Annotated Ada Reference Manual — Legal Information

J.15.11 Pragmas Priority and Interrupt_Priority

Syntax

1/3

{AI05-0229-1} The form of a pragma Priority is as follows:

2/3

pragma Priority (expression);

3/3

{AI05-0229-1} The form of a pragma Interrupt_Priority is as follows:

4/3

pragma Interrupt_Priority [(expression);]

Name Resolution Rules

5/3

{AI05-0229-1} The expected type for the expression in a Priority or Interrupt_Priority pragma is Integer.

Legality Rules

6/3

{AI05-0229-1} A Priority pragma is allowed only immediately within a task_definition, a protected_definition, or the declarative_part of a subprogram_body. An Interrupt_Priority pragma is allowed only immediately within a task_definition or a protected_definition.

7/3

{AI05-0229-1} For a Priority pragma that appears in the declarative_part of a subprogram_body, the expression shall be static, and its value shall be in the range of System.Priority.

Static Semantics

8/3

{AI05-0229-1} For an implementation that supports Annex D, a pragma Priority specifies the value of the Priority aspect (see D.1) and a pragma Interrupt_Priority specifies the value of the Interrupt_Priority aspect as follows:

9/3

If the pragma appears in a task_definition, the expression is associated with the aspect for the task type or single_task_declaration that contains the pragma;

10/3

If the pragma appears in a protected_definition, the expression is associated with the aspect for the protected type or single_protected_declaration that contains the pragma;

11/3

If the pragma appears in the declarative_part of a subprogram_body, the expression is associated with the aspect for the subprogram that contains the pragma.

12/3

{AI05-0229-1} If there is no expression in an Interrupt_Priority pragma, the Interrupt_Priority aspect has the value Interrupt_Priority'Last.

Wording Changes from Ada 2005

12.a/3

{AI05-0229-1} This clause is new. Pragmas Interrupt_Priority and Priority were moved here from D.1; aspects Interrupt_Priority and Priority live there now.

Ada 2005 and 2012 Editions sponsored in part by Ada-Europe