Imported Upstream version 4.8.1
[platform/upstream/gcc48.git] / gcc / ada / aspects.ads
1 ------------------------------------------------------------------------------
2 --                                                                          --
3 --                         GNAT COMPILER COMPONENTS                         --
4 --                                                                          --
5 --                              A S P E C T S                               --
6 --                                                                          --
7 --                                 S p e c                                  --
8 --                                                                          --
9 --          Copyright (C) 2010-2012, 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 aspects that are recognized by GNAT in aspect
33 --  specifications. It also contains the subprograms for storing/retrieving
34 --  aspect specifications from the tree. The semantic processing for aspect
35 --  specifications is found in Sem_Ch13.Analyze_Aspect_Specifications.
36
37 ------------------------
38 -- Adding New Aspects --
39 ------------------------
40
41 --  In general, each aspect should have a corresponding pragma, so that the
42 --  newly developed functionality is available for Ada versions < Ada 2012.
43 --  When both are defined, it is convenient to first transform the aspect into
44 --  an equivalent pragma in Sem_Ch13.Analyze_Aspect_Specifications, and then
45 --  analyze the pragma in Sem_Prag.Analyze_Pragma.
46
47 --  To add a new aspect, you need to do the following
48
49 --    1. Create a name in snames.ads-tmpl
50
51 --    2. Create a value in type Aspect_Id in this unit
52
53 --    3. Add a value for the aspect in the global arrays defined in this unit
54
55 --    4. Add code for the aspect in Sem_Ch13.Analyze_Aspect_Specifications.
56 --       This may involve adding some nodes to the tree to perform additional
57 --       treatments later.
58
59 --    5. If the semantic analysis of expressions/names in the aspect should not
60 --       occur at the point the aspect is defined, add code in the adequate
61 --       semantic analysis procedure for the aspect. For example, this is the
62 --       case for aspects Pre and Post on subprograms, which are pre-analyzed
63 --       at the end of the declaration list to which the subprogram belongs,
64 --       and fully analyzed (possibly with expansion) during the semantic
65 --       analysis of subprogram bodies.
66
67 with Namet;  use Namet;
68 with Snames; use Snames;
69 with Types;  use Types;
70
71 package Aspects is
72
73    --  Type defining recognized aspects
74
75    type Aspect_Id is
76      (No_Aspect,                            -- Dummy entry for no aspect
77       Aspect_Abstract_State,                -- GNAT
78       Aspect_Address,
79       Aspect_Alignment,
80       Aspect_Attach_Handler,
81       Aspect_Bit_Order,
82       Aspect_Component_Size,
83       Aspect_Constant_Indexing,
84       Aspect_Contract_Case,                 -- GNAT
85       Aspect_Contract_Cases,                -- GNAT
86       Aspect_Convention,
87       Aspect_CPU,
88       Aspect_Default_Component_Value,
89       Aspect_Default_Iterator,
90       Aspect_Default_Value,
91       Aspect_Dimension,                     -- GNAT
92       Aspect_Dimension_System,              -- GNAT
93       Aspect_Dispatching_Domain,
94       Aspect_Dynamic_Predicate,
95       Aspect_External_Name,
96       Aspect_External_Tag,
97       Aspect_Global,                        -- GNAT
98       Aspect_Implicit_Dereference,
99       Aspect_Input,
100       Aspect_Interrupt_Priority,
101       Aspect_Invariant,                     -- GNAT
102       Aspect_Iterator_Element,
103       Aspect_Link_Name,
104       Aspect_Machine_Radix,
105       Aspect_Object_Size,                   -- GNAT
106       Aspect_Output,
107       Aspect_Post,
108       Aspect_Postcondition,
109       Aspect_Pre,
110       Aspect_Precondition,
111       Aspect_Predicate,                     -- GNAT
112       Aspect_Priority,
113       Aspect_Read,
114       Aspect_Relative_Deadline,
115       Aspect_Scalar_Storage_Order,          -- GNAT
116       Aspect_Simple_Storage_Pool,           -- GNAT
117       Aspect_Size,
118       Aspect_Small,
119       Aspect_Static_Predicate,
120       Aspect_Storage_Pool,
121       Aspect_Storage_Size,
122       Aspect_Stream_Size,
123       Aspect_Suppress,
124       Aspect_Synchronization,
125       Aspect_Test_Case,                     -- GNAT
126       Aspect_Type_Invariant,
127       Aspect_Unsuppress,
128       Aspect_Value_Size,                    -- GNAT
129       Aspect_Variable_Indexing,
130       Aspect_Warnings,                      -- GNAT
131       Aspect_Write,
132
133       --  The following aspects correspond to library unit pragmas
134
135       Aspect_All_Calls_Remote,
136       Aspect_Compiler_Unit,                 -- GNAT
137       Aspect_Elaborate_Body,
138       Aspect_Preelaborate,
139       Aspect_Preelaborate_05,               -- GNAT
140       Aspect_Pure,
141       Aspect_Pure_05,                       -- GNAT
142       Aspect_Pure_12,                       -- GNAT
143       Aspect_Remote_Call_Interface,
144       Aspect_Remote_Types,
145       Aspect_Shared_Passive,
146       Aspect_Universal_Data,                -- GNAT
147
148       --  Remaining aspects have a static boolean value that turns the aspect
149       --  on or off. They all correspond to pragmas, but are only converted to
150       --  the pragmas where the value is True. A value of False normally means
151       --  that the aspect is ignored, except in the case of derived types where
152       --  the aspect value is inherited from the parent, in which case, we do
153       --  not allow False if we inherit a True value from the parent.
