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|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C A T --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2017, 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 3, 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 COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- 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_Disp; use Exp_Disp;
with Lib; use Lib;
with Namet; use Namet;
with Nlists; use Nlists;
with Opt; use Opt;
with Sem; use Sem;
with Sem_Attr; use Sem_Attr;
with Sem_Aux; use Sem_Aux;
with Sem_Dist; use Sem_Dist;
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.
function Has_Read_Write_Attributes (E : Entity_Id) return Boolean;
-- Return True if entity has attribute definition clauses for Read and
-- Write attributes that are visible at some place.
function Is_Non_Remote_Access_Type (E : Entity_Id) return Boolean;
-- Returns true if the entity is a type whose full view is a non-remote
-- access type, for the purpose of enforcing E.2.2(8) rules.
function Has_Non_Remote_Access (Typ : Entity_Id) return Boolean;
-- Return true if Typ or the type of any of its subcomponents is a non
-- remote access type and doesn't have user-defined stream attributes.
function No_External_Streaming (E : Entity_Id) return Boolean;
-- Return True if the entity or one of its subcomponents does not support
-- external streaming.
function In_RCI_Declaration return Boolean;
function In_RT_Declaration return Boolean;
-- Determine if current scope is within the declaration of a Remote Call
-- Interface or Remote Types unit, for semantic checking purposes.
function In_Package_Declaration return Boolean;
-- Shared supporting routine for In_RCI_Declaration and In_RT_Declaration
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)
procedure Validate_RACW_Primitive
(Subp : Entity_Id;
RACW : Entity_Id);
-- Check legality of the declaration of primitive Subp of the designated
-- type of the given RACW type.
---------------------------------------
-- 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;
Err : Boolean;
-- 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,
Normal);
function Get_Categorization (E : Entity_Id) return Categorization;
-- Check categorization flags from entity, and return in the form
-- of the lowest value of the Categorization type that applies to E.
------------------------
-- Get_Categorization --
------------------------
function Get_Categorization (E : Entity_Id) return Categorization is
begin
-- Get the lowest categorization that corresponds to E. Note that
-- nothing prevents several (different) categorization pragmas
-- to apply to the same library unit, in which case the unit has
-- all associated categories, so we need to be careful here to
-- check pragmas in proper Categorization order in order to
-- return the lowest applicable value.
-- Ignore Pure specification if set by pragma Pure_Function
if 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;
Unit_Category : Categorization;
With_Category : Categorization;
-- Start of processing for Check_Categorization_Dependencies
begin
-- Intrinsic subprograms are preelaborated, so do not impose any
-- categorization dependencies. Also, ignore categorization
-- dependencies when compilation switch -gnatdu is used.
if Is_Intrinsic_Subprogram (Depended_Entity) or else Debug_Flag_U then
return;
end if;
-- First check 10.2.1 (11/1) rules on preelaborate packages
if Is_Preelaborated (Unit_Entity)
and then not Is_Preelaborated (Depended_Entity)
and then not Is_Pure (Depended_Entity)
then
Err := True;
else
Err := False;
end if;
-- Check categorization rules of RM E.2(5)
Unit_Category := Get_Categorization (Unit_Entity);
With_Category := Get_Categorization (Depended_Entity);
if With_Category > Unit_Category then
-- Special case: Remote_Types and Remote_Call_Interface are allowed
-- to WITH anything in the package body, per (RM E.2(5)).
if (Unit_Category = Remote_Types
or else Unit_Category = Remote_Call_Interface)
and then In_Package_Body (Unit_Entity)
then
null;
-- Special case: Remote_Types and Remote_Call_Interface declarations
-- can depend on a preelaborated unit via a private with_clause, per
-- AI05-0206.
elsif (Unit_Category = Remote_Types
or else
Unit_Category = Remote_Call_Interface)
and then Nkind (N) = N_With_Clause
and then Private_Present (N)
and then Is_Preelaborated (Depended_Entity)
then
null;
-- All other cases, we do have an error
else
Err := True;
end if;
end if;
-- Here if we have an error
if Err then
-- These messages are warnings in GNAT mode or if the -gnateP switch
-- was set. Otherwise these are real errors for real illegalities.
