blob: e3075f7e385acaa0dd05ebe53124b228836e96df [file] [log] [blame]
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ D I S T --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2021, 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 Casing; use Casing;
with Einfo; use Einfo;
with Einfo.Entities; use Einfo.Entities;
with Einfo.Utils; use Einfo.Utils;
with Errout; use Errout;
with Exp_Dist; use Exp_Dist;
with Exp_Tss; use Exp_Tss;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Namet; use Namet;
with Opt; use Opt;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Disp; use Sem_Disp;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinfo.Utils; use Sinfo.Utils;
with Stand; use Stand;
with Stringt; use Stringt;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Sem_Dist is
-----------------------
-- Local Subprograms --
-----------------------
procedure RAS_E_Dereference (Pref : Node_Id);
-- Handles explicit dereference of Remote Access to Subprograms
function Full_Qualified_Name (E : Entity_Id) return String_Id;
-- returns the full qualified name of the entity in lower case
-------------------------
-- Add_Stub_Constructs --
-------------------------
procedure Add_Stub_Constructs (N : Node_Id) is
U : constant Node_Id := Unit (N);
Spec : Entity_Id := Empty;
Exp : Node_Id := U;
-- Unit that will be expanded
begin
pragma Assert (Distribution_Stub_Mode /= No_Stubs);
if Nkind (U) = N_Package_Declaration then
Spec := Defining_Entity (Specification (U));
elsif Nkind (U) = N_Package_Body then
Spec := Corresponding_Spec (U);
else pragma Assert (Nkind (U) = N_Package_Instantiation);
Exp := Instance_Spec (U);
Spec := Defining_Entity (Specification (Exp));
end if;
pragma Assert (Is_Shared_Passive (Spec)
or else Is_Remote_Call_Interface (Spec));
if Distribution_Stub_Mode = Generate_Caller_Stub_Body then
if Is_Shared_Passive (Spec) then
null;
elsif Nkind (U) = N_Package_Body then
Error_Msg_N
("Specification file expected from command line", U);
else
Expand_Calling_Stubs_Bodies (Exp);
end if;
else
if Is_Shared_Passive (Spec) then
Build_Passive_Partition_Stub (Exp);
else
Expand_Receiving_Stubs_Bodies (Exp);
end if;
end if;
end Add_Stub_Constructs;
---------------------------------------
-- Build_RAS_Primitive_Specification --
---------------------------------------
function Build_RAS_Primitive_Specification
(Subp_Spec : Node_Id;
Remote_Object_Type : Node_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (Subp_Spec);
Primitive_Spec : constant Node_Id :=
Copy_Specification (Loc,
Spec => Subp_Spec,
New_Name => Name_uCall);
Subtype_Mark_For_Self : Node_Id;
begin
if No (Parameter_Specifications (Primitive_Spec)) then
Set_Parameter_Specifications (Primitive_Spec, New_List);
end if;
if Nkind (Remote_Object_Type) in N_Entity then
Subtype_Mark_For_Self :=
New_Occurrence_Of (Remote_Object_Type, Loc);
else
Subtype_Mark_For_Self := Remote_Object_Type;
end if;
Prepend_To (
Parameter_Specifications (Primitive_Spec),
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uS),
Parameter_Type =>
Make_Access_Definition (Loc,
Subtype_Mark =>
Subtype_Mark_For_Self)));
-- Trick later semantic analysis into considering this operation as a
-- primitive (dispatching) operation of tagged type Obj_Type.
