ffi object file name and parameterized modules

[weaversa]

Here we have a foreign definition in a parameterized module. We create an instantiation of that module and try to load it in cryptol. Cryptol looks for the foreign declaration using the name of the instantiated module rather than the parameterized module.

The test is here: https://github.com/weaversa/cryptol-ffi-tests

$ make
$ cryptol shatest_8.cry
┏━╸┏━┓╻ ╻┏━┓╺┳╸┏━┓╻
┃  ┣┳┛┗┳┛┣━┛ ┃ ┃ ┃┃
┗━╸╹┗╸ ╹ ╹   ╹ ┗━┛┗━╸
version 2.13.0.99 (7e2613a, modified)
https://cryptol.net  :? for help

Loading module Cryptol
Loading module shatest
Loading module shatest_8
[error] Failed to load foreign implementations for module shatest_8:
    Could not load foreign source for module located at cryptol-ffi-tests/shatest_8.cry:
        user error (dlopen: dlopen(cryptol-ffi-tests/shatest_8.dylib, 0x0002): tried: 'cryptol-ffi-tests/shatest_8.dylib' (no such file))
        user error (dlopen: dlopen(cryptol-ffi-tests/shatest_8.so, 0x0002): tried: 'cryptol-ffi-tests/shatest_8.so' (no such file))

[yav]

FFI and parameterized do not work with the old module system. They do work with the new one, but we reject foreign declarations in functors, see comments on #1449