-- The reason we suppress these errors in GNAT mode is that the run-
-- time has several instances of violations of the categorization
-- errors (e.g. Pure units withing Preelaborate units. All these
-- violations are harmless in the cases where we intend them, and
-- we suppress the warnings with Warnings (Off). In cases where we
-- do not intend the violation, warnings are errors in GNAT mode
-- anyway, so we will still get an error.
Error_Msg_Warn :=
Treat_Categorization_Errors_As_Warnings or GNAT_Mode;
-- Don't give error if main unit is not an internal unit, and the
-- unit generating the message is an internal unit. This is the
-- situation in which such messages would be ignored in any case,
-- so it is convenient not to generate them (since it causes
-- annoying interference with debugging).
if Is_Internal_Unit (Current_Sem_Unit)
and then not Is_Internal_Unit (Main_Unit)
then
return;
-- Dependence of Remote_Types or Remote_Call_Interface declaration
-- on a preelaborated unit with a normal with_clause.
elsif (Unit_Category = Remote_Types
or else
Unit_Category = Remote_Call_Interface)
and then Is_Preelaborated (Depended_Entity)
then
Error_Msg_NE
("<<must use private with clause for preelaborated unit& ",
N, Depended_Entity);
-- Subunit case
elsif Is_Subunit then
Error_Msg_NE
("<subunit cannot depend on& " &
"(parent has wrong categorization)", N, Depended_Entity);
-- Normal unit, not subunit
else
Error_Msg_NE
("<<cannot depend on& " &
"(wrong categorization)", N, Depended_Entity);
end if;
-- Add further explanation for Pure/Preelaborate common cases
if Unit_Category = Pure then
Error_Msg_NE
("\<<pure unit cannot depend on non-pure unit",
N, Depended_Entity);
elsif Is_Preelaborated (Unit_Entity)
and then not Is_Preelaborated (Depended_Entity)
and then not Is_Pure (Depended_Entity)
then
Error_Msg_NE
("\<<preelaborated unit cannot depend on "
& "non-preelaborated unit",
N, Depended_Entity);
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_OK_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;
---------------------------
-- Has_Non_Remote_Access --
---------------------------
function Has_Non_Remote_Access (Typ : Entity_Id) return Boolean is
Component : Entity_Id;
Comp_Type : Entity_Id;
U_Typ : constant Entity_Id := Underlying_Type (Typ);
begin
if No (U_Typ) then
return False;
elsif Has_Read_Write_Attributes (Typ)
or else Has_Read_Write_Attributes (U_Typ)
then
return False;
elsif Is_Non_Remote_Access_Type (U_Typ) then
return True;
end if;
if Is_Record_Type (U_Typ) then
Component := First_Entity (U_Typ);
while Present (Component) loop
if not Is_Tag (Component) then
Comp_Type := Etype (Component);
if Has_Non_Remote_Access (Comp_Type) then
return True;
end if;
end if;
Next_Entity (Component);
end loop;
elsif Is_Array_Type (U_Typ) then
return Has_Non_Remote_Access (Component_Type (U_Typ));
end if;
return False;
end Has_Non_Remote_Access;
-------------------------------
-- Has_Read_Write_Attributes --
-------------------------------
function Has_Read_Write_Attributes (E : Entity_Id) return Boolean is
begin
return True
and then Has_Stream_Attribute_Definition
(E, TSS_Stream_Read, At_Any_Place => True)
and then Has_Stream_Attribute_Definition
(E, TSS_Stream_Write, At_Any_Place => True);
end Has_Read_Write_Attributes;
-------------------------------------
-- Has_Stream_Attribute_Definition --
-------------------------------------
function Has_Stream_Attribute_Definition
(Typ : Entity_Id;
Nam : TSS_Name_Type;
At_Any_Place : Boolean := False) return Boolean
is
Rep_Item : Node_Id;
Real_Rep : Node_Id;
-- The stream operation may be specified by an attribute definition
-- clause in the source, or by an aspect that generates such an
-- attribute definition. For an aspect, the generated attribute
-- definition may be placed at the freeze point of the full view of
-- the type, but the aspect specification makes the operation visible
-- to a client wherever the partial view is visible.
begin
-- We start from the declaration node and then loop until the end of
-- the list until we find the requested attribute definition clause.