154
155       Aspect_Ada_2005,                      -- GNAT
156       Aspect_Ada_2012,                      -- GNAT
157       Aspect_Asynchronous,
158       Aspect_Atomic,
159       Aspect_Atomic_Components,
160       Aspect_Discard_Names,
161       Aspect_Export,
162       Aspect_Favor_Top_Level,               -- GNAT
163       Aspect_Independent,
164       Aspect_Independent_Components,
165       Aspect_Import,
166       Aspect_Inline,
167       Aspect_Inline_Always,                 -- GNAT
168       Aspect_Interrupt_Handler,
169       Aspect_No_Return,
170       Aspect_Pack,
171       Aspect_Persistent_BSS,                -- GNAT
172       Aspect_Preelaborable_Initialization,
173       Aspect_Pure_Function,                 -- GNAT
174       Aspect_Remote_Access_Type,            -- GNAT
175       Aspect_Shared,                        -- GNAT (equivalent to Atomic)
176       Aspect_Simple_Storage_Pool_Type,      -- GNAT
177       Aspect_Suppress_Debug_Info,           -- GNAT
178       Aspect_Unchecked_Union,
179       Aspect_Universal_Aliasing,            -- GNAT
180       Aspect_Unmodified,                    -- GNAT
181       Aspect_Unreferenced,                  -- GNAT
182       Aspect_Unreferenced_Objects,          -- GNAT
183       Aspect_Volatile,
184       Aspect_Volatile_Components,
185
186       --  Aspects that have a static boolean value but don't correspond to
187       --  pragmas
188
189       Aspect_Lock_Free);
190
191    subtype Aspect_Id_Exclude_No_Aspect is
192      Aspect_Id range Aspect_Id'Succ (No_Aspect) .. Aspect_Id'Last;
193    --  Aspect_Id's excluding No_Aspect
194
195    --  The following array indicates aspects that accept 'Class
196
197    Class_Aspect_OK : constant array (Aspect_Id) of Boolean :=
198                        (Aspect_Invariant      => True,
199                         Aspect_Pre            => True,
200                         Aspect_Predicate      => True,
201                         Aspect_Post           => True,
202                         Aspect_Type_Invariant => True,
203                         others                => False);
204
205    --  The following array indicates aspects that a subtype inherits from
206    --  its base type. True means that the subtype inherits the aspect from
207    --  its base type. False means it is not inherited.
