VHDL Issue Number:        2078

Language_Version          VHDL-2002
Classification            Language Modeling Enhancement or Deficiency
Summary                   Allow attribute declaration/specification in package body
Relevant_LRM_Sections     2.6 Package bodies
                          2.5 Package declarations
Related_Issues            
Key_Words_and_Phrases     Foreign subprograms
                          Attribute definition/specification in package body
Authors_Name              Ernst Christen
Authors_Phone_Number      503-547-6096
Authors_Fax_Number        
Authors_Email_Address     Ernst.Christen@synopsys.com
Authors_Affiliation       Synopsys, Inc.
Authors_Address1          2025 NW Cornelius Pass Rd.
Authors_Address2          Hillsboro, OR 97124
Authors_Address3          

Current Status:           VASG-Approved

Superseded By:

------------------------
Date Submitted:           21 November 2005
Date Analyzed:            02 December 2005
Author of Analysis:       Chuck Swart
Revision Number:          3
Date Last Revised:        04 May 2006

Description of Problem
----------------------

The definition of package_body_declarative_item does not include the
productions attribute_declaration and attribute_specification for no
apparent reason. This makes it impossible to declare a (public)
subprogram in a package whose definition depends on a private foreign
subprogram. The only way around this restriction is to make the
foreign subprogram public, i.e. to include its declaration and the
corresponding attribute specification in the package. This workaround
unnecessarily exposes a part of the implementation of the original
function, which is undesirable.

Proposed Resolution
-------------------

Allow attribute declarations and attribute specifications to occur as
package body declarative items.

VASG-ISAC Analysis & Rationale
------------------------------

The ISAC cannot think of any reason for not allowing attribute
declarations and attribute specifications in package bodies. This is
probably an oversight. Perhaps the early language authors thought that
attribute declarations and specifications weren't needed or useful in
package bodies.

The problem that the author states is legitimate. Also, as a general
principle, declarative parts should be as uniform as is reasonable.

VASG-ISAC Recommendation for IEEE Std 1076-2002
-----------------------------------------------

Under the assumption that this situation was an oversight, interpret
the LRM as if the proposed resolution were in effect.

VASG-ISAC Recommendation for Future Revisions
---------------------------------------------

Adopt the proposed resolution.

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