry := ( 85 (No_Asynchronous_Control, "a-astaco"), 86 (No_Calendar, "a-calend"), 87 (No_Calendar, "calendar"), 88 (No_Delay, "a-calend"), 89 (No_Delay, "calendar"), 90 (No_Dynamic_Priorities, "a-dynpri"), 91 (No_Finalization, "a-finali"), 92 (No_IO, "a-direct"), 93 (No_IO, "a-direio"), 94 (No_IO, "directio"), 95 (No_IO, "a-sequio"), 96 (No_IO, "sequenio"), 97 (No_IO, "a-ststio"), 98 (No_IO, "a-textio"), 99 (No_IO, "text_io "), 100 (No_IO, "a-witeio"), 101 (No_Task_Attributes_Package, "a-tasatt"), 102 (No_Unchecked_Conversion, "a-unccon"), 103 (No_Unchecked_Conversion, "unchconv"), 104 (No_Unchecked_Deallocation, "a-uncdea"), 105 (No_Unchecked_Deallocation, "unchdeal")); 106 107 -- The following map has True for all GNAT-defined Restrictions. It is used 108 -- to implement pragma Restrictions (No_Implementation_Restrictions) (which 109 -- is why this restriction itself is excluded from the list). 110 111 Implementation_Restriction : constant array (All_Restrictions) of Boolean := 112 (Simple_Barriers => True, 113 No_Calendar => True, 114 No_Default_Initialization => True, 115 No_Direct_Boolean_Operators => True, 116 No_Dispatching_Calls => True, 117 No_Dynamic_Accessibility_Checks => True, 118 No_Dynamic_Attachment => True, 119 No_Elaboration_Code => True, 120 No_Enumeration_Maps => True, 121 No_Entry_Calls_In_Elaboration_Code => True, 122 No_Entry_Queue => True, 123 No_Exception_Handlers => True, 124 No_Exception_Propagation => True, 125 No_Exception_Registration => True, 126 No_Finalization => True, 127 No_Fixed_IO => True, 128 No_Implementation_Attributes => True, 129 No_Implementation_Pragmas => True, 130 No_Implicit_Conditionals => True, 131 No_Implicit_Aliasing => True, 132 No_Implicit_Dynamic_Code => True, 133 No_Implicit_Loops => True, 134 No_Initialize_Scalars => True, 135 No_Local_Protected_Objects => True, 136 No_Long_Long_Integers => True, 137 No_Multiple_Elaboration => True, 138 No_Protected_Type_Allocators => True, 139 No_Relative_Delay => True, 140 No_Requeue_Statements => True, 141 No_Secondary_Stack => True, 142 No_Select_Statements => True, 143 No_Standard_Storage_Pools => True, 144 No_Stream_Optimizations => True, 145 No_Streams => True, 146 No_Task_Attributes_Package => True, 147 No_Task_Termination => True, 148 No_Tasking => True, 149 No_Wide_Characters => True, 150 Static_Priorities => True, 151 Static_Storage_Size => True, 152 Pure_Barriers => True, 153 SPARK_05 => True, 154 others => False); 155 156 -------------------------- 157 -- No_Dependences Table -- 158 -------------------------- 159 160 -- The following table records entries made by Restrictions pragmas 161 -- that specify a parameter for No_Dependence. Each such pragma makes 162 -- an entry in this table. 163 164 -- Note: we have chosen to implement this restriction in the "syntactic" 165 -- form, where we do not check that the named package is a language defined 166 -- package, but instead we allow arbitrary package names. The discussion of 167 -- this issue is not complete in the ARG, but the sense seems to be leaning 168 -- in this direction, which makes more sense to us, since it is much more 169 -- useful, and much easier to implement. 170 171 type ND_Entry is record 172 Unit : Node_Id; 173 -- The unit parameter from the No_Dependence pragma 174 175 Warn : Boolean; 176 -- True if from Restriction_Warnings, False if from Restrictions 177 178 Profile : Profile_Name; 179 -- Set to name of profile from which No_Dependence entry came, or to 180 -- No_Profile if a pragma Restriction set the No_Dependence entry. 181 end record; 182 183 package No_Dependences is new Table.Table ( 184 Table_Component_Type => ND_Entry, 185 Table_Index_Type => Int, 186 Table_Low_Bound => 0, 187 Table_Initial => 200, 188 Table_Increment => 200, 189 Table_Name => "Name_No_Dependences"); 190 191 ---------------------------- 192 -- No_Use_Of_Entity Table -- 193 ---------------------------- 194 195 -- The following table records entries made by Restrictions pragmas 196 -- that specify a parameter for No_Use_Of_Entity. Each such pragma makes 197 -- an entry in this table. 198 199 -- Note: we have chosen to implement this restriction in the "syntactic" 200 -- form, where we allow arbitrary fully qualified names to be specified. 