Auto merge of #81349 - jyn514:blanket-impls-cleanup, r=lcnr

Remove unnecessary `self_ty` parameter to `get_blanket_impls`

It can be calculated when necessary at the callsite, there's no need to
pass it separately.

This also renames `param_env_def_id` to `item_def_id`.

cc `@eddyb`

src/librustdoc/clean/auto_trait.rs

@@ -34,7 +34,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
         ty: Ty<'tcx>,
         trait_def_id: DefId,
         param_env: ty::ParamEnv<'tcx>,
-        param_env_def_id: DefId,
+        item_def_id: DefId,
         f: &auto_trait::AutoTraitFinder<'tcx>,
         // If this is set, show only negative trait implementations, not positive ones.
         discard_positive_impl: bool,
@@ -50,7 +50,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
             let region_data = info.region_data;
 
             let names_map = tcx
-                .generics_of(param_env_def_id)
+                .generics_of(item_def_id)
                 .params
                 .iter()
                 .filter_map(|param| match param.kind {
@@ -62,16 +62,16 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
             let lifetime_predicates = Self::handle_lifetimes(&region_data, &names_map);
             let new_generics = self.param_env_to_generics(
                 infcx.tcx,
-                param_env_def_id,
+                item_def_id,
                 info.full_user_env,
                 lifetime_predicates,
                 info.vid_to_region,
             );
 
             debug!(
-                "find_auto_trait_generics(param_env_def_id={:?}, trait_def_id={:?}): \
+                "find_auto_trait_generics(item_def_id={:?}, trait_def_id={:?}): \
                     finished with {:?}",
-                param_env_def_id, trait_def_id, new_generics
+                item_def_id, trait_def_id, new_generics
             );
 
             new_generics
@@ -101,7 +101,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                 // Instead, we generate `impl !Send for Foo<T>`, which better
                 // expresses the fact that `Foo<T>` never implements `Send`,
                 // regardless of the choice of `T`.
-                let params = (tcx.generics_of(param_env_def_id), ty::GenericPredicates::default())
+                let params = (tcx.generics_of(item_def_id), ty::GenericPredicates::default())
                     .clean(self.cx)
                     .params;
 
@@ -115,7 +115,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
             name: None,
             attrs: Default::default(),
             visibility: Inherited,
-            def_id: self.cx.next_def_id(param_env_def_id.krate),
+            def_id: self.cx.next_def_id(item_def_id.krate),
             kind: box ImplItem(Impl {
                 unsafety: hir::Unsafety::Normal,
                 generics: new_generics,
@@ -130,26 +130,25 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
         })
     }
 
-    // FIXME(eddyb) figure out a better way to pass information about
-    // parametrization of `ty` than `param_env_def_id`.
-    crate fn get_auto_trait_impls(&mut self, ty: Ty<'tcx>, param_env_def_id: DefId) -> Vec<Item> {
+    crate fn get_auto_trait_impls(&mut self, item_def_id: DefId) -> Vec<Item> {
         let tcx = self.cx.tcx;
-        let param_env = tcx.param_env(param_env_def_id);
-        let f = auto_trait::AutoTraitFinder::new(self.cx.tcx);
+        let param_env = tcx.param_env(item_def_id);
+        let ty = tcx.type_of(item_def_id);
+        let f = auto_trait::AutoTraitFinder::new(tcx);
 
         debug!("get_auto_trait_impls({:?})", ty);
         let auto_traits: Vec<_> = self.cx.auto_traits.iter().cloned().collect();
         let mut auto_traits: Vec<Item> = auto_traits
             .into_iter()
             .filter_map(|trait_def_id| {
-                self.generate_for_trait(ty, trait_def_id, param_env, param_env_def_id, &f, false)
+                self.generate_for_trait(ty, trait_def_id, param_env, item_def_id, &f, false)
             })
             .collect();
         // We are only interested in case the type *doesn't* implement the Sized trait.
-        if !ty.is_sized(self.cx.tcx.at(rustc_span::DUMMY_SP), param_env) {
+        if !ty.is_sized(tcx.at(rustc_span::DUMMY_SP), param_env) {
             // In case `#![no_core]` is used, `sized_trait` returns nothing.
-            if let Some(item) = self.cx.tcx.lang_items().sized_trait().and_then(|sized_trait_did| {
-                self.generate_for_trait(ty, sized_trait_did, param_env, param_env_def_id, &f, true)
+            if let Some(item) = tcx.lang_items().sized_trait().and_then(|sized_trait_did| {
+                self.generate_for_trait(ty, sized_trait_did, param_env, item_def_id, &f, true)
             }) {
                 auto_traits.push(item);
             }
@@ -445,15 +444,15 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
     fn param_env_to_generics(
         &mut self,
         tcx: TyCtxt<'tcx>,
-        param_env_def_id: DefId,
+        item_def_id: DefId,
         param_env: ty::ParamEnv<'tcx>,
         mut existing_predicates: Vec<WherePredicate>,
         vid_to_region: FxHashMap<ty::RegionVid, ty::Region<'tcx>>,
     ) -> Generics {
         debug!(
-            "param_env_to_generics(param_env_def_id={:?}, param_env={:?}, \
+            "param_env_to_generics(item_def_id={:?}, param_env={:?}, \
              existing_predicates={:?})",
-            param_env_def_id, param_env, existing_predicates
+            item_def_id, param_env, existing_predicates
         );
 
