Rollup of 3 pull requests

src/ci/azure-pipelines/auto.yml

@@ -273,7 +273,7 @@ jobs:
         MSYS_BITS: 32
         RUST_CONFIGURE_ARGS: --build=i686-pc-windows-gnu
         SCRIPT: make ci-subset-1
-        MINGW_URL: https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror
+        MINGW_URL: https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc
         MINGW_ARCHIVE: i686-6.3.0-release-posix-dwarf-rt_v5-rev2.7z
         MINGW_DIR: mingw32
         # FIXME(#59637)
@@ -283,14 +283,14 @@ jobs:
         MSYS_BITS: 32
         RUST_CONFIGURE_ARGS: --build=i686-pc-windows-gnu
         SCRIPT: make ci-subset-2
-        MINGW_URL: https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror
+        MINGW_URL: https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc
         MINGW_ARCHIVE: i686-6.3.0-release-posix-dwarf-rt_v5-rev2.7z
         MINGW_DIR: mingw32
       x86_64-mingw-1:
         MSYS_BITS: 64
         SCRIPT: make ci-subset-1
         RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-gnu
-        MINGW_URL: https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror
+        MINGW_URL: https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc
         MINGW_ARCHIVE: x86_64-6.3.0-release-posix-seh-rt_v5-rev2.7z
         MINGW_DIR: mingw64
         # FIXME(#59637)
@@ -300,7 +300,7 @@ jobs:
         MSYS_BITS: 64
         SCRIPT: make ci-subset-2
         RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-gnu
-        MINGW_URL: https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror
+        MINGW_URL: https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc
         MINGW_ARCHIVE: x86_64-6.3.0-release-posix-seh-rt_v5-rev2.7z
         MINGW_DIR: mingw64
 
@@ -327,7 +327,7 @@ jobs:
         MSYS_BITS: 32
         RUST_CONFIGURE_ARGS: --build=i686-pc-windows-gnu --enable-full-tools --enable-profiler
         SCRIPT: python x.py dist
-        MINGW_URL: https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror
+        MINGW_URL: https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc
         MINGW_ARCHIVE: i686-6.3.0-release-posix-dwarf-rt_v5-rev2.7z
         MINGW_DIR: mingw32
         DIST_REQUIRE_ALL_TOOLS: 1
@@ -336,7 +336,7 @@ jobs:
         MSYS_BITS: 64
         SCRIPT: python x.py dist
         RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-gnu --enable-full-tools --enable-profiler
-        MINGW_URL: https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror
+        MINGW_URL: https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc
         MINGW_ARCHIVE: x86_64-6.3.0-release-posix-seh-rt_v5-rev2.7z
         MINGW_DIR: mingw64
         DIST_REQUIRE_ALL_TOOLS: 1

src/ci/azure-pipelines/steps/install-clang.yml

@@ -36,7 +36,7 @@ steps:
     set -e
     mkdir -p citools
     cd citools
-    curl -f https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/LLVM-7.0.0-win64.tar.gz | tar xzf -
+    curl -f https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/LLVM-7.0.0-win64.tar.gz | tar xzf -
     echo "##vso[task.setvariable variable=RUST_CONFIGURE_ARGS]$RUST_CONFIGURE_ARGS --set llvm.clang-cl=`pwd`/clang-rust/bin/clang-cl.exe"
   condition: and(succeeded(), eq(variables['Agent.OS'], 'Windows_NT'), eq(variables['MINGW_URL'],''))
   displayName: Install clang (Windows)

src/ci/azure-pipelines/steps/install-sccache.yml

@@ -2,14 +2,14 @@ steps:
 
 - bash: |
     set -e
-    curl -fo /usr/local/bin/sccache https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/2018-04-02-sccache-x86_64-apple-darwin
+    curl -fo /usr/local/bin/sccache https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/2018-04-02-sccache-x86_64-apple-darwin
     chmod +x /usr/local/bin/sccache
   displayName: Install sccache (OSX)
   condition: and(succeeded(), eq(variables['Agent.OS'], 'Darwin'))
 