208
209    Base_Aspect : constant array (Aspect_Id) of Boolean :=
210                    (Aspect_Atomic                  => True,
211                     Aspect_Atomic_Components       => True,
212                     Aspect_Discard_Names           => True,
213                     Aspect_Independent_Components  => True,
214                     Aspect_Iterator_Element        => True,
215                     Aspect_Constant_Indexing       => True,
216                     Aspect_Default_Iterator        => True,
217                     Aspect_Type_Invariant          => True,
218                     Aspect_Unchecked_Union         => True,
219                     Aspect_Variable_Indexing       => True,
220                     Aspect_Volatile                => True,
221                     others                         => False);
222
223    --  The following array identifies all implementation defined aspects
224
225    Impl_Defined_Aspects : constant array (Aspect_Id) of Boolean :=
226                             (Aspect_Abstract_State           => True,
227                              Aspect_Ada_2005                 => True,
228                              Aspect_Ada_2012                 => True,
229                              Aspect_Compiler_Unit            => True,
230                              Aspect_Contract_Case            => True,
231                              Aspect_Contract_Cases           => True,
232                              Aspect_Dimension                => True,
233                              Aspect_Dimension_System         => True,
234                              Aspect_Favor_Top_Level          => True,
235                              Aspect_Global                   => True,
236                              Aspect_Inline_Always            => True,
237                              Aspect_Invariant                => True,
238                              Aspect_Lock_Free                => True,
239                              Aspect_Object_Size              => True,
240                              Aspect_Persistent_BSS           => True,
241                              Aspect_Predicate                => True,
242                              Aspect_Preelaborate_05          => True,
243                              Aspect_Pure_05                  => True,
244                              Aspect_Pure_12                  => True,
245                              Aspect_Pure_Function            => True,
246                              Aspect_Remote_Access_Type       => True,
247                              Aspect_Scalar_Storage_Order     => True,
248                              Aspect_Shared                   => True,
249                              Aspect_Simple_Storage_Pool      => True,
250                              Aspect_Simple_Storage_Pool_Type => True,
251                              Aspect_Suppress_Debug_Info      => True,
252                              Aspect_Test_Case                => True,
253                              Aspect_Universal_Aliasing       => True,
254                              Aspect_Universal_Data           => True,
255                              Aspect_Unmodified               => True,
256                              Aspect_Unreferenced             => True,
257                              Aspect_Unreferenced_Objects     => True,
258                              Aspect_Value_Size               => True,
259                              Aspect_Warnings                 => True,
260                              others                          => False);
261
262    --  The following array indicates aspects for which multiple occurrences of
263    --  the same aspect attached to the same declaration are allowed.
264
265    No_Duplicates_Allowed : constant array (Aspect_Id) of Boolean :=
266                              (Aspect_Contract_Case  => False,
267                               Aspect_Test_Case      => False,
268                               others                => True);
269
270    --  The following array indicates type aspects that are inherited and apply
271    --  to the class-wide type as well.
272
273    Inherited_Aspect : constant array (Aspect_Id) of Boolean :=
274                         (Aspect_Constant_Indexing    => True,
275                          Aspect_Default_Iterator     => True,
276                          Aspect_Implicit_Dereference => True,
277                          Aspect_Iterator_Element     => True,
278                          Aspect_Remote_Types         => True,
279                          Aspect_Variable_Indexing    => True,
280                          others                      => False);
281
282    --  The following subtype defines aspects corresponding to library unit
283    --  pragmas, these can only validly appear as aspects for library units,
284    --  and result in a corresponding pragma being inserted immediately after
285    --  the occurrence of the aspect.
286
287    subtype Library_Unit_Aspects is
288      Aspect_Id range Aspect_All_Calls_Remote .. Aspect_Universal_Data;
289
290    --  The following subtype defines aspects accepting an optional static
291    --  boolean parameter indicating if the aspect should be active or
292    --  cancelling. If the parameter is missing the effective value is True,
293    --  enabling the aspect. If the parameter is present it must be a static
294    --  expression of type Standard.Boolean. If the value is True, then the
295    --  aspect is enabled. If it is False, the aspect is disabled.