Set_Comes_From_Source (
Defining_Unit_Name (Primitive_Spec), True);
return Primitive_Spec;
end Build_RAS_Primitive_Specification;
-------------------------
-- Full_Qualified_Name --
-------------------------
function Full_Qualified_Name (E : Entity_Id) return String_Id is
Ent : Entity_Id := E;
Parent_Name : String_Id := No_String;
begin
-- Deals properly with child units
if Nkind (Ent) = N_Defining_Program_Unit_Name then
Ent := Defining_Identifier (Ent);
end if;
-- Compute recursively the qualification (only "Standard" has no scope)
if Present (Scope (Scope (Ent))) then
Parent_Name := Full_Qualified_Name (Scope (Ent));
end if;
-- Every entity should have a name except some expanded blocks. Do not
-- bother about those.
if Chars (Ent) = No_Name then
return Parent_Name;
end if;
-- Add a period between Name and qualification
if Parent_Name /= No_String then
Start_String (Parent_Name);
Store_String_Char (Get_Char_Code ('.'));
else
Start_String;
end if;
-- Generates the entity name in upper case
Get_Name_String (Chars (Ent));
Set_Casing (All_Lower_Case);
Store_String_Chars (Name_Buffer (1 .. Name_Len));
return End_String;
end Full_Qualified_Name;
------------------
-- Get_PCS_Name --
------------------
function Get_PCS_Name return PCS_Names is
begin
return
Chars (Entity (Expression (Parent (RTE (RE_DSA_Implementation)))));
end Get_PCS_Name;
---------------------
-- Get_PCS_Version --
---------------------
function Get_PCS_Version return Int is
PCS_Version_Entity : Entity_Id;
PCS_Version : Int;
begin
if RTE_Available (RE_PCS_Version) then
PCS_Version_Entity := RTE (RE_PCS_Version);
pragma Assert (Ekind (PCS_Version_Entity) = E_Named_Integer);
PCS_Version :=
UI_To_Int (Expr_Value (Constant_Value (PCS_Version_Entity)));
else
-- Case of System.Partition_Interface.PCS_Version not found:
-- return a null version.
PCS_Version := 0;
end if;
return PCS_Version;
end Get_PCS_Version;
------------------------
-- Is_All_Remote_Call --
------------------------
function Is_All_Remote_Call (N : Node_Id) return Boolean is
Par : Node_Id;
begin
if Nkind (N) in N_Subprogram_Call
and then Nkind (Name (N)) in N_Has_Entity
and then Is_Remote_Call_Interface (Entity (Name (N)))
and then Has_All_Calls_Remote (Scope (Entity (Name (N))))
and then Comes_From_Source (N)
then
Par := Parent (Entity (Name (N)));
while Present (Par)
and then (Nkind (Par) /= N_Package_Specification
or else Is_Wrapper_Package (Defining_Entity (Par)))
loop
Par := Parent (Par);
end loop;
if Present (Par) then
return
not Scope_Within_Or_Same (Current_Scope, Defining_Entity (Par));
else
return False;
end if;
else
return False;
end if;
end Is_All_Remote_Call;
---------------------------------
-- Is_RACW_Stub_Type_Operation --
---------------------------------
function Is_RACW_Stub_Type_Operation (Op : Entity_Id) return Boolean is
Typ : Entity_Id;
begin
case Ekind (Op) is
when E_Function
| E_Procedure
=>
Typ := Find_Dispatching_Type (Op);
return
Present (Typ)
and then Is_RACW_Stub_Type (Typ)
and then not Is_Internal (Op);
when others =>
return False;
end case;
end Is_RACW_Stub_Type_Operation;
---------------------------------
-- Is_Valid_Remote_Object_Type --
---------------------------------
function Is_Valid_Remote_Object_Type (E : Entity_Id) return Boolean is
P : constant Node_Id := Parent (E);
begin
pragma Assert (Is_Tagged_Type (E));
-- Simple case: a limited private type
if Nkind (P) = N_Private_Type_Declaration
and then Is_Limited_Record (E)
then
return True;
-- AI05-0060 (Binding Interpretation): A limited interface is a legal
-- ancestor for the designated type of an RACW type.
elsif Is_Limited_Record (E) and then Is_Limited_Interface (E) then
return True;
-- A generic tagged limited type is a valid candidate. Limitedness will
-- be checked again on the actual at instantiation point.
