pragma Obsolescent; pragma Obsolescent ( [Message =>] static_string_EXPRESSION [,[Version =>] Ada_05]]); pragma Obsolescent ( [Entity =>] NAME [,[Message =>] static_string_EXPRESSION [,[Version =>] Ada_05]] );
This pragma can occur immediately following a declaration of an entity, including the case of a record component. If no Entity argument is present, then this declaration is the one to which the pragma applies. If an Entity parameter is present, it must either match the name of the entity in this declaration, or alternatively, the pragma can immediately follow an enumeration type declaration, where the Entity argument names one of the enumeration literals.
This pragma is used to indicate that the named entity is considered obsolescent and should not be used. Typically this is used when an API must be modified by eventually removing or modifying existing subprograms or other entities. The pragma can be used at an intermediate stage when the entity is still present, but will be removed later.
The effect of this pragma is to output a warning message on a reference to
an entity thus marked that the subprogram is obsolescent if the appropriate
warning option in the compiler is activated. If the
Message parameter is
present, then a second warning message is given containing this text. In
addition, a reference to the entity is considered to be a violation of pragma
This pragma can also be used as a program unit pragma for a package,
in which case the entity name is the name of the package, and the
pragma indicates that the entire package is considered
obsolescent. In this case a client
withing such a package
violates the restriction, and the
with clause is
flagged with warnings if the warning option is set.
Version parameter is present (which must be exactly
Ada_05, no other argument is allowed), then the
indication of obsolescence applies only when compiling in Ada 2005
mode. This is primarily intended for dealing with the situations
in the predefined library where subprograms or packages
have become defined as obsolescent in Ada 2005
Ada.Characters.Handling), but may be used anywhere.
The following examples show typical uses of this pragma:
package p is pragma Obsolescent (p, Message => "use pp instead of p"); end p; package q is procedure q2; pragma Obsolescent ("use q2new instead"); type R is new integer; pragma Obsolescent (Entity => R, Message => "use RR in Ada 2005", Version => Ada_05); type M is record F1 : Integer; F2 : Integer; pragma Obsolescent; F3 : Integer; end record; type E is (a, bc, 'd', quack); pragma Obsolescent (Entity => bc) pragma Obsolescent (Entity => 'd') function "+" (a, b : character) return character; pragma Obsolescent (Entity => "+"); end;
Note that, as for all pragmas, if you use a pragma argument identifier,
then all subsequent parameters must also use a pragma argument identifier.
So if you specify
Entity => for the
Entity argument, and a
argument is present, it must be preceded by