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------------------------------------------------------------------------------
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-- GNAT COMPILER COMPONENTS --
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-- $Revision: 1.31 $ --
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-- Copyright (C) 1992-2000 Free Software Foundation, Inc. --
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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 2, 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 COPYING. If not, write --
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-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
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-- MA 02111-1307, USA. --
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-- As a special exception, if other files instantiate generics from this --
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-- unit, or you link this unit with other files to produce an executable, --
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-- this unit does not by itself cause the resulting executable to be --
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-- covered by the GNU General Public License. This exception does not --
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-- however invalidate any other reasons why the executable file might be --
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-- covered by the GNU Public License. --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
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------------------------------------------------------------------------------
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-- This package provides facilities for manipulating lists of nodes (see
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-- package Atree for format and implementation of tree nodes). The Link field
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-- of the nodes is used as the forward pointer for these lists. See also
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-- package Elists which provides another form of lists that are not threaded
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-- through the nodes (and therefore allow nodes to be on multiple lists).
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with Types; use Types;
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-- A node list is a list of nodes in a special format that means that
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-- nodes can be on at most one such list. For each node list, a list
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-- header is allocated in the lists table, and a List_Id value references
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-- this header, which may be used to access the nodes in the list using
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-- the set of routines that define this interface.
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-- Note: node lists can contain either nodes or entities (extended nodes)
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-- or a mixture of nodes and extended nodes.
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function Last_List_Id return List_Id;
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pragma Inline (Last_List_Id);
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-- Returns Id of last allocated list header
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function Lists_Address return System.Address;
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pragma Inline (Lists_Address);
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-- Return address of Lists table (used in Back_End for Gigi call)
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function Num_Lists return Nat;
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pragma Inline (Num_Lists);
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-- Number of currently allocated lists
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function New_List return List_Id;
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-- Creates a new empty node list. Typically this is used to initialize
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-- a field in some other node which points to a node list where the list
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-- is then subsequently filled in using Append calls.
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function Empty_List return List_Id renames New_List;
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-- Used in contexts where an empty list (as opposed to an initially empty
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-- list to be filled in) is required.
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function New_List (Node : Node_Id) return List_Id;
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-- Build a new list initially containing the given node
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function New_List (Node1, Node2 : Node_Id) return List_Id;
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-- Build a new list initially containing the two given nodes
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function New_List (Node1, Node2, Node3 : Node_Id) return List_Id;
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-- Build a new list initially containing the three given nodes
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function New_List (Node1, Node2, Node3, Node4 : Node_Id) return List_Id;
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-- Build a new list initially containing the four given nodes
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-- Build a new list initially containing the five given nodes
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-- Build a new list initially containing the five given nodes
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function New_Copy_List (List : List_Id) return List_Id;
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-- Creates a new list containing copies (made with Atree.New_Copy) of every
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-- node in the original list. If the argument is No_List, then the returned
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-- result is No_List. If the argument is an empty list, then the returned
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-- result is a new empty list.
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function New_Copy_List_Original (List : List_Id) return List_Id;
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-- Same as New_Copy_List but copies only nodes coming from source
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function New_Copy_List_Tree (List : List_Id) return List_Id;
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-- Similar to New_Copy_List, except that the copies are done using the
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-- Atree.New_Copy_Tree function, which means that a full recursive copy
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-- of the subtrees in the list is performed, setting proper parents. As
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-- for New_Copy_Tree, it is illegal to attempt to copy extended nodes
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-- (entities) either directly or indirectly using this function.
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function First (List : List_Id) return Node_Id;
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pragma Inline (First);
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-- Obtains the first element of the given node list or, if the node list
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-- has no items or is equal to No_List, then Empty is returned.
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function First_Non_Pragma (List : List_Id) return Node_Id;
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-- Used when dealing with a list that can contain pragmas to skip past
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-- any initial pragmas and return the first element that is not a pragma.
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-- If the list is empty, or if it contains only pragmas, then Empty is
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-- returned. It is an error to call First_Non_Pragma with a Node_Id value
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-- or No_List (No_List is not considered to be the same as an empty list).
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-- This function also skips N_Null nodes which can result from rewriting
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-- unrecognized or incorrrect pragmas.
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function Last (List : List_Id) return Node_Id;
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pragma Inline (Last);
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-- Obtains the last element of the given node list or, if the node list
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-- has no items, then Empty is returned. It is an error to call Last with
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-- a Node_Id or No_List. (No_List is not considered to be the same as an
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function Last_Non_Pragma (List : List_Id) return Node_Id;
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-- Obtains the last element of a given node list that is not a pragma.
