Auto merge of #9257 - flip1995:rustup, r=flip1995

Rustup

r? `@ghost`

changelog: none

Author: bors

clippy_dev/src/lib.rs

@@ -1,4 +1,3 @@
-#![feature(let_chains)]
 #![feature(let_else)]
 #![feature(once_cell)]
 #![feature(rustc_private)]

clippy_lints/src/format.rs

@@ -82,7 +82,7 @@ impl<'tcx> LateLintPass<'tcx> for UselessFormat {
                 then {
                     let is_new_string = match value.kind {
                         ExprKind::Binary(..) => true,
-                        ExprKind::MethodCall(path, ..) => path.ident.name.as_str() == "to_string",
+                        ExprKind::MethodCall(path, ..) => path.ident.name == sym::to_string,
                         _ => false,
                     };
                     let sugg = if is_new_string {

clippy_lints/src/format_impl.rs

@@ -141,7 +141,7 @@ fn check_to_string_in_display(cx: &LateContext<'_>, expr: &Expr<'_>) {
         // Get the hir_id of the object we are calling the method on
         if let ExprKind::MethodCall(path, [ref self_arg, ..], _) = expr.kind;
         // Is the method to_string() ?
-        if path.ident.name == sym!(to_string);
+        if path.ident.name == sym::to_string;
         // Is the method a part of the ToString trait? (i.e. not to_string() implemented
         // separately)
         if let Some(expr_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);

clippy_lints/src/inherent_to_string.rs

@@ -98,7 +98,7 @@ impl<'tcx> LateLintPass<'tcx> for InherentToString {
         if_chain! {
             // Check if item is a method, called to_string and has a parameter 'self'
             if let ImplItemKind::Fn(ref signature, _) = impl_item.kind;
-            if impl_item.ident.name.as_str() == "to_string";
+            if impl_item.ident.name == sym::to_string;
             let decl = &signature.decl;
             if decl.implicit_self.has_implicit_self();
             if decl.inputs.len() == 1;

clippy_lints/src/lib.rs

@@ -4,7 +4,6 @@
 #![feature(control_flow_enum)]
 #![feature(drain_filter)]
 #![feature(iter_intersperse)]
-#![feature(let_chains)]
 #![feature(let_else)]
 #![feature(lint_reasons)]
 #![feature(never_type)]

clippy_lints/src/lifetimes.rs

@@ -9,12 +9,14 @@ use rustc_hir::intravisit::{
 use rustc_hir::FnRetTy::Return;
 use rustc_hir::{
     BareFnTy, BodyId, FnDecl, GenericArg, GenericBound, GenericParam, GenericParamKind, Generics, Impl, ImplItem,
-    ImplItemKind, Item, ItemKind, LangItem, Lifetime, LifetimeName, LifetimeParamKind, ParamName, PolyTraitRef,
-    PredicateOrigin, TraitBoundModifier, TraitFn, TraitItem, TraitItemKind, Ty, TyKind, WherePredicate,
+    ImplItemKind, Item, ItemKind, LangItem, Lifetime, LifetimeName, ParamName, PolyTraitRef, PredicateOrigin,
+    TraitBoundModifier, TraitFn, TraitItem, TraitItemKind, Ty, TyKind, WherePredicate,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter as middle_nested_filter;
+use rustc_middle::ty::TyCtxt;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::symbol::{kw, Ident, Symbol};
 
@@ -129,7 +131,7 @@ impl<'tcx> LateLintPass<'tcx> for Lifetimes {
 enum RefLt {
     Unnamed,
     Static,
-    Named(Symbol),
+    Named(LocalDefId),
 }
 
 fn check_fn_inner<'tcx>(
@@ -232,7 +234,7 @@ fn could_use_elision<'tcx>(
     // level of the current item.
 
