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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ C H 7 --
-- --
-- B o d y --
-- --
-- $Revision$
-- --
-- Copyright (C) 1992-2001, 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, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
-- This package contains virtually all expansion mechanisms related to
-- - controlled types
-- - transient scopes
with Atree; use Atree;
with Debug; use Debug;
with Einfo; use Einfo;
with Exp_Ch9; use Exp_Ch9;
with Exp_Ch11; use Exp_Ch11;
with Exp_Dbug; use Exp_Dbug;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
with Hostparm; use Hostparm;
with Lib; use Lib;
with Lib.Xref; use Lib.Xref;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Rtsfind; use Rtsfind;
with Targparm; use Targparm;
with Sinfo; use Sinfo;
with Sem; use Sem;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch7; use Sem_Ch7;
with Sem_Ch8; use Sem_Ch8;
with Sem_Res; use Sem_Res;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Snames; use Snames;
with Stand; use Stand;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Exp_Ch7 is
--------------------------------
-- Transient Scope Management --
--------------------------------
-- A transient scope is created when temporary objects are created by the
-- compiler. These temporary objects are allocated on the secondary stack
-- and the transient scope is responsible for finalizing the object when
-- appropriate and reclaiming the memory at the right time. The temporary
-- objects are generally the objects allocated to store the result of a
-- function returning an unconstrained or a tagged value. Expressions
-- needing to be wrapped in a transient scope (functions calls returning
-- unconstrained or tagged values) may appear in 3 different contexts which
-- lead to 3 different kinds of transient scope expansion:
-- 1. In a simple statement (procedure call, assignment, ...). In
-- this case the instruction is wrapped into a transient block.
-- (See Wrap_Transient_Statement for details)
-- 2. In an expression of a control structure (test in a IF statement,
-- expression in a CASE statement, ...).
-- (See Wrap_Transient_Expression for details)
-- 3. In a expression of an object_declaration. No wrapping is possible
-- here, so the finalization actions, if any are done right after the
-- declaration and the secondary stack deallocation is done in the
-- proper enclosing scope (see Wrap_Transient_Declaration for details)
-- Note about function returning tagged types: It has been decided to
-- always allocate their result in the secondary stack while it is not
-- absolutely mandatory when the tagged type is constrained because the
-- caller knows the size of the returned object and thus could allocate the
-- result in the primary stack. But, allocating them always in the
-- secondary stack simplifies many implementation hassles:
-- - If it is dispatching function call, the computation of the size of
-- the result is possible but complex from the outside.
-- - If the returned type is controlled, the assignment of the returned
-- value to the anonymous object involves an Adjust, and we have no
-- easy way to access the anonymous object created by the back-end
-- - If the returned type is class-wide, this is an unconstrained type
-- anyway
-- Furthermore, the little loss in efficiency which is the result of this
-- decision is not such a big deal because function returning tagged types
-- are not very much used in real life as opposed to functions returning
-- access to a tagged type
--------------------------------------------------
-- Transient Blocks and Finalization Management --
--------------------------------------------------
function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id;
-- N is a node wich may generate a transient scope. Loop over the
-- parent pointers of N until it find the appropriate node to
-- wrap. It it returns Empty, it means that no transient scope is
-- needed in this context.
function Make_Clean
(N : Node_Id;
Clean : Entity_Id;
Mark : Entity_Id;
Flist : Entity_Id;
Is_Task : Boolean;
Is_Master : Boolean;
Is_Protected_Subprogram : Boolean;
Is_Task_Allocation_Block : Boolean;
Is_Asynchronous_Call_Block : Boolean)
return Node_Id;
-- Expand a the clean-up procedure for controlled and/or transient
-- block, and/or task master or task body, or blocks used to
-- implement task allocation or asynchronous entry calls, or
-- procedures used to implement protected procedures. Clean is the
-- entity for such a procedure. Mark is the entity for the secondary
-- stack mark, if empty only controlled block clean-up will be
-- performed. Flist is the entity for the local final list, if empty
-- only transient scope clean-up will be performed. The flags
-- Is_Task and Is_Master control the calls to the corresponding
-- finalization actions for a task body or for an entity that is a
-- task master.
procedure Set_Node_To_Be_Wrapped (N : Node_Id);
-- Set the field Node_To_Be_Wrapped of the current scope
procedure Insert_Actions_In_Scope_Around (N : Node_Id);
-- Insert the before-actions kept in the scope stack before N, and the
-- after after-actions, after N which must be a member of a list.
function Make_Transient_Block
(Loc : Source_Ptr;
Action : Node_Id)
return Node_Id;
-- Create a transient block whose name is Scope, which is also a
-- controlled block if Flist is not empty and whose only code is
-- Action (either a single statement or single declaration).
type Final_Primitives is (Initialize_Case, Adjust_Case, Finalize_Case);
-- This enumeration type is defined in order to ease sharing code for
-- building finalization procedures for composite types.
Name_Of : constant array (Final_Primitives) of Name_Id :=
(Initialize_Case => Name_Initialize,
Adjust_Case => Name_Adjust,
Finalize_Case => Name_Finalize);
Deep_Name_Of : constant array (Final_Primitives) of Name_Id :=
(Initialize_Case => Name_uDeep_Initialize,
Adjust_Case => Name_uDeep_Adjust,
Finalize_Case => Name_uDeep_Finalize);
procedure Build_Record_Deep_Procs (Typ : Entity_Id);
-- Build the deep Initialize/Adjust/Finalize for a record Typ with
-- Has_Component_Component set and store them using the TSS mechanism.
procedure Build_Array_Deep_Procs (Typ : Entity_Id);
-- Build the deep Initialize/Adjust/Finalize for a record Typ with
-- Has_Controlled_Component set and store them using the TSS mechanism.
function Make_Deep_Proc
(Prim : Final_Primitives;
Typ : Entity_Id;
Stmts : List_Id)
return Node_Id;
-- This function generates the tree for Deep_Initialize, Deep_Adjust
-- or Deep_Finalize procedures according to the first parameter,
-- these procedures operate on the type Typ. The Stmts parameter
-- gives the body of the procedure.
function Make_Deep_Array_Body
(Prim : Final_Primitives;
Typ : Entity_Id)
return List_Id;
-- This function generates the list of statements for implementing
-- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures
-- according to the first parameter, these procedures operate on the
-- array type Typ.
function Make_Deep_Record_Body
(Prim : Final_Primitives;
Typ : Entity_Id)
return List_Id;
-- This function generates the list of statements for implementing
-- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures
-- according to the first parameter, these procedures operate on the
-- record type Typ.
function Convert_View
(Proc : Entity_Id;
Arg : Node_Id;
Ind : Pos := 1)
return Node_Id;
-- Proc is one of the Initialize/Adjust/Finalize operations, and
-- Arg is the argument being passed to it. Ind indicates which
-- formal of procedure Proc we are trying to match. This function
-- will, if necessary, generate an conversion between the partial
-- and full view of Arg to match the type of the formal of Proc,
-- or force a conversion to the class-wide type in the case where
-- the operation is abstract.
-----------------------------
-- Finalization Management --
-----------------------------
-- This part describe how Initialization/Adjusment/Finalization procedures
-- are generated and called. Two cases must be considered, types that are
-- Controlled (Is_Controlled flag set) and composite types that contain
-- controlled components (Has_Controlled_Component flag set). In the first
-- case the procedures to call are the user-defined primitive operations
-- Initialize/Adjust/Finalize. In the second case, GNAT generates
-- Deep_Initialize, Deep_Adjust and Deep_Finalize that are in charge of
-- calling the former procedures on the controlled components.
-- For records with Has_Controlled_Component set, a hidden "controller"
-- component is inserted. This controller component contains its own
-- finalization list on which all controlled components are attached
-- creating an indirection on the upper-level Finalization list. This
-- technique facilitates the management of objects whose number of
-- controlled components changes during execution. This controller
-- component is itself controlled and is attached to the upper-level
-- finalization chain. Its adjust primitive is in charge of calling
-- adjust on the components and adusting the finalization pointer to
-- match their new location (see a-finali.adb)
-- It is not possible to use a similar technique for arrays that have
-- Has_Controlled_Component set. In this case, deep procedures are
-- generated that call initialize/adjust/finalize + attachment or
-- detachment on the finalization list for all component.
-- Initialize calls: they are generated for declarations or dynamic
-- allocations of Controlled objects with no initial value. They are
-- always followed by an attachment to the current Finalization
-- Chain. For the dynamic allocation case this the chain attached to
-- the scope of the access type definition otherwise, this is the chain
-- of the current scope.
-- Adjust Calls: They are generated on 2 occasions: (1) for
-- declarations or dynamic allocations of Controlled objects with an
-- initial value. (2) after an assignment. In the first case they are
-- followed by an attachment to the final chain, in the second case
-- they are not.
-- Finalization Calls: They are generated on (1) scope exit, (2)
-- assignments, (3) unchecked deallocations. In case (3) they have to
-- be detached from the final chain, in case (2) they must not and in
-- case (1) this is not important since we are exiting the scope
-- anyway.