 - script: |
     md sccache
-    powershell -Command "$ProgressPreference = 'SilentlyContinue'; iwr -outf sccache\sccache.exe https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/2018-04-26-sccache-x86_64-pc-windows-msvc"
+    powershell -Command "$ProgressPreference = 'SilentlyContinue'; iwr -outf sccache\sccache.exe https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/2018-04-26-sccache-x86_64-pc-windows-msvc"
     echo ##vso[task.prependpath]%CD%\sccache
   displayName: Install sccache (Windows)
   condition: and(succeeded(), eq(variables['Agent.OS'], 'Windows_NT'))

src/ci/azure-pipelines/steps/install-windows-build-deps.yml

@@ -4,7 +4,7 @@ steps:
 # https://github.com/wixtoolset/wix3 originally
 - bash: |
     set -e
-    curl -O https://rust-lang-ci2.s3-us-west-1.amazonaws.com/rust-ci-mirror/wix311-binaries.zip
+    curl -O https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/wix311-binaries.zip
     echo "##vso[task.setvariable variable=WIX]`pwd`/wix"
     mkdir -p wix/bin
     cd wix/bin
@@ -18,7 +18,7 @@ steps:
 # one is MSI installers and one is EXE, but they're not used so frequently at
 # this point anyway so perhaps it's a wash!
 - script: |
-    powershell -Command "$ProgressPreference = 'SilentlyContinue'; iwr -outf is-install.exe https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/2017-08-22-is.exe"
+    powershell -Command "$ProgressPreference = 'SilentlyContinue'; iwr -outf is-install.exe https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/2017-08-22-is.exe"
     is-install.exe /VERYSILENT /SUPPRESSMSGBOXES /NORESTART /SP-
     echo ##vso[task.prependpath]C:\Program Files (x86)\Inno Setup 5
   displayName: Install InnoSetup
@@ -109,7 +109,7 @@ steps:
 # Note that this is originally from the github releases patch of Ninja
 - script: |
     md ninja
-    powershell -Command "$ProgressPreference = 'SilentlyContinue'; iwr -outf 2017-03-15-ninja-win.zip https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/2017-03-15-ninja-win.zip"
+    powershell -Command "$ProgressPreference = 'SilentlyContinue'; iwr -outf 2017-03-15-ninja-win.zip https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/2017-03-15-ninja-win.zip"
     7z x -oninja 2017-03-15-ninja-win.zip
     del 2017-03-15-ninja-win.zip
     set RUST_CONFIGURE_ARGS=%RUST_CONFIGURE_ARGS% --enable-ninja

src/ci/docker/armhf-gnu/Dockerfile

@@ -72,7 +72,7 @@ RUN arm-linux-gnueabihf-gcc addentropy.c -o rootfs/addentropy -static
 
 # TODO: What is this?!
 # Source of the file: https://github.com/vfdev-5/qemu-rpi2-vexpress/raw/master/vexpress-v2p-ca15-tc1.dtb
-RUN curl -O https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/vexpress-v2p-ca15-tc1.dtb
+RUN curl -O https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/vexpress-v2p-ca15-tc1.dtb
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh

src/ci/docker/dist-various-1/install-mips-musl.sh

@@ -5,7 +5,7 @@ mkdir /usr/local/mips-linux-musl
 # originally from
 # https://downloads.openwrt.org/snapshots/trunk/ar71xx/generic/
 # OpenWrt-Toolchain-ar71xx-generic_gcc-5.3.0_musl-1.1.16.Linux-x86_64.tar.bz2
-URL="https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror"
+URL="https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc"
 FILE="OpenWrt-Toolchain-ar71xx-generic_gcc-5.3.0_musl-1.1.16.Linux-x86_64.tar.bz2"
 curl -L "$URL/$FILE" | tar xjf - -C /usr/local/mips-linux-musl --strip-components=2
 

src/ci/docker/dist-various-2/build-wasi-toolchain.sh

@@ -5,7 +5,7 @@
 set -ex
 
 # Originally from https://releases.llvm.org/8.0.0/clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-14.04.tar.xz
-curl https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/clang%2Bllvm-8.0.0-x86_64-linux-gnu-ubuntu-14.04.tar.xz | \
+curl https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/clang%2Bllvm-8.0.0-x86_64-linux-gnu-ubuntu-14.04.tar.xz | \
   tar xJf -
 export PATH=`pwd`/clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-14.04/bin:$PATH
 

src/ci/docker/dist-x86_64-linux/build-openssl.sh

@@ -4,7 +4,7 @@ set -ex
 source shared.sh
 
 VERSION=1.0.2k
-URL=https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/openssl-$VERSION.tar.gz
+URL=https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/openssl-$VERSION.tar.gz
 
 curl $URL | tar xzf -
 

src/ci/docker/dist-x86_64-