Rollup of 7 pull requests

src/librustc_error_codes/error_codes/E0198.md

@@ -1,17 +1,18 @@
-A negative implementation is one that excludes a type from implementing a
-particular trait. Not being able to use a trait is always a safe operation,
-so negative implementations are always safe and never need to be marked as
-unsafe.
+A negative implementation was marked as unsafe.
 
-```compile_fail
-#![feature(optin_builtin_traits)]
+Erroneous code example:
 
+```compile_fail
 struct Foo;
 
-// unsafe is unnecessary
-unsafe impl !Clone for Foo { }
+unsafe impl !Clone for Foo { } // error!
 ```
 
+A negative implementation is one that excludes a type from implementing a
+particular trait. Not being able to use a trait is always a safe operation,
+so negative implementations are always safe and never need to be marked as
+unsafe.
+
 This will compile:
 
 ```ignore (ignore auto_trait future compatibility warning)

src/librustc_error_codes/error_codes/E0199.md

@@ -1,14 +1,23 @@
+A trait implementation was marked as unsafe while the trait is safe.
+
+Erroneous code example:
+
+```compile_fail,E0199
+struct Foo;
+
+trait Bar { }
+
+unsafe impl Bar for Foo { } // error!
+```
+
 Safe traits should not have unsafe implementations, therefore marking an
 implementation for a safe trait unsafe will cause a compiler error. Removing
-the unsafe marker on the trait noted in the error will resolve this problem.
+the unsafe marker on the trait noted in the error will resolve this problem:
 
-```compile_fail,E0199
+```
 struct Foo;
 