-- Here is a simple example of the expansion of a controlled block :
-- declare
-- X : Controlled ;
-- Y : Controlled := Init;
--
-- type R is record
-- C : Controlled;
-- end record;
-- W : R;
-- Z : R := (C => X);
-- begin
-- X := Y;
-- W := Z;
-- end;
--
-- is expanded into
--
-- declare
-- _L : System.FI.Finalizable_Ptr;
-- procedure _Clean is
-- begin
-- Abort_Defer;
-- System.FI.Finalize_List (_L);
-- Abort_Undefer;
-- end _Clean;
-- X : Controlled;
-- Initialize (X);
-- Attach_To_Final_List (_L, Finalizable (X), 1);
-- Y : Controlled := Init;
-- Adjust (Y);
-- Attach_To_Final_List (_L, Finalizable (Y), 1);
--
-- type R is record
-- _C : Record_Controller;
-- C : Controlled;
-- end record;
-- W : R;
-- Deep_Initialize (W, _L, 1);
-- Z : R := (C => X);
-- Deep_Adjust (Z, _L, 1);
-- begin
-- Finalize (X);
-- X := Y;
-- Adjust (X);
-- Deep_Finalize (W, False);
-- W := Z;
-- Deep_Adjust (W, _L, 0);
-- at end
-- _Clean;
-- end;
function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean;
-- Return True if Flist_Ref refers to a global final list, either
-- the object GLobal_Final_List which is used to attach standalone
-- objects, or any of the list controllers associated with library
-- level access to controlled objects
----------------------------
-- Build_Array_Deep_Procs --
----------------------------
procedure Build_Array_Deep_Procs (Typ : Entity_Id) is
begin
Set_TSS (Typ,
Make_Deep_Proc (
Prim => Initialize_Case,
Typ => Typ,
Stmts => Make_Deep_Array_Body (Initialize_Case, Typ)));
if not Is_Return_By_Reference_Type (Typ) then
Set_TSS (Typ,
Make_Deep_Proc (
Prim => Adjust_Case,
Typ => Typ,
Stmts => Make_Deep_Array_Body (Adjust_Case, Typ)));
end if;
Set_TSS (Typ,
Make_Deep_Proc (
Prim => Finalize_Case,
Typ => Typ,
Stmts => Make_Deep_Array_Body (Finalize_Case, Typ)));
end Build_Array_Deep_Procs;
-----------------------------
-- Build_Controlling_Procs --
-----------------------------
procedure Build_Controlling_Procs (Typ : Entity_Id) is
begin
if Is_Array_Type (Typ) then
Build_Array_Deep_Procs (Typ);
else pragma Assert (Is_Record_Type (Typ));
Build_Record_Deep_Procs (Typ);
end if;
end Build_Controlling_Procs;
----------------------
-- Build_Final_List --
----------------------
procedure Build_Final_List (N : Node_Id; Typ : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
begin
Set_Associated_Final_Chain (Typ,
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Typ), 'L')));
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier =>
Associated_Final_Chain (Typ),
Object_Definition =>
New_Reference_To
(RTE (RE_List_Controller), Loc)));
end Build_Final_List;
-----------------------------
-- Build_Record_Deep_Procs --
-----------------------------
procedure Build_Record_Deep_Procs (Typ : Entity_Id) is
begin
Set_TSS (Typ,
Make_Deep_Proc (
Prim => Initialize_Case,
Typ => Typ,
Stmts => Make_Deep_Record_Body (Initialize_Case, Typ)));
if not Is_Return_By_Reference_Type (Typ) then
Set_TSS (Typ,
Make_Deep_Proc (
Prim => Adjust_Case,
Typ => Typ,
Stmts => Make_Deep_Record_Body (Adjust_Case, Typ)));
end if;
Set_TSS (Typ,
Make_Deep_Proc (
Prim => Finalize_Case,
Typ => Typ,
Stmts => Make_Deep_Record_Body (Finalize_Case, Typ)));
end Build_Record_Deep_Procs;
---------------------
-- Controlled_Type --
---------------------
function Controlled_Type (T : Entity_Id) return Boolean is
begin
-- Class-wide types are considered controlled because they may contain
-- an extension that has controlled components
return (Is_Class_Wide_Type (T)
and then not No_Run_Time
and then not In_Finalization_Root (T))
or else Is_Controlled (T)
or else Has_Controlled_Component (T)
or else (Is_Concurrent_Type (T)
and then Present (Corresponding_Record_Type (T))
and then Controlled_Type (Corresponding_Record_Type (T)));
end Controlled_Type;
--------------------------
-- Controller_Component --
--------------------------
function Controller_Component (Typ : Entity_Id) return Entity_Id is
T : Entity_Id := Base_Type (Typ);
Comp : Entity_Id;
Comp_Scop : Entity_Id;
Res : Entity_Id := Empty;
Res_Scop : Entity_Id := Empty;
begin
if Is_Class_Wide_Type (T) then
T := Root_Type (T);
end if;
if Is_Private_Type (T) then
T := Underlying_Type (T);
end if;
-- Fetch the outermost controller
Comp := First_Entity (T);
while Present (Comp) loop
if Chars (Comp) = Name_uController then
Comp_Scop := Scope (Original_Record_Component (Comp));
-- If this controller is at the outermost level, no need to
-- look for another one
if Comp_Scop = T then
return Comp;
-- Otherwise record the outermost one and continue looking
elsif Res = Empty or else Is_Ancestor (Res_Scop, Comp_Scop) then
Res := Comp;
Res_Scop := Comp_Scop;
end if;
end if;
Next_Entity (Comp);
end loop;
-- If we fall through the loop, there is no controller component
return Res;
end Controller_Component;
------------------
-- Convert_View --
------------------
function Convert_View
(Proc : Entity_Id;
Arg : Node_Id;
Ind : Pos := 1)
return Node_Id
is
Fent : Entity_Id := First_Entity (Proc);
Ftyp : Entity_Id;
Atyp : Entity_Id;
begin
for J in 2 .. Ind loop
Next_Entity (Fent);
end loop;
Ftyp := Etype (Fent);
if Nkind (Arg) = N_Type_Conversion
or else Nkind (Arg) = N_Unchecked_Type_Conversion
then
Atyp := Entity (Subtype_Mark (Arg));
else
Atyp := Etype (Arg);
end if;
if Is_Abstract (Proc) and then Is_Tagged_Type (Ftyp) then
return Unchecked_Convert_To (Class_Wide_Type (Ftyp), Arg);
elsif Ftyp /= Atyp
and then Present (Atyp)
and then
(Is_Private_Type (Ftyp) or else Is_Private_Type (Atyp))
and then Underlying_Type (Atyp) = Underlying_Type (Ftyp)
then
return Unchecked_Convert_To (Ftyp, Arg);
-- If the argument is already a conversion, as generated by
-- Make_Init_Call, set the target type to the type of the formal
-- directly, to avoid spurious typing problems.
elsif (Nkind (Arg) = N_Unchecked_Type_Conversion
or else Nkind (Arg) = N_Type_Conversion)
and then not Is_Class_Wide_Type (Atyp)
then
Set_Subtype_Mark (Arg, New_Occurrence_Of (Ftyp, Sloc (Arg)));
Set_Etype (Arg, Ftyp);
return Arg;
else
return Arg;
end if;
end Convert_View;
-------------------------------
-- Establish_Transient_Scope --
-------------------------------
-- This procedure is called each time a transient block has to be inserted
-- that is to say for each call to a function with unconstrained ot tagged
-- result. It creates a new scope on the stack scope in order to enclose
-- all transient variables generated
procedure Establish_Transient_Scope (N : Node_Id; Sec_Stack : Boolean) is
Loc : constant Source_Ptr := Sloc (N);
Wrap_Node : Node_Id;
Sec_Stk : constant Boolean :=
Sec_Stack and not Functions_Return_By_DSP_On_Target;
-- We never need a secondary stack if functions return by DSP
begin
-- Do not create a transient scope if we are already inside one
for S in reverse Scope_Stack.First .. Scope_Stack.Last loop
if Scope_Stack.Table (S).Is_Transient then
if Sec_Stk then
Set_Uses_Sec_Stack (Scope_Stack.Table (S).Entity);
end if;
return;
-- If we have encountered Standard there are no enclosing
-- transient scopes.
elsif Scope_Stack.Table (S).Entity = Standard_Standard then
exit;
end if;
end loop;
Wrap_Node := Find_Node_To_Be_Wrapped (N);
-- Case of no wrap node, false alert, no transient scope needed
if No (Wrap_Node) then
null;
-- Transient scope is required
else
New_Scope (New_Internal_Entity (E_Block, Current_Scope, Loc, 'B'));
Set_Scope_Is_Transient;
if Sec_Stk then
Set_Uses_Sec_Stack (Current_Scope);
Check_Restriction (No_Secondary_Stack, N);
end if;
Set_Etype (Current_Scope, Standard_Void_Type);
Set_Node_To_Be_Wrapped (Wrap_Node);
if Debug_Flag_W then
Write_Str (" <Transient>");
Write_Eol;
end if;
end if;
end Establish_Transient_Scope;
----------------------------
-- Expand_Cleanup_Actions --
----------------------------
procedure Expand_Cleanup_Actions (N : Node_Id) is
Loc : Source_Ptr;
S : constant Entity_Id :=
Current_Scope;
Flist : constant Entity_Id :=
Finalization_Chain_Entity (S);
Is_Task : constant Boolean :=
(Nkind (Original_Node (N)) = N_Task_Body);
Is_Master : constant Boolean :=
Nkind (N) /= N_Entry_Body
and then Is_Task_Master (N);
Is_Protected : constant Boolean :=
Nkind (N) = N_Subprogram_Body
and then Is_Protected_Subprogram_Body (N);
Is_Task_Allocation : constant Boolean :=
Nkind (N) = N_Block_Statement
and then Is_Task_Allocation_Block (N);
Is_Asynchronous_Call : constant Boolean :=
Nkind (N) = N_Block_Statement
and then Is_Asynchronous_Call_Block (N);
Clean : Entity_Id;
Mark : Entity_Id := Empty;
New_Decls : List_Id := New_List;
Blok : Node_Id;
Wrapped : Boolean;
Chain : Entity_Id := Empty;
Decl : Node_Id;
Old_Poll : Boolean;
begin
-- Compute a location that is not directly in the user code in
-- order to avoid to generate confusing debug info. A good
-- approximation is the name of the outer user-defined scope
declare
S1 : Entity_Id := S;
begin
while not Comes_From_Source (S1) and then S1 /= Standard_Standard loop
S1 := Scope (S1);
end loop;
Loc := Sloc (S1);
end;
-- There are cleanup actions only if the secondary stack needs
-- releasing or some finalizations are needed or in the context
-- of tasking
if Uses_Sec_Stack (Current_Scope)
and then not Sec_Stack_Needed_For_Return (Current_Scope)
then
null;
elsif No (Flist)
and then not Is_Master
and then not Is_Task
and then not Is_Protected
and then not Is_Task_Allocation
and then not Is_Asynchronous_Call
then
return;
end if;
-- Set polling off, since we don't need to poll during cleanup
-- actions, and indeed for the cleanup routine, which is executed
-- with aborts deferred, we don't want polling.
