249 lines
12 KiB
Ada
249 lines
12 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- E X P _ C H 7 --
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-- --
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-- S p e c --
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-- --
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-- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
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-- for more details. You should have received a copy of the GNU General --
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-- Public License distributed with GNAT; see file COPYING3. If not, go to --
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-- http://www.gnu.org/licenses for a complete copy of the license. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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with Namet; use Namet;
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with Types; use Types;
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package Exp_Ch7 is
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procedure Expand_N_Package_Body (N : Node_Id);
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procedure Expand_N_Package_Declaration (N : Node_Id);
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-----------------------------
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-- Finalization Management --
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-----------------------------
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function In_Finalization_Root (E : Entity_Id) return Boolean;
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-- True if current scope is in package System.Finalization_Root. Used
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-- to avoid certain expansions that would involve circularity in the
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-- Rtsfind mechanism.
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procedure Build_Final_List (N : Node_Id; Typ : Entity_Id);
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-- Build finalization list for anonymous access types, and for access
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-- types that are frozen before their designated types are known to
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-- be controlled.
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procedure Build_Controlling_Procs (Typ : Entity_Id);
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-- Typ is a record, and array type having controlled components.
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-- Create the procedures Deep_Initialize, Deep_Adjust and Deep_Finalize
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-- that take care of finalization management at run-time.
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procedure Build_Late_Proc (Typ : Entity_Id; Nam : Name_Id);
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-- Build one controlling procedure when a late body overrides one of
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-- the controlling operations.
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function Controller_Component (Typ : Entity_Id) return Entity_Id;
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-- Returns the entity of the component whose name is 'Name_uController'
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function CW_Or_Has_Controlled_Part (T : Entity_Id) return Boolean;
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-- True if T is a class-wide type, or if it has controlled parts ("part"
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-- means T or any of its subcomponents). This is the same as
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-- Needs_Finalization, except when pragma Restrictions (No_Finalization)
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-- applies, in which case we know that class-wide objects do not contain
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-- controlled parts.
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procedure Expand_Ctrl_Function_Call (N : Node_Id);
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-- Expand a call to a function returning a controlled value. That is to
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-- say attach the result of the call to the current finalization list,
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-- which is the one of the transient scope created for such constructs.
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function Find_Final_List
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(E : Entity_Id;
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Ref : Node_Id := Empty) return Node_Id;
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-- E is an entity representing a controlled object, a controlled type or a
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-- scope. If Ref is not empty, it is a reference to a controlled record,
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-- the closest Final list is in the controller component of the record
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-- containing Ref, otherwise this function returns a reference to the final
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-- list attached to the closest dynamic scope (which can be E itself),
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-- creating this final list if necessary.
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function Has_New_Controlled_Component (E : Entity_Id) return Boolean;
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-- E is a type entity. Give the same result as Has_Controlled_Component
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-- except for tagged extensions where the result is True only if the
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-- latest extension contains a controlled component.
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function Make_Attach_Call
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(Obj_Ref : Node_Id;
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Flist_Ref : Node_Id;
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With_Attach : Node_Id) return Node_Id;
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-- Attach the referenced object to the referenced Final Chain 'Flist_Ref'
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-- With_Attach is an expression of type Short_Short_Integer which can be
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-- either '0' to signify no attachment, '1' for attachment to a simply
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-- linked list or '2' for attachment to a doubly linked list.
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function Make_Init_Call
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(Ref : Node_Id;
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Typ : Entity_Id;
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Flist_Ref : Node_Id;
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With_Attach : Node_Id) return List_Id;
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-- Ref is an expression (with no-side effect and is not required to have
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-- been previously analyzed) that references the object to be initialized.
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-- Typ is the expected type of Ref, which is either a controlled type
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-- (Is_Controlled) or a type with controlled components (Has_Controlled).
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-- With_Attach is an integer expression which is the attachment level,
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-- see System.Finalization_Implementation.Attach_To_Final_List for the
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-- documentation of Nb_Link.
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--
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-- This function will generate the appropriate calls to make sure that the
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-- objects referenced by Ref are initialized. The generated code is quite
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-- different for an IS_Controlled type or a HAS_Controlled type, but this
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-- is not the problem for the caller, the details are in the body.
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function Make_Adjust_Call
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(Ref : Node_Id;
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Typ : Entity_Id;
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Flist_Ref : Node_Id;
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With_Attach : Node_Id;
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Allocator : Boolean := False) return List_Id;
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-- Ref is an expression (with no-side effect and is not required to have
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-- been previously analyzed) that references the object to be adjusted. Typ
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-- is the expected type of Ref, which is a controlled type (Is_Controlled)
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-- or a type with controlled components (Has_Controlled). With_Attach is an
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-- integer expression giving the attachment level (see documentation of
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-- Attach_To_Final_List.Nb_Link param documentation in s-finimp.ads.
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-- Note: if Typ is Finalize_Storage_Only and the object is at library
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-- level, then With_Attach will be ignored, and a zero link level will be
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-- passed to Attach_To_Final_List.
