gcc/ada/s-rident.ads

   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) 1992-2011, 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 pragma Compiler_Unit;
  45
  46 generic
  47 package System.Rident is
  48    pragma Preelaborate;
  49
  50    --  The following enumeration type defines the set of restriction
  51    --  identifiers that are implemented in GNAT.
  52
  53    --  To add a new restriction identifier, add an entry with the name to be
  54    --  used in the pragma, and add calls to the Restrict.Check_Restriction
  55    --  routine as appropriate.
  56
  57    type Restriction_Id is
  58
  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.
  62
  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_Allocators_After_Elaboration,         -- Ada 2012 (RM D.7(19.1/2))
  68       No_Anonymous_Allocators,                 -- Ada 2012 (RM H.4(8/1))
  69       No_Asynchronous_Control,                 -- (RM D.7(10))
  70       No_Calendar,                             -- GNAT
  71       No_Default_Stream_Attributes,            -- Ada 2012 (RM 13.12.1(4/2))
  72       No_Delay,                                -- (RM H.4(21))
  73       No_Direct_Boolean_Operators,             -- GNAT
  74       No_Dispatch,                             -- (RM H.4(19))
  75       No_Dispatching_Calls,                    -- GNAT
  76       No_Dynamic_Attachment,                   -- GNAT
  77       No_Dynamic_Priorities,                   -- (RM D.9(9))
  78       No_Enumeration_Maps,                     -- GNAT
  79       No_Entry_Calls_In_Elaboration_Code,      -- GNAT
  80       No_Entry_Queue,                          -- GNAT (Ravenscar)
  81       No_Exception_Handlers,                   -- GNAT
  82       No_Exception_Propagation,                -- GNAT
  83       No_Exception_Registration,               -- GNAT
  84       No_Exceptions,                           -- (RM H.4(12))
  85       No_Finalization,                         -- GNAT
  86       No_Fixed_Point,                          -- (RM H.4(15))
  87       No_Floating_Point,                       -- (RM H.4(14))
  88       No_IO,                                   -- (RM H.4(20))
  89       No_Implicit_Conditionals,                -- GNAT
  90       No_Implicit_Dynamic_Code,                -- GNAT
  91       No_Implicit_Heap_Allocations,            -- (RM D.8(8), H.4(3))
  92       No_Implicit_Loops,                       -- GNAT
  93       No_Initialize_Scalars,                   -- GNAT
  94       No_Local_Allocators,                     -- (RM H.4(8))
  95       No_Local_Timing_Events,                  -- (RM D.7(10.2/2))
  96       No_Local_Protected_Objects,              -- GNAT
  97       No_Nested_Finalization,                  -- (RM D.7(4))
  98       No_Protected_Type_Allocators,            -- GNAT
  99       No_Protected_Types,                      -- (RM H.4(5))
 100       No_Recursion,                            -- (RM H.4(22))
 101       No_Reentrancy,                           -- (RM H.4(23))
 102       No_Relative_Delay,                       -- GNAT (Ravenscar)
 103       No_Requeue_Statements,                   -- GNAT
 104       No_Secondary_Stack,                      -- GNAT
 105       No_Select_Statements,                    -- GNAT (Ravenscar)
 106       No_Specific_Termination_Handlers,        -- (RM D.7(10.7/2))
 107       No_Standard_Storage_Pools,               -- GNAT
 108       No_Stream_Optimizations,                 -- GNAT
 109       No_Streams,                              -- GNAT
 110       No_Task_Allocators,                      -- (RM D.7(7))
 111       No_Task_Attributes_Package,              -- GNAT
 112       No_Task_Hierarchy,                       -- (RM D.7(3), H.4(3))
 113       No_Task_Termination,                     -- GNAT (Ravenscar)
 114       No_Tasking,                              -- GNAT
 115       No_Terminate_Alternatives,               -- (RM D.7(6))
 116       No_Unchecked_Access,                     -- (RM H.4(18))
 117       No_Unchecked_Conversion,                 -- (RM H.4(16))
 118       No_Unchecked_Deallocation,               -- (RM H.4(9))
 119       Static_Priorities,                       -- GNAT
 120       Static_Storage_Size,                     -- GNAT
 121
 122       --  The following require consistency checking with special rules. See
 123       --  individual routines in unit Bcheck for details of what is required.
