1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . R I D E N T --
9 -- Copyright (C) 1992-2004 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 -- This package defines the set of restriction identifiers. It is a generic
35 -- package that is instantiated by the compiler/binder in package Rident, and
36 -- is instantiated in package System.Restrictions for use at run-time.
38 -- The reason that we make this a generic package is so that in the case of
39 -- the instantiation in Rident for use at compile time and bind time, we can
40 -- generate normal image tables for the enumeration types, which are needed
41 -- for diagnostic and informational messages. At run-time we really do not
42 -- want to waste the space for these image tables, and they are not needed,
43 -- so we can do the instantiation under control of Discard_Names to remove
47 package System.Rident is
49 -- The following enumeration type defines the set of restriction
50 -- identifiers that are implemented in GNAT.
52 -- To add a new restriction identifier, add an entry with the name
53 -- to be used in the pragma, and add appropriate calls to the
54 -- Restrict.Check_Restriction routine.
56 type Restriction_Id is
58 -- The following cases are checked for consistency in the binder
60 (Simple_Barriers, -- GNAT (Ravenscar)
61 No_Abort_Statements, -- (RM D.7(5), H.4(3))
62 No_Access_Subprograms, -- (RM H.4(17))
63 No_Allocators, -- (RM H.4(7))
64 No_Asynchronous_Control, -- (RM D.7(10))
66 No_Delay, -- (RM H.4(21))
67 No_Direct_Boolean_Operators, -- GNAT
68 No_Dispatch, -- (RM H.4(19))
69 No_Dynamic_Attachment, -- GNAT
70 No_Dynamic_Priorities, -- (RM D.9(9))
71 No_Enumeration_Maps, -- GNAT
72 No_Entry_Calls_In_Elaboration_Code, -- GNAT
73 No_Entry_Queue, -- GNAT (Ravenscar)
74 No_Exception_Handlers, -- GNAT
75 No_Exception_Registration, -- GNAT
76 No_Exceptions, -- (RM H.4(12))
77 No_Finalization, -- GNAT
78 No_Fixed_Point, -- (RM H.4(15))
79 No_Floating_Point, -- (RM H.4(14))
80 No_IO, -- (RM H.4(20))
81 No_Implicit_Conditionals, -- GNAT
82 No_Implicit_Dynamic_Code, -- GNAT
83 No_Implicit_Heap_Allocations, -- (RM D.8(8), H.4(3))
84 No_Implicit_Loops, -- GNAT
85 No_Initialize_Scalars, -- GNAT
86 No_Local_Allocators, -- (RM H.4(8))
87 No_Local_Protected_Objects, -- GNAT
88 No_Nested_Finalization, -- (RM D.7(4))
89 No_Protected_Type_Allocators, -- GNAT
90 No_Protected_Types, -- (RM H.4(5))
91 No_Recursion, -- (RM H.4(22))
92 No_Reentrancy, -- (RM H.4(23))
93 No_Relative_Delay, -- GNAT (Ravenscar)
94 No_Requeue_Statements, -- GNAT
95 No_Secondary_Stack, -- GNAT
96 No_Select_Statements, -- GNAT (Ravenscar)
97 No_Standard_Storage_Pools, -- GNAT
99 No_Task_Allocators, -- (RM D.7(7))
100 No_Task_Attributes_Package, -- GNAT
101 No_Task_Hierarchy, -- (RM D.7(3), H.4(3))
102 No_Task_Termination, -- GNAT (Ravenscar)
104 No_Terminate_Alternatives, -- (RM D.7(6))
105 No_Unchecked_Access, -- (RM H.4(18))
106 No_Unchecked_Conversion, -- (RM H.4(16))
107 No_Unchecked_Deallocation, -- (RM H.4(9))
108 No_Wide_Characters, -- GNAT
109 Static_Priorities, -- GNAT
110 Static_Storage_Size, -- GNAT
112 -- The following cases do not require partition-wide checks
114 Immediate_Reclamation, -- (RM H.4(10))
115 No_Implementation_Attributes, -- GNAT
116 No_Implementation_Pragmas, -- GNAT
117 No_Implementation_Restrictions, -- GNAT
118 No_Elaboration_Code, -- GNAT
120 -- The following cases require a parameter value
122 -- The following entries are fully checked at compile/bind time,
123 -- which means that the compiler can in general tell the minimum
124 -- value which could be used with a restrictions pragma. The binder
125 -- can deduce the appropriate minimum value for the partition by
126 -- taking the maximum value required by any unit.
128 Max_Protected_Entries, -- (RM D.7(14))
129 Max_Select_Alternatives, -- (RM D.7(12))
130 Max_Task_Entries, -- (RM D.7(13), H.4(3))
132 -- The following entries are also fully checked at compile/bind
133 -- time, and the compiler can also at least in some cases tell
134 -- the minimum value which could be used with a restriction pragma.
135 -- The difference is that the contributions are additive, so the
136 -- binder deduces this value by adding the unit contributions.
