1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2019, 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 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. 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 COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
32 with Namet; use Namet;
33 with Nlists; use Nlists;
36 with Sem_Attr; use Sem_Attr;
37 with Sem_Aux; use Sem_Aux;
38 with Sem_Dist; use Sem_Dist;
39 with Sem_Eval; use Sem_Eval;
40 with Sem_Util; use Sem_Util;
41 with Sinfo; use Sinfo;
42 with Snames; use Snames;
43 with Stand; use Stand;
45 package body Sem_Cat is
47 -----------------------
48 -- Local Subprograms --
49 -----------------------
51 procedure Check_Categorization_Dependencies
52 (Unit_Entity : Entity_Id;
53 Depended_Entity : Entity_Id;
55 Is_Subunit : Boolean);
56 -- This procedure checks that the categorization of a lib unit and that
57 -- of the depended unit satisfy dependency restrictions.
58 -- The depended_entity can be the entity in a with_clause item, in which
59 -- case Info_Node denotes that item. The depended_entity can also be the
60 -- parent unit of a child unit, in which case Info_Node is the declaration
61 -- of the child unit. The error message is posted on Info_Node, and is
62 -- specialized if Is_Subunit is true.
64 procedure Check_Non_Static_Default_Expr
67 -- Iterate through the component list of a record definition, check
68 -- that no component is declared with a nonstatic default value.
69 -- If a nonstatic default exists, report an error on Obj_Decl.
71 function Has_Read_Write_Attributes (E : Entity_Id) return Boolean;
72 -- Return True if entity has attribute definition clauses for Read and
73 -- Write attributes that are visible at some place.
75 function Is_Non_Remote_Access_Type (E : Entity_Id) return Boolean;
76 -- Returns true if the entity is a type whose full view is a non-remote
77 -- access type, for the purpose of enforcing E.2.2(8) rules.
79 function Has_Non_Remote_Access (Typ : Entity_Id) return Boolean;
80 -- Return true if Typ or the type of any of its subcomponents is a non
81 -- remote access type and doesn't have user-defined stream attributes.
83 function No_External_Streaming (E : Entity_Id) return Boolean;
84 -- Return True if the entity or one of its subcomponents does not support
85 -- external streaming.
87 function In_RCI_Declaration return Boolean;
88 function In_RT_Declaration return Boolean;
89 -- Determine if current scope is within the declaration of a Remote Call
90 -- Interface or Remote Types unit, for semantic checking purposes.
92 function In_Package_Declaration return Boolean;
93 -- Shared supporting routine for In_RCI_Declaration and In_RT_Declaration
95 function In_Shared_Passive_Unit return Boolean;
96 -- Determines if current scope is within a Shared Passive compilation unit
98 function Static_Discriminant_Expr (L : List_Id) return Boolean;
99 -- Iterate through the list of discriminants to check if any of them
100 -- contains non-static default expression, which is a violation in
101 -- a preelaborated library unit.
103 procedure Validate_Remote_Access_Object_Type_Declaration (T : Entity_Id);
104 -- Check validity of declaration if RCI or RT unit. It should not contain
105 -- the declaration of an access-to-object type unless it is a general
106 -- access type that designates a class-wide limited private type. There are
107 -- also constraints about the primitive subprograms of the class-wide type.
108 -- RM E.2 (9, 13, 14)
110 procedure Validate_RACW_Primitive
113 -- Check legality of the declaration of primitive Subp of the designated
114 -- type of the given RACW type.
116 ---------------------------------------
117 -- Check_Categorization_Dependencies --
118 ---------------------------------------
120 procedure Check_Categorization_Dependencies
121 (Unit_Entity : Entity_Id;
122 Depended_Entity : Entity_Id;
124 Is_Subunit : Boolean)
126 N : constant Node_Id := Info_Node;
129 -- Here we define an enumeration type to represent categorization types,
130 -- ordered so that a unit with a given categorization can only WITH
131 -- units with lower or equal categorization type.
133 type Categorization is
137 Remote_Call_Interface,
140 function Get_Categorization (E : Entity_Id) return Categorization;
141 -- Check categorization flags from entity, and return in the form
142 -- of the lowest value of the Categorization type that applies to E.
144 ------------------------
145 -- Get_Categorization --
146 ------------------------
148 function Get_Categorization (E : Entity_Id) return Categorization is
150 -- Get the lowest categorization that corresponds to E. Note that
151 -- nothing prevents several (different) categorization pragmas
152 -- to apply to the same library unit, in which case the unit has
153 -- all associated categories, so we need to be careful here to
154 -- check pragmas in proper Categorization order in order to
155 -- return the lowest applicable value.
157 -- Ignore Pure specification if set by pragma Pure_Function
161 (Has_Pragma_Pure_Function (E) and not Has_Pragma_Pure (E))
165 elsif Is_Shared_Passive (E) then
166 return Shared_Passive;
168 elsif Is_Remote_Types (E) then
171 elsif Is_Remote_Call_Interface (E) then
172 return Remote_Call_Interface;
177 end Get_Categorization;
179 Unit_Category : Categorization;
180 With_Category : Categorization;
182 -- Start of processing for Check_Categorization_Dependencies
185 -- Intrinsic subprograms are preelaborated, so do not impose any
186 -- categorization dependencies. Also, ignore categorization
187 -- dependencies when compilation switch -gnatdu is used.
189 if Is_Intrinsic_Subprogram (Depended_Entity) or else Debug_Flag_U then
193 -- First check 10.2.1 (11/1) rules on preelaborate packages
195 if Is_Preelaborated (Unit_Entity)
196 and then not Is_Preelaborated (Depended_Entity)
197 and then not Is_Pure (Depended_Entity)
204 -- Check categorization rules of RM E.2(5)
206 Unit_Category := Get_Categorization (Unit_Entity);
207 With_Category := Get_Categorization (Depended_Entity);
209 if With_Category > Unit_Category then
211 -- Special case: Remote_Types and Remote_Call_Interface are allowed
212 -- to WITH anything in the package body, per (RM E.2(5)).
214 if (Unit_Category = Remote_Types
215 or else Unit_Category = Remote_Call_Interface)
216 and then In_Package_Body (Unit_Entity)
220 -- Special case: Remote_Types and Remote_Call_Interface declarations
221 -- can depend on a preelaborated unit via a private with_clause, per
224 elsif (Unit_Category = Remote_Types
226 Unit_Category = Remote_Call_Interface)
227 and then Nkind (N) = N_With_Clause
228 and then Private_Present (N)
229 and then Is_Preelaborated (Depended_Entity)
233 -- All other cases, we do have an error
240 -- Here if we have an error
244 -- These messages are warnings in GNAT mode or if the -gnateP switch
245 -- was set. Otherwise these are real errors for real illegalities.
247 -- The reason we suppress these errors in GNAT mode is that the run-
248 -- time has several instances of violations of the categorization
249 -- errors (e.g. Pure units withing Preelaborate units. All these
250 -- violations are harmless in the cases where we intend them, and
251 -- we suppress the warnings with Warnings (Off). In cases where we
252 -- do not intend the violation, warnings are errors in GNAT mode
253 -- anyway, so we will still get an error.
256 Treat_Categorization_Errors_As_Warnings or GNAT_Mode;
258 -- Don't give error if main unit is not an internal unit, and the
259 -- unit generating the message is an internal unit. This is the
260 -- situation in which such messages would be ignored in any case,
261 -- so it is convenient not to generate them (since it causes
262 -- annoying interference with debugging).
264 if Is_Internal_Unit (Current_Sem_Unit)
265 and then not Is_Internal_Unit (Main_Unit)
269 -- Dependence of Remote_Types or Remote_Call_Interface declaration
270 -- on a preelaborated unit with a normal with_clause.
