1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S Y S T E M . R I D E N T -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2015, 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 defines the set of restriction identifiers. It is a generic 33-- package that is instantiated by the compiler/binder in package Rident, and 34-- is instantiated in package System.Restrictions for use at run-time. 35 36-- The reason that we make this a generic package is so that in the case of 37-- the instantiation in Rident for use at compile time and bind time, we can 38-- generate normal image tables for the enumeration types, which are needed 39-- for diagnostic and informational messages. At run-time we really do not 40-- want to waste the space for these image tables, and they are not needed, 41-- so we can do the instantiation under control of Discard_Names to remove 42-- the tables. 43 44--------------------------------------------------- 45-- Note On Compile/Run-Time Consistency Checking -- 46--------------------------------------------------- 47 48-- This unit is with'ed by the run-time (to make System.Restrictions which is 49-- used for run-time access to restriction information), by the compiler (to 50-- determine what restrictions are implemented and what their category is) and 51-- by the binder (in processing ali files, and generating the information used 52-- at run-time to access restriction information). 53 54-- Normally the version of System.Rident referenced in all three contexts 55-- should be the same. However, problems could arise in certain inconsistent 56-- builds that used inconsistent versions of the compiler and run-time. This 57-- sort of thing is not strictly correct, but it does arise when short-cuts 58-- are taken in build procedures. 59 60-- Previously, this kind of inconsistency could cause a significant problem. 61-- If versions of System.Rident accessed by the compiler and binder differed, 62-- then the binder could fail to recognize the R (restrictions line) in the 63-- ali file, leading to bind errors when restrictions were added or removed. 64 65-- The latest implementation avoids both this problem by using a named 66-- scheme for recording restrictions, rather than a positional scheme which 67-- fails completely if restrictions are added or subtracted. Now the worst 68-- that happens at bind time in inconsistent builds is that unrecognized 69-- restrictions are ignored, and the consistency checking for restrictions 70-- might be incomplete, which is no big deal. 71 72pragma Compiler_Unit_Warning; 73 74generic 75package System.Rident is 76 pragma Preelaborate; 77 78 -- The following enumeration type defines the set of restriction 79 -- identifiers that are implemented in GNAT. 80 81 -- To add a new restriction identifier, add an entry with the name to be 82 -- used in the pragma, and add calls to the Restrict.Check_Restriction 83 -- routine as appropriate. 84 85 type Restriction_Id is 86 87 -- The following cases are checked for consistency in the binder. The 88 -- binder will check that every unit either has the restriction set, or 89 -- does not violate the restriction. 