gcc/ada/libgnat/s-widenu.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                      S Y S T E M . W I D _ E N U M                       --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2017, 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.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 with Ada.Unchecked_Conversion;
  33
  34 package body System.Wid_Enum is
  35
  36    -------------------------
  37    -- Width_Enumeration_8 --
  38    -------------------------
  39
  40    function Width_Enumeration_8
  41      (Names   : String;
  42       Indexes : System.Address;
  43       Lo, Hi  : Natural)
  44       return    Natural
  45    is
  46       pragma Warnings (Off, Names);
  47
  48       W : Natural;
  49
  50       type Natural_8 is range 0 .. 2 ** 7 - 1;
  51       type Index_Table is array (Natural) of Natural_8;
  52       type Index_Table_Ptr is access Index_Table;
  53
  54       function To_Index_Table_Ptr is
  55         new Ada.Unchecked_Conversion (System.Address, Index_Table_Ptr);
  56
  57       IndexesT : constant Index_Table_Ptr := To_Index_Table_Ptr (Indexes);
  58
  59    begin
  60       W := 0;
  61
  62       for J in Lo .. Hi loop
  63          W := Natural'Max (W, Natural (IndexesT (J + 1) - IndexesT (J)));
  64       end loop;
  65
  66       return W;
  67    end Width_Enumeration_8;
  68
  69    --------------------------
  70    -- Width_Enumeration_16 --
  71    --------------------------
  72
  73    function Width_Enumeration_16
  74      (Names   : String;
  75       Indexes : System.Address;
  76       Lo, Hi  : Natural)
  77       return    Natural
  78    is
  79       pragma Warnings (Off, Names);
  80
  81       W : Natural;
  82
  83       type Natural_16 is range 0 .. 2 ** 15 - 1;
  84       type Index_Table is array (Natural) of Natural_16;
  85       type Index_Table_Ptr is access Index_Table;
  86
  87       function To_Index_Table_Ptr is
  88         new Ada.Unchecked_Conversion (System.Address, Index_Table_Ptr);
  89
  90       IndexesT : constant Index_Table_Ptr := To_Index_Table_Ptr (Indexes);
  91
  92    begin
  93       W := 0;
  94
  95       for J in Lo .. Hi loop
  96          W := Natural'Max (W, Natural (IndexesT (J + 1) - IndexesT (J)));
  97       end loop;
  98
  99       return W;
 100    end Width_Enumeration_16;
 101
 102    --------------------------
 103    -- Width_Enumeration_32 --
 104    --------------------------
 105
 106    function Width_Enumeration_32
 107      (Names   : String;
 108       Indexes : System.Address;
 109       Lo, Hi  : Natural)
 110       return    Natural
 111    is
 112       pragma Warnings (Off, Names);
 113
 114       W : Natural;
 115
 116       type Natural_32 is range 0 .. 2 ** 31 - 1;
 117       type Index_Table is array (Natural) of Natural_32;
 118       type Index_Table_Ptr is access Index_Table;
 119
 120       function To_Index_Table_Ptr is
 121         new Ada.Unchecked_Conversion (System.Address, Index_Table_Ptr);
 122
 123       IndexesT : constant Index_Table_Ptr := To_Index_Table_Ptr (Indexes);
 124
 125    begin
 126       W := 0;
 127
 128       for J in Lo .. Hi loop
 129          W := Natural'Max (W, Natural (IndexesT (J + 1) - IndexesT (J)));
 130       end loop;
 131
 132       return W;
 133    end Width_Enumeration_32;
 134
 135 end System.Wid_Enum;