1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . R I D E N T --
9 -- Copyright (C) 1992-2006, 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, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, 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
50 -- The following enumeration type defines the set of restriction
51 -- identifiers that are implemented in GNAT.
53 -- To add a new restriction identifier, add an entry with the name
54 -- to be used in the pragma, and add appropriate calls to the
55 -- Restrict.Check_Restriction routine.
57 type Restriction_Id is
59 -- The following cases are checked for consistency in the binder
61 (Simple_Barriers, -- GNAT (Ravenscar)
62 No_Abort_Statements, -- (RM D.7(5), H.4(3))
63 No_Access_Subprograms, -- (RM H.4(17))
64 No_Allocators, -- (RM H.4(7))
65 No_Asynchronous_Control, -- (RM D.7(10))
67 No_Delay, -- (RM H.4(21))
68 No_Direct_Boolean_Operators, -- GNAT
69 No_Dispatch, -- (RM H.4(19))
70 No_Dispatching_Calls, -- GNAT
71 No_Dynamic_Attachment, -- GNAT
72 No_Dynamic_Priorities, -- (RM D.9(9))
73 No_Enumeration_Maps, -- GNAT
74 No_Entry_Calls_In_Elaboration_Code, -- GNAT
75 No_Entry_Queue, -- GNAT (Ravenscar)
76 No_Exception_Handlers, -- GNAT
77 No_Exception_Propagation, -- GNAT
78 No_Exception_Registration, -- GNAT
79 No_Exceptions, -- (RM H.4(12))
80 No_Finalization, -- GNAT
81 No_Fixed_Point, -- (RM H.4(15))
82 No_Floating_Point, -- (RM H.4(14))
83 No_IO, -- (RM H.4(20))
84 No_Implicit_Conditionals, -- GNAT
85 No_Implicit_Dynamic_Code, -- GNAT
86 No_Implicit_Heap_Allocations, -- (RM D.8(8), H.4(3))
87 No_Implicit_Loops, -- GNAT
88 No_Initialize_Scalars, -- GNAT
89 No_Local_Allocators, -- (RM H.4(8))
90 No_Local_Protected_Objects, -- GNAT
91 No_Nested_Finalization, -- (RM D.7(4))
92 No_Protected_Type_Allocators, -- GNAT
93 No_Protected_Types, -- (RM H.4(5))
94 No_Recursion, -- (RM H.4(22))
95 No_Reentrancy, -- (RM H.4(23))
96 No_Relative_Delay, -- GNAT (Ravenscar)
97 No_Requeue_Statements, -- GNAT
98 No_Secondary_Stack, -- GNAT
99 No_Select_Statements, -- GNAT (Ravenscar)
100 No_Standard_Storage_Pools, -- GNAT
102 No_Task_Allocators, -- (RM D.7(7))
103 No_Task_Attributes_Package, -- GNAT
104 No_Task_Hierarchy, -- (RM D.7(3), H.4(3))
105 No_Task_Termination, -- GNAT (Ravenscar)
107 No_Terminate_Alternatives, -- (RM D.7(6))
108 No_Unchecked_Access, -- (RM H.4(18))
109 No_Unchecked_Conversion, -- (RM H.4(16))
110 No_Unchecked_Deallocation, -- (RM H.4(9))
111 Static_Priorities, -- GNAT
112 Static_Storage_Size, -- GNAT
114 -- The following cases do not require partition-wide checks
116 Immediate_Reclamation, -- (RM H.4(10))
117 No_Implementation_Attributes, -- Ada 2005 AI-257
118 No_Implementation_Pragmas, -- Ada 2005 AI-257
119 No_Implementation_Restrictions, -- GNAT
120 No_Elaboration_Code, -- GNAT
121 No_Obsolescent_Features, -- Ada 2005 AI-368
122 No_Wide_Characters, -- GNAT
124 -- The following cases require a parameter value
126 -- The following entries are fully checked at compile/bind time,
127 -- which means that the compiler can in general tell the minimum
128 -- value which could be used with a restrictions pragma. The binder
129 -- can deduce the appropriate minimum value for the partition by
130 -- taking the maximum value required by any unit.
132 Max_Protected_Entries, -- (RM D.7(14))
133 Max_Select_Alternatives, -- (RM D.7(12))
134 Max_Task_Entries, -- (RM D.7(13), H.4(3))
136 -- The following entries are also fully checked at compile/bind
137 -- time, and the compiler can also at least in some cases tell
138 -- the minimum value which could be used with a restriction pragma.
139 -- The difference is that the contributions are additive, so the
140 -- binder deduces this value by adding the unit contributions.
142 Max_Tasks, -- (RM D.7(19), H.4(3))
144 -- The following entries are checked at compile time only for
145 -- zero/nonzero entries. This means that the compiler can tell
146 -- at compile time if a restriction value of zero is (would be)
147 -- violated, but that is all. The compiler cannot distinguish
148 -- between different non-zero values.