296
297    subtype Boolean_Aspects is
298      Aspect_Id range Aspect_Ada_2005 .. Aspect_Id'Last;
299
300    subtype Pre_Post_Aspects is
301      Aspect_Id range Aspect_Post .. Aspect_Precondition;
302
303    --  The following type is used for indicating allowed expression forms
304
305    type Aspect_Expression is
306      (Optional,               -- Optional boolean expression
307       Expression,             -- Required expression
308       Name);                  -- Required name
309
310    --  The following array indicates what argument type is required
311
312    Aspect_Argument : constant array (Aspect_Id) of Aspect_Expression :=
313                        (No_Aspect                      => Optional,
314                         Aspect_Abstract_State          => Expression,
315                         Aspect_Address                 => Expression,
316                         Aspect_Alignment               => Expression,
317                         Aspect_Attach_Handler          => Expression,
318                         Aspect_Bit_Order               => Expression,
319                         Aspect_Component_Size          => Expression,
320                         Aspect_Constant_Indexing       => Name,
321                         Aspect_Contract_Case           => Expression,
322                         Aspect_Contract_Cases          => Expression,
323                         Aspect_Convention              => Name,
324                         Aspect_CPU                     => Expression,
325                         Aspect_Default_Component_Value => Expression,
326                         Aspect_Default_Iterator        => Name,
327                         Aspect_Default_Value           => Expression,
328                         Aspect_Dimension               => Expression,
329                         Aspect_Dimension_System        => Expression,
330                         Aspect_Dispatching_Domain      => Expression,
331                         Aspect_Dynamic_Predicate       => Expression,
332                         Aspect_External_Name           => Expression,
333                         Aspect_External_Tag            => Expression,
334                         Aspect_Global                  => Expression,
335                         Aspect_Implicit_Dereference    => Name,
336                         Aspect_Input                   => Name,
337                         Aspect_Interrupt_Priority      => Expression,
338                         Aspect_Invariant               => Expression,
339                         Aspect_Iterator_Element        => Name,
340                         Aspect_Link_Name               => Expression,
341                         Aspect_Machine_Radix           => Expression,
342                         Aspect_Object_Size             => Expression,
343                         Aspect_Output                  => Name,
344                         Aspect_Post                    => Expression,
345                         Aspect_Postcondition           => Expression,
346                         Aspect_Pre                     => Expression,
347                         Aspect_Precondition            => Expression,
348                         Aspect_Predicate               => Expression,
349                         Aspect_Priority                => Expression,
350                         Aspect_Read                    => Name,
351                         Aspect_Relative_Deadline       => Expression,
352                         Aspect_Scalar_Storage_Order    => Expression,
353                         Aspect_Simple_Storage_Pool     => Name,
354                         Aspect_Size                    => Expression,
355                         Aspect_Small                   => Expression,
356                         Aspect_Static_Predicate        => Expression,
357                         Aspect_Storage_Pool            => Name,
358                         Aspect_Storage_Size            => Expression,
359                         Aspect_Stream_Size             => Expression,
360                         Aspect_Suppress                => Name,
361                         Aspect_Synchronization         => Name,
362                         Aspect_Test_Case               => Expression,
363                         Aspect_Type_Invariant          => Expression,
364                         Aspect_Unsuppress              => Name,
365                         Aspect_Value_Size              => Expression,
366                         Aspect_Variable_Indexing       => Name,
367                         Aspect_Warnings                => Name,
368                         Aspect_Write                   => Name,
369
370                         Library_Unit_Aspects           => Optional,
371                         Boolean_Aspects                => Optional);
372
373    -----------------------------------------
374    -- Table Linking Names and Aspect_Id's --
375    -----------------------------------------
376
377    --  Table linking aspect names and id's
378
379    Aspect_Names : constant array (Aspect_Id) of Name_Id := (
380      No_Aspect                           => No_Name,
381      Aspect_Abstract_State               => Name_Abstract_State,
382      Aspect_Ada_2005                     => Name_Ada_2005,
383      Aspect_Ada_2012                     => Name_Ada_2012,
384      Aspect_Address                      => Name_Address,
385      Aspect_Alignment                    => Name_Alignment,
386      Aspect_All_Calls_Remote             => Name_All_Calls_Remote,
387      Aspect_Asynchronous                 => Name_Asynchronous,
388      Aspect_Atomic                       => Name_Atomic,
389      Aspect_Atomic_Components            => Name_Atomic_Components,
390      Aspect_Attach_Handler               => Name_Attach_Handler,
391      Aspect_Bit_Order                    => Name_Bit_Order,
392      Aspect_Compiler_Unit                => Name_Compiler_Unit,
393      Aspect_Component_Size               => Name_Component_Size,
