Re: c++/8891: Unexplicit error message about naming conflict

Re: c++/8891: Unexplicit error message about naming conflict

[bangerth]

Synopsis: Unexplicit error message about naming conflict

State-Changed-From-To: open->feedback
State-Changed-By: bangerth
State-Changed-When: Tue Dec 10 06:55:08 2002
State-Changed-Why:
    I don't know what to do with this report, since the message
    is probably the best you can get. In any case, there is
    no _naming conflict_: declaring an enum member and a
    class with the same name is just fine, it's only when you
    access that you have to make clear what you want: by
    default, lookup happens _within_ the class, so you get 
    the enum name, which of course does not go well with the
    "operator new". If you want the class name, you have to
    specify that:
        Foo* fct() { return new ::BadName; }
    This compiles just fine.
    
    So what you request is that upon seeing the bogus
       new enum-value;
    line, the compiler looks up whether somewhere, outside of
    its usual search area, there is class name with the same
    name as that enum value. I think this is asking for too
    much. 
    
    Maybe someone of the C++ front end guys can comment on what
    we should do with this request.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8891

c++/8891: Unexplicit error message about naming conflict

[benoit.sibaud]

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>Number:         8891
>Category:       c++
>Synopsis:       Unexplicit error message about naming conflict
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Dec 10 06:36:04 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     Benoît Sibaud
>Release:        gcc-3.2.1
>Organization:
>Environment:
Debian Sarge i686-pc-linux-gnu
>Description:
class Foo
{
protected:
    enum {BadName, A, B, C};
};
class BadName : public Foo
{
};
class Toto : public Foo
{
 public:
    Foo* fct() { return new BadName; }
};

$ g++ -Wall foo.cpp
foo.cpp: In member function `Foo* Toto::fct()':
foo.cpp:18: parse error before `;' token
foo.cpp:18: warning: no return statement in function returning non-void

Conflict between ::BadName and BadName in Foo enum. The error message is not really helpful (the enum was deeply hidden in a class hierarchy in my case).
Tested with several 2.95.2, 3.0.x, 3.1.x and 3.2.x versions.
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: