c++/2384: Class that throws itself

c++/2384: Class that throws itself

[Peter Schmid]

>Number:         2384
>Category:       c++
>Synopsis:       Class that throws itself
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          rejects-legal
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 25 08:36:01 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     Peter Schmid
>Release:        3.1 20010324 (experimental)
>Organization:
TU Darmstadt
>Environment:
System: Linux kiste 2.4.2 #34 Sun Feb 25 20:03:34 CET 2001 i686 unknown
Architecture: i686
SuSE 7.1
glibc 2.2
GNU ld version 2.11.90.0.1 (with BFD 2.11.90.0.1)
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../gcc/configure --enable-shared --disable-nls --enable-threads=posix --enable-long-long --enable-languages=c,c++,f77,objc
>Description:
Recently I came across the following code te.C. G++ 2.95.2 accepts
the code but gcc 3 does not. Is this code legal?

>How-To-Repeat:
Source code te.C

class exception
{
public:
	bool flag; 
	void proc(void) throw(exception);	
};

Compiling te.C

g++ -v -c te.C -W -Wall
Reading specs from /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
Configured with: ../gcc/configure --enable-shared --disable-nls --enable-threads=posix --enable-long-long --enable-languages=c,c++,f77,objc
gcc version 3.1 20010324 (experimental)
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/cc1plus -v -D__GNUC__=3 -D__GNUC_MINOR__=1 -D__GNUC_PATCHLEVEL__=0 -D__ELF__ -Dunix -Dlinux -D__ELF__ -D__unix__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__STDC_HOSTED__=1 -W -Wall -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i686__ -D__tune_pentiumpro__ te.C -D__GNUG__=3 -D_GNU_SOURCE -D__EXCEPTIONS -D__GXX_ABI_VERSION=100 -quiet -dumpbase te.C -W -Wall -version -o /tmp/cc40hxwv.s
GNU CPP version 3.1 20010324 (experimental) (cpplib) (i386 Linux/ELF)
GNU C++ version 3.1 20010324 (experimental) (i686-pc-linux-gnu)
	compiled by GNU C version 3.1 20010324 (experimental).
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include/g++-v3
 /usr/local/include/g++-v3/i686-pc-linux-gnu
 /usr/local/include
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/include
 /usr/local/i686-pc-linux-gnu/include
 /usr/include
End of search list.
te.C:5: invalid use of undefined type `class exception'
te.C:2: forward declaration of `class exception'


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

Re: c++/2384: Class that throws itself

[Martin Sebor]

The following reply was made to PR c++/2384; it has been noted by GNATS.

From: Martin Sebor <sebor@roguewave.com>
To: Peter Schmid <schmid@snake.iap.physik.tu-darmstadt.de>
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: c++/2384: Class that throws itself
Date: Sun, 25 Mar 2001 12:21:42 -0700

 Peter Schmid wrote:
 > 
 > >Number:         2384
 > >Category:       c++
 > >Synopsis:       Class that throws itself
 ...
 > Recently I came across the following code te.C. G++ 2.95.2 accepts
 > the code but gcc 3 does not. Is this code legal?
 
 Not according to 9.2, p2:
 
 "A class is considered a completely-defined object type (basic.types) (or
 complete type) at the closing } of the class-specifier. Within the class
 member-specification, the class is regarded as complete within function bodies,
 default arguments and constructor ctor-initializers (including such things in
 nested classes). Otherwise it is regarded as incomplete within its own class
 member-specification."
 
 Regards
 Martin
 
 > 
 > >How-To-Repeat:
 > Source code te.C
 > 
 > class exception
 > {
 > public:
 >         bool flag;
 >         void proc(void) throw(exception);
 > };
 > 
 ...