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;
-- A private extension declaration is a valid candidate if its parent
-- type is.
elsif Nkind (P) = N_Private_Extension_Declaration then
return Is_Valid_Remote_Object_Type (Etype (E));
else
return False;
end if;
end Is_Valid_Remote_Object_Type;
------------------------------------
-- Package_Specification_Of_Scope --
------------------------------------
function Package_Specification_Of_Scope (E : Entity_Id) return Node_Id is
N : Node_Id;
begin
N := Parent (E);
while Nkind (N) /= N_Package_Specification loop
N := Parent (N);
end loop;
return N;
end Package_Specification_Of_Scope;
--------------------------
-- Process_Partition_Id --
--------------------------
procedure Process_Partition_Id (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ety : Entity_Id;
Get_Pt_Id : Node_Id;
Get_Pt_Id_Call : Node_Id;
Prefix_String : String_Id;
Typ : constant Entity_Id := Etype (N);
begin
-- In case prefix is not a library unit entity, get the entity
-- of library unit.
Ety := Entity (Prefix (N));
while (Present (Scope (Ety))
and then Scope (Ety) /= Standard_Standard)
and not Is_Child_Unit (Ety)
loop
Ety := Scope (Ety);
end loop;
-- Retrieve the proper function to call
if Is_Remote_Call_Interface (Ety) then
Get_Pt_Id := New_Occurrence_Of
(RTE (RE_Get_Active_Partition_Id), Loc);
elsif Is_Shared_Passive (Ety) then
Get_Pt_Id := New_Occurrence_Of
(RTE (RE_Get_Passive_Partition_Id), Loc);
else
Get_Pt_Id := New_Occurrence_Of
(RTE (RE_Get_Local_Partition_Id), Loc);
end if;
-- Get and store the String_Id corresponding to the name of the
-- library unit whose Partition_Id is needed.
Get_Library_Unit_Name_String (Unit_Declaration_Node (Ety));
Prefix_String := String_From_Name_Buffer;
-- Build the function call which will replace the attribute
if Is_Remote_Call_Interface (Ety) or else Is_Shared_Passive (Ety) then
Get_Pt_Id_Call :=
Make_Function_Call (Loc,
Name => Get_Pt_Id,
Parameter_Associations =>
New_List (Make_String_Literal (Loc, Prefix_String)));
else
Get_Pt_Id_Call := Make_Function_Call (Loc, Get_Pt_Id);
end if;
-- Replace the attribute node by a conversion of the function call
-- to the target type.
Rewrite (N, Convert_To (Typ, Get_Pt_Id_Call));
Analyze_And_Resolve (N, Typ);
end Process_Partition_Id;
----------------------------------
-- Process_Remote_AST_Attribute --
----------------------------------
procedure Process_Remote_AST_Attribute
(N : Node_Id;
New_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Remote_Subp : Entity_Id;
Tick_Access_Conv_Call : Node_Id;
Remote_Subp_Decl : Node_Id;
RS_Pkg_Specif : Node_Id;
RS_Pkg_E : Entity_Id;
RAS_Type : Entity_Id := New_Type;
Async_E : Entity_Id;
All_Calls_Remote_E : Entity_Id;
Attribute_Subp : Entity_Id;
begin
-- Check if we have to expand the access attribute
Remote_Subp := Entity (Prefix (N));
if not Expander_Active or else Get_PCS_Name = Name_No_DSA then
return;
end if;
if Ekind (RAS_Type) /= E_Record_Type then
RAS_Type := Equivalent_Type (RAS_Type);
end if;
Attribute_Subp := TSS (RAS_Type, TSS_RAS_Access);
pragma Assert (Present (Attribute_Subp));
Remote_Subp_Decl := Unit_Declaration_Node (Remote_Subp);
if Nkind (Remote_Subp_Decl) = N_Subprogram_Body then
Remote_Subp := Corresponding_Spec (Remote_Subp_Decl);
Remote_Subp_Decl := Unit_Declaration_Node (Remote_Subp);
end if;
RS_Pkg_Specif := Parent (Remote_Subp_Decl);
RS_Pkg_E := Defining_Entity (RS_Pkg_Specif);
Async_E :=
Boolean_Literals (Ekind (Remote_Subp) = E_Procedure