 124
 125       No_Default_Initialization,               -- GNAT
 126
 127       --  The following cases do not require consistency checking and if used
 128       --  as a configuration pragma within a specific unit, apply only to that
 129       --  unit (e.g. if used in the package spec, do not apply to the body)
 130
 131       --  Note: No_Elaboration_Code is handled specially. Like the other
 132       --  non-partition-wide restrictions, it can only be set in a unit that
 133       --  is part of the extended main source unit (body/spec/subunits). But
 134       --  it is sticky, in that if it is found anywhere within any of these
 135       --  units, it applies to all units in this extended main source.
 136
 137       Immediate_Reclamation,                   -- (RM H.4(10))
 138       No_Implementation_Aspect_Specifications, -- Ada 2012 AI-241
 139       No_Implementation_Attributes,            -- Ada 2005 AI-257
 140       No_Implementation_Identifiers,           -- Ada 2012 AI-246
 141       No_Implementation_Pragmas,               -- Ada 2005 AI-257
 142       No_Implementation_Restrictions,          -- GNAT
 143       No_Implementation_Units,                 -- Ada 2012 AI-242
 144       No_Implicit_Aliasing,                    -- GNAT
 145       No_Elaboration_Code,                     -- GNAT
 146       No_Obsolescent_Features,                 -- Ada 2005 AI-368
 147       No_Wide_Characters,                      -- GNAT
 148       SPARK,                                   -- GNAT
 149
 150       --  The following cases require a parameter value
 151
 152       --  The following entries are fully checked at compile/bind time, which
 153       --  means that the compiler can in general tell the minimum value which
 154       --  could be used with a restrictions pragma. The binder can deduce the
 155       --  appropriate minimum value for the partition by taking the maximum
 156       --  value required by any unit.
 157
 158       Max_Protected_Entries,                   -- (RM D.7(14))
 159       Max_Select_Alternatives,                 -- (RM D.7(12))
 160       Max_Task_Entries,                        -- (RM D.7(13), H.4(3))
 161
 162       --  The following entries are also fully checked at compile/bind time,
 163       --  and the compiler can also at least in some cases tell the minimum
 164       --  value which could be used with a restriction pragma. The difference
 165       --  is that the contributions are additive, so the binder deduces this
 166       --  value by adding the unit contributions.
 167
 168       Max_Tasks,                               -- (RM D.7(19), H.4(3))
 169
 170       --  The following entries are checked at compile time only for zero/
 171       --  nonzero entries. This means that the compiler can tell at compile
 172       --  time if a restriction value of zero is (would be) violated, but that
 173       --  the compiler cannot distinguish between different non-zero values.
 174
 175       Max_Asynchronous_Select_Nesting,         -- (RM D.7(18), H.4(3))
 176       Max_Entry_Queue_Length,                  -- GNAT
 177
 178       --  The remaining entries are not checked at compile/bind time
 179
 180       Max_Storage_At_Blocking,                 -- (RM D.7(17))
 181
 182       Not_A_Restriction_Id);
 183
 184    --  Synonyms permitted for historical purposes of compatibility.
 185    --  Must be coordinated with Restrict.Process_Restriction_Synonym.
