Auto merge of #64814 - Mark-Simulacrum:beta-next, r=Mark-Simulacrum

[beta] switch to stable bootstrap and rollup backports

Contains the following:

* Account for the Zero sub-pattern case. #64748
* relnotes: make compatibility section more sterile and fix rustc version #64742
* Rustdoc render async function re-export #64599
* Update cargo #64773
* switches us to stable bootstrap (not dev-static) (no PR)

Author: bors

RELEASES.md

@@ -70,10 +70,10 @@ Misc
 
 Compatibility Notes
 -------------------
-- Unfortunately the [`x86_64-unknown-uefi` platform can not be built][62785]
-  with rustc 1.39.0.
-- The [`armv7-unknown-linux-gnueabihf` platform is also known to have
-  issues][62896] for certain crates such as libc.
+- The [`x86_64-unknown-uefi` platform can not be built][62785] with rustc
+  1.38.0.
+- The [`armv7-unknown-linux-gnueabihf` platform is known to have
+  issues][62896] with certain crates such as libc.
 
 [60260]: https://github.com/rust-lang/rust/pull/60260/
 [61457]: https://github.com/rust-lang/rust/pull/61457/

src/librustc/query/mod.rs

@@ -244,6 +244,10 @@ rustc_queries! {
             desc { |tcx| "checking if item is const fn: `{}`", tcx.def_path_str(key) }
         }
 
+        query asyncness(key: DefId) -> hir::IsAsync {
+            desc { |tcx| "checking if the function is async: `{}`", tcx.def_path_str(key) }
+        }
+
         /// Returns `true` if calls to the function may be promoted.
         ///
         /// This is either because the function is e.g., a tuple-struct or tuple-variant

src/librustc/ty/mod.rs

@@ -3353,13 +3353,30 @@ fn issue33140_self_ty(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Ty<'_>> {
     }
 }
 
+/// Check if a function is async.
+fn asyncness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::IsAsync {
+    let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap_or_else(|| {
+        bug!("asyncness: expected local `DefId`, got `{:?}`", def_id)
+    });
+
+    let node = tcx.hir().get(hir_id);
+
+    let fn_like = hir::map::blocks::FnLikeNode::from_node(node).unwrap_or_else(|| {
+        bug!("asyncness: expected fn-like node but got `{:?}`", def_id);
+    });
+
+    fn_like.asyncness()
+}
+
+
 pub fn provide(providers: &mut ty::query::Providers<'_>) {
     context::provide(providers);
     erase_regions::provide(providers);
     layout::provide(providers);
     util::provide(providers);
     constness::provide(providers);
     *providers = ty::query::Providers {
+        asyncness,
         associated_item,
         associated_item_def_ids,
         adt_sized_constraint,

src/librustc_metadata/cstore_impl.rs

@@ -133,6 +133,7 @@ provide! { <'tcx> tcx, def_id, other, cdata,
     fn_sig => { cdata.fn_sig(def_id.index, tcx) }
     inherent_impls => { cdata.get_inherent_implementations_for_type(tcx, def_id.index) }
     is_const_fn_raw => { cdata.is_const_fn_raw(def_id.index) }
+    asyncness => { cdata.asyncness(def_id.index) }
     is_foreign_item => { cdata.is_foreign_item(def_id.index) }
     static_mutability => { cdata.static_mutability(def_id.index) }
     def_kind => { cdata.def_kind(def_id.index) }

src/librustc_metadata/decoder.rs

@@ -1212,6 +1212,15 @@ impl<'a, 'tcx> CrateMetadata {
         constness == hir::Constness::Const
     }
 
