Re: c++/6894: lookup of anonymous structure members does not work as in C frontend

Re: c++/6894: lookup of anonymous structure members does not work as in C frontend

[rth]

Synopsis: lookup of anonymous structure members does not work as in C frontend

State-Changed-From-To: open->closed
State-Changed-By: rth
State-Changed-When: Sat Jun  1 23:57:48 2002
State-Changed-Why:
    This isn't legal.
      struct Bar { struct Foo; };
    This is a forward declaration of Bar::Foo, and so doesn't do
    what you think it does.  Note that this is a Microsoft VC++
    extension that we don't support in the C++ front end.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6894

c++/6894: lookup of anonymous structure members does not work as in C frontend

[bernie]

>Number:         6894
>Category:       c++
>Synopsis:       lookup of anonymous structure members does not work as in C frontend
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          rejects-legal
>Submitter-Id:   net
>Arrival-Date:   Sat Jun 01 06:36:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     bernie@codewiz.org
>Release:        gcc-3.1
>Organization:
>Environment:
Linux x86
>Description:
The C frontend has the unnamed fields extension to
allow class-like inheritance by putting an unnamed
structure (the base class) as the first field of
another structure (the derivate class).

The C++ frontend does not reject unnamed fields, but
fails to lookup fields contained within the unnamed structure, making this feature useless.
>How-To-Repeat:
Compile this test case with g++:

#include <stdio.h>
int main(void)
{
        struct Foo { int a; };
        struct Bar { struct Foo; };
        Bar bar;
        printf("bar.a = %d", bar.a);
        return 0;
}

The reported error is:
 foo.cpp:7: `struct main()::Bar' has no member named `a'
>Fix:

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