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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C A T --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Tss; use Exp_Tss;
with Fname; use Fname;
with Lib; use Lib;
with Nlists; use Nlists;
with Opt; use Opt;
with Sem; use Sem;
with Sem_Eval; use Sem_Eval;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
package body Sem_Cat is
-----------------------
-- Local Subprograms --
-----------------------
procedure Check_Categorization_Dependencies
(Unit_Entity : Entity_Id;
Depended_Entity : Entity_Id;
Info_Node : Node_Id;
Is_Subunit : Boolean);
-- This procedure checks that the categorization of a lib unit and that
-- of the depended unit satisfy dependency restrictions.
-- The depended_entity can be the entity in a with_clause item, in which
-- case Info_Node denotes that item. The depended_entity can also be the
-- parent unit of a child unit, in which case Info_Node is the declaration
-- of the child unit. The error message is posted on Info_Node, and is
-- specialized if Is_Subunit is true.
procedure Check_Non_Static_Default_Expr
(Type_Def : Node_Id;
Obj_Decl : Node_Id);
-- Iterate through the component list of a record definition, check
-- that no component is declared with a nonstatic default value.
-- If a nonstatic default exists, report an error on Obj_Decl.
-- Iterate through the component list of a record definition, check
-- that no component is declared with a non-static default value.
function Missing_Read_Write_Attributes (E : Entity_Id) return Boolean;
-- Return True if the entity or one of its subcomponent is an access
-- type which does not have user-defined Read and Write attribute.
function In_RCI_Declaration (N : Node_Id) return Boolean;
-- Determines if a declaration is within the visible part of a Remote
-- Call Interface compilation unit, for semantic checking purposes only,
-- (returns false within an instance and within the package body).
function In_RT_Declaration return Boolean;
-- Determines if current scope is within a Remote Types compilation unit,
-- for semantic checking purposes.
function Is_Non_Remote_Access_Type (E : Entity_Id) return Boolean;
-- Returns true if the entity is a non-remote access type
function In_Shared_Passive_Unit return Boolean;
-- Determines if current scope is within a Shared Passive compilation unit
function Static_Discriminant_Expr (L : List_Id) return Boolean;
-- Iterate through the list of discriminants to check if any of them
-- contains non-static default expression, which is a violation in
-- a preelaborated library unit.
procedure Validate_Remote_Access_Object_Type_Declaration (T : Entity_Id);
-- Check validity of declaration if RCI or RT unit. It should not contain
-- the declaration of an access-to-object type unless it is a
-- general access type that designates a class-wide limited
-- private type. There are also constraints about the primitive
-- subprograms of the class-wide type. RM E.2 (9, 13, 14)
function Is_Recursively_Limited_Private (E : Entity_Id) return Boolean;
-- Return True if E is a limited private type, or if E is a private
-- extension of a type whose parent verifies this property (hence the
-- recursive keyword).
---------------------------------------
-- Check_Categorization_Dependencies --
---------------------------------------
procedure Check_Categorization_Dependencies
(Unit_Entity : Entity_Id;
Depended_Entity : Entity_Id;
Info_Node : Node_Id;
Is_Subunit : Boolean)
is
N : constant Node_Id := Info_Node;
-- Here we define an enumeration type to represent categorization
-- types, ordered so that a unit with a given categorization can
-- only WITH units with lower or equal categorization type.
type Categorization is
(Pure,
Shared_Passive,
Remote_Types,
Remote_Call_Interface,
Preelaborated,
Normal);
Unit_Category : Categorization;
With_Category : Categorization;
function Get_Categorization (E : Entity_Id) return Categorization;
-- Check categorization flags from entity, and return in the form
-- of a corresponding enumeration value.
------------------------
-- Get_Categorization --
------------------------
function Get_Categorization (E : Entity_Id) return Categorization is
begin
if Is_Preelaborated (E) then
return Preelaborated;
-- Ignore Pure specification if set by pragma Pure_Function
elsif Is_Pure (E)
and then not
(Has_Pragma_Pure_Function (E) and not Has_Pragma_Pure (E))
then
return Pure;
elsif Is_Shared_Passive (E) then
return Shared_Passive;
elsif Is_Remote_Types (E) then
return Remote_Types;
elsif Is_Remote_Call_Interface (E) then
return Remote_Call_Interface;
else
return Normal;
end if;
end Get_Categorization;
-- Start of processing for Check_Categorization_Dependencies
begin
-- Intrinsic subprograms are preelaborated, so do not impose any
-- categorization dependencies.
if Is_Intrinsic_Subprogram (Depended_Entity) then
return;
end if;
Unit_Category := Get_Categorization (Unit_Entity);
With_Category := Get_Categorization (Depended_Entity);
-- These messages are wanings in GNAT mode, to allow it to be
-- judiciously turned off. Otherwise it is a real error.
Error_Msg_Warn := GNAT_Mode;
-- Check for possible error
if With_Category > Unit_Category then
-- Special case: Remote_Types and Remote_Call_Interface are allowed
-- to be with'ed in package body.
if (Unit_Category = Remote_Types
or else Unit_Category = Remote_Call_Interface)
and then In_Package_Body (Unit_Entity)
then
null;
-- Here we have an error
else
if Is_Subunit then
Error_Msg_NE
("<subunit cannot depend on& " &
"(parent has wrong categorization)", N, Depended_Entity);
else
Error_Msg_NE
("<cannot depend on& " &
"(wrong categorization)", N, Depended_Entity);
end if;
-- Add further explanation for common cases
case Unit_Category is
when Pure =>
Error_Msg_NE
("\<pure unit cannot depend on non-pure unit",
N, Depended_Entity);
when Preelaborated =>
Error_Msg_NE
("\<preelaborated unit cannot depend on " &
"non-preelaborated unit",
N, Depended_Entity);
when others =>
null;
end case;
end if;
end if;
end Check_Categorization_Dependencies;
-----------------------------------
-- Check_Non_Static_Default_Expr --
-----------------------------------
procedure Check_Non_Static_Default_Expr
(Type_Def : Node_Id;
Obj_Decl : Node_Id)
is
Recdef : Node_Id;
Component_Decl : Node_Id;
begin
if Nkind (Type_Def) = N_Derived_Type_Definition then
Recdef := Record_Extension_Part (Type_Def);
if No (Recdef) then
return;
end if;
else
Recdef := Type_Def;
end if;
-- Check that component declarations do not involve:
-- a. a non-static default expression, where the object is
-- declared to be default initialized.
-- b. a dynamic Itype (discriminants and constraints)
if Null_Present (Recdef) then
return;
else
Component_Decl := First (Component_Items (Component_List (Recdef)));
end if;
while Present (Component_Decl)
and then Nkind (Component_Decl) = N_Component_Declaration
loop
if Present (Expression (Component_Decl))
and then Nkind (Expression (Component_Decl)) /= N_Null
and then not Is_Static_Expression (Expression (Component_Decl))
then
Error_Msg_Sloc := Sloc (Component_Decl);
Error_Msg_F
("object in preelaborated unit has non-static default#",
Obj_Decl);
-- Fix this later ???
-- elsif Has_Dynamic_Itype (Component_Decl) then
-- Error_Msg_N
-- ("dynamic type discriminant," &
-- " constraint in preelaborated unit",
-- Component_Decl);
end if;
Next (Component_Decl);
end loop;
end Check_Non_Static_Default_Expr;
---------------------------
-- In_Preelaborated_Unit --
---------------------------
function In_Preelaborated_Unit return Boolean is
Unit_Entity : constant Entity_Id := Current_Scope;
Unit_Kind : constant Node_Kind :=
Nkind (Unit (Cunit (Current_Sem_Unit)));
begin
-- There are no constraints on body of remote_call_interface or
-- remote_types packages..
return (Unit_Entity /= Standard_Standard)
and then (Is_Preelaborated (Unit_Entity)
or else Is_Pure (Unit_Entity)
or else Is_Shared_Passive (Unit_Entity)
or else
((Is_Remote_Types (Unit_Entity)
or else Is_Remote_Call_Interface (Unit_Entity))
and then Ekind (Unit_Entity) = E_Package
and then Unit_Kind /= N_Package_Body
and then not In_Package_Body (Unit_Entity)
and then not In_Instance));
end In_Preelaborated_Unit;
------------------
-- In_Pure_Unit --
------------------
function In_Pure_Unit return Boolean is
begin
return Is_Pure (Current_Scope);
end In_Pure_Unit;
------------------------
-- In_RCI_Declaration --
------------------------
function In_RCI_Declaration (N : Node_Id) return Boolean is
Unit_Entity : constant Entity_Id := Current_Scope;
Unit_Kind : constant Node_Kind :=
Nkind (Unit (Cunit (Current_Sem_Unit)));
begin
-- There are no restrictions on the private part or body
-- of an RCI unit.
return Is_Remote_Call_Interface (Unit_Entity)
and then (Ekind (Unit_Entity) = E_Package
or else Ekind (Unit_Entity) = E_Generic_Package)
and then Unit_Kind /= N_Package_Body
and then List_Containing (N) =
Visible_Declarations
(Specification (Unit_Declaration_Node (Unit_Entity)))
and then not In_Package_Body (Unit_Entity)
and then not In_Instance;
end In_RCI_Declaration;
-----------------------
-- In_RT_Declaration --
-----------------------
function In_RT_Declaration return Boolean is
Unit_Entity : constant Entity_Id := Current_Scope;
Unit_Kind : constant Node_Kind :=
Nkind (Unit (Cunit (Current_Sem_Unit)));
begin
-- There are no restrictions on the body of a Remote Types unit
return Is_Remote_Types (Unit_Entity)
and then (Ekind (Unit_Entity) = E_Package
or else Ekind (Unit_Entity) = E_Generic_Package)
and then Unit_Kind /= N_Package_Body
and then not In_Package_Body (Unit_Entity)
and then not In_Instance;
end In_RT_Declaration;
----------------------------
-- In_Shared_Passive_Unit --
----------------------------
function In_Shared_Passive_Unit return Boolean is
Unit_Entity : constant Entity_Id := Current_Scope;
begin
return Is_Shared_Passive (Unit_Entity);
end In_Shared_Passive_Unit;
---------------------------------------
-- In_Subprogram_Task_Protected_Unit --
---------------------------------------
function In_Subprogram_Task_Protected_Unit return Boolean is
E : Entity_Id;
begin
-- The following is to verify that a declaration is inside
-- subprogram, generic subprogram, task unit, protected unit.
-- Used to validate if a lib. unit is Pure. RM 10.2.1(16).
-- Use scope chain to check successively outer scopes
E := Current_Scope;
loop
if Is_Subprogram (E)
or else
Is_Generic_Subprogram (E)
or else
Is_Concurrent_Type (E)
then
return True;
elsif E = Standard_Standard then
return False;
end if;
E := Scope (E);
end loop;
end In_Subprogram_Task_Protected_Unit;
-------------------------------
-- Is_Non_Remote_Access_Type --
-------------------------------
function Is_Non_Remote_Access_Type (E : Entity_Id) return Boolean is
begin
return Is_Access_Type (E)
and then not Is_Remote_Access_To_Class_Wide_Type (E)
and then not Is_Remote_Access_To_Subprogram_Type (E);
end Is_Non_Remote_Access_Type;
------------------------------------
-- Is_Recursively_Limited_Private --
------------------------------------
function Is_Recursively_Limited_Private (E : Entity_Id) return Boolean is
P : constant Node_Id := Parent (E);
begin
if Nkind (P) = N_Private_Type_Declaration
and then Is_Limited_Record (E)
then
return True;
elsif Nkind (P) = N_Private_Extension_Declaration then
return Is_Recursively_Limited_Private (Etype (E));
elsif Nkind (P) = N_Formal_Type_Declaration
and then Ekind (E) = E_Record_Type_With_Private
and then Is_Generic_Type (E)
and then Is_Limited_Record (E)
then
return True;
else
return False;
end if;
end Is_Recursively_Limited_Private;
----------------------------------
-- Missing_Read_Write_Attribute --
----------------------------------
function Missing_Read_Write_Attributes (E : Entity_Id) return Boolean is
Component : Entity_Id;
Component_Type : Entity_Id;
function Has_Read_Write_Attributes (E : Entity_Id) return Boolean;
-- Return True if entity has Read and Write attributes
-------------------------------
-- Has_Read_Write_Attributes --
-------------------------------
function Has_Read_Write_Attributes (E : Entity_Id) return Boolean is
Rep_Item : Node_Id := First_Rep_Item (E);
Read_Attribute : Boolean := False;
Write_Attribute : Boolean := False;
begin
-- We start from the declaration node and then loop until the end
-- of the list until we find those two attribute definition clauses.