90 91 (Simple_Barriers, -- Ada 2012 (D.7 (10.9/3)) 92 No_Abort_Statements, -- (RM D.7(5), H.4(3)) 93 No_Access_Parameter_Allocators, -- Ada 2012 (RM H.4 (8.3/3)) 94 No_Access_Subprograms, -- (RM H.4(17)) 95 No_Allocators, -- (RM H.4(7)) 96 No_Anonymous_Allocators, -- Ada 2012 (RM H.4(8/1)) 97 No_Asynchronous_Control, -- (RM J.13(3/2) 98 No_Calendar, -- GNAT 99 No_Coextensions, -- Ada 2012 (RM H.4(8.2/3)) 100 No_Default_Stream_Attributes, -- Ada 2012 (RM 13.12.1(4/2)) 101 No_Delay, -- (RM H.4(21)) 102 No_Direct_Boolean_Operators, -- GNAT 103 No_Dispatch, -- (RM H.4(19)) 104 No_Dispatching_Calls, -- GNAT 105 No_Dynamic_Attachment, -- Ada 2012 (RM E.7(10/3)) 106 No_Dynamic_Priorities, -- (RM D.9(9)) 107 No_Enumeration_Maps, -- GNAT 108 No_Entry_Calls_In_Elaboration_Code, -- GNAT 109 No_Entry_Queue, -- GNAT (Ravenscar) 110 No_Exception_Handlers, -- GNAT 111 No_Exception_Propagation, -- GNAT 112 No_Exception_Registration, -- GNAT 113 No_Exceptions, -- (RM H.4(12)) 114 No_Finalization, -- GNAT 115 No_Fixed_IO, -- GNAT 116 No_Fixed_Point, -- (RM H.4(15)) 117 No_Floating_Point, -- (RM H.4(14)) 118 No_IO, -- (RM H.4(20)) 119 No_Implicit_Conditionals, -- GNAT 120 No_Implicit_Dynamic_Code, -- GNAT 121 No_Implicit_Heap_Allocations, -- (RM D.8(8), H.4(3)) 122 No_Implicit_Task_Allocations, -- GNAT 123 No_Implicit_Protected_Object_Allocations, -- GNAT 124 No_Implicit_Loops, -- GNAT 125 No_Initialize_Scalars, -- GNAT 126 No_Local_Allocators, -- (RM H.4(8)) 127 No_Local_Timing_Events, -- (RM D.7(10.2/2)) 128 No_Local_Protected_Objects, -- Ada 2012 (D.7(10/1.3)) 129 No_Long_Long_Integers, -- GNAT 130 No_Multiple_Elaboration, -- GNAT 131 No_Nested_Finalization, -- (RM D.7(4)) 132 No_Protected_Type_Allocators, -- Ada 2012 (D.7 (10.3/2)) 133 No_Protected_Types, -- (RM H.4(5)) 134 No_Recursion, -- (RM H.4(22)) 135 No_Reentrancy, -- (RM H.4(23)) 136 No_Relative_Delay, -- Ada 2012 (D.7 (10.5/3)) 137 No_Requeue_Statements, -- Ada 2012 (D.7 (10.6/3)) 138 No_Secondary_Stack, -- GNAT 139 No_Select_Statements, -- Ada 2012 (D.7 (10.7/4)) 140 No_Specific_Termination_Handlers, -- (RM D.7(10.7/2)) 141 No_Standard_Allocators_After_Elaboration, -- Ada 2012 (RM D.7(19.1/2)) 142 No_Standard_Storage_Pools, -- GNAT 143 No_Stream_Optimizations, -- GNAT 144 No_Streams, -- GNAT 145 No_Task_Allocators, -- (RM D.7(7)) 146 No_Task_Attributes_Package, -- GNAT 147 No_Task_At_Interrupt_Priority, -- GNAT 148 No_Task_Hierarchy, -- (RM D.7(3), H.4(3)) 149 No_Task_Termination, -- GNAT (Ravenscar) 150 No_Tasking, -- GNAT 151 No_Terminate_Alternatives, -- (RM D.7(6)) 152 No_Unchecked_Access, -- (RM H.4(18)) 153 No_Unchecked_Conversion, -- (RM J.13(4/2)) 154 No_Unchecked_Deallocation, -- (RM J.13(5/2)) 155 Static_Priorities, -- GNAT 156 Static_Storage_Size, -- GNAT 157 158 -- The following require consistency checking with special rules. See 159 -- individual routines in unit Bcheck for details of what is required. 160 161 No_Default_Initialization, -- GNAT 162 163 -- The following cases do not require consistency checking and if used 164 -- as a configuration pragma within a specific unit, apply only to that 165 -- unit (e.g. if used in the package spec, do not apply to the body) 166 167 -- Note: No_Elaboration_Code is handled specially. Like the other 168 -- non-partition-wide restrictions, it can only be set in a unit that 169 -- is part of the extended main source unit (body/spec/subunits). But 170 -- it is sticky, in that if it is found anywhere within any of these 171 -- units, it applies to all units in this extended main source. 172 173 Immediate_Reclamation, -- (RM H.4(10)) 174 No_Dynamic_Sized_Objects, -- GNAT 175 No_Implementation_Aspect_Specifications, -- Ada 2012 AI-241 176 No_Implementation_Attributes, -- Ada 2005 AI-257 177 No_Implementation_Identifiers, -- Ada 2012 AI-246 178 No_Implementation_Pragmas, -- Ada 2005 AI-257 179 No_Implementation_Restrictions, -- GNAT 180 No_Implementation_Units, -- Ada 2012 AI-242 181 No_Implicit_Aliasing, -- GNAT 182 No_Elaboration_Code, -- GNAT 183 No_Obsolescent_Features, -- Ada 2005 AI-368 184 No_Wide_Characters, -- GNAT 185 Pure_Barriers, -- GNAT 186 