1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . R I D E N T --
9 -- Copyright (C) 1992-2008, 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. The
60 -- binder will check that every unit either has the restriction set, or
61 -- does not violate the restriction.
63 (Simple_Barriers, -- GNAT (Ravenscar)
64 No_Abort_Statements, -- (RM D.7(5), H.4(3))
65 No_Access_Subprograms, -- (RM H.4(17))
66 No_Allocators, -- (RM H.4(7))
67 No_Asynchronous_Control, -- (RM D.7(10))
69 No_Delay, -- (RM H.4(21))
70 No_Direct_Boolean_Operators, -- GNAT
71 No_Dispatch, -- (RM H.4(19))
72 No_Dispatching_Calls, -- GNAT
73 No_Dynamic_Attachment, -- GNAT
74 No_Dynamic_Priorities, -- (RM D.9(9))
75 No_Enumeration_Maps, -- GNAT
76 No_Entry_Calls_In_Elaboration_Code, -- GNAT
77 No_Entry_Queue, -- GNAT (Ravenscar)
78 No_Exception_Handlers, -- GNAT
79 No_Exception_Propagation, -- GNAT
80 No_Exception_Registration, -- GNAT
81 No_Exceptions, -- (RM H.4(12))
82 No_Finalization, -- GNAT
83 No_Fixed_Point, -- (RM H.4(15))
84 No_Floating_Point, -- (RM H.4(14))
85 No_IO, -- (RM H.4(20))
86 No_Implicit_Conditionals, -- GNAT
87 No_Implicit_Dynamic_Code, -- GNAT
88 No_Implicit_Heap_Allocations, -- (RM D.8(8), H.4(3))
89 No_Implicit_Loops, -- GNAT
90 No_Initialize_Scalars, -- GNAT
91 No_Local_Allocators, -- (RM H.4(8))
92 No_Local_Protected_Objects, -- GNAT
93 No_Nested_Finalization, -- (RM D.7(4))
94 No_Protected_Type_Allocators, -- GNAT
95 No_Protected_Types, -- (RM H.4(5))
96 No_Recursion, -- (RM H.4(22))
97 No_Reentrancy, -- (RM H.4(23))
98 No_Relative_Delay, -- GNAT (Ravenscar)
99 No_Requeue_Statements, -- GNAT
100 No_Secondary_Stack, -- GNAT
101 No_Select_Statements, -- GNAT (Ravenscar)
102 No_Standard_Storage_Pools, -- GNAT
104 No_Task_Allocators, -- (RM D.7(7))
105 No_Task_Attributes_Package, -- GNAT
106 No_Task_Hierarchy, -- (RM D.7(3), H.4(3))
107 No_Task_Termination, -- GNAT (Ravenscar)
109 No_Terminate_Alternatives, -- (RM D.7(6))
110 No_Unchecked_Access, -- (RM H.4(18))
111 No_Unchecked_Conversion, -- (RM H.4(16))
112 No_Unchecked_Deallocation, -- (RM H.4(9))
113 Static_Priorities, -- GNAT
114 Static_Storage_Size, -- GNAT
116 -- The following require consistency checking with special rules. See
117 -- individual routines in unit Bcheck for details of what is required.
119 No_Default_Initialization, -- GNAT
121 -- The following cases do not require consistency checking
123 Immediate_Reclamation, -- (RM H.4(10))
124 No_Implementation_Attributes, -- Ada 2005 AI-257
125 No_Implementation_Pragmas, -- Ada 2005 AI-257
126 No_Implementation_Restrictions, -- GNAT
127 No_Elaboration_Code, -- GNAT
128 No_Obsolescent_Features, -- Ada 2005 AI-368
129 No_Wide_Characters, -- GNAT
131 -- The following cases require a parameter value
133 -- The following entries are fully checked at compile/bind time, which
134 -- means that the compiler can in general tell the minimum value which
135 -- could be used with a restrictions pragma. The binder can deduce the
136 -- appropriate minimum value for the partition by taking the maximum
137 -- value required by any unit.
139 Max_Protected_Entries, -- (RM D.7(14))
140 Max_Select_Alternatives, -- (RM D.7(12))
141 Max_Task_Entries, -- (RM D.7(13), H.4(3))
143 -- The following entries are also fully checked at compile/bind time,
144 -- and the compiler can also at least in some cases tell the minimum
145 -- value which could be used with a restriction pragma. The difference
146 -- is that the contributions are additive, so the binder deduces this
147 -- value by adding the unit contributions.
149 Max_Tasks, -- (RM D.7(19), H.4(3))
151 -- The following entries are checked at compile time only for zero/
152 -- nonzero entries. This means that the compiler can tell at compile
153 -- time if a restriction value of zero is (would be) violated, but that
154 -- the compiler cannot distinguish between different non-zero values.
156 Max_Asynchronous_Select_Nesting, -- (RM D.7(18), H.4(3))
157 Max_Entry_Queue_Length, -- GNAT
159 -- The remaining entries are not checked at compile/bind time
161 Max_Storage_At_Blocking, -- (RM D.7(17))
163 Not_A_Restriction_Id);
165 -- Synonyms permitted for historical purposes of compatibility.
