Clean generic impls code

src/librustdoc/clean/blanket_impl.rs

@@ -0,0 +1,170 @@
+// 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_ctor_from_def_id, get_def_ctor_from_node_id};
+use self::finder_trait::Finder;
+
+pub struct BlanketImplFinder<'a, 'tcx: 'a, 'rcx: 'a> {
+    pub cx: &'a core::DocContext<'a, 'tcx, 'rcx>,
+}
+
+impl<'a, 'tcx, 'rcx> BlanketImplFinder <'a, 'tcx, 'rcx> {
+    pub fn new(cx: &'a core::DocContext<'a, 'tcx, 'rcx>) -> Self {
+        BlanketImplFinder { cx }
+    }
+
+    pub fn get_with_def_id(&self, def_id: DefId) -> Vec<Item> {
+        get_def_ctor_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_ctor_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;
+        }
+        if self.cx.access_levels.borrow().is_doc_reachable(def_id) {
+            let generics = self.cx.tcx.generics_of(def_id);
+            let ty = self.cx.tcx.type_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 infcx.tcx.type_of(impl_def_id).sty {
+                            ::rustc::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.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.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)),
+                                }),
+                            });
+                            debug!("{:?} => {}", trait_ref, may_apply);
+                        }
+                    });
+                });
+            }
+        }
+        impls
+    }
+}
+
+impl<'a, 'tcx: 'a, 'rcx: 'a> Finder<'a, 'tcx, 'rcx> for BlanketImplFinder<'a, 'tcx, 'rcx> {
+    fn get_cx(&self) -> &DocContext<'a, 'tcx, 'rcx> {
+        &self.cx
+    }
+}

src/librustdoc/clean/def_ctor.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_ctor_from_def_id<F>(cx: &DocContext,
+                                   def_id: DefId,
+                                   callback: &F,
+) -> Vec<Item>
+where F: Fn(&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_ctor_from_node_id<F>(cx: &DocContext,
+                                    id: ast::NodeId,
+                                    name: String,
+                                    callback: &F,
+) -> Vec<Item>
+where F: Fn(&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/finder_trait.rs

@@ -0,0 +1,154 @@
+// 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 syntax_pos::DUMMY_SP;
+
+use super::*;
+
+pub trait Finder<'a, 'tcx: 'a, 'rcx: 'a> {
+    fn get_cx(&self) -> &DocContext<'a, 'tcx, 'rcx>;
+
+    // This is an ugly hack, but it's the simplest way to handle synthetic impls without greatly
+    // refactoring either librustdoc or librustc. In particular, allowing new DefIds to be
+    // registered after the AST is constructed would require storing the defid mapping in a
+    // RefCell, decreasing the performance for normal compilation for very little gain.
+    //
+    // Instead, we construct 'fake' def ids, which start immediately after the last DefId in
+    // DefIndexAddressSpace::Low. In the Debug impl for clean::Item, we explicitly check for fake
+    // def ids, as we'll end up with a panic if we use the DefId Debug impl for fake DefIds
+    fn next_def_id(&self, crate_num: CrateNum) -> DefId {
+        let start_def_id = {
+            let next_id = if crate_num == LOCAL_CRATE {
+                self.get_cx()
+                    .tcx
+                    .hir
+                    .definitions()
+                    .def_path_table()
+                    .next_id(DefIndexAddressSpace::Low)
+            } else {
+                self.get_cx()
+                    .cstore
+                    .def_path_table(crate_num)
+                    .next_id(DefIndexAddressSpace::Low)
+            };
+
+            DefId {
+                krate: crate_num,
+                index: next_id,
+            }
+        };
+
+        let mut fake_ids = self.get_cx().fake_def_ids.borrow_mut();
+
+        let def_id = fake_ids.entry(crate_num).or_insert(start_def_id).clone();
+        fake_ids.insert(
+            crate_num,
+            DefId {
+                krate: crate_num,
+                index: DefIndex::from_array_index(
+                    def_id.index.as_array_index() + 1,
+                    def_id.index.address_space(),
+                ),
+            },
+        );
+
+        MAX_DEF_ID.with(|m| {
+            m.borrow_mut()
+                .entry(def_id.krate.clone())
+                .or_insert(start_def_id);
+        });
+
+        self.get_cx().all_fake_def_ids.borrow_mut().insert(def_id);
+
+        def_id.clone()
+    }
+
+    fn get_real_ty<F>(&self,
+                      def_id: DefId,
+                      def_ctor: &F,
+                      real_name: &Option<Ident>,
+                      generics: &ty::Generics,
+    ) -> hir::Ty
+    where F: Fn(DefId) -> Def {
+        let path = get_path_for_type(self.get_cx().tcx, def_id, def_ctor);
+        let mut segments = path.segments.into_vec();
+        let last = segments.pop().expect("segments were empty");
+
+        segments.push(hir::PathSegment::new(
+            real_name.unwrap_or(last.ident),
+            self.generics_to_path_params(generics.clone()),
+            false,
+        ));
+
+        let new_path = hir::Path {
+            span: path.span,
+            def: path.def,
+            segments: HirVec::from_vec(segments),
+        };
+
+        hir::Ty {
+            id: ast::DUMMY_NODE_ID,
+            node: hir::TyKind::Path(hir::QPath::Resolved(None, P(new_path))),
+            span: DUMMY_SP,
+            hir_id: hir::DUMMY_HIR_ID,
+        }
+    }
+
+    fn generics_to_path_params(&self, generics: ty::Generics) -> hir::GenericArgs {
+        let mut args = vec![];
+
+        for param in generics.params.iter() {
+            match param.kind {
+                ty::GenericParamDefKind::Lifetime => {
+                    let name = if param.name == "" {
+                        hir::ParamName::Plain(keywords::StaticLifetime.ident())
+                    } else {
+                        hir::ParamName::Plain(ast::Ident::from_interned_str(param.name))
+                    };
+
+                    args.push(hir::GenericArg::Lifetime(hir::Lifetime {
+                        id: ast::DUMMY_NODE_ID,
+                        span: DUMMY_SP,
+                        name: hir::LifetimeName::Param(name),
+                    }));
+                }
+                ty::GenericParamDefKind::Type {..} => {
+                    args.push(hir::GenericArg::Type(self.ty_param_to_ty(param.clone())));
+                }
+            }
+        }
+
+        hir::GenericArgs {
+            args: HirVec::from_vec(args),
+            bindings: HirVec::new(),
+            parenthesized: false,
+        }
+    }
+
+    fn ty_param_to_ty(&self, param: ty::GenericParamDef) -> hir::Ty {
+        debug!("ty_param_to_ty({:?}) {:?}", param, param.def_id);
+        hir::Ty {
+            id: ast::DUMMY_NODE_ID,
+            node: hir::TyKind::Path(hir::QPath::Resolved(
+                None,
+                P(hir::Path {
+                    span: DUMMY_SP,
+                    def: Def::TyParam(param.def_id),
+                    segments: HirVec::from_vec(vec![
+                        hir::PathSegment::from_ident(Ident::from_interned_str(param.name))
+                    ]),
+                }),
+            )),
+            span: DUMMY_SP,
+            hir_id: hir::DUMMY_HIR_ID,
+        }
+    }
+}