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-- If the list is empty, or if it contains only pragmas, then Empty is
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-- returned. It is an error to call Last_Non_Pragma with a Node_Id or
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-- No_List. (No_List is not considered to be the same as an empty list).
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function List_Length (List : List_Id) return Nat;
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pragma Inline (List_Length);
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-- Returns number of items in the given list. It is an error to call
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-- this function with No_List (No_List is not considered to be the same
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-- as an empty list).
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function Next (Node : Node_Id) return Node_Id;
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pragma Inline (Next);
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-- This function returns the next node on a node list, or Empty if Node is
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-- the last element of the node list. The argument must be a member of a
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procedure Next (Node : in out Node_Id);
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pragma Inline (Next);
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-- Equivalent to Node := Next (Node);
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function Next_Non_Pragma (Node : Node_Id) return Node_Id;
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-- This function returns the next node on a node list, skipping past any
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-- pragmas, or Empty if there is no non-pragma entry left. The argument
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-- must be a member of a node list. This function also skips N_Null nodes
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-- which can result from rewriting unrecognized or incorrect pragmas.
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procedure Next_Non_Pragma (Node : in out Node_Id);
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pragma Inline (Next_Non_Pragma);
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-- Equivalent to Node := Next_Non_Pragma (Node);
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function Prev (Node : Node_Id) return Node_Id;
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pragma Inline (Prev);
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-- This function returns the previous node on a node list list, or Empty if
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-- Node is the first element of the node list. The argument must be a
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-- member of a node list. Note that the implementation does not maintain
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-- back pointers, so this function potentially requires traversal of the
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-- entire list, or more accurately of the part of the list preceding Node.
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function Pick (List : List_Id; Index : Pos) return Node_Id;
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-- Given a list, picks out the Index'th entry (1 = first entry). The
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-- caller must ensure that Index is in range.
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procedure Prev (Node : in out Node_Id);
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pragma Inline (Prev);
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-- Equivalent to Node := Prev (Node);
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function Prev_Non_Pragma (Node : Node_Id) return Node_Id;
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pragma Inline (Prev_Non_Pragma);
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-- This function returns the previous node on a node list, skipping any
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-- pragmas. If Node is the first element of the list, or if the only
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-- elements preceding it are pragmas, then Empty is returned. The
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-- argument must be a member of a node list. Like Prev, this function
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-- may require expensive traversal of the head section of the list.
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procedure Prev_Non_Pragma (Node : in out Node_Id);
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pragma Inline (Prev_Non_Pragma);
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-- Equivalent to Node := Prev_Non_Pragma (Node);
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function Is_Empty_List (List : List_Id) return Boolean;
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pragma Inline (Is_Empty_List);
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-- This function determines if a given list id references a node list that
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-- contains no items. No_List is a not a legitimate argument.
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function Is_Non_Empty_List (List : List_Id) return Boolean;
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pragma Inline (Is_Non_Empty_List);
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-- This function determines if a given list id references a node list that
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-- contains at least one item. No_List as an argument returns False.
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function Is_List_Member (Node : Node_Id) return Boolean;
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pragma Inline (Is_List_Member);
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-- This function determines if a given node is a member of a node list.
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-- It is an error for Node to be Empty, or to be a node list.
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function List_Containing (Node : Node_Id) return List_Id;
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pragma Inline (List_Containing);
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-- This function provides a pointer to the node list containing Node.
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-- Node must be a member of a node list.
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procedure Append (Node : Node_Id; To : List_Id);
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-- Appends Node at the end of node list To. Node must be a non-empty node
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-- that is not already a member of a node list, and To must be a
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-- node list. An attempt to append an error node is ignored without
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-- complaint and the list is unchanged.
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procedure Append_To (To : List_Id; Node : Node_Id);
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pragma Inline (Append_To);
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-- Like Append, but arguments are the other way round
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procedure Append_List (List : List_Id; To : List_Id);
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-- Appends node list List to the end of node list To. On return,
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-- List is reset to be empty.
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procedure Append_List_To (To : List_Id; List : List_Id);
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pragma Inline (Append_List_To);
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-- Like Append_List, but arguments are the other way round
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procedure Insert_After (After : Node_Id; Node : Node_Id);
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-- Insert Node, which must be a non-empty node that is not already a
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-- member of a node list, immediately past node After, which must be a
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-- node that is currently a member of a node list. An attempt to insert
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-- an error node is ignored without complaint (and the list is unchanged).