166 -- Must be coordinated with Restrict.Process_Restriction_Synonym.
168 Boolean_Entry_Barriers : Restriction_Id renames Simple_Barriers;
169 Max_Entry_Queue_Depth : Restriction_Id renames Max_Entry_Queue_Length;
170 No_Dynamic_Interrupts : Restriction_Id renames No_Dynamic_Attachment;
171 No_Requeue : Restriction_Id renames No_Requeue_Statements;
172 No_Task_Attributes : Restriction_Id renames No_Task_Attributes_Package;
174 subtype All_Restrictions is Restriction_Id range
175 Simple_Barriers .. Max_Storage_At_Blocking;
176 -- All restrictions (excluding only Not_A_Restriction_Id)
178 subtype All_Boolean_Restrictions is Restriction_Id range
179 Simple_Barriers .. No_Wide_Characters;
180 -- All restrictions which do not take a parameter
182 subtype Partition_Boolean_Restrictions is All_Boolean_Restrictions range
183 Simple_Barriers .. Static_Storage_Size;
184 -- Boolean restrictions that are checked for partition consistency.
185 -- Note that all parameter restrictions are checked for partition
186 -- consistency by default, so this distinction is only needed in the
187 -- case of Boolean restrictions.
189 subtype Cunit_Boolean_Restrictions is All_Boolean_Restrictions range
190 Immediate_Reclamation .. No_Wide_Characters;
191 -- Boolean restrictions that are not checked for partition consistency
192 -- and that thus apply only to the current unit. Note that for these
193 -- restrictions, the compiler does not apply restrictions found in
194 -- with'ed units, parent specs etc to the main unit.
196 subtype All_Parameter_Restrictions is
198 Max_Protected_Entries .. Max_Storage_At_Blocking;
199 -- All restrictions that are take a parameter
201 subtype Checked_Parameter_Restrictions is
202 All_Parameter_Restrictions range
203 Max_Protected_Entries .. Max_Entry_Queue_Length;
204 -- These are the parameter restrictions that can be at least partially
205 -- checked at compile/binder time. Minimally, the compiler can detect
206 -- violations of a restriction pragma with a value of zero reliably.
208 subtype Checked_Max_Parameter_Restrictions is
209 Checked_Parameter_Restrictions range
210 Max_Protected_Entries .. Max_Task_Entries;
211 -- Restrictions with parameters that can be checked in some cases by
212 -- maximizing among statically detected instances where the compiler
213 -- can determine the count.
215 subtype Checked_Add_Parameter_Restrictions is
216 Checked_Parameter_Restrictions range
217 Max_Tasks .. Max_Tasks;
218 -- Restrictions with parameters that can be checked in some cases by
219 -- summing the statically detected instances where the compiler can
220 -- determine the count.
222 subtype Checked_Val_Parameter_Restrictions is
223 Checked_Parameter_Restrictions range
224 Max_Protected_Entries .. Max_Tasks;
225 -- Restrictions with parameter where the count is known at least in
226 -- some cases by the compiler/binder.
228 subtype Checked_Zero_Parameter_Restrictions is
229 Checked_Parameter_Restrictions range
230 Max_Asynchronous_Select_Nesting .. Max_Entry_Queue_Length;
231 -- Restrictions with parameters where the compiler can detect the use of
232 -- the feature, and hence violations of a restriction specifying a value
233 -- of zero, but cannot detect specific values other than zero/nonzero.
235 subtype Unchecked_Parameter_Restrictions is
236 All_Parameter_Restrictions range
237 Max_Storage_At_Blocking .. Max_Storage_At_Blocking;
238 -- Restrictions with parameters where the compiler cannot ever detect
239 -- corresponding compile time usage, so the binder and compiler never
240 -- detect violations of any restriction.
242 -------------------------------------
243 -- Restriction Status Declarations --
244 -------------------------------------
246 -- The following declarations are used to record the current status or
247 -- restrictions (for the current unit, or related units, at compile time,
248 -- and for all units in a partition at bind time or run time).
250 type Restriction_Flags is array (All_Restrictions) of Boolean;
251 type Restriction_Values is array (All_Parameter_Restrictions) of Natural;
252 type Parameter_Flags is array (All_Parameter_Restrictions) of Boolean;
254 type Restrictions_Info is record
255 Set : Restriction_Flags;
256 -- An entry is True in the Set array if a restrictions pragma has been
257 -- encountered for the given restriction. If the value is True for a
258 -- parameter restriction, then the corresponding entry in the Value
259 -- array gives the minimum value encountered for any such restriction.
261 Value : Restriction_Values;
262 -- If the entry for a parameter restriction in Set is True (i.e. a
263 -- restrictions pragma for the restriction has been encountered), then
264 -- the corresponding entry in the Value array is the minimum value
265 -- specified by any such restrictions pragma. Note that a restrictions
266 -- pragma specifying a value greater than Int'Last is simply ignored.
