From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cagney To: Alexandre Oliva Cc: Jim Wilson , gcc@gcc.gnu.org, gcc-patches@gcc.gnu.org, gdb@sources.redhat.com Subject: Re: C++ ptrmemfun break if FUNCTION_BOUNDARY < 2 * BITS_PER_UNIT Date: Tue, 17 Apr 2001 10:38:00 -0000 Message-id: <3ADC6574.FA61742A@cygnus.com> References: <200104062005.NAA13684@wilson.cygnus.com> X-SW-Source: 2001-04/msg00117.html Alexandre Oliva wrote: > > On Apr 6, 2001, Jim Wilson wrote: > > >In article you write: > > >> The C++ ABI v3 uses the least significant bit of the pfn to tell > >> non-virtual from virtual functions. > > There are also targets that use the low-order bit of the PC to determine > > processor mode. > > Good point. I think this is enough of a reason for us to have a > target configuration flag to switch between two different > representations of pointers to member functions. I wonder how GDB is > going to be able to tell one representation from the other... Perhaps > it's going to have to be hard-coded in GDB? Remember, nothing in GDB is hard coded (only half :-^). Either the v3 ABI would need to specify the exact mechanism that is valid for ISA foo (i.e. GDB would would be wired to assume that all MIPS use mechanism XYZ) or the debug/object info would need to describe the mechanism being used so that GDB could adjust its self accordingly. Andrew