SPARK_05, -- GNAT 187 188 -- The following cases require a parameter value 189 190 No_Specification_Of_Aspect, -- 2012 (RM 13.12.1 (6.1/3)) 191 No_Use_Of_Attribute, -- 2012 (RM 13.12.1 (6.2/3)) 192 No_Use_Of_Pragma, -- 2012 (RM 13.12.1 (6.3/3)) 193 194 -- The following entries are fully checked at compile/bind time, which 195 -- means that the compiler can in general tell the minimum value which 196 -- could be used with a restrictions pragma. The binder can deduce the 197 -- appropriate minimum value for the partition by taking the maximum 198 -- value required by any unit. 199 200 Max_Protected_Entries, -- (RM D.7(14)) 201 Max_Select_Alternatives, -- (RM D.7(12)) 202 Max_Task_Entries, -- (RM D.7(13), H.4(3)) 203 204 -- The following entries are also fully checked at compile/bind time, 205 -- and the compiler can also at least in some cases tell the minimum 206 -- value which could be used with a restriction pragma. The difference 207 -- is that the contributions are additive, so the binder deduces this 208 -- value by adding the unit contributions. 209 210 Max_Tasks, -- (RM D.7(19), H.4(3)) 211 212 -- The following entries are checked at compile time only for zero/ 213 -- nonzero entries. This means that the compiler can tell at compile 214 -- time if a restriction value of zero is (would be) violated, but that 215 -- the compiler cannot distinguish between different non-zero values. 216 217 Max_Asynchronous_Select_Nesting, -- (RM D.7(18), H.4(3)) 218 Max_Entry_Queue_Length, -- Ada 2012 (RM D.7 (19.1/2)) 219 220 -- The remaining entries are not checked at compile/bind time 221 222 Max_Storage_At_Blocking, -- (RM D.7(17)) 223 224 Not_A_Restriction_Id); 225 226 -- Synonyms permitted for historical purposes of compatibility. 227 -- Must be coordinated with Restrict.Process_Restriction_Synonym. 228 229 Boolean_Entry_Barriers : Restriction_Id renames Simple_Barriers; 230 Max_Entry_Queue_Depth : Restriction_Id renames Max_Entry_Queue_Length; 231 No_Dynamic_Interrupts : Restriction_Id renames No_Dynamic_Attachment; 232 No_Requeue : Restriction_Id renames No_Requeue_Statements; 233 No_Task_Attributes : Restriction_Id renames No_Task_Attributes_Package; 234 SPARK : Restriction_Id renames SPARK_05; 235 236 subtype All_Restrictions is Restriction_Id range 237 Simple_Barriers .. Max_Storage_At_Blocking; 238 -- All restrictions (excluding only Not_A_Restriction_Id) 239 240 subtype All_Boolean_Restrictions is Restriction_Id range 241 Simple_Barriers .. SPARK_05; 242 -- All restrictions which do not take a parameter 243 244 subtype Partition_Boolean_Restrictions is All_Boolean_Restrictions range 245 Simple_Barriers .. Static_Storage_Size; 246 -- Boolean restrictions that are checked for partition consistency. 247 -- Note that all parameter restrictions are checked for partition 248 -- consistency by default, so this distinction is only needed in the 249 -- case of Boolean restrictions. 250 251 subtype Cunit_Boolean_Restrictions is All_Boolean_Restrictions range 252 Immediate_Reclamation .. SPARK_05; 253 -- Boolean restrictions that are not checked for partition consistency 254 -- and that thus apply only to the current unit. Note that for these 255 -- restrictions, the compiler does not apply restrictions found in 256 -- with'ed units, parent specs etc. to the main unit, and vice versa. 