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--
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-- This function will generate the appropriate calls to make sure that the
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-- objects referenced by Ref are adjusted. The generated code is quite
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-- different depending on the fact the type IS_Controlled or HAS_Controlled
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-- but this is not the problem of the caller, the details are in the body.
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-- The objects must be attached when the adjust takes place after an
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-- initialization expression but not when it takes place after a regular
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-- assignment.
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--
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-- If Allocator is True, we are adjusting a newly-created object. The
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-- existing chaining pointers should not be left unchanged, because they
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-- may come from a bit-for-bit copy of those from an initializing object.
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-- So, when this flag is True, if the chaining pointers should otherwise
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-- be left unset, instead they are reset to null.
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function Make_Final_Call
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(Ref : Node_Id;
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Typ : Entity_Id;
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With_Detach : Node_Id) return List_Id;
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-- Ref is an expression (with no-side effect and is not required to have
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-- been previously analyzed) that references the object to be Finalized.
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-- Typ is the expected type of Ref, which is a controlled type
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-- (Is_Controlled) or a type with controlled components (Has_Controlled).
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-- With_Detach is a boolean expression indicating whether to detach the
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-- controlled object from whatever finalization list it is currently
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-- attached to.
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--
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-- This function will generate the appropriate calls to make sure that the
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-- objects referenced by Ref are finalized. The generated code is quite
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-- different depending on the fact the type IS_Controlled or HAS_Controlled
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-- but this is not the problem of the caller, the details are in the body.
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-- The objects must be detached when finalizing an unchecked deallocated
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-- object but not when finalizing the target of an assignment, it is not
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-- necessary either on scope exit.
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function Make_Handler_For_Ctrl_Operation (Loc : Source_Ptr) return Node_Id;
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-- Generate an implicit exception handler with an 'others' choice,
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-- converting any occurrence to a raise of Program_Error.
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function Needs_Finalization (T : Entity_Id) return Boolean;
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-- True if T potentially needs finalization actions. True if T is
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-- controlled, or has subcomponents. Also True if T is a class-wide type,
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-- because some type extension might add controlled subcomponents, except
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-- that if pragma Restrictions (No_Finalization) applies, this is False for
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-- class-wide types.
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--------------------------------------------
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-- Task and Protected Object finalization --
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--------------------------------------------
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function Cleanup_Array
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(N : Node_Id;
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Obj : Node_Id;
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Typ : Entity_Id) return List_Id;
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-- Generate loops to finalize any tasks or simple protected objects that
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-- are subcomponents of an array.
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function Cleanup_Protected_Object
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(N : Node_Id;
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Ref : Node_Id) return Node_Id;
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-- Generate code to finalize a protected object without entries
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function Cleanup_Record
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(N : Node_Id;
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Obj : Node_Id;
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Typ : Entity_Id) return List_Id;
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-- For each subcomponent of a record that contains tasks or simple
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-- protected objects, generate the appropriate finalization call.
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function Cleanup_Task
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(N : Node_Id;
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Ref : Node_Id) return Node_Id;
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-- Generate code to finalize a task
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function Has_Simple_Protected_Object (T : Entity_Id) return Boolean;
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-- Check whether composite type contains a simple protected component
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function Is_Simple_Protected_Type (T : Entity_Id) return Boolean;
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-- Check whether argument is a protected type without entries. Protected
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-- types with entries are controlled, and their cleanup is handled by the
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-- standard finalization machinery. For simple protected types we generate
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-- inline code to release their locks.
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--------------------------------
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-- Transient Scope Management --
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--------------------------------
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procedure Expand_Cleanup_Actions (N : Node_Id);
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-- Expand the necessary stuff into a scope to enable finalization of local
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-- objects and deallocation of transient data when exiting the scope. N is
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-- a "scope node" that is to say one of the following: N_Block_Statement,
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-- N_Subprogram_Body, N_Task_Body, N_Entry_Body.
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procedure Establish_Transient_Scope (N : Node_Id; Sec_Stack : Boolean);
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-- Push a new transient scope on the scope stack. N is the node responsible
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-- for the need of a transient scope. If Sec_Stack is True then the
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-- secondary stack is brought in, otherwise it isn't.
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function Node_To_Be_Wrapped return Node_Id;
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-- return the node to be wrapped if the current scope is transient
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procedure Store_Before_Actions_In_Scope (L : List_Id);
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-- Append the list L of actions to the end of the before-actions store in
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-- the top of the scope stack
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procedure Store_After_Actions_In_Scope (L : List_Id);
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-- Append the list L of actions to the beginning of the after-actions store
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-- in the top of the scope stack
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procedure Wrap_Transient_Declaration (N : Node_Id);
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-- N is an object declaration. Expand the finalization calls after the
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-- declaration and make the outer scope being the transient one.
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procedure Wrap_Transient_Expression (N : Node_Id);
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-- N is a sub-expression. Expand a transient block around an expression
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procedure Wrap_Transient_Statement (N : Node_Id);
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-- N is a statement. Expand a transient block around an instruction
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end Exp_Ch7;
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