while Present (Rep_Item) loop
if Chars (Rep_Item) = Name_Read then
Read_Attribute := True;
elsif Chars (Rep_Item) = Name_Write then
Write_Attribute := True;
end if;
if Read_Attribute and Write_Attribute then
return True;
end if;
Next_Rep_Item (Rep_Item);
end loop;
return False;
end Has_Read_Write_Attributes;
-- Start of processing for Missing_Read_Write_Attributes
begin
if Has_Read_Write_Attributes (E) then
return False;
elsif Is_Non_Remote_Access_Type (E) then
return True;
end if;
if Is_Record_Type (E) then
Component := First_Entity (E);
while Present (Component) loop
Component_Type := Etype (Component);
if (Is_Non_Remote_Access_Type (Component_Type)
or else Is_Record_Type (Component_Type))
and then Missing_Read_Write_Attributes (Component_Type)
then
return True;
end if;
Next_Entity (Component);
end loop;
end if;
return False;
end Missing_Read_Write_Attributes;
-------------------------------------
-- Set_Categorization_From_Pragmas --
-------------------------------------
procedure Set_Categorization_From_Pragmas (N : Node_Id) is
P : constant Node_Id := Parent (N);
S : constant Entity_Id := Current_Scope;
procedure Set_Parents (Visibility : Boolean);
-- If this is a child instance, the parents are not immediately
-- visible during analysis. Make them momentarily visible so that
-- the argument of the pragma can be resolved properly, and reset
-- afterwards.
procedure Set_Parents (Visibility : Boolean) is
Par : Entity_Id := Scope (S);
begin
while Present (Par) and then Par /= Standard_Standard loop
Set_Is_Immediately_Visible (Par, Visibility);
Par := Scope (Par);
end loop;
end Set_Parents;
begin
-- Deal with categorization pragmas in Pragmas of Compilation_Unit.
-- The purpose is to set categorization flags before analyzing the
-- unit itself, so as to diagnose violations of categorization as
-- we process each declaration, even though the pragma appears after
-- the unit.
if Nkind (P) /= N_Compilation_Unit then
return;
end if;
declare
PN : Node_Id := First (Pragmas_After (Aux_Decls_Node (P)));
begin
if Is_Child_Unit (S)
and then Is_Generic_Instance (S)
then
Set_Parents (True);
end if;
while Present (PN) loop
-- Skip implicit types that may have been introduced by
-- previous analysis.
if Nkind (PN) = N_Pragma then
case Get_Pragma_Id (Chars (PN)) is
when Pragma_All_Calls_Remote |
Pragma_Preelaborate |
Pragma_Pure |
Pragma_Remote_Call_Interface |
Pragma_Remote_Types |
Pragma_Shared_Passive => Analyze (PN);
when others => null;
end case;
end if;
Next (PN);
end loop;
if Is_Child_Unit (S)
and then Is_Generic_Instance (S)
then
Set_Parents (False);
end if;
end;
end Set_Categorization_From_Pragmas;
-----------------------------------
-- Set_Categorization_From_Scope --
-----------------------------------
procedure Set_Categorization_From_Scope (E : Entity_Id; Scop : Entity_Id) is
Declaration : Node_Id := Empty;
Specification : Node_Id := Empty;
begin
Set_Is_Pure (E,
Is_Pure (Scop) and then Is_Library_Level_Entity (E));
if not Is_Remote_Call_Interface (E) then
if Ekind (E) in Subprogram_Kind then
Declaration := Unit_Declaration_Node (E);
if False
or else Nkind (Declaration) = N_Subprogram_Body
or else Nkind (Declaration) = N_Subprogram_Renaming_Declaration
then
Specification := Corresponding_Spec (Declaration);
end if;
end if;
-- A subprogram body or renaming-as-body is a remote call
-- interface if it serves as the completion of a subprogram
-- declaration that is a remote call interface.
if Nkind (Specification) in N_Entity then
Set_Is_Remote_Call_Interface
(E, Is_Remote_Call_Interface (Specification));
-- A subprogram declaration is a remote call interface when it is
-- declared within the visible part of, or declared by, a library
-- unit declaration that is a remote call interface.
else
Set_Is_Remote_Call_Interface
(E, Is_Remote_Call_Interface (Scop)
and then not (In_Private_Part (Scop)
or else In_Package_Body (Scop)));
end if;
end if;
Set_Is_Remote_Types (E, Is_Remote_Types (Scop));
end Set_Categorization_From_Scope;
------------------------------
-- Static_Discriminant_Expr --
------------------------------
-- We need to accomodate a Why_Not_Static call somehow here ???
function Static_Discriminant_Expr (L : List_Id) return Boolean is
Discriminant_Spec : Node_Id;
begin
Discriminant_Spec := First (L);
while Present (Discriminant_Spec) loop
if Present (Expression (Discriminant_Spec))
and then not Is_Static_Expression (Expression (Discriminant_Spec))
then
return False;
end if;
Next (Discriminant_Spec);
end loop;
return True;
end Static_Discriminant_Expr;
--------------------------------------
-- Validate_Access_Type_Declaration --
--------------------------------------
procedure Validate_Access_Type_Declaration (T : Entity_Id; N : Node_Id) is
Def : constant Node_Id := Type_Definition (N);
begin
case Nkind (Def) is
-- Access to subprogram case
when N_Access_To_Subprogram_Definition =>
-- A pure library_item must not contain the declaration of a
-- named access type, except within a subprogram, generic
-- subprogram, task unit, or protected unit (RM 10.2.1(16)).
-- This test is skipped in Ada 2005 (see AI-366)
if Ada_Version < Ada_05
and then Comes_From_Source (T)
and then In_Pure_Unit
and then not In_Subprogram_Task_Protected_Unit
then
Error_Msg_N ("named access type not allowed in pure unit", T);
end if;
-- Access to object case
when N_Access_To_Object_Definition =>
if Comes_From_Source (T)
and then In_Pure_Unit
and then not In_Subprogram_Task_Protected_Unit
then
-- We can't give the message yet, since the type is not frozen
-- and in Ada 2005 mode, access types are allowed in pure units
-- if the type has no storage pool (see AI-366). So we set a
-- flag which will be checked at freeze time.
Set_Is_Pure_Unit_Access_Type (T);
end if;
-- Check for RCI or RT unit type declaration. It should not
-- contain the declaration of an access-to-object type unless it
-- is a general access type that designates a class-wide limited
-- private type. There are also constraints about the primitive
-- subprograms of the class-wide type.
Validate_Remote_Access_Object_Type_Declaration (T);
-- Check for shared passive unit type declaration. It should
-- not contain the declaration of access to class wide type,
-- access to task type and access to protected type with entry.
Validate_SP_Access_Object_Type_Decl (T);
when others =>
null;
end case;
-- Set categorization flag from package on entity as well, to allow
-- easy checks later on for required validations of RCI or RT units.
-- This is only done for entities that are in the original source.
if Comes_From_Source (T)
and then not (In_Package_Body (Scope (T))
or else In_Private_Part (Scope (T)))
then
Set_Is_Remote_Call_Interface
(T, Is_Remote_Call_Interface (Scope (T)));
Set_Is_Remote_Types
(T, Is_Remote_Types (Scope (T)));
end if;
end Validate_Access_Type_Declaration;
----------------------------
-- Validate_Ancestor_Part --
----------------------------
procedure Validate_Ancestor_Part (N : Node_Id) is
A : constant Node_Id := Ancestor_Part (N);
T : constant Entity_Id := Entity (A);
begin
if In_Preelaborated_Unit
and then not In_Subprogram_Or_Concurrent_Unit
and then (not Inside_A_Generic
or else Present (Enclosing_Generic_Body (N)))
then
-- We relax the restriction of 10.2.1(9) within GNAT
-- units to allow packages such as Ada.Strings.Unbounded
-- to be implemented (i.p., Null_Unbounded_String).