150 Max_Asynchronous_Select_Nesting, -- (RM D.7(18), H.4(3))
151 Max_Entry_Queue_Length, -- GNAT
153 -- The remaining entries are not checked at compile/bind time
155 Max_Storage_At_Blocking, -- (RM D.7(17))
157 Not_A_Restriction_Id);
159 -- Synonyms permitted for historical purposes of compatibility.
160 -- Must be coordinated with Restrict.Process_Restriction_Synonym.
162 Boolean_Entry_Barriers : Restriction_Id renames Simple_Barriers;
163 Max_Entry_Queue_Depth : Restriction_Id renames Max_Entry_Queue_Length;
164 No_Dynamic_Interrupts : Restriction_Id renames No_Dynamic_Attachment;
165 No_Requeue : Restriction_Id renames No_Requeue_Statements;
166 No_Task_Attributes : Restriction_Id renames No_Task_Attributes_Package;
168 subtype All_Restrictions is Restriction_Id range
169 Simple_Barriers .. Max_Storage_At_Blocking;
170 -- All restrictions (excluding only Not_A_Restriction_Id)
172 subtype All_Boolean_Restrictions is Restriction_Id range
173 Simple_Barriers .. No_Wide_Characters;
174 -- All restrictions which do not take a parameter
176 subtype Partition_Boolean_Restrictions is All_Boolean_Restrictions range
177 Simple_Barriers .. Static_Storage_Size;
178 -- Boolean restrictions that are checked for partition consistency.
179 -- Note that all parameter restrictions are checked for partition
180 -- consistency by default, so this distinction is only needed in the
181 -- case of Boolean restrictions.
183 subtype Cunit_Boolean_Restrictions is All_Boolean_Restrictions range
184 Immediate_Reclamation .. No_Wide_Characters;
185 -- Boolean restrictions that are not checked for partition consistency
186 -- and that thus apply only to the current unit. Note that for these
187 -- restrictions, the compiler does not apply restrictions found in
188 -- with'ed units, parent specs etc to the main unit.
190 subtype All_Parameter_Restrictions is
192 Max_Protected_Entries .. Max_Storage_At_Blocking;
193 -- All restrictions that are take a parameter
195 subtype Checked_Parameter_Restrictions is
196 All_Parameter_Restrictions range
197 Max_Protected_Entries .. Max_Entry_Queue_Length;
198 -- These are the parameter restrictions that can be at least partially
199 -- checked at compile/binder time. Minimally, the compiler can detect
200 -- violations of a restriction pragma with a value of zero reliably.
202 subtype Checked_Max_Parameter_Restrictions is
203 Checked_Parameter_Restrictions range
204 Max_Protected_Entries .. Max_Task_Entries;
205 -- Restrictions with parameters that can be checked in some cases by
206 -- maximizing among statically detected instances where the compiler
207 -- can determine the count.
209 subtype Checked_Add_Parameter_Restrictions is
210 Checked_Parameter_Restrictions range
211 Max_Tasks .. Max_Tasks;
212 -- Restrictions with parameters that can be checked in some cases by
213 -- summing the statically detected instances where the compiler can
214 -- determine the count.
216 subtype Checked_Val_Parameter_Restrictions is
217 Checked_Parameter_Restrictions range
218 Max_Protected_Entries .. Max_Tasks;
219 -- Restrictions with parameter where the count is known at least in
220 -- some cases by the compiler/binder.
222 subtype Checked_Zero_Parameter_Restrictions is
223 Checked_Parameter_Restrictions range
224 Max_Asynchronous_Select_Nesting .. Max_Entry_Queue_Length;
225 -- Restrictions with parameters where the compiler can detect the use of
226 -- the feature, and hence violations of a restriction specifying a value
227 -- of zero, but cannot detect specific values other than zero/nonzero.
229 subtype Unchecked_Parameter_Restrictions is
230 All_Parameter_Restrictions range
231 Max_Storage_At_Blocking .. Max_Storage_At_Blocking;
232 -- Restrictions with parameters where the compiler cannot ever detect
233 -- corresponding compile time usage, so the binder and compiler never
234 -- detect violations of any restriction.
236 -------------------------------------
237 -- Restriction Status Declarations --
238 -------------------------------------
240 -- The following declarations are used to record the current status
241 -- or restrictions (for the current unit, or related units, at compile
242 -- time, and for all units in a partition at bind time or run time).
244 type Restriction_Flags is array (All_Restrictions) of Boolean;
245 type Restriction_Values is array (All_Parameter_Restrictions) of Natural;
246 type Parameter_Flags is array (All_Parameter_Restrictions) of Boolean;
248 type Restrictions_Info is record
249 Set : Restriction_Flags;
250 -- An entry is True in the Set array if a restrictions pragma has
251 -- been encountered for the given restriction. If the value is
252 -- True for a parameter restriction, then the corresponding entry
253 -- in the Value array gives the minimum value encountered for any
256 Value : Restriction_Values;
257 -- If the entry for a parameter restriction in Set is True (i.e. a
258 -- restrictions pragma for the restriction has been encountered), then
259 -- the corresponding entry in the Value array is the minimum value
260 -- specified by any such restrictions pragma. Note that a restrictions
261 -- pragma specifying a value greater than Int'Last is simply ignored.