201 202 type NE_Entry is record 203 Entity : Node_Id; 204 -- The entity parameter from the No_Use_Of_Entity pragma. This is in 205 -- the form of a selected component, since that is the way the parser 206 -- processes it, and we don't further analyze it. 207 208 Warn : Boolean; 209 -- True if from Restriction_Warnings, False if from Restrictions 210 211 Profile : Profile_Name; 212 -- Set to name of profile from which No_Use_Of_Entity entry came, or to 213 -- No_Profile if a pragma Restriction set the No_Use_Of_Entity entry. 214 end record; 215 216 package No_Use_Of_Entity is new Table.Table ( 217 Table_Component_Type => NE_Entry, 218 Table_Index_Type => Int, 219 Table_Low_Bound => 0, 220 Table_Initial => 200, 221 Table_Increment => 200, 222 Table_Name => "Name_No_Use_Of_Entity"); 223 224 -- Note that in addition to making an entry in this table, we also set the 225 -- Boolean2 flag of the Name_Table entry for the simple name of the entity. 226 -- This is used to avoid most useless searches of this table. 227 228 ----------------- 229 -- Subprograms -- 230 ----------------- 231 232 -- Note: several of these subprograms can generate error messages (e.g. 233 -- Check_Restriction). These routines should be called in the analyzer 234 -- rather than the expander, so that the associated error messages are 235 -- correctly generated in semantics only (-gnatc) mode. 236 237 function Abort_Allowed return Boolean; 238 pragma Inline (Abort_Allowed); 239 -- Tests to see if abort is allowed by the current restrictions settings. 240 -- For abort to be allowed, either No_Abort_Statements must be False, 241 -- or Max_Asynchronous_Select_Nesting must be non-zero. 242 243 procedure Check_Compiler_Unit (Feature : String; N : Node_Id); 244 -- If unit N is in a unit that has a pragma Compiler_Unit_Warning, then 245 -- a message is posted on node N noting use of the given feature is not 246 -- permitted in the compiler (bootstrap considerations). 247 248 procedure Check_Compiler_Unit (Feature : String; Loc : Source_Ptr); 249 -- If unit N is in a unit that has a pragma Compiler_Unit_Warning, then a 250 -- message is posted at location Loc noting use of the given feature is not 251 -- permitted in the compiler (bootstrap considerations). 252 253 procedure Check_Restricted_Unit (U : Unit_Name_Type; N : Node_Id); 254 -- Checks if loading of unit U is prohibited by the setting of some 255 -- restriction (e.g. No_IO restricts the loading of unit Ada.Text_IO). 256 -- If a restriction exists post error message at the given node. 257 258 procedure Check_Restriction 259 (Msg_Issued : out Boolean; 260 R : Restriction_Id; 261 N : Node_Id; 262 V : Uint := Uint_Minus_1); 263 -- Checks that the given restriction is not set, and if it is set, an 264 -- appropriate message is posted on the given node, in which case 265 -- Msg_Issued is set to True (and False otherwise). Also records the 266 -- violation in the appropriate internal arrays. Note that it is mandatory 267 -- to always use this routine to check if a restriction is violated. Such 268 -- checks must never be done directly by the caller, since otherwise 269 -- violations in the absence of restrictions are not properly recorded. The 270 -- value of V is relevant only for parameter restrictions, and in this case 271 -- indicates the exact count for the violation. If the exact count is not 272 -- known, V is left at its default of -1 which indicates an unknown count. 273 274 procedure Check_Restriction 275 (R : Restriction_Id; 276 N : Node_Id; 277 V : Uint := Uint_Minus_1); 278 -- Wrapper on Check_Restriction with Msg_Issued, with the out-parameter 279 -- being ignored here. 280 281 procedure Check_Restriction_No_Dependence (U : Node_Id; Err : Node_Id); 282 -- Called when a dependence on a unit is created (either implicitly, or by 283 -- an explicit WITH clause). U is a node for the unit involved, and Err is 284 -- the node to which an error will be attached if necessary. 285 286 procedure Check_Restriction_No_Specification_Of_Aspect (N : Node_Id); 287 -- N is the node id for an N_Aspect_Specification, an N_Pragma, or an 288 -- N_Attribute_Definition_Clause. An error message (warning) will be issued 289 -- if a restriction (warning) was previously set for this aspect using 290 -- Set_No_Specification_Of_Aspect. 