and then Is_Asynchronous (Remote_Subp));
All_Calls_Remote_E :=
Boolean_Literals (Has_All_Calls_Remote (RS_Pkg_E));
Tick_Access_Conv_Call :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Attribute_Subp, Loc),
Parameter_Associations =>
New_List (
Make_String_Literal (Loc,
Strval => Full_Qualified_Name (RS_Pkg_E)),
Build_Subprogram_Id (Loc, Remote_Subp),
New_Occurrence_Of (Async_E, Loc),
New_Occurrence_Of (All_Calls_Remote_E, Loc)));
Rewrite (N, Tick_Access_Conv_Call);
Analyze_And_Resolve (N, RAS_Type);
end Process_Remote_AST_Attribute;
------------------------------------
-- Process_Remote_AST_Declaration --
------------------------------------
procedure Process_Remote_AST_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
User_Type : constant Node_Id := Defining_Identifier (N);
Scop : constant Entity_Id := Scope (User_Type);
Is_RCI : constant Boolean := Is_Remote_Call_Interface (Scop);
Is_RT : constant Boolean := Is_Remote_Types (Scop);
Type_Def : constant Node_Id := Type_Definition (N);
Parameter : Node_Id;
Is_Degenerate : Boolean;
-- True iff this RAS has an access formal parameter (see
-- Exp_Dist.Add_RAS_Dereference_TSS for details).
Subpkg : constant Entity_Id := Make_Temporary (Loc, 'S');
Subpkg_Decl : Node_Id;
Subpkg_Body : Node_Id;
Vis_Decls : constant List_Id := New_List;
Priv_Decls : constant List_Id := New_List;
Obj_Type : constant Entity_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (User_Type), 'R'));
Full_Obj_Type : constant Entity_Id :=
Make_Defining_Identifier (Loc, Chars (Obj_Type));
RACW_Type : constant Entity_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (User_Type), 'P'));
Fat_Type : constant Entity_Id :=
Make_Defining_Identifier (Loc, Chars (User_Type));
Fat_Type_Decl : Node_Id;
begin
Is_Degenerate := False;
Parameter := First (Parameter_Specifications (Type_Def));
while Present (Parameter) loop
if Nkind (Parameter_Type (Parameter)) = N_Access_Definition then
Error_Msg_N
("formal parameter& has anonymous access type??",
Defining_Identifier (Parameter));
Is_Degenerate := True;
exit;
end if;
Next (Parameter);
end loop;
if Is_Degenerate then
Error_Msg_NE
("remote access-to-subprogram type& can only be null??",
Defining_Identifier (Parameter), User_Type);
-- The only legal value for a RAS with a formal parameter of an
-- anonymous access type is null, because it cannot be subtype-
-- conformant with any legal remote subprogram declaration. In this
-- case, we cannot generate a corresponding primitive operation.
end if;
if Get_PCS_Name = Name_No_DSA then
return;
end if;
-- The tagged private type, primitive operation and RACW type associated
-- with a RAS need to all be declared in a subpackage of the one that
-- contains the RAS declaration, because the primitive of the object
-- type, and the associated primitive of the stub type, need to be
-- dispatching operations of these types, and the profile of the RAS
-- might contain tagged types declared in the same scope.
Append_To (Vis_Decls,
Make_Private_Type_Declaration (Loc,
Defining_Identifier => Obj_Type,
Abstract_Present => True,
Tagged_Present => True,
Limited_Present => True));
Append_To (Priv_Decls,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Full_Obj_Type,
Type_Definition =>
Make_Record_Definition (Loc,
Abstract_Present => True,
Tagged_Present => True,
Limited_Present => True,
Null_Present => True,
Component_List => Empty)));
-- Trick semantic analysis into swapping the public and full view when
-- freezing the public view.