 186
 187    Boolean_Entry_Barriers : Restriction_Id renames Simple_Barriers;
 188    Max_Entry_Queue_Depth  : Restriction_Id renames Max_Entry_Queue_Length;
 189    No_Dynamic_Interrupts  : Restriction_Id renames No_Dynamic_Attachment;
 190    No_Requeue             : Restriction_Id renames No_Requeue_Statements;
 191    No_Task_Attributes     : Restriction_Id renames No_Task_Attributes_Package;
 192
 193    subtype All_Restrictions is Restriction_Id range
 194      Simple_Barriers .. Max_Storage_At_Blocking;
 195    --  All restrictions (excluding only Not_A_Restriction_Id)
 196
 197    subtype All_Boolean_Restrictions is Restriction_Id range
 198      Simple_Barriers .. SPARK;
 199    --  All restrictions which do not take a parameter
 200
 201    subtype Partition_Boolean_Restrictions is All_Boolean_Restrictions range
 202      Simple_Barriers .. Static_Storage_Size;
 203    --  Boolean restrictions that are checked for partition consistency.
 204    --  Note that all parameter restrictions are checked for partition
 205    --  consistency by default, so this distinction is only needed in the
 206    --  case of Boolean restrictions.
 207
 208    subtype Cunit_Boolean_Restrictions is All_Boolean_Restrictions range
 209      Immediate_Reclamation .. SPARK;
 210    --  Boolean restrictions that are not checked for partition consistency
 211    --  and that thus apply only to the current unit. Note that for these
 212    --  restrictions, the compiler does not apply restrictions found in
 213    --  with'ed units, parent specs etc. to the main unit, and vice versa.
 214
 215    subtype All_Parameter_Restrictions is
 216      Restriction_Id range
 217        Max_Protected_Entries .. Max_Storage_At_Blocking;
 218    --  All restrictions that take a parameter
 219
 220    subtype Checked_Parameter_Restrictions is
 221      All_Parameter_Restrictions range
 222        Max_Protected_Entries .. Max_Entry_Queue_Length;
 223    --  These are the parameter restrictions that can be at least partially
 224    --  checked at compile/binder time. Minimally, the compiler can detect
 225    --  violations of a restriction pragma with a value of zero reliably.
 226
 227    subtype Checked_Max_Parameter_Restrictions is
 228      Checked_Parameter_Restrictions range
 229        Max_Protected_Entries .. Max_Task_Entries;
 230    --  Restrictions with parameters that can be checked in some cases by
 231    --  maximizing among statically detected instances where the compiler
 232    --  can determine the count.
 233
 234    subtype Checked_Add_Parameter_Restrictions is
 235      Checked_Parameter_Restrictions range
 236        Max_Tasks .. Max_Tasks;
 237    --  Restrictions with parameters that can be checked in some cases by
 238    --  summing the statically detected instances where the compiler can
 239    --  determine the count.
 240
 241    subtype Checked_Val_Parameter_Restrictions is
 242      Checked_Parameter_Restrictions range
 243        Max_Protected_Entries .. Max_Tasks;
 244    --  Restrictions with parameter where the count is known at least in some
 245    --  cases by the compiler/binder.
 246
 247    subtype Checked_Zero_Parameter_Restrictions is
 248      Checked_Parameter_Restrictions range
 249        Max_Asynchronous_Select_Nesting .. Max_Entry_Queue_Length;
 250    --  Restrictions with parameters where the compiler can detect the use of
 251    --  the feature, and hence violations of a restriction specifying a value
 252    --  of zero, but cannot detect specific values other than zero/nonzero.
 253
 254    subtype Unchecked_Parameter_Restrictions is
 255      All_Parameter_Restrictions range
 256        Max_Storage_At_Blocking .. Max_Storage_At_Blocking;
 257    --  Restrictions with parameters where the compiler cannot ever detect
 258    --  corresponding compile time usage, so the binder and compiler never
 259    --  detect violations of any restriction.
 260
 261    -------------------------------------
 262    -- Restriction Status Declarations --
 263    -------------------------------------
 264
 265    --  The following declarations are used to record the current status or
 266    --  restrictions (for the current unit, or related units, at compile time,
 267    --  and for all units in a partition at bind time or run time).
