Re: c++/10207: Empty structure initialization fails under C++ (but works under C)

Re: c++/10207: Empty structure initialization fails under C++ (but works under C)

[David R. Whipple]

The following reply was made to PR c++/10207; it has been noted by GNATS.

From: "David R. Whipple" <vencain@swbell.net>
To: gcc-gnats@gcc.gnu.org, gcc-bugs@gcc.gnu.org, nobody@gcc.gnu.org,
   gcc-prs@gcc.gnu.org
Cc:  
Subject: Re: c++/10207: Empty structure initialization fails under C++ (but
 works under C)
Date: Tue, 25 Mar 2003 17:50:02 -0600

 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10207
 
 I've subsequently noticed that the sizeof() returns zero for an empty C 
 structure while returning one under C++, presumably playing a role in 
 this problem.  Is there a mechanism to encourage C++ to collapse an 
 empty structure to zero bytes?  If so then perhaps that would circumvent 
 the reported problem.
 

Re: c++/10207: Empty structure initialization fails under C++ (but works under C)

[bangerth]

Synopsis: Empty structure initialization fails under C++ (but works under C)

State-Changed-From-To: open->analyzed
State-Changed-By: bangerth
State-Changed-When: Tue Mar 25 15:53:44 2003
State-Changed-Why:
    I can confirm this, with 3.3 and 3.4 as well. I think the
    syntax you use is actually C99, so somebody in the know
    should decide whether we also want to support it in C++.
    
    W.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10207

c++/10207: Empty structure initialization fails under C++ (but works under C)

[vencain]

>Number:         10207
>Category:       c++
>Synopsis:       Empty structure initialization fails under C++ (but works under C)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Mar 25 08:26:01 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     Marcus VenCain
>Release:        gcc version 3.2 20020903
>Organization:
>Environment:
(Red Hat Linux 8.0 3.2-7)
>Description:
Compiling the provided code works under C while producing the following using either gcc or g++:

parse error before `}' token
excess elements in aggregate initializer

The provided code is derived from headers designed for C programs that I must include but am not responsible for maintaining.
>How-To-Repeat:
typedef struct { } EmptyStruct;
typedef struct {EmptyStruct Empty;} DemoStruct;
void Func(void)
{
  DemoStruct Demo;
  Demo.Empty = (EmptyStruct) {};
}
>Fix:

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