+    pub fn asyncness(&self, id: DefIndex) -> hir::IsAsync {
+         match self.entry(id).kind {
+            EntryKind::Fn(data) => data.decode(self).asyncness,
+            EntryKind::Method(data) => data.decode(self).fn_data.asyncness,
+            EntryKind::ForeignFn(data) => data.decode(self).asyncness,
+            _ => bug!("asyncness: expect functions entry."),
+        }
+    }
+
     pub fn is_foreign_item(&self, id: DefIndex) -> bool {
         match self.entry(id).kind {
             EntryKind::ForeignImmStatic |

src/librustc_metadata/encoder.rs

@@ -875,7 +875,7 @@ impl EncodeContext<'tcx> {
                 EntryKind::AssocConst(container, const_qualif, rendered_const)
             }
             ty::AssocKind::Method => {
-                let fn_data = if let hir::TraitItemKind::Method(_, ref m) = ast_item.node {
+                let fn_data = if let hir::TraitItemKind::Method(method_sig, m) = &ast_item.node {
                     let param_names = match *m {
                         hir::TraitMethod::Required(ref names) => {
                             self.encode_fn_param_names(names)
@@ -885,6 +885,7 @@ impl EncodeContext<'tcx> {
                         }
                     };
                     FnData {
+                        asyncness: method_sig.header.asyncness,
                         constness: hir::Constness::NotConst,
                         param_names,
                         sig: self.lazy(&tcx.fn_sig(def_id)),
@@ -982,6 +983,7 @@ impl EncodeContext<'tcx> {
             ty::AssocKind::Method => {
                 let fn_data = if let hir::ImplItemKind::Method(ref sig, body) = ast_item.node {
                     FnData {
+                        asyncness: sig.header.asyncness,
                         constness: sig.header.constness,
                         param_names: self.encode_fn_param_names_for_body(body),
                         sig: self.lazy(&tcx.fn_sig(def_id)),
@@ -1128,6 +1130,7 @@ impl EncodeContext<'tcx> {
             }
             hir::ItemKind::Fn(_, header, .., body) => {
                 let data = FnData {
+                    asyncness: header.asyncness,
                     constness: header.constness,
                     param_names: self.encode_fn_param_names_for_body(body),
                     sig: self.lazy(tcx.fn_sig(def_id)),
@@ -1675,6 +1678,7 @@ impl EncodeContext<'tcx> {
         let kind = match nitem.node {
             hir::ForeignItemKind::Fn(_, ref names, _) => {
                 let data = FnData {
+                    asyncness: hir::IsAsync::NotAsync,
                     constness: hir::Constness::NotConst,
                     param_names: self.encode_fn_param_names(names),
                     sig: self.lazy(tcx.fn_sig(def_id)),

src/librustc_metadata/schema.rs

@@ -295,6 +295,7 @@ pub struct MacroDef {
 
 #[derive(RustcEncodable, RustcDecodable)]
 pub struct FnData<'tcx> {
+    pub asyncness: hir::IsAsync,
     pub constness: hir::Constness,
     pub param_names: Lazy<[ast::Name]>,
     pub sig: Lazy<ty::PolyFnSig<'tcx>>,

src/librustc_typeck/check/pat.rs

@@ -676,7 +676,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
         } else {
             // Pattern has wrong number of fields.
-            self.e0023(pat.span, res, &subpats, &variant.fields, expected);
+            self.e0023(pat.span, res, qpath, subpats, &variant.fields, expected);
             on_error();
             return tcx.types.err;
         }
@@ -687,22 +687,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         pat_span: Span,
         res: Res,
+        qpath: &hir::QPath,
         subpats: &'tcx [P<Pat>],
         fields: &[ty::FieldDef],
         expected: Ty<'tcx>
     ) {
         let subpats_ending = pluralise!(subpats.len());
         let fields_ending = pluralise!(fields.len());
-        let missing_parenthesis = match expected.sty {
-            ty::Adt(_, substs) if fields.len() == 1 => {
-                let field_ty = fields[0].ty(self.tcx, substs);
-                match field_ty.sty {
-                    ty::Tuple(_) => field_ty.tuple_fields().count() == subpats.len(),
-                    _ => false,
-                }
-            }
-            _ => false,
-        };
         let res_span = self.tcx.def_span(res.def_id());
         let mut err = struct_span_err!(
             self.tcx.sess,
@@ -723,11 +714,53 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ))
             .span_label(res_span, format!("{} defined here", res.descr()));
 
