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::{self, Ty, TyCtxt};
17 pub use rustc::ty::Instance;
18 pub use self::item::{MonoItem, MonoItemExt};
24 #[inline(never)] // give this a place in the profiler
25 pub fn assert_symbols_are_distinct<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>, mono_items: I)
26 where I: Iterator<Item=&'a MonoItem<'tcx>>
28 let mut symbols: Vec<_> = mono_items.map(|mono_item| {
29 (mono_item, mono_item.symbol_name(tcx))
32 symbols.sort_by_key(|sym| sym.1);
34 for pair in symbols.windows(2) {
35 let sym1 = &pair[0].1;
36 let sym2 = &pair[1].1;
39 let mono_item1 = pair[0].0;
40 let mono_item2 = pair[1].0;
42 let span1 = mono_item1.local_span(tcx);
43 let span2 = mono_item2.local_span(tcx);
45 // Deterministically select one of the spans for error reporting
46 let span = match (span1, span2) {
47 (Some(span1), Some(span2)) => {
48 Some(if span1.lo().0 > span2.lo().0 {
54 (span1, span2) => span1.or(span2),
57 let error_message = format!("symbol `{}` is already defined", sym1);
59 if let Some(span) = span {
60 tcx.sess.span_fatal(span, &error_message)
62 tcx.sess.fatal(&error_message)
68 fn fn_once_adapter_instance<'a, 'tcx>(
69 tcx: TyCtxt<'a, 'tcx, 'tcx>,
71 substs: ty::ClosureSubsts<'tcx>,
73 debug!("fn_once_adapter_shim({:?}, {:?})",
76 let fn_once = tcx.lang_items().fn_once_trait().unwrap();
77 let call_once = tcx.associated_items(fn_once)
78 .find(|it| it.kind == ty::AssociatedKind::Method)
80 let def = ty::InstanceDef::ClosureOnceShim { call_once };
82 let self_ty = tcx.mk_closure(closure_did, substs);
84 let sig = substs.closure_sig(closure_did, tcx);
85 let sig = tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
86 assert_eq!(sig.inputs().len(), 1);
87 let substs = tcx.mk_substs_trait(self_ty, &[sig.inputs()[0].into()]);
89 debug!("fn_once_adapter_shim: self_ty={:?} sig={:?}", self_ty, sig);
90 Instance { def, substs }
93 fn needs_fn_once_adapter_shim(actual_closure_kind: ty::ClosureKind,
94 trait_closure_kind: ty::ClosureKind)
97 match (actual_closure_kind, trait_closure_kind) {
98 (ty::ClosureKind::Fn, ty::ClosureKind::Fn) |
99 (ty::ClosureKind::FnMut, ty::ClosureKind::FnMut) |
100 (ty::ClosureKind::FnOnce, ty::ClosureKind::FnOnce) => {
101 // No adapter needed.
104 (ty::ClosureKind::Fn, ty::ClosureKind::FnMut) => {
105 // The closure fn `llfn` is a `fn(&self, ...)`. We want a
106 // `fn(&mut self, ...)`. In fact, at codegen time, these are
107 // basically the same thing, so we can just return llfn.
110 (ty::ClosureKind::Fn, ty::ClosureKind::FnOnce) |
111 (ty::ClosureKind::FnMut, ty::ClosureKind::FnOnce) => {
112 // The closure fn `llfn` is a `fn(&self, ...)` or `fn(&mut
113 // self, ...)`. We want a `fn(self, ...)`. We can produce
114 // this by doing something like:
116 // fn call_once(self, ...) { call_mut(&self, ...) }
117 // fn call_once(mut self, ...) { call_mut(&mut self, ...) }
119 // These are both the same at codegen time.
126 pub fn resolve_closure<'a, 'tcx> (
127 tcx: TyCtxt<'a, 'tcx, 'tcx>,
129 substs: ty::ClosureSubsts<'tcx>,
130 requested_kind: ty::ClosureKind)
133 let actual_kind = substs.closure_kind(def_id, tcx);
135 match needs_fn_once_adapter_shim(actual_kind, requested_kind) {
136 Ok(true) => fn_once_adapter_instance(tcx, def_id, substs),
137 _ => Instance::new(def_id, substs.substs)
141 pub fn resolve_drop_in_place<'a, 'tcx>(
142 tcx: TyCtxt<'a, 'tcx, 'tcx>,
144 -> ty::Instance<'tcx>
146 let def_id = tcx.require_lang_item(DropInPlaceFnLangItem);
147 let substs = tcx.intern_substs(&[ty.into()]);
148 Instance::resolve(tcx, ty::ParamEnv::reveal_all(), def_id, substs).unwrap()
151 pub fn custom_coerce_unsize_info<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
154 -> CustomCoerceUnsized {
155 let def_id = tcx.lang_items().coerce_unsized_trait().unwrap();
157 let trait_ref = ty::Binder::bind(ty::TraitRef {
159 substs: tcx.mk_substs_trait(source_ty, &[target_ty.into()])
162 match tcx.codegen_fulfill_obligation( (ty::ParamEnv::reveal_all(), trait_ref)) {
163 traits::VtableImpl(traits::VtableImplData { impl_def_id, .. }) => {
164 tcx.coerce_unsized_info(impl_def_id).custom_kind.unwrap()
167 bug!("invalid CoerceUnsized vtable: {:?}", vtable);