         // The `Sized` trait must be handled specially, since we only display it when
@@ -463,7 +462,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
         let mut replacer = RegionReplacer { vid_to_region: &vid_to_region, tcx };
 
         let orig_bounds: FxHashSet<_> =
-            self.cx.tcx.param_env(param_env_def_id).caller_bounds().iter().collect();
+            self.cx.tcx.param_env(item_def_id).caller_bounds().iter().collect();
         let clean_where_predicates = param_env
             .caller_bounds()
             .iter()
@@ -477,14 +476,11 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
             .map(|p| p.fold_with(&mut replacer));
 
         let mut generic_params =
-            (tcx.generics_of(param_env_def_id), tcx.explicit_predicates_of(param_env_def_id))
+            (tcx.generics_of(item_def_id), tcx.explicit_predicates_of(item_def_id))
                 .clean(self.cx)
                 .params;
 
-        debug!(
-            "param_env_to_generics({:?}): generic_params={:?}",
-            param_env_def_id, generic_params
-        );
+        debug!("param_env_to_generics({:?}): generic_params={:?}", item_def_id, generic_params);
 
         let mut has_sized = FxHashSet::default();
         let mut ty_to_bounds: FxHashMap<_, FxHashSet<_>> = Default::default();
@@ -648,13 +644,10 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                                         .or_default()
                                         .insert(*trait_.clone());
                                 }
-                                _ => panic!(
-                                    "Unexpected trait {:?} for {:?}",
-                                    trait_, param_env_def_id,
-                                ),
+                                _ => panic!("Unexpected trait {:?} for {:?}", trait_, item_def_id),
                             }
                         }
-                        _ => panic!("Unexpected LHS {:?} for {:?}", lhs, param_env_def_id),
+                        _ => panic!("Unexpected LHS {:?} for {:?}", lhs, item_def_id),
                     }
                 }
             };

src/librustdoc/clean/blanket_impl.rs

@@ -14,10 +14,9 @@ crate struct BlanketImplFinder<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> {
-    // FIXME(eddyb) figure out a better way to pass information about
-    // parametrization of `ty` than `param_env_def_id`.
-    crate fn get_blanket_impls(&mut self, ty: Ty<'tcx>, param_env_def_id: DefId) -> Vec<Item> {
-        let param_env = self.cx.tcx.param_env(param_env_def_id);
+    crate fn get_blanket_impls(&mut self, item_def_id: DefId) -> Vec<Item> {
+        let param_env = self.cx.tcx.param_env(item_def_id);
+        let ty = self.cx.tcx.type_of(item_def_id);
 
         debug!("get_blanket_impls({:?})", ty);
         let mut impls = Vec::new();
@@ -39,7 +38,7 @@ impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> {
                         _ => return false,
                     }
 
-                    let substs = infcx.fresh_substs_for_item(DUMMY_SP, param_env_def_id);
+                    let substs = infcx.fresh_substs_for_item(DUMMY_SP, item_def_id);
                     let ty = ty.subst(infcx.tcx, substs);
                     let param_env = param_env.subst(infcx.tcx, substs);
 

src/librustdoc/clean/utils.rs

@@ -13,7 +13,7 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_middle::mir::interpret::ConstValue;
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
-use rustc_middle::ty::{self, DefIdTree, Ty, TyCtxt};
+use rustc_middle::ty::{self, DefIdTree, TyCtxt};
 use rustc_span::symbol::{kw, sym, Symbol};
 use std::mem;
 
@@ -426,19 +426,18 @@ crate fn resolve_type(cx: &mut DocContext<'_>, path: Path, id: hir::HirId) -> Ty
 
 crate fn get_auto_trait_and_blanket_impls(
     cx: &mut DocContext<'tcx>,
-    ty: Ty<'tcx>,
-    param_env_def_id: DefId,
+    item_def_id: DefId,
 ) -> impl Iterator<Item = Item> {
     let auto_impls = cx
         .sess()
         .prof
         .generic_activity("get_auto_trait_impls")
-        .run(|| AutoTraitFinder::new(cx).get_auto_trait_impls(ty, param_env_def_id));
+        .run(|| AutoTraitFinder::new(cx).get_auto_trait_impls(item_def_id));
     let blanket_impls = cx
         .sess()
         .prof
         .generic_activity("get_blanket_impls")
-        .run(|| BlanketImplFinder { cx }.get_blanket_impls(ty, param_env_def_id));
+        .run(|| BlanketImplFinder { cx }.get_blanket_impls(item_def_id));
     auto_impls.into_iter().chain(blanket_impls)
 }
 

src/librustdoc/passes/collect_trait_impls.rs

@@ -46,9 +46,7 @@ crate fn collect_trait_impls(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
 
                 // FIXME(eddyb) is this `doc(hidden)` check needed?
                 if !cx.tcx.get_attrs(def_id).lists(sym::doc).has_word(sym::hidden) {
-                    let self_ty = cx.tcx.type_of(def_id);
-                    let impls = get_auto_trait_and_blanket_impls(cx, self_ty, def_id);
-
+                    let impls = get_auto_trait_and_blanket_impls(cx, def_id);
                     new_items.extend(impls.filter(|i| cx.renderinfo.inlined.insert(i.def_id)));
                 }
             });
@@ -170,11 +168,7 @@ impl<'a, 'tcx> DocFolder for SyntheticImplCollector<'a, 'tcx> {
         if i.is_struct() || i.is_enum() || i.is_union() {
             // FIXME(eddyb) is this `doc(hidden)` check needed?
             if !self.cx.tcx.get_attrs(i.def_id).lists(sym::doc).has_word(sym::hidden) {
-                self.impls.extend(get_auto_trait_and_blanket_impls(
-                    self.cx,
-                    self.cx.tcx.type_of(i.def_id),
-                    i.def_id,
-                ));
+                self.impls.extend(get_auto_trait_and_blanket_impls(self.cx, i.def_id));
             }
         }