+        // Identify the case `Some(x, y)` where the expected type is e.g. `Option<(T, U)>`.
+        // More generally, the expected type wants a tuple variant with one field of an
+        // N-arity-tuple, e.g., `V_i((p_0, .., p_N))`. Meanwhile, the user supplied a pattern
+        // with the subpatterns directly in the tuple variant pattern, e.g., `V_i(p_0, .., p_N)`.
+        let missing_parenthesis = match expected.sty {
+            ty::Adt(_, substs) if fields.len() == 1 => {
+                let field_ty = fields[0].ty(self.tcx, substs);
+                match field_ty.sty {
+                    ty::Tuple(_) => field_ty.tuple_fields().count() == subpats.len(),
+                    _ => false,
+                }
+            }
+            _ => false,
+        };
         if missing_parenthesis {
+            let (left, right) = match subpats {
+                // This is the zero case; we aim to get the "hi" part of the `QPath`'s
+                // span as the "lo" and then the "hi" part of the pattern's span as the "hi".
+                // This looks like:
+                //
+                // help: missing parenthesis
+                //   |
+                // L |     let A(()) = A(());
+                //   |          ^  ^
+                [] => {
+                    let qpath_span = match qpath {
+                        hir::QPath::Resolved(_, path) => path.span,
+                        hir::QPath::TypeRelative(_, ps) => ps.ident.span,
+                    };
+                    (qpath_span.shrink_to_hi(), pat_span)
+                },
+                // Easy case. Just take the "lo" of the first sub-pattern and the "hi" of the
+                // last sub-pattern. In the case of `A(x)` the first and last may coincide.
+                // This looks like:
+                //
+                // help: missing parenthesis
+                //   |
+                // L |     let A((x, y)) = A((1, 2));
+                //   |           ^    ^
+                [first, ..] => (first.span.shrink_to_lo(), subpats.last().unwrap().span),
+            };
             err.multipart_suggestion(
                 "missing parenthesis",
-                vec![(subpats[0].span.shrink_to_lo(), "(".to_string()),
-                    (subpats[subpats.len()-1].span.shrink_to_hi(), ")".to_string())],
+                vec![
+                    (left, "(".to_string()),
+                    (right.shrink_to_hi(), ")".to_string()),
+                ],
                 Applicability::MachineApplicable,
             );
         }

src/librustdoc/clean/inline.rs

@@ -217,7 +217,7 @@ fn build_external_function(cx: &DocContext<'_>, did: DefId) -> clean::Function {
     } else {
         hir::Constness::NotConst
     };
-
+    let asyncness =  cx.tcx.asyncness(did);
     let predicates = cx.tcx.predicates_of(did);
     let (generics, decl) = clean::enter_impl_trait(cx, || {
         ((cx.tcx.generics_of(did), &predicates).clean(cx), (did, sig).clean(cx))
@@ -230,7 +230,7 @@ fn build_external_function(cx: &DocContext<'_>, did: DefId) -> clean::Function {
             unsafety: sig.unsafety(),
             abi: sig.abi(),
             constness,
-            asyncness: hir::IsAsync::NotAsync,
+            asyncness,
         },
         all_types,
         ret_types,

src/librustdoc/clean/mod.rs

@@ -2403,6 +2403,7 @@ impl Clean<Item> for ty::AssocItem {
                     } else {
                         hir::Constness::NotConst
                     };
+                    let asyncness = cx.tcx.asyncness(self.def_id);
                     let defaultness = match self.container {
                         ty::ImplContainer(_) => Some(self.defaultness),
                         ty::TraitContainer(_) => None,
@@ -2414,7 +2415,7 @@ impl Clean<Item> for ty::AssocItem {
                             unsafety: sig.unsafety(),
                             abi: sig.abi(),
                             constness,
-                            asyncness: hir::IsAsync::NotAsync,
+                            asyncness,
                         },
                         defaultness,
                         all_types,

src/stage0.txt

@@ -12,7 +12,7 @@
 # source tarball for a stable release you'll likely see `1.x.0` for rustc and
 # `0.x.0` for Cargo where they were released on `date`.
 