272 elsif (Unit_Category = Remote_Types
274 Unit_Category = Remote_Call_Interface)
275 and then Is_Preelaborated (Depended_Entity)
278 ("<<must use private with clause for preelaborated unit& ",
283 elsif Is_Subunit then
285 ("<subunit cannot depend on& " &
286 "(parent has wrong categorization)", N, Depended_Entity);
288 -- Normal unit, not subunit
292 ("<<cannot depend on& " &
293 "(wrong categorization)", N, Depended_Entity);
296 -- Add further explanation for Pure/Preelaborate common cases
298 if Unit_Category = Pure then
300 ("\<<pure unit cannot depend on non-pure unit",
303 elsif Is_Preelaborated (Unit_Entity)
304 and then not Is_Preelaborated (Depended_Entity)
305 and then not Is_Pure (Depended_Entity)
308 ("\<<preelaborated unit cannot depend on "
309 & "non-preelaborated unit",
313 end Check_Categorization_Dependencies;
315 -----------------------------------
316 -- Check_Non_Static_Default_Expr --
317 -----------------------------------
319 procedure Check_Non_Static_Default_Expr
324 Component_Decl : Node_Id;
327 if Nkind (Type_Def) = N_Derived_Type_Definition then
328 Recdef := Record_Extension_Part (Type_Def);
338 -- Check that component declarations do not involve:
340 -- a. a non-static default expression, where the object is
341 -- declared to be default initialized.
343 -- b. a dynamic Itype (discriminants and constraints)
345 if Null_Present (Recdef) then
348 Component_Decl := First (Component_Items (Component_List (Recdef)));
351 while Present (Component_Decl)
352 and then Nkind (Component_Decl) = N_Component_Declaration
354 if Present (Expression (Component_Decl))
355 and then Nkind (Expression (Component_Decl)) /= N_Null
356 and then not Is_OK_Static_Expression (Expression (Component_Decl))
358 Error_Msg_Sloc := Sloc (Component_Decl);
360 ("object in preelaborated unit has non-static default#",
363 -- Fix this later ???
365 -- elsif Has_Dynamic_Itype (Component_Decl) then
367 -- ("dynamic type discriminant," &
368 -- " constraint in preelaborated unit",
372 Next (Component_Decl);
374 end Check_Non_Static_Default_Expr;
376 ---------------------------
377 -- Has_Non_Remote_Access --
378 ---------------------------
380 function Has_Non_Remote_Access (Typ : Entity_Id) return Boolean is
381 Component : Entity_Id;
382 Comp_Type : Entity_Id;
383 U_Typ : constant Entity_Id := Underlying_Type (Typ);
389 elsif Has_Read_Write_Attributes (Typ)
390 or else Has_Read_Write_Attributes (U_Typ)
394 elsif Is_Non_Remote_Access_Type (U_Typ) then
398 if Is_Record_Type (U_Typ) then
399 Component := First_Entity (U_Typ);
400 while Present (Component) loop
401 if not Is_Tag (Component) then
402 Comp_Type := Etype (Component);
404 if Has_Non_Remote_Access (Comp_Type) then
409 Next_Entity (Component);
412 elsif Is_Array_Type (U_Typ) then
413 return Has_Non_Remote_Access (Component_Type (U_Typ));
418 end Has_Non_Remote_Access;
420 -------------------------------
421 -- Has_Read_Write_Attributes --
422 -------------------------------
424 function Has_Read_Write_Attributes (E : Entity_Id) return Boolean is
427 and then Has_Stream_Attribute_Definition
428 (E, TSS_Stream_Read, At_Any_Place => True)
429 and then Has_Stream_Attribute_Definition
430 (E, TSS_Stream_Write, At_Any_Place => True);
431 end Has_Read_Write_Attributes;
433 -------------------------------------
434 -- Has_Stream_Attribute_Definition --
435 -------------------------------------
437 function Has_Stream_Attribute_Definition
440 At_Any_Place : Boolean := False) return Boolean
445 -- The stream operation may be specified by an attribute definition
446 -- clause in the source, or by an aspect that generates such an
447 -- attribute definition. For an aspect, the generated attribute
448 -- definition may be placed at the freeze point of the full view of
449 -- the type, but the aspect specification makes the operation visible
450 -- to a client wherever the partial view is visible.
453 -- We start from the declaration node and then loop until the end of
454 -- the list until we find the requested attribute definition clause.
455 -- In Ada 2005 mode, clauses are ignored if they are not currently
456 -- visible (this is tested using the corresponding Entity, which is
457 -- inserted by the expander at the point where the clause occurs),
458 -- unless At_Any_Place is true.
460 Rep_Item := First_Rep_Item (Typ);
461 while Present (Rep_Item) loop
462 Real_Rep := Rep_Item;
464 -- If the representation item is an aspect specification, retrieve
465 -- the corresponding pragma or attribute definition.
467 if Nkind (Rep_Item) = N_Aspect_Specification then
468 Real_Rep := Aspect_Rep_Item (Rep_Item);
471 if Nkind (Real_Rep) = N_Attribute_Definition_Clause then
472 case Chars (Real_Rep) is
474 exit when Nam = TSS_Stream_Read;
477 exit when Nam = TSS_Stream_Write;
480 exit when Nam = TSS_Stream_Input;
483 exit when Nam = TSS_Stream_Output;
490 Next_Rep_Item (Rep_Item);
493 -- If not found, and the type is derived from a private view, check
494 -- for a stream attribute inherited from parent. Any specified stream
495 -- attributes will be attached to the derived type's underlying type
496 -- rather the derived type entity itself (which is itself private).
499 and then Is_Private_Type (Typ)
500 and then Is_Derived_Type (Typ)
501 and then Present (Full_View (Typ))
503 return Has_Stream_Attribute_Definition
504 (Underlying_Type (Typ), Nam, At_Any_Place);
506 -- Otherwise, if At_Any_Place is true, return True if the attribute is
507 -- available at any place; if it is false, return True only if the
508 -- attribute is currently visible.
511 return Present (Rep_Item)
512 and then (Ada_Version < Ada_2005
514 or else not Is_Hidden (Entity (Rep_Item)));
516 end Has_Stream_Attribute_Definition;
518 ----------------------------
519 -- In_Package_Declaration --
520 ----------------------------
522 function In_Package_Declaration return Boolean is
523 Unit_Kind : constant Node_Kind :=
524 Nkind (Unit (Cunit (Current_Sem_Unit)));
527 -- There are no restrictions on the body of an RCI or RT unit
529 return Is_Package_Or_Generic_Package (Current_Scope)
530 and then Unit_Kind /= N_Package_Body
531 and then not In_Package_Body (Current_Scope)
532 and then not In_Instance;
533 end In_Package_Declaration;
535 ---------------------------
536 -- In_Preelaborated_Unit --
537 ---------------------------
539 function In_Preelaborated_Unit return Boolean is
540 Unit_Entity : Entity_Id := Current_Scope;
541 Unit_Kind : constant Node_Kind :=
542 Nkind (Unit (Cunit (Current_Sem_Unit)));
545 -- If evaluating actuals for a child unit instantiation, then ignore
546 -- the preelaboration status of the parent; use the child instead.
548 if Is_Compilation_Unit (Unit_Entity)
549 and then Unit_Kind in N_Generic_Instantiation
550 and then not In_Same_Source_Unit (Unit_Entity,
551 Cunit (Current_Sem_Unit))
553 Unit_Entity := Cunit_Entity (Current_Sem_Unit);
556 -- There are no constraints on the body of Remote_Call_Interface or
557 -- Remote_Types packages.
