Re: ada/5690: renaming subprograms and default_expression

[gnat-dev at buzco dot nyct dot net]

The following reply was made to PR ada/5690; it has been noted by GNATS.

From: gnat-dev@buzco.nyct.net
To: gcc-gnats@gcc.gnu.org
Cc: fw@deneb.enyo.de
Subject: Re: ada/5690: renaming subprograms and default_expression
Date: Wed, 24 Apr 2002 08:20:19 -0400

 On 02-02-14 16:01:49 fw@deneb.enyo.de wrote:
 
 | > Number:	   5690
 | > Category:	   ada
 | > Synopsis:	   renaming subprograms and default_expression
 | > Confidential:   no
 | > Severity:	   critical
 | > Priority:	   high
 | > Responsible:    unassigned
 | > State:	   open
 | > Class:	   rejects-legal
 | > Submitter-Id:   net
 | > Arrival-Date:   Thu Feb 14 08:06:00 PST 2002
 | > Closed-Date:
 | > Last-Modified:
 | > Originator:	   fw@deneb.enyo.de
 | > Release:	   GCC 3.1 2002-02-12
 | > Organization:
 | > Environment:
 | Debian GNU/Linux unstable, x86
 | > Description:
 | The attached program appears to be legal, but compilation results in the following error messages:
 
 | defaults.adb:6:14: not fully conformant with declaration at line 4
 | defaults.adb:6:14: default expression for "X" does not match
 | > How-To-Repeat:
 | Compile the attached program.
 | > Fix:
 
 === End quoted text ===
 
 This is "questionable, but should be legal" code !
 
 The relevant part of the RM (§ 8.5.4 Subprogram Renaming Declarations)
 defines in ¶ 1 :
    1.  A subprogram_renaming_declaration can serve as the completion of a
        subprogram_declaration; such a renaming_declaration is called a
        renaming-as-body. A subprogram_renaming_declaration that is not a
        completion is called a renaming-as-declaration, and is used to
        rename a subprogram ...
 
 (This can be read at
 http://buzco.nyct.net/Programming/lang/Ada/gnat/3.14/arm95/arm95_134.html
 most of the time (I have about 90 % availability), and is of course in
 the RM shipped w/ gnat-3.14 and I guess w/ the new gcc-ada docs.)
 
 Your sample tries to change the default argument w/ a renaming-as-body,
 which I can see could be useful at times. The RM does +not+ explicitly
 state that this is legal, and all the examples show a
 renaming-as-declaration.
 
 GNAT-3.14p exhibits similar behaviour.
 
 I will map out the scope of the problem (eg, what happens if this is a
 package w/ "original" defined in another pkg, etc) and see if I can
 track down the code.
 
 Meanwhile, if some Compiler Lawyer can identify if this is really a bug
 in the compiler or just the manual, that would help.
 
 --
 Buz Cory of BuzCo Systems -- New York NY USA http://BuzCo.nyct.net
 <gnat-dev@BuzCo.nyct.net> (Buz as GNAT Programmer)
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