------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                              P R J . U T I L                             --
--                                                                          --
--                                 S p e c                                  --
--                                                                          --
--                                                                          --
--             Copyright (C) 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. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------
--
--  Utilities when using project files.

with GNAT.OS_Lib; use GNAT.OS_Lib;
with Types;       use Types;

package Prj.Util is

   function Value_Of
     (Variable : Variable_Value;
      Default  : String)
      return     String;
   --  Get the value of a single string variable. If Variable is
   --  Nil_Variable_Value, is a string list or is defaulted, return Default.

   function Value_Of
     (Index    : Name_Id;
      In_Array : Array_Element_Id)
      return     Name_Id;
   --  Get a single string array component.
   --  Returns No_Name if there is no component Index (case sensitive),
   --  if In_Array is null, or if the component is a String list.

   function Value_Of
     (Index    : Name_Id;
      In_Array : Array_Element_Id)
      return     Variable_Value;
   --  Get a string array component (single String or String list).
   --  Returns Nil_Variable_Value if there is no component Index
   --  (case sensitive), or if In_Array is null.

   function Value_Of
     (Name                    : Name_Id;
      Attribute_Or_Array_Name : Name_Id;
      In_Package              : Package_Id)
      return                    Variable_Value;
   --  In a specific package,
   --   - if there exists an array Variable_Or_Array_Name with an index
   --     Name, returns the corresponding component,
   --   - otherwise if there is a attribute Attribute_Or_Array_Name,
   --     returns this attribute,
   --   - otherwise, returns Nil_Variable_Value.
   --  If In_Package is null, returns Nil_Variable_Value.

   function Value_Of
     (Index     : Name_Id;
      In_Array  : Name_Id;
      In_Arrays : Array_Id)
      return      Name_Id;
   --  Get a string array component in an array of an array list.
   --  Returns No_Name if there is no component Index (case sensitive),
   --  if In_Arrays is null, if In_Array is not found in In_Arrays,
   --  or if the component is a String list.

   function Value_Of
     (Name      : Name_Id;
      In_Arrays : Array_Id)
      return      Array_Element_Id;
   --  Returns a specified array in an array list. Returns No_Array_Element
   --  if In_Arrays is null or if Name is not the name of an array in
   --  In_Arrays. The caller must ensure that Name is in lower case.

   function Value_Of
     (Name        : Name_Id;
      In_Packages : Package_Id)
      return        Package_Id;
   --  Returns a specified package in a package list. Returns No_Package
   --  if In_Packages is null or if Name is not the name of a package in
   --  Package_List. The caller must ensure that Name is in lower case.

   function Value_Of
     (Variable_Name : Name_Id;
      In_Variables  : Variable_Id)
      return          Variable_Value;
   --  Returns a specified variable in a variable list. Returns null if
   --  In_Variables is null or if Variable_Name is not the name of a
   --  variable in In_Variables. Caller must ensure that Name is lower case.

   procedure Write_Str
     (S          : String;
      Max_Length : Positive;
      Separator  : Character);
   --  Output string S using Output.Write_Str. If S is too long to fit in
   --  one line of Max_Length, cut it in several lines, using Separator as
   --  the last character of each line, if possible.

   type Text_File is limited private;
   --  Represents a text file. Default is invalid text file.

   function Is_Valid (File : Text_File) return Boolean;
   --  Returns True if File designates an open text file that
   --  has not yet been closed.

   procedure Open (File : out Text_File; Name : String);
   --  Open a text file. If this procedure fails, File is invalid.

   function End_Of_File (File : Text_File) return Boolean;
   --  Returns True if the end of the text file File has been
   --  reached. Fails if File is invalid.

   procedure Get_Line
     (File : Text_File;
      Line : out String;
      Last : out Natural);
   --  Reads a line from an open text file. Fails if File is invalid.

   procedure Close (File : in out Text_File);
   --  Close an open text file. File becomes invalid.
   --  Fails if File is already invalid.

private

   type Text_File_Data is record
      FD                  : File_Descriptor := Invalid_FD;
      Buffer              : String (1 .. 1_000);
      Buffer_Len          : Natural;
      Cursor              : Natural := 0;
      End_Of_File_Reached : Boolean := False;
   end record;

   type Text_File is access Text_File_Data;

end Prj.Util;
