Next: , Previous: Pragma Check_Name, Up: Implementation Defined Pragmas

Pragma Check_Policy


     pragma Check_Policy
      ([Name   =>] Identifier,
       [Policy =>] POLICY_IDENTIFIER);
     POLICY_IDENTIFIER ::= On | Off | Check | Ignore

This pragma is similar to the predefined pragma Assertion_Policy, except that it controls sets of named assertions introduced using the Check pragmas. It can be used as a configuration pragma or (unlike Assertion_Policy) can be used within a declarative part, in which case it controls the status to the end of the corresponding construct (in a manner identical to pragma Suppress).

The identifier given as the first argument corresponds to a name used in associated Check pragmas. For example, if the pragma:

     pragma Check_Policy (Critical_Error, Off);

is given, then subsequent Check pragmas whose first argument is also Critical_Error will be disabled. The special identifier Assertion controls the behavior of normal Assert pragmas (thus a pragma Check_Policy with this identifier is similar to the normal Assertion_Policy pragma except that it can appear within a declarative part).

The special identifiers Precondition and Postcondition control the status of preconditions and postconditions. If a Precondition pragma is encountered, it is ignored if turned off by a Check_Policy specifying that Precondition checks are Off or Ignored. Similarly use of the name Postcondition controls whether Postcondition pragmas are recognized.

The check policy is Off to turn off corresponding checks, and On to turn on corresponding checks. The default for a set of checks for which no Check_Policy is given is Off unless the compiler switch -gnata is given, which turns on all checks by default.

The check policy settings Check and Ignore are also recognized as synonyms for On and Off. These synonyms are provided for compatibility with the standard Assertion_Policy pragma.