File : 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) 2001-2012, 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. 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 COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
25
26 -- This unit contains the routines used to handle setting of validity
27 -- checking options.
28
29 package Validsw is
30
31 -----------------------------
32 -- Validity Check Switches --
33 -----------------------------
34
35 -- The following flags determine the specific set of validity checks
36 -- to be made if validity checking is active (Validity_Checks_On = True)
37
38 -- See GNAT users guide for an exact description of each option. The letter
39 -- given in the comment is the letter used in the -gnatV compiler switch
40 -- or in the argument of a Validity_Checks pragma to activate the option.
41 -- The corresponding upper case letter deactivates the option.
42
43 Validity_Check_Copies : Boolean := False;
44 -- Controls the validity checking of copies. If this switch is set to
45 -- true using -gnatVc, or a 'c' in the argument of a Validity_Checks
46 -- pragma, then the right side of assignments and also initializing
47 -- expressions in object declarations are checked for validity.
48
49 Validity_Check_Components : Boolean := False;
50 -- Controls validity checking for assignment to elementary components of
51 -- records. If this switch is set true using -gnatVe, or an 'e' in the
52 -- argument of Validity_Checks pragma, then the right hand of an assignment
53 -- to such a component is checked for validity.
54
55 Validity_Check_Default : Boolean := True;
56 -- Controls default (reference manual) validity checking. If this switch is
57 -- set to True using -gnatVd or a 'd' in the argument of a Validity_ Checks
58 -- pragma (or the initial default value is used, set True), then left side
59 -- subscripts and case statement arguments are checked for validity. This
60 -- switch is also set by default if no -gnatV switch is used and no
61 -- Validity_Checks pragma is processed.
62
63 Validity_Check_Floating_Point : Boolean := False;
64 -- Normally validity checking applies only to discrete values (integer
65 -- and enumeration types). If this switch is set to True using -gnatVf
66 -- or an 'f' in the argument of a Validity_Checks pragma, then floating-
67 -- point values are also checked. The context in which such checks
68 -- occur depends on other flags, e.g. if Validity_Check_Copies is also
69 -- set then floating-point values on the right side of an assignment
70 -- will be validity checked.
71
72 Validity_Check_In_Out_Params : Boolean := False;
73 -- Controls the validity checking of IN OUT parameters. If this switch
74 -- is set to True using -gnatVm or a 'm' in the argument of a pragma
75 -- Validity_Checks, then the initial value of all IN OUT parameters
76 -- will be checked at the point of call of a procedure. Note that the
77 -- character 'm' here stands for modified (parameters).
78
79 Validity_Check_In_Params : Boolean := False;
80 -- Controls the validity checking of IN parameters. If this switch is
81 -- set to True using -gnatVi or an 'i' in the argument of a pragma
82 -- Validity_Checks, then the initial value of all IN parameters
83 -- will be checked at the point of call of a procedure or function.
84
85 Validity_Check_Operands : Boolean := False;
86 -- Controls validity checking of operands. If this switch is set to
87 -- True using -gnatVo or an 'o' in the argument of a Validity_Checks
88 -- pragma, then operands of all predefined operators and attributes
89 -- will be validity checked.
90
91 Validity_Check_Parameters : Boolean := False;
92 -- This controls validity treatment for parameters within a subprogram.
93 -- Normally if validity checking is enabled for parameters on a call
94 -- (Validity_Check_In[_Out]_Params) then an assumption is made that the
95 -- parameter values are valid on entry and not checked again within a
96 -- procedure. Setting Validity_Check_Parameters removes this assumption
97 -- and ensures that no assumptions are made about parameters, so that
98 -- they will always be checked.
99
100 Validity_Check_Returns : Boolean := False;
101 -- Controls validity checking of returned values. If this switch is set
102 -- to True using -gnatVr, or an 'r' in the argument of a Validity_Checks
103 -- pragma, then the expression in a RETURN statement is validity checked.
104
105 Validity_Check_Subscripts : Boolean := False;
106 -- Controls validity checking of subscripts. If this switch is set to
107 -- True using -gnatVs, or an 's' in the argument of a Validity_Checks
108 -- pragma, then all subscripts are checked for validity. Note that left
109 -- side subscript checking is controlled also by Validity_Check_Default.
110 -- If Validity_Check_Subscripts is True, then all subscripts are checked,
111 -- otherwise if Validity_Check_Default is True, then left side subscripts
112 -- are checked, otherwise no subscripts are checked.
113
114 Validity_Check_Tests : Boolean := False;
115 -- Controls validity checking of tests that occur in conditions (i.e. the
116 -- tests in IF, WHILE, and EXIT statements, and in entry guards). If this
117 -- switch is set to True using -gnatVt, or a 't' in the argument of a
118 -- Validity_Checks pragma, then all such conditions are validity checked.
119
120 Force_Validity_Checks : Boolean := False;
121 -- Normally, operands that do not come from source (i.e. cases of expander
122 -- generated code) are not checked, if this flag is set True, then checking
123 -- of such operands is forced (if Validity_Check_Operands is set).
124
125 -----------------
126 -- Subprograms --
127 -----------------
128
129 procedure Set_Default_Validity_Check_Options;
130 -- This procedure is called to set the default validity checking options
131 -- that apply if no Validity_Check switches or pragma is given.
132
133 procedure Set_Validity_Check_Options
134 (Options : String;
135 OK : out Boolean;
136 Err_Col : out Natural);
137 -- This procedure is called to set the validity check options that
138 -- correspond to the characters in the given Options string. If
139 -- all options are valid, then Set_Default_Validity_Check_Options
140 -- is first called to set the defaults, and then the options in the
141 -- given string are set in an additive manner. If any invalid character
142 -- is found, then OK is False on exit, and Err_Col is the index in
143 -- in options of the bad character. If all options are valid, then
144 -- OK is True on return, and Err_Col is set to options'Last + 1.
145
146 procedure Set_Validity_Check_Options (Options : String);
147 -- Like the above procedure, except that the call is simply ignored if
148 -- there are any error conditions, this is for example appropriate for
149 -- calls where the string is known to be valid, e.g. because it was
150 -- obtained by Save_Validity_Check_Options.
151
152 procedure Reset_Validity_Check_Options;
153 -- Sets all validity check options to off
154
155 subtype Validity_Check_Options is String (1 .. 16);
156 -- Long enough string to hold all options from Save call below
157
158 procedure Save_Validity_Check_Options
159 (Options : out Validity_Check_Options);
160 -- Sets Options to represent current selection of options. This
161 -- set can be restored by first calling Reset_Validity_Check_Options,
162 -- and then calling Set_Validity_Check_Options with the Options string.
163
164 end Validsw;