291 292 procedure Check_Restriction_No_Use_Of_Attribute (N : Node_Id); 293 -- N denotes an attribute definition clause or an attribute reference. An 294 -- error message (warning) will be issued if a restriction (warning) was 295 -- previously set for this attribute using Set_No_Use_Of_Attribute. 296 297 procedure Check_Restriction_No_Use_Of_Entity (N : Node_Id); 298 -- N is the node id for an entity reference. An error message (warning) 299 -- will be issued if a restriction (warning) was previously set for this 300 -- entity name using Set_No_Use_Of_Entity. 301 302 procedure Check_Restriction_No_Use_Of_Pragma (N : Node_Id); 303 -- N is the node of a pragma. An error message (warning) will be issued 304 -- if a restriction (warning) was previously set for this pragma using 305 -- Set_No_Use_Of_Pragma. 306 307 procedure Check_Elaboration_Code_Allowed (N : Node_Id); 308 -- Tests to see if elaboration code is allowed by the current restrictions 309 -- settings. This function is called by Gigi when it needs to define an 310 -- elaboration routine. If elaboration code is not allowed, an error 311 -- message is posted on the node given as argument. 312 313 -- WARNING: There is a matching C declaration of this subprogram in fe.h 314 315 procedure Check_No_Implicit_Aliasing (Obj : Node_Id); 316 -- Obj is a node for which Is_Aliased_View is True, which is being used in 317 -- a context (e.g. 'Access) where no implicit aliasing is allowed if the 318 -- restriction No_Implicit_Aliasing is set. This procedure checks for the 319 -- case where the restriction is active and Obj does not meet the required 320 -- rules for avoiding implicit aliases, and issues a restriction message. 321 322 procedure Check_Implicit_Dynamic_Code_Allowed (N : Node_Id); 323 -- Tests to see if dynamic code generation (dynamically generated 324 -- trampolines, in particular) is allowed by the current restrictions 325 -- settings. This function is called by Gigi when it needs to generate code 326 -- that generates a trampoline. If not allowed, an error message is posted 327 -- on the node given as argument. 328 329 -- WARNING: There is a matching C declaration of this subprogram in fe.h 330 331 procedure Check_No_Implicit_Heap_Alloc (N : Node_Id); 332 -- Equivalent to Check_Restriction (No_Implicit_Heap_Allocations, N). 333 -- Provided for easy use by back end, which has to check this restriction. 334 335 -- WARNING: There is a matching C declaration of this subprogram in fe.h 336 337 procedure Check_No_Implicit_Protected_Alloc (N : Node_Id); 338 -- Equivalent to: 339 -- Check_Restriction (No_Implicit_Protected_Object_Allocations, N) 340 -- Provided for easy use by back end, which has to check this restriction. 341 342 -- WARNING: There is a matching C declaration of this subprogram in fe.h 343 344 procedure Check_No_Implicit_Task_Alloc (N : Node_Id); 345 -- Equivalent to Check_Restriction (No_Implicit_Task_Allocations, N). 346 -- Provided for easy use by back end, which has to check this restriction. 347 348 -- WARNING: There is a matching C declaration of this subprogram in fe.h 349 350 procedure Check_Obsolescent_2005_Entity (E : Entity_Id; N : Node_Id); 351 -- This routine checks if the entity E is one of the obsolescent entries 352 -- in Ada.Characters.Handling in Ada 2005 and No_Obsolescent_Features 353 -- restriction is active. If so an appropriate message is given. N is 354 -- the node on which the message is to be placed. It's a bit kludgy to 355 -- have this highly specialized routine rather than some wonderful general 356 -- mechanism (e.g. a special pragma) to handle this case, but there are 357 -- only six cases, and it is not worth the effort to do something general. 358 359 procedure Check_Wide_Character_Restriction (E : Entity_Id; N : Node_Id); 360 -- This procedure checks if the No_Wide_Character restriction is active, 361 -- and if so, if N Comes_From_Source, and the root type of E is one of 362 -- [Wide_]Wide_Character or [Wide_]Wide_String, then the restriction 363 -- violation is recorded, and an appropriate message given. 