From 6580f11a5239296d55c717fbe54fa2f71b861469 Mon Sep 17 00:00:00 2001 From: Joshua Nelson Date: Thu, 3 Dec 2020 20:14:11 -0500 Subject: [PATCH] Don't look for blanket impls in intra-doc links This never worked and has been causing severe performance problems. Hopefully it will be re-landed at some point in the future when it actually works, but in the meantime it makes no sense to have the code around when it does nothing and actively makes rustdoc harder to use. --- src/librustdoc/clean/types.rs | 11 +-- .../passes/collect_intra_doc_links.rs | 83 ++++--------------- 2 files changed, 15 insertions(+), 79 deletions(-) diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs index 2c353a1e0819e..699dbda32162c 100644 --- a/src/librustdoc/clean/types.rs +++ b/src/librustdoc/clean/types.rs @@ -21,7 +21,7 @@ use rustc_hir::def_id::{CrateNum, DefId}; use rustc_hir::lang_items::LangItem; use rustc_hir::Mutability; use rustc_index::vec::IndexVec; -use rustc_middle::ty::{AssocKind, TyCtxt}; +use rustc_middle::ty::TyCtxt; use rustc_session::Session; use rustc_span::hygiene::MacroKind; use rustc_span::source_map::DUMMY_SP; @@ -375,15 +375,6 @@ impl ItemKind { _ => false, } } - - crate fn as_assoc_kind(&self) -> Option { - match *self { - ItemKind::AssocConstItem(..) => Some(AssocKind::Const), - ItemKind::AssocTypeItem(..) => Some(AssocKind::Type), - ItemKind::TyMethodItem(..) | ItemKind::MethodItem(..) => Some(AssocKind::Fn), - _ => None, - } - } } #[derive(Clone, Debug)] diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs index dc6f8ed6cbbcd..f9d81fb863538 100644 --- a/src/librustdoc/passes/collect_intra_doc_links.rs +++ b/src/librustdoc/passes/collect_intra_doc_links.rs @@ -31,7 +31,7 @@ use std::cell::Cell; use std::mem; use std::ops::Range; -use crate::clean::{self, Crate, GetDefId, Item, ItemLink, PrimitiveType}; +use crate::clean::{self, Crate, Item, ItemLink, PrimitiveType}; use crate::core::DocContext; use crate::fold::DocFolder; use crate::html::markdown::markdown_links; @@ -685,78 +685,23 @@ fn resolve_associated_trait_item( ns: Namespace, cx: &DocContext<'_>, ) -> Option<(ty::AssocKind, DefId)> { - let ty = cx.tcx.type_of(did); - // First consider blanket impls: `impl From for T` - let implicit_impls = crate::clean::get_auto_trait_and_blanket_impls(cx, ty, did); - let mut candidates: Vec<_> = implicit_impls - .flat_map(|impl_outer| { - match impl_outer.kind { - clean::ImplItem(impl_) => { - debug!("considering auto or blanket impl for trait {:?}", impl_.trait_); - // Give precedence to methods that were overridden - if !impl_.provided_trait_methods.contains(&*item_name.as_str()) { - let mut items = impl_.items.into_iter().filter_map(|assoc| { - if assoc.name != Some(item_name) { - return None; - } - let kind = assoc - .kind - .as_assoc_kind() - .expect("inner items for a trait should be associated items"); - if kind.namespace() != ns { - return None; - } - - trace!("considering associated item {:?}", assoc.kind); - // We have a slight issue: normal methods come from `clean` types, - // but provided methods come directly from `tcx`. - // Fortunately, we don't need the whole method, we just need to know - // what kind of associated item it is. - Some((kind, assoc.def_id)) - }); - let assoc = items.next(); - debug_assert_eq!(items.count(), 0); - assoc - } else { - // These are provided methods or default types: - // ``` - // trait T { - // type A = usize; - // fn has_default() -> A { 0 } - // } - // ``` - let trait_ = impl_.trait_.unwrap().def_id().unwrap(); - cx.tcx - .associated_items(trait_) - .find_by_name_and_namespace( - cx.tcx, - Ident::with_dummy_span(item_name), - ns, - trait_, - ) - .map(|assoc| (assoc.kind, assoc.def_id)) - } - } - _ => panic!("get_impls returned something that wasn't an impl"), - } - }) - .collect(); + // FIXME: this should also consider blanket impls (`impl X for T`). Unfortunately + // `get_auto_trait_and_blanket_impls` is broken because the caching behavior is wrong. In the + // meantime, just don't look for these blanket impls. // Next consider explicit impls: `impl MyTrait for MyType` // Give precedence to inherent impls. - if candidates.is_empty() { - let traits = traits_implemented_by(cx, did, module); - debug!("considering traits {:?}", traits); - candidates.extend(traits.iter().filter_map(|&trait_| { - cx.tcx - .associated_items(trait_) - .find_by_name_and_namespace(cx.tcx, Ident::with_dummy_span(item_name), ns, trait_) - .map(|assoc| (assoc.kind, assoc.def_id)) - })); - } + let traits = traits_implemented_by(cx, did, module); + debug!("considering traits {:?}", traits); + let mut candidates = traits.iter().filter_map(|&trait_| { + cx.tcx + .associated_items(trait_) + .find_by_name_and_namespace(cx.tcx, Ident::with_dummy_span(item_name), ns, trait_) + .map(|assoc| (assoc.kind, assoc.def_id)) + }); // FIXME(#74563): warn about ambiguity - debug!("the candidates were {:?}", candidates); - candidates.pop() + debug!("the candidates were {:?}", candidates.clone().collect::>()); + candidates.next() } /// Given a type, return all traits in scope in `module` implemented by that type.