gcc/ada/lib-sort.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             L I B . S O R T                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --                            $Revision: 1.12 $                             --
  10 --                                                                          --
  11 --   Copyright (C) 1992,1993,1994,1995,1996 Free Software Foundation, Inc.  --
  12 --                                                                          --
  13 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  14 -- terms of the  GNU General Public License as published  by the Free Soft- --
  15 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  16 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  17 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  18 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  19 -- for  more details.  You should have  received  a copy of the GNU General --
  20 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  21 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  22 -- MA 02111-1307, USA.                                                      --
  23 --                                                                          --
  24 -- As a special exception,  if other files  instantiate  generics from this --
  25 -- unit, or you link  this unit with other files  to produce an executable, --
  26 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  27 -- covered  by the  GNU  General  Public  License.  This exception does not --
  28 -- however invalidate  any other reasons why  the executable file  might be --
  29 -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
  31 -- GNAT was originally developed  by the GNAT team at  New York University. --
  32 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  33 --                                                                          --
  34 ------------------------------------------------------------------------------
  35
  36 with GNAT.Heap_Sort_A; use GNAT.Heap_Sort_A;
  37
  38 separate (Lib)
  39 procedure Sort (Tbl : in out Unit_Ref_Table) is
  40
  41    T : array (0 .. Integer (Tbl'Last - Tbl'First + 1)) of Unit_Number_Type;
  42    --  Actual sort is done on this copy of the array with 0's origin
  43    --  subscripts. Location 0 is used as a temporary by the sorting algorithm.
  44    --  Also the addressing of the table is more efficient with 0's origin,
  45    --  even though we have to copy Tbl back and forth.
  46
  47    function Lt_Uname (C1, C2 : Natural) return Boolean;
  48    --  Comparison routine for comparing Unames. Needed by the sorting routine.
  49
  50    procedure Move_Uname (From : Natural; To : Natural);
  51    --  Move routine needed by the sorting routine below.
  52
  53    --------------
  54    -- Lt_Uname --
  55    --------------
  56
  57    function Lt_Uname (C1, C2 : Natural) return Boolean is
  58    begin
  59       return
  60         Uname_Lt
  61           (Units.Table (T (C1)).Unit_Name, Units.Table (T (C2)).Unit_Name);
  62    end Lt_Uname;
  63
  64    ----------------
  65    -- Move_Uname --
  66    ----------------
  67
  68    procedure Move_Uname (From : Natural; To : Natural) is
  69    begin
  70       T (To) := T (From);
  71    end Move_Uname;
  72
  73 --  Start of processing for Sort
  74
  75 begin
  76    if T'Last > 0 then
  77       for I in 1 .. T'Last loop
  78          T (I) := Tbl (Int (I) - 1 + Tbl'First);
  79       end loop;
  80
  81       Sort (T'Last,
  82         Move_Uname'Unrestricted_Access, Lt_Uname'Unrestricted_Access);
  83
  84    --  Sort is complete, copy result back into place
  85
  86       for I in 1 .. T'Last loop
  87          Tbl (Int (I) - 1 + Tbl'First) := T (I);
  88       end loop;
  89    end if;
  90 end Sort;