364 365 function Get_Restriction_Id 366 (N : Name_Id) return Restriction_Id; 367 -- Given an identifier name, determines if it is a valid restriction 368 -- identifier, and if so returns the corresponding Restriction_Id value, 369 -- otherwise returns Not_A_Restriction_Id. 370 371 function OK_No_Dependence_Unit_Name (N : Node_Id) return Boolean; 372 -- Used in checking No_Dependence argument of pragma Restrictions or 373 -- pragma Restrictions_Warning, or attribute Restriction_Set. Returns 374 -- True if N has the proper form for a unit name, False otherwise. 375 376 function OK_No_Use_Of_Entity_Name (N : Node_Id) return Boolean; 377 -- Used in checking No_Use_Of_Entity argument of pragma Restrictions or 378 -- pragma Restrictions_Warning, or attribute Restriction_Set. Returns 379 -- True if N has the proper form for an entity name, False otherwise. 380 381 function No_Dynamic_Accessibility_Checks_Enabled 382 (N : Node_Id) return Boolean; 383 -- Test to see if the current restrictions settings specify that 384 -- No_Dynamic_Accessibility_Checks is activated. 385 386 -- N is currently unused, but is reserved for future use and debugging 387 -- purposes to provide more context on a node for which an accessibility 388 -- check is being performed or generated (e.g. is N in a predefined unit). 389 390 function No_Exception_Handlers_Set return Boolean; 391 -- Test to see if current restrictions settings specify that no exception 392 -- handlers are present. This function is called by Gigi when it needs to 393 -- expand an AT END clean up identifier with no exception handler. True 394 -- will be returned if the configurable run-time is activated, and either 395 -- of the restrictions No_Exception_Handlers or No_Exception_Propagation is 396 -- set. In the latter case, the source may contain handlers but they either 397 -- get converted using the local goto transformation or deleted. 398 399 -- WARNING: There is a matching C declaration of this subprogram in fe.h 400 401 function No_Exception_Propagation_Active return Boolean; 402 -- Test to see if current restrictions settings specify that no 403 -- exception propagation is activated. 404 405 -- WARNING: There is a matching C declaration of this subprogram in fe.h 406 407 function Process_Restriction_Synonyms (N : Node_Id) return Name_Id; 408 -- Id is a node whose Chars field contains the name of a restriction. 409 -- If it is one of synonyms that we allow for historical purposes (for 410 -- list see System.Rident), then the proper official name is returned. 411 412 function Restriction_Active (R : All_Restrictions) return Boolean; 413 pragma Inline (Restriction_Active); 414 -- Determines if a given restriction is active. This call should only be 415 -- used where the compiled code depends on whether the restriction is 416 -- active. Always use Check_Restriction to record a violation. Note that 417 -- this returns False if we only have a Restriction_Warnings set, since 418 -- restriction warnings should never affect generated code. If you want 419 -- to know if a call to Check_Restriction is needed then use the function 420 -- Restriction_Check_Required instead. 421 422 function Restriction_Check_Required (R : All_Restrictions) return Boolean; 423 pragma Inline (Restriction_Check_Required); 424 -- Determines if either a Restriction_Warnings or Restrictions pragma has 425 -- been given for the specified restriction. If true, then a subsequent 426 -- call to Check_Restriction is required if the restriction is violated. 427 -- This must not be used to guard code generation that depends on whether 428 -- a restriction is active (see Restriction_Active above). Typically it 429 -- is used to avoid complex code to determine if a restriction is violated, 430 -- executing this code only if needed. 