Auto merge of #52827 - GuillaumeGomez:generic-impls, r=QuietMisdreavus

rustdoc: clean up generic impls

r? @QuietMisdreavus

Author: bors

src/librustdoc/clean/auto_trait.rs

@@ -0,0 +1,162 @@
+// Copyright 2018 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 rustc::hir;
+use rustc::traits;
+use rustc::ty::ToPredicate;
+use rustc::ty::subst::Subst;
+use rustc::infer::InferOk;
+use syntax_pos::DUMMY_SP;
+
+use core::DocAccessLevels;
+
+use super::*;
+
+use self::def_ctor::{get_def_from_def_id, get_def_from_node_id};
+
+pub struct BlanketImplFinder<'a, 'tcx: 'a, 'rcx: 'a, 'cstore: 'rcx> {
+    pub cx: &'a core::DocContext<'a, 'tcx, 'rcx, 'cstore>,
+}
+
+impl<'a, 'tcx, 'rcx, 'cstore> BlanketImplFinder <'a, 'tcx, 'rcx, 'cstore> {
+    pub fn new(cx: &'a core::DocContext<'a, 'tcx, 'rcx, 'cstore>) -> Self {
+        BlanketImplFinder { cx }
+    }
+
+    pub fn get_with_def_id(&self, def_id: DefId) -> Vec<Item> {
+        get_def_from_def_id(&self.cx, def_id, &|def_ctor| {
+            self.get_blanket_impls(def_id, &def_ctor, None)
+        })
+    }
+
+    pub fn get_with_node_id(&self, id: ast::NodeId, name: String) -> Vec<Item> {
+        get_def_from_node_id(&self.cx, id, name, &|def_ctor, name| {
+            let did = self.cx.tcx.hir.local_def_id(id);
+            self.get_blanket_impls(did, &def_ctor, Some(name))
+        })
+    }
+
+    pub fn get_blanket_impls<F>(
+        &self,
+        def_id: DefId,
+        def_ctor: &F,
+        name: Option<String>,
+    ) -> Vec<Item>
+    where F: Fn(DefId) -> Def {
+        let mut impls = Vec::new();
+        if self.cx
+            .tcx
+            .get_attrs(def_id)
+            .lists("doc")
+            .has_word("hidden")
+        {
+            debug!(
+                "get_blanket_impls(def_id={:?}, def_ctor=...): item has doc('hidden'), \
+                 aborting",
+                def_id
+            );
+            return impls;
+        }
+        let ty = self.cx.tcx.type_of(def_id);
+        if self.cx.access_levels.borrow().is_doc_reachable(def_id) || ty.is_primitive() {
+            let generics = self.cx.tcx.generics_of(def_id);
+            let real_name = name.clone().map(|name| Ident::from_str(&name));
+            let param_env = self.cx.tcx.param_env(def_id);
+            for &trait_def_id in self.cx.all_traits.iter() {
+                if !self.cx.access_levels.borrow().is_doc_reachable(trait_def_id) ||
+                   self.cx.generated_synthetics
+                          .borrow_mut()
+                          .get(&(def_id, trait_def_id))
+                          .is_some() {
+                    continue
+                }
+                self.cx.tcx.for_each_relevant_impl(trait_def_id, ty, |impl_def_id| {
+                    self.cx.tcx.infer_ctxt().enter(|infcx| {
+                        let t_generics = infcx.tcx.generics_of(impl_def_id);
+                        let trait_ref = infcx.tcx.impl_trait_ref(impl_def_id)
+                                                 .expect("Cannot get impl trait");
+
+                        match trait_ref.self_ty().sty {
+                            ty::TypeVariants::TyParam(_) => {},
+                            _ => return,
+                        }
+
+                        let substs = infcx.fresh_substs_for_item(DUMMY_SP, def_id);
+                        let ty = ty.subst(infcx.tcx, substs);
+                        let param_env = param_env.subst(infcx.tcx, substs);
+
+                        let impl_substs = infcx.fresh_substs_for_item(DUMMY_SP, impl_def_id);
+                        let trait_ref = trait_ref.subst(infcx.tcx, impl_substs);