-- In Ada 2005 mode, clauses are ignored if they are not currently
-- visible (this is tested using the corresponding Entity, which is
-- inserted by the expander at the point where the clause occurs),
-- unless At_Any_Place is true.
Rep_Item := First_Rep_Item (Typ);
while Present (Rep_Item) loop
Real_Rep := Rep_Item;
-- If the representation item is an aspect specification, retrieve
-- the corresponding pragma or attribute definition.
if Nkind (Rep_Item) = N_Aspect_Specification then
Real_Rep := Aspect_Rep_Item (Rep_Item);
end if;
if Nkind (Real_Rep) = N_Attribute_Definition_Clause then
case Chars (Real_Rep) is
when Name_Read =>
exit when Nam = TSS_Stream_Read;
when Name_Write =>
exit when Nam = TSS_Stream_Write;
when Name_Input =>
exit when Nam = TSS_Stream_Input;
when Name_Output =>
exit when Nam = TSS_Stream_Output;
when others =>
null;
end case;
end if;
Next_Rep_Item (Rep_Item);
end loop;
-- If not found, and the type is derived from a private view, check
-- for a stream attribute inherited from parent. Any specified stream
-- attributes will be attached to the derived type's underlying type
-- rather the derived type entity itself (which is itself private).
if No (Rep_Item)
and then Is_Private_Type (Typ)
and then Is_Derived_Type (Typ)
and then Present (Full_View (Typ))
then
return Has_Stream_Attribute_Definition
(Underlying_Type (Typ), Nam, At_Any_Place);
-- Otherwise, if At_Any_Place is true, return True if the attribute is
-- available at any place; if it is false, return True only if the
-- attribute is currently visible.
else
return Present (Rep_Item)
and then (Ada_Version < Ada_2005
or else At_Any_Place
or else not Is_Hidden (Entity (Rep_Item)));
end if;
end Has_Stream_Attribute_Definition;
----------------------------
-- In_Package_Declaration --
----------------------------
function In_Package_Declaration return Boolean is
Unit_Kind : constant Node_Kind :=
Nkind (Unit (Cunit (Current_Sem_Unit)));
begin
-- There are no restrictions on the body of an RCI or RT unit
return Is_Package_Or_Generic_Package (Current_Scope)
and then Unit_Kind /= N_Package_Body
and then not In_Package_Body (Current_Scope)
and then not In_Instance;
end In_Package_Declaration;
---------------------------
-- In_Preelaborated_Unit --
---------------------------
function In_Preelaborated_Unit return Boolean is
Unit_Entity : Entity_Id := Current_Scope;
Unit_Kind : constant Node_Kind :=
Nkind (Unit (Cunit (Current_Sem_Unit)));
begin
-- If evaluating actuals for a child unit instantiation, then ignore
-- the preelaboration status of the parent; use the child instead.
if Is_Compilation_Unit (Unit_Entity)
and then Unit_Kind in N_Generic_Instantiation
and then not In_Same_Source_Unit (Unit_Entity,
Cunit (Current_Sem_Unit))
then
Unit_Entity := Cunit_Entity (Current_Sem_Unit);
end if;
-- There are no constraints on the 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 return Boolean is
begin
return Is_Remote_Call_Interface (Current_Scope)
and then In_Package_Declaration;
end In_RCI_Declaration;
-----------------------
-- In_RT_Declaration --
-----------------------
function In_RT_Declaration return Boolean is
begin
return Is_Remote_Types (Current_Scope) and then In_Package_Declaration;
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_Or_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
U_E : constant Entity_Id := Underlying_Type (Base_Type (E));
-- Use full view of base type to handle subtypes properly.
begin
if No (U_E) then
-- This case arises for the case of a generic formal type, in which
-- case E.2.2(8) rules will be enforced at instantiation time.