-- (There are ACVC tests that check that the restriction
-- is enforced, but note that AI-161, once approved,
-- will relax the restriction prohibiting default-
-- initialized objects of private and controlled
-- types.)
if Is_Private_Type (T)
and then not Is_Internal_File_Name
(Unit_File_Name (Get_Source_Unit (N)))
then
Error_Msg_N
("private ancestor type not allowed in preelaborated unit", A);
elsif Is_Record_Type (T) then
if Nkind (Parent (T)) = N_Full_Type_Declaration then
Check_Non_Static_Default_Expr
(Type_Definition (Parent (T)), A);
end if;
end if;
end if;
end Validate_Ancestor_Part;
----------------------------------------
-- Validate_Categorization_Dependency --
----------------------------------------
procedure Validate_Categorization_Dependency
(N : Node_Id;
E : Entity_Id)
is
K : constant Node_Kind := Nkind (N);
P : Node_Id := Parent (N);
U : Entity_Id := E;
Is_Subunit : constant Boolean := Nkind (P) = N_Subunit;
begin
-- Only validate library units and subunits. For subunits, checks
-- concerning withed units apply to the parent compilation unit.
if Is_Subunit then
P := Parent (P);
U := Scope (E);
while Present (U)
and then not Is_Compilation_Unit (U)
and then not Is_Child_Unit (U)
loop
U := Scope (U);
end loop;
end if;
if Nkind (P) /= N_Compilation_Unit then
return;
end if;
-- Body of RCI unit does not need validation
if Is_Remote_Call_Interface (E)
and then (Nkind (N) = N_Package_Body
or else Nkind (N) = N_Subprogram_Body)
then
return;
end if;
-- Ada 2005 (AI-50217): Process explicit non-limited with_clauses
declare
Item : Node_Id;
Entity_Of_Withed : Entity_Id;
begin
Item := First (Context_Items (P));
while Present (Item) loop
if Nkind (Item) = N_With_Clause
and then not (Implicit_With (Item)
or else Limited_Present (Item))
then
Entity_Of_Withed := Entity (Name (Item));
Check_Categorization_Dependencies
(U, Entity_Of_Withed, Item, Is_Subunit);
end if;
Next (Item);
end loop;
end;
-- Child depends on parent; therefore parent should also be categorized
-- and satify the dependency hierarchy.
-- Check if N is a child spec
if (K in N_Generic_Declaration or else
K in N_Generic_Instantiation or else
K in N_Generic_Renaming_Declaration or else
K = N_Package_Declaration or else
K = N_Package_Renaming_Declaration or else
K = N_Subprogram_Declaration or else
K = N_Subprogram_Renaming_Declaration)
and then Present (Parent_Spec (N))
then
Check_Categorization_Dependencies (E, Scope (E), N, False);
-- Verify that public child of an RCI library unit must also be an
-- RCI library unit (RM E.2.3(15)).
if Is_Remote_Call_Interface (Scope (E))
and then not Private_Present (P)
and then not Is_Remote_Call_Interface (E)
then
Error_Msg_N ("public child of rci unit must also be rci unit", N);
end if;
end if;
end Validate_Categorization_Dependency;
--------------------------------
-- Validate_Controlled_Object --
--------------------------------
procedure Validate_Controlled_Object (E : Entity_Id) is
begin
-- For now, never apply this check for internal GNAT units, since we
-- have a number of cases in the library where we are stuck with objects
-- of this type, and the RM requires Preelaborate.
-- For similar reasons, we only do this check for source entities, since
-- we generate entities of this type in some situations.
-- Note that the 10.2.1(9) restrictions are not relevant to us anyway.
-- We have to enforce them for RM compatibility, but we have no trouble
-- accepting these objects and doing the right thing. Note that there is
-- no requirement that Preelaborate not actually generate any code!
if In_Preelaborated_Unit
and then not Debug_Flag_PP
and then Comes_From_Source (E)
and then not
Is_Internal_File_Name (Unit_File_Name (Get_Source_Unit (E)))
and then (not Inside_A_Generic
or else Present (Enclosing_Generic_Body (E)))
and then not Is_Protected_Type (Etype (E))
then
Error_Msg_N
("library level controlled object not allowed in " &
"preelaborated unit", E);
end if;
end Validate_Controlled_Object;
--------------------------------------
-- Validate_Null_Statement_Sequence --
--------------------------------------
procedure Validate_Null_Statement_Sequence (N : Node_Id) is
Item : Node_Id;
begin
if In_Preelaborated_Unit then
Item := First (Statements (Handled_Statement_Sequence (N)));
while Present (Item) loop
if Nkind (Item) /= N_Label
and then Nkind (Item) /= N_Null_Statement
then
-- In GNAT mode, this is a warning, allowing the run-time
-- to judiciously bypass this error condition.
Error_Msg_Warn := GNAT_Mode;
Error_Msg_N
("<statements not allowed in preelaborated unit", Item);
exit;
end if;
Next (Item);
end loop;
end if;
end Validate_Null_Statement_Sequence;
---------------------------------
-- Validate_Object_Declaration --
---------------------------------
procedure Validate_Object_Declaration (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (N);
E : constant Node_Id := Expression (N);
Odf : constant Node_Id := Object_Definition (N);
T : constant Entity_Id := Etype (Id);
begin
-- Verify that any access to subprogram object does not have in its
-- subprogram profile access type parameters or limited parameters
-- without Read and Write attributes (E.2.3(13)).
Validate_RCI_Subprogram_Declaration (N);
-- Check that if we are in preelaborated elaboration code, then we
-- do not have an instance of a default initialized private, task or
-- protected object declaration which would violate (RM 10.2.1(9)).
-- Note that constants are never default initialized (and the test
-- below also filters out deferred constants). A variable is default
-- initialized if it does *not* have an initialization expression.