Set_Comes_From_Source (Full_Obj_Type, True);
if not Is_Degenerate then
Append_To (Vis_Decls,
Make_Abstract_Subprogram_Declaration (Loc,
Specification => Build_RAS_Primitive_Specification (
Subp_Spec => Type_Def,
Remote_Object_Type => Obj_Type)));
end if;
Append_To (Vis_Decls,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => RACW_Type,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Subtype_Indication =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Obj_Type, Loc),
Attribute_Name => Name_Class))));
Set_Is_Remote_Call_Interface (RACW_Type, Is_RCI);
Set_Is_Remote_Types (RACW_Type, Is_RT);
Subpkg_Decl :=
Make_Package_Declaration (Loc,
Make_Package_Specification (Loc,
Defining_Unit_Name => Subpkg,
Visible_Declarations => Vis_Decls,
Private_Declarations => Priv_Decls,
End_Label => New_Occurrence_Of (Subpkg, Loc)));
Set_Is_Remote_Call_Interface (Subpkg, Is_RCI);
Set_Is_Remote_Types (Subpkg, Is_RT);
Insert_After_And_Analyze (N, Subpkg_Decl);
-- Generate package body to receive RACW calling stubs
-- Note: Analyze_Declarations has an absolute requirement that the
-- declaration list be non-empty, so provide dummy null statement here.
Subpkg_Body :=
Make_Package_Body (Loc,
Defining_Unit_Name => Make_Defining_Identifier (Loc, Chars (Subpkg)),
Declarations => New_List (Make_Null_Statement (Loc)));
Insert_After_And_Analyze (Subpkg_Decl, Subpkg_Body);
-- Many parts of the analyzer and expander expect
-- that the fat pointer type used to implement remote
-- access to subprogram types be a record.
-- Note: The structure of this type must be kept consistent
-- with the code generated by Remote_AST_Null_Value for the
-- corresponding 'null' expression.
Fat_Type_Decl := Make_Full_Type_Declaration (Loc,
Defining_Identifier => Fat_Type,
Type_Definition =>
Make_Record_Definition (Loc,
Component_List =>
Make_Component_List (Loc,
Component_Items => New_List (
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_Ras),
Component_Definition =>
Make_Component_Definition (Loc,
Aliased_Present => False,
Subtype_Indication =>
New_Occurrence_Of (RACW_Type, Loc)))))));
Set_Equivalent_Type (User_Type, Fat_Type);
-- Set Fat_Type's Etype early so that we can use its
-- Corresponding_Remote_Type attribute, whose presence indicates that
-- this is the record type used to implement a RAS.
Mutate_Ekind (Fat_Type, E_Record_Type);
Set_Corresponding_Remote_Type (Fat_Type, User_Type);
Insert_After_And_Analyze (Subpkg_Body, Fat_Type_Decl);
-- The reason we suppress the initialization procedure is that we know
-- that no initialization is required (even if Initialize_Scalars mode
-- is active), and there are order of elaboration problems if we do try
-- to generate an init proc for this created record type.