return False;
end if;
return Is_Access_Type (U_E)
and then not Is_Remote_Access_To_Class_Wide_Type (U_E)
and then not Is_Remote_Access_To_Subprogram_Type (U_E);
end Is_Non_Remote_Access_Type;
---------------------------
-- No_External_Streaming --
---------------------------
function No_External_Streaming (E : Entity_Id) return Boolean is
U_E : constant Entity_Id := Underlying_Type (E);
begin
if No (U_E) then
return False;
elsif Has_Read_Write_Attributes (E) then
-- Note: availability of stream attributes is tested on E, not U_E.
-- There may be stream attributes defined on U_E that are not visible
-- at the place where support of external streaming is tested.
return False;
elsif Has_Non_Remote_Access (U_E) then
return True;
end if;
return Is_Limited_Type (E);
end No_External_Streaming;
-------------------------------------
-- 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.
-----------------
-- Set_Parents --
-----------------
procedure Set_Parents (Visibility : Boolean) is
Par : Entity_Id;
begin
Par := Scope (S);
while Present (Par) and then Par /= Standard_Standard loop
Set_Is_Immediately_Visible (Par, Visibility);
Par := Scope (Par);
end loop;
end Set_Parents;
-- Start of processing for Set_Categorization_From_Pragmas
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;
begin
if Is_Child_Unit (S) and then Is_Generic_Instance (S) then
Set_Parents (True);
end if;
PN := First (Pragmas_After (Aux_Decls_Node (P)));
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 (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
-- Do not modify the purity of an internally generated entity if it has
-- been explicitly marked as pure for optimization purposes.
if not Has_Pragma_Pure_Function (E) then
Set_Is_Pure
(E, Is_Pure (Scop) and then Is_Library_Level_Entity (E));
end if;
if not Is_Remote_Call_Interface (E) then
if Ekind (E) in Subprogram_Kind then
Declaration := Unit_Declaration_Node (E);
if Nkind_In (Declaration, N_Subprogram_Body,
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)
and then not (In_Private_Part (Scop)
or else In_Package_Body (Scop)));
end Set_Categorization_From_Scope;
------------------------------
-- Static_Discriminant_Expr --
------------------------------
-- We need to accommodate 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_OK_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_2005
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: declaration of an
-- access-to-object type is illegal unless it is a general access
-- type that designates a class-wide limited private type.
-- Note that constraints on the primitive subprograms of the
-- designated tagged type are not enforced here but in
-- Validate_RACW_Primitives, which is done separately because the
-- designated type might not be frozen (and therefore its
-- primitive operations might not be completely known) at the
-- point of the RACW declaration.
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
-- If the type is private, it must have the Ada 2005 pragma
-- Has_Preelaborable_Initialization.
-- The check is omitted within predefined units. This is probably
-- obsolete code to fix the Ada 95 weakness in this area ???
if Is_Private_Type (T)
and then not Has_Pragma_Preelab_Init (T)
and then not In_Internal_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_In (N, N_Package_Body, 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)
-- Skip if error already posted on the WITH clause (in
-- which case the Name attribute may be invalid). In
-- particular, this fixes the problem of hanging in the
-- presence of a WITH clause on a child that is an
-- illegal generic instantiation.
or else Error_Posted (Item))
and then
not (Try_Semantics
-- Skip processing malformed trees
and then Nkind (Name (Item)) not in N_Has_Entity)
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 satisfy 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
-- Don't need this check in Ada 2005 mode, where this is all taken
-- care of by the mechanism for Preelaborable Initialization.
if Ada_Version >= Ada_2005 then
return;
end if;
-- 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 In_Internal_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 the initialization does not come from source and is an
-- aggregate, it is a static initialization that replaces an
-- implicit call, and must be treated as such.
if Present (E)
and then (Comes_From_Source (E) or else Nkind (E) /= N_Aggregate)
then
null;
elsif Is_Imported (Id) then
null;
else
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;
begin
Comp_Type := Component_Type (Ent);
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;
-- Check for invalid use of private object. Note that Ada 2005
-- AI-161 modifies the rules for Ada 2005, including the use of
-- the new pragma Preelaborable_Initialization.
