1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . R I D E N T --
9 -- Copyright (C) 1992-2013, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
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. --
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/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
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.
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
44 ---------------------------------------------------
45 -- Note On Compile/Run-Time Consistency Checking --
46 ---------------------------------------------------
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).
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.
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.
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.
72 pragma Compiler_Unit_Warning
;
75 package System
.Rident
is
78 -- The following enumeration type defines the set of restriction
79 -- identifiers that are implemented in GNAT.
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.
85 type Restriction_Id
is
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.
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)
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
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)
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
152 -- The following require consistency checking with special rules. See
153 -- individual routines in unit Bcheck for details of what is required.
155 No_Default_Initialization
, -- GNAT
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)
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.
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
180 -- The following cases require a parameter value
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))
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.
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))
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.
202 Max_Tasks
, -- (RM D.7(19), H.4(3))
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.
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))
212 -- The remaining entries are not checked at compile/bind time
214 Max_Storage_At_Blocking
, -- (RM D.7(17))
216 Not_A_Restriction_Id
);
218 -- Synonyms permitted for historical purposes of compatibility.
219 -- Must be coordinated with Restrict.Process_Restriction_Synonym.
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
;
228 subtype All_Restrictions
is Restriction_Id
range
229 Simple_Barriers
.. Max_Storage_At_Blocking
;
230 -- All restrictions (excluding only Not_A_Restriction_Id)
232 subtype All_Boolean_Restrictions
is Restriction_Id
range
233 Simple_Barriers
.. SPARK_05
;
234 -- All restrictions which do not take a parameter
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.
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.
250 subtype All_Parameter_Restrictions
is
252 No_Specification_Of_Aspect
.. Max_Storage_At_Blocking
;
253 -- All restrictions that take a parameter
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.
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.
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.
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.
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.
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.
296 -------------------------------------
297 -- Restriction Status Declarations --
298 -------------------------------------
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).
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;
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.
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.
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.
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.
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.
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.
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
357 ----------------------------------
358 -- Profile Definitions and Data --
359 ----------------------------------
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.
367 No_Implementation_Extensions
,
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].
374 subtype Profile_Name_Actual
is Profile_Name
375 range No_Implementation_Extensions
.. Restricted
;
376 -- Actual used profile names
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.
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.
392 Profile_Info
: constant array (Profile_Name_Actual
) of Profile_Data
:= (
394 -- No_Implementation_Extensions profile
396 No_Implementation_Extensions
=>
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,
406 -- Value settings for Restricted profile (none
411 -- Restricted Profile
415 -- Restrictions for Restricted profile
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,
436 -- Value settings for Restricted profile
439 (Max_Asynchronous_Select_Nesting
=> 0,
440 Max_Protected_Entries
=> 1,
441 Max_Select_Alternatives
=> 0,
442 Max_Task_Entries
=> 0,
447 -- Note: the table entries here only represent the
448 -- required restriction profile for Ravenscar. The
449 -- full Ravenscar profile also requires:
451 -- pragma Dispatching_Policy (FIFO_Within_Priorities);
452 -- pragma Locking_Policy (Ceiling_Locking);
453 -- pragma Detect_Blocking
457 -- Restrictions for Ravenscar = Restricted profile ..
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,
477 -- plus these additional restrictions:
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,
489 -- Value settings for Ravenscar (same as Restricted)
492 (Max_Asynchronous_Select_Nesting
=> 0,
493 Max_Protected_Entries
=> 1,
494 Max_Select_Alternatives
=> 0,
495 Max_Task_Entries
=> 0,