     // check named LTs
-    let allowed_lts = allowed_lts_from(named_generics);
+    let allowed_lts = allowed_lts_from(cx.tcx, named_generics);
 
     // these will collect all the lifetimes for references in arg/return types
     let mut input_visitor = RefVisitor::new(cx);
@@ -254,22 +256,6 @@ fn could_use_elision<'tcx>(
         return false;
     }
 
-    if allowed_lts
-        .intersection(
-            &input_visitor
-                .nested_elision_site_lts
-                .iter()
-                .chain(output_visitor.nested_elision_site_lts.iter())
-                .cloned()
-                .filter(|v| matches!(v, RefLt::Named(_)))
-                .collect(),
-        )
-        .next()
-        .is_some()
-    {
-        return false;
-    }
-
     let input_lts = input_visitor.lts;
     let output_lts = output_visitor.lts;
 
@@ -303,6 +289,31 @@ fn could_use_elision<'tcx>(
         }
     }
 
+    // check for higher-ranked trait bounds
+    if !input_visitor.nested_elision_site_lts.is_empty() || !output_visitor.nested_elision_site_lts.is_empty() {
+        let allowed_lts: FxHashSet<_> = allowed_lts
+            .iter()
+            .filter_map(|lt| match lt {
+                RefLt::Named(def_id) => Some(cx.tcx.item_name(def_id.to_def_id())),
+                _ => None,
+            })
+            .collect();
+        for lt in input_visitor.nested_elision_site_lts {
+            if let RefLt::Named(def_id) = lt {
+                if allowed_lts.contains(&cx.tcx.item_name(def_id.to_def_id())) {
+                    return false;
+                }
+            }
+        }
+        for lt in output_visitor.nested_elision_site_lts {
+            if let RefLt::Named(def_id) = lt {
+                if allowed_lts.contains(&cx.tcx.item_name(def_id.to_def_id())) {
+                    return false;
+                }
+            }
+        }
+    }
+
     // no input lifetimes? easy case!
     if input_lts.is_empty() {
         false
@@ -335,14 +346,11 @@ fn could_use_elision<'tcx>(
     }
 }
 
-fn allowed_lts_from(named_generics: &[GenericParam<'_>]) -> FxHashSet<RefLt> {
+fn allowed_lts_from(tcx: TyCtxt<'_>, named_generics: &[GenericParam<'_>]) -> FxHashSet<RefLt> {
     let mut allowed_lts = FxHashSet::default();
     for par in named_generics.iter() {
-        if let GenericParamKind::Lifetime {
-            kind: LifetimeParamKind::Explicit,
-        } = par.kind
-        {
-            allowed_lts.insert(RefLt::Named(par.name.ident().name));
+        if let GenericParamKind::Lifetime { .. } = par.kind {
+            allowed_lts.insert(RefLt::Named(tcx.hir().local_def_id(par.hir_id)));
         }
     }
     allowed_lts.insert(RefLt::Unnamed);
@@ -385,8 +393,10 @@ impl<'a, 'tcx> RefVisitor<'a, 'tcx> {
                 self.lts.push(RefLt::Unnamed);
             } else if lt.is_elided() {
                 self.lts.push(RefLt::Unnamed);
+            } else if let LifetimeName::Param(def_id, _) = lt.name {
+                self.lts.push(RefLt::Named(def_id));
             } else {
-                self.lts.push(RefLt::Named(lt.name.ident().name));
+                self.lts.push(RefLt::Unnamed);
             }
         } else {
             self.lts.push(RefLt::Unnamed);
@@ -434,18 +444,22 @@ impl<'a, 'tcx> Visitor<'tcx> for RefVisitor<'a, 'tcx> {
             TyKind::OpaqueDef(item, bounds) => {
                 let map = self.cx.tcx.hir();
                 let item = map.item(item);
+                let len = self.lts.len();
                 walk_item(self, item);
-                walk_ty(self, ty);
+                self.lts.truncate(len);
                 self.lts.extend(bounds.iter().filter_map(|bound| match bound {
-                    GenericArg::Lifetime(l) => Some(RefLt::Named(l.name.ident().name)),
+                    GenericArg::Lifetime(l) => Some(if let LifetimeName::Param(def_id, _) = l.name {
+                        RefLt::Named(def_id)
+                    } else {
+                        RefLt::Unnamed
+                    }),
                     _ => None,
                 }));
             },
             TyKind::BareFn(&BareFnTy { decl, .. }) => {
                 let mut sub_visitor = RefVisitor::new(self.cx);
                 sub_visitor.visit_fn_decl(decl);
                 self.nested_elision_site_lts.append(&mut sub_visitor.all_lts());
-                return;
             },
             TyKind::TraitObject(bounds, ref lt, _) => {
                 if !lt.is_elided() {
@@ -454,11 +468,9 @@ impl<'a, 'tcx> Visitor<'tcx> for RefVisitor<'a, 'tcx> {
                 for bound in bounds {
                     self.visit_poly_trait_ref(bound, TraitBoundModifier::None);
                 }
-                return;
             },
-            _ => (),
+            _ => walk_ty(self, ty),
         }
-        walk_ty(self, ty);
     }
 }
 
