Re: c++/8021: undefined reference to virtual thunk

Re: c++/8021: undefined reference to virtual thunk

[bangerth]

Synopsis: undefined reference to virtual thunk

State-Changed-From-To: open->analyzed
State-Changed-By: bangerth
State-Changed-When: Mon Nov  4 15:12:46 2002
State-Changed-Why:
    Right, a regression w.r.t. 2.95. It works on the main trunk,
    though.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8021

Re: c++/8021: undefined reference to virtual thunk

[mmitchel]

Synopsis: undefined reference to virtual thunk

State-Changed-From-To: analyzed->closed
State-Changed-By: mmitchel
State-Changed-When: Wed Nov  6 18:07:47 2002
State-Changed-Why:
    Will not be fixed in GCC 3.2.x releases.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8021

c++/8021: undefined reference to virtual thunk

[grigory]

>Number:         8021
>Category:       c++
>Synopsis:       undefined reference to virtual thunk
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Sep 24 07:56:04 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Grigory Zagorodnev
>Release:        3.2
>Organization:
>Environment:
Red Hat Linux release 7.3.94 ((null))
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --host=i386-redhat-linux --with-system-zlib --enable-__cxa_atexit
Thread model: posix
gcc version 3.2 (Red Hat Linux Rawhide 3.2-1)
>Description:
The Issue
---------
G++ compiler gives "undefined reference to `virtual thunk..." error message while building the following test-case.

Testcase
--------
	struct C3 {
	    virtual int f8() { }
	};
	
	struct C4: virtual C3 { };
	
	struct C2: virtual C3,  C4 {
	    int i;
	    virtual int f8() {}
	};
	
	struct C1: virtual C2 {
	};
	
	C1 o1;
	
	int main() {
	    return 0;
	}

Command line is:
	$ g++ -c fail.cpp
	$ g++ fail.o

Error Message
-------------
fail.o(.gnu.linkonce.r._ZTC2C14_2C2+0x20): undefined reference to `virtual thunk [v:0,-12] to C2::f8()'
fail.o(.gnu.linkonce.r._ZTV2C1+0x14): undefined reference to `virtual thunk [v:0,-12] to C2::f8()'
collect2: ld returned 1 exit status
>How-To-Repeat:

>Fix:

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