-- Filter out cases that are not declaration of a variable from source
if Nkind (N) /= N_Object_Declaration
or else Constant_Present (N)
or else not Comes_From_Source (Id)
then
return;
end if;
-- Exclude generic specs from the checks (this will get rechecked
-- on instantiations).
if Inside_A_Generic
and then No (Enclosing_Generic_Body (Id))
then
return;
end if;
-- Required checks for declaration that is in a preelaborated
-- package and is not within some subprogram.
if In_Preelaborated_Unit
and then not In_Subprogram_Or_Concurrent_Unit
then
-- Check for default initialized variable case. Note that in
-- accordance with (RM B.1(24)) imported objects are not
-- subject to default initialization.
if No (E) and then not Is_Imported (Id) then
declare
Ent : Entity_Id := T;
begin
-- An array whose component type is a record with nonstatic
-- default expressions is a violation, so we get the array's
-- component type.
if Is_Array_Type (Ent) then
declare
Comp_Type : Entity_Id := Component_Type (Ent);
begin
while Is_Array_Type (Comp_Type) loop
Comp_Type := Component_Type (Comp_Type);
end loop;
Ent := Comp_Type;
end;
end if;
-- Object decl. that is of record type and has no default expr.
-- should check if there is any non-static default expression
-- in component decl. of the record type decl.
if Is_Record_Type (Ent) then
if Nkind (Parent (Ent)) = N_Full_Type_Declaration then
Check_Non_Static_Default_Expr
(Type_Definition (Parent (Ent)), N);
elsif Nkind (Odf) = N_Subtype_Indication
and then not Is_Array_Type (T)
and then not Is_Private_Type (T)
then
Check_Non_Static_Default_Expr (Type_Definition
(Parent (Entity (Subtype_Mark (Odf)))), N);
end if;
end if;
-- We relax the restriction of 10.2.1(9) within GNAT
-- units. (There are ACVC tests that check that the
-- restriction is enforced, but note that AI-161,
-- once approved, will relax the restriction prohibiting
-- default-initialized objects of private types, and
-- will recommend a pragma for marking private types.)
if (Is_Private_Type (Ent)
or else Depends_On_Private (Ent))
and then not Is_Internal_File_Name
(Unit_File_Name (Get_Source_Unit (N)))
then
Error_Msg_N
("private object not allowed in preelaborated unit", N);
return;
-- Access to Task or Protected type
elsif Is_Entity_Name (Odf)
and then Present (Etype (Odf))
and then Is_Access_Type (Etype (Odf))
then
Ent := Designated_Type (Etype (Odf));
elsif Is_Entity_Name (Odf) then
Ent := Entity (Odf);
elsif Nkind (Odf) = N_Subtype_Indication then
Ent := Etype (Subtype_Mark (Odf));
elsif
Nkind (Odf) = N_Constrained_Array_Definition
then
Ent := Component_Type (T);
-- else
-- return;
end if;
if Is_Task_Type (Ent)
or else (Is_Protected_Type (Ent) and then Has_Entries (Ent))
then
Error_Msg_N
("concurrent object not allowed in preelaborated unit",
N);
return;
end if;
end;
end if;
-- Non-static discriminant not allowed in preelaborayted unit
if Is_Record_Type (Etype (Id)) then
declare
ET : constant Entity_Id := Etype (Id);
EE : constant Entity_Id := Etype (Etype (Id));
PEE : Node_Id;
begin
if Has_Discriminants (ET)
and then Present (EE)
then
PEE := Parent (EE);
if Nkind (PEE) = N_Full_Type_Declaration
and then not Static_Discriminant_Expr
(Discriminant_Specifications (PEE))
then
Error_Msg_N
("non-static discriminant in preelaborated unit",
PEE);
end if;
end if;
end;
end if;
end if;
-- A pure library_item must not contain the declaration of any
-- variable except within a subprogram, generic subprogram, task
-- unit or protected unit (RM 10.2.1(16)).
if In_Pure_Unit
and then not In_Subprogram_Task_Protected_Unit
then
Error_Msg_N ("declaration of variable not allowed in pure unit", N);
-- The visible part of an RCI library unit must not contain the
-- declaration of a variable (RM E.1.3(9))
elsif In_RCI_Declaration (N) then
Error_Msg_N ("declaration of variable not allowed in rci unit", N);
-- The visible part of a Shared Passive library unit must not contain
-- the declaration of a variable (RM E.2.2(7))
elsif In_RT_Declaration then
Error_Msg_N
("variable declaration not allowed in remote types unit", N);
end if;
end Validate_Object_Declaration;
-------------------------------
-- Validate_RCI_Declarations --
-------------------------------
procedure Validate_RCI_Declarations (P : Entity_Id) is
E : Entity_Id;
begin
E := First_Entity (P);
while Present (E) loop
if Comes_From_Source (E) then
if Is_Limited_Type (E) then
Error_Msg_N
("Limited type not allowed in rci unit", Parent (E));
Explain_Limited_Type (E, Parent (E));
elsif Ekind (E) = E_Generic_Function
or else Ekind (E) = E_Generic_Package
or else Ekind (E) = E_Generic_Procedure
then
Error_Msg_N ("generic declaration not allowed in rci unit",
Parent (E));
elsif (Ekind (E) = E_Function
or else Ekind (E) = E_Procedure)
and then Has_Pragma_Inline (E)
then
Error_Msg_N
("inlined subprogram not allowed in rci unit", Parent (E));
-- Inner packages that are renamings need not be checked.
-- Generic RCI packages are subject to the checks, but
-- entities that come from formal packages are not part of the
-- visible declarations of the package and are not checked.
elsif Ekind (E) = E_Package then
if Present (Renamed_Entity (E)) then
null;
elsif Ekind (P) /= E_Generic_Package
or else List_Containing (Unit_Declaration_Node (E)) /=
Generic_Formal_Declarations
(Unit_Declaration_Node (P))
then
Validate_RCI_Declarations (E);
end if;
end if;
end if;
Next_Entity (E);
end loop;
end Validate_RCI_Declarations;
-----------------------------------------
-- Validate_RCI_Subprogram_Declaration --
-----------------------------------------
procedure Validate_RCI_Subprogram_Declaration (N : Node_Id) is
K : constant Node_Kind := Nkind (N);
Profile : List_Id;
Id : Node_Id;
Param_Spec : Node_Id;
Param_Type : Entity_Id;
Base_Param_Type : Entity_Id;
Base_Under_Type : Entity_Id;
Type_Decl : Node_Id;
Error_Node : Node_Id := N;
begin
-- There are two possible cases in which this procedure is called:
-- 1. called from Analyze_Subprogram_Declaration.
-- 2. called from Validate_Object_Declaration (access to subprogram).
if not In_RCI_Declaration (N) then
return;
end if;
if K = N_Subprogram_Declaration then
Profile := Parameter_Specifications (Specification (N));
else pragma Assert (K = N_Object_Declaration);
Id := Defining_Identifier (N);
if Nkind (Id) = N_Defining_Identifier
and then Nkind (Parent (Etype (Id))) = N_Full_Type_Declaration
and then Ekind (Etype (Id)) = E_Access_Subprogram_Type
then
Profile :=
Parameter_Specifications (Type_Definition (Parent (Etype (Id))));
else
return;
end if;
end if;
-- Iterate through the parameter specification list, checking that
-- no access parameter and no limited type parameter in the list.