@@ -477,7 +489,7 @@ fn has_where_lifetimes<'tcx>(cx: &LateContext<'tcx>, generics: &'tcx Generics<'_
                     return true;
                 }
                 // if the bounds define new lifetimes, they are fine to occur
-                let allowed_lts = allowed_lts_from(pred.bound_generic_params);
+                let allowed_lts = allowed_lts_from(cx.tcx, pred.bound_generic_params);
                 // now walk the bounds
                 for bound in pred.bounds.iter() {
                     walk_param_bound(&mut visitor, bound);
@@ -601,7 +613,7 @@ struct BodyLifetimeChecker {
 impl<'tcx> Visitor<'tcx> for BodyLifetimeChecker {
     // for lifetimes as parameters of generics
     fn visit_lifetime(&mut self, lifetime: &'tcx Lifetime) {
-        if lifetime.name.ident().name != kw::Empty && lifetime.name.ident().name != kw::StaticLifetime {
+        if lifetime.name.ident().name != kw::UnderscoreLifetime && lifetime.name.ident().name != kw::StaticLifetime {
             self.lifetimes_used_in_body = true;
         }
     }

clippy_lints/src/manual_async_fn.rs

@@ -166,7 +166,7 @@ fn captures_all_lifetimes(inputs: &[Ty<'_>], output_lifetimes: &[LifetimeName])
     // - There's only one output lifetime bound using `+ '_`
     // - All input lifetimes are explicitly bound to the output
     input_lifetimes.is_empty()
-        || (output_lifetimes.len() == 1 && matches!(output_lifetimes[0], LifetimeName::Underscore))
+        || (output_lifetimes.len() == 1 && matches!(output_lifetimes[0], LifetimeName::Infer))
         || input_lifetimes
             .iter()
             .all(|in_lt| output_lifetimes.iter().any(|out_lt| in_lt == out_lt))

clippy_lints/src/methods/inefficient_to_string.rs

@@ -14,7 +14,7 @@ use super::INEFFICIENT_TO_STRING;
 /// Checks for the `INEFFICIENT_TO_STRING` lint
 pub fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, method_name: Symbol, args: &[hir::Expr<'_>]) {
     if_chain! {
-        if args.len() == 1 && method_name == sym!(to_string);
+        if args.len() == 1 && method_name == sym::to_string;
         if let Some(to_string_meth_did) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if match_def_path(cx, to_string_meth_did, &paths::TO_STRING_METHOD);
         if let Some(substs) = cx.typeck_results().node_substs_opt(expr.hir_id);

clippy_lints/src/methods/unnecessary_to_owned.rs

@@ -427,5 +427,5 @@ fn is_cow_into_owned(cx: &LateContext<'_>, method_name: Symbol, method_def_id: D
 
 /// Returns true if the named method is `ToString::to_string`.
 fn is_to_string(cx: &LateContext<'_>, method_name: Symbol, method_def_id: DefId) -> bool {
-    method_name.as_str() == "to_string" && is_diag_trait_item(cx, method_def_id, sym::ToString)
+    method_name == sym::to_string && is_diag_trait_item(cx, method_def_id, sym::ToString)
 }

clippy_lints/src/ptr.rs

@@ -351,7 +351,7 @@ impl fmt::Display for RefPrefix {
                 name.fmt(f)?;
                 f.write_char(' ')?;
             },
-            LifetimeName::Underscore => f.write_str("'_ ")?,
+            LifetimeName::Infer => f.write_str("'_ ")?,
             LifetimeName::Static => f.write_str("'static ")?,
             _ => (),
         }