# Function rustc_monomorphize::is_call_from_compiler_builtins_to_upstream_monomorphization

source ·

    pub fn is_call_from_compiler_builtins_to_upstream_monomorphization<'tcx>(
        tcx: TyCtxt<'tcx>,
        instance: Instance<'tcx>
    ) -> bool

Expand description

Returns whether a call from the current crate to the `Instance` would produce a call from `compiler_builtins` to a symbol the linker must resolve.

Such calls from `compiler_bultins` are effectively impossible for the linker to handle. Some linkers will optimize such that dead calls to unresolved symbols are not an error, but this is not guaranteed. So we used this function in codegen backends to ensure we do not generate any unlinkable calls.