257 258 subtype All_Parameter_Restrictions is 259 Restriction_Id range 260 No_Specification_Of_Aspect .. Max_Storage_At_Blocking; 261 -- All restrictions that take a parameter 262 263 subtype Integer_Parameter_Restrictions is 264 Restriction_Id range 265 Max_Protected_Entries .. Max_Storage_At_Blocking; 266 -- All restrictions taking an integer parameter 267 268 subtype Checked_Parameter_Restrictions is 269 All_Parameter_Restrictions range 270 Max_Protected_Entries .. Max_Entry_Queue_Length; 271 -- These are the parameter restrictions that can be at least partially 272 -- checked at compile/binder time. Minimally, the compiler can detect 273 -- violations of a restriction pragma with a value of zero reliably. 274 275 subtype Checked_Max_Parameter_Restrictions is 276 Checked_Parameter_Restrictions range 277 Max_Protected_Entries .. Max_Task_Entries; 278 -- Restrictions with parameters that can be checked in some cases by 279 -- maximizing among statically detected instances where the compiler 280 -- can determine the count. 281 282 subtype Checked_Add_Parameter_Restrictions is 283 Checked_Parameter_Restrictions range 284 Max_Tasks .. Max_Tasks; 285 -- Restrictions with parameters that can be checked in some cases by 286 -- summing the statically detected instances where the compiler can 287 -- determine the count. 288 289 subtype Checked_Val_Parameter_Restrictions is 290 Checked_Parameter_Restrictions range 291 Max_Protected_Entries .. Max_Tasks; 292 -- Restrictions with parameter where the count is known at least in some 293 -- cases by the compiler/binder. 294 295 subtype Checked_Zero_Parameter_Restrictions is 296 Checked_Parameter_Restrictions range 297 Max_Asynchronous_Select_Nesting .. Max_Entry_Queue_Length; 298 -- Restrictions with parameters where the compiler can detect the use of 299 -- the feature, and hence violations of a restriction specifying a value 300 -- of zero, but cannot detect specific values other than zero/nonzero. 301 302 subtype Unchecked_Parameter_Restrictions is 303 All_Parameter_Restrictions range 304 Max_Storage_At_Blocking .. Max_Storage_At_Blocking; 305 -- Restrictions with parameters where the compiler cannot ever detect 306 -- corresponding compile time usage, so the binder and compiler never 307 -- detect violations of any restriction. 308 309 ------------------------------------- 310 -- Restriction Status Declarations -- 311 ------------------------------------- 312 313 -- The following declarations are used to record the current status or 314 -- restrictions (for the current unit, or related units, at compile time, 315 -- and for all units in a partition at bind time or run time). 316 317 type Restriction_Flags is array (All_Restrictions) of Boolean; 318 type Restriction_Values is array (All_Parameter_Restrictions) of Natural; 319 type Parameter_Flags is array (All_Parameter_Restrictions) of Boolean; 320 321 type Restrictions_Info is record 322 Set : Restriction_Flags; 323 -- An entry is True in the Set array if a restrictions pragma has been 324 -- encountered for the given restriction. If the value is True for a 325 -- parameter restriction, then the corresponding entry in the Value 326 -- array gives the minimum value encountered for any such restriction. 327 328 Value : Restriction_Values; 329 -- If the entry for a parameter restriction in Set is True (i.e. a 330 -- restrictions pragma for the restriction has been encountered), then 331 -- the corresponding entry in the Value array is the minimum value 332 -- specified by any such restrictions pragma. Note that a restrictions 333 -- pragma specifying a value greater than Int'Last is simply ignored. 334 335 Violated : Restriction_Flags; 336 -- An entry is True in the violations array if the compiler has detected 337 -- a violation of the restriction. For a parameter restriction, the 338 -- Count and Unknown arrays have additional information. 