1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                             L I B . S O R T                              --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--          Copyright (C) 1992-2020, Free Software Foundation, Inc.         --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
17-- for  more details.  You should have  received  a copy of the GNU General --
18-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
19-- http://www.gnu.org/licenses for a complete copy of the license.          --
20--                                                                          --
21-- GNAT was originally developed  by the GNAT team at  New York University. --
22-- Extensive contributions were provided by Ada Core Technologies Inc.      --
23--                                                                          --
24------------------------------------------------------------------------------
25
26with GNAT.Heap_Sort_G;
27
28separate (Lib)
29procedure Sort (Tbl : in out Unit_Ref_Table) is
30
31   T : array (0 .. Integer (Tbl'Last - Tbl'First + 1)) of Unit_Number_Type;
32   --  Actual sort is done on this copy of the array with 0's origin
33   --  subscripts. Location 0 is used as a temporary by the sorting algorithm.
34   --  Also the addressing of the table is more efficient with 0's origin,
35   --  even though we have to copy Tbl back and forth.
36
37   function Lt_Uname (C1, C2 : Natural) return Boolean;
38   --  Comparison routine for comparing Unames. Needed by the sorting routine
39
40   procedure Move_Uname (From : Natural; To : Natural);
41   --  Move routine needed by the sorting routine below
42
43   package Sorting is new GNAT.Heap_Sort_G (Move_Uname, Lt_Uname);
44
45   --------------
46   -- Lt_Uname --
47   --------------
48
49   function Lt_Uname (C1, C2 : Natural) return Boolean is
50   begin
51      --  Preprocessing data and definition files are not sorted, they are
52      --  at the bottom of the list. They are recognized because they are
53      --  the only ones without a Unit_Name.
54
55      if Units.Table (T (C1)).Unit_Name = No_Unit_Name then
56         return False;
57
58      elsif Units.Table (T (C2)).Unit_Name = No_Unit_Name then
59         return True;
60
61      else
62         return
63           Uname_Lt
64             (Units.Table (T (C1)).Unit_Name, Units.Table (T (C2)).Unit_Name);
65      end if;
66   end Lt_Uname;
67
68   ----------------
69   -- Move_Uname --
70   ----------------
71
72   procedure Move_Uname (From : Natural; To : Natural) is
73   begin
74      T (To) := T (From);
75   end Move_Uname;
76
77--  Start of processing for Sort
78
79begin
80   if T'Last > 0 then
81      for I in 1 .. T'Last loop
82         T (I) := Tbl (Int (I) - 1 + Tbl'First);
83      end loop;
84
85      Sorting.Sort (T'Last);
86
87   --  Sort is complete, copy result back into place
88
89      for I in 1 .. T'Last loop
90         Tbl (Int (I) - 1 + Tbl'First) := T (I);
91      end loop;
92   end if;
93end Sort;
94