394      Aspect_Constant_Indexing            => Name_Constant_Indexing,
395      Aspect_Contract_Case                => Name_Contract_Case,
396      Aspect_Contract_Cases               => Name_Contract_Cases,
397      Aspect_Convention                   => Name_Convention,
398      Aspect_CPU                          => Name_CPU,
399      Aspect_Default_Iterator             => Name_Default_Iterator,
400      Aspect_Default_Value                => Name_Default_Value,
401      Aspect_Default_Component_Value      => Name_Default_Component_Value,
402      Aspect_Dimension                    => Name_Dimension,
403      Aspect_Dimension_System             => Name_Dimension_System,
404      Aspect_Discard_Names                => Name_Discard_Names,
405      Aspect_Dispatching_Domain           => Name_Dispatching_Domain,
406      Aspect_Dynamic_Predicate            => Name_Dynamic_Predicate,
407      Aspect_Elaborate_Body               => Name_Elaborate_Body,
408      Aspect_External_Name                => Name_External_Name,
409      Aspect_External_Tag                 => Name_External_Tag,
410      Aspect_Export                       => Name_Export,
411      Aspect_Favor_Top_Level              => Name_Favor_Top_Level,
412      Aspect_Global                       => Name_Global,
413      Aspect_Implicit_Dereference         => Name_Implicit_Dereference,
414      Aspect_Import                       => Name_Import,
415      Aspect_Independent                  => Name_Independent,
416      Aspect_Independent_Components       => Name_Independent_Components,
417      Aspect_Inline                       => Name_Inline,
418      Aspect_Inline_Always                => Name_Inline_Always,
419      Aspect_Input                        => Name_Input,
420      Aspect_Interrupt_Handler            => Name_Interrupt_Handler,
421      Aspect_Interrupt_Priority           => Name_Interrupt_Priority,
422      Aspect_Invariant                    => Name_Invariant,
423      Aspect_Iterator_Element             => Name_Iterator_Element,
424      Aspect_Link_Name                    => Name_Link_Name,
425      Aspect_Lock_Free                    => Name_Lock_Free,
426      Aspect_Machine_Radix                => Name_Machine_Radix,
427      Aspect_No_Return                    => Name_No_Return,
428      Aspect_Object_Size                  => Name_Object_Size,
429      Aspect_Output                       => Name_Output,
430      Aspect_Pack                         => Name_Pack,
431      Aspect_Persistent_BSS               => Name_Persistent_BSS,
432      Aspect_Post                         => Name_Post,
433      Aspect_Postcondition                => Name_Postcondition,
434      Aspect_Pre                          => Name_Pre,
435      Aspect_Precondition                 => Name_Precondition,
436      Aspect_Predicate                    => Name_Predicate,
437      Aspect_Preelaborable_Initialization => Name_Preelaborable_Initialization,
438      Aspect_Preelaborate                 => Name_Preelaborate,
439      Aspect_Preelaborate_05              => Name_Preelaborate_05,
440      Aspect_Priority                     => Name_Priority,
441      Aspect_Pure                         => Name_Pure,
442      Aspect_Pure_05                      => Name_Pure_05,
443      Aspect_Pure_12                      => Name_Pure_12,
444      Aspect_Pure_Function                => Name_Pure_Function,
445      Aspect_Read                         => Name_Read,
446      Aspect_Relative_Deadline            => Name_Relative_Deadline,
447      Aspect_Remote_Access_Type           => Name_Remote_Access_Type,
448      Aspect_Remote_Call_Interface        => Name_Remote_Call_Interface,
449      Aspect_Remote_Types                 => Name_Remote_Types,
450      Aspect_Scalar_Storage_Order         => Name_Scalar_Storage_Order,
451      Aspect_Shared                       => Name_Shared,
452      Aspect_Shared_Passive               => Name_Shared_Passive,
453      Aspect_Simple_Storage_Pool          => Name_Simple_Storage_Pool,
454      Aspect_Simple_Storage_Pool_Type     => Name_Simple_Storage_Pool_Type,
455      Aspect_Size                         => Name_Size,
456      Aspect_Small                        => Name_Small,
457      Aspect_Static_Predicate             => Name_Static_Predicate,
458      Aspect_Storage_Pool                 => Name_Storage_Pool,
459      Aspect_Storage_Size                 => Name_Storage_Size,
460      Aspect_Stream_Size                  => Name_Stream_Size,
461      Aspect_Suppress                     => Name_Suppress,
462      Aspect_Suppress_Debug_Info          => Name_Suppress_Debug_Info,
463      Aspect_Synchronization              => Name_Synchronization,
464      Aspect_Test_Case                    => Name_Test_Case,
465      Aspect_Type_Invariant               => Name_Type_Invariant,
466      Aspect_Unchecked_Union              => Name_Unchecked_Union,
467      Aspect_Universal_Aliasing           => Name_Universal_Aliasing,
468      Aspect_Universal_Data               => Name_Universal_Data,
469      Aspect_Unmodified                   => Name_Unmodified,
470      Aspect_Unreferenced                 => Name_Unreferenced,
471      Aspect_Unreferenced_Objects         => Name_Unreferenced_Objects,
472      Aspect_Unsuppress                   => Name_Unsuppress,
473      Aspect_Value_Size                   => Name_Value_Size,
474      Aspect_Variable_Indexing            => Name_Variable_Indexing,
475      Aspect_Volatile                     => Name_Volatile,
476      Aspect_Volatile_Components          => Name_Volatile_Components,
477      Aspect_Warnings                     => Name_Warnings,
478      Aspect_Write                        => Name_Write);
479
480    function Get_Aspect_Id (Name : Name_Id) return Aspect_Id;
481    pragma Inline (Get_Aspect_Id);
482    --  Given a name Nam, returns the corresponding aspect id value. If the name
483    --  does not match any aspect, then No_Aspect is returned as the result.