559 return (Unit_Entity /= Standard_Standard)
560 and then (Is_Preelaborated (Unit_Entity)
561 or else Is_Pure (Unit_Entity)
562 or else Is_Shared_Passive (Unit_Entity)
564 ((Is_Remote_Types (Unit_Entity)
565 or else Is_Remote_Call_Interface (Unit_Entity))
566 and then Ekind (Unit_Entity) = E_Package
567 and then Unit_Kind /= N_Package_Body
568 and then not In_Package_Body (Unit_Entity)
569 and then not In_Instance));
570 end In_Preelaborated_Unit;
576 function In_Pure_Unit return Boolean is
578 return Is_Pure (Current_Scope);
581 ------------------------
582 -- In_RCI_Declaration --
583 ------------------------
585 function In_RCI_Declaration return Boolean is
587 return Is_Remote_Call_Interface (Current_Scope)
588 and then In_Package_Declaration;
589 end In_RCI_Declaration;
591 -----------------------
592 -- In_RT_Declaration --
593 -----------------------
595 function In_RT_Declaration return Boolean is
597 return Is_Remote_Types (Current_Scope) and then In_Package_Declaration;
598 end In_RT_Declaration;
600 ----------------------------
601 -- In_Shared_Passive_Unit --
602 ----------------------------
604 function In_Shared_Passive_Unit return Boolean is
605 Unit_Entity : constant Entity_Id := Current_Scope;
608 return Is_Shared_Passive (Unit_Entity);
609 end In_Shared_Passive_Unit;
611 ---------------------------------------
612 -- In_Subprogram_Task_Protected_Unit --
613 ---------------------------------------
615 function In_Subprogram_Task_Protected_Unit return Boolean is
619 -- The following is to verify that a declaration is inside
620 -- subprogram, generic subprogram, task unit, protected unit.
621 -- Used to validate if a lib. unit is Pure. RM 10.2.1(16).
623 -- Use scope chain to check successively outer scopes
627 if Is_Subprogram_Or_Generic_Subprogram (E)
629 Is_Concurrent_Type (E)
633 elsif E = Standard_Standard then
639 end In_Subprogram_Task_Protected_Unit;
641 -------------------------------
642 -- Is_Non_Remote_Access_Type --
643 -------------------------------
645 function Is_Non_Remote_Access_Type (E : Entity_Id) return Boolean is
646 U_E : constant Entity_Id := Underlying_Type (Base_Type (E));
647 -- Use full view of base type to handle subtypes properly.
652 -- This case arises for the case of a generic formal type, in which
653 -- case E.2.2(8) rules will be enforced at instantiation time.
658 return Is_Access_Type (U_E)
659 and then not Is_Remote_Access_To_Class_Wide_Type (U_E)
660 and then not Is_Remote_Access_To_Subprogram_Type (U_E);
661 end Is_Non_Remote_Access_Type;
663 ---------------------------
664 -- No_External_Streaming --
665 ---------------------------
667 function No_External_Streaming (E : Entity_Id) return Boolean is
668 U_E : constant Entity_Id := Underlying_Type (E);
674 elsif Has_Read_Write_Attributes (E) then
676 -- Note: availability of stream attributes is tested on E, not U_E.
677 -- There may be stream attributes defined on U_E that are not visible
678 -- at the place where support of external streaming is tested.
682 elsif Has_Non_Remote_Access (U_E) then
686 return Is_Limited_Type (E);
687 end No_External_Streaming;
689 -------------------------------------
690 -- Set_Categorization_From_Pragmas --
691 -------------------------------------
693 procedure Set_Categorization_From_Pragmas (N : Node_Id) is
694 P : constant Node_Id := Parent (N);
695 S : constant Entity_Id := Current_Scope;
697 procedure Set_Parents (Visibility : Boolean);
698 -- If this is a child instance, the parents are not immediately
699 -- visible during analysis. Make them momentarily visible so that
700 -- the argument of the pragma can be resolved properly, and reset
707 procedure Set_Parents (Visibility : Boolean) is
711 while Present (Par) and then Par /= Standard_Standard loop
712 Set_Is_Immediately_Visible (Par, Visibility);
717 -- Start of processing for Set_Categorization_From_Pragmas
720 -- Deal with categorization pragmas in Pragmas of Compilation_Unit.
721 -- The purpose is to set categorization flags before analyzing the
722 -- unit itself, so as to diagnose violations of categorization as
723 -- we process each declaration, even though the pragma appears after
724 -- the unit. This processing is only needsd if compilation unit
725 -- pragmas are present.
726 -- Note: this code may be incorrect in the unlikely case a child
727 -- genericc unit is instantiated as a child of its (non-generic)
728 -- parent, so that generic and insstance are siblings,
730 if Nkind (P) /= N_Compilation_Unit
731 or else No (First (Pragmas_After (Aux_Decls_Node (P))))
740 if Is_Child_Unit (S) and then Is_Generic_Instance (S) then
744 PN := First (Pragmas_After (Aux_Decls_Node (P)));
745 while Present (PN) loop
747 -- Skip implicit types that may have been introduced by
748 -- previous analysis.
750 if Nkind (PN) = N_Pragma then
751 case Get_Pragma_Id (PN) is
752 when Pragma_All_Calls_Remote
753 | Pragma_Preelaborate
755 | Pragma_Remote_Call_Interface
756 | Pragma_Remote_Types
757 | Pragma_Shared_Passive
769 if Is_Child_Unit (S) and then Is_Generic_Instance (S) then
773 end Set_Categorization_From_Pragmas;
775 -----------------------------------
776 -- Set_Categorization_From_Scope --
777 -----------------------------------
779 procedure Set_Categorization_From_Scope (E : Entity_Id; Scop : Entity_Id) is
780 Declaration : Node_Id := Empty;
781 Specification : Node_Id := Empty;
784 -- Do not modify the purity of an internally generated entity if it has
785 -- been explicitly marked as pure for optimization purposes.
787 if not Has_Pragma_Pure_Function (E) then
789 (E, Is_Pure (Scop) and then Is_Library_Level_Entity (E));
792 if not Is_Remote_Call_Interface (E) then
793 if Ekind (E) in Subprogram_Kind then
794 Declaration := Unit_Declaration_Node (E);
796 if Nkind_In (Declaration, N_Subprogram_Body,
797 N_Subprogram_Renaming_Declaration)
799 Specification := Corresponding_Spec (Declaration);
803 -- A subprogram body or renaming-as-body is a remote call interface
804 -- if it serves as the completion of a subprogram declaration that
805 -- is a remote call interface.
807 if Nkind (Specification) in N_Entity then
808 Set_Is_Remote_Call_Interface
809 (E, Is_Remote_Call_Interface (Specification));
811 -- A subprogram declaration is a remote call interface when it is
812 -- declared within the visible part of, or declared by, a library
813 -- unit declaration that is a remote call interface.
816 Set_Is_Remote_Call_Interface
817 (E, Is_Remote_Call_Interface (Scop)
818 and then not (In_Private_Part (Scop)
819 or else In_Package_Body (Scop)));
824 (E, Is_Remote_Types (Scop)
825 and then not (In_Private_Part (Scop)
826 or else In_Package_Body (Scop)));
827 end Set_Categorization_From_Scope;
829 ------------------------------
830 -- Static_Discriminant_Expr --
831 ------------------------------
833 -- We need to accommodate a Why_Not_Static call somehow here ???
835 function Static_Discriminant_Expr (L : List_Id) return Boolean is
836 Discriminant_Spec : Node_Id;
839 Discriminant_Spec := First (L);
840 while Present (Discriminant_Spec) loop
841 if Present (Expression (Discriminant_Spec))
843 not Is_OK_Static_Expression (Expression (Discriminant_Spec))
848 Next (Discriminant_Spec);
852 end Static_Discriminant_Expr;
854 --------------------------------------
855 -- Validate_Access_Type_Declaration --
856 --------------------------------------
858 procedure Validate_Access_Type_Declaration (T : Entity_Id; N : Node_Id) is
859 Def : constant Node_Id := Type_Definition (N);
864 -- Access to subprogram case
866 when N_Access_To_Subprogram_Definition =>
868 -- A pure library_item must not contain the declaration of a
869 -- named access type, except within a subprogram, generic
870 -- subprogram, task unit, or protected unit (RM 10.2.1(16)).
872 -- This test is skipped in Ada 2005 (see AI-366)
874 if Ada_Version < Ada_2005
875 and then Comes_From_Source (T)
876 and then In_Pure_Unit
877 and then not In_Subprogram_Task_Protected_Unit
879 Error_Msg_N ("named access type not allowed in pure unit", T);
882 -- Access to object case
884 when N_Access_To_Object_Definition =>
885 if Comes_From_Source (T)
886 and then In_Pure_Unit
887 and then not In_Subprogram_Task_Protected_Unit
889 -- We can't give the message yet, since the type is not frozen
890 -- and in Ada 2005 mode, access types are allowed in pure units
891 -- if the type has no storage pool (see AI-366). So we set a
892 -- flag which will be checked at freeze time.