138 Max_Tasks, -- (RM D.7(19), H.4(3))
140 -- The following entries are checked at compile time only for
141 -- zero/nonzero entries. This means that the compiler can tell
142 -- at compile time if a restriction value of zero is (would be)
143 -- violated, but that is all. The compiler cannot distinguish
144 -- between different non-zero values.
146 Max_Asynchronous_Select_Nesting, -- (RM D.7(18), H.4(3))
147 Max_Entry_Queue_Length, -- GNAT
149 -- The remaining entries are not checked at compile/bind time
151 Max_Storage_At_Blocking, -- (RM D.7(17))
153 Not_A_Restriction_Id);
155 -- Synonyms permitted for historical purposes of compatibility.
156 -- Must be coordinated with Restrict.Process_Restriction_Synonym.
158 Boolean_Entry_Barriers : Restriction_Id renames Simple_Barriers;
159 Max_Entry_Queue_Depth : Restriction_Id renames Max_Entry_Queue_Length;
160 No_Dynamic_Interrupts : Restriction_Id renames No_Dynamic_Attachment;
161 No_Requeue : Restriction_Id renames No_Requeue_Statements;
162 No_Task_Attributes : Restriction_Id renames No_Task_Attributes_Package;
164 subtype All_Restrictions is Restriction_Id range
165 Simple_Barriers .. Max_Storage_At_Blocking;
166 -- All restrictions (excluding only Not_A_Restriction_Id)
168 subtype All_Boolean_Restrictions is Restriction_Id range
169 Simple_Barriers .. No_Elaboration_Code;
170 -- All restrictions which do not take a parameter
172 subtype Partition_Boolean_Restrictions is All_Boolean_Restrictions range
173 Simple_Barriers .. Static_Storage_Size;
174 -- Boolean restrictions that are checked for partition consistency.
175 -- Note that all parameter restrictions are checked for partition
176 -- consistency by default, so this distinction is only needed in the
177 -- case of Boolean restrictions.
179 subtype Cunit_Boolean_Restrictions is All_Boolean_Restrictions range
180 Immediate_Reclamation .. No_Elaboration_Code;
181 -- Boolean restrictions that are not checked for partition consistency
182 -- and that thus apply only to the current unit. Note that for these
183 -- restrictions, the compiler does not apply restrictions found in
184 -- with'ed units, parent specs etc to the main unit.
186 subtype All_Parameter_Restrictions is
188 Max_Protected_Entries .. Max_Storage_At_Blocking;
189 -- All restrictions that are take a parameter
191 subtype Checked_Parameter_Restrictions is
192 All_Parameter_Restrictions range
193 Max_Protected_Entries .. Max_Entry_Queue_Length;
194 -- These are the parameter restrictions that can be at least partially
195 -- checked at compile/binder time. Minimally, the compiler can detect
196 -- violations of a restriction pragma with a value of zero reliably.
198 subtype Checked_Max_Parameter_Restrictions is
199 Checked_Parameter_Restrictions range
200 Max_Protected_Entries .. Max_Task_Entries;
201 -- Restrictions with parameters that can be checked in some cases by
202 -- maximizing among statically detected instances where the compiler
203 -- can determine the count.
205 subtype Checked_Add_Parameter_Restrictions is
206 Checked_Parameter_Restrictions range
207 Max_Tasks .. Max_Tasks;
208 -- Restrictions with parameters that can be checked in some cases by
209 -- summing the statically detected instances where the compiler can
210 -- determine the count.
212 subtype Checked_Val_Parameter_Restrictions is
213 Checked_Parameter_Restrictions range
214 Max_Protected_Entries .. Max_Tasks;
215 -- Restrictions with parameter where the count is known at least in
216 -- some cases by the compiler/binder.
218 subtype Checked_Zero_Parameter_Restrictions is
219 Checked_Parameter_Restrictions range
220 Max_Asynchronous_Select_Nesting .. Max_Entry_Queue_Length;
221 -- Restrictions with parameters where the compiler can detect the use of
222 -- the feature, and hence violations of a restriction specifying a value
223 -- of zero, but cannot detect specific values other than zero/nonzero.
225 subtype Unchecked_Parameter_Restrictions is
226 All_Parameter_Restrictions range
227 Max_Storage_At_Blocking .. Max_Storage_At_Blocking;
228 -- Restrictions with parameters where the compiler cannot ever detect
229 -- corresponding compile time usage, so the binder and compiler never
230 -- detect violations of any restriction.
232 -------------------------------------
233 -- Restriction Status Declarations --
234 -------------------------------------
236 -- The following declarations are used to record the current status
237 -- or restrictions (for the current unit, or related units, at compile
238 -- time, and for all units in a partition at bind time or run time).