Old_Poll := Polling_Required;
Polling_Required := False;
-- Make sure we have a declaration list, since we will add to it
if No (Declarations (N)) then
Set_Declarations (N, New_List);
end if;
-- The task activation call has already been built for task
-- allocation blocks.
if not Is_Task_Allocation then
Build_Task_Activation_Call (N);
end if;
if Is_Master then
Establish_Task_Master (N);
end if;
-- If secondary stack is in use, expand:
-- _Mxx : constant Mark_Id := SS_Mark;
-- Suppress calls to SS_Mark and SS_Release if Java_VM,
-- since we never use the secondary stack on the JVM.
if Uses_Sec_Stack (Current_Scope)
and then not Sec_Stack_Needed_For_Return (Current_Scope)
and then not Java_VM
then
Mark := Make_Defining_Identifier (Loc, New_Internal_Name ('M'));
Append_To (New_Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Mark,
Object_Definition => New_Reference_To (RTE (RE_Mark_Id), Loc),
Expression =>
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_SS_Mark), Loc))));
Set_Uses_Sec_Stack (Current_Scope, False);
end if;
-- If finalization list is present then expand:
-- Local_Final_List : System.FI.Finalizable_Ptr;
if Present (Flist) then
Append_To (New_Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Flist,
Object_Definition =>
New_Reference_To (RTE (RE_Finalizable_Ptr), Loc)));
end if;
-- Clean-up procedure definition
Clean := Make_Defining_Identifier (Loc, Name_uClean);
Set_Suppress_Elaboration_Warnings (Clean);
Append_To (New_Decls,
Make_Clean (N, Clean, Mark, Flist,
Is_Task,
Is_Master,
Is_Protected,
Is_Task_Allocation,
Is_Asynchronous_Call));
-- If exception handlers are present, wrap the Sequence of
-- statements in a block because it is not possible to get
-- exception handlers and an AT END call in the same scope.
if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then
Blok :=
Make_Block_Statement (Loc,
Handled_Statement_Sequence => Handled_Statement_Sequence (N));
Set_Handled_Statement_Sequence (N,
Make_Handled_Sequence_Of_Statements (Loc, New_List (Blok)));
Wrapped := True;
-- Otherwise we do not wrap
else
Wrapped := False;
Blok := Empty;
end if;
-- Don't move the _chain Activation_Chain declaration in task
-- allocation blocks. Task allocation blocks use this object
-- in their cleanup handlers, and gigi complains if it is declared
-- in the sequence of statements of the scope that declares the
-- handler.
if Is_Task_Allocation then
Chain := Activation_Chain_Entity (N);
Decl := First (Declarations (N));
while Nkind (Decl) /= N_Object_Declaration
or else Defining_Identifier (Decl) /= Chain
loop
Next (Decl);
pragma Assert (Present (Decl));
end loop;
Remove (Decl);
Prepend_To (New_Decls, Decl);
end if;
-- Now we move the declarations into the Sequence of statements
-- in order to get them protected by the AT END call. It may seem
-- weird to put declarations in the sequence of statement but in
-- fact nothing forbids that at the tree level. We also set the
-- First_Real_Statement field so that we remember where the real
-- statements (i.e. original statements) begin. Note that if we
-- wrapped the statements, the first real statement is inside the
-- inner block. If the First_Real_Statement is already set (as is
-- the case for subprogram bodies that are expansions of task bodies)
-- then do not reset it, because its declarative part would migrate
-- to the statement part.
if not Wrapped then
if No (First_Real_Statement (Handled_Statement_Sequence (N))) then
Set_First_Real_Statement (Handled_Statement_Sequence (N),
First (Statements (Handled_Statement_Sequence (N))));
end if;
else
Set_First_Real_Statement (Handled_Statement_Sequence (N), Blok);
end if;
Append_List_To (Declarations (N),
Statements (Handled_Statement_Sequence (N)));
Set_Statements (Handled_Statement_Sequence (N), Declarations (N));
-- We need to reset the Sloc of the handled statement sequence to
-- properly reflect the new initial "statement" in the sequence.
Set_Sloc
(Handled_Statement_Sequence (N), Sloc (First (Declarations (N))));
-- The declarations of the _Clean procedure and finalization chain
-- replace the old declarations that have been moved inward
Set_Declarations (N, New_Decls);
Analyze_Declarations (New_Decls);
-- The At_End call is attached to the sequence of statements.
declare
HSS : Node_Id;
begin
-- If the construct is a protected subprogram, then the call to
-- the corresponding unprotected program appears in a block which
-- is the last statement in the body, and it is this block that
-- must be covered by the At_End handler.
if Is_Protected then
HSS := Handled_Statement_Sequence
(Last (Statements (Handled_Statement_Sequence (N))));
else
HSS := Handled_Statement_Sequence (N);
end if;
Set_At_End_Proc (HSS, New_Occurrence_Of (Clean, Loc));
Expand_At_End_Handler (HSS, Empty);
end;
-- Restore saved polling mode
Polling_Required := Old_Poll;
end Expand_Cleanup_Actions;
-------------------------------
-- Expand_Ctrl_Function_Call --
-------------------------------
procedure Expand_Ctrl_Function_Call (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Rtype : constant Entity_Id := Etype (N);
Utype : constant Entity_Id := Underlying_Type (Rtype);
Ref : Node_Id;
Action : Node_Id;
Attach_Level : Uint := Uint_1;
Len_Ref : Node_Id := Empty;
function Last_Array_Component
(Ref : Node_Id;
Typ : Entity_Id)
return Node_Id;
-- Creates a reference to the last component of the array object
-- designated by Ref whose type is Typ.
function Last_Array_Component
(Ref : Node_Id;
Typ : Entity_Id)
return Node_Id
is
N : Int;
Index_List : List_Id := New_List;
begin
N := 1;
while N <= Number_Dimensions (Typ) loop
Append_To (Index_List,
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr (Ref),
Attribute_Name => Name_Last,
Expressions => New_List (
Make_Integer_Literal (Loc, N))));
N := N + 1;
end loop;
return
Make_Indexed_Component (Loc,
Prefix => Duplicate_Subexpr (Ref),
Expressions => Index_List);
end Last_Array_Component;
-- Start of processing for Expand_Ctrl_Function_Call
begin
-- Optimization, if the returned value (which is on the sec-stack)
-- is returned again, no need to copy/readjust/finalize, we can just
-- pass the value thru (see Expand_N_Return_Statement), and thus no
-- attachment is needed
if Nkind (Parent (N)) = N_Return_Statement then
return;
end if;
-- Resolution is now finished, make sure we don't start analysis again
-- because of the duplication
Set_Analyzed (N);
Ref := Duplicate_Subexpr (N);
-- Now we can generate the Attach Call, note that this value is
-- always in the (secondary) stack and thus is attached to a singly
-- linked final list:
--
-- Resx := F (X)'reference;
-- Attach_To_Final_List (_Lx, Resx.all, 1);
-- or when there are controlled components
-- Attach_To_Final_List (_Lx, Resx._controller, 1);
-- or if it is an array with is_controlled components
-- Attach_To_Final_List (_Lx, Resx (Resx'last), 3);
-- An attach level of 3 means that a whole array is to be
-- attached to the finalization list
-- or if it is an array with has_controlled components
-- Attach_To_Final_List (_Lx, Resx (Resx'last)._controller, 3);
if Has_Controlled_Component (Rtype) then
declare
T1 : Entity_Id := Rtype;
T2 : Entity_Id := Utype;
begin
if Is_Array_Type (T2) then
Len_Ref :=
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr (Unchecked_Convert_To (T2, Ref)),
Attribute_Name => Name_Length);
end if;
while Is_Array_Type (T2) loop
if T1 /= T2 then
Ref := Unchecked_Convert_To (T2, Ref);
end if;
Ref := Last_Array_Component (Ref, T2);
Attach_Level := Uint_3;
T1 := Component_Type (T2);
T2 := Underlying_Type (T1);
end loop;
if Has_Controlled_Component (T2) then
if T1 /= T2 then
Ref := Unchecked_Convert_To (T2, Ref);
end if;
Ref :=
Make_Selected_Component (Loc,
Prefix => Ref,
Selector_Name => Make_Identifier (Loc, Name_uController));
end if;
end;
-- Here we know that 'Ref' has a controller so we may as well
-- attach it directly
Action :=
Make_Attach_Call (
Obj_Ref => Ref,
Flist_Ref => Find_Final_List (Current_Scope),
With_Attach => Make_Integer_Literal (Loc, Attach_Level));
else
-- Here, we have a controlled type that does not seem to have
-- controlled components but it could be a class wide type whose
-- further derivations have controlled components. So we don't know
-- if the object itself needs to be attached or if it
-- has a record controller. We need to call a runtime function
-- (Deep_Tag_Attach) which knows what to do thanks to the
-- RC_Offset in the dispatch table.