894 Set_Is_Pure_Unit_Access_Type (T);
897 -- Check for RCI or RT unit type declaration: declaration of an
898 -- access-to-object type is illegal unless it is a general access
899 -- type that designates a class-wide limited private type.
900 -- Note that constraints on the primitive subprograms of the
901 -- designated tagged type are not enforced here but in
902 -- Validate_RACW_Primitives, which is done separately because the
903 -- designated type might not be frozen (and therefore its
904 -- primitive operations might not be completely known) at the
905 -- point of the RACW declaration.
907 Validate_Remote_Access_Object_Type_Declaration (T);
909 -- Check for shared passive unit type declaration. It should
910 -- not contain the declaration of access to class wide type,
911 -- access to task type and access to protected type with entry.
913 Validate_SP_Access_Object_Type_Decl (T);
919 -- Set categorization flag from package on entity as well, to allow
920 -- easy checks later on for required validations of RCI or RT units.
921 -- This is only done for entities that are in the original source.
923 if Comes_From_Source (T)
924 and then not (In_Package_Body (Scope (T))
925 or else In_Private_Part (Scope (T)))
927 Set_Is_Remote_Call_Interface
928 (T, Is_Remote_Call_Interface (Scope (T)));
930 (T, Is_Remote_Types (Scope (T)));
932 end Validate_Access_Type_Declaration;
934 ----------------------------
935 -- Validate_Ancestor_Part --
936 ----------------------------
938 procedure Validate_Ancestor_Part (N : Node_Id) is
939 A : constant Node_Id := Ancestor_Part (N);
940 T : constant Entity_Id := Entity (A);
943 if In_Preelaborated_Unit
944 and then not In_Subprogram_Or_Concurrent_Unit
945 and then (not Inside_A_Generic
946 or else Present (Enclosing_Generic_Body (N)))
948 -- If the type is private, it must have the Ada 2005 pragma
949 -- Has_Preelaborable_Initialization.
951 -- The check is omitted within predefined units. This is probably
952 -- obsolete code to fix the Ada 95 weakness in this area ???
954 if Is_Private_Type (T)
955 and then not Has_Pragma_Preelab_Init (T)
956 and then not In_Internal_Unit (N)
959 ("private ancestor type not allowed in preelaborated unit", A);
961 elsif Is_Record_Type (T) then
962 if Nkind (Parent (T)) = N_Full_Type_Declaration then
963 Check_Non_Static_Default_Expr
964 (Type_Definition (Parent (T)), A);
968 end Validate_Ancestor_Part;
970 ----------------------------------------
971 -- Validate_Categorization_Dependency --
972 ----------------------------------------
974 procedure Validate_Categorization_Dependency
978 K : constant Node_Kind := Nkind (N);
979 P : Node_Id := Parent (N);
981 Is_Subunit : constant Boolean := Nkind (P) = N_Subunit;
984 -- Only validate library units and subunits. For subunits, checks
985 -- concerning withed units apply to the parent compilation unit.
992 and then not Is_Compilation_Unit (U)
993 and then not Is_Child_Unit (U)
999 if Nkind (P) /= N_Compilation_Unit then
1003 -- Body of RCI unit does not need validation
1005 if Is_Remote_Call_Interface (E)
1006 and then Nkind_In (N, N_Package_Body, N_Subprogram_Body)
1011 -- Ada 2005 (AI-50217): Process explicit non-limited with_clauses
1015 Entity_Of_Withed : Entity_Id;
1018 Item := First (Context_Items (P));
1019 while Present (Item) loop
1020 if Nkind (Item) = N_With_Clause
1022 not (Implicit_With (Item)
1023 or else Limited_Present (Item)
1025 -- Skip if error already posted on the WITH clause (in
1026 -- which case the Name attribute may be invalid). In
1027 -- particular, this fixes the problem of hanging in the
1028 -- presence of a WITH clause on a child that is an
1029 -- illegal generic instantiation.
1031 or else Error_Posted (Item))
1035 -- Skip processing malformed trees
1037 and then Nkind (Name (Item)) not in N_Has_Entity)
1039 Entity_Of_Withed := Entity (Name (Item));
1040 Check_Categorization_Dependencies
1041 (U, Entity_Of_Withed, Item, Is_Subunit);
1048 -- Child depends on parent; therefore parent should also be categorized
1049 -- and satisfy the dependency hierarchy.
1051 -- Check if N is a child spec
1053 if (K in N_Generic_Declaration or else
1054 K in N_Generic_Instantiation or else
1055 K in N_Generic_Renaming_Declaration or else
1056 K = N_Package_Declaration or else
1057 K = N_Package_Renaming_Declaration or else
1058 K = N_Subprogram_Declaration or else
1059 K = N_Subprogram_Renaming_Declaration)
1060 and then Present (Parent_Spec (N))
1062 Check_Categorization_Dependencies (E, Scope (E), N, False);
1064 -- Verify that public child of an RCI library unit must also be an
1065 -- RCI library unit (RM E.2.3(15)).
1067 if Is_Remote_Call_Interface (Scope (E))
1068 and then not Private_Present (P)
1069 and then not Is_Remote_Call_Interface (E)
1071 Error_Msg_N ("public child of rci unit must also be rci unit", N);
1074 end Validate_Categorization_Dependency;
1076 --------------------------------
1077 -- Validate_Controlled_Object --
1078 --------------------------------
1080 procedure Validate_Controlled_Object (E : Entity_Id) is
1082 -- Don't need this check in Ada 2005 mode, where this is all taken
1083 -- care of by the mechanism for Preelaborable Initialization.
1085 if Ada_Version >= Ada_2005 then
1089 -- For now, never apply this check for internal GNAT units, since we
1090 -- have a number of cases in the library where we are stuck with objects
1091 -- of this type, and the RM requires Preelaborate.
1093 -- For similar reasons, we only do this check for source entities, since
1094 -- we generate entities of this type in some situations.
1096 -- Note that the 10.2.1(9) restrictions are not relevant to us anyway.
1097 -- We have to enforce them for RM compatibility, but we have no trouble
1098 -- accepting these objects and doing the right thing. Note that there is
1099 -- no requirement that Preelaborate not actually generate any code.
1101 if In_Preelaborated_Unit
1102 and then not Debug_Flag_PP
1103 and then Comes_From_Source (E)
1104 and then not In_Internal_Unit (E)
1105 and then (not Inside_A_Generic
1106 or else Present (Enclosing_Generic_Body (E)))
1107 and then not Is_Protected_Type (Etype (E))
1110 ("library level controlled object not allowed in " &
1111 "preelaborated unit", E);
1113 end Validate_Controlled_Object;
1115 --------------------------------------
1116 -- Validate_Null_Statement_Sequence --
1117 --------------------------------------
1119 procedure Validate_Null_Statement_Sequence (N : Node_Id) is
1123 if In_Preelaborated_Unit then
1124 Item := First (Statements (Handled_Statement_Sequence (N)));
1125 while Present (Item) loop
1126 if Nkind (Item) /= N_Label
1127 and then Nkind (Item) /= N_Null_Statement
1129 -- In GNAT mode, this is a warning, allowing the run-time
1130 -- to judiciously bypass this error condition.
1132 Error_Msg_Warn := GNAT_Mode;
1134 ("<<statements not allowed in preelaborated unit", Item);
1142 end Validate_Null_Statement_Sequence;
1144 ---------------------------------
1145 -- Validate_Object_Declaration --
1146 ---------------------------------
1148 procedure Validate_Object_Declaration (N : Node_Id) is
1149 Id : constant Entity_Id := Defining_Identifier (N);
1150 E : constant Node_Id := Expression (N);
1151 Odf : constant Node_Id := Object_Definition (N);
1152 T : constant Entity_Id := Etype (Id);
1155 -- Verify that any access to subprogram object does not have in its
1156 -- subprogram profile access type parameters or limited parameters
1157 -- without Read and Write attributes (E.2.3(13)).
