compiler/rustc_monomorphize/src/lib.rs

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