Action :=
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Deep_Tag_Attach), Loc),
Parameter_Associations => New_List (
Find_Final_List (Current_Scope),
Make_Attribute_Reference (Loc,
Prefix => Ref,
Attribute_Name => Name_Address),
Make_Integer_Literal (Loc, Attach_Level)));
end if;
if Present (Len_Ref) then
Action :=
Make_Implicit_If_Statement (N,
Condition => Make_Op_Gt (Loc,
Left_Opnd => Len_Ref,
Right_Opnd => Make_Integer_Literal (Loc, 0)),
Then_Statements => New_List (Action));
end if;
Insert_Action (N, Action);
end Expand_Ctrl_Function_Call;
---------------------------
-- Expand_N_Package_Body --
---------------------------
-- Add call to Activate_Tasks if body is an activator (actual
-- processing is in chapter 9).
-- Generate subprogram descriptor for elaboration routine
-- ENcode entity names in package body
procedure Expand_N_Package_Body (N : Node_Id) is
Ent : Entity_Id := Corresponding_Spec (N);
begin
-- This is done only for non-generic packages
if Ekind (Ent) = E_Package then
New_Scope (Corresponding_Spec (N));
Build_Task_Activation_Call (N);
Pop_Scope;
end if;
Set_Elaboration_Flag (N, Corresponding_Spec (N));
-- Generate a subprogram descriptor for the elaboration routine of
-- a package body if the package body has no pending instantiations
-- and it has generated at least one exception handler
if Present (Handler_Records (Body_Entity (Ent)))
and then Is_Compilation_Unit (Ent)
and then not Delay_Subprogram_Descriptors (Body_Entity (Ent))
then
Generate_Subprogram_Descriptor_For_Package
(N, Body_Entity (Ent));
end if;
Set_In_Package_Body (Ent, False);
-- Set to encode entity names in package body before gigi is called
Qualify_Entity_Names (N);
end Expand_N_Package_Body;
----------------------------------
-- Expand_N_Package_Declaration --
----------------------------------
-- Add call to Activate_Tasks if there are tasks declared and the
-- package has no body. Note that in Ada83, this may result in
-- premature activation of some tasks, given that we cannot tell
-- whether a body will eventually appear.
procedure Expand_N_Package_Declaration (N : Node_Id) is
begin
if Nkind (Parent (N)) = N_Compilation_Unit
and then not Body_Required (Parent (N))
and then not Unit_Requires_Body (Defining_Entity (N))
and then Present (Activation_Chain_Entity (N))
then
New_Scope (Defining_Entity (N));
Build_Task_Activation_Call (N);
Pop_Scope;
end if;
-- Note: it is not necessary to worry about generating a subprogram
-- descriptor, since the only way to get exception handlers into a
-- package spec is to include instantiations, and that would cause
-- generation of subprogram descriptors to be delayed in any case.
-- Set to encode entity names in package spec before gigi is called
Qualify_Entity_Names (N);
end Expand_N_Package_Declaration;
---------------------
-- Find_Final_List --
---------------------
function Find_Final_List
(E : Entity_Id;
Ref : Node_Id := Empty)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (Ref);
S : Entity_Id;
Id : Entity_Id;
R : Node_Id;
begin
-- Case of an internal component. The Final list is the record
-- controller of the enclosing record
if Present (Ref) then
R := Ref;
loop
case Nkind (R) is
when N_Unchecked_Type_Conversion | N_Type_Conversion =>
R := Expression (R);
when N_Indexed_Component | N_Explicit_Dereference =>
R := Prefix (R);
when N_Selected_Component =>
R := Prefix (R);
exit;
when N_Identifier =>
exit;
when others =>
raise Program_Error;
end case;
end loop;
return
Make_Selected_Component (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix => R,
Selector_Name => Make_Identifier (Loc, Name_uController)),
Selector_Name => Make_Identifier (Loc, Name_F));
-- Case of a dynamically allocated object. The final list is the
-- corresponding list controller (The next entity in the scope of
-- the access type with the right type). If the type comes from a
-- With_Type clause, no controller was created, and we use the
-- global chain instead.
elsif Is_Access_Type (E) then
if not From_With_Type (E) then
return
Make_Selected_Component (Loc,
Prefix =>
New_Reference_To
(Associated_Final_Chain (Base_Type (E)), Loc),
Selector_Name => Make_Identifier (Loc, Name_F));
else
return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E));
end if;
else
if Is_Dynamic_Scope (E) then
S := E;
else
S := Enclosing_Dynamic_Scope (E);
end if;
-- When the finalization chain entity is 'Error', it means that
-- there should not be any chain at that level and that the
-- enclosing one should be used
-- This is a nasty kludge, see ??? note in exp_ch11
while Finalization_Chain_Entity (S) = Error loop
S := Enclosing_Dynamic_Scope (S);
end loop;
if S = Standard_Standard then
return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E));
else
if No (Finalization_Chain_Entity (S)) then
Id := Make_Defining_Identifier (Sloc (S),
New_Internal_Name ('F'));
Set_Finalization_Chain_Entity (S, Id);
-- Set momentarily some semantics attributes to allow normal
-- analysis of expansions containing references to this chain.
-- Will be fully decorated during the expansion of the scope
-- itself
Set_Ekind (Id, E_Variable);
Set_Etype (Id, RTE (RE_Finalizable_Ptr));
end if;
return New_Reference_To (Finalization_Chain_Entity (S), Sloc (E));
end if;
end if;
end Find_Final_List;
-----------------------------
-- Find_Node_To_Be_Wrapped --
-----------------------------
function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id is
P : Node_Id;
The_Parent : Node_Id;
begin
The_Parent := N;
loop
P := The_Parent;
pragma Assert (P /= Empty);
The_Parent := Parent (P);
case Nkind (The_Parent) is
-- Simple statement can be wrapped
when N_Pragma =>
return The_Parent;
-- Usually assignments are good candidate for wrapping
-- except when they have been generated as part of a
-- controlled aggregate where the wrapping should take
-- place more globally.
when N_Assignment_Statement =>
if No_Ctrl_Actions (The_Parent) then
null;
else
return The_Parent;
end if;
-- An entry call statement is a special case if it occurs in
-- the context of a Timed_Entry_Call. In this case we wrap
-- the entire timed entry call.
when N_Entry_Call_Statement |
N_Procedure_Call_Statement =>
if Nkind (Parent (The_Parent)) = N_Entry_Call_Alternative
and then
Nkind (Parent (Parent (The_Parent))) = N_Timed_Entry_Call
then
return Parent (Parent (The_Parent));
else
return The_Parent;
end if;
-- Object declarations are also a boundary for the transient scope
-- even if they are not really wrapped
-- (see Wrap_Transient_Declaration)
when N_Object_Declaration |
N_Object_Renaming_Declaration |
N_Subtype_Declaration =>
return The_Parent;
-- The expression itself is to be wrapped if its parent is a
-- compound statement or any other statement where the expression
-- is known to be scalar
when N_Accept_Alternative |
N_Attribute_Definition_Clause |
N_Case_Statement |
N_Code_Statement |
N_Delay_Alternative |
N_Delay_Until_Statement |
N_Delay_Relative_Statement |
N_Discriminant_Association |
N_Elsif_Part |
N_Entry_Body_Formal_Part |
N_Exit_Statement |
N_If_Statement |
N_Iteration_Scheme |
N_Terminate_Alternative =>
return P;
when N_Attribute_Reference =>
if Is_Procedure_Attribute_Name
(Attribute_Name (The_Parent))
then
return The_Parent;
end if;
-- ??? No scheme yet for "for I in Expression'Range loop"
-- ??? the current scheme for Expression wrapping doesn't apply
-- ??? because a RANGE is NOT an expression. Tricky problem...
-- ??? while this problem is not solved we have a potential for
-- ??? leak and unfinalized intermediate objects here.
when N_Loop_Parameter_Specification =>
return Empty;
-- The following nodes contains "dummy calls" which don't
-- need to be wrapped.
when N_Parameter_Specification |
N_Discriminant_Specification |
N_Component_Declaration =>
return Empty;
-- The return statement is not to be wrapped when the function
-- itself needs wrapping at the outer-level
when N_Return_Statement =>
if Requires_Transient_Scope (Return_Type (The_Parent)) then
return Empty;
else
return The_Parent;
end if;
-- If we leave a scope without having been able to find a node to
-- wrap, something is going wrong but this can happen in error
-- situation that are not detected yet (such as a dynamic string
-- in a pragma export)
when N_Subprogram_Body |
N_Package_Declaration |
N_Package_Body |
N_Block_Statement =>
return Empty;
-- otherwise continue the search
when others =>
null;
end case;
end loop;
end Find_Node_To_Be_Wrapped;
----------------------
-- Global_Flist_Ref --
----------------------
function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean is
Flist : Entity_Id;
begin
-- Look for the Global_Final_List
if Is_Entity_Name (Flist_Ref) then
Flist := Entity (Flist_Ref);
-- Look for the final list associated with an access to controlled
elsif Nkind (Flist_Ref) = N_Selected_Component
and then Is_Entity_Name (Prefix (Flist_Ref))
then
Flist := Entity (Prefix (Flist_Ref));
else
return False;
end if;
return Present (Flist)
and then Present (Scope (Flist))
and then Enclosing_Dynamic_Scope (Flist) = Standard_Standard;
end Global_Flist_Ref;
----------------------------------
-- Has_New_Controlled_Component --
----------------------------------
function Has_New_Controlled_Component (E : Entity_Id) return Boolean is
Comp : Entity_Id;
begin
if not Is_Tagged_Type (E) then
return Has_Controlled_Component (E);
elsif not Is_Derived_Type (E) then
return Has_Controlled_Component (E);
end if;
Comp := First_Component (E);
while Present (Comp) loop
if Chars (Comp) = Name_uParent then
null;
elsif Scope (Original_Record_Component (Comp)) = E
and then Controlled_Type (Etype (Comp))
then
return True;
end if;
Next_Component (Comp);
end loop;
return False;
end Has_New_Controlled_Component;
--------------------------
-- In_Finalization_Root --
--------------------------
-- It would seem simpler to test Scope (RTE (RE_Root_Controlled)) but
-- the purpose of this function is to avoid a circular call to Rtsfind
-- which would been caused by such a test.