+
+                        // Require the type the impl is implemented on to match
+                        // our type, and ignore the impl if there was a mismatch.
+                        let cause = traits::ObligationCause::dummy();
+                        let eq_result = infcx.at(&cause, param_env)
+                                             .eq(trait_ref.self_ty(), ty);
+                        if let Ok(InferOk { value: (), obligations }) = eq_result {
+                            // FIXME(eddyb) ignoring `obligations` might cause false positives.
+                            drop(obligations);
+
+                            let may_apply = infcx.predicate_may_hold(&traits::Obligation::new(
+                                cause.clone(),
+                                param_env,
+                                trait_ref.to_predicate(),
+                            ));
+                            if !may_apply {
+                                return
+                            }
+                            self.cx.generated_synthetics.borrow_mut()
+                                                        .insert((def_id, trait_def_id));
+                            let trait_ = hir::TraitRef {
+                                path: get_path_for_type(infcx.tcx,
+                                                        trait_def_id,
+                                                        hir::def::Def::Trait),
+                                ref_id: ast::DUMMY_NODE_ID,
+                            };
+                            let provided_trait_methods =
+                                infcx.tcx.provided_trait_methods(trait_def_id)
+                                         .into_iter()
+                                         .map(|meth| meth.ident.to_string())
+                                         .collect();
+
+                            let ty = self.cx.get_real_ty(def_id, def_ctor, &real_name, generics);
+                            let predicates = infcx.tcx.predicates_of(impl_def_id);
+
+                            impls.push(Item {
+                                source: infcx.tcx.def_span(impl_def_id).clean(self.cx),
+                                name: None,
+                                attrs: Default::default(),
+                                visibility: None,
+                                def_id: self.cx.next_def_id(impl_def_id.krate),
+                                stability: None,
+                                deprecation: None,
+                                inner: ImplItem(Impl {
+                                    unsafety: hir::Unsafety::Normal,
+                                    generics: (t_generics, &predicates).clean(self.cx),
+                                    provided_trait_methods,
+                                    trait_: Some(trait_.clean(self.cx)),
+                                    for_: ty.clean(self.cx),
+                                    items: infcx.tcx.associated_items(impl_def_id)
+                                                    .collect::<Vec<_>>()
+                                                    .clean(self.cx),
+                                    polarity: None,
+                                    synthetic: false,
+                                    blanket_impl: Some(infcx.tcx.type_of(impl_def_id)
+                                                                .clean(self.cx)),
+                                }),
+                            });
+                        }
+                    });
+                });
+            }
+        }
+        impls
+    }
+}

