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) 1992-2013, 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_Point, -- (RM H.4(15)) 116 No_Floating_Point, -- (RM H.4(14)) 117 No_IO, -- (RM H.4(20)) 118 No_Implicit_Conditionals, -- GNAT 119 No_Implicit_Dynamic_Code, -- GNAT 120 No_Implicit_Heap_Allocations, -- (RM D.8(8), H.4(3)) 121 No_Implicit_Loops, -- GNAT 122 No_Initialize_Scalars, -- GNAT 123 No_Local_Allocators, -- (RM H.4(8)) 124 No_Local_Timing_Events, -- (RM D.7(10.2/2)) 125 No_Local_Protected_Objects, -- Ada 2012 (D.7(10/1.3)) 126 No_Nested_Finalization, -- (RM D.7(4)) 127 No_Protected_Type_Allocators, -- Ada 2012 (D.7 (10.3/2)) 128 No_Protected_Types, -- (RM H.4(5)) 129 No_Recursion, -- (RM H.4(22)) 130 No_Reentrancy, -- (RM H.4(23)) 131 No_Relative_Delay, -- Ada 2012 (D.7 (10.5/3)) 132 No_Requeue_Statements, -- Ada 2012 (D.7 (10.6/3)) 133 No_Secondary_Stack, -- GNAT 134 No_Select_Statements, -- Ada 2012 (D.7 (10.7/4)) 135 No_Specific_Termination_Handlers, -- (RM D.7(10.7/2)) 136 No_Standard_Allocators_After_Elaboration, -- Ada 2012 (RM D.7(19.1/2)) 137 No_Standard_Storage_Pools, -- GNAT 138 No_Stream_Optimizations, -- GNAT 139 No_Streams, -- GNAT 140 No_Task_Allocators, -- (RM D.7(7)) 141 No_Task_Attributes_Package, -- GNAT 142 No_Task_Hierarchy, -- (RM D.7(3), H.4(3)) 143 No_Task_Termination, -- GNAT (Ravenscar) 144 No_Tasking, -- GNAT 145 No_Terminate_Alternatives, -- (RM D.7(6)) 146 No_Unchecked_Access, -- (RM H.4(18)) 147 No_Unchecked_Conversion, -- (RM J.13(4/2)) 148 No_Unchecked_Deallocation, -- (RM J.13(5/2)) 149 Static_Priorities, -- GNAT 150 Static_Storage_Size, -- GNAT 151 152 -- The following require consistency checking with special rules. See 153 -- individual routines in unit Bcheck for details of what is required. 154 155 No_Default_Initialization, -- GNAT 156 157 -- The following cases do not require consistency checking and if used 158 -- as a configuration pragma within a specific unit, apply only to that 159 -- unit (e.g. if used in the package spec, do not apply to the body) 160 161 -- Note: No_Elaboration_Code is handled specially. Like the other 162 -- non-partition-wide restrictions, it can only be set in a unit that 163 -- is part of the extended main source unit (body/spec/subunits). But 164 -- it is sticky, in that if it is found anywhere within any of these 165 -- units, it applies to all units in this extended main source. 166 167 Immediate_Reclamation, -- (RM H.4(10)) 168 No_Implementation_Aspect_Specifications, -- Ada 2012 AI-241 169 No_Implementation_Attributes, -- Ada 2005 AI-257 170 No_Implementation_Identifiers, -- Ada 2012 AI-246 171 No_Implementation_Pragmas, -- Ada 2005 AI-257 172 No_Implementation_Restrictions, -- GNAT 173 No_Implementation_Units, -- Ada 2012 AI-242 174 No_Implicit_Aliasing, -- GNAT 175 No_Elaboration_Code, -- GNAT 176 No_Obsolescent_Features, -- Ada 2005 AI-368 177 No_Wide_Characters, -- GNAT 178 SPARK_05, -- GNAT 179 180 -- The following cases require a parameter value 181 182 No_Specification_Of_Aspect, -- 2012 (RM 13.12.1 (6.1/3)) 183 No_Use_Of_Attribute, -- 2012 (RM 13.12.1 (6.2/3)) 184 No_Use_Of_Pragma, -- 2012 (RM 13.12.1 (6.3/3)) 185 186 -- The following entries are fully checked at compile/bind time, which 187 -- means that the compiler can in general tell the minimum value which 188 -- could be used with a restrictions pragma. The binder can deduce the 189 -- appropriate minimum value for the partition by taking the maximum 190 -- value required by any unit. 191 192 Max_Protected_Entries, -- (RM D.7(14)) 193 Max_Select_Alternatives, -- (RM D.7(12)) 194 Max_Task_Entries, -- (RM D.7(13), H.4(3)) 195 196 -- The following entries are also fully checked at compile/bind time, 197 -- and the compiler can also at least in some cases tell the minimum 198 -- value which could be used with a restriction pragma. The difference 199 -- is that the contributions are additive, so the binder deduces this 200 -- value by adding the unit contributions. 