1159 Validate_RCI_Subprogram_Declaration (N);
1161 -- Check that if we are in preelaborated elaboration code, then we
1162 -- do not have an instance of a default initialized private, task or
1163 -- protected object declaration which would violate (RM 10.2.1(9)).
1164 -- Note that constants are never default initialized (and the test
1165 -- below also filters out deferred constants). A variable is default
1166 -- initialized if it does *not* have an initialization expression.
1168 -- Filter out cases that are not declaration of a variable from source
1170 if Nkind (N) /= N_Object_Declaration
1171 or else Constant_Present (N)
1172 or else not Comes_From_Source (Id)
1177 -- Exclude generic specs from the checks (this will get rechecked
1178 -- on instantiations).
1180 if Inside_A_Generic and then No (Enclosing_Generic_Body (Id)) then
1184 -- Required checks for declaration that is in a preelaborated package
1185 -- and is not within some subprogram.
1187 if In_Preelaborated_Unit
1188 and then not In_Subprogram_Or_Concurrent_Unit
1190 -- Check for default initialized variable case. Note that in
1191 -- accordance with (RM B.1(24)) imported objects are not subject to
1192 -- default initialization.
1193 -- If the initialization does not come from source and is an
1194 -- aggregate, it is a static initialization that replaces an
1195 -- implicit call, and must be treated as such.
1198 and then (Comes_From_Source (E) or else Nkind (E) /= N_Aggregate)
1202 elsif Is_Imported (Id) then
1207 Ent : Entity_Id := T;
1210 -- An array whose component type is a record with nonstatic
1211 -- default expressions is a violation, so we get the array's
1214 if Is_Array_Type (Ent) then
1216 Comp_Type : Entity_Id;
1219 Comp_Type := Component_Type (Ent);
1220 while Is_Array_Type (Comp_Type) loop
1221 Comp_Type := Component_Type (Comp_Type);
1228 -- Object decl. that is of record type and has no default expr.
1229 -- should check if there is any non-static default expression
1230 -- in component decl. of the record type decl.
1232 if Is_Record_Type (Ent) then
1233 if Nkind (Parent (Ent)) = N_Full_Type_Declaration then
1234 Check_Non_Static_Default_Expr
1235 (Type_Definition (Parent (Ent)), N);
1237 elsif Nkind (Odf) = N_Subtype_Indication
1238 and then not Is_Array_Type (T)
1239 and then not Is_Private_Type (T)
1241 Check_Non_Static_Default_Expr (Type_Definition
1242 (Parent (Entity (Subtype_Mark (Odf)))), N);
1246 -- Check for invalid use of private object. Note that Ada 2005
1247 -- AI-161 modifies the rules for Ada 2005, including the use of
1248 -- the new pragma Preelaborable_Initialization.
1250 if Is_Private_Type (Ent)
1251 or else Depends_On_Private (Ent)
1253 -- Case where type has preelaborable initialization which
1254 -- means that a pragma Preelaborable_Initialization was
1255 -- given for the private type.
1257 if Relaxed_RM_Semantics then
1259 -- In relaxed mode, do not issue these messages, this
1260 -- is basically similar to the GNAT_Mode test below.
1264 elsif Has_Preelaborable_Initialization (Ent) then
1266 -- But for the predefined units, we will ignore this
1267 -- status unless we are in Ada 2005 mode since we want
1268 -- Ada 95 compatible behavior, in which the entities
1269 -- marked with this pragma in the predefined library are
1270 -- not treated specially.
1272 if Ada_Version < Ada_2005 then
1274 ("private object not allowed in preelaborated unit",
1276 Error_Msg_N ("\(would be legal in Ada 2005 mode)", N);
1279 -- Type does not have preelaborable initialization
1282 -- We allow this when compiling in GNAT mode to make life
1283 -- easier for some cases where it would otherwise be hard
1284 -- to be exactly valid Ada.
1286 if not GNAT_Mode then
1288 ("private object not allowed in preelaborated unit",
1291 -- Add a message if it would help to provide a pragma
1292 -- Preelaborable_Initialization on the type of the
1293 -- object (which would make it legal in Ada 2005).
1295 -- If the type has no full view (generic type, or
1296 -- previous error), the warning does not apply.
1298 if Is_Private_Type (Ent)
1299 and then Present (Full_View (Ent))
1301 Has_Preelaborable_Initialization (Full_View (Ent))
1303 Error_Msg_Sloc := Sloc (Ent);
1305 if Ada_Version >= Ada_2005 then
1307 ("\would be legal if pragma Preelaborable_" &
1308 "Initialization given for & #", N, Ent);
1311 ("\would be legal in Ada 2005 if pragma " &
1312 "Preelaborable_Initialization given for & #",
1319 -- Access to Task or Protected type
1321 elsif Is_Entity_Name (Odf)
1322 and then Present (Etype (Odf))
1323 and then Is_Access_Type (Etype (Odf))
1325 Ent := Designated_Type (Etype (Odf));
1327 elsif Is_Entity_Name (Odf) then
1328 Ent := Entity (Odf);
1330 elsif Nkind (Odf) = N_Subtype_Indication then
1331 Ent := Etype (Subtype_Mark (Odf));
1333 elsif Nkind (Odf) = N_Constrained_Array_Definition then
1334 Ent := Component_Type (T);
1337 if Is_Task_Type (Ent)
1338 or else (Is_Protected_Type (Ent) and then Has_Entries (Ent))
1341 ("concurrent object not allowed in preelaborated unit",
1348 -- Non-static discriminants not allowed in preelaborated unit.
1349 -- Objects of a controlled type with a user-defined Initialize
1350 -- are forbidden as well.
1352 if Is_Record_Type (Etype (Id)) then
1354 ET : constant Entity_Id := Etype (Id);
1355 EE : constant Entity_Id := Etype (Etype (Id));
1359 if Has_Discriminants (ET) and then Present (EE) then
1362 if Nkind (PEE) = N_Full_Type_Declaration
1363 and then not Static_Discriminant_Expr
1364 (Discriminant_Specifications (PEE))
1367 ("non-static discriminant in preelaborated unit",
1372 -- For controlled type or type with controlled component, check
1373 -- preelaboration flag, as there may be a non-null Initialize
1374 -- primitive. For language versions earlier than Ada 2005,
1375 -- there is no notion of preelaborable initialization, and
1376 -- Validate_Controlled_Object is used to enforce rules for
1377 -- controlled objects.
1379 if (Is_Controlled (ET) or else Has_Controlled_Component (ET))
1380 and then Ada_Version >= Ada_2005
1381 and then not Has_Preelaborable_Initialization (ET)
1384 ("controlled type& does not have"
1385 & " preelaborable initialization", N, ET);
1392 -- A pure library_item must not contain the declaration of any variable
1393 -- except within a subprogram, generic subprogram, task unit, or
1394 -- protected unit (RM 10.2.1(16)).
1396 if In_Pure_Unit and then not In_Subprogram_Task_Protected_Unit then
1397 Error_Msg_N ("declaration of variable not allowed in pure unit", N);
1399 elsif not In_Private_Part (Id) then
1401 -- The visible part of an RCI library unit must not contain the
1402 -- declaration of a variable (RM E.1.3(9)).
1404 if In_RCI_Declaration then
1405 Error_Msg_N ("visible variable not allowed in 'R'C'I unit", N);
1407 -- The visible part of a Shared Passive library unit must not contain
1408 -- the declaration of a variable (RM E.2.2(7)).
1410 elsif In_RT_Declaration then
1412 ("visible variable not allowed in remote types unit", N);
1415 end Validate_Object_Declaration;
1417 -----------------------------
1418 -- Validate_RACW_Primitive --
1419 -----------------------------
1421 procedure Validate_RACW_Primitive
1425 procedure Illegal_Remote_Subp (Msg : String; N : Node_Id);
1426 -- Diagnose illegality on N. If RACW is present, report the error on it
1427 -- rather than on N.