src/librustdoc/clean/blanket_impl.rs

@@ -0,0 +1,65 @@
+// Copyright 2018 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 core::DocContext;
+
+use super::*;
+
+pub fn get_def_from_def_id<F>(cx: &DocContext,
+                              def_id: DefId,
+                              callback: &F,
+) -> Vec<Item>
+where F: Fn(& dyn Fn(DefId) -> Def) -> Vec<Item> {
+    let ty = cx.tcx.type_of(def_id);
+
+    match ty.sty {
+        ty::TyAdt(adt, _) => callback(&match adt.adt_kind() {
+            AdtKind::Struct => Def::Struct,
+            AdtKind::Enum => Def::Enum,
+            AdtKind::Union => Def::Union,
+        }),
+        ty::TyInt(_) |
+        ty::TyUint(_) |
+        ty::TyFloat(_) |
+        ty::TyStr |
+        ty::TyBool |
+        ty::TyChar => callback(&move |_: DefId| {
+            match ty.sty {
+                ty::TyInt(x) => Def::PrimTy(hir::TyInt(x)),
+                ty::TyUint(x) => Def::PrimTy(hir::TyUint(x)),
+                ty::TyFloat(x) => Def::PrimTy(hir::TyFloat(x)),
+                ty::TyStr => Def::PrimTy(hir::TyStr),
+                ty::TyBool => Def::PrimTy(hir::TyBool),
+                ty::TyChar => Def::PrimTy(hir::TyChar),
+                _ => unreachable!(),
+            }
+        }),
+        _ => {
+            debug!("Unexpected type {:?}", def_id);
+            Vec::new()
+        }
+    }
+}
+
+pub fn get_def_from_node_id<F>(cx: &DocContext,
+                               id: ast::NodeId,
+                               name: String,
+                               callback: &F,
+) -> Vec<Item>
+where F: Fn(& dyn Fn(DefId) -> Def, String) -> Vec<Item> {
+    let item = &cx.tcx.hir.expect_item(id).node;
+
+    callback(&match *item {
+        hir::ItemKind::Struct(_, _) => Def::Struct,
+        hir::ItemKind::Union(_, _) => Def::Union,
+        hir::ItemKind::Enum(_, _) => Def::Enum,
+        _ => panic!("Unexpected type {:?} {:?}", item, id),
+    }, name)
+}

src/librustdoc/clean/def_ctor.rs

@@ -25,7 +25,13 @@ use rustc::util::nodemap::FxHashSet;
 
 use core::{DocContext, DocAccessLevels};
 use doctree;
-use clean::{self, GetDefId, ToSource, get_auto_traits_with_def_id};
+use clean::{
+    self,
+    GetDefId,
+    ToSource,
+    get_auto_traits_with_def_id,
+    get_blanket_impls_with_def_id,
+};
 
 use super::Clean;
 
@@ -168,7 +174,7 @@ pub fn record_extern_fqn(cx: &DocContext, did: DefId, kind: clean::TypeKind) {
         }
     });
     let fqn = if let clean::TypeKind::Macro = kind {
-        vec![crate_name, relative.last().unwrap()]
+        vec![crate_name, relative.last().expect("relative was empty")]
     } else {
         once(crate_name).chain(relative).collect()
     };
@@ -274,11 +280,14 @@ pub fn build_impls(cx: &DocContext, did: DefId, auto_traits: bool) -> Vec<clean:
 
     if auto_traits {
         let auto_impls = get_auto_traits_with_def_id(cx, did);
-        let mut renderinfo = cx.renderinfo.borrow_mut();
-        let new_impls: Vec<clean::Item> = auto_impls.into_iter()
-            .filter(|i| renderinfo.inlined.insert(i.def_id)).collect();
+        {
+            let mut renderinfo = cx.renderinfo.borrow_mut();
+            let new_impls: Vec<clean::Item> = auto_impls.into_iter()
+                .filter(|i| renderinfo.inlined.insert(i.def_id)).collect();
 
-        impls.extend(new_impls);
+            impls.extend(new_impls);
+        }
+        impls.extend(get_blanket_impls_with_def_id(cx, did));
     }
 
     // If this is the first time we've inlined something from another crate, then
@@ -336,10 +345,13 @@ pub fn build_impls(cx: &DocContext, did: DefId, auto_traits: bool) -> Vec<clean:
             build_impl(cx, def_id, &mut impls);
 
             let auto_impls = get_auto_traits_with_def_id(cx, def_id);
+            let blanket_impls = get_blanket_impls_with_def_id(cx, def_id);
             let mut renderinfo = cx.renderinfo.borrow_mut();
 
             let new_impls: Vec<clean::Item> = auto_impls.into_iter()
-                .filter(|i| renderinfo.inlined.insert(i.def_id)).collect();
+                .chain(blanket_impls.into_iter())
+                .filter(|i| renderinfo.inlined.insert(i.def_id))
+                .collect();
 
             impls.extend(new_impls);
         }