gcc/ada/libgnat/s-valboo.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                      S Y S T E M . V A L _ B O O L                       --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2023, 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 --  Preconditions in this unit are meant for analysis only, not for run-time
  33 --  checking, so that the expected exceptions are raised. This is enforced by
  34 --  setting the corresponding assertion policy to Ignore. Postconditions and
  35 --  contract cases should not be executed at runtime as well, in order not to
  36 --  slow down the execution of these functions.
  37
  38 pragma Assertion_Policy (Pre            => Ignore,
  39                          Post           => Ignore,
  40                          Contract_Cases => Ignore,
  41                          Ghost          => Ignore);
  42
  43 with System.Val_Spec;
  44
  45 package System.Val_Bool
  46   with SPARK_Mode
  47 is
  48    pragma Preelaborate;
  49
  50    function Value_Boolean (Str : String) return Boolean
  51    with
  52      Pre  => System.Val_Spec.Is_Boolean_Image_Ghost (Str, True)
  53        or else System.Val_Spec.Is_Boolean_Image_Ghost (Str, False),
  54      Post =>
  55        Value_Boolean'Result =
  56          (Str (System.Val_Spec.First_Non_Space_Ghost
  57             (Str, Str'First, Str'Last)) in 't' | 'T');
  58    --  Computes Boolean'Value (Str)
  59
  60 end System.Val_Bool;