Cannot demangle a handful of symbols from a Linux build of Firefox

[gabrielesvelto]

I've used the current master branch of cpp_demangle on the symbols produced by a local Firefox build on my machine and found 78 that cannot be demangled. The list of affected symbols is available here. These were generated by clang 14.0.5. As always with this kind of issues it's unclear if it's cpp_demangle's fault or the symbols were mis-mangled by clang.

[gabrielesvelto]

I've fed the symbols into llvm-cxxfilt and the results are here. These symbols seem to share one of the two following conditions:

• They contain parameters that are function pointers qualified as noexcept
• They contain a at offset <number> component which I'm not familiar with.

Here's a couple of examples:

bool __gnu_cxx::__ops::_Iter_negate<int (*)(int) noexcept>::operator()<char const*>(char const*)
nsresult mozilla::extensions::AtomSet::Get<&(mozilla::extensions::WILDCARD_SCHEMES.<char const* at offset 0>)>(RefPtr<mozilla::extensions::AtomSet>&)

[khuey]

I did noexcept (the non-deprecated variants anyways).

at offset <number> hasn't actually made it into the spec yet: itanium-cxx-abi/cxx-abi#47