if Is_Private_Type (Ent)
or else Depends_On_Private (Ent)
then
-- Case where type has preelaborable initialization which
-- means that a pragma Preelaborable_Initialization was
-- given for the private type.
if Relaxed_RM_Semantics then
-- In relaxed mode, do not issue these messages, this
-- is basically similar to the GNAT_Mode test below.
null;
elsif Has_Preelaborable_Initialization (Ent) then
-- But for the predefined units, we will ignore this
-- status unless we are in Ada 2005 mode since we want
-- Ada 95 compatible behavior, in which the entities
-- marked with this pragma in the predefined library are
-- not treated specially.
if Ada_Version < Ada_2005 then
Error_Msg_N
("private object not allowed in preelaborated unit",
N);
Error_Msg_N ("\(would be legal in Ada 2005 mode)", N);
end if;
-- Type does not have preelaborable initialization
else
-- We allow this when compiling in GNAT mode to make life
-- easier for some cases where it would otherwise be hard
-- to be exactly valid Ada.
if not GNAT_Mode then
Error_Msg_N
("private object not allowed in preelaborated unit",
N);
-- Add a message if it would help to provide a pragma
-- Preelaborable_Initialization on the type of the
-- object (which would make it legal in Ada 2005).
-- If the type has no full view (generic type, or
-- previous error), the warning does not apply.
if Is_Private_Type (Ent)
and then Present (Full_View (Ent))
and then
Has_Preelaborable_Initialization (Full_View (Ent))
then
Error_Msg_Sloc := Sloc (Ent);
if Ada_Version >= Ada_2005 then
Error_Msg_NE
("\would be legal if pragma Preelaborable_" &
"Initialization given for & #", N, Ent);
else
Error_Msg_NE
("\would be legal in Ada 2005 if pragma " &
"Preelaborable_Initialization given for & #",
N, Ent);
end if;
end if;
end if;
end if;
-- 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);
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 discriminants not allowed in preelaborated unit.
-- Objects of a controlled type with a user-defined Initialize
-- are forbidden as well.
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;
-- For controlled type or type with controlled component, check
-- preelaboration flag, as there may be a non-null Initialize
-- primitive. For language versions earlier than Ada 2005,
-- there is no notion of preelaborable initialization, and
-- Validate_Controlled_Object is used to enforce rules for
-- controlled objects.
if (Is_Controlled (ET) or else Has_Controlled_Component (ET))
and then Ada_Version >= Ada_2005
and then not Has_Preelaborable_Initialization (ET)
then
Error_Msg_NE
("controlled type& does not have"
& " preelaborable initialization", N, ET);
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);
elsif not In_Private_Part (Id) then
-- The visible part of an RCI library unit must not contain the
-- declaration of a variable (RM E.1.3(9)).
if In_RCI_Declaration then
Error_Msg_N ("visible variable not allowed in 'R'C'I 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
("visible variable not allowed in remote types unit", N);
end if;
end if;
end Validate_Object_Declaration;
-----------------------------
-- Validate_RACW_Primitive --
-----------------------------
procedure Validate_RACW_Primitive
(Subp : Entity_Id;
RACW : Entity_Id)
is
procedure Illegal_Remote_Subp (Msg : String; N : Node_Id);
-- Diagnose illegality on N. If RACW is present, report the error on it
-- rather than on N.