-- RM E.2.3 (14)
if Present (Profile) then
Param_Spec := First (Profile);
while Present (Param_Spec) loop
Param_Type := Etype (Defining_Identifier (Param_Spec));
Type_Decl := Parent (Param_Type);
if Ekind (Param_Type) = E_Anonymous_Access_Type then
if K = N_Subprogram_Declaration then
Error_Node := Param_Spec;
end if;
-- Report error only if declaration is in source program
if Comes_From_Source
(Defining_Entity (Specification (N)))
then
Error_Msg_N
("subprogram in rci unit cannot have access parameter",
Error_Node);
end if;
-- For limited private type parameter, we check only the
-- private declaration and ignore full type declaration,
-- unless this is the only declaration for the type, eg.
-- as a limited record.
elsif Is_Limited_Type (Param_Type)
and then (Nkind (Type_Decl) = N_Private_Type_Declaration
or else
(Nkind (Type_Decl) = N_Full_Type_Declaration
and then not (Has_Private_Declaration (Param_Type))
and then Comes_From_Source (N)))
then
-- A limited parameter is legal only if user-specified Read and
-- Write attributes exist for it. Second part of RM E.2.3 (14).
if No (Full_View (Param_Type))
and then Ekind (Param_Type) /= E_Record_Type
then
-- Type does not have completion yet, so if declared in in
-- the current RCI scope it is illegal, and will be flagged
-- subsequently.
return;
end if;
-- In Ada 95 the rules permit using a limited type that has
-- user-specified Read and Write attributes that are specified
-- in the private part of the package, whereas Ada 2005
-- (AI-240) revises this to require the attributes to be
-- "available" (implying that the attribute clauses must be
-- visible to the RCI client). The Ada 95 rules violate the
-- contract model for privacy, but we support both semantics
-- for now for compatibility (note that ACATS test BXE2009
-- checks a case that conforms to the Ada 95 rules but is
-- illegal in Ada 2005).
Base_Param_Type := Base_Type (Param_Type);
Base_Under_Type := Base_Type (Underlying_Type
(Base_Param_Type));
if (Ada_Version < Ada_05
and then
(No (TSS (Base_Param_Type, TSS_Stream_Read))
or else
No (TSS (Base_Param_Type, TSS_Stream_Write)))
and then
(No (TSS (Base_Under_Type, TSS_Stream_Read))
or else
No (TSS (Base_Under_Type, TSS_Stream_Write))))
or else
(Ada_Version >= Ada_05
and then
(No (TSS (Base_Param_Type, TSS_Stream_Read))
or else
No (TSS (Base_Param_Type, TSS_Stream_Write))
or else
Is_Hidden (TSS (Base_Param_Type, TSS_Stream_Read))
or else
Is_Hidden (TSS (Base_Param_Type, TSS_Stream_Write))))
then
if K = N_Subprogram_Declaration then
Error_Node := Param_Spec;
end if;
if Ada_Version >= Ada_05 then
Error_Msg_N
("limited parameter in rci unit "
& "must have visible read/write attributes ",
Error_Node);
else
Error_Msg_N
("limited parameter in rci unit "
& "must have read/write attributes ",
Error_Node);
end if;
Explain_Limited_Type (Param_Type, Error_Node);
end if;
end if;
Next (Param_Spec);
end loop;
end if;
end Validate_RCI_Subprogram_Declaration;
----------------------------------------------------
-- Validate_Remote_Access_Object_Type_Declaration --
----------------------------------------------------
procedure Validate_Remote_Access_Object_Type_Declaration (T : Entity_Id) is
Direct_Designated_Type : Entity_Id;
Desig_Type : Entity_Id;
Primitive_Subprograms : Elist_Id;
Subprogram : Elmt_Id;
Subprogram_Node : Node_Id;
Profile : List_Id;
Param_Spec : Node_Id;
Param_Type : Entity_Id;
begin
-- We are called from Analyze_Type_Declaration, and the Nkind
-- of the given node is N_Access_To_Object_Definition.
if not Comes_From_Source (T)
or else (not In_RCI_Declaration (Parent (T))
and then not In_RT_Declaration)
then
return;
end if;
-- An access definition in the private part of a Remote Types package
-- may be legal if it has user-defined Read and Write attributes. This
-- will be checked at the end of the package spec processing.
if In_RT_Declaration and then In_Private_Part (Scope (T)) then
return;
end if;
-- Check RCI or RT unit type declaration. It may not contain
-- the declaration of an access-to-object type unless it is a
-- general access type that designates a class-wide limited
-- private type. There are also constraints about the primitive
-- subprograms of the class-wide type (RM E.2.3(14)).
if Ekind (T) /= E_General_Access_Type
or else Ekind (Designated_Type (T)) /= E_Class_Wide_Type
then
if In_RCI_Declaration (Parent (T)) then
Error_Msg_N
("access type in Remote_Call_Interface unit must be " &
"general access", T);
else
Error_Msg_N ("access type in Remote_Types unit must be " &
"general access", T);
end if;
Error_Msg_N ("\to class-wide type", T);
return;
end if;
Direct_Designated_Type := Designated_Type (T);
Desig_Type := Etype (Direct_Designated_Type);
if not Is_Recursively_Limited_Private (Desig_Type) then
Error_Msg_N
("error in designated type of remote access to class-wide type", T);
Error_Msg_N
("\must be tagged limited private or private extension of type", T);
return;
end if;
Primitive_Subprograms := Primitive_Operations (Desig_Type);
Subprogram := First_Elmt (Primitive_Subprograms);
while Subprogram /= No_Elmt loop
Subprogram_Node := Node (Subprogram);
if not Comes_From_Source (Subprogram_Node) then
goto Next_Subprogram;
end if;
Profile := Parameter_Specifications (Parent (Subprogram_Node));
-- Profile must exist, otherwise not primitive operation
Param_Spec := First (Profile);
while Present (Param_Spec) loop
-- Now find out if this parameter is a controlling parameter
Param_Type := Parameter_Type (Param_Spec);
if (Nkind (Param_Type) = N_Access_Definition
and then Etype (Subtype_Mark (Param_Type)) = Desig_Type)
or else (Nkind (Param_Type) /= N_Access_Definition
and then Etype (Param_Type) = Desig_Type)
then
-- It is a controlling parameter, so specific checks below
-- do not apply.
null;
elsif
Nkind (Param_Type) = N_Access_Definition
then
-- From RM E.2.2(14), no access parameter other than
-- controlling ones may be used.
