[rustdoc] Generic impls #52585
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -8,10 +8,15 @@ | ||
| // option. This file may not be copied, modified, or distributed | ||
| // except according to those terms. | ||
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| use rustc::hir; | ||
| use rustc::traits::{self, auto_trait as auto}; | ||
| use rustc::ty::{self, ToPredicate, TypeFoldable}; | ||
| use rustc::ty::subst::Subst; | ||
| use rustc::infer::InferOk; | ||
| use std::fmt::Debug; | ||
| use syntax_pos::DUMMY_SP; | ||
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| use core::DocAccessLevels; | ||
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| use super::*; | ||
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| @@ -75,6 +80,33 @@ impl<'a, 'tcx, 'rcx> AutoTraitFinder<'a, 'tcx, 'rcx> { | ||
| self.get_auto_trait_impls(did, &def_ctor, Some(name)) | ||
| } | ||
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| 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.cx.tcx, def_id, def_ctor); | ||
| let mut segments = path.segments.into_vec(); | ||
| let last = segments.pop().unwrap(); | ||
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| segments.push(hir::PathSegment::new( | ||
| real_name.unwrap_or(last.ident), | ||
| self.generics_to_path_params(generics.clone()), | ||
| false, | ||
| )); | ||
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| let new_path = hir::Path { | ||
| span: path.span, | ||
| def: path.def, | ||
| segments: HirVec::from_vec(segments), | ||
| }; | ||
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| 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, | ||
| } | ||
| } | ||
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| pub fn get_auto_trait_impls<F>( | ||
| &self, | ||
| def_id: DefId, | ||
| @@ -99,29 +131,126 @@ impl<'a, 'tcx, 'rcx> AutoTraitFinder<'a, 'tcx, 'rcx> { | ||
| let tcx = self.cx.tcx; | ||
| let generics = self.cx.tcx.generics_of(def_id); | ||
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| let ty = self.cx.tcx.type_of(def_id); | ||
| let mut traits = Vec::new(); | ||
| if self.cx.crate_name != Some("core".to_string()) && | ||
|
There was a problem hiding this comment. Why does this filter out libcore specifically? There was a problem hiding this comment. It panics getting There was a problem hiding this comment. Apparently, at some point since the original implementation, it doesn't panic if you take out this condition any more. I just tried it locally and it made everything just fine. |
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| self.cx.access_levels.borrow().is_doc_reachable(def_id) { | ||
| if let ty::TyAdt(_adt, _) = ty.sty { | ||
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There was a problem hiding this comment. why are we only doing this for adts? wouldn't it be practical to also see impls on tuples, array, slices, ...? There was a problem hiding this comment. True! But the answer lies on @eddyb side here. Or at least I recall him asking me to only perform this on |
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| 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) || | ||
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There was a problem hiding this comment. I think it would make sense to prefilter There was a problem hiding this comment. This is something I discussed a bit earlier with @QuietMisdreavus so I'll do it as well. There was a problem hiding this comment. Actually I can't, it depends on the context so we have to make this check in here ( |
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| 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 generics = infcx.tcx.generics_of(impl_def_id); | ||
| let trait_ref = infcx.tcx.impl_trait_ref(impl_def_id).unwrap(); | ||
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| if !match infcx.tcx.type_of(impl_def_id).sty { | ||
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There was a problem hiding this comment. match infcx.tcx.type_of(impl_def_id).sty {
::rustc::ty::TyParam(_) => {},
_ => return,
} |
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| ::rustc::ty::TypeVariants::TyParam(_) => true, | ||
| _ => false, | ||
| } { | ||
| return | ||
| } | ||
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| let substs = infcx.fresh_substs_for_item(DUMMY_SP, def_id); | ||
| let ty2 = ty.subst(infcx.tcx, substs); | ||
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There was a problem hiding this comment. we don't need both There was a problem hiding this comment. We do need |
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| let param_env = param_env.subst(infcx.tcx, substs); | ||
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| let impl_substs = infcx.fresh_substs_for_item(DUMMY_SP, impl_def_id); | ||
| let trait_ref = trait_ref.subst(infcx.tcx, impl_substs); | ||
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| // 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(), ty2); | ||
| if let Ok(InferOk { value: (), obligations }) = eq_result { | ||
| // FIXME(eddyb) ignoring `obligations` might cause false positives. | ||
| drop(obligations); | ||
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| 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() | ||
