gcc/ada/validsw.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              V A L I D S W                               --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2001-2005, 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 2,  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 COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 --  This unit contains the routines used to handle setting of validity
  28 --  checking options.
  29
  30 package Validsw is
  31
  32    -----------------------------
  33    -- Validity Check Switches --
  34    -----------------------------
  35
  36    --  The following flags determine the specific set of validity checks
  37    --  to be made if validity checking is active (Validity_Checks_On = True)
  38
  39    --  See GNAT users guide for an exact description of each option. The letter
  40    --  given in the comment is the letter used in the -gnatV compiler switch
  41    --  or in the argument of a Validity_Checks pragma to activate the option.
  42    --  The corresponding upper case letter deactivates the option.
  43
  44    Validity_Check_Copies : Boolean := False;
  45    --  Controls the validity checking of copies. If this switch is set to
  46    --  true using -gnatVc, or a 'c' in the argument of a Validity_Checks
  47    --  pragma, then the right side of assignments and also initializing
  48    --  expressions in object declarations are checked for validity.
  49
  50    Validity_Check_Default : Boolean := True;
  51    --  Controls default (reference manual) validity checking. If this switch is
  52    --  set to True using -gnatVd or a 'd' in the argument of a Validity_ Checks
  53    --  pragma (or the initial default value is used, set True), then left side
  54    --  subscripts and case statement arguments are checked for validity. This
  55    --  switch is also set by default if no -gnatV switch is used and no
  56    --  Validity_Checks pragma is processed.
  57
  58    Validity_Check_Floating_Point : Boolean := False;
  59    --  Normally validity checking applies only to discrete values (integer
  60    --  and enumeration types). If this switch is set to True using -gnatVf
  61    --  or an 'f' in the argument of a Validity_Checks pragma, then floating-
  62    --  point values are also checked. The context in which such checks
  63    --  occur depends on other flags, e.g. if Validity_Check_Copies is also
  64    --  set then floating-point values on the right side of an assignment
  65    --  will be validity checked.
  66
  67    Validity_Check_In_Out_Params : Boolean := False;
  68    --  Controls the validity checking of IN OUT parameters. If this switch
  69    --  is set to True using -gnatVm or a 'm' in the argument of a pragma
  70    --  Validity_Checks, then the initial value of all IN OUT parameters
  71    --  will be checked at the point of call of a procecure. Note that the
  72    --  character 'm' here stands for modified (parameters).
  73
  74    Validity_Check_In_Params : Boolean := False;
  75    --  Controls the validity checking of IN parameters. If this switch is
  76    --  set to True using -gnatVm or an 'i' in the argument of a pragma
  77    --  Validity_Checks, then the initial value of all IN parameters
  78    --  will be checked at the point of call of a procecure or function.
  79
  80    Validity_Check_Operands : Boolean := False;
  81    --  Controls validity checking of operands. If this switch is set to
  82    --  True using -gnatVo or an 'o' in the argument of a Validity_Checks
  83    --  pragma, then operands of all predefined operators and attributes
  84    --  will be validity checked.
  85
  86    Validity_Check_Parameters : Boolean := False;
  87    --  This controls validity treatment for parameters within a subprogram.
  88    --  Normally if validity checking is enabled for parameters on a call
  89    --  (Validity_Check_In[_Out]_Params) then an assumption is made that the
  90    --  parameter values are valid on entry and not checked again within a
  91    --  procedure. Setting Validity_Check_Parameters removes this assumption
  92    --  and ensures that no assumptions are made about parameters, so that
  93    --  they will always be checked.
  94
  95    Validity_Check_Returns : Boolean := False;
  96    --  Controls validity checking of returned values. If this switch is set
  97    --  to True using -gnatVr, or an 'r' in the argument of a Validity_Checks
  98    --  pragma, then the expression in a RETURN statement is validity checked.
  99
 100    Validity_Check_Subscripts : Boolean := False;
 101    --  Controls validity checking of subscripts. If this switch is set to
 102    --  True using -gnatVs, or an 's' in the argument of a Validity_Checks
 103    --  pragma, then all subscripts are checked for validity. Note that left
 104    --  side subscript checking is controlled also by Validity_Check_Default.
 105    --  If Validity_Check_Subscripts is True, then all subscripts are checked,
 106    --  otherwise if Validity_Check_Default is True, then left side subscripts
 107    --  are checked, otherwise no subscripts are checked.
 108
 109    Validity_Check_Tests : Boolean := False;
 110    --  Controls validity checking of tests that occur in conditions (i.e. the
 111    --  tests in IF, WHILE, and EXIT statements, and in entry guards). If this
 112    --  switch is set to True using -gnatVt, or a 't' in the argument of a
 113    --  Validity_Checks pragma, then all such conditions are validity checked.
 114
 115    Force_Validity_Checks : Boolean := False;
 116    --  Normally, operands that do not come from source (i.e. cases of expander
 117    --  generated code) are not checked, if this flag is set True, then checking
 118    --  of such operands is forced (if Validity_Check_Operands is set).
 119
 120    -----------------
 121    -- Subprograms --
 122    -----------------
 123
 124    procedure Set_Default_Validity_Check_Options;
 125    --  This procedure is called to set the default validity checking options
 126    --  that apply if no Validity_Check switches or pragma is given.
 127
 128    procedure Set_Validity_Check_Options
 129      (Options  : String;
 130       OK       : out Boolean;
 131       Err_Col  : out Natural);
 132    --  This procedure is called to set the validity check options that
 133    --  correspond to the characters in the given Options string. If
 134    --  all options are valid, then Set_Default_Validity_Check_Options
 135    --  is first called to set the defaults, and then the options in the
 136    --  given string are set in an additive manner. If any invalid character
 137    --  is found, then OK is False on exit, and Err_Col is the index in
 138    --  in options of the bad character. If all options are valid, then
 139    --  OK is True on return, and Err_Col is set to options'Last + 1.
 140
 141    procedure Set_Validity_Check_Options (Options : String);
 142    --  Like the above procedure, except that the call is simply ignored if
 143    --  there are any error conditions, this is for example appopriate for
 144    --  calls where the string is known to be valid, e.g. because it was
 145    --  obtained by Save_Validity_Check_Options.
 146
 147    procedure Reset_Validity_Check_Options;
 148    --  Sets all validity check options to off
 149
 150    subtype Validity_Check_Options is String (1 .. 16);
 151    --  Long enough string to hold all options from Save call below
 152
 153    procedure Save_Validity_Check_Options
 154      (Options : out Validity_Check_Options);
 155    --  Sets Options to represent current selection of options. This
 156    --  set can be restored by first calling Reset_Validity_Check_Options,
 157    --  and then calling Set_Validity_Check_Options with the Options string.
 158
 159 end Validsw;