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 #![feature(in_band_lifetimes)]
   7 #![recursion_limit = "256"]
   8 #![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
   9
  10 #[macro_use]
  11 extern crate tracing;
  12 #[macro_use]
  13 extern crate rustc_middle;
  14
  15 use rustc_hir::lang_items::LangItem;
  16 use rustc_middle::traits;
  17 use rustc_middle::ty::adjustment::CustomCoerceUnsized;
  18 use rustc_middle::ty::query::Providers;
  19 use rustc_middle::ty::{self, Ty, TyCtxt};
  20
  21 mod collector;
  22 mod partitioning;
  23 mod polymorphize;
  24 mod util;
  25
  26 fn custom_coerce_unsize_info<'tcx>(
  27     tcx: TyCtxt<'tcx>,
  28     source_ty: Ty<'tcx>,
  29     target_ty: Ty<'tcx>,
  30 ) -> CustomCoerceUnsized {
  31     let def_id = tcx.require_lang_item(LangItem::CoerceUnsized, None);
  32
  33     let trait_ref = ty::Binder::dummy(ty::TraitRef {
  34         def_id,
  35         substs: tcx.mk_substs_trait(source_ty, &[target_ty.into()]),
  36     });
  37
  38     match tcx.codegen_fulfill_obligation((ty::ParamEnv::reveal_all(), trait_ref)) {
  39         Ok(traits::ImplSource::UserDefined(traits::ImplSourceUserDefinedData {
  40             impl_def_id,
  41             ..
  42         })) => tcx.coerce_unsized_info(impl_def_id).custom_kind.unwrap(),
  43         impl_source => {
  44             bug!("invalid `CoerceUnsized` impl_source: {:?}", impl_source);
  45         }
  46     }
  47 }
  48
  49 pub fn provide(providers: &mut Providers) {
  50     partitioning::provide(providers);
  51     polymorphize::provide(providers);
  52 }