Target CPU as native or Mac produces symbol(s) not found for architecture arm64

[samfrench]

When setting the target-cpu flag it produces an error on a Mac. This seems similar to #459 in that when using "aarch64-apple-darwin" it compiles fine. This would support older or a range of devices. I was compiling only for my machine to test the performance of the application. Would a target of native or apple not be supported? Compiling other programs which don't use Rustler seem to be fine with those target-cpu options.

The error is below.

error: linking with `cc` failed: exit status: 1
...
note: Undefined symbols for architecture arm64:
            "_enif_alloc_binary", referenced from:
                rustler::wrapper::binary::alloc::hbd6b102d2af1d00a in librustler-13b296a3bac33c1c.rlib[8](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.5.rcgu.o)
            "_enif_alloc_env", referenced from:
                rustler::env::OwnedEnv::new::heda6392d60f345f5 in librustler-13b296a3bac33c1c.rlib[8](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.5.rcgu.o)
            "_enif_free_env", referenced from:
                _$LT$rustler..env..OwnedEnv$u20$as$u20$core..ops..drop..Drop$GT$::drop::hfb63487b04c46c9e in librustler-13b296a3bac33c1c.rlib[8](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.5.rcgu.o)
            "_enif_get_list_cell", referenced from:
                rustler::wrapper::list::get_list_cell::hf2b22ce406914215 in librustler-13b296a3bac33c1c.rlib[8](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.5.rcgu.o)
            "_enif_get_uint", referenced from:
                rustler::types::primitive::_$LT$impl$u20$rustler..types..Decoder$u20$for$u20$u8$GT$::decode::h682ced9fb91c3ba8 in librustler-13b296a3bac33c1c.rlib[6](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.3.rcgu.o)
            "_enif_is_empty_list", referenced from:
                rustler::wrapper::check::is_empty_list::hb894eba731606f25 in librustler-13b296a3bac33c1c.rlib[3](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.0.rcgu.o)
            "_enif_is_list", referenced from:
                rustler::wrapper::check::is_list::h73d057caa72d0089 in librustler-13b296a3bac33c1c.rlib[3](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.0.rcgu.o)
            "_enif_make_atom_len", referenced from:
                rustler::wrapper::atom::make_atom::he1a589f825ddf525 in librustler-13b296a3bac33c1c.rlib[8](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.5.rcgu.o)
            "_enif_make_badarg", referenced from:
                rustler::wrapper::exception::raise_badarg::hfa9738d4683120ad in librustler-13b296a3bac33c1c.rlib[10](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.7.rcgu.o)
            "_enif_make_binary", referenced from:
                rustler::types::binary::Binary::from_owned::h8b2ef5f5199e5ea4 in librustler-13b296a3bac33c1c.rlib[8](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.5.rcgu.o)
            "_enif_make_copy", referenced from:
                rustler::term::Term::in_env::h6079339999972d62 in librustler-13b296a3bac33c1c.rlib[9](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.6.rcgu.o)
            "_enif_make_tuple_from_array", referenced from:
                rustler::wrapper::tuple::make_tuple::h3cc1fef0bc262a8f in librustler-13b296a3bac33c1c.rlib[8](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.5.rcgu.o)
            "_enif_open_resource_type_x", referenced from:
                rustler::resource::registration::open_resource_type::h3391be35ecde116c in librustler-13b296a3bac33c1c.rlib[8](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.5.rcgu.o)
            "_enif_raise_exception", referenced from:
                rustler::wrapper::exception::raise_exception::ha3d52d8a4a74d538 in librustler-13b296a3bac33c1c.rlib[10](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.7.rcgu.o)
            "_enif_release_binary", referenced from:
                _$LT$rustler..types..binary..OwnedBinary$u20$as$u20$core..ops..drop..Drop$GT$::drop::ha298f40f2aada569 in librustler-13b296a3bac33c1c.rlib[8](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.5.rcgu.o)
            "_enif_schedule_nif", referenced from:
                rustler::codegen_runtime::NifReturned::apply::h38e8c99ea689cd12 in librustler-13b296a3bac33c1c.rlib[7](rustler-13b296a3bac33c1c.rustler.900e6cbbbd8a2adc-cgu.4.rcgu.o)
          ld: symbol(s) not found for architecture arm64
          clang: error: linker command failed with exit code 1 (use -v to see invocation)

error: could not compile (lib) due to 1 previous error

[filmor]

Are you sure that the flags referenced here #459 (comment) are used? The symbols can't be linked on any environment as they are provided by the erl executable and dynamically linked when the NIF library is loaded.

[samfrench]

I am not sure if those flags are used. I have the file in the codebase. I assume they are used when compiling as it works when not setting the target-cpu to native or apple. Maybe that is not matching "macos" and I need to set those properties for whatever gets determined as the os. I would assume it would be the same though.

[filmor]

To say anything more, I'd need to see a reproducible example. The error you are running into is very likely the missing linker args.

Aside, the default target cpu for this target triple is Apple M1, shouldn't that be enough to get all interesting extensions?

Note to self (and @rusterlium/core): We could sidestep these issues and the need for the linker flags by dynamically assigning the symbols in nif_init using dlopen(NULL) and dlsym. We do something like this for Windows anyway, as that's how the ABI works. I'll create a PoC.

[samfrench]

If it's m1 then that should be enough. I am learning about it so probably asking questions that are not important. I am using an m3 but not sure that would make a difference.