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diff --git a/gcc/ada/elists.ads b/gcc/ada/elists.ads new file mode 100644 index 000000000..0e9a2a2f3 --- /dev/null +++ b/gcc/ada/elists.ads @@ -0,0 +1,176 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- E L I S T S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides facilities for manipulating lists of nodes (see +-- package Atree for format and implementation of tree nodes). Separate list +-- elements are allocated to represent elements of these lists, so it is +-- possible for a given node to be on more than one element list at a time. +-- See also package Nlists, which provides another form that is threaded +-- through the nodes themselves (using the Link field), which is more time +-- and space efficient, but a node can be only one such list. + +with Types; use Types; +with System; + +package Elists is + + -- An element list is represented by a header that is allocated in the + -- Elist header table. This header contains pointers to the first and + -- last elements in the list, or to No_Elmt if the list is empty. + + -- The elements in the list each contain a pointer to the next element + -- and a pointer to the referenced node. Putting a node into an element + -- list causes no change at all to the node itself, so a node may be + -- included in multiple element lists, and the nodes thus included may + -- or may not be elements of node lists (see package Nlists). + + procedure Initialize; + -- Initialize allocation of element list tables. Called at the start of + -- compiling each new main source file. Note that Initialize must not be + -- called if Tree_Read is used. + + procedure Lock; + -- Lock tables used for element lists before calling backend + + procedure Unlock; + -- Unlock list tables, in cases where the back end needs to modify them + + procedure Tree_Read; + -- Initializes internal tables from current tree file using the relevant + -- Table.Tree_Read routines. Note that Initialize should not be called if + -- Tree_Read is used. Tree_Read includes all necessary initialization. + + procedure Tree_Write; + -- Writes out internal tables to current tree file using the relevant + -- Table.Tree_Write routines. + + function Last_Elist_Id return Elist_Id; + -- Returns Id of last allocated element list header + + function Elists_Address return System.Address; + -- Return address of Elists table (used in Back_End for Gigi call) + + function Num_Elists return Nat; + -- Number of currently allocated element lists + + function Last_Elmt_Id return Elmt_Id; + -- Returns Id of last allocated list element + + function Elmts_Address return System.Address; + -- Return address of Elmts table (used in Back_End for Gigi call) + + function Node (Elmt : Elmt_Id) return Node_Or_Entity_Id; + pragma Inline (Node); + -- Returns the value of a given list element. Returns Empty if Elmt + -- is set to No_Elmt. + + function New_Elmt_List return Elist_Id; + -- Creates a new empty element list. Typically this is used to initialize + -- a field in some other node which points to an element list where the + -- list is then subsequently filled in using Append calls. + + function First_Elmt (List : Elist_Id) return Elmt_Id; + pragma Inline (First_Elmt); + -- Obtains the first element of the given element list or, if the list has + -- no items, then No_Elmt is returned. + + function Last_Elmt (List : Elist_Id) return Elmt_Id; + pragma Inline (Last_Elmt); + -- Obtains the last element of the given element list or, if the list has + -- no items, then No_Elmt is returned. + + function Next_Elmt (Elmt : Elmt_Id) return Elmt_Id; + pragma Inline (Next_Elmt); + -- This function returns the next element on an element list. The argument + -- must be a list element other than No_Elmt. Returns No_Elmt if the given + -- element is the last element of the list. + + procedure Next_Elmt (Elmt : in out Elmt_Id); + pragma Inline (Next_Elmt); + -- Next_Elmt (Elmt) is equivalent to Elmt := Next_Elmt (Elmt) + + function Is_Empty_Elmt_List (List : Elist_Id) return Boolean; + pragma Inline (Is_Empty_Elmt_List); + -- This function determines if a given tree id references an element list + -- that contains no items. + + procedure Append_Elmt (N : Node_Or_Entity_Id; To : Elist_Id); + -- Appends N at the end of To, allocating a new element. N must be a + -- non-empty node or entity Id, and To must be an Elist (not No_Elist). + + procedure Append_Unique_Elmt (N : Node_Or_Entity_Id; To : Elist_Id); + -- Like Append_Elmt, except that a check is made to see if To already + -- contains N and if so the call has no effect. + + procedure Prepend_Elmt (N : Node_Or_Entity_Id; To : Elist_Id); + -- Appends N at the beginning of To, allocating a new element + + procedure Insert_Elmt_After (N : Node_Or_Entity_Id; Elmt : Elmt_Id); + -- Add a new element (N) right after the pre-existing element Elmt + -- It is invalid to call this subprogram with Elmt = No_Elmt. + + procedure Replace_Elmt (Elmt : Elmt_Id; New_Node : Node_Or_Entity_Id); + pragma Inline (Replace_Elmt); + -- Causes the given element of the list to refer to New_Node, the node + -- which was previously referred to by Elmt is effectively removed from + -- the list and replaced by New_Node. + + procedure Remove_Elmt (List : Elist_Id; Elmt : Elmt_Id); + -- Removes Elmt from the given list. The node itself is not affected, + -- but the space used by the list element may be (but is not required + -- to be) freed for reuse in a subsequent Append_Elmt call. + + procedure Remove_Last_Elmt (List : Elist_Id); + -- Removes the last element of the given list. The node itself is not + -- affected, but the space used by the list element may be (but is not + -- required to be) freed for reuse in a subsequent Append_Elmt call. + + function No (List : Elist_Id) return Boolean; + pragma Inline (No); + -- Tests given Id for equality with No_Elist. This allows notations like + -- "if No (Statements)" as opposed to "if Statements = No_Elist". + + function Present (List : Elist_Id) return Boolean; + pragma Inline (Present); + -- Tests given Id for inequality with No_Elist. This allows notations like + -- "if Present (Statements)" as opposed to "if Statements /= No_Elist". + + function No (Elmt : Elmt_Id) return Boolean; + pragma Inline (No); + -- Tests given Id for equality with No_Elmt. This allows notations like + -- "if No (Operation)" as opposed to "if Operation = No_Elmt". + + function Present (Elmt : Elmt_Id) return Boolean; + pragma Inline (Present); + -- Tests given Id for inequality with No_Elmt. This allows notations like + -- "if Present (Operation)" as opposed to "if Operation /= No_Elmt". + +end Elists; |