 trait Bar { }
 
-// this won't compile because Bar is safe
-unsafe impl Bar for Foo { }
-// this will compile
-impl Bar for Foo { }
+impl Bar for Foo { } // ok!
 ```

src/librustc_lint/nonstandard_style.rs

@@ -350,7 +350,20 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonSnakeCase {
     }
 
     fn check_pat(&mut self, cx: &LateContext<'_, '_>, p: &hir::Pat<'_>) {
-        if let &PatKind::Binding(_, _, ident, _) = &p.kind {
+        if let &PatKind::Binding(_, hid, ident, _) = &p.kind {
+            if let hir::Node::Pat(parent_pat) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid))
+            {
+                if let PatKind::Struct(_, field_pats, _) = &parent_pat.kind {
+                    for field in field_pats.iter() {
+                        if field.ident != ident {
+                            // Only check if a new name has been introduced, to avoid warning
+                            // on both the struct definition and this pattern.
+                            self.check_snake_case(cx, "variable", &ident);
+                        }
+                    }
+                    return;
+                }
+            }
             self.check_snake_case(cx, "variable", &ident);
         }
     }

src/librustc_mir/transform/qualify_min_const_fn.rs

@@ -309,21 +309,22 @@ fn check_terminator(
 ) -> McfResult {
     let span = terminator.source_info.span;
     match &terminator.kind {
-        TerminatorKind::Goto { .. } | TerminatorKind::Return | TerminatorKind::Resume => Ok(()),
+        TerminatorKind::FalseEdges { .. }
+        | TerminatorKind::FalseUnwind { .. }
+        | TerminatorKind::Goto { .. }
+        | TerminatorKind::Return
+        | TerminatorKind::Resume => Ok(()),
 
         TerminatorKind::Drop { location, .. } => check_place(tcx, location, span, def_id, body),
         TerminatorKind::DropAndReplace { location, value, .. } => {
             check_place(tcx, location, span, def_id, body)?;
             check_operand(tcx, value, span, def_id, body)
         }
 
-        TerminatorKind::FalseEdges { .. } | TerminatorKind::SwitchInt { .. }
-            if !feature_allowed(tcx, def_id, sym::const_if_match) =>
-        {
+        TerminatorKind::SwitchInt { .. } if !feature_allowed(tcx, def_id, sym::const_if_match) => {
             Err((span, "loops and conditional expressions are not stable in const fn".into()))
         }
 
-        TerminatorKind::FalseEdges { .. } => Ok(()),
         TerminatorKind::SwitchInt { discr, switch_ty: _, values: _, targets: _ } => {
             check_operand(tcx, discr, span, def_id, body)
         }
@@ -367,13 +368,5 @@ fn check_terminator(
         TerminatorKind::Assert { cond, expected: _, msg: _, target: _, cleanup: _ } => {
             check_operand(tcx, cond, span, def_id, body)
         }
-
-        TerminatorKind::FalseUnwind { .. } if feature_allowed(tcx, def_id, sym::const_loop) => {
-            Ok(())
-        }
-
-        TerminatorKind::FalseUnwind { .. } => {
-            Err((span, "loops are not allowed in const fn".into()))
-        }
     }
 }

src/librustdoc/clean/inline.rs

@@ -273,6 +273,22 @@ fn build_type_alias(cx: &DocContext<'_>, did: DefId) -> clean::Typedef {
     clean::Typedef {
         type_: cx.tcx.type_of(did).clean(cx),
         generics: (cx.tcx.generics_of(did), predicates).clean(cx),
+        item_type: build_type_alias_type(cx, did),
+    }
+}
+
+fn build_type_alias_type(cx: &DocContext<'_>, did: DefId) -> Option<clean::Type> {
+    let type_ = cx.tcx.type_of(did).clean(cx);
+    type_.def_id().and_then(|did| build_ty(cx, did))
+}
+
+pub fn build_ty(cx: &DocContext, did: DefId) -> Option<clean::Type> {
+    match cx.tcx.def_kind(did)? {
+        DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::Const | DefKind::Static => {
+            Some(cx.tcx.type_of(did).clean(cx))
+        }
+        DefKind::TyAlias => build_type_alias_type(cx, did),
+        _ => None,
     }
 }
 

src/librustdoc/clean/mod.rs

@@ -1122,7 +1122,9 @@ impl Clean<Item> for hir::ImplItem<'_> {
                 MethodItem((sig, &self.generics, body, Some(self.defaultness)).clean(cx))
             }
             hir::ImplItemKind::TyAlias(ref ty) => {
-                TypedefItem(Typedef { type_: ty.clean(cx), generics: Generics::default() }, true)
+                let type_ = ty.clean(cx);
+                let item_type = type_.def_id().and_then(|did| inline::build_ty(cx, did));
+                TypedefItem(Typedef { type_, generics: Generics::default(), item_type }, true)
             }
             hir::ImplItemKind::OpaqueTy(ref bounds) => OpaqueTyItem(
                 OpaqueTy { bounds: bounds.clean(cx), generics: Generics::default() },
@@ -1282,10 +1284,13 @@ impl Clean<Item> for ty::AssocItem {
 
                     AssocTypeItem(bounds, ty.clean(cx))
                 } else {
+                    let type_ = cx.tcx.type_of(self.def_id).clean(cx);
+                    let item_type = type_.def_id().and_then(|did| inline::build_ty(cx, did));
                     TypedefItem(
                         Typedef {
-                            type_: cx.tcx.type_of(self.def_id).clean(cx),
+                            type_,
                             generics: Generics { params: Vec::new(), where_predicates: Vec::new() },
+                            item_type,
                         },
                         true,
                     )
@@ -1989,6 +1994,8 @@ impl Clean<String> for ast::Name {
 
 impl Clean<Item> for doctree::Typedef<'_> {
     fn clean(&self, cx: &DocContext<'_>) -> Item {
+        let type_ = self.ty.clean(cx);
+        let item_type = type_.def_id().and_then(|did| inline::build_ty(cx, did));
         Item {
             name: Some(self.name.clean(cx)),
             attrs: self.attrs.clean(cx),
@@ -1997,10 +2004,7 @@ impl Clean<Item> for doctree::Typedef<'_> {
             visibility: self.vis.clean(cx),
             stability: cx.stability(self.id).clean(cx),
             deprecation: cx.deprecation(self.id).clean(cx),
-            inner: TypedefItem(
-                Typedef { type_: self.ty.clean(cx), generics: self.gen.clean(cx) },
-                false,
-            ),
+            inner: TypedefItem(Typedef { type_, generics: self.gen.clean(cx), item_type }, false),
         }
     }
 }
@@ -2101,7 +2105,7 @@ impl Clean<Vec<Item>> for doctree::Impl<'_> {
             build_deref_target_impls(cx, &items, &mut ret);
         }
 
-        let provided = trait_
+        let provided: FxHashSet<String> = trait_
             .def_id()
             .map(|did| {
                 cx.tcx
@@ -2112,7 +2116,12 @@ impl Clean<Vec<Item>> for doctree::Impl<'_> {
             })
             .unwrap_or_default();
 
-        ret.push(Item {
+        let for_ = self.for_.clean(cx);