1429 -------------------------
1430 -- Illegal_Remote_Subp --
1431 -------------------------
1433 procedure Illegal_Remote_Subp (Msg : String; N : Node_Id) is
1435 if Present (RACW) then
1436 if not Error_Posted (RACW) then
1438 ("illegal remote access to class-wide type&", RACW);
1441 Error_Msg_Sloc := Sloc (N);
1442 Error_Msg_NE ("\\" & Msg & " in primitive& #", RACW, Subp);
1445 Error_Msg_NE (Msg & " in remote subprogram&", N, Subp);
1447 end Illegal_Remote_Subp;
1451 Param_Spec : Node_Id;
1452 Param_Type : Entity_Id;
1454 -- Start of processing for Validate_RACW_Primitive
1457 -- Check return type
1459 if Ekind (Subp) = E_Function then
1460 Rtyp := Etype (Subp);
1462 -- AI05-0101 (Binding Interpretation): The result type of a remote
1463 -- function must either support external streaming or be a
1464 -- controlling access result type.
1466 if Has_Controlling_Result (Subp) then
1469 elsif Ekind (Rtyp) = E_Anonymous_Access_Type then
1470 Illegal_Remote_Subp ("anonymous access result", Rtyp);
1472 elsif Is_Limited_Type (Rtyp) then
1473 if No (TSS (Rtyp, TSS_Stream_Read))
1475 No (TSS (Rtyp, TSS_Stream_Write))
1478 ("limited return type must have Read and Write attributes",
1480 Explain_Limited_Type (Rtyp, Parent (Subp));
1483 -- Check that the return type supports external streaming
1485 elsif No_External_Streaming (Rtyp)
1486 and then not Error_Posted (Rtyp)
1488 Illegal_Remote_Subp ("return type containing non-remote access "
1489 & "must have Read and Write attributes",
1494 Param := First_Formal (Subp);
1495 while Present (Param) loop
1497 -- Now find out if this parameter is a controlling parameter
1499 Param_Spec := Parent (Param);
1500 Param_Type := Etype (Param);
1502 if Is_Controlling_Formal (Param) then
1504 -- It is a controlling parameter, so specific checks below do not
1509 elsif Ekind_In (Param_Type, E_Anonymous_Access_Type,
1510 E_Anonymous_Access_Subprogram_Type)
1512 -- From RM E.2.2(14), no anonymous access parameter other than
1513 -- controlling ones may be used (because an anonymous access
1514 -- type never supports external streaming).
1517 ("non-controlling access parameter", Param_Spec);
1519 elsif No_External_Streaming (Param_Type)
1520 and then not Error_Posted (Param_Type)
1522 Illegal_Remote_Subp ("formal parameter in remote subprogram must "
1523 & "support external streaming", Param_Spec);
1526 -- Check next parameter in this subprogram
1528 Next_Formal (Param);
1530 end Validate_RACW_Primitive;
1532 ------------------------------
1533 -- Validate_RACW_Primitives --
1534 ------------------------------
1536 procedure Validate_RACW_Primitives (T : Entity_Id) is
1537 Desig_Type : Entity_Id;
1538 Primitive_Subprograms : Elist_Id;
1539 Subprogram_Elmt : Elmt_Id;
1540 Subprogram : Entity_Id;
1543 Desig_Type := Etype (Designated_Type (T));
1545 -- No action needed for concurrent types
1547 if Is_Concurrent_Type (Desig_Type) then
1551 Primitive_Subprograms := Primitive_Operations (Desig_Type);
1553 Subprogram_Elmt := First_Elmt (Primitive_Subprograms);
1554 while Subprogram_Elmt /= No_Elmt loop
1555 Subprogram := Node (Subprogram_Elmt);
1557 if Is_Predefined_Dispatching_Operation (Subprogram)
1558 or else Is_Hidden (Subprogram)
1560 goto Next_Subprogram;
1563 Validate_RACW_Primitive (Subp => Subprogram, RACW => T);
1566 Next_Elmt (Subprogram_Elmt);
1568 end Validate_RACW_Primitives;
1570 -------------------------------
1571 -- Validate_RCI_Declarations --
1572 -------------------------------
1574 procedure Validate_RCI_Declarations (P : Entity_Id) is
1578 E := First_Entity (P);
1579 while Present (E) loop
1580 if Comes_From_Source (E) then
1581 if Is_Limited_Type (E) then
1583 ("limited type not allowed in rci unit", Parent (E));
1584 Explain_Limited_Type (E, Parent (E));
1586 elsif Ekind_In (E, E_Generic_Function,
1588 E_Generic_Procedure)
1590 Error_Msg_N ("generic declaration not allowed in rci unit",
1593 elsif (Ekind (E) = E_Function or else Ekind (E) = E_Procedure)
1594 and then Has_Pragma_Inline (E)
1597 ("inlined subprogram not allowed in rci unit", Parent (E));
1599 -- Inner packages that are renamings need not be checked. Generic
1600 -- RCI packages are subject to the checks, but entities that come
1601 -- from formal packages are not part of the visible declarations
1602 -- of the package and are not checked.
1604 elsif Ekind (E) = E_Package then
1605 if Present (Renamed_Entity (E)) then
1608 elsif Ekind (P) /= E_Generic_Package
1609 or else List_Containing (Unit_Declaration_Node (E)) /=
1610 Generic_Formal_Declarations
1611 (Unit_Declaration_Node (P))
1613 Validate_RCI_Declarations (E);
1620 end Validate_RCI_Declarations;
1622 -----------------------------------------
1623 -- Validate_RCI_Subprogram_Declaration --
1624 -----------------------------------------
1626 procedure Validate_RCI_Subprogram_Declaration (N : Node_Id) is
1627 K : constant Node_Kind := Nkind (N);
1629 Id : constant Entity_Id := Defining_Entity (N);
1630 Param_Spec : Node_Id;
1631 Param_Type : Entity_Id;
1632 Error_Node : Node_Id := N;
1635 -- This procedure enforces rules on subprogram and access to subprogram
1636 -- declarations in RCI units. These rules do not apply to expander
1637 -- generated routines, which are not remote subprograms. It is called:
1639 -- 1. from Analyze_Subprogram_Declaration.
1640 -- 2. from Validate_Object_Declaration (access to subprogram).
1642 if not (Comes_From_Source (N)
1643 and then In_RCI_Declaration
1644 and then not In_Private_Part (Scope (Id)))
1649 if K = N_Subprogram_Declaration then
1650 Profile := Parameter_Specifications (Specification (N));
1653 pragma Assert (K = N_Object_Declaration);
1655 -- The above assertion is dubious, the visible declarations of an
1656 -- RCI unit never contain an object declaration, this should be an
1657 -- ACCESS-to-object declaration???
1659 if Nkind (Id) = N_Defining_Identifier
1660 and then Nkind (Parent (Etype (Id))) = N_Full_Type_Declaration
1661 and then Ekind (Etype (Id)) = E_Access_Subprogram_Type
1664 Parameter_Specifications (Type_Definition (Parent (Etype (Id))));
1670 -- Iterate through the parameter specification list, checking that
1671 -- no access parameter and no limited type parameter in the list.
1674 if Present (Profile) then
1675 Param_Spec := First (Profile);
1676 while Present (Param_Spec) loop
1677 Param_Type := Etype (Defining_Identifier (Param_Spec));
1679 if Ekind (Param_Type) = E_Anonymous_Access_Type then
1680 if K = N_Subprogram_Declaration then
1681 Error_Node := Param_Spec;
1684 -- Report error only if declaration is in source program
1686 if Comes_From_Source (Id) then
1688 ("subprogram in 'R'C'I unit cannot have access parameter",
1692 -- For a limited private type parameter, we check only the private
1693 -- declaration and ignore full type declaration, unless this is
1694 -- the only declaration for the type, e.g., as a limited record.