240 type Restriction_Flags is array (All_Restrictions) of Boolean;
241 type Restriction_Values is array (All_Parameter_Restrictions) of Natural;
242 type Parameter_Flags is array (All_Parameter_Restrictions) of Boolean;
244 type Restrictions_Info is record
245 Set : Restriction_Flags := (others => False);
246 -- An entry is True in the Set array if a restrictions pragma has
247 -- been encountered for the given restriction. If the value is
248 -- True for a parameter restriction, then the corresponding entry
249 -- in the Value array gives the minimum value encountered for any
252 Value : Restriction_Values;
253 -- If the entry for a parameter restriction in Set is True (i.e. a
254 -- restrictions pragma for the restriction has been encountered), then
255 -- the corresponding entry in the Value array is the minimum value
256 -- specified by any such restrictions pragma. Note that a restrictions
257 -- pragma specifying a value greater than Int'Last is simply ignored.
259 Violated : Restriction_Flags := (others => False);
260 -- An entry is True in the violations array if the compiler has
261 -- detected a violation of the restriction. For a parameter
262 -- restriction, the Count and Unknown arrays have additional
265 Count : Restriction_Values := (others => 0);
266 -- If an entry for a parameter restriction is True in Violated,
267 -- the corresponding entry in the Count array may record additional
268 -- information. If the actual minimum count is known (by taking
269 -- maximums, or sums, depending on the restriction), it will be
270 -- recorded in this array. If not, then the value will remain zero.
272 Unknown : Parameter_Flags := (others => False);
273 -- If an entry for a parameter restriction is True in Violated,
274 -- the corresponding entry in the Unknown array may record additional
275 -- information. If the actual count is not known by the compiler (but
276 -- is known to be non-zero), then the entry in Unknown will be True.
277 -- This indicates that the value in Count is not known to be exact,
278 -- and the actual violation count may be higher.
280 -- Note: If Violated (K) is True, then either Count (K) > 0 or
281 -- Unknown (K) = True. It is possible for both these to be set.
282 -- For example, if Count (K) = 3 and Unknown (K) is True, it means
283 -- that the actual violation count is at least 3 but might be higher.
286 ----------------------------------
287 -- Profile Definitions and Data --
288 ----------------------------------
290 type Profile_Name is (Ravenscar, Restricted);
291 -- Names of recognized pfofiles
293 type Profile_Data is record
294 Set : Restriction_Flags;
295 -- Set to True if given restriction must be set for the profile,
296 -- and False if it need not be set (False does not mean that it
297 -- must not be set, just that it need not be set). If the flag
298 -- is True for a parameter restriction, then the Value array
299 -- gives the maximum value permitted by the profile.
301 Value : Restriction_Values;
302 -- An entry in this array is meaningful only if the corresponding
303 -- flag in Set is True. In that case, the value in this array is
304 -- the maximum value of the parameter permitted by the profile.
307 Profile_Info : array (Profile_Name) of Profile_Data :=
309 -- Restricted Profile
313 -- Restrictions for Restricted profile
316 (No_Abort_Statements => True,
317 No_Asynchronous_Control => True,
318 No_Dynamic_Attachment => True,
319 No_Dynamic_Priorities => True,
320 No_Entry_Queue => True,
321 No_Local_Protected_Objects => True,
322 No_Protected_Type_Allocators => True,
323 No_Requeue_Statements => True,
324 No_Task_Allocators => True,
325 No_Task_Attributes_Package => True,
326 No_Task_Hierarchy => True,
327 No_Terminate_Alternatives => True,
328 Max_Asynchronous_Select_Nesting => True,
329 Max_Protected_Entries => True,
330 Max_Select_Alternatives => True,
331 Max_Task_Entries => True,
334 -- Value settings for Restricted profile
337 (Max_Asynchronous_Select_Nesting => 0,
338 Max_Protected_Entries => 1,
339 Max_Select_Alternatives => 0,
340 Max_Task_Entries => 0,
345 -- Note: the table entries here only represent the
346 -- required restriction profile for Ravenscar. The
347 -- full Ravenscar profile also requires:
349 -- pragma Dispatching_Policy (FIFO_Within_Priorities);
350 -- pragma Locking_Policy (Ceiling_Locking);
351 -- pragma Detect_Blocking_Mode ???
355 -- Restrictions for Ravenscar = Restricted profile ..
358 (No_Abort_Statements => True,
359 No_Asynchronous_Control => True,
360 No_Dynamic_Attachment => True,
361 No_Dynamic_Priorities => True,
362 No_Entry_Queue => True,
363 No_Local_Protected_Objects => True,
364 No_Protected_Type_Allocators => True,
365 No_Requeue_Statements => True,
366 No_Task_Allocators => True,
367 No_Task_Attributes_Package => True,
368 No_Task_Hierarchy => True,
369 No_Terminate_Alternatives => True,
370 Max_Asynchronous_Select_Nesting => True,
371 Max_Protected_Entries => True,
372 Max_Select_Alternatives => True,
373 Max_Task_Entries => True,
375 -- plus these additional restrictions:
378 No_Implicit_Heap_Allocations => True,
379 No_Relative_Delay => True,
380 No_Select_Statements => True,
381 No_Task_Termination => True,
382 Simple_Barriers => True,
385 -- Value settings for Ravenscar (same as Restricted)
388 (Max_Asynchronous_Select_Nesting => 0,
389 Max_Protected_Entries => 1,
390 Max_Select_Alternatives => 0,
391 Max_Task_Entries => 0,
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