339 340 Count : Restriction_Values; 341 -- If an entry for a parameter restriction is True in Violated, the 342 -- corresponding entry in the Count array may record additional 343 -- information. If the actual minimum count is known (by taking 344 -- maximums, or sums, depending on the restriction), it will be 345 -- recorded in this array. If not, then the value will remain zero. 346 -- The value is also zero for a non-violated restriction. 347 348 Unknown : Parameter_Flags; 349 -- If an entry for a parameter restriction is True in Violated, the 350 -- corresponding entry in the Unknown array may record additional 351 -- information. If the actual count is not known by the compiler (but 352 -- is known to be non-zero), then the entry in Unknown will be True. 353 -- This indicates that the value in Count is not known to be exact, 354 -- and the actual violation count may be higher. 355 356 -- Note: If Violated (K) is True, then either Count (K) > 0 or 357 -- Unknown (K) = True. It is possible for both these to be set. 358 -- For example, if Count (K) = 3 and Unknown (K) is True, it means 359 -- that the actual violation count is at least 3 but might be higher. 360 end record; 361 362 No_Restrictions : constant Restrictions_Info := 363 (Set => (others => False), 364 Value => (others => 0), 365 Violated => (others => False), 366 Count => (others => 0), 367 Unknown => (others => False)); 368 -- Used to initialize Restrictions_Info variables 369 370 ---------------------------------- 371 -- Profile Definitions and Data -- 372 ---------------------------------- 373 374 -- Note: to add a profile, modify the following declarations appropriately, 375 -- add Name_xxx to Snames, and add a branch to the conditions for pragmas 376 -- Profile and Profile_Warnings in the body of Sem_Prag. 377 378 type Profile_Name is 379 (No_Profile, 380 No_Implementation_Extensions, 381 Ravenscar, 382 GNAT_Extended_Ravenscar, 383 Restricted); 384 -- Names of recognized profiles. No_Profile is used to indicate that a 385 -- restriction came from pragma Restrictions[_Warning], as opposed to 386 -- pragma Profile[_Warning]. 387 388 subtype Profile_Name_Actual is Profile_Name 389 range No_Implementation_Extensions .. Restricted; 390 -- Actual used profile names 391 392 type Profile_Data is record 393 Set : Restriction_Flags; 394 -- Set to True if given restriction must be set for the profile, and 395 -- False if it need not be set (False does not mean that it must not be 396 -- set, just that it need not be set). If the flag is True for a 397 -- parameter restriction, then the Value array gives the maximum value 398 -- permitted by the profile. 399 400 Value : Restriction_Values; 401 -- An entry in this array is meaningful only if the corresponding flag 402 -- in Set is True. In that case, the value in this array is the maximum 403 -- value of the parameter permitted by the profile. 404 end record; 405 406 Profile_Info : constant array (Profile_Name_Actual) of Profile_Data := ( 407 408 -- No_Implementation_Extensions profile 409 410 No_Implementation_Extensions => 411 412 (Set => 413 (No_Implementation_Aspect_Specifications => True, 414 No_Implementation_Attributes => True, 415 No_Implementation_Identifiers => True, 416 No_Implementation_Pragmas => True, 417 No_Implementation_Units => True, 418 others => False), 419 420 -- Value settings for Restricted profile (none 421 422 Value => 423 (others => 0)), 424 425 -- Restricted Profile 426 427 Restricted => 428 429 -- Restrictions for Restricted profile 430 431 (Set => 432 (No_Abort_Statements => True, 433 No_Asynchronous_Control => True, 434 No_Dynamic_Attachment => True, 435 No_Dynamic_Priorities => True, 