1696 elsif No_External_Streaming (Param_Type) then
1697 if K = N_Subprogram_Declaration then
1698 Error_Node := Param_Spec;
1702 ("formal of remote subprogram& "
1703 & "must support external streaming",
1705 if Is_Limited_Type (Param_Type) then
1706 Explain_Limited_Type (Param_Type, Error_Node);
1714 if Ekind (Id) = E_Function
1715 and then Ekind (Etype (Id)) = E_Anonymous_Access_Type
1716 and then Comes_From_Source (Id)
1719 ("function in 'R'C'I unit cannot have access result",
1722 end Validate_RCI_Subprogram_Declaration;
1724 ----------------------------------------------------
1725 -- Validate_Remote_Access_Object_Type_Declaration --
1726 ----------------------------------------------------
1728 procedure Validate_Remote_Access_Object_Type_Declaration (T : Entity_Id) is
1729 Direct_Designated_Type : Entity_Id;
1730 Desig_Type : Entity_Id;
1733 -- We are called from Analyze_Full_Type_Declaration, and the Nkind of
1734 -- the given node is N_Access_To_Object_Definition.
1736 if not Comes_From_Source (T)
1737 or else (not In_RCI_Declaration and then not In_RT_Declaration)
1742 -- An access definition in the private part of a package is not a
1743 -- remote access type. Restrictions related to external streaming
1744 -- support for non-remote access types are enforced elsewhere. Note
1745 -- that In_Private_Part is never set on type entities: check flag
1746 -- on enclosing scope.
1748 if In_Private_Part (Scope (T)) then
1752 -- Check RCI or RT unit type declaration. It may not contain the
1753 -- declaration of an access-to-object type unless it is a general access
1754 -- type that designates a class-wide limited private type or subtype.
1755 -- There are also constraints on the primitive subprograms of the
1756 -- class-wide type (RM E.2.2(14), see Validate_RACW_Primitives).
1758 if Ekind (T) /= E_General_Access_Type
1759 or else not Is_Class_Wide_Type (Designated_Type (T))
1761 if In_RCI_Declaration then
1763 ("error in access type in Remote_Call_Interface unit", T);
1766 ("error in access type in Remote_Types unit", T);
1769 Error_Msg_N ("\must be general access to class-wide type", T);
1773 Direct_Designated_Type := Designated_Type (T);
1774 Desig_Type := Etype (Direct_Designated_Type);
1776 -- Why is this check not in Validate_Remote_Access_To_Class_Wide_Type???
1778 if not Is_Valid_Remote_Object_Type (Desig_Type) then
1780 ("error in designated type of remote access to class-wide type", T);
1782 ("\must be tagged limited private or private extension", T);
1785 end Validate_Remote_Access_Object_Type_Declaration;
1787 -----------------------------------------------
1788 -- Validate_Remote_Access_To_Class_Wide_Type --
1789 -----------------------------------------------
1791 procedure Validate_Remote_Access_To_Class_Wide_Type (N : Node_Id) is
1792 K : constant Node_Kind := Nkind (N);
1793 PK : constant Node_Kind := Nkind (Parent (N));
1797 -- This subprogram enforces the checks in (RM E.2.2(8)) for certain uses
1798 -- of class-wide limited private types.
1800 -- Storage_Pool and Storage_Size are not defined for such types
1802 -- The expected type of allocator must not be such a type.
1804 -- The actual parameter of generic instantiation must not be such a
1805 -- type if the formal parameter is of an access type.
1807 -- On entry, there are several cases:
1809 -- 1. called from sem_attr Analyze_Attribute where attribute name is
1810 -- either Storage_Pool or Storage_Size.
1812 -- 2. called from exp_ch4 Expand_N_Allocator
1814 -- 3. called from sem_ch4 Analyze_Explicit_Dereference
1816 -- 4. called from sem_res Resolve_Actuals
1818 if K = N_Attribute_Reference then
1819 E := Etype (Prefix (N));
1821 if Is_Remote_Access_To_Class_Wide_Type (E) then
1822 Error_Msg_N ("incorrect attribute of remote operand", N);
1826 elsif K = N_Allocator then
1829 if Is_Remote_Access_To_Class_Wide_Type (E) then
1830 Error_Msg_N ("incorrect expected remote type of allocator", N);
1834 -- This subprogram also enforces the checks in E.2.2(13). A value of
1835 -- such type must not be dereferenced unless as controlling operand of
1836 -- a dispatching call. Explicit dereferences not coming from source are
1837 -- exempted from this checking because the expander produces them in
1838 -- some cases (such as for tag checks on dispatching calls with multiple
1839 -- controlling operands). However we do check in the case of an implicit
1840 -- dereference that is expanded to an explicit dereference (hence the
1841 -- test of whether Original_Node (N) comes from source).
1843 elsif K = N_Explicit_Dereference
1844 and then Comes_From_Source (Original_Node (N))
1846 E := Etype (Prefix (N));
1848 -- If the class-wide type is not a remote one, the restrictions
1851 if not Is_Remote_Access_To_Class_Wide_Type (E) then
1855 -- If we have a true dereference that comes from source and that
1856 -- is a controlling argument for a dispatching call, accept it.
1858 if Is_Actual_Parameter (N) and then Is_Controlling_Actual (N) then
1862 -- If we are just within a procedure or function call and the
1863 -- dereference has not been analyzed, return because this procedure
1864 -- will be called again from sem_res Resolve_Actuals. The same can
1865 -- apply in the case of dereference that is the prefix of a selected
1866 -- component, which can be a call given in prefixed form.
1868 if (Is_Actual_Parameter (N) or else PK = N_Selected_Component)
1869 and then not Analyzed (N)
1874 -- We must allow expanded code to generate a reference to the tag of
1875 -- the designated object (may be either the actual tag, or the stub
1876 -- tag in the case of a remote object).
1878 if PK = N_Selected_Component
1879 and then Is_Tag (Entity (Selector_Name (Parent (N))))
1885 ("invalid dereference of a remote access-to-class-wide value", N);
1887 end Validate_Remote_Access_To_Class_Wide_Type;
1889 ------------------------------------------
1890 -- Validate_Remote_Type_Type_Conversion --
1891 ------------------------------------------
1893 procedure Validate_Remote_Type_Type_Conversion (N : Node_Id) is
1894 S : constant Entity_Id := Etype (N);
1895 E : constant Entity_Id := Etype (Expression (N));
1898 -- This test is required in the case where a conversion appears inside a
1899 -- normal package, it does not necessarily have to be inside an RCI,
1900 -- Remote_Types unit (RM E.2.2(9,12)).
1902 if Is_Remote_Access_To_Subprogram_Type (E)
1903 and then not Is_Remote_Access_To_Subprogram_Type (S)
1906 ("incorrect conversion of remote operand to local type", N);
1909 elsif not Is_Remote_Access_To_Subprogram_Type (E)
1910 and then Is_Remote_Access_To_Subprogram_Type (S)
1913 ("incorrect conversion of local operand to remote type", N);
1916 elsif Is_Remote_Access_To_Class_Wide_Type (E)
1917 and then not Is_Remote_Access_To_Class_Wide_Type (S)
1920 ("incorrect conversion of remote operand to local type", N);
1924 -- If a local access type is converted into a RACW type, then the
1925 -- current unit has a pointer that may now be exported to another
1928 if Is_Remote_Access_To_Class_Wide_Type (S)
1929 and then not Is_Remote_Access_To_Class_Wide_Type (E)
1931 Set_Has_RACW (Current_Sem_Unit);
1933 end Validate_Remote_Type_Type_Conversion;
1935 -------------------------------
1936 -- Validate_RT_RAT_Component --
1937 -------------------------------
1939 procedure Validate_RT_RAT_Component (N : Node_Id) is
1940 Spec : constant Node_Id := Specification (N);
1941 Name_U : constant Entity_Id := Defining_Entity (Spec);
1944 First_Priv_Ent : constant Entity_Id := First_Private_Entity (Name_U);
1946 function Stream_Attributes_Available (Typ : Entity_Id) return Boolean;
1947 -- True if any stream attribute is available for Typ
1949 ---------------------------------
1950 -- Stream_Attributes_Available --
1951 ---------------------------------
1953 function Stream_Attributes_Available (Typ : Entity_Id) return Boolean
1956 return Stream_Attribute_Available (Typ, TSS_Stream_Read)
1958 Stream_Attribute_Available (Typ, TSS_Stream_Write)
1960 Stream_Attribute_Available (Typ, TSS_Stream_Input)
1962 Stream_Attribute_Available (Typ, TSS_Stream_Output);
1963 end Stream_Attributes_Available;
1965 -- Start of processing for Validate_RT_RAT_Component
1968 if not Is_Remote_Types (Name_U) then
1972 Typ := First_Entity (Name_U);
1973 while Present (Typ) and then Typ /= First_Priv_Ent loop
1974 U_Typ := Underlying_Type (Base_Type (Typ));
1980 if Comes_From_Source (Typ) and then Is_Type (Typ)
1981 and then Ekind (Typ) /= E_Incomplete_Type
1983 -- Check that the type can be meaningfully transmitted to another
1984 -- partition (E.2.2(8)).