function In_Finalization_Root (E : Entity_Id) return Boolean is
S : constant Entity_Id := Scope (E);
begin
return Chars (Scope (S)) = Name_System
and then Chars (S) = Name_Finalization_Root
and then Scope (Scope (S)) = Standard_Standard;
end In_Finalization_Root;
------------------------------------
-- Insert_Actions_In_Scope_Around --
------------------------------------
procedure Insert_Actions_In_Scope_Around (N : Node_Id) is
SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
begin
if Present (SE.Actions_To_Be_Wrapped_Before) then
Insert_List_Before (N, SE.Actions_To_Be_Wrapped_Before);
SE.Actions_To_Be_Wrapped_Before := No_List;
end if;
if Present (SE.Actions_To_Be_Wrapped_After) then
Insert_List_After (N, SE.Actions_To_Be_Wrapped_After);
SE.Actions_To_Be_Wrapped_After := No_List;
end if;
end Insert_Actions_In_Scope_Around;
-----------------------
-- Make_Adjust_Call --
-----------------------
function Make_Adjust_Call
(Ref : Node_Id;
Typ : Entity_Id;
Flist_Ref : Node_Id;
With_Attach : Node_Id)
return List_Id
is
Loc : constant Source_Ptr := Sloc (Ref);
Res : constant List_Id := New_List;
Utyp : Entity_Id;
Proc : Entity_Id;
Cref : Node_Id := Ref;
Cref2 : Node_Id;
Attach : Node_Id := With_Attach;
begin
if Is_Class_Wide_Type (Typ) then
Utyp := Underlying_Type (Base_Type (Root_Type (Typ)));
else
Utyp := Underlying_Type (Base_Type (Typ));
end if;
Set_Assignment_OK (Cref);
-- Deal with non-tagged derivation of private views
if Is_Untagged_Derivation (Typ) then
Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
Cref := Unchecked_Convert_To (Utyp, Cref);
Set_Assignment_OK (Cref);
-- To prevent problems with UC see 1.156 RH ???
end if;
-- If the underlying_type is a subtype, we are dealing with
-- the completion of a private type. We need to access
-- the base type and generate a conversion to it.
if Utyp /= Base_Type (Utyp) then
pragma Assert (Is_Private_Type (Typ));
Utyp := Base_Type (Utyp);
Cref := Unchecked_Convert_To (Utyp, Cref);
end if;
-- We do not need to attach to one of the Global Final Lists
-- the objects whose type is Finalize_Storage_Only
if Finalize_Storage_Only (Typ)
and then (Global_Flist_Ref (Flist_Ref)
or else Entity (Constant_Value (RTE (RE_Garbage_Collected)))
= Standard_True)
then
Attach := Make_Integer_Literal (Loc, 0);
end if;
-- Generate:
-- Deep_Adjust (Flist_Ref, Ref, With_Attach);
if Has_Controlled_Component (Utyp)
or else Is_Class_Wide_Type (Typ)
then
if Is_Tagged_Type (Utyp) then
Proc := Find_Prim_Op (Utyp, Deep_Name_Of (Adjust_Case));
else
Proc := TSS (Utyp, Deep_Name_Of (Adjust_Case));
end if;
Cref := Convert_View (Proc, Cref, 2);
Append_To (Res,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Proc, Loc),
Parameter_Associations =>
New_List (Flist_Ref, Cref, Attach)));
-- Generate:
-- if With_Attach then
-- Attach_To_Final_List (Ref, Flist_Ref);
-- end if;
-- Adjust (Ref);
else -- Is_Controlled (Utyp)
Proc := Find_Prim_Op (Utyp, Name_Of (Adjust_Case));
Cref := Convert_View (Proc, Cref);
Cref2 := New_Copy_Tree (Cref);
Append_To (Res,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Proc, Loc),
Parameter_Associations => New_List (Cref2)));
Append_To (Res, Make_Attach_Call (Cref, Flist_Ref, Attach));
-- Treat this as a reference to Adjust if the Adjust routine
-- comes from source. The call is not explicit, but it is near
-- enough, and we won't typically get explicit adjust calls.
if Comes_From_Source (Proc) then
Generate_Reference (Proc, Ref);
end if;
end if;
return Res;
end Make_Adjust_Call;
----------------------
-- Make_Attach_Call --
----------------------
-- Generate:
-- System.FI.Attach_To_Final_List (Flist, Ref, Nb_Link)
function Make_Attach_Call
(Obj_Ref : Node_Id;
Flist_Ref : Node_Id;
With_Attach : Node_Id)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (Obj_Ref);
begin
-- Optimization: If the number of links is statically '0', don't
-- call the attach_proc.
if Nkind (With_Attach) = N_Integer_Literal
and then Intval (With_Attach) = Uint_0
then
return Make_Null_Statement (Loc);
end if;
return
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Attach_To_Final_List), Loc),
Parameter_Associations => New_List (
Flist_Ref,
OK_Convert_To (RTE (RE_Finalizable), Obj_Ref),
With_Attach));
end Make_Attach_Call;
----------------
-- Make_Clean --
----------------
function Make_Clean
(N : Node_Id;
Clean : Entity_Id;
Mark : Entity_Id;
Flist : Entity_Id;
Is_Task : Boolean;
Is_Master : Boolean;
Is_Protected_Subprogram : Boolean;
Is_Task_Allocation_Block : Boolean;
Is_Asynchronous_Call_Block : Boolean)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (Clean);
Stmt : List_Id := New_List;
Sbody : Node_Id;
Spec : Node_Id;
Name : Node_Id;
Param : Node_Id;
Unlock : Node_Id;
Param_Type : Entity_Id;
Pid : Entity_Id := Empty;
Cancel_Param : Entity_Id;
begin
if Is_Task then
if Restricted_Profile then
Append_To
(Stmt, Build_Runtime_Call (Loc, RE_Complete_Restricted_Task));
else
Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Task));
end if;
elsif Is_Master then
if Restrictions (No_Task_Hierarchy) = False then
Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Master));
end if;
elsif Is_Protected_Subprogram then
-- Add statements to the cleanup handler of the (ordinary)
-- subprogram expanded to implement a protected subprogram,
-- unlocking the protected object parameter and undeferring abortion.
-- If this is a protected procedure, and the object contains
-- entries, this also calls the entry service routine.
-- NOTE: This cleanup handler references _object, a parameter
-- to the procedure.
-- Find the _object parameter representing the protected object.
Spec := Parent (Corresponding_Spec (N));
Param := First (Parameter_Specifications (Spec));
loop
Param_Type := Etype (Parameter_Type (Param));
if Ekind (Param_Type) = E_Record_Type then
Pid := Corresponding_Concurrent_Type (Param_Type);
end if;
exit when not Present (Param) or else Present (Pid);
Next (Param);
end loop;
pragma Assert (Present (Param));
-- If the associated protected object declares entries,
-- a protected procedure has to service entry queues.
-- In this case, add
-- Service_Entries (_object._object'Access);
-- _object is the record used to implement the protected object.
-- It is a parameter to the protected subprogram.
if Nkind (Specification (N)) = N_Procedure_Specification
and then Has_Entries (Pid)
then
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Pid) > 1
then
Name := New_Reference_To (RTE (RE_Service_Entries), Loc);
else
Name := New_Reference_To (RTE (RE_Service_Entry), Loc);
end if;
Append_To (Stmt,
Make_Procedure_Call_Statement (Loc,
Name => Name,
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix => New_Reference_To (
Defining_Identifier (Param), Loc),
Selector_Name =>
Make_Identifier (Loc, Name_uObject)),
Attribute_Name => Name_Unchecked_Access))));
end if;
-- Unlock (_object._object'Access);
-- _object is the record used to implement the protected object.
-- It is a parameter to the protected subprogram.
-- If the protected object is controlled (i.e it has entries or
-- needs finalization for interrupt handling), call Unlock_Entries,
-- except if the protected object follows the ravenscar profile, in
-- which case call Unlock_Entry, otherwise call the simplified
-- version, Unlock.
if Has_Entries (Pid)
or else Has_Interrupt_Handler (Pid)
or else Has_Attach_Handler (Pid)
then
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Pid) > 1
then
Unlock := New_Reference_To (RTE (RE_Unlock_Entries), Loc);
else
Unlock := New_Reference_To (RTE (RE_Unlock_Entry), Loc);
end if;
else
Unlock := New_Reference_To (RTE (RE_Unlock), Loc);
end if;
Append_To (Stmt,
Make_Procedure_Call_Statement (Loc,
Name => Unlock,
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix =>
New_Reference_To (Defining_Identifier (Param), Loc),
Selector_Name =>
Make_Identifier (Loc, Name_uObject)),
Attribute_Name => Name_Unchecked_Access))));
if Abort_Allowed then
-- Abort_Undefer;
Append_To (Stmt,
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To (
RTE (RE_Abort_Undefer), Loc),
Parameter_Associations => Empty_List));
end if;
elsif Is_Task_Allocation_Block then
-- Add a call to Expunge_Unactivated_Tasks to the cleanup
-- handler of a block created for the dynamic allocation of
-- tasks:
-- Expunge_Unactivated_Tasks (_chain);
-- where _chain is the list of tasks created by the allocator
-- but not yet activated. This list will be empty unless
-- the block completes abnormally.