431 432 function Restricted_Profile return Boolean; 433 -- Tests if set of restrictions corresponding to Restricted_Tasking profile 434 -- is currently in effect (set by pragma Profile, or by an appropriate set 435 -- of individual Restrictions pragmas). Returns True only if all the 436 -- required restrictions are set. 437 438 procedure Set_Global_No_Tasking; 439 -- Used in call from Sem_Prag when restriction No_Tasking is set in the 440 -- run-time package System or in a configuration pragmas file. 441 442 procedure Set_Profile_Restrictions 443 (P : Profile_Name; 444 N : Node_Id; 445 Warn : Boolean); 446 -- Sets the set of restrictions associated with the given profile name. N 447 -- is the node of the construct to which error messages are to be attached 448 -- as required. Warn is set True for the case of Profile_Warnings where the 449 -- restrictions are set as warnings rather than legality requirements, and 450 -- is also True for Profile if the Treat_Restrictions_As_Warnings flag is 451 -- set. It is false for Profile if this flag is not set. 452 453 procedure Set_Restriction 454 (R : All_Boolean_Restrictions; 455 N : Node_Id); 456 -- N is a node (typically a pragma node) that has the effect of setting 457 -- Boolean restriction R. The restriction is set in Restrictions, and 458 -- also in Main_Restrictions if this is the main unit. 459 460 procedure Set_Restriction 461 (R : All_Parameter_Restrictions; 462 N : Node_Id; 463 V : Integer); 464 -- Similar to the above, except that this is used for the case of a 465 -- parameter restriction, and the corresponding value V is given. 466 467 procedure Set_Restriction 468 (R : All_Restrictions; 469 N : Node_Id; 470 Warn : Boolean; 471 V : Integer := Integer'First); 472 -- Same as above two, except also takes care of setting the 473 -- Restriction_Warnings flag. V is ignored for Boolean 474 -- restrictions. 475 -- 476 -- If this is the first time we've seen this restriction, the warning flag 477 -- is set to Warn. If this is a second or subsequent time, Warn = False 478 -- wins; that is, errors always trump warnings. In that case, the warning 479 -- flag can be set to False, but never to True. 480 481 procedure Set_Restriction_No_Dependence 482 (Unit : Node_Id; 483 Warn : Boolean; 484 Profile : Profile_Name := No_Profile); 485 -- Sets given No_Dependence restriction in table if not there already. Warn 486 -- is True if from Restriction_Warnings, or for Restrictions if the flag 487 -- Treat_Restrictions_As_Warnings is set. False if from Restrictions and 488 -- this flag is not set. Profile is set to a non-default value if the 489 -- No_Dependence restriction comes from a Profile pragma. 490 491 procedure Set_Restriction_No_Specification_Of_Aspect 492 (N : Node_Id; 493 Warn : Boolean); 494 -- N is the node id for an identifier from a pragma Restrictions for the 495 -- No_Specification_Of_Aspect pragma. An error message will be issued if 496 -- the identifier is not a valid aspect name. Warning is set True for the 497 -- case of a Restriction_Warnings pragma specifying this restriction and 498 -- False for a Restrictions pragma specifying this restriction. 499 500 procedure Set_Restriction_No_Specification_Of_Aspect (A_Id : Aspect_Id); 501 -- Version used by Get_Target_Parameters (via Tbuild) 502 503 procedure Set_Restriction_No_Use_Of_Attribute 504 (N : Node_Id; 505 Warn : Boolean); 506 -- N is the node id for the identifier in a pragma Restrictions for 507 -- No_Use_Of_Attribute. Caller has verified that this is a valid attribute 508 -- designator. 509 510 procedure Set_Restriction_No_Use_Of_Attribute (A_Id : Attribute_Id); 511 -- Version used by Get_Target_Parameters (via Tbuild) 512 513 procedure Set_Restriction_No_Use_Of_Entity 514 (Entity : Node_Id; 515 Warn : Boolean; 516 Profile : Profile_Name := No_Profile); 517 -- Sets given No_Use_Of_Entity restriction in table if not there already. 518 -- Warn is True if from Restriction_Warnings, or for Restrictions if the 519 -- flag Treat_Restrictions_As_Warnings is set. False if from Restrictions 520 -- and this flag is not set. Profile is set to a non-default value if the 521 -- No_Dependence restriction comes from a Profile pragma. This procedure 522 -- also takes care of setting the Boolean2 flag of the simple name for 523 -- the entity (to optimize table searches). 524 525 procedure Set_Restriction_No_Use_Of_Pragma 526 (N : Node_Id; 527 Warn : Boolean); 528 -- N is the node id for the identifier in a pragma Restrictions for 529 -- No_Use_Of_Pragma. Caller has verified that this is a valid pragma id. 530 531 procedure Set_Restriction_No_Use_Of_Pragma (A_Id : Pragma_Id); 532 -- Version used in call from Get_Target_Parameters (via Tbuild). 