Set_Suppress_Initialization (Fat_Type);
if Expander_Active then
Add_RAST_Features (Parent (User_Type));
end if;
end Process_Remote_AST_Declaration;
-----------------------
-- RAS_E_Dereference --
-----------------------
procedure RAS_E_Dereference (Pref : Node_Id) is
Loc : constant Source_Ptr := Sloc (Pref);
Call_Node : Node_Id;
New_Type : constant Entity_Id := Etype (Pref);
Explicit_Deref : constant Node_Id := Parent (Pref);
Deref_Subp_Call : constant Node_Id := Parent (Explicit_Deref);
Deref_Proc : Entity_Id;
Params : List_Id;
begin
if Nkind (Deref_Subp_Call) = N_Procedure_Call_Statement then
Params := Parameter_Associations (Deref_Subp_Call);
if Present (Params) then
Prepend (Pref, Params);
else
Params := New_List (Pref);
end if;
elsif Nkind (Deref_Subp_Call) = N_Indexed_Component then
Params := Expressions (Deref_Subp_Call);
if Present (Params) then
Prepend (Pref, Params);
else
Params := New_List (Pref);
end if;
else
-- Context is not a call
return;
end if;
if not Expander_Active or else Get_PCS_Name = Name_No_DSA then
return;
end if;
Deref_Proc := TSS (New_Type, TSS_RAS_Dereference);
pragma Assert (Present (Deref_Proc));
if Ekind (Deref_Proc) = E_Function then
Call_Node :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Deref_Proc, Loc),
Parameter_Associations => Params);
else
Call_Node :=
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Deref_Proc, Loc),
Parameter_Associations => Params);
end if;
Rewrite (Deref_Subp_Call, Call_Node);
Analyze (Deref_Subp_Call);
end RAS_E_Dereference;
------------------------------
-- Remote_AST_E_Dereference --
------------------------------
function Remote_AST_E_Dereference (P : Node_Id) return Boolean is
ET : constant Entity_Id := Etype (P);
begin
-- Perform the changes only on original dereferences, and only if
-- we are generating code.
if Comes_From_Source (P)
and then Expander_Active
and then Is_Record_Type (ET)
and then (Is_Remote_Call_Interface (ET) or else Is_Remote_Types (ET))
and then Present (Corresponding_Remote_Type (ET))
and then Nkind (Parent (Parent (P))) in
N_Procedure_Call_Statement | N_Indexed_Component
then
RAS_E_Dereference (P);
return True;
else
return False;
end if;
end Remote_AST_E_Dereference;
------------------------------
-- Remote_AST_I_Dereference --
------------------------------
function Remote_AST_I_Dereference (P : Node_Id) return Boolean is
ET : constant Entity_Id := Etype (P);
Deref : Node_Id;
begin
if Comes_From_Source (P)
and then (Is_Remote_Call_Interface (ET)
or else Is_Remote_Types (ET))
and then Present (Corresponding_Remote_Type (ET))
and then Ekind (Entity (P)) /= E_Function
then
Deref :=
Make_Explicit_Dereference (Sloc (P),
Prefix => Relocate_Node (P));
Rewrite (P, Deref);
Set_Etype (P, ET);
RAS_E_Dereference (Prefix (P));
return True;
end if;
return False;
end Remote_AST_I_Dereference;
---------------------------
-- Remote_AST_Null_Value --
---------------------------
function Remote_AST_Null_Value
(N : Node_Id;
Typ : Entity_Id) return Boolean
is
Loc : constant Source_Ptr := Sloc (N);
Target_Type : Entity_Id;
begin
if not Expander_Active or else Get_PCS_Name = Name_No_DSA then
return False;
elsif Ekind (Typ) = E_Access_Subprogram_Type
and then (Is_Remote_Call_Interface (Typ)
or else Is_Remote_Types (Typ))
and then Comes_From_Source (N)
and then Expander_Active
then
-- Any null that comes from source and is of the RAS type must
-- be expanded, except if expansion is not active (nothing
-- gets expanded into the equivalent record type).
Target_Type := Equivalent_Type (Typ);
elsif Ekind (Typ) = E_Record_Type
and then Present (Corresponding_Remote_Type (Typ))
then
-- This is a record type representing a RAS type, this must be
-- expanded.
Target_Type := Typ;
else
-- We do not have to handle this case
return False;
end if;
Rewrite (N,
Make_Aggregate (Loc,
Component_Associations => New_List (
Make_Component_Association (Loc,
Choices => New_List (Make_Identifier (Loc, Name_Ras)),
Expression => Make_Null (Loc)))));
Analyze_And_Resolve (N, Target_Type);
return True;
end Remote_AST_Null_Value;
end Sem_Dist;