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--                                                                          --

--                         GNAT COMPILER COMPONENTS                         --

--                                                                          --

--                              V A L I D S W                               --

--                                                                          --

--                                 S p e c                                  --

--                                                                          --

--          Copyright (C) 2001-2008, Free Software Foundation, Inc.         --

--                                                                          --

-- GNAT is free software;  you can  redistribute it  and/or modify it under --

-- terms of the  GNU General Public License as published  by the Free Soft- --

-- ware  Foundation;  either version 3,  or (at your option) any later ver- --

-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --

-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --

-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --

-- for  more details.  You should have  received  a copy of the GNU General --

-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --

-- http://www.gnu.org/licenses for a complete copy of the license.          --

--                                                                          --

-- GNAT was originally developed  by the GNAT team at  New York University. --

-- Extensive contributions were provided by Ada Core Technologies Inc.      --

--                                                                          --

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--  This unit contains the routines used to handle setting of validity

--  checking options.

package Validsw is

   -----------------------------

   -- Validity Check Switches --

   -----------------------------

   --  The following flags determine the specific set of validity checks

   --  to be made if validity checking is active (Validity_Checks_On = True)

   --  See GNAT users guide for an exact description of each option. The letter

   --  given in the comment is the letter used in the -gnatV compiler switch

   --  or in the argument of a Validity_Checks pragma to activate the option.

   --  The corresponding upper case letter deactivates the option.

   Validity_Check_Copies : Boolean := False;

   --  Controls the validity checking of copies. If this switch is set to

   --  true using -gnatVc, or a 'c' in the argument of a Validity_Checks

   --  pragma, then the right side of assignments and also initializing

   --  expressions in object declarations are checked for validity.

   Validity_Check_Components : Boolean := False;

   --  Controls validity checking for assignment to elementary components of

   --  records. If this switch is set true using -gnatVe, or an 'e' in the

   --  argument of Validity_Checks pragma, then the right hand of an assignment

   --  to such a component is checked for validity.

   Validity_Check_Default : Boolean := True;

   --  Controls default (reference manual) validity checking. If this switch is

   --  set to True using -gnatVd or a 'd' in the argument of a Validity_ Checks

   --  pragma (or the initial default value is used, set True), then left side

   --  subscripts and case statement arguments are checked for validity. This

   --  switch is also set by default if no -gnatV switch is used and no

   --  Validity_Checks pragma is processed.

   Validity_Check_Floating_Point : Boolean := False;

   --  Normally validity checking applies only to discrete values (integer

   --  and enumeration types). If this switch is set to True using -gnatVf

   --  or an 'f' in the argument of a Validity_Checks pragma, then floating-

   --  point values are also checked. The context in which such checks

   --  occur depends on other flags, e.g. if Validity_Check_Copies is also

   --  set then floating-point values on the right side of an assignment

   --  will be validity checked.

   Validity_Check_In_Out_Params : Boolean := False;

   --  Controls the validity checking of IN OUT parameters. If this switch

   --  is set to True using -gnatVm or a 'm' in the argument of a pragma

   --  Validity_Checks, then the initial value of all IN OUT parameters

   --  will be checked at the point of call of a procedure. Note that the

   --  character 'm' here stands for modified (parameters).

   Validity_Check_In_Params : Boolean := False;

   --  Controls the validity checking of IN parameters. If this switch is

   --  set to True using -gnatVm or an 'i' in the argument of a pragma

   --  Validity_Checks, then the initial value of all IN parameters

   --  will be checked at the point of call of a procedure or function.

   Validity_Check_Operands : Boolean := False;

   --  Controls validity checking of operands. If this switch is set to

   --  True using -gnatVo or an 'o' in the argument of a Validity_Checks

   --  pragma, then operands of all predefined operators and attributes

   --  will be validity checked.

   Validity_Check_Parameters : Boolean := False;

   --  This controls validity treatment for parameters within a subprogram.

   --  Normally if validity checking is enabled for parameters on a call

   --  (Validity_Check_In[_Out]_Params) then an assumption is made that the

   --  parameter values are valid on entry and not checked again within a

   --  procedure. Setting Validity_Check_Parameters removes this assumption

   --  and ensures that no assumptions are made about parameters, so that

   --  they will always be checked.

   Validity_Check_Returns : Boolean := False;

   --  Controls validity checking of returned values. If this switch is set

   --  to True using -gnatVr, or an 'r' in the argument of a Validity_Checks

   --  pragma, then the expression in a RETURN statement is validity checked.

   Validity_Check_Subscripts : Boolean := False;

   --  Controls validity checking of subscripts. If this switch is set to

   --  True using -gnatVs, or an 's' in the argument of a Validity_Checks

   --  pragma, then all subscripts are checked for validity. Note that left

   --  side subscript checking is controlled also by Validity_Check_Default.

   --  If Validity_Check_Subscripts is True, then all subscripts are checked,

   --  otherwise if Validity_Check_Default is True, then left side subscripts

   --  are checked, otherwise no subscripts are checked.

   Validity_Check_Tests : Boolean := False;

   --  Controls validity checking of tests that occur in conditions (i.e. the

   --  tests in IF, WHILE, and EXIT statements, and in entry guards). If this

   --  switch is set to True using -gnatVt, or a 't' in the argument of a

   --  Validity_Checks pragma, then all such conditions are validity checked.

   Force_Validity_Checks : Boolean := False;

   --  Normally, operands that do not come from source (i.e. cases of expander

   --  generated code) are not checked, if this flag is set True, then checking

   --  of such operands is forced (if Validity_Check_Operands is set).

   -----------------

   -- Subprograms --

   -----------------

   procedure Set_Default_Validity_Check_Options;

   --  This procedure is called to set the default validity checking options

   --  that apply if no Validity_Check switches or pragma is given.

   procedure Set_Validity_Check_Options

     (Options  : String;

      OK       : out Boolean;

      Err_Col  : out Natural);

   --  This procedure is called to set the validity check options that

   --  correspond to the characters in the given Options string. If

   --  all options are valid, then Set_Default_Validity_Check_Options

   --  is first called to set the defaults, and then the options in the

   --  given string are set in an additive manner. If any invalid character

   --  is found, then OK is False on exit, and Err_Col is the index in

   --  in options of the bad character. If all options are valid, then

   --  OK is True on return, and Err_Col is set to options'Last + 1.

   procedure Set_Validity_Check_Options (Options : String);

   --  Like the above procedure, except that the call is simply ignored if

   --  there are any error conditions, this is for example appropriate for

   --  calls where the string is known to be valid, e.g. because it was

   --  obtained by Save_Validity_Check_Options.

   procedure Reset_Validity_Check_Options;

   --  Sets all validity check options to off

   subtype Validity_Check_Options is String (1 .. 16);

   --  Long enough string to hold all options from Save call below

   procedure Save_Validity_Check_Options

     (Options : out Validity_Check_Options);

   --  Sets Options to represent current selection of options. This

   --  set can be restored by first calling Reset_Validity_Check_Options,

   --  and then calling Set_Validity_Check_Options with the Options string.

end Validsw;