533 534 function Tasking_Allowed return Boolean; 535 pragma Inline (Tasking_Allowed); 536 -- Tests if tasking operations are allowed by the current restrictions 537 -- settings. For tasking to be allowed Max_Tasks must be non-zero. 538 539 function Global_No_Tasking return Boolean; 540 -- Returns True if the restriction No_Tasking is set in the run-time 541 -- package System or in a configuration pragmas file. 542 543 ---------------------------------------------- 544 -- Handling of Boolean Compilation Switches -- 545 ---------------------------------------------- 546 547 -- The following declarations are used for proper saving and restoring of 548 -- restrictions for separate compilation units. There are two cases: 549 550 -- For partition-wide restrictions, we just let the restrictions pragmas 551 -- pile up, and we never reset them. We might as well detect what we can 552 -- at compile time. If e.g. a with'ed unit has a restriction for one of 553 -- the partition-wide restrictions, then the binder will enforce it on 554 -- all units in the partition, including the unit with the WITH. Although 555 -- it would not be wrong to leave this till bind time, we might as well 556 -- flag it earlier at compile time. 557 558 -- For non-partition-wide restrictions, we have quite a different state 559 -- of affairs. Here it would be quite wrong to carry a restriction from 560 -- a with'ed unit to another with'ed unit, or from a package spec to the 561 -- package body. This means that we have to reset these non-partition 562 -- wide restrictions at the start of each separate compilation unit. For 563 -- units in the extended main program, we need to reset them all to the 564 -- values set by the configuration pragma file(s). For units not in the 565 -- extended main program, e.g. with'ed units, we might as well reset all 566 -- of these restrictions to off (False). The actual initial values will 567 -- be taken from the config files active when those units are compiled 568 -- as main units. 569 570 type Save_Cunit_Boolean_Restrictions is private; 571 -- Type used for saving and restoring compilation unit restrictions. 572 573 function Cunit_Boolean_Restrictions_Save 574 return Save_Cunit_Boolean_Restrictions; 575 -- This function saves the compilation unit restriction settings, leaving 576 -- them unchanged. This is used e.g. at the start of processing a context 577 -- clause, so that the main unit restrictions can be restored after all 578 -- the with'ed units have been processed. 579 580 procedure Cunit_Boolean_Restrictions_Restore 581 (R : Save_Cunit_Boolean_Restrictions); 582 -- This is the corresponding restore procedure to restore restrictions 583 -- previously saved by Cunit_Boolean_Restrictions_Save. However it does 584 -- not reset No_Elaboration_Code, this stays set if it was set before 585 -- the call, and also if it is set before the call, then the Config 586 -- setting is also updated to include this restriction. This is what 587 -- implements the special handling of No_Elaboration_Code. 588 589 procedure Save_Config_Cunit_Boolean_Restrictions; 590 -- This saves the current compilation unit restrictions in an internal 591 -- variable, and leaves them unchanged. This is called immediately after 592 -- processing the configuration file pragmas, to record the restrictions 593 -- set by these configuration file pragmas. 594 595 procedure Restore_Config_Cunit_Boolean_Restrictions; 596 -- This restores the value saved by the previous call to save config values 597 -- saved by Save_Config_Cunit_Boolean_Restrictions. It is called at the 598 -- start of processing a new unit that is part of the main sources (e.g. 599 -- a package spec when the main unit is a package body). 600 601 procedure Reset_Cunit_Boolean_Restrictions; 602 -- Turns off all non-partition-wide boolean restrictions 603 604 procedure Add_To_Config_Boolean_Restrictions (R : Restriction_Id); 605 -- Add specified restriction to stored configuration boolean restrictions. 606 -- This is used for handling the special case of No_Elaboration_Code. 607 608private 609 type Save_Cunit_Boolean_Restrictions is 610 array (Cunit_Boolean_Restrictions) of Boolean; 611 -- Type used for saving and restoring compilation unit restrictions. 612 -- See Compilation_Unit_Restrictions_[Save|Restore] subprograms. 613 614end Restrict; 615