-- This only applies to dynamically allocated tasks;
-- other unactivated tasks are completed by Complete_Task or
-- Complete_Master.
-- NOTE: This cleanup handler references _chain, a local
-- object.
Append_To (Stmt,
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To (
RTE (RE_Expunge_Unactivated_Tasks), Loc),
Parameter_Associations => New_List (
New_Reference_To (Activation_Chain_Entity (N), Loc))));
elsif Is_Asynchronous_Call_Block then
-- Add a call to attempt to cancel the asynchronous entry call
-- whenever the block containing the abortable part is exited.
-- NOTE: This cleanup handler references C, a local object
-- Get the argument to the Cancel procedure
Cancel_Param := Entry_Cancel_Parameter (Entity (Identifier (N)));
-- If it is of type Communication_Block, this must be a
-- protected entry call.
if Is_RTE (Etype (Cancel_Param), RE_Communication_Block) then
Append_To (Stmt,
-- if Enqueued (Cancel_Parameter) then
Make_Implicit_If_Statement (Clean,
Condition => Make_Function_Call (Loc,
Name => New_Reference_To (
RTE (RE_Enqueued), Loc),
Parameter_Associations => New_List (
New_Reference_To (Cancel_Param, Loc))),
Then_Statements => New_List (
-- Cancel_Protected_Entry_Call (Cancel_Param);
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
RTE (RE_Cancel_Protected_Entry_Call), Loc),
Parameter_Associations => New_List (
New_Reference_To (Cancel_Param, Loc))))));
-- Asynchronous delay
elsif Is_RTE (Etype (Cancel_Param), RE_Delay_Block) then
Append_To (Stmt,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Cancel_Async_Delay), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Cancel_Param, Loc),
Attribute_Name => Name_Unchecked_Access))));
-- Task entry call
else
-- Append call to Cancel_Task_Entry_Call (C);
Append_To (Stmt,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
RTE (RE_Cancel_Task_Entry_Call),
Loc),
Parameter_Associations => New_List (
New_Reference_To (Cancel_Param, Loc))));
end if;
end if;
if Present (Flist) then
Append_To (Stmt,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Finalize_List), Loc),
Parameter_Associations => New_List (
New_Reference_To (Flist, Loc))));
end if;
if Present (Mark) then
Append_To (Stmt,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_SS_Release), Loc),
Parameter_Associations => New_List (
New_Reference_To (Mark, Loc))));
end if;
Sbody :=
Make_Subprogram_Body (Loc,
Specification =>
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Clean),
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmt));
if Present (Flist) or else Is_Task or else Is_Master then
Wrap_Cleanup_Procedure (Sbody);
end if;
-- We do not want debug information for _Clean routines,
-- since it just confuses the debugging operation unless
-- we are debugging generated code.
if not Debug_Generated_Code then
Set_Debug_Info_Off (Clean, True);
end if;
return Sbody;
end Make_Clean;
--------------------------
-- Make_Deep_Array_Body --
--------------------------
-- Array components are initialized and adjusted in the normal order
-- and finalized in the reverse order. Exceptions are handled and
-- Program_Error is re-raise in the Adjust and Finalize case
-- (RM 7.6.1(12)). Generate the following code :
--
-- procedure Deep_<P> -- with <P> being Initialize or Adjust or Finalize
-- (L : in out Finalizable_Ptr;
-- V : in out Typ)
-- is
-- begin
-- for J1 in Typ'First (1) .. Typ'Last (1) loop
-- ^ reverse ^ -- in the finalization case
-- ...
-- for J2 in Typ'First (n) .. Typ'Last (n) loop
-- Make_<P>_Call (Typ, V (J1, .. , Jn), L, V);
-- end loop;
-- ...
-- end loop;
-- exception -- not in the
-- when others => raise Program_Error; -- Initialize case
-- end Deep_<P>;
function Make_Deep_Array_Body
(Prim : Final_Primitives;
Typ : Entity_Id)
return List_Id
is
Loc : constant Source_Ptr := Sloc (Typ);
Index_List : constant List_Id := New_List;
-- Stores the list of references to the indexes (one per dimension)
function One_Component return List_Id;
-- Create one statement to initialize/adjust/finalize one array
-- component, designated by a full set of indices.
function One_Dimension (N : Int) return List_Id;
-- Create loop to deal with one dimension of the array. The single
-- statement in the body of the loop initializes the inner dimensions if
-- any, or else a single component.
-------------------
-- One_Component --
-------------------
function One_Component return List_Id is
Comp_Typ : constant Entity_Id := Component_Type (Typ);
Comp_Ref : constant Node_Id :=
Make_Indexed_Component (Loc,
Prefix => Make_Identifier (Loc, Name_V),
Expressions => Index_List);
begin
-- Set the etype of the component Reference, which is used to
-- determine whether a conversion to a parent type is needed.
Set_Etype (Comp_Ref, Comp_Typ);
case Prim is
when Initialize_Case =>
return Make_Init_Call (Comp_Ref, Comp_Typ,
Make_Identifier (Loc, Name_L),
Make_Identifier (Loc, Name_B));
when Adjust_Case =>
return Make_Adjust_Call (Comp_Ref, Comp_Typ,
Make_Identifier (Loc, Name_L),
Make_Identifier (Loc, Name_B));
when Finalize_Case =>
return Make_Final_Call (Comp_Ref, Comp_Typ,
Make_Identifier (Loc, Name_B));
end case;
end One_Component;
-------------------
-- One_Dimension --
-------------------
function One_Dimension (N : Int) return List_Id is
Index : Entity_Id;
begin
if N > Number_Dimensions (Typ) then
return One_Component;
else
Index :=
Make_Defining_Identifier (Loc, New_External_Name ('J', N));
Append_To (Index_List, New_Reference_To (Index, Loc));
return New_List (
Make_Implicit_Loop_Statement (Typ,
Identifier => Empty,
Iteration_Scheme =>
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification (Loc,
Defining_Identifier => Index,
Discrete_Subtype_Definition =>
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Name_V),
Attribute_Name => Name_Range,
Expressions => New_List (
Make_Integer_Literal (Loc, N))),
Reverse_Present => Prim = Finalize_Case)),
Statements => One_Dimension (N + 1)));
end if;
end One_Dimension;
-- Start of processing for Make_Deep_Array_Body
begin
return One_Dimension (1);
end Make_Deep_Array_Body;
--------------------
-- Make_Deep_Proc --
--------------------
-- Generate:
-- procedure DEEP_<prim>
-- (L : IN OUT Finalizable_Ptr; -- not for Finalize
-- V : IN OUT <typ>;
-- B : IN Short_Short_Integer) is
-- begin
-- <stmts>;
-- exception -- Finalize and Adjust Cases only
-- raise Program_Error; -- idem
-- end DEEP_<prim>;
function Make_Deep_Proc
(Prim : Final_Primitives;
Typ : Entity_Id;
Stmts : List_Id)
return Entity_Id
is
Loc : constant Source_Ptr := Sloc (Typ);
Formals : List_Id;
Proc_Name : Entity_Id;
Handler : List_Id := No_List;
Subp_Body : Node_Id;
Type_B : Entity_Id;
begin
if Prim = Finalize_Case then
Formals := New_List;
Type_B := Standard_Boolean;
else
Formals := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Defining_Identifier (Loc, Name_L),
In_Present => True,
Out_Present => True,
Parameter_Type =>
New_Reference_To (RTE (RE_Finalizable_Ptr), Loc)));
Type_B := Standard_Short_Short_Integer;
end if;
Append_To (Formals,
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
In_Present => True,
Out_Present => True,
Parameter_Type => New_Reference_To (Typ, Loc)));
Append_To (Formals,
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Defining_Identifier (Loc, Name_B),
Parameter_Type => New_Reference_To (Type_B, Loc)));
if Prim = Finalize_Case or else Prim = Adjust_Case then
Handler := New_List (
Make_Exception_Handler (Loc,
Exception_Choices => New_List (Make_Others_Choice (Loc)),
Statements => New_List (
Make_Raise_Program_Error (Loc))));
end if;
Proc_Name := Make_Defining_Identifier (Loc, Deep_Name_Of (Prim));
Subp_Body :=
Make_Subprogram_Body (Loc,
Specification =>
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Proc_Name,
Parameter_Specifications => Formals),
Declarations => Empty_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts,
Exception_Handlers => Handler));
return Proc_Name;
end Make_Deep_Proc;
---------------------------
-- Make_Deep_Record_Body --
---------------------------
-- The Deep procedures call the appropriate Controlling proc on the
-- the controller component. In the init case, it also attach the
-- controller to the current finalization list.