Error_Msg_N
("non-controlling access parameter", Param_Spec);
elsif
Is_Limited_Type (Etype (Defining_Identifier (Param_Spec)))
then
-- Not a controlling parameter, so type must have Read
-- and Write attributes.
if Nkind (Param_Type) in N_Has_Etype
and then Nkind (Parent (Etype (Param_Type))) =
N_Private_Type_Declaration
then
Param_Type := Etype (Param_Type);
if No (TSS (Param_Type, TSS_Stream_Read))
or else
No (TSS (Param_Type, TSS_Stream_Write))
then
Error_Msg_N
("limited formal must have Read and Write attributes",
Param_Spec);
Explain_Limited_Type
(Etype (Defining_Identifier (Param_Spec)), Param_Spec);
end if;
end if;
end if;
-- Check next parameter in this subprogram
Next (Param_Spec);
end loop;
<<Next_Subprogram>>
Next_Elmt (Subprogram);
end loop;
-- Now this is an RCI unit access-to-class-wide-limited-private type
-- declaration. Set the type entity to be Is_Remote_Call_Interface to
-- optimize later checks by avoiding tree traversal to find out if this
-- entity is inside an RCI unit.
Set_Is_Remote_Call_Interface (T);
end Validate_Remote_Access_Object_Type_Declaration;
-----------------------------------------------
-- Validate_Remote_Access_To_Class_Wide_Type --
-----------------------------------------------
procedure Validate_Remote_Access_To_Class_Wide_Type (N : Node_Id) is
K : constant Node_Kind := Nkind (N);
PK : constant Node_Kind := Nkind (Parent (N));
E : Entity_Id;
begin
-- This subprogram enforces the checks in (RM E.2.2(8)) for certain uses
-- of class-wide limited private types.
-- Storage_Pool and Storage_Size are not defined for such types
--
-- The expected type of allocator must not not be such a type.
-- The actual parameter of generic instantiation must not be such a
-- type if the formal parameter is of an access type.
-- On entry, there are five cases
-- 1. called from sem_attr Analyze_Attribute where attribute name is
-- either Storage_Pool or Storage_Size.
-- 2. called from exp_ch4 Expand_N_Allocator
-- 3. called from sem_ch12 Analyze_Associations
-- 4. called from sem_ch4 Analyze_Explicit_Dereference
-- 5. called from sem_res Resolve_Actuals
if K = N_Attribute_Reference then
E := Etype (Prefix (N));
if Is_Remote_Access_To_Class_Wide_Type (E) then
Error_Msg_N ("incorrect attribute of remote operand", N);
return;
end if;
elsif K = N_Allocator then
E := Etype (N);
if Is_Remote_Access_To_Class_Wide_Type (E) then
Error_Msg_N ("incorrect expected remote type of allocator", N);
return;
end if;
elsif K in N_Has_Entity then
E := Entity (N);
if Is_Remote_Access_To_Class_Wide_Type (E) then
Error_Msg_N ("incorrect remote type generic actual", N);
return;
end if;
-- This subprogram also enforces the checks in E.2.2(13). A value of
-- such type must not be dereferenced unless as controlling operand of a
-- dispatching call.
elsif K = N_Explicit_Dereference
and then (Comes_From_Source (N)
or else (Nkind (Original_Node (N)) = N_Selected_Component
and then Comes_From_Source (Original_Node (N))))
then
E := Etype (Prefix (N));
-- If the class-wide type is not a remote one, the restrictions
-- do not apply.
if not Is_Remote_Access_To_Class_Wide_Type (E) then
return;
end if;
-- If we have a true dereference that comes from source and that
-- is a controlling argument for a dispatching call, accept it.
-- LLVM local begin
if Is_Actual_Parameter (N)
-- LLVM local end
and then Is_Controlling_Actual (N)
then
return;
end if;
-- If we are just within a procedure or function call and the
-- dereference has not been analyzed, return because this procedure
-- will be called again from sem_res Resolve_Actuals.
if Is_Actual_Parameter (N)
and then not Analyzed (N)
then
return;
end if;
-- The following is to let the compiler generated tags check pass
-- through without error message. This is a bit kludgy isn't there
-- some better way of making this exclusion ???
if (PK = N_Selected_Component
and then Present (Parent (Parent (N)))
and then Nkind (Parent (Parent (N))) = N_Op_Ne)
or else (PK = N_Unchecked_Type_Conversion
and then Present (Parent (Parent (N)))
and then
Nkind (Parent (Parent (N))) = N_Selected_Component)
then
return;
end if;
-- The following code is needed for expansion of RACW Write
-- attribute, since such expressions can appear in the expanded
-- code.
if not Comes_From_Source (N)
and then
(PK = N_In
or else PK = N_Attribute_Reference
or else
(PK = N_Type_Conversion
and then Present (Parent (N))
and then Present (Parent (Parent (N)))
and then
Nkind (Parent (Parent (N))) = N_Selected_Component))
then
return;
end if;
Error_Msg_N ("incorrect remote type dereference", N);
end if;
end Validate_Remote_Access_To_Class_Wide_Type;
------------------------------------------
-- Validate_Remote_Type_Type_Conversion --
------------------------------------------
procedure Validate_Remote_Type_Type_Conversion (N : Node_Id) is
S : constant Entity_Id := Etype (N);
E : constant Entity_Id := Etype (Expression (N));
begin
-- This test is required in the case where a conversion appears inside a
-- normal package, it does not necessarily have to be inside an RCI,
-- Remote_Types unit (RM E.2.2(9,12)).
if Is_Remote_Access_To_Subprogram_Type (E)
and then not Is_Remote_Access_To_Subprogram_Type (S)
then
Error_Msg_N
("incorrect conversion of remote operand to local type", N);
return;
elsif not Is_Remote_Access_To_Subprogram_Type (E)
and then Is_Remote_Access_To_Subprogram_Type (S)
then
Error_Msg_N
("incorrect conversion of local operand to remote type", N);
return;
elsif Is_Remote_Access_To_Class_Wide_Type (E)
and then not Is_Remote_Access_To_Class_Wide_Type (S)
then
Error_Msg_N
("incorrect conversion of remote operand to local type", N);
return;
end if;
-- If a local access type is converted into a RACW type, then the
-- current unit has a pointer that may now be exported to another
-- partition.