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procedure Insert_List_After (After : Node_Id; List : List_Id);
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-- Inserts the entire contents of node list List immediately after node
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-- After, which must be a member of a node list. On return, the node list
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-- List is reset to be the empty node list.
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procedure Insert_Before (Before : Node_Id; Node : Node_Id);
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-- Insert Node, which must be a non-empty node that is not already a
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-- member of a node list, immediately before Before, which must be a node
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-- that is currently a member of a node list. An attempt to insert an
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-- error node is ignored without complaint (and the list is unchanged).
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procedure Insert_List_Before (Before : Node_Id; List : List_Id);
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-- Inserts the entire contents of node list List immediately before node
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-- Before, which must be a member of a node list. On return, the node list
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-- List is reset to be the empty node list.
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procedure Prepend (Node : Node_Id; To : List_Id);
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pragma Inline (Prepend);
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-- Prepends Node at the start of node list To. Node must be a non-empty
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-- node that is not already a member of a node list, and To must be a
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-- node list. An attempt to prepend an error node is ignored without
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-- complaint and the list is unchanged.
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procedure Prepend_To (To : List_Id; Node : Node_Id);
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pragma Inline (Prepend_To);
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-- Like Prepend, but arguments are the other way round
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procedure Remove (Node : Node_Id);
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-- Removes Node, which must be a node that is a member of a node list,
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-- from this node list. The contents of Node are not otherwise affected.
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function Remove_Head (List : List_Id) return Node_Id;
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-- Removes the head element of a node list, and returns the node (whose
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-- contents are not otherwise affected) as the result. If the node list
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-- is empty, then Empty is returned.
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function Remove_Next (Node : Node_Id) return Node_Id;
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pragma Inline (Remove_Next);
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-- Removes the item immediately following the given node, and returns it
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-- as the result. If Node is the last element of the list, then Empty is
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-- returned. Node must be a member of a list. Unlike Remove, Remove_Next
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-- is fast and does not involve any list traversal.
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procedure Initialize;
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-- Called at the start of compilation of each new main source file to
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-- initialize the allocation of the list table. Note that Initialize
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-- must not be called if Tree_Read is used.
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-- Called to lock tables before back end is called
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-- Initializes internal tables from current tree file using Tree_Read.
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-- Note that Initialize should not be called if Tree_Read is used.
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-- Tree_Read includes all necessary initialization.
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procedure Tree_Write;
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-- Writes out internal tables to current tree file using Tree_Write
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function Parent (List : List_Id) return Node_Id;
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pragma Inline (Parent);
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-- Node lists may have a parent in the same way as a node. The function
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-- accesses the Parent value, which is either Empty when a list header
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-- is first created, or the value that has been set by Set_Parent.
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procedure Set_Parent (List : List_Id; Node : Node_Id);
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pragma Inline (Set_Parent);
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-- Sets the parent field of the given list to reference the given node
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function No (List : List_Id) return Boolean;
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-- Tests given Id for equality with No_List. This allows notations like
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-- "if No (Statements)" as opposed to "if Statements = No_List".
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function Present (List : List_Id) return Boolean;
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pragma Inline (Present);
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-- Tests given Id for inequality with No_List. This allows notations like
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-- "if Present (Statements)" as opposed to "if Statements /= No_List".
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procedure Allocate_List_Tables (N : Node_Id);
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-- Called when nodes table is expanded to include node N. This call
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-- makes sure that list structures internal to Nlists are adjusted
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-- apropriately to reflect this increase in the size of the nodes table.
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function Next_Node_Address return System.Address;
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function Prev_Node_Address return System.Address;
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-- These functions return the addresses of the Next_Node and Prev_Node
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-- tables (used in Back_End for Gigi).
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procedure Delete_List (L : List_Id);
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-- Removes all elements of the given list, and calls Delete_Tree on each
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function p (U : Union_Id) return Node_Id;
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-- This function is intended for use from the debugger, it determines
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-- whether U is a Node_Id or List_Id, and calls the appropriate Parent
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-- function and returns the parent Node in either case. This is shorter
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-- to type, and avoids the overloading problem of using Parent. It
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-- should NEVER be used except from the debugger. If p is called with
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-- other than a node or list id value, it returns 99_999_999.
added
removed
gnat/nlists.ads