function Make_Deep_Record_Body
(Prim : Final_Primitives;
Typ : Entity_Id)
return List_Id
is
Loc : constant Source_Ptr := Sloc (Typ);
Controller_Typ : Entity_Id;
Obj_Ref : constant Node_Id := Make_Identifier (Loc, Name_V);
Controller_Ref : constant Node_Id :=
Make_Selected_Component (Loc,
Prefix => Obj_Ref,
Selector_Name =>
Make_Identifier (Loc, Name_uController));
begin
if Is_Return_By_Reference_Type (Typ) then
Controller_Typ := RTE (RE_Limited_Record_Controller);
else
Controller_Typ := RTE (RE_Record_Controller);
end if;
case Prim is
when Initialize_Case =>
declare
Res : constant List_Id := New_List;
begin
Append_List_To (Res,
Make_Init_Call (
Ref => Controller_Ref,
Typ => Controller_Typ,
Flist_Ref => Make_Identifier (Loc, Name_L),
With_Attach => Make_Identifier (Loc, Name_B)));
-- When the type is also a controlled type by itself,
-- Initialize it and attach it at the end of the internal
-- finalization chain
if Is_Controlled (Typ) then
Append_To (Res,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
Find_Prim_Op (Typ, Name_Of (Prim)), Loc),
Parameter_Associations =>
New_List (New_Copy_Tree (Obj_Ref))));
Append_To (Res, Make_Attach_Call (
Obj_Ref => New_Copy_Tree (Obj_Ref),
Flist_Ref =>
Make_Selected_Component (Loc,
Prefix => New_Copy_Tree (Controller_Ref),
Selector_Name => Make_Identifier (Loc, Name_F)),
With_Attach => Make_Integer_Literal (Loc, 1)));
end if;
return Res;
end;
when Adjust_Case =>
return
Make_Adjust_Call (Controller_Ref, Controller_Typ,
Make_Identifier (Loc, Name_L),
Make_Identifier (Loc, Name_B));
when Finalize_Case =>
return
Make_Final_Call (Controller_Ref, Controller_Typ,
Make_Identifier (Loc, Name_B));
end case;
end Make_Deep_Record_Body;
----------------------
-- Make_Final_Call --
----------------------
function Make_Final_Call
(Ref : Node_Id;
Typ : Entity_Id;
With_Detach : Node_Id)
return List_Id
is
Loc : constant Source_Ptr := Sloc (Ref);
Res : constant List_Id := New_List;
Cref : Node_Id;
Cref2 : Node_Id;
Proc : Entity_Id;
Utyp : Entity_Id;
begin
if Is_Class_Wide_Type (Typ) then
Utyp := Root_Type (Typ);
Cref := Ref;
elsif Is_Concurrent_Type (Typ) then
Utyp := Corresponding_Record_Type (Typ);
Cref := Convert_Concurrent (Ref, Typ);
elsif Is_Private_Type (Typ)
and then Present (Full_View (Typ))
and then Is_Concurrent_Type (Full_View (Typ))
then
Utyp := Corresponding_Record_Type (Full_View (Typ));
Cref := Convert_Concurrent (Ref, Full_View (Typ));
else
Utyp := Typ;
Cref := Ref;
end if;
Utyp := Underlying_Type (Base_Type (Utyp));
Set_Assignment_OK (Cref);
-- Deal with non-tagged derivation of private views
if Is_Untagged_Derivation (Typ) then
Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
Cref := Unchecked_Convert_To (Utyp, Cref);
Set_Assignment_OK (Cref);
-- To prevent problems with UC see 1.156 RH ???
end if;
-- If the underlying_type is a subtype, we are dealing with
-- the completion of a private type. We need to access
-- the base type and generate a conversion to it.
if Utyp /= Base_Type (Utyp) then
pragma Assert (Is_Private_Type (Typ));
Utyp := Base_Type (Utyp);
Cref := Unchecked_Convert_To (Utyp, Cref);
end if;
-- Generate:
-- Deep_Finalize (Ref, With_Detach);
if Has_Controlled_Component (Utyp)
or else Is_Class_Wide_Type (Typ)
then
if Is_Tagged_Type (Utyp) then
Proc := Find_Prim_Op (Utyp, Deep_Name_Of (Finalize_Case));
else
Proc := TSS (Utyp, Deep_Name_Of (Finalize_Case));
end if;
Cref := Convert_View (Proc, Cref);
Append_To (Res,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Proc, Loc),
Parameter_Associations =>
New_List (Cref, With_Detach)));
-- Generate:
-- if With_Detach then
-- Finalize_One (Ref);
-- else
-- Finalize (Ref);
-- end if;
else
Proc := Find_Prim_Op (Utyp, Name_Of (Finalize_Case));
if Chars (With_Detach) = Chars (Standard_True) then
Append_To (Res,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
Parameter_Associations => New_List (
OK_Convert_To (RTE (RE_Finalizable), Cref))));
elsif Chars (With_Detach) = Chars (Standard_False) then
Append_To (Res,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Proc, Loc),
Parameter_Associations =>
New_List (Convert_View (Proc, Cref))));
else
Cref2 := New_Copy_Tree (Cref);
Append_To (Res,
Make_Implicit_If_Statement (Ref,
Condition => With_Detach,
Then_Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
Parameter_Associations => New_List (
OK_Convert_To (RTE (RE_Finalizable), Cref)))),
Else_Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Proc, Loc),
Parameter_Associations =>
New_List (Convert_View (Proc, Cref2))))));
end if;
end if;
-- Treat this as a reference to Finalize if the Finalize routine
-- comes from source. The call is not explicit, but it is near
-- enough, and we won't typically get explicit adjust calls.
if Comes_From_Source (Proc) then
Generate_Reference (Proc, Ref);
end if;
return Res;
end Make_Final_Call;
--------------------
-- Make_Init_Call --
--------------------
function Make_Init_Call
(Ref : Node_Id;
Typ : Entity_Id;
Flist_Ref : Node_Id;
With_Attach : Node_Id)
return List_Id
is
Loc : constant Source_Ptr := Sloc (Ref);
Is_Conc : Boolean;
Res : constant List_Id := New_List;
Proc : Entity_Id;
Utyp : Entity_Id;
Cref : Node_Id;
Cref2 : Node_Id;
Attach : Node_Id := With_Attach;
begin
if Is_Concurrent_Type (Typ) then
Is_Conc := True;
Utyp := Corresponding_Record_Type (Typ);
Cref := Convert_Concurrent (Ref, Typ);
elsif Is_Private_Type (Typ)
and then Present (Full_View (Typ))
and then Is_Concurrent_Type (Underlying_Type (Typ))
then
Is_Conc := True;
Utyp := Corresponding_Record_Type (Underlying_Type (Typ));
Cref := Convert_Concurrent (Ref, Underlying_Type (Typ));
else
Is_Conc := False;
Utyp := Typ;
Cref := Ref;
end if;
Utyp := Underlying_Type (Base_Type (Utyp));
Set_Assignment_OK (Cref);
-- Deal with non-tagged derivation of private views
if Is_Untagged_Derivation (Typ)
and then not Is_Conc
then
Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
Cref := Unchecked_Convert_To (Utyp, Cref);
Set_Assignment_OK (Cref);
-- To prevent problems with UC see 1.156 RH ???
end if;
-- If the underlying_type is a subtype, we are dealing with
-- the completion of a private type. We need to access
-- the base type and generate a conversion to it.
if Utyp /= Base_Type (Utyp) then
pragma Assert (Is_Private_Type (Typ));
Utyp := Base_Type (Utyp);
Cref := Unchecked_Convert_To (Utyp, Cref);
end if;
-- We do not need to attach to one of the Global Final Lists
-- the objects whose type is Finalize_Storage_Only
if Finalize_Storage_Only (Typ)
and then (Global_Flist_Ref (Flist_Ref)
or else Entity (Constant_Value (RTE (RE_Garbage_Collected)))
= Standard_True)
then
Attach := Make_Integer_Literal (Loc, 0);
end if;
-- Generate:
-- Deep_Initialize (Ref, Flist_Ref);
if Has_Controlled_Component (Utyp) then
Proc := TSS (Utyp, Deep_Name_Of (Initialize_Case));
Cref := Convert_View (Proc, Cref, 2);
Append_To (Res,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Proc, Loc),
Parameter_Associations => New_List (
Node1 => Flist_Ref,
Node2 => Cref,
Node3 => Attach)));
-- Generate:
-- Attach_To_Final_List (Ref, Flist_Ref);
-- Initialize (Ref);
else -- Is_Controlled (Utyp)
Proc := Find_Prim_Op (Utyp, Name_Of (Initialize_Case));
Cref := Convert_View (Proc, Cref);
Cref2 := New_Copy_Tree (Cref);
Append_To (Res,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Proc, Loc),
Parameter_Associations => New_List (Cref2)));
Append_To (Res,
Make_Attach_Call (Cref, Flist_Ref, Attach));
-- Treat this as a reference to Initialize if Initialize routine
-- comes from source. The call is not explicit, but it is near
-- enough, and we won't typically get explicit adjust calls.
if Comes_From_Source (Proc) then
Generate_Reference (Proc, Ref);
end if;
end if;
return Res;
end Make_Init_Call;
--------------------------
-- Make_Transient_Block --
--------------------------
-- If finalization is involved, this function just wraps the instruction
-- into a block whose name is the transient block entity, and then
-- Expand_Cleanup_Actions (called on the expansion of the handled
-- sequence of statements will do the necessary expansions for
-- cleanups).
function Make_Transient_Block
(Loc : Source_Ptr;
Action : Node_Id)
return Node_Id
is
Flist : constant Entity_Id := Finalization_Chain_Entity (Current_Scope);
Decls : constant List_Id := New_List;
Par : constant Node_Id := Parent (Action);
Instrs : constant List_Id := New_List (Action);
Blk : Node_Id;
begin
-- Case where only secondary stack use is involved
if Uses_Sec_Stack (Current_Scope)
and then No (Flist)
and then Nkind (Action) /= N_Return_Statement
and then Nkind (Par) /= N_Exception_Handler
then
declare
S : Entity_Id;
K : Entity_Kind;
begin
S := Scope (Current_Scope);
loop
K := Ekind (S);
-- At the outer level, no need to release the sec stack
if S = Standard_Standard then
Set_Uses_Sec_Stack (Current_Scope, False);
exit;
-- In a function, only release the sec stack if the
-- function does not return on the sec stack otherwise
-- the result may be lost. The caller is responsible for
-- releasing.
elsif K = E_Function then
Set_Uses_Sec_Stack (Current_Scope, False);
if not Requires_Transient_Scope (Etype (S)) then
if not Functions_Return_By_DSP_On_Target then
Set_Uses_Sec_Stack (S, True);
Check_Restriction (No_Secondary_Stack, Action);
end if;
end if;
exit;
-- In a loop or entry we should install a block encompassing
-- all the construct. For now just release right away.
elsif K = E_Loop or else K = E_Entry then
exit;
-- In a procedure or a block, we release on exit of the
-- procedure or block. ??? memory leak can be created by
-- recursive calls.
elsif K = E_Procedure
or else K = E_Block
then
if not Functions_Return_By_DSP_On_Target then
Set_Uses_Sec_Stack (S, True);
Check_Restriction (No_Secondary_Stack, Action);
end if;
Set_Uses_Sec_Stack (Current_Scope, False);
exit;
else
S := Scope (S);
end if;
end loop;
end;
end if;
-- Insert actions stuck in the transient scopes as well as all
-- freezing nodes needed by those actions
Insert_Actions_In_Scope_Around (Action);
declare
Last_Inserted : Node_Id := Prev (Action);
begin
if Present (Last_Inserted) then
Freeze_All (First_Entity (Current_Scope), Last_Inserted);
end if;
end;
Blk :=
Make_Block_Statement (Loc,
Identifier => New_Reference_To (Current_Scope, Loc),
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Statements => Instrs),
Has_Created_Identifier => True);
-- When the transient scope was established, we pushed the entry for
-- the transient scope onto the scope stack, so that the scope was
-- active for the installation of finalizable entities etc. Now we
-- must remove this entry, since we have constructed a proper block.
