Better error messages with demangled names + location

[sloede]

Sometimes I start batch-wrapping a bunch of library functions to get a C++ wrapper more feature complete, but I overlook that some types have been used that have not been wrapped themselves yet. At the moment, one only gets a (to me) rather cryptic error message such as

C++ exception while wrapping module OpenFHE: No appropriate factory for type St3mapIjSt10shared_ptrIN8lbcrypto11EvalKeyImplINS1_12DCRTPolyImplIN9bigintdyn9mubintvecINS4_5ubintImEEEEEEEEESt4lessIjESaISt4pairIKjSB_EEE
ERROR: LoadError: No appropriate factory for type St3mapIjSt10shared_ptrIN8lbcrypto11EvalKeyImplINS1_12DCRTPolyImplIN9bigintdyn9mubintvecINS4_5ubintImEEEEEEEEESt4lessIjESaISt4pairIKjSB_EEE
Stacktrace:
 [1] register_julia_module
   @ CxxWrap.CxxWrapCore ~/.julia/packages/CxxWrap/5IZvn/src/CxxWrap.jl:393 [inlined]
 [2] readmodule(so_path_cb::OpenFHE.var"#1#2", funcname::Symbol, m::Module, flags::Nothing)
   @ CxxWrap.CxxWrapCore ~/.julia/packages/CxxWrap/5IZvn/src/CxxWrap.jl:751
 [3] wrapmodule(so_path_cb::Function, funcname::Symbol, m::Module, flags::Nothing)
   @ CxxWrap.CxxWrapCore ~/.julia/packages/CxxWrap/5IZvn/src/CxxWrap.jl:761
 [4] top-level scope
   @ /mnt/ssd/home/mschlott/hackathon/fhe/OpenFHE.jl/src/OpenFHE.jl:11
 [5] include
   @ Base ./Base.jl:495 [inlined]
 [6] include_package_for_output(pkg::Base.PkgId, input::String, depot_path::Vector{String}, dl_load_path::Vector{String}, load_path::Vector{String}, concrete_deps::Vector{Pair{Base.PkgId, UInt128}}, source::Nothing)
   @ Base ./loading.jl:2216
 [7] top-level scope
   @ stdin:3

While I am usually able to decipher which type is the offending one (in this case, St3mapIjSt10shared_ptrIN8lbcrypto11EvalKeyImplINS1_12DCRTPolyImplIN9bigintdyn9mubintvecINS4_5ubintImEEEEEEEEESt4lessIjESaISt4pairIKjSB_EEE probably refers to something starting with std::map<std::shared_ptr<lbcrypto..., it's usually rather cumbersume.

Thus, it would be great if there were a demangle function (or if such names were demangled automatically). Furthermore, it would be great - if possible - if the offending location in the wrapper library could be shown as well.

The latter probably requires passing the source location in C++ as something like <filename>:<lineno> with each call to add_type, method etc. Since this is C++, it would probably require an explicit argument (maybe using an appropriate LOC__ preproc macro) that would have to be explicitly given as an argument, but it would certainly make debugging much easier.

[giordano]

For what is worth, you can use c++filt:

% c++filt --no-strip-underscore _ZSt3mapIjSt10shared_ptrIN8lbcrypto11EvalKeyImplINS1_12DCRTPolyImplIN9bigintdyn9mubintvecINS4_5ubintImEEEEEEEEESt4lessIjESaISt4pairIKjSB_EEE
std::map<unsigned int, std::shared_ptr<lbcrypto::EvalKeyImpl<lbcrypto::DCRTPolyImpl<bigintdyn::mubintvec<bigintdyn::ubint<unsigned long>>>>>, std::less<unsigned int>, std::allocator<std::pair<unsigned int const, std::shared_ptr<lbcrypto::EvalKeyImpl<lbcrypto::DCRTPolyImpl<bigintdyn::mubintvec<bigintdyn::ubint<unsigned long>>>>>>>>

But I don't quite understand why the symbol you mentioned started with St instead of _Z...