Re: c++/8964: [3.3 regression] [ABI] different mangling of names

Re: c++/8964: [3.3 regression] [ABI] different mangling of names

[Janis Johnson]

The following reply was made to PR c++/8964; it has been noted by GNATS.

From: Janis Johnson <janis187@us.ibm.com>
To: gcc-gnats@gcc.gnu.org, gcc-prs@gcc.gnu.org, catherin@ca.ibm.com,
   gcc-bugs@gcc.gnu.org, nobody@gcc.gnu.org
Cc:  
Subject: Re: c++/8964: [3.3 regression] [ABI] different mangling of names
Date: Mon, 23 Dec 2002 09:42:19 -0800

 PR c++/8964 reports a change in name mangling that is not
 affected by the --abi-version switch.  It's caused by this
 patch, which adds a -Wabi warning that is issued for this
 test case, and information to the documentation about this
 kind of code.
 
 Should the name mangling here be affected by --abi-version?
 
 --- gcc/gcc/ChangeLog ---
 
 2002-10-03  Mark Mitchell  <mark@codesourcery.com>
 
         * doc/invoke.texi (-Wabi): Document mangling bug.
 
 --- gcc/gcc/cp/ChangeLog ---
 
 2002-10-03  Mark Mitchell  <mark@codesourcery.com>
 
         PR c++/8006
         * mangle.c (CLASSTYPE_TEMPLATE_ID_P): Handle
         instances of template template parameters.
 
 My testing used the submitter's test case.
 
 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8964
 
 
 

Re: c++/8964: [3.3 regression] [ABI] different mangling of names

[bangerth]

Old Synopsis: 2 different templates mangled with the same name
New Synopsis: [3.3 regression] [ABI] different mangling of names

State-Changed-From-To: closed->analyzed
State-Changed-By: bangerth
State-Changed-When: Mon Dec 16 13:10:07 2002
State-Changed-Why:
    This little code
    ---------------------------
    template < class T,int I > struct A {
      typedef int X;
    };
    
    template<class T> struct A<T,3> {
      typedef char X;
    };
    
    template <template <class B,int I> class XX>
    void foo(typename XX<int,3>::X a){}
    
    int main() {
      foo<A>('x');   
    }
    -------------------------------
    yields different mangled names with 3.2 and 3.3, which
    is an ABI change that should probably not be there unless
    guarded by -fabi-version:
    
    tmp/g> /home/bangerth/bin/gcc-3.2.2-pre/bin/c++ -c x.cc
    tmp/g> nm x.o | grep foo
    00000000 W _Z3fooI1AEvN2XX1XE
    tmp/g> nm x.o | /home/bangerth/bin/gcc-3.2/bin/c++filt | grep foo
    00000000 W void foo<A>(XX::X)
    
    
    
    tmp/g> /home/bangerth/bin/gcc-3.3-pre/bin/c++ -c x.cc
    tmp/g> nm x.o | grep foo
    00000000 W _Z3fooI1AEvN2XXIiLi3EE1XE
    tmp/g> nm x.o | /home/bangerth/bin/gcc-3.2/bin/c++filt | grep foo
    00000000 W void foo<A>(XX<int, (int)3>::X)

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8964