201 202 Max_Tasks, -- (RM D.7(19), H.4(3)) 203 204 -- The following entries are checked at compile time only for zero/ 205 -- nonzero entries. This means that the compiler can tell at compile 206 -- time if a restriction value of zero is (would be) violated, but that 207 -- the compiler cannot distinguish between different non-zero values. 208 209 Max_Asynchronous_Select_Nesting, -- (RM D.7(18), H.4(3)) 210 Max_Entry_Queue_Length, -- Ada 2012 (RM D.7 (19.1/2)) 211 212 -- The remaining entries are not checked at compile/bind time 213 214 Max_Storage_At_Blocking, -- (RM D.7(17)) 215 216 Not_A_Restriction_Id); 217 218 -- Synonyms permitted for historical purposes of compatibility. 219 -- Must be coordinated with Restrict.Process_Restriction_Synonym. 220 221 Boolean_Entry_Barriers : Restriction_Id renames Simple_Barriers; 222 Max_Entry_Queue_Depth : Restriction_Id renames Max_Entry_Queue_Length; 223 No_Dynamic_Interrupts : Restriction_Id renames No_Dynamic_Attachment; 224 No_Requeue : Restriction_Id renames No_Requeue_Statements; 225 No_Task_Attributes : Restriction_Id renames No_Task_Attributes_Package; 226 SPARK : Restriction_Id renames SPARK_05; 227 228 subtype All_Restrictions is Restriction_Id range 229 Simple_Barriers .. Max_Storage_At_Blocking; 230 -- All restrictions (excluding only Not_A_Restriction_Id) 231 232 subtype All_Boolean_Restrictions is Restriction_Id range 233 Simple_Barriers .. SPARK_05; 234 -- All restrictions which do not take a parameter 235 236 subtype Partition_Boolean_Restrictions is All_Boolean_Restrictions range 237 Simple_Barriers .. Static_Storage_Size; 238 -- Boolean restrictions that are checked for partition consistency. 239 -- Note that all parameter restrictions are checked for partition 240 -- consistency by default, so this distinction is only needed in the 241 -- case of Boolean restrictions. 242 243 subtype Cunit_Boolean_Restrictions is All_Boolean_Restrictions range 244 Immediate_Reclamation .. SPARK_05; 245 -- Boolean restrictions that are not checked for partition consistency 246 -- and that thus apply only to the current unit. Note that for these 247 -- restrictions, the compiler does not apply restrictions found in 248 -- with'ed units, parent specs etc. to the main unit, and vice versa. 249 250 subtype All_Parameter_Restrictions is 251 Restriction_Id range 252 No_Specification_Of_Aspect .. Max_Storage_At_Blocking; 253 -- All restrictions that take a parameter 254 255 subtype Checked_Parameter_Restrictions is 256 All_Parameter_Restrictions range 257 Max_Protected_Entries .. Max_Entry_Queue_Length; 258 -- These are the parameter restrictions that can be at least partially 259 -- checked at compile/binder time. Minimally, the compiler can detect 260 -- violations of a restriction pragma with a value of zero reliably. 261 262 subtype Checked_Max_Parameter_Restrictions is 263 Checked_Parameter_Restrictions range 264 Max_Protected_Entries .. Max_Task_Entries; 265 -- Restrictions with parameters that can be checked in some cases by 266 -- maximizing among statically detected instances where the compiler 267 -- can determine the count. 268 269 subtype Checked_Add_Parameter_Restrictions is 270 Checked_Parameter_Restrictions range 271 Max_Tasks .. Max_Tasks; 272 -- Restrictions with parameters that can be checked in some cases by 273 -- summing the statically detected instances where the compiler can 274 -- determine the count. 275 276 subtype Checked_Val_Parameter_Restrictions is 277 Checked_Parameter_Restrictions range 278 Max_Protected_Entries .. Max_Tasks; 279 -- Restrictions with parameter where the count is known at least in some 280 -- cases by the compiler/binder. 281 282 subtype Checked_Zero_Parameter_Restrictions is 283 Checked_Parameter_Restrictions range 284 Max_Asynchronous_Select_Nesting .. Max_Entry_Queue_Length; 285 -- Restrictions with parameters where the compiler can detect the use of 286 -- the feature, and hence violations of a restriction specifying a value 287 -- of zero, but cannot detect specific values other than zero/nonzero. 