436 No_Entry_Queue => True, 437 No_Local_Protected_Objects => True, 438 No_Protected_Type_Allocators => True, 439 No_Requeue_Statements => True, 440 No_Task_Allocators => True, 441 No_Task_Attributes_Package => True, 442 No_Task_Hierarchy => True, 443 No_Terminate_Alternatives => True, 444 Max_Asynchronous_Select_Nesting => True, 445 Max_Protected_Entries => True, 446 Max_Select_Alternatives => True, 447 Max_Task_Entries => True, 448 others => False), 449 450 -- Value settings for Restricted profile 451 452 Value => 453 (Max_Asynchronous_Select_Nesting => 0, 454 Max_Protected_Entries => 1, 455 Max_Select_Alternatives => 0, 456 Max_Task_Entries => 0, 457 others => 0)), 458 459 -- Ravenscar Profile 460 461 -- Note: the table entries here only represent the 462 -- required restriction profile for Ravenscar. The 463 -- full Ravenscar profile also requires: 464 465 -- pragma Dispatching_Policy (FIFO_Within_Priorities); 466 -- pragma Locking_Policy (Ceiling_Locking); 467 -- pragma Detect_Blocking; 468 469 Ravenscar => 470 471 -- Restrictions for Ravenscar = Restricted profile .. 472 473 (Set => 474 (No_Abort_Statements => True, 475 No_Asynchronous_Control => True, 476 No_Dynamic_Attachment => True, 477 No_Dynamic_Priorities => True, 478 No_Entry_Queue => True, 479 No_Local_Protected_Objects => True, 480 No_Protected_Type_Allocators => True, 481 No_Requeue_Statements => True, 482 No_Task_Allocators => True, 483 No_Task_Attributes_Package => True, 484 No_Task_Hierarchy => True, 485 No_Terminate_Alternatives => True, 486 Max_Asynchronous_Select_Nesting => True, 487 Max_Protected_Entries => True, 488 Max_Select_Alternatives => True, 489 Max_Task_Entries => True, 490 491 -- plus these additional restrictions: 492 493 No_Calendar => True, 494 No_Implicit_Heap_Allocations => True, 495 No_Local_Timing_Events => True, 496 No_Relative_Delay => True, 497 No_Select_Statements => True, 498 No_Specific_Termination_Handlers => True, 499 No_Task_Termination => True, 500 Simple_Barriers => True, 501 others => False), 502 503 -- Value settings for Ravenscar (same as Restricted) 504 505 Value => 506 (Max_Asynchronous_Select_Nesting => 0, 507 Max_Protected_Entries => 1, 508 Max_Select_Alternatives => 0, 509 Max_Task_Entries => 0, 510 others => 0)), 511 512 GNAT_Extended_Ravenscar => 513 514 -- Restrictions for GNAT_Extended_Ravenscar = 515 -- Restricted profile .. 516 517 (Set => 518 (No_Abort_Statements => True, 519 No_Asynchronous_Control => True, 520 No_Dynamic_Attachment => True, 521 No_Dynamic_Priorities => True, 522 No_Entry_Queue => True, 523 No_Local_Protected_Objects => True, 524 No_Protected_Type_Allocators => True, 525 No_Requeue_Statements => True, 526 No_Task_Allocators => True, 527 No_Task_Attributes_Package => True, 528 No_Task_Hierarchy => True, 529 No_Terminate_Alternatives => True, 530 Max_Asynchronous_Select_Nesting => True, 531 Max_Protected_Entries => True, 532 Max_Select_Alternatives => True, 533 Max_Task_Entries => True, 534 535 -- plus these additional restrictions: 536 537 No_Calendar => True, 538 No_Implicit_Task_Allocations => True, 539 No_Implicit_Protected_Object_Allocations 540 => True, 541 No_Local_Timing_Events => True, 542 No_Relative_Delay => True, 543 No_Select_Statements => True, 544 No_Specific_Termination_Handlers => True, 545 No_Task_Termination => True, 546 Pure_Barriers => True, 547 others => False), 548 549 -- Value settings for Ravenscar (same as Restricted) 550 551 Value => 552 (Max_Asynchronous_Select_Nesting => 0, 553 Max_Protected_Entries => 1, 554 Max_Select_Alternatives => 0, 555 Max_Task_Entries => 0, 556 others => 0))); 557 558end System.Rident; 559