268 Violated : Restriction_Flags;
269 -- An entry is True in the violations array if the compiler has detected
270 -- a violation of the restriction. For a parameter restriction, the
271 -- Count and Unknown arrays have additional information.
273 Count : Restriction_Values;
274 -- If an entry for a parameter restriction is True in Violated, the
275 -- corresponding entry in the Count array may record additional
276 -- information. If the actual minimum count is known (by taking
277 -- maximums, or sums, depending on the restriction), it will be
278 -- recorded in this array. If not, then the value will remain zero.
279 -- The value is also zero for a non-violated restriction.
281 Unknown : Parameter_Flags;
282 -- If an entry for a parameter restriction is True in Violated, the
283 -- corresponding entry in the Unknown array may record additional
284 -- information. If the actual count is not known by the compiler (but
285 -- is nown to be non-zero), then the entry in Unknown will be True.
286 -- This indicates that the value in Count is not known to be exact,
287 -- and the actual violation count may be higher.
289 -- Note: If Violated (K) is True, then either Count (K) > 0 or
290 -- Unknown (K) = True. It is possible for both these to be set.
291 -- For example, if Count (K) = 3 and Unknown (K) is True, it means
292 -- that the actual violation count is at least 3 but might be higher.
295 No_Restrictions : constant Restrictions_Info :=
296 (Set => (others => False),
297 Value => (others => 0),
298 Violated => (others => False),
299 Count => (others => 0),
300 Unknown => (others => False));
301 -- Used to initialize Restrictions_Info variables
303 ----------------------------------
304 -- Profile Definitions and Data --
305 ----------------------------------
307 type Profile_Name is (Ravenscar, Restricted);
308 -- Names of recognized pfofiles
310 type Profile_Data is record
311 Set : Restriction_Flags;
312 -- Set to True if given restriction must be set for the profile,
313 -- and False if it need not be set (False does not mean that it
314 -- must not be set, just that it need not be set). If the flag
315 -- is True for a parameter restriction, then the Value array
316 -- gives the maximum value permitted by the profile.
318 Value : Restriction_Values;
319 -- An entry in this array is meaningful only if the corresponding
320 -- flag in Set is True. In that case, the value in this array is
321 -- the maximum value of the parameter permitted by the profile.
324 Profile_Info : array (Profile_Name) of Profile_Data :=
326 -- Restricted Profile
330 -- Restrictions for Restricted profile
333 (No_Abort_Statements => True,
334 No_Asynchronous_Control => True,
335 No_Dynamic_Attachment => True,
336 No_Dynamic_Priorities => True,
337 No_Entry_Queue => True,
338 No_Local_Protected_Objects => True,
339 No_Protected_Type_Allocators => True,
340 No_Requeue_Statements => True,
341 No_Task_Allocators => True,
342 No_Task_Attributes_Package => True,
343 No_Task_Hierarchy => True,
344 No_Terminate_Alternatives => True,
345 Max_Asynchronous_Select_Nesting => True,
346 Max_Protected_Entries => True,
347 Max_Select_Alternatives => True,
348 Max_Task_Entries => True,
351 -- Value settings for Restricted profile
354 (Max_Asynchronous_Select_Nesting => 0,
355 Max_Protected_Entries => 1,
356 Max_Select_Alternatives => 0,
357 Max_Task_Entries => 0,
362 -- Note: the table entries here only represent the
363 -- required restriction profile for Ravenscar. The
364 -- full Ravenscar profile also requires:
366 -- pragma Dispatching_Policy (FIFO_Within_Priorities);
367 -- pragma Locking_Policy (Ceiling_Locking);
368 -- pragma Detect_Blocking
372 -- Restrictions for Ravenscar = Restricted profile ..
375 (No_Abort_Statements => True,
376 No_Asynchronous_Control => True,
377 No_Dynamic_Attachment => True,
378 No_Dynamic_Priorities => True,
379 No_Entry_Queue => True,
380 No_Local_Protected_Objects => True,
381 No_Protected_Type_Allocators => True,
382 No_Requeue_Statements => True,
383 No_Task_Allocators => True,
384 No_Task_Attributes_Package => True,
385 No_Task_Hierarchy => True,
386 No_Terminate_Alternatives => True,
387 Max_Asynchronous_Select_Nesting => True,
388 Max_Protected_Entries => True,
389 Max_Select_Alternatives => True,
390 Max_Task_Entries => True,
392 -- plus these additional restrictions:
395 No_Implicit_Heap_Allocations => True,
396 No_Relative_Delay => True,
397 No_Select_Statements => True,
398 No_Task_Termination => True,
399 Simple_Barriers => True,
402 -- Value settings for Ravenscar (same as Restricted)
405 (Max_Asynchronous_Select_Nesting => 0,
406 Max_Protected_Entries => 1,
407 Max_Select_Alternatives => 0,
408 Max_Task_Entries => 0,