-------------------------
-- Illegal_Remote_Subp --
-------------------------
procedure Illegal_Remote_Subp (Msg : String; N : Node_Id) is
begin
if Present (RACW) then
if not Error_Posted (RACW) then
Error_Msg_N
("illegal remote access to class-wide type&", RACW);
end if;
Error_Msg_Sloc := Sloc (N);
Error_Msg_NE ("\\" & Msg & " in primitive& #", RACW, Subp);
else
Error_Msg_NE (Msg & " in remote subprogram&", N, Subp);
end if;
end Illegal_Remote_Subp;
Rtyp : Entity_Id;
Param : Node_Id;
Param_Spec : Node_Id;
Param_Type : Entity_Id;
-- Start of processing for Validate_RACW_Primitive
begin
-- Check return type
if Ekind (Subp) = E_Function then
Rtyp := Etype (Subp);
-- AI05-0101 (Binding Interpretation): The result type of a remote
-- function must either support external streaming or be a
-- controlling access result type.
if Has_Controlling_Result (Subp) then
null;
elsif Ekind (Rtyp) = E_Anonymous_Access_Type then
Illegal_Remote_Subp ("anonymous access result", Rtyp);
elsif Is_Limited_Type (Rtyp) then
if No (TSS (Rtyp, TSS_Stream_Read))
or else
No (TSS (Rtyp, TSS_Stream_Write))
then
Illegal_Remote_Subp
("limited return type must have Read and Write attributes",
Parent (Subp));
Explain_Limited_Type (Rtyp, Parent (Subp));
end if;
-- Check that the return type supports external streaming
elsif No_External_Streaming (Rtyp)
and then not Error_Posted (Rtyp)
then
Illegal_Remote_Subp ("return type containing non-remote access "
& "must have Read and Write attributes",
Parent (Subp));
end if;
end if;
Param := First_Formal (Subp);
while Present (Param) loop
-- Now find out if this parameter is a controlling parameter
Param_Spec := Parent (Param);
Param_Type := Etype (Param);
if Is_Controlling_Formal (Param) then
-- It is a controlling parameter, so specific checks below do not
-- apply.
null;
elsif Ekind_In (Param_Type, E_Anonymous_Access_Type,
E_Anonymous_Access_Subprogram_Type)
then
-- From RM E.2.2(14), no anonymous access parameter other than
-- controlling ones may be used (because an anonymous access
-- type never supports external streaming).
Illegal_Remote_Subp
("non-controlling access parameter", Param_Spec);
elsif No_External_Streaming (Param_Type)
and then not Error_Posted (Param_Type)
then
Illegal_Remote_Subp ("formal parameter in remote subprogram must "
& "support external streaming", Param_Spec);
end if;
-- Check next parameter in this subprogram
Next_Formal (Param);
end loop;
end Validate_RACW_Primitive;
------------------------------
-- Validate_RACW_Primitives --
------------------------------
procedure Validate_RACW_Primitives (T : Entity_Id) is
Desig_Type : Entity_Id;
Primitive_Subprograms : Elist_Id;
Subprogram_Elmt : Elmt_Id;
Subprogram : Entity_Id;
begin
Desig_Type := Etype (Designated_Type (T));
-- No action needed for concurrent types
if Is_Concurrent_Type (Desig_Type) then
return;
end if;
Primitive_Subprograms := Primitive_Operations (Desig_Type);
Subprogram_Elmt := First_Elmt (Primitive_Subprograms);
while Subprogram_Elmt /= No_Elmt loop
Subprogram := Node (Subprogram_Elmt);
if Is_Predefined_Dispatching_Operation (Subprogram)
or else Is_Hidden (Subprogram)
then
goto Next_Subprogram;
end if;
Validate_RACW_Primitive (Subp => Subprogram, RACW => T);
<<Next_Subprogram>>
Next_Elmt (Subprogram_Elmt);
end loop;
end Validate_RACW_Primitives;
-------------------------------
-- 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_In (E, E_Generic_Function,
E_Generic_Package,
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 : constant Entity_Id := Defining_Entity (N);
Param_Spec : Node_Id;
Param_Type : Entity_Id;
Error_Node : Node_Id := N;
begin
-- This procedure enforces rules on subprogram and access to subprogram
-- declarations in RCI units. These rules do not apply to expander
-- generated routines, which are not remote subprograms. It is called:
-- 1. from Analyze_Subprogram_Declaration.
-- 2. from Validate_Object_Declaration (access to subprogram).
if not (Comes_From_Source (N)
and then In_RCI_Declaration
and then not In_Private_Part (Scope (Id)))
then
return;
end if;
if K = N_Subprogram_Declaration then
Profile := Parameter_Specifications (Specification (N));
else
pragma Assert (K = N_Object_Declaration);
-- The above assertion is dubious, the visible declarations of an
-- RCI unit never contain an object declaration, this should be an
-- ACCESS-to-object declaration???
