Exceptions may be declared and raised as described in the Ada 95 standard. However exception handlers are prohibited. The run-time system includes a user-defined function that is called whenever an exception is raised.
The predefined exceptions Program_Error, Numeric_Error and Constraint_Error are raised under the conditions given in the Ada 95 Standard.
The predefined exception Storage_Error is raised by an explicit raise statement, or when allocating the stack space for a task declaration.