Re: c++filt and addr2line [was Re: c++filt causing flashing consolewindows]

[Ranjit Mathew <rmathew at hotmail dot com>]

Andrew Haley wrote:
> Ranjit Mathew writes:
>  > Øyvind Harboe wrote:
>  > > Is there a way I can turn off the invocation of "c++filt"
>  > > from my compiled app?
>  > 
>  > See:
>  > 
>  > http://gcc.gnu.org/onlinedocs/gcj/libgcj-Runtime-Properties.html
>  > 
>  > and the *.NameFinder.* properties. In particular,
>  > "gnu.gcj.runtime.NameFinder.demangle" and
>  > "gnu.gcj.runtime.NameFinder.use_addr2line".
>  > 
>  > I seem to remember that libiberty has the demangler
>  > functions and perhaps we can directly use that instead
>  > of invoking c++filt. 
> 
> addr2line can now do its own demangling, so we could dispense with
> c++filt in some cases.  However, symbols in shared objects are
> retrieved by dlsym(), so we still need to demangle that.

I was thinking of cp_demangle( ) in libiberty/cp-demangle.c.
It would ensure that we are always up to date with
the state of the art in demangling and not be affected by
older c++filt executables on the user machine which do
not understand "style=java".


>  > Ditto for using libbfd v/s invoking addr2line,
> 
> This idea seems to come up once or twice a year.
> 
> The problem is not technical: it is legal.  We cannot do this unless
> the licences of libbfd and libiberty are changed.  libiberty is LGPL,
> which might be OK in some cases, but it is not the same as
> GPL+exception.  We can't license libgcj under two licences.

But we (GCJ/libgcj and the rest of GCC) already use lots
of functions from libiberty! For example, I was the one
who submitted a patch to use the "xregex" functions
from libiberty for systems that do not have their
own regex functions in libc.


> line number information.  Many people want to keep this.
> Line numbers are the only remaining reason for all this
> machinery.

Hmmm...only for generating line numbers then, do we
need addr2line. That should be OK, I guess.

Ranjit.

-- 
Ranjit Mathew          Email: rmathew AT hotmail DOT com

Bangalore, INDIA.      Web: http://ranjitmathew.tripod.com/