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));
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 (Id) then
Error_Msg_N
("subprogram in 'R'C'I unit cannot have access parameter",
Error_Node);
end if;
-- For a limited private type parameter, we check only the private
-- declaration and ignore full type declaration, unless this is
-- the only declaration for the type, e.g., as a limited record.
elsif No_External_Streaming (Param_Type) then
if K = N_Subprogram_Declaration then
Error_Node := Param_Spec;
end if;
Error_Msg_NE
("formal of remote subprogram& "
& "must support external streaming",
Error_Node, Id);
if Is_Limited_Type (Param_Type) then
Explain_Limited_Type (Param_Type, Error_Node);
end if;
end if;
Next (Param_Spec);
end loop;
end if;
if Ekind (Id) = E_Function
and then Ekind (Etype (Id)) = E_Anonymous_Access_Type
and then Comes_From_Source (Id)
then
Error_Msg_N
("function in 'R'C'I unit cannot have access result",
Error_Node);
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;
begin
-- We are called from Analyze_Full_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 and then not In_RT_Declaration)
then
return;
end if;
-- An access definition in the private part of a package is not a
-- remote access type. Restrictions related to external streaming
-- support for non-remote access types are enforced elsewhere. Note
-- that In_Private_Part is never set on type entities: check flag
-- on enclosing scope.
if 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 or subtype.
-- There are also constraints on the primitive subprograms of the
-- class-wide type (RM E.2.2(14), see Validate_RACW_Primitives).
if Ekind (T) /= E_General_Access_Type
or else not Is_Class_Wide_Type (Designated_Type (T))
then
if In_RCI_Declaration then
Error_Msg_N
("error in access type in Remote_Call_Interface unit", T);
else
Error_Msg_N
("error in access type in Remote_Types unit", T);
end if;
Error_Msg_N ("\must be general access to class-wide type", T);
return;
end if;
Direct_Designated_Type := Designated_Type (T);
Desig_Type := Etype (Direct_Designated_Type);
-- Why is this check not in Validate_Remote_Access_To_Class_Wide_Type???
if not Is_Valid_Remote_Object_Type (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", T);
return;
end if;
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 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 several 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_ch4 Analyze_Explicit_Dereference
-- 4. 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;
-- 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. Explicit dereferences not coming from source are
-- exempted from this checking because the expander produces them in
-- some cases (such as for tag checks on dispatching calls with multiple
-- controlling operands). However we do check in the case of an implicit
-- dereference that is expanded to an explicit dereference (hence the
-- test of whether Original_Node (N) comes from source).
elsif K = N_Explicit_Dereference
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.
if Is_Actual_Parameter (N) 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. The same can
-- apply in the case of dereference that is the prefix of a selected
-- component, which can be a call given in prefixed form.
if (Is_Actual_Parameter (N) or else PK = N_Selected_Component)
and then not Analyzed (N)
then
return;
end if;
-- We must allow expanded code to generate a reference to the tag of
-- the designated object (may be either the actual tag, or the stub
-- tag in the case of a remote object).
if PK = N_Selected_Component
and then Is_Tag (Entity (Selector_Name (Parent (N))))
then
return;
end if;
Error_Msg_N
("invalid dereference of a remote access-to-class-wide value", 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;
U_Typ : Entity_Id;
First_Priv_Ent : constant Entity_Id := First_Private_Entity (Name_U);
function Stream_Attributes_Available (Typ : Entity_Id) return Boolean;
-- True if any stream attribute is available for Typ
---------------------------------
-- Stream_Attributes_Available --
---------------------------------
function Stream_Attributes_Available (Typ : Entity_Id) return Boolean
is
begin
return Stream_Attribute_Available (Typ, TSS_Stream_Read)
or else
Stream_Attribute_Available (Typ, TSS_Stream_Write)
or else
Stream_Attribute_Available (Typ, TSS_Stream_Input)
or else
Stream_Attribute_Available (Typ, TSS_Stream_Output);
end Stream_Attributes_Available;
-- Start of processing for Validate_RT_RAT_Component
begin
if not Is_Remote_Types (Name_U) then
return;
end if;
Typ := First_Entity (Name_U);
while Present (Typ) and then Typ /= First_Priv_Ent loop
U_Typ := Underlying_Type (Base_Type (Typ));
if No (U_Typ) then
U_Typ := Typ;
end if;
if Comes_From_Source (Typ) and then Is_Type (Typ)
and then Ekind (Typ) /= E_Incomplete_Type
then
-- Check that the type can be meaningfully transmitted to another
-- partition (E.2.2(8)).