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There was a problem hiding this comment. couldn't we do this way earlier (like where we're early aborting usually) There was a problem hiding this comment. No because a trait can have multiple generic impls and we only know at this point that the current impl matches. |
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| .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(); | ||
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| let ty = self.get_real_ty(def_id, def_ctor, &real_name, generics); | ||
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| traits.push(Item { | ||
| source: Span::empty(), | ||
| 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: (generics, | ||
| &tcx.predicates_of(impl_def_id)).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: true, | ||
| }), | ||
| }); | ||
| debug!("{:?} => {}", trait_ref, may_apply); | ||
| } | ||
| }); | ||
| }); | ||
| } | ||
| } | ||
| } | ||
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| debug!( | ||
| "get_auto_trait_impls(def_id={:?}, def_ctor=..., generics={:?}", | ||
| def_id, generics | ||
| ); | ||
| let auto_traits: Vec<_> = | ||
| self.cx.send_trait | ||
|
There was a problem hiding this comment. that's some funky formatting here. revert this block? There was a problem hiding this comment. Just to double-check: i think @oli-obk wanted you to revert this section? There was a problem hiding this comment. Damn I thought I did! >< Might have been lost in my multiple tests... |
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| .and_then(|send_trait| { | ||
| self.get_auto_trait_impl_for( | ||
| def_id, | ||
| name.clone(), | ||
| generics.clone(), | ||
| def_ctor, | ||
| send_trait, | ||
| ) | ||
| }).into_iter() | ||
| .chain(self.get_auto_trait_impl_for( | ||
| def_id, | ||
| name.clone(), | ||
| generics.clone(), | ||
| def_ctor, | ||
| tcx.require_lang_item(lang_items::SyncTraitLangItem), | ||
| ).into_iter()) | ||
| .chain(traits.into_iter()) | ||
| .collect(); | ||
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| debug!( | ||
| @@ -196,31 +325,8 @@ impl<'a, 'tcx, 'rcx> AutoTraitFinder<'a, 'tcx, 'rcx> { | ||
| } | ||
| _ => unreachable!(), | ||
| }; | ||
| let real_name = name.map(|name| Ident::from_str(&name)); | ||
| let ty = self.get_real_ty(def_id, def_ctor, &real_name, &generics); | ||
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| return Some(Item { | ||
| source: Span::empty(), | ||
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -11,7 +11,7 @@ | ||
| use rustc_lint; | ||
| use rustc_driver::{self, driver, target_features, abort_on_err}; | ||
| use rustc::session::{self, config}; | ||
| use rustc::hir::def_id::{DefId, CrateNum, LOCAL_CRATE}; | ||
| use rustc::hir::def::Def; | ||
| use rustc::middle::cstore::CrateStore; | ||
| use rustc::middle::privacy::AccessLevels; | ||
| @@ -84,6 +84,7 @@ pub struct DocContext<'a, 'tcx: 'a, 'rcx: 'a> { | ||
| /// Maps (type_id, trait_id) -> auto trait impl | ||
| pub generated_synthetics: RefCell<FxHashSet<(DefId, DefId)>>, | ||
| pub current_item_name: RefCell<Option<Name>>, | ||
| pub all_traits: Vec<DefId>, | ||
| } | ||
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| impl<'a, 'tcx, 'rcx> DocContext<'a, 'tcx, 'rcx> { | ||
| @@ -385,6 +386,7 @@ pub fn run_core(search_paths: SearchPaths, | ||
| all_fake_def_ids: RefCell::new(FxHashSet()), | ||
| generated_synthetics: RefCell::new(FxHashSet()), | ||
| current_item_name: RefCell::new(None), | ||
| all_traits: tcx.all_traits(LOCAL_CRATE).to_vec(), | ||
|
There was a problem hiding this comment. I wonder if we can filter this down to just the ones with blanket impls? That may require some overhead here but would also cut down on the traits we iterate over when gathering impls. There was a problem hiding this comment. I'm not sure to understand you. I do this call here because it otherwise would need to be done on every item (and also because @eddyb thinks it's better this way, which I agree). There was a problem hiding this comment. Right, i understand why you wanted to cache the traits. I'm asking if it's possible to store less traits in this, by filtering out traits that don't have a blanket/generic impl. |
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| }; | ||
| debug!("crate: {:?}", tcx.hir.krate()); | ||
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,25 @@ | ||
| // 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. | ||
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| #![crate_name = "foo"] | ||
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| use std::fmt; | ||
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| // @!has foo/struct.Bar.html '//h3[@id="impl-ToString"]//code' 'impl<T> ToString for Bar' | ||
| pub struct Bar; | ||
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| // @has foo/struct.Foo.html '//h3[@id="impl-ToString"]//code' 'impl<T> ToString for Foo' | ||
| pub struct Foo; | ||
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| impl fmt::Display for Foo { | ||
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | ||
| write!(f, "Foo") | ||
| } | ||
| } |
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nit: this function signature should follow rustfmt block indent style (especially since it looks like the function below already follows that