288 289 subtype Unchecked_Parameter_Restrictions is 290 All_Parameter_Restrictions range 291 Max_Storage_At_Blocking .. Max_Storage_At_Blocking; 292 -- Restrictions with parameters where the compiler cannot ever detect 293 -- corresponding compile time usage, so the binder and compiler never 294 -- detect violations of any restriction. 295 296 ------------------------------------- 297 -- Restriction Status Declarations -- 298 ------------------------------------- 299 300 -- The following declarations are used to record the current status or 301 -- restrictions (for the current unit, or related units, at compile time, 302 -- and for all units in a partition at bind time or run time). 303 304 type Restriction_Flags is array (All_Restrictions) of Boolean; 305 type Restriction_Values is array (All_Parameter_Restrictions) of Natural; 306 type Parameter_Flags is array (All_Parameter_Restrictions) of Boolean; 307 308 type Restrictions_Info is record 309 Set : Restriction_Flags; 310 -- An entry is True in the Set array if a restrictions pragma has been 311 -- encountered for the given restriction. If the value is True for a 312 -- parameter restriction, then the corresponding entry in the Value 313 -- array gives the minimum value encountered for any such restriction. 314 315 Value : Restriction_Values; 316 -- If the entry for a parameter restriction in Set is True (i.e. a 317 -- restrictions pragma for the restriction has been encountered), then 318 -- the corresponding entry in the Value array is the minimum value 319 -- specified by any such restrictions pragma. Note that a restrictions 320 -- pragma specifying a value greater than Int'Last is simply ignored. 321 322 Violated : Restriction_Flags; 323 -- An entry is True in the violations array if the compiler has detected 324 -- a violation of the restriction. For a parameter restriction, the 325 -- Count and Unknown arrays have additional information. 326 327 Count : Restriction_Values; 328 -- If an entry for a parameter restriction is True in Violated, the 329 -- corresponding entry in the Count array may record additional 330 -- information. If the actual minimum count is known (by taking 331 -- maximums, or sums, depending on the restriction), it will be 332 -- recorded in this array. If not, then the value will remain zero. 333 -- The value is also zero for a non-violated restriction. 334 335 Unknown : Parameter_Flags; 336 -- If an entry for a parameter restriction is True in Violated, the 337 -- corresponding entry in the Unknown array may record additional 338 -- information. If the actual count is not known by the compiler (but 339 -- is known to be non-zero), then the entry in Unknown will be True. 340 -- This indicates that the value in Count is not known to be exact, 341 -- and the actual violation count may be higher. 342 343 -- Note: If Violated (K) is True, then either Count (K) > 0 or 344 -- Unknown (K) = True. It is possible for both these to be set. 345 -- For example, if Count (K) = 3 and Unknown (K) is True, it means 346 -- that the actual violation count is at least 3 but might be higher. 347 end record; 348 349 No_Restrictions : constant Restrictions_Info := 350 (Set => (others => False), 351 Value => (others => 0), 352 Violated => (others => False), 353 Count => (others => 0), 354 Unknown => (others => False)); 355 -- Used to initialize Restrictions_Info variables 356 357 ---------------------------------- 358 -- Profile Definitions and Data -- 359 ---------------------------------- 360 361 -- Note: to add a profile, modify the following declarations appropriately, 362 -- add Name_xxx to Snames, and add a branch to the conditions for pragmas 363 -- Profile and Profile_Warnings in the body of Sem_Prag. 364 365 type Profile_Name is 366 (No_Profile, 367 No_Implementation_Extensions, 368 Ravenscar, 369 Restricted); 370 -- Names of recognized profiles. No_Profile is used to indicate that a 371 -- restriction came from pragma Restrictions[_Warning], as opposed to 372 -- pragma Profile[_Warning]. 