if (Ada_Version < Ada_2005 and then Has_Non_Remote_Access (U_Typ))
or else (Stream_Attributes_Available (Typ)
and then No_External_Streaming (U_Typ))
then
if Is_Non_Remote_Access_Type (Typ) then
Error_Msg_N ("error in non-remote access type", U_Typ);
else
Error_Msg_N
("error in record type containing a component of a " &
"non-remote access type", U_Typ);
end if;
if Ada_Version >= Ada_2005 then
Error_Msg_N
("\must have visible Read and Write attribute " &
"definition clauses (RM E.2.2(8))", U_Typ);
else
Error_Msg_N
("\must have Read and Write attribute " &
"definition clauses (RM E.2.2(8))", U_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_Full_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;
Val : Node_Id;
function Is_Primary (N : Node_Id) return Boolean;
-- Determine whether node is syntactically a primary in an expression
-- This function should probably be somewhere else ???
--
-- Also it does not do what it says, e.g if N is a binary operator
-- whose parent is a binary operator, Is_Primary returns True ???
----------------
-- Is_Primary --
----------------
function Is_Primary (N : Node_Id) return Boolean is
K : constant Node_Kind := Nkind (Parent (N));
begin
case K is
when N_Aggregate
| N_Component_Association
| N_Index_Or_Discriminant_Constraint
| N_Membership_Test
| N_Op
=>
return True;
when N_Attribute_Reference =>
declare
Attr : constant Name_Id := Attribute_Name (Parent (N));
begin
return Attr /= Name_Address
and then Attr /= Name_Access
and then Attr /= Name_Unchecked_Access
and then Attr /= Name_Unrestricted_Access;
end;
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. Entities in a
-- generic unit or within a preanalyzed expression are not checked:
-- only their use in executable code matters.
if Is_Primary (N)
and then (not Inside_A_Generic
or else Present (Enclosing_Generic_Body (N)))
and then not In_Spec_Expression
then
if Ekind (Entity (N)) = E_Variable
or else Ekind (Entity (N)) in Formal_Object_Kind
then
Flag_Non_Static_Expr
("non-static object name in preelaborated unit", N);
-- Give an error for a reference to a nonstatic constant, unless the
-- constant is in another GNAT library unit that is preelaborable.
elsif Ekind (Entity (N)) = E_Constant
and then not Is_Static_Expression (N)
then
E := Entity (N);
Val := Constant_Value (E);
if In_Internal_Unit (N)
and then
Enclosing_Comp_Unit_Node (N) /= Enclosing_Comp_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;
-- If the value of the constant is a local variable that renames
-- an aggregate, this is in itself legal. The aggregate may be
-- expanded into a loop, but this does not affect preelaborability
-- in itself. If some aggregate components are non-static, that is
-- to say if they involve non static primaries, they will be
-- flagged when analyzed.
elsif Present (Val)
and then Is_Entity_Name (Val)
and then Is_Array_Type (Etype (Val))
and then not Comes_From_Source (Val)
and then Nkind (Original_Node (Val)) = N_Aggregate
then
null;
-- This is the error case
else
-- In GNAT mode or Relaxed RM Semantic mode, this is just a
-- warning, to allow it to be judiciously turned off.
-- Otherwise it is a real error.
if GNAT_Mode or Relaxed_RM_Semantics 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;
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