Version 1.2 of ais/ai-00032.txt

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!standard 08.02 (05) 99-05-27 AI95-00032/02
!class confirmation 95-06-25
!status WG9 approved 96-12-07
!status ARG Approved 10-0-0 96-10-07
!status work item 95-07-06
!status received 95-06-25
!priority Low
!difficulty Easy
!subject visible part of a renaming

!summary

A library_unit_renaming_declaration must mention the renamed library unit in a with_clause. The renamed unit must be a library unit.

!question

Is this legal? (No.) It would seem to allow exportation of private information.

package P is private procedure Q; end;

procedure P.R renames P.Q; -- Illegal!

!response

P.Q is not a library unit, so cannot be renamed as a library unit, according to 10.1.1(14). If we changed the private declaration of Q into a private child P.Q, the renaming would still be illegal, because it does not mention P.Q in a with_clause, so P.Q is not visible. And such a with_clause would be illegal by 10.1.2(8).

!ACATS test

ACATS tests BA11010, BA11011, and BA11012 test similar cases to that discussed by this AI. The case discussed by the AI isn't different enough to warrant adding to these tests.

!appendix

!section 8.2(5) !section 8.2(4) !subject visible part of a renaming !reference AARM-8.2(5-9) !reference AARM-8.2(4) !from Jesper Joergensen 95-02-15 !keywords visible part, child unit, private child unit !reference as: 95-5106.a Jesper Joergensen 95-3-6>> !discussion I sent the following comment to ada-comment@sw-eng.fa...... but got absolutely no reaction. Since it seems that this mailing list is still active, I try here. The rule 8.2(4) prevents entities declared in the private part of a library unit to be visible in the visible part of its public children. However, the rules defining visible parts [8.2(5-9)] do not mention renamings. Therefore, I think that the following is actually legal although it should not be, because a private declaration is made externally visible: package P is private procedure Q; end; procedure P.R renames P.Q; Please, tell me that I'm wrong! /Jesper Joergensen, DDC-I **************************************************************** !section 8.2(5) !section 8.2(4) !subject visible part of a renaming !reference AARM-8.2(5-9) !reference AARM-8.2(4) !reference 95-5106.a Jesper Joergensen 95-02-15 !keywords visible part, child unit, private child unit !from Tucker Taft 95-03-06 !reference as: 95-5107.a Tucker Taft 95-3-6>> !discussion > I sent the following comment to ada-comment@sw-eng.fa...... but got absolutely > no reaction. Since it seems that this mailing list is still active, I try > here. We have not yet started using that mailing list. We will try to get it at least so that it forwards mail to "ada9x-mrt@inmet.com" in the near future. > The rule 8.2(4) prevents entities declared in the private part of a library > unit to be visible in the visible part of its public children. However, the > rules defining visible parts [8.2(5-9)] do not mention renamings. Therefore, > I think that the following is actually legal although it should not be, > because a private declaration is made externally visible: > > > package P is > private > procedure Q; > end; > > > procedure P.R renames P.Q; This is not legal, because "P.Q" is not visible. You need to add a "with" clause that mentions "P.Q". Having done that, you will necessarily have to make this library unit renaming into a private child. > Please, tell me that I'm wrong! Happily, you are wrong. See above. > /Jesper Joergensen, DDC-I -Tuck **************************************************************** !section 8.2(5) !section 8.2(4) !subject visible part of a renaming !reference AARM-8.2(5-9) !reference AARM-8.2(4) !reference 95-5106.a Jesper Joergensen 95-02-15 !keywords visible part, child unit, private child unit !reference 95-5107.a !from Bob Duff !reference as: 95-5186.a Robert A Duff 95-6-27>> !discussion > > The rule 8.2(4) prevents entities declared in the private part of a library > > unit to be visible in the visible part of its public children. However, the > > rules defining visible parts [8.2(5-9)] do not mention renamings. Therefore, > > I think that the following is actually legal although it should not be, > > because a private declaration is made externally visible: > > > > > > package P is > > private > > procedure Q; > > end; > > > > > > procedure P.R renames P.Q; > > This is not legal, because "P.Q" is not visible. You need to add > a "with" clause that mentions "P.Q". Having done that, you will > necessarily have to make this library unit renaming into a private > child. Actually, P.Q is not a library unit, so you can't "with" it. By 10.1.1(14), you can't rename it using a library_unit_renaming_declaration. > > Please, tell me that I'm wrong! > > Happily, you are wrong. See above. For a different reason. - Bob ****************************************************************