10.1.6 Environment-Level Visibility Rules

   The normal visibility rules do not apply within a parent_unit_name or a context_clause, nor within a pragma that appears at the place of a compilation unit. The special visibility rules for those contexts are given here.

   Within the parent_unit_name at the beginning of a library_item, and within a with_clause, the only declarations that are visible are those that are library_items of the environment, and the only declarations that are directly visible are those that are root library_items of the environment. Notwithstanding the rules of 4.1.3, an expanded name in a with_clause may consist of a prefix that denotes a generic package and a selector_name that denotes a child of that generic package. (The child is necessarily a generic unit; see 10.1.1.)

   Within a use_clause or pragma that is within a context_clause, each library_item mentioned in a previous with_clause of the same context_clause is visible, and each root library_item so mentioned is directly visible. In addition, within such a use_clause, if a given declaration is visible or directly visible, each declaration that occurs immediately within the given declaration's visible part is also visible. No other declarations are visible or directly visible.

   Within the parent_unit_name of a subunit, library_items are visible as they are in the parent_unit_name of a library_item; in addition, the declaration corresponding to each body_stub in the environment is also visible.

   Within a pragma that appears at the place of a compilation unit, the immediately preceding library_item and each of its ancestors is visible. The ancestor root library_item is directly visible.