+        let type_alias = for_.def_id().and_then(|did| match cx.tcx.def_kind(did) {
+            Some(DefKind::TyAlias) => Some(cx.tcx.type_of(did).clean(cx)),
+            _ => None,
+        });
+        let make_item = |trait_: Option<Type>, for_: Type, items: Vec<Item>| Item {
             name: None,
             attrs: self.attrs.clean(cx),
             source: self.whence.clean(cx),
@@ -2123,15 +2132,19 @@ impl Clean<Vec<Item>> for doctree::Impl<'_> {
             inner: ImplItem(Impl {
                 unsafety: self.unsafety,
                 generics: self.generics.clean(cx),
-                provided_trait_methods: provided,
+                provided_trait_methods: provided.clone(),
                 trait_,
-                for_: self.for_.clean(cx),
+                for_,
                 items,
                 polarity: Some(cx.tcx.impl_polarity(def_id).clean(cx)),
                 synthetic: false,
                 blanket_impl: None,
             }),
-        });
+        };
+        if let Some(type_alias) = type_alias {
+            ret.push(make_item(trait_.clone(), type_alias, items.clone()));
+        }
+        ret.push(make_item(trait_, for_, items));
         ret
     }
 }

src/librustdoc/clean/types.rs

@@ -1406,6 +1406,14 @@ pub struct PathSegment {
 pub struct Typedef {
     pub type_: Type,
     pub generics: Generics,
+    // Type of target item.
+    pub item_type: Option<Type>,
+}
+
+impl GetDefId for Typedef {
+    fn def_id(&self) -> Option<DefId> {
+        self.type_.def_id()
+    }
 }
 
 #[derive(Clone, Debug)]

src/librustdoc/html/render.rs

@@ -3469,20 +3469,23 @@ fn render_deref_methods(
     deref_mut: bool,
 ) {
     let deref_type = impl_.inner_impl().trait_.as_ref().unwrap();
-    let target = impl_
+    let (target, real_target) = impl_
         .inner_impl()
         .items
         .iter()
         .filter_map(|item| match item.inner {
-            clean::TypedefItem(ref t, true) => Some(&t.type_),
+            clean::TypedefItem(ref t, true) => Some(match *t {
+                clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
+                _ => (&t.type_, &t.type_),
+            }),
             _ => None,
         })
         .next()
         .expect("Expected associated type binding");
     let what =
-        AssocItemRender::DerefFor { trait_: deref_type, type_: target, deref_mut_: deref_mut };
+        AssocItemRender::DerefFor { trait_: deref_type, type_: real_target, deref_mut_: deref_mut };
     if let Some(did) = target.def_id() {
-        render_assoc_items(w, cx, container_item, did, what)
+        render_assoc_items(w, cx, container_item, did, what);
     } else {
         if let Some(prim) = target.primitive_type() {
             if let Some(&did) = cx.cache.primitive_locations.get(&prim) {
@@ -4123,12 +4126,15 @@ fn sidebar_assoc_items(it: &clean::Item) -> String {
                 .filter(|i| i.inner_impl().trait_.is_some())
                 .find(|i| i.inner_impl().trait_.def_id() == c.deref_trait_did)
             {
-                if let Some(target) = impl_
+                if let Some((target, real_target)) = impl_
                     .inner_impl()
                     .items
                     .iter()
                     .filter_map(|item| match item.inner {
-                        clean::TypedefItem(ref t, true) => Some(&t.type_),
+                        clean::TypedefItem(ref t, true) => Some(match *t {
+                            clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
+                            _ => (&t.type_, &t.type_),
+                        }),
                         _ => None,
                     })
                     .next()
@@ -4147,7 +4153,7 @@ fn sidebar_assoc_items(it: &clean::Item) -> String {
                                 "{:#}",
                                 impl_.inner_impl().trait_.as_ref().unwrap().print()
                             )),
-                            Escape(&format!("{:#}", target.print()))
+                            Escape(&format!("{:#}", real_target.print()))
                         ));
                         out.push_str("</a>");
                         let mut ret = impls

src/librustdoc/html/render/cache.rs

@@ -277,7 +277,7 @@ impl DocFolder for Cache {
                 | clean::StructFieldItem(..)
                 | clean::VariantItem(..) => (
                     (
-                        Some(*self.parent_stack.last().unwrap()),
+                        Some(*self.parent_stack.last().expect("parent_stack is empty")),
                         Some(&self.stack[..self.stack.len() - 1]),
                     ),
                     false,
@@ -286,7 +286,7 @@ impl DocFolder for Cache {
                     if self.parent_stack.is_empty() {
                         ((None, None), false)
                     } else {
-                        let last = self.parent_stack.last().unwrap();
+                        let last = self.parent_stack.last().expect("parent_stack is empty 2");
                         let did = *last;
                         let path = match self.paths.get(&did) {
                             // The current stack not necessarily has correlation
@@ -468,7 +468,7 @@ impl DocFolder for Cache {
                         self.impls.entry(did).or_insert(vec![]).push(impl_item.clone());
                     }
                 } else {
-                    let trait_did = impl_item.trait_did().unwrap();
+                    let trait_did = impl_item.trait_did().expect("no trait did");
                     self.orphan_trait_impls.push((trait_did, dids, impl_item));
                 }
                 None
@@ -478,10 +478,10 @@ impl DocFolder for Cache {
         });
 
         if pushed {
-            self.stack.pop().unwrap();
+            self.stack.pop().expect("stack already empty");
         }
         if parent_pushed {
-            self.parent_stack.pop().unwrap();
+            self.parent_stack.pop().expect("parent stack already empty");
         }
         self.stripped_mod = orig_stripped_mod;
         self.parent_is_trait_impl = orig_parent_is_trait_impl;
@@ -594,7 +594,7 @@ fn build_index(krate: &clean::Crate, cache: &mut Cache) -> String {
     for item in search_index {
         item.parent_idx = item.parent.map(|nodeid| {
             if nodeid_to_pathid.contains_key(&nodeid) {
-                *nodeid_to_pathid.get(&nodeid).unwrap()
+                *nodeid_to_pathid.get(&nodeid).expect("no pathid")
             } else {
                 let pathid = lastpathid;
                 nodeid_to_pathid.insert(nodeid, pathid);
@@ -639,7 +639,7 @@ fn build_index(krate: &clean::Crate, cache: &mut Cache) -> String {
             items: crate_items,
             paths: crate_paths,
         })
-        .unwrap()
+        .expect("failed serde conversion")
     )
 }