+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use dep_graph::DepNode;
+use hir::def_id::DefId;
+use ty::{self, Ty, TypeFoldable, Substs};
+use util::ppaux;
+
+use std::borrow::Cow;
+use std::fmt;
+use syntax::ast;
+
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+pub struct Instance<'tcx> {
+ pub def: InstanceDef<'tcx>,
+ pub substs: &'tcx Substs<'tcx>,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+pub enum InstanceDef<'tcx> {
+ Item(DefId),
+ // <fn() as FnTrait>::call_*
+ FnPtrShim(DefId, Ty<'tcx>),
+}
+
+impl<'tcx> InstanceDef<'tcx> {
+ #[inline]
+ pub fn def_id(&self) -> DefId {
+ match *self {
+ InstanceDef::Item(def_id) |
+ InstanceDef::FnPtrShim(def_id, _)
+ => def_id
+ }
+ }
+
+ #[inline]
+ pub fn def_ty<'a>(&self, tcx: ty::TyCtxt<'a, 'tcx, 'tcx>) -> Ty<'tcx> {
+ tcx.item_type(self.def_id())
+ }
+
+ #[inline]
+ pub fn attrs<'a>(&self, tcx: ty::TyCtxt<'a, 'tcx, 'tcx>) -> Cow<'tcx, [ast::Attribute]> {
+ tcx.get_attrs(self.def_id())
+ }
+
+ pub(crate) fn dep_node(&self) -> DepNode<DefId> {
+ // HACK: def-id binning, project-style; someone replace this with
+ // real on-demand.
+ let ty = match self {
+ &InstanceDef::FnPtrShim(_, ty) => Some(ty),
+ _ => None
+ }.into_iter();
+
+ DepNode::MirShim(
+ Some(self.def_id()).into_iter().chain(
+ ty.flat_map(|t| t.walk()).flat_map(|t| match t.sty {
+ ty::TyAdt(adt_def, _) => Some(adt_def.did),
+ ty::TyProjection(ref proj) => Some(proj.trait_ref.def_id),
+ _ => None,
+ })
+ ).collect()
+ )
+ }
+}
+
+impl<'tcx> fmt::Display for Instance<'tcx> {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self.def {
+ InstanceDef::Item(def) => {
+ ppaux::parameterized(f, self.substs, def, &[])
+ }
+ InstanceDef::FnPtrShim(def, ty) => {
+ ppaux::parameterized(f, self.substs, def, &[])?;
+ write!(f, " - shim({:?})", ty)
+ }
+ }
+ }
+}
+
+impl<'a, 'b, 'tcx> Instance<'tcx> {
+ pub fn new(def_id: DefId, substs: &'tcx Substs<'tcx>)
+ -> Instance<'tcx> {
+ assert!(substs.is_normalized_for_trans() && !substs.has_escaping_regions(),
+ "substs of instance {:?} not normalized for trans: {:?}",
+ def_id, substs);
+ Instance { def: InstanceDef::Item(def_id), substs: substs }
+ }
+
+ pub fn mono(tcx: ty::TyCtxt<'a, 'tcx, 'b>, def_id: DefId) -> Instance<'tcx> {
+ Instance::new(def_id, tcx.global_tcx().empty_substs_for_def_id(def_id))
+ }
+
+ #[inline]
+ pub fn def_id(&self) -> DefId {
+ self.def.def_id()
+ }
+}