1986 if (Ada_Version < Ada_2005 and then Has_Non_Remote_Access (U_Typ))
1987 or else (Stream_Attributes_Available (Typ)
1988 and then No_External_Streaming (U_Typ))
1990 if Is_Non_Remote_Access_Type (Typ) then
1991 Error_Msg_N ("error in non-remote access type", U_Typ);
1994 ("error in record type containing a component of a " &
1995 "non-remote access type", U_Typ);
1998 if Ada_Version >= Ada_2005 then
2000 ("\must have visible Read and Write attribute " &
2001 "definition clauses (RM E.2.2(8))", U_Typ);
2004 ("\must have Read and Write attribute " &
2005 "definition clauses (RM E.2.2(8))", U_Typ);
2012 end Validate_RT_RAT_Component;
2014 -----------------------------------------
2015 -- Validate_SP_Access_Object_Type_Decl --
2016 -----------------------------------------
2018 procedure Validate_SP_Access_Object_Type_Decl (T : Entity_Id) is
2019 Direct_Designated_Type : Entity_Id;
2021 function Has_Entry_Declarations (E : Entity_Id) return Boolean;
2022 -- Return true if the protected type designated by T has entry
2025 ----------------------------
2026 -- Has_Entry_Declarations --
2027 ----------------------------
2029 function Has_Entry_Declarations (E : Entity_Id) return Boolean is
2033 if Nkind (Parent (E)) = N_Protected_Type_Declaration then
2034 Ety := First_Entity (E);
2035 while Present (Ety) loop
2036 if Ekind (Ety) = E_Entry then
2045 end Has_Entry_Declarations;
2047 -- Start of processing for Validate_SP_Access_Object_Type_Decl
2050 -- We are called from Sem_Ch3.Analyze_Full_Type_Declaration, and the
2051 -- Nkind of the given entity is N_Access_To_Object_Definition.
2053 if not Comes_From_Source (T)
2054 or else not In_Shared_Passive_Unit
2055 or else In_Subprogram_Task_Protected_Unit
2060 -- Check Shared Passive unit. It should not contain the declaration
2061 -- of an access-to-object type whose designated type is a class-wide
2062 -- type, task type or protected type with entry (RM E.2.1(7)).
2064 Direct_Designated_Type := Designated_Type (T);
2066 if Ekind (Direct_Designated_Type) = E_Class_Wide_Type then
2068 ("invalid access-to-class-wide type in shared passive unit", T);
2071 elsif Ekind (Direct_Designated_Type) in Task_Kind then
2073 ("invalid access-to-task type in shared passive unit", T);
2076 elsif Ekind (Direct_Designated_Type) in Protected_Kind
2077 and then Has_Entry_Declarations (Direct_Designated_Type)
2080 ("invalid access-to-protected type in shared passive unit", T);
2083 end Validate_SP_Access_Object_Type_Decl;
2085 ---------------------------------
2086 -- Validate_Static_Object_Name --
2087 ---------------------------------
2089 procedure Validate_Static_Object_Name (N : Node_Id) is
2093 function Is_Primary (N : Node_Id) return Boolean;
2094 -- Determine whether node is syntactically a primary in an expression
2095 -- This function should probably be somewhere else ???
2097 -- Also it does not do what it says, e.g if N is a binary operator
2098 -- whose parent is a binary operator, Is_Primary returns True ???
2104 function Is_Primary (N : Node_Id) return Boolean is
2105 K : constant Node_Kind := Nkind (Parent (N));
2110 | N_Component_Association
2111 | N_Index_Or_Discriminant_Constraint
2117 when N_Attribute_Reference =>
2119 Attr : constant Name_Id := Attribute_Name (Parent (N));
2122 return Attr /= Name_Address
2123 and then Attr /= Name_Access
2124 and then Attr /= Name_Unchecked_Access
2125 and then Attr /= Name_Unrestricted_Access;
2128 when N_Indexed_Component =>
2129 return N /= Prefix (Parent (N)) or else Is_Primary (Parent (N));
2131 when N_Qualified_Expression
2134 return Is_Primary (Parent (N));
2136 when N_Assignment_Statement
2137 | N_Object_Declaration
2139 return N = Expression (Parent (N));
2141 when N_Selected_Component =>
2142 return Is_Primary (Parent (N));
2149 -- Start of processing for Validate_Static_Object_Name
2152 if not In_Preelaborated_Unit
2153 or else not Comes_From_Source (N)
2154 or else In_Subprogram_Or_Concurrent_Unit
2155 or else Ekind (Current_Scope) = E_Block
2159 -- Filter out cases where primary is default in a component declaration,
2160 -- discriminant specification, or actual in a record type initialization
2163 -- Initialization call of internal types
2165 elsif Nkind (Parent (N)) = N_Procedure_Call_Statement then
2167 if Present (Parent (Parent (N)))
2168 and then Nkind (Parent (Parent (N))) = N_Freeze_Entity
2173 if Nkind (Name (Parent (N))) = N_Identifier
2174 and then not Comes_From_Source (Entity (Name (Parent (N))))
2180 -- Error if the name is a primary in an expression. The parent must not
2181 -- be an operator, or a selected component or an indexed component that
2182 -- is itself a primary. Entities that are actuals do not need to be
2183 -- checked, because the call itself will be diagnosed. Entities in a
2184 -- generic unit or within a preanalyzed expression are not checked:
2185 -- only their use in executable code matters.
2188 and then (not Inside_A_Generic
2189 or else Present (Enclosing_Generic_Body (N)))
2190 and then not In_Spec_Expression
2192 if Ekind (Entity (N)) = E_Variable
2193 or else Ekind (Entity (N)) in Formal_Object_Kind
2195 Flag_Non_Static_Expr
2196 ("non-static object name in preelaborated unit", N);
2198 -- Give an error for a reference to a nonstatic constant, unless the
2199 -- constant is in another GNAT library unit that is preelaborable.
2201 elsif Ekind (Entity (N)) = E_Constant
2202 and then not Is_Static_Expression (N)
2205 Val := Constant_Value (E);
2207 if In_Internal_Unit (N)
2209 Enclosing_Comp_Unit_Node (N) /= Enclosing_Comp_Unit_Node (E)
2210 and then (Is_Preelaborated (Scope (E))
2211 or else Is_Pure (Scope (E))
2212 or else (Present (Renamed_Object (E))
2213 and then Is_Entity_Name (Renamed_Object (E))
2216 (Scope (Renamed_Object (E)))
2219 (Scope (Renamed_Object (E))))))
2223 -- If the value of the constant is a local variable that renames
2224 -- an aggregate, this is in itself legal. The aggregate may be
2225 -- expanded into a loop, but this does not affect preelaborability
2226 -- in itself. If some aggregate components are non-static, that is
2227 -- to say if they involve non static primaries, they will be
2228 -- flagged when analyzed.
2231 and then Is_Entity_Name (Val)
2232 and then Is_Array_Type (Etype (Val))
2233 and then not Comes_From_Source (Val)
2234 and then Nkind (Original_Node (Val)) = N_Aggregate
2238 -- This is the error case
2241 -- In GNAT mode or Relaxed RM Semantic mode, this is just a
2242 -- warning, to allow it to be judiciously turned off.
2243 -- Otherwise it is a real error.
2245 if GNAT_Mode or Relaxed_RM_Semantics then
2247 ("??non-static constant in preelaborated unit", N);
2249 Flag_Non_Static_Expr
2250 ("non-static constant in preelaborated unit", N);
2255 end Validate_Static_Object_Name;