1 // Copyright 2018 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.
13 use rustc::ty::ToPredicate;
14 use rustc::ty::subst::Subst;
15 use rustc::infer::InferOk;
16 use syntax_pos::DUMMY_SP;
18 use core::DocAccessLevels;
22 use self::def_ctor::{get_def_from_def_id, get_def_from_node_id};
24 pub struct BlanketImplFinder<'a, 'tcx: 'a, 'rcx: 'a, 'cstore: 'rcx> {
25 pub cx: &'a core::DocContext<'a, 'tcx, 'rcx, 'cstore>,
28 impl<'a, 'tcx, 'rcx, 'cstore> BlanketImplFinder <'a, 'tcx, 'rcx, 'cstore> {
29 pub fn new(cx: &'a core::DocContext<'a, 'tcx, 'rcx, 'cstore>) -> Self {
30 BlanketImplFinder { cx }
33 pub fn get_with_def_id(&self, def_id: DefId) -> Vec<Item> {
34 get_def_from_def_id(&self.cx, def_id, &|def_ctor| {
35 self.get_blanket_impls(def_id, &def_ctor, None)
39 pub fn get_with_node_id(&self, id: ast::NodeId, name: String) -> Vec<Item> {
40 get_def_from_node_id(&self.cx, id, name, &|def_ctor, name| {
41 let did = self.cx.tcx.hir.local_def_id(id);
42 self.get_blanket_impls(did, &def_ctor, Some(name))
46 pub fn get_blanket_impls<F>(
52 where F: Fn(DefId) -> Def {
53 let mut impls = Vec::new();
61 "get_blanket_impls(def_id={:?}, def_ctor=...): item has doc('hidden'), \
67 let ty = self.cx.tcx.type_of(def_id);
68 let generics = self.cx.tcx.generics_of(def_id);
69 let real_name = name.clone().map(|name| Ident::from_str(&name));
70 let param_env = self.cx.tcx.param_env(def_id);
71 for &trait_def_id in self.cx.all_traits.iter() {
72 if !self.cx.renderinfo.borrow().access_levels.is_doc_reachable(trait_def_id) ||
73 self.cx.generated_synthetics
75 .get(&(def_id, trait_def_id))
79 self.cx.tcx.for_each_relevant_impl(trait_def_id, ty, |impl_def_id| {
80 self.cx.tcx.infer_ctxt().enter(|infcx| {
81 let t_generics = infcx.tcx.generics_of(impl_def_id);
82 let trait_ref = infcx.tcx.impl_trait_ref(impl_def_id)
83 .expect("Cannot get impl trait");
85 match trait_ref.self_ty().sty {
90 let substs = infcx.fresh_substs_for_item(DUMMY_SP, def_id);
91 let ty = ty.subst(infcx.tcx, substs);
92 let param_env = param_env.subst(infcx.tcx, substs);
94 let impl_substs = infcx.fresh_substs_for_item(DUMMY_SP, impl_def_id);
95 let trait_ref = trait_ref.subst(infcx.tcx, impl_substs);
97 // Require the type the impl is implemented on to match
98 // our type, and ignore the impl if there was a mismatch.
99 let cause = traits::ObligationCause::dummy();
100 let eq_result = infcx.at(&cause, param_env)
101 .eq(trait_ref.self_ty(), ty);
102 if let Ok(InferOk { value: (), obligations }) = eq_result {
103 // FIXME(eddyb) ignoring `obligations` might cause false positives.
107 "invoking predicate_may_hold: {:?}",
110 let may_apply = match infcx.evaluate_obligation(
111 &traits::Obligation::new(
114 trait_ref.to_predicate(),
117 Ok(eval_result) => eval_result.may_apply(),
118 Err(traits::OverflowError) => true, // overflow doesn't mean yes *or* no
123 self.cx.generated_synthetics.borrow_mut()
124 .insert((def_id, trait_def_id));
125 let trait_ = hir::TraitRef {
126 path: get_path_for_type(infcx.tcx,
128 hir::def::Def::Trait),
129 ref_id: ast::DUMMY_NODE_ID,
130 hir_ref_id: hir::DUMMY_HIR_ID,
132 let provided_trait_methods =
133 infcx.tcx.provided_trait_methods(trait_def_id)
135 .map(|meth| meth.ident.to_string())
138 let ty = self.cx.get_real_ty(def_id, def_ctor, &real_name, generics);
139 let predicates = infcx.tcx.predicates_of(impl_def_id);
142 source: infcx.tcx.def_span(impl_def_id).clean(self.cx),
144 attrs: Default::default(),
146 def_id: self.cx.next_def_id(impl_def_id.krate),
149 inner: ImplItem(Impl {
150 unsafety: hir::Unsafety::Normal,
151 generics: (t_generics, &predicates).clean(self.cx),
152 provided_trait_methods,
153 trait_: Some(trait_.clean(self.cx)),
154 for_: ty.clean(self.cx),
155 items: infcx.tcx.associated_items(impl_def_id)
160 blanket_impl: Some(infcx.tcx.type_of(impl_def_id)