Adding gdb-patches, since demangling affects gdb. Ref: https://gcc.gnu.org/ml/gcc-patches/2018-12/msg00407.html
On 12/07/2018 10:40 AM, Jakub Jelinek wrote: > On Fri, Dec 07, 2018 at 10:27:17AM +0000, Nick Clifton wrote: >>>> Looks good to me. Independently, do you see a reason not to disable the >>>> old demangler entirely? >>> >>> Like so. Does anyone object to this? These mangling schemes haven't >>> been relevant in decades. >> >> I am not really familiar with this old scheme, so please excuse my ignorance >> in asking these questions: >> >> * How likely is it that there are old toolchain in use out there that >> still >> use the v2 mangling ? Ie I guess that I am asking "which generation(s) >> of gcc used v2 mangling ?" > > GCC 3.0 and up used the new (Itanium C++ ABI) mangling, 2.95 and older used > the old > mangling (2.96-RH used the new mangling I believe). > So you need compiler older than 17.5 years to have the old mangling. > Such a compiler didn't support most of the contemporarily used platforms > though at all (e.g. x86-64, powerpc64le, aarch64, I believe not even > powerpc64-linux). > Yeah. I guess the question would be whether it is reasonable to expect that people will still need to debug&inspect (with gdb, c++filt, etc.) any such old binary, and that they will need to do it with with modern tools, as opposed to sticking with older binutils&gdb, and how often would that be needed. I would say that it's very, very unlikely, and not worth it of the maintenance burden. Last I heard of 2.95-produced binaries I think was for some ancient gcc-2.95-based cross compiler that was still being minimally maintained, because it was needed to build&maintain some legacy stuff. That was maybe over 8 years ago, and it was off trunk. It's probably dead by now. And if isn't dead, whoever maintains the compiler off trunk certainly can also maintain old-ish binutils & gdb off trunk. Thanks, Pedro Alves