if Is_Remote_Access_To_Class_Wide_Type (S)
and then not Is_Remote_Access_To_Class_Wide_Type (E)
then
Set_Has_RACW (Current_Sem_Unit);
end if;
end Validate_Remote_Type_Type_Conversion;
-------------------------------
-- Validate_RT_RAT_Component --
-------------------------------
procedure Validate_RT_RAT_Component (N : Node_Id) is
Spec : constant Node_Id := Specification (N);
Name_U : constant Entity_Id := Defining_Entity (Spec);
Typ : Entity_Id;
First_Priv_Ent : constant Entity_Id := First_Private_Entity (Name_U);
In_Visible_Part : Boolean := True;
begin
if not Is_Remote_Types (Name_U) then
return;
end if;
Typ := First_Entity (Name_U);
while Present (Typ) loop
if In_Visible_Part and then Typ = First_Priv_Ent then
In_Visible_Part := False;
end if;
if Comes_From_Source (Typ)
and then Is_Type (Typ)
and then (In_Visible_Part or else Has_Private_Declaration (Typ))
then
if Missing_Read_Write_Attributes (Typ) then
if Is_Non_Remote_Access_Type (Typ) then
Error_Msg_N
("non-remote access type without user-defined Read " &
"and Write attributes", Typ);
else
Error_Msg_N
("record type containing a component of a " &
"non-remote access", Typ);
Error_Msg_N
("\type without Read and Write attributes " &
"('R'M E.2.2(8))", Typ);
end if;
end if;
end if;
Next_Entity (Typ);
end loop;
end Validate_RT_RAT_Component;
-----------------------------------------
-- Validate_SP_Access_Object_Type_Decl --
-----------------------------------------
procedure Validate_SP_Access_Object_Type_Decl (T : Entity_Id) is
Direct_Designated_Type : Entity_Id;
function Has_Entry_Declarations (E : Entity_Id) return Boolean;
-- Return true if the protected type designated by T has
-- entry declarations.
----------------------------
-- Has_Entry_Declarations --
----------------------------
function Has_Entry_Declarations (E : Entity_Id) return Boolean is
Ety : Entity_Id;
begin
if Nkind (Parent (E)) = N_Protected_Type_Declaration then
Ety := First_Entity (E);
while Present (Ety) loop
if Ekind (Ety) = E_Entry then
return True;
end if;
Next_Entity (Ety);
end loop;
end if;
return False;
end Has_Entry_Declarations;
-- Start of processing for Validate_SP_Access_Object_Type_Decl
begin
-- We are called from Sem_Ch3.Analyze_Type_Declaration, and the
-- Nkind of the given entity is N_Access_To_Object_Definition.
if not Comes_From_Source (T)
or else not In_Shared_Passive_Unit
or else In_Subprogram_Task_Protected_Unit
then
return;
end if;
-- Check Shared Passive unit. It should not contain the declaration
-- of an access-to-object type whose designated type is a class-wide
-- type, task type or protected type with entry (RM E.2.1(7)).
Direct_Designated_Type := Designated_Type (T);
if Ekind (Direct_Designated_Type) = E_Class_Wide_Type then
Error_Msg_N
("invalid access-to-class-wide type in shared passive unit", T);
return;
elsif Ekind (Direct_Designated_Type) in Task_Kind then
Error_Msg_N
("invalid access-to-task type in shared passive unit", T);
return;
elsif Ekind (Direct_Designated_Type) in Protected_Kind
and then Has_Entry_Declarations (Direct_Designated_Type)
then
Error_Msg_N
("invalid access-to-protected type in shared passive unit", T);
return;
end if;
end Validate_SP_Access_Object_Type_Decl;
---------------------------------
-- Validate_Static_Object_Name --
---------------------------------
procedure Validate_Static_Object_Name (N : Node_Id) is
E : Entity_Id;
function Is_Primary (N : Node_Id) return Boolean;
-- Determine whether node is syntactically a primary in an expression
----------------
-- Is_Primary --
----------------
function Is_Primary (N : Node_Id) return Boolean is
K : constant Node_Kind := Nkind (Parent (N));
begin
case K is
when N_Op | N_In | N_Not_In =>
return True;
when N_Aggregate
| N_Component_Association
| N_Index_Or_Discriminant_Constraint =>
return True;
when N_Attribute_Reference =>
return Attribute_Name (Parent (N)) /= Name_Address
and then Attribute_Name (Parent (N)) /= Name_Access
and then Attribute_Name (Parent (N)) /= Name_Unchecked_Access
and then
Attribute_Name (Parent (N)) /= Name_Unrestricted_Access;
when N_Indexed_Component =>
return (N /= Prefix (Parent (N))
or else Is_Primary (Parent (N)));
when N_Qualified_Expression | N_Type_Conversion =>
return Is_Primary (Parent (N));
when N_Assignment_Statement | N_Object_Declaration =>
return (N = Expression (Parent (N)));
when N_Selected_Component =>
return Is_Primary (Parent (N));
when others =>
return False;
end case;
end Is_Primary;
-- Start of processing for Validate_Static_Object_Name
begin
if not In_Preelaborated_Unit
or else not Comes_From_Source (N)
or else In_Subprogram_Or_Concurrent_Unit
or else Ekind (Current_Scope) = E_Block
then
return;
-- Filter out cases where primary is default in a component declaration,
-- discriminant specification, or actual in a record type initialization
-- call.
-- Initialization call of internal types
elsif Nkind (Parent (N)) = N_Procedure_Call_Statement then
if Present (Parent (Parent (N)))
and then Nkind (Parent (Parent (N))) = N_Freeze_Entity
then
return;
end if;
if Nkind (Name (Parent (N))) = N_Identifier
and then not Comes_From_Source (Entity (Name (Parent (N))))
then
return;
end if;
end if;
-- Error if the name is a primary in an expression. The parent must not
-- be an operator, or a selected component or an indexed component that
-- is itself a primary. Entities that are actuals do not need to be
-- checked, because the call itself will be diagnosed.
if Is_Primary (N)
and then (not Inside_A_Generic
or else Present (Enclosing_Generic_Body (N)))
then
if Ekind (Entity (N)) = E_Variable then
Flag_Non_Static_Expr
("non-static object name in preelaborated unit", N);
-- We take the view that a constant defined in another preelaborated
-- unit is preelaborable, even though it may have a private type and
-- thus appear non-static in a client. This must be the intent of
-- the language, but currently is an RM gap ???
elsif Ekind (Entity (N)) = E_Constant
and then not Is_Static_Expression (N)
then
E := Entity (N);
if Is_Internal_File_Name (Unit_File_Name (Get_Source_Unit (N)))
and then
Enclosing_Lib_Unit_Node (N) /= Enclosing_Lib_Unit_Node (E)
and then (Is_Preelaborated (Scope (E))
or else Is_Pure (Scope (E))
or else (Present (Renamed_Object (E))
and then
Is_Entity_Name (Renamed_Object (E))
and then
(Is_Preelaborated
(Scope (Renamed_Object (E)))
or else
Is_Pure (Scope
(Renamed_Object (E))))))
then
null;
-- This is the error case
else
-- In GNAT mode, this is just a warning, to allow it to be
-- judiciously turned off. Otherwise it is a real error.
if GNAT_Mode then
Error_Msg_N
("?non-static constant in preelaborated unit", N);
else
Flag_Non_Static_Expr
("non-static constant in preelaborated unit", N);
end if;
end if;
end if;
end if;
end Validate_Static_Object_Name;
end Sem_Cat;