263 Violated : Restriction_Flags;
264 -- An entry is True in the violations array if the compiler has
265 -- detected a violation of the restriction. For a parameter
266 -- restriction, the Count and Unknown arrays have additional
269 Count : Restriction_Values;
270 -- If an entry for a parameter restriction is True in Violated,
271 -- the corresponding entry in the Count array may record additional
272 -- information. If the actual minimum count is known (by taking
273 -- maximums, or sums, depending on the restriction), it will be
274 -- recorded in this array. If not, then the value will remain zero.
276 Unknown : Parameter_Flags;
277 -- If an entry for a parameter restriction is True in Violated,
278 -- the corresponding entry in the Unknown array may record additional
279 -- information. If the actual count is not known by the compiler (but
280 -- is known to be non-zero), then the entry in Unknown will be True.
281 -- This indicates that the value in Count is not known to be exact,
282 -- and the actual violation count may be higher.
284 -- Note: If Violated (K) is True, then either Count (K) > 0 or
285 -- Unknown (K) = True. It is possible for both these to be set.
286 -- For example, if Count (K) = 3 and Unknown (K) is True, it means
287 -- that the actual violation count is at least 3 but might be higher.
290 No_Restrictions : constant Restrictions_Info :=
291 (Set => (others => False),
292 Value => (others => 0),
293 Violated => (others => False),
294 Count => (others => 0),
295 Unknown => (others => False));
296 -- Used to initialize Restrictions_Info variables
298 ----------------------------------
299 -- Profile Definitions and Data --
300 ----------------------------------
302 type Profile_Name is (Ravenscar, Restricted);
303 -- Names of recognized pfofiles
305 type Profile_Data is record
306 Set : Restriction_Flags;
307 -- Set to True if given restriction must be set for the profile,
308 -- and False if it need not be set (False does not mean that it
309 -- must not be set, just that it need not be set). If the flag
310 -- is True for a parameter restriction, then the Value array
311 -- gives the maximum value permitted by the profile.
313 Value : Restriction_Values;
314 -- An entry in this array is meaningful only if the corresponding
315 -- flag in Set is True. In that case, the value in this array is
316 -- the maximum value of the parameter permitted by the profile.
319 Profile_Info : array (Profile_Name) of Profile_Data :=
321 -- Restricted Profile
325 -- Restrictions for Restricted profile
328 (No_Abort_Statements => True,
329 No_Asynchronous_Control => True,
330 No_Dynamic_Attachment => True,
331 No_Dynamic_Priorities => True,
332 No_Entry_Queue => True,
333 No_Local_Protected_Objects => True,
334 No_Protected_Type_Allocators => True,
335 No_Requeue_Statements => True,
336 No_Task_Allocators => True,
337 No_Task_Attributes_Package => True,
338 No_Task_Hierarchy => True,
339 No_Terminate_Alternatives => True,
340 Max_Asynchronous_Select_Nesting => True,
341 Max_Protected_Entries => True,
342 Max_Select_Alternatives => True,
343 Max_Task_Entries => True,
346 -- Value settings for Restricted profile
349 (Max_Asynchronous_Select_Nesting => 0,
350 Max_Protected_Entries => 1,
351 Max_Select_Alternatives => 0,
352 Max_Task_Entries => 0,
357 -- Note: the table entries here only represent the
358 -- required restriction profile for Ravenscar. The
359 -- full Ravenscar profile also requires:
361 -- pragma Dispatching_Policy (FIFO_Within_Priorities);
362 -- pragma Locking_Policy (Ceiling_Locking);
363 -- pragma Detect_Blocking
367 -- Restrictions for Ravenscar = Restricted profile ..
370 (No_Abort_Statements => True,
371 No_Asynchronous_Control => True,
372 No_Dynamic_Attachment => True,
373 No_Dynamic_Priorities => True,
374 No_Entry_Queue => True,
375 No_Local_Protected_Objects => True,
376 No_Protected_Type_Allocators => True,
377 No_Requeue_Statements => True,
378 No_Task_Allocators => True,
379 No_Task_Attributes_Package => True,
380 No_Task_Hierarchy => True,
381 No_Terminate_Alternatives => True,
382 Max_Asynchronous_Select_Nesting => True,
383 Max_Protected_Entries => True,
384 Max_Select_Alternatives => True,
385 Max_Task_Entries => True,
387 -- plus these additional restrictions:
390 No_Implicit_Heap_Allocations => True,
391 No_Relative_Delay => True,
392 No_Select_Statements => True,
393 No_Task_Termination => True,
394 Simple_Barriers => True,
397 -- Value settings for Ravenscar (same as Restricted)
400 (Max_Asynchronous_Select_Nesting => 0,
401 Max_Protected_Entries => 1,
402 Max_Select_Alternatives => 0,
403 Max_Task_Entries => 0,