-date: 2019-09-24
+date: 2019-09-26
 rustc: 1.38.0
 cargo: 0.39.0
 
@@ -34,4 +34,4 @@ cargo: 0.39.0
 # looking at a beta source tarball and it's uncommented we'll shortly comment it
 # out.
 
-dev: 1
+#dev: 1

src/test/rustdoc/inline_cross/auxiliary/impl_trait_aux.rs

@@ -1,3 +1,5 @@
+// edition:2018
+
 use std::ops::Deref;
 
 pub fn func<'a>(_x: impl Clone + Into<Vec<u8>> + 'a) {}
@@ -11,8 +13,16 @@ pub fn func3(_x: impl Iterator<Item = impl Iterator<Item = u8>> + Clone) {}
 
 pub fn func4<T: Iterator<Item = impl Clone>>(_x: T) {}
 
+pub async fn async_fn() {}
+
 pub struct Foo;
 
 impl Foo {
     pub fn method<'a>(_x: impl Clone + Into<Vec<u8>> + 'a) {}
 }
+
+pub struct Bar;
+
+impl Bar {
+    pub async fn async_foo(&self) {}
+}

src/test/rustdoc/inline_cross/impl_trait.rs

@@ -1,4 +1,5 @@
 // aux-build:impl_trait_aux.rs
+// edition:2018
 
 extern crate impl_trait_aux;
 
@@ -20,13 +21,20 @@ pub use impl_trait_aux::func2;
 // @!has - '//pre[@class="rust fn"]' 'where'
 pub use impl_trait_aux::func3;
 
-
 // @has impl_trait/fn.func4.html
 // @has - '//pre[@class="rust fn"]' "func4<T>("
 // @has - '//pre[@class="rust fn"]' "T: Iterator<Item = impl Clone>,"
 pub use impl_trait_aux::func4;
 
+// @has impl_trait/fn.async_fn.html
+// @has - '//pre[@class="rust fn"]' "pub async fn async_fn()"
+pub use impl_trait_aux::async_fn;
+
 // @has impl_trait/struct.Foo.html
 // @has - '//code[@id="method.v"]' "pub fn method<'a>(_x: impl Clone + Into<Vec<u8>> + 'a)"
 // @!has - '//code[@id="method.v"]' 'where'
 pub use impl_trait_aux::Foo;
+
+// @has impl_trait/struct.Bar.html
+// @has - '//*[@id="method.async_foo"]' "pub async fn async_foo("
+pub use impl_trait_aux::Bar;

src/test/ui/error-codes/E0023.rs

@@ -2,15 +2,16 @@ enum Fruit {
     Apple(String, String),
     Pear(u32),
     Orange((String, String)),
+    Banana(()),
 }
 
-
 fn main() {
     let x = Fruit::Apple(String::new(), String::new());
     match x {
         Fruit::Apple(a) => {}, //~ ERROR E0023
         Fruit::Apple(a, b, c) => {}, //~ ERROR E0023
         Fruit::Pear(1, 2) => {}, //~ ERROR E0023
         Fruit::Orange(a, b) => {}, //~ ERROR E0023
+        Fruit::Banana() => {}, //~ ERROR E0023
     }
 }

src/test/ui/error-codes/E0023.stderr

@@ -38,6 +38,19 @@ help: missing parenthesis
 LL |         Fruit::Orange((a, b)) => {},
    |                       ^    ^
 
-error: aborting due to 4 previous errors
+error[E0023]: this pattern has 0 fields, but the corresponding tuple variant has 1 field
+  --> $DIR/E0023.rs:15:9
+   |
+LL |     Banana(()),
+   |     ---------- tuple variant defined here
+...
+LL |         Fruit::Banana() => {},
+   |         ^^^^^^^^^^^^^^^ expected 1 field, found 0
+help: missing parenthesis
+   |
+LL |         Fruit::Banana(()) => {},
+   |                      ^  ^
+
+error: aborting due to 5 previous errors
 
 For more information about this error, try `rustc --explain E0023`.