Pop_Scope;
return Blk;
end Make_Transient_Block;
------------------------
-- Node_To_Be_Wrapped --
------------------------
function Node_To_Be_Wrapped return Node_Id is
begin
return Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped;
end Node_To_Be_Wrapped;
----------------------------
-- Set_Node_To_Be_Wrapped --
----------------------------
procedure Set_Node_To_Be_Wrapped (N : Node_Id) is
begin
Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped := N;
end Set_Node_To_Be_Wrapped;
----------------------------------
-- Store_After_Actions_In_Scope --
----------------------------------
procedure Store_After_Actions_In_Scope (L : List_Id) is
SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
begin
if Present (SE.Actions_To_Be_Wrapped_After) then
Insert_List_Before_And_Analyze (
First (SE.Actions_To_Be_Wrapped_After), L);
else
SE.Actions_To_Be_Wrapped_After := L;
if Is_List_Member (SE.Node_To_Be_Wrapped) then
Set_Parent (L, Parent (SE.Node_To_Be_Wrapped));
else
Set_Parent (L, SE.Node_To_Be_Wrapped);
end if;
Analyze_List (L);
end if;
end Store_After_Actions_In_Scope;
-----------------------------------
-- Store_Before_Actions_In_Scope --
-----------------------------------
procedure Store_Before_Actions_In_Scope (L : List_Id) is
SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
begin
if Present (SE.Actions_To_Be_Wrapped_Before) then
Insert_List_After_And_Analyze (
Last (SE.Actions_To_Be_Wrapped_Before), L);
else
SE.Actions_To_Be_Wrapped_Before := L;
if Is_List_Member (SE.Node_To_Be_Wrapped) then
Set_Parent (L, Parent (SE.Node_To_Be_Wrapped));
else
Set_Parent (L, SE.Node_To_Be_Wrapped);
end if;
Analyze_List (L);
end if;
end Store_Before_Actions_In_Scope;
--------------------------------
-- Wrap_Transient_Declaration --
--------------------------------
-- If a transient scope has been established during the processing of the
-- Expression of an Object_Declaration, it is not possible to wrap the
-- declaration into a transient block as usual case, otherwise the object
-- would be itself declared in the wrong scope. Therefore, all entities (if
-- any) defined in the transient block are moved to the proper enclosing
-- scope, furthermore, if they are controlled variables they are finalized
-- right after the declaration. The finalization list of the transient
-- scope is defined as a renaming of the enclosing one so during their
-- initialization they will be attached to the proper finalization
-- list. For instance, the following declaration :
-- X : Typ := F (G (A), G (B));
-- (where G(A) and G(B) return controlled values, expanded as _v1 and _v2)
-- is expanded into :
-- _local_final_list_1 : Finalizable_Ptr;
-- X : Typ := [ complex Expression-Action ];
-- Finalize_One(_v1);
-- Finalize_One (_v2);
procedure Wrap_Transient_Declaration (N : Node_Id) is
S : Entity_Id;
LC : Entity_Id := Empty;
Nodes : List_Id;
Loc : constant Source_Ptr := Sloc (N);
Enclosing_S : Entity_Id;
Uses_SS : Boolean;
Next_N : constant Node_Id := Next (N);
begin
S := Current_Scope;
Enclosing_S := Scope (S);
-- Insert Actions kept in the Scope stack
Insert_Actions_In_Scope_Around (N);
-- If the declaration is consuming some secondary stack, mark the
-- Enclosing scope appropriately.
Uses_SS := Uses_Sec_Stack (S);
Pop_Scope;
-- Create a List controller and rename the final list to be its
-- internal final pointer:
-- Lxxx : Simple_List_Controller;
-- Fxxx : Finalizable_Ptr renames Lxxx.F;
if Present (Finalization_Chain_Entity (S)) then
LC := Make_Defining_Identifier (Loc, New_Internal_Name ('L'));
Nodes := New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => LC,
Object_Definition =>
New_Reference_To (RTE (RE_Simple_List_Controller), Loc)),
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Finalization_Chain_Entity (S),
Subtype_Mark => New_Reference_To (RTE (RE_Finalizable_Ptr), Loc),
Name =>
Make_Selected_Component (Loc,
Prefix => New_Reference_To (LC, Loc),
Selector_Name => Make_Identifier (Loc, Name_F))));
-- Put the declaration at the beginning of the declaration part
-- to make sure it will be before all other actions that have been
-- inserted before N.
Insert_List_Before_And_Analyze (First (List_Containing (N)), Nodes);
-- Generate the Finalization calls by finalizing the list
-- controller right away. It will be re-finalized on scope
-- exit but it doesn't matter. It cannot be done when the
-- call initializes a renaming object though because in this
-- case, the object becomes a pointer to the temporary and thus
-- increases its life span.
if Nkind (N) = N_Object_Renaming_Declaration
and then Controlled_Type (Etype (Defining_Identifier (N)))
then
null;
else
Nodes :=
Make_Final_Call (
Ref => New_Reference_To (LC, Loc),
Typ => Etype (LC),
With_Detach => New_Reference_To (Standard_False, Loc));
if Present (Next_N) then
Insert_List_Before_And_Analyze (Next_N, Nodes);
else
Append_List_To (List_Containing (N), Nodes);
end if;
end if;
end if;
-- Put the local entities back in the enclosing scope, and set the
-- Is_Public flag appropriately.
Transfer_Entities (S, Enclosing_S);
-- Mark the enclosing dynamic scope so that the sec stack will be
-- released upon its exit unless this is a function that returns on
-- the sec stack in which case this will be done by the caller.
if Uses_SS then
S := Enclosing_Dynamic_Scope (S);
if Ekind (S) = E_Function
and then Requires_Transient_Scope (Etype (S))
then
null;
else
Set_Uses_Sec_Stack (S);
Check_Restriction (No_Secondary_Stack, N);
end if;
end if;
end Wrap_Transient_Declaration;
-------------------------------
-- Wrap_Transient_Expression --
-------------------------------
-- Insert actions before <Expression>:
-- (lines marked with <CTRL> are expanded only in presence of Controlled
-- objects needing finalization)
-- _E : Etyp;
-- declare
-- _M : constant Mark_Id := SS_Mark;
-- Local_Final_List : System.FI.Finalizable_Ptr; <CTRL>
-- procedure _Clean is
-- begin
-- Abort_Defer;
-- System.FI.Finalize_List (Local_Final_List); <CTRL>
-- SS_Release (M);
-- Abort_Undefer;
-- end _Clean;
-- begin
-- _E := <Expression>;
-- at end
-- _Clean;
-- end;
-- then expression is replaced by _E
procedure Wrap_Transient_Expression (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
E : constant Entity_Id :=
Make_Defining_Identifier (Loc, New_Internal_Name ('E'));
Etyp : Entity_Id := Etype (N);
begin
Insert_Actions (N, New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => E,
Object_Definition => New_Reference_To (Etyp, Loc)),
Make_Transient_Block (Loc,
Action =>
Make_Assignment_Statement (Loc,
Name => New_Reference_To (E, Loc),
Expression => Relocate_Node (N)))));
Rewrite (N, New_Reference_To (E, Loc));
Analyze_And_Resolve (N, Etyp);
end Wrap_Transient_Expression;
------------------------------
-- Wrap_Transient_Statement --
------------------------------
-- Transform <Instruction> into
-- (lines marked with <CTRL> are expanded only in presence of Controlled
-- objects needing finalization)
-- declare
-- _M : Mark_Id := SS_Mark;
-- Local_Final_List : System.FI.Finalizable_Ptr ; <CTRL>
-- procedure _Clean is
-- begin
-- Abort_Defer;
-- System.FI.Finalize_List (Local_Final_List); <CTRL>
-- SS_Release (_M);
-- Abort_Undefer;
-- end _Clean;
-- begin
-- <Instr uction>;
-- at end
-- _Clean;
-- end;
procedure Wrap_Transient_Statement (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
New_Statement : constant Node_Id := Relocate_Node (N);
begin
Rewrite (N, Make_Transient_Block (Loc, New_Statement));
-- With the scope stack back to normal, we can call analyze on the
-- resulting block. At this point, the transient scope is being
-- treated like a perfectly normal scope, so there is nothing
-- special about it.
-- Note: Wrap_Transient_Statement is called with the node already
-- analyzed (i.e. Analyzed (N) is True). This is important, since
-- otherwise we would get a recursive processing of the node when
-- we do this Analyze call.
Analyze (N);
end Wrap_Transient_Statement;
end Exp_Ch7;