C++ demangling of 64-bit symbols on ppc64

[Maynard Johnson]

Ian Lance Taylor wrote:

>Maynard Johnson <maynardj@us.ibm.com> writes:
>
>  
>
>>As the de facto maintainer of the ppc64 bits of oprofile, I was
>>recently asked to look into an oprofile bug where it was incorrectly
>>demangling 64-bit symbols.  The oprofile code uses the libiberty
>>function, cplus_demangle(), but is not getting back the right answer
>>for ppc64 64-bit symbols.  This appears to be more fallout from the
>>change (made a couple years ago or so) to the opd for ppc64, where the
>>leading "." was removed from 64-bit symbols.
>>
>>I hacked around the problem in my private oprofile src tree, but I'm
>>thinking this issue should be solved at its source.  I'm seeing this
>>problem on a SLES 10 system with binutils version 2.16.91.  Has this
>>possibly been resolved in a more recent binutils version or in CVS?
>>    
>>
>
>Can you give an example of a symbol which the demangler is not
>handling correctly?
>  
>
Below is the testcase provided to me by the person who reported it:

==========

void doit(char *str)
{
        while (1)
                ;
}

char *blah;
int main()
{
        doit(blah);
}

When built as 32bit:

# g++ -O2 test.c -o test

opreport -l gives:

42345    89.6627  test                     doit(char*)

However when built as 64bit:

# g++ -m64 -O2 test.c -o test

opreport -l gives:

6513     93.7392  test                     ._Z4doitPc

=================

Regards,
-Maynard

>Ian
>  
>