compiler/rustc_monomorphize/src/lib.rs

   1 #![feature(array_windows)]
   2 #![feature(bool_to_option)]
   3 #![feature(crate_visibility_modifier)]
   4 #![feature(control_flow_enum)]
   5 #![feature(let_else)]
   6 #![recursion_limit = "256"]
   7
   8 #[macro_use]
   9 extern crate tracing;
  10 #[macro_use]
  11 extern crate rustc_middle;
  12
  13 use rustc_hir::lang_items::LangItem;
  14 use rustc_middle::traits;
  15 use rustc_middle::ty::adjustment::CustomCoerceUnsized;
  16 use rustc_middle::ty::query::Providers;
  17 use rustc_middle::ty::{self, Ty, TyCtxt};
  18
  19 mod collector;
  20 mod partitioning;
  21 mod polymorphize;
  22 mod util;
  23
  24 fn custom_coerce_unsize_info<'tcx>(
  25     tcx: TyCtxt<'tcx>,
  26     source_ty: Ty<'tcx>,
  27     target_ty: Ty<'tcx>,
  28 ) -> CustomCoerceUnsized {
  29     let def_id = tcx.require_lang_item(LangItem::CoerceUnsized, None);
  30
  31     let trait_ref = ty::Binder::dummy(ty::TraitRef {
  32         def_id,
  33         substs: tcx.mk_substs_trait(source_ty, &[target_ty.into()]),
  34     });
  35
  36     match tcx.codegen_fulfill_obligation((ty::ParamEnv::reveal_all(), trait_ref)) {
  37         Ok(traits::ImplSource::UserDefined(traits::ImplSourceUserDefinedData {
  38             impl_def_id,
  39             ..
  40         })) => tcx.coerce_unsized_info(impl_def_id).custom_kind.unwrap(),
  41         impl_source => {
  42             bug!("invalid `CoerceUnsized` impl_source: {:?}", impl_source);
  43         }
  44     }
  45 }
  46
  47 pub fn provide(providers: &mut Providers) {
  48     partitioning::provide(providers);
  49     polymorphize::provide(providers);
  50 }