484
485    ---------------------------------------------------
486    -- Handling of Aspect Specifications in the Tree --
487    ---------------------------------------------------
488
489    --  Several kinds of declaration node permit aspect specifications in Ada
490    --  2012 mode. If there was room in all the corresponding declaration nodes,
491    --  we could just have a field Aspect_Specifications pointing to a list of
492    --  nodes for the aspects (N_Aspect_Specification nodes). But there isn't
493    --  room, so we adopt a different approach.
494
495    --  The following subprograms provide access to a specialized interface
496    --  implemented internally with a hash table in the body, that provides
497    --  access to aspect specifications.
498
499    function Permits_Aspect_Specifications (N : Node_Id) return Boolean;
500    --  Returns True if the node N is a declaration node that permits aspect
501    --  specifications in the grammar. It is possible for other nodes to have
502    --  aspect specifications as a result of Rewrite or Replace calls.
503
504    function Aspect_Specifications (N : Node_Id) return List_Id;
505    --  Given a node N, returns the list of N_Aspect_Specification nodes that
506    --  are attached to this declaration node. If the node is in the class of
507    --  declaration nodes that permit aspect specifications, as defined by the
508    --  predicate above, and if their Has_Aspects flag is set to True, then this
509    --  will always be a non-empty list. If this flag is set to False, then
510    --  No_List is returned. Normally, the only nodes that have Has_Aspects set
511    --  True are the nodes for which Permits_Aspect_Specifications would return
512    --  True (i.e. the declaration nodes defined in the RM as permitting the
513    --  presence of Aspect_Specifications). However, it is possible for the
514    --  flag Has_Aspects to be set on other nodes as a result of Rewrite and
515    --  Replace calls, and this function may be used to retrieve the aspect
516    --  specifications for the original rewritten node in such cases.
517
518    procedure Set_Aspect_Specifications (N : Node_Id; L : List_Id);
519    --  The node N must be in the class of declaration nodes that permit aspect
520    --  specifications and the Has_Aspects flag must be False on entry. L must
521    --  be a non-empty list of N_Aspect_Specification nodes. This procedure sets
522    --  the Has_Aspects flag to True, and makes an entry that can be retrieved
523    --  by a subsequent Aspect_Specifications call. It is an error to call this
524    --  procedure with a node that does not permit aspect specifications, or a
525    --  node that has its Has_Aspects flag set True on entry, or with L being an
526    --  empty list or No_List.
527
528    function Find_Aspect (Ent : Entity_Id; A : Aspect_Id) return Node_Id;
529    --  Find value of a given aspect from aspect list of entity
530
531    procedure Move_Aspects (From : Node_Id; To : Node_Id);
532    --  Moves aspects from 'From' node to 'To' node. Has_Aspects (To) must be
533    --  False on entry. If Has_Aspects (From) is False, the call has no effect.
534    --  Otherwise the aspects are moved and on return Has_Aspects (To) is True,
535    --  and Has_Aspects (From) is False.
536
537    function Same_Aspect (A1 : Aspect_Id; A2 : Aspect_Id) return Boolean;
538    --  Returns True if A1 and A2 are (essentially) the same aspect. This is not
539    --  a simple equality test because e.g. Post and Postcondition are the same.
540    --  This is used for detecting duplicate aspects.
541
542    procedure Tree_Write;
543    --  Writes contents of Aspect_Specifications hash table to the tree file
544
545    procedure Tree_Read;
546    --  Reads contents of Aspect_Specifications hash table from the tree file
547
548 end Aspects;