373 374 subtype Profile_Name_Actual is Profile_Name 375 range No_Implementation_Extensions .. Restricted; 376 -- Actual used profile names 377 378 type Profile_Data is record 379 Set : Restriction_Flags; 380 -- Set to True if given restriction must be set for the profile, and 381 -- False if it need not be set (False does not mean that it must not be 382 -- set, just that it need not be set). If the flag is True for a 383 -- parameter restriction, then the Value array gives the maximum value 384 -- permitted by the profile. 385 386 Value : Restriction_Values; 387 -- An entry in this array is meaningful only if the corresponding flag 388 -- in Set is True. In that case, the value in this array is the maximum 389 -- value of the parameter permitted by the profile. 390 end record; 391 392 Profile_Info : constant array (Profile_Name_Actual) of Profile_Data := ( 393 394 -- No_Implementation_Extensions profile 395 396 No_Implementation_Extensions => 397 398 (Set => 399 (No_Implementation_Aspect_Specifications => True, 400 No_Implementation_Attributes => True, 401 No_Implementation_Identifiers => True, 402 No_Implementation_Pragmas => True, 403 No_Implementation_Units => True, 404 others => False), 405 406 -- Value settings for Restricted profile (none 407 408 Value => 409 (others => 0)), 410 411 -- Restricted Profile 412 413 Restricted => 414 415 -- Restrictions for Restricted profile 416 417 (Set => 418 (No_Abort_Statements => True, 419 No_Asynchronous_Control => True, 420 No_Dynamic_Attachment => True, 421 No_Dynamic_Priorities => True, 422 No_Entry_Queue => True, 423 No_Local_Protected_Objects => True, 424 No_Protected_Type_Allocators => True, 425 No_Requeue_Statements => True, 426 No_Task_Allocators => True, 427 No_Task_Attributes_Package => True, 428 No_Task_Hierarchy => True, 429 No_Terminate_Alternatives => True, 430 Max_Asynchronous_Select_Nesting => True, 431 Max_Protected_Entries => True, 432 Max_Select_Alternatives => True, 433 Max_Task_Entries => True, 434 others => False), 435 436 -- Value settings for Restricted profile 437 438 Value => 439 (Max_Asynchronous_Select_Nesting => 0, 440 Max_Protected_Entries => 1, 441 Max_Select_Alternatives => 0, 442 Max_Task_Entries => 0, 443 others => 0)), 444 445 -- Ravenscar Profile 446 447 -- Note: the table entries here only represent the 448 -- required restriction profile for Ravenscar. The 449 -- full Ravenscar profile also requires: 450 451 -- pragma Dispatching_Policy (FIFO_Within_Priorities); 452 -- pragma Locking_Policy (Ceiling_Locking); 453 -- pragma Detect_Blocking 454 455 Ravenscar => 456 457 -- Restrictions for Ravenscar = Restricted profile .. 458 459 (Set => 460 (No_Abort_Statements => True, 461 No_Asynchronous_Control => True, 462 No_Dynamic_Attachment => True, 463 No_Dynamic_Priorities => True, 464 No_Entry_Queue => True, 465 No_Local_Protected_Objects => True, 466 No_Protected_Type_Allocators => True, 467 No_Requeue_Statements => True, 468 No_Task_Allocators => True, 469 No_Task_Attributes_Package => True, 470 No_Task_Hierarchy => True, 471 No_Terminate_Alternatives => True, 472 Max_Asynchronous_Select_Nesting => True, 473 Max_Protected_Entries => True, 474 Max_Select_Alternatives => True, 475 Max_Task_Entries => True, 476 477 -- plus these additional restrictions: 478 479 No_Calendar => True, 480 No_Implicit_Heap_Allocations => True, 481 No_Local_Timing_Events => True, 482 No_Relative_Delay => True, 483 No_Select_Statements => True, 484 No_Specific_Termination_Handlers => True, 485 No_Task_Termination => True, 486 Simple_Barriers => True, 487 others => False), 488 489 -- Value settings for Ravenscar (same as Restricted) 490 491 Value => 492 (Max_Asynchronous_Select_Nesting => 0, 493 Max_Protected_Entries => 1, 494 Max_Select_Alternatives => 0, 495 Max_Task_Entries => 0, 496 others => 0))); 497 498end System.Rident; 499