 268
 269    type Restriction_Flags  is array (All_Restrictions)           of Boolean;
 270    type Restriction_Values is array (All_Parameter_Restrictions) of Natural;
 271    type Parameter_Flags    is array (All_Parameter_Restrictions) of Boolean;
 272
 273    type Restrictions_Info is record
 274       Set : Restriction_Flags;
 275       --  An entry is True in the Set array if a restrictions pragma has been
 276       --  encountered for the given restriction. If the value is True for a
 277       --  parameter restriction, then the corresponding entry in the Value
 278       --  array gives the minimum value encountered for any such restriction.
 279
 280       Value : Restriction_Values;
 281       --  If the entry for a parameter restriction in Set is True (i.e. a
 282       --  restrictions pragma for the restriction has been encountered), then
 283       --  the corresponding entry in the Value array is the minimum value
 284       --  specified by any such restrictions pragma. Note that a restrictions
 285       --  pragma specifying a value greater than Int'Last is simply ignored.
 286
 287       Violated : Restriction_Flags;
 288       --  An entry is True in the violations array if the compiler has detected
 289       --  a violation of the restriction. For a parameter restriction, the
 290       --  Count and Unknown arrays have additional information.
 291
 292       Count : Restriction_Values;
 293       --  If an entry for a parameter restriction is True in Violated, the
 294       --  corresponding entry in the Count array may record additional
 295       --  information. If the actual minimum count is known (by taking
 296       --  maximums, or sums, depending on the restriction), it will be
 297       --  recorded in this array. If not, then the value will remain zero.
 298       --  The value is also zero for a non-violated restriction.
 299
 300       Unknown : Parameter_Flags;
 301       --  If an entry for a parameter restriction is True in Violated, the
 302       --  corresponding entry in the Unknown array may record additional
 303       --  information. If the actual count is not known by the compiler (but
 304       --  is known to be non-zero), then the entry in Unknown will be True.
 305       --  This indicates that the value in Count is not known to be exact,
 306       --  and the actual violation count may be higher.
 307
 308       --  Note: If Violated (K) is True, then either Count (K) > 0 or
 309       --  Unknown (K) = True. It is possible for both these to be set.
 310       --  For example, if Count (K) = 3 and Unknown (K) is True, it means
 311       --  that the actual violation count is at least 3 but might be higher.
 312    end record;
 313
 314    No_Restrictions : constant Restrictions_Info :=
 315      (Set      => (others => False),
 316       Value    => (others => 0),
 317       Violated => (others => False),
 318       Count    => (others => 0),
 319       Unknown  => (others => False));
 320    --  Used to initialize Restrictions_Info variables
 321
 322    ----------------------------------
 323    -- Profile Definitions and Data --
 324    ----------------------------------
 325
 326    --  Note: to add a profile, modify the following declarations appropriately,
 327    --  add Name_xxx to Snames, and add a branch to the conditions for pragmas
 328    --  Profile and Profile_Warnings in the body of Sem_Prag.
 329
 330    type Profile_Name is
 331      (No_Profile,
 332       No_Implementation_Extensions,
 333       Ravenscar,
 334       Restricted);
 335    --  Names of recognized profiles. No_Profile is used to indicate that a
 336    --  restriction came from pragma Restrictions[_Warning], as opposed to
 337    --  pragma Profile[_Warning].
 338
 339    subtype Profile_Name_Actual is Profile_Name
 340      range No_Implementation_Extensions .. Restricted;
 341    --  Actual used profile names
 342
 343    type Profile_Data is record
 344       Set : Restriction_Flags;
 345       --  Set to True if given restriction must be set for the profile, and
 346       --  False if it need not be set (False does not mean that it must not be
 347       --  set, just that it need not be set). If the flag is True for a
 348       --  parameter restriction, then the Value array gives the maximum value
 349       --  permitted by the profile.
 350
 351       Value : Restriction_Values;
 352       --  An entry in this array is meaningful only if the corresponding flag
 353       --  in Set is True. In that case, the value in this array is the maximum
 354       --  value of the parameter permitted by the profile.
