gcc/ada/libgnat/s-sopco4.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --           S Y S T E M . S T R I N G _ O P S _ C O N C A T _ 4            --
   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 --  NOTE: This package is obsolescent. It is no longer used by the compiler
  33 --  which now generates concatenation inline. It is retained only because
  34 --  it may be used during bootstrapping using old versions of the compiler.
  35
  36 pragma Compiler_Unit_Warning;
  37
  38 package body System.String_Ops_Concat_4 is
  39
  40    ------------------
  41    -- Str_Concat_4 --
  42    ------------------
  43
  44    function Str_Concat_4 (S1, S2, S3, S4 : String) return String is
  45    begin
  46       if S1'Length = 0 then
  47          return S2 & S3 & S4;
  48
  49       else
  50          declare
  51             L12 : constant Natural := S1'Length + S2'Length;
  52             L13 : constant Natural := L12 + S3'Length;
  53             L14 : constant Natural := L13 + S4'Length;
  54             R : String (S1'First .. S1'First + L14 - 1);
  55
  56          begin
  57             R (S1'First       .. S1'Last)            := S1;
  58             R (S1'Last + 1    .. S1'First + L12 - 1) := S2;
  59             R (S1'First + L12 .. S1'First + L13 - 1) := S3;
  60             R (S1'First + L13 .. R'Last)             := S4;
  61             return R;
  62          end;
  63       end if;
  64    end Str_Concat_4;
  65
  66 end System.String_Ops_Concat_4;