1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 use rustc::hir::def_id::DefId;
12 use rustc::middle::lang_items::DropInPlaceFnLangItem;
14 use rustc::ty::adjustment::CustomCoerceUnsized;
15 use rustc::ty::subst::Kind;
16 use rustc::ty::{self, Ty, TyCtxt};
18 pub use rustc::ty::Instance;
19 pub use self::item::{MonoItem, MonoItemExt};
25 #[inline(never)] // give this a place in the profiler
26 pub fn assert_symbols_are_distinct<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>, trans_items: I)
27 where I: Iterator<Item=&'a MonoItem<'tcx>>
29 let mut symbols: Vec<_> = trans_items.map(|trans_item| {
30 (trans_item, trans_item.symbol_name(tcx))
33 (&mut symbols[..]).sort_by(|&(_, ref sym1), &(_, ref sym2)|{
37 for pair in (&symbols[..]).windows(2) {
38 let sym1 = &pair[0].1;
39 let sym2 = &pair[1].1;
42 let trans_item1 = pair[0].0;
43 let trans_item2 = pair[1].0;
45 let span1 = trans_item1.local_span(tcx);
46 let span2 = trans_item2.local_span(tcx);
48 // Deterministically select one of the spans for error reporting
49 let span = match (span1, span2) {
50 (Some(span1), Some(span2)) => {
51 Some(if span1.lo().0 > span2.lo().0 {
58 (None, Some(span)) => Some(span),
62 let error_message = format!("symbol `{}` is already defined", sym1);
64 if let Some(span) = span {
65 tcx.sess.span_fatal(span, &error_message)
67 tcx.sess.fatal(&error_message)
73 fn fn_once_adapter_instance<'a, 'tcx>(
74 tcx: TyCtxt<'a, 'tcx, 'tcx>,
76 substs: ty::ClosureSubsts<'tcx>,
78 debug!("fn_once_adapter_shim({:?}, {:?})",
81 let fn_once = tcx.lang_items().fn_once_trait().unwrap();
82 let call_once = tcx.associated_items(fn_once)
83 .find(|it| it.kind == ty::AssociatedKind::Method)
85 let def = ty::InstanceDef::ClosureOnceShim { call_once };
87 let self_ty = tcx.mk_closure_from_closure_substs(
90 let sig = substs.closure_sig(closure_did, tcx);
91 let sig = tcx.erase_late_bound_regions_and_normalize(&sig);
92 assert_eq!(sig.inputs().len(), 1);
93 let substs = tcx.mk_substs([
95 sig.inputs()[0].into(),
98 debug!("fn_once_adapter_shim: self_ty={:?} sig={:?}", self_ty, sig);
99 Instance { def, substs }
102 fn needs_fn_once_adapter_shim(actual_closure_kind: ty::ClosureKind,
103 trait_closure_kind: ty::ClosureKind)
106 match (actual_closure_kind, trait_closure_kind) {
107 (ty::ClosureKind::Fn, ty::ClosureKind::Fn) |
108 (ty::ClosureKind::FnMut, ty::ClosureKind::FnMut) |
109 (ty::ClosureKind::FnOnce, ty::ClosureKind::FnOnce) => {
110 // No adapter needed.
113 (ty::ClosureKind::Fn, ty::ClosureKind::FnMut) => {
114 // The closure fn `llfn` is a `fn(&self, ...)`. We want a
115 // `fn(&mut self, ...)`. In fact, at trans time, these are
116 // basically the same thing, so we can just return llfn.
119 (ty::ClosureKind::Fn, ty::ClosureKind::FnOnce) |
120 (ty::ClosureKind::FnMut, ty::ClosureKind::FnOnce) => {
121 // The closure fn `llfn` is a `fn(&self, ...)` or `fn(&mut
122 // self, ...)`. We want a `fn(self, ...)`. We can produce
123 // this by doing something like:
125 // fn call_once(self, ...) { call_mut(&self, ...) }
126 // fn call_once(mut self, ...) { call_mut(&mut self, ...) }
128 // These are both the same at trans time.
135 pub fn resolve_closure<'a, 'tcx> (
136 tcx: TyCtxt<'a, 'tcx, 'tcx>,
138 substs: ty::ClosureSubsts<'tcx>,
139 requested_kind: ty::ClosureKind)
142 let actual_kind = substs.closure_kind(def_id, tcx);
144 match needs_fn_once_adapter_shim(actual_kind, requested_kind) {
145 Ok(true) => fn_once_adapter_instance(tcx, def_id, substs),
146 _ => Instance::new(def_id, substs.substs)
150 pub fn resolve_drop_in_place<'a, 'tcx>(
151 tcx: TyCtxt<'a, 'tcx, 'tcx>,
153 -> ty::Instance<'tcx>
155 let def_id = tcx.require_lang_item(DropInPlaceFnLangItem);
156 let substs = tcx.intern_substs(&[ty.into()]);
157 Instance::resolve(tcx, ty::ParamEnv::reveal_all(), def_id, substs).unwrap()
160 pub fn custom_coerce_unsize_info<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
163 -> CustomCoerceUnsized {
164 let def_id = tcx.lang_items().coerce_unsized_trait().unwrap();
166 let trait_ref = ty::Binder(ty::TraitRef {
168 substs: tcx.mk_substs_trait(source_ty, &[target_ty])
171 match tcx.trans_fulfill_obligation( (ty::ParamEnv::reveal_all(), trait_ref)) {
172 traits::VtableImpl(traits::VtableImplData { impl_def_id, .. }) => {
173 tcx.coerce_unsized_info(impl_def_id).custom_kind.unwrap()
176 bug!("invalid CoerceUnsized vtable: {:?}", vtable);