 355    end record;
 356
 357    Profile_Info : constant array (Profile_Name_Actual) of Profile_Data :=
 358
 359                     (No_Implementation_Extensions =>
 360                         --  Restrictions for Restricted profile
 361
 362                        (Set   =>
 363                           (No_Implementation_Aspect_Specifications => True,
 364                            No_Implementation_Attributes            => True,
 365                            No_Implementation_Identifiers           => True,
 366                            No_Implementation_Pragmas               => True,
 367                            No_Implementation_Units                 => True,
 368                            others                                  => False),
 369
 370                         --  Value settings for Restricted profile (none
 371
 372                         Value =>
 373                           (others                          => 0)),
 374
 375                      --  Restricted Profile
 376
 377                      Restricted =>
 378
 379                         --  Restrictions for Restricted profile
 380
 381                        (Set   =>
 382                           (No_Abort_Statements             => True,
 383                            No_Asynchronous_Control         => True,
 384                            No_Dynamic_Attachment           => True,
 385                            No_Dynamic_Priorities           => True,
 386                            No_Entry_Queue                  => True,
 387                            No_Local_Protected_Objects      => True,
 388                            No_Protected_Type_Allocators    => True,
 389                            No_Requeue_Statements           => True,
 390                            No_Task_Allocators              => True,
 391                            No_Task_Attributes_Package      => True,
 392                            No_Task_Hierarchy               => True,
 393                            No_Terminate_Alternatives       => True,
 394                            Max_Asynchronous_Select_Nesting => True,
 395                            Max_Protected_Entries           => True,
 396                            Max_Select_Alternatives         => True,
 397                            Max_Task_Entries                => True,
 398                            others                          => False),
 399
 400                         --  Value settings for Restricted profile
 401
 402                         Value =>
 403                           (Max_Asynchronous_Select_Nesting => 0,
 404                            Max_Protected_Entries           => 1,
 405                            Max_Select_Alternatives         => 0,
 406                            Max_Task_Entries                => 0,
 407                            others                          => 0)),
 408
 409                      --  Ravenscar Profile
 410
 411                      --  Note: the table entries here only represent the
 412                      --  required restriction profile for Ravenscar. The
 413                      --  full Ravenscar profile also requires:
 414
 415                      --    pragma Dispatching_Policy (FIFO_Within_Priorities);
 416                      --    pragma Locking_Policy (Ceiling_Locking);
 417                      --    pragma Detect_Blocking
 418
 419                      Ravenscar  =>
 420
 421                      --  Restrictions for Ravenscar = Restricted profile ..
 422
 423                        (Set   =>
 424                           (No_Abort_Statements             => True,
 425                            No_Asynchronous_Control         => True,
 426                            No_Dynamic_Attachment           => True,
 427                            No_Dynamic_Priorities           => True,
 428                            No_Entry_Queue                  => True,
 429                            No_Local_Protected_Objects      => True,
 430                            No_Protected_Type_Allocators    => True,
 431                            No_Requeue_Statements           => True,
 432                            No_Task_Allocators              => True,
 433                            No_Task_Attributes_Package      => True,
 434                            No_Task_Hierarchy               => True,
 435                            No_Terminate_Alternatives       => True,
 436                            Max_Asynchronous_Select_Nesting => True,
 437                            Max_Protected_Entries           => True,
 438                            Max_Select_Alternatives         => True,
 439                            Max_Task_Entries                => True,
 440
 441                            --  plus these additional restrictions:
 442
 443                            No_Calendar                     => True,
 444                            No_Implicit_Heap_Allocations    => True,
 445                            No_Relative_Delay               => True,
 446                            No_Select_Statements            => True,
 447                            No_Task_Termination             => True,
 448                            Simple_Barriers                 => True,
 449                            others                          => False),
 450
 451                         --  Value settings for Ravenscar (same as Restricted)
 452
 453                         Value =>
 454                           (Max_Asynchronous_Select_Nesting => 0,
 455                            Max_Protected_Entries           => 1,
 456                            Max_Select_Alternatives         => 0,
 457                            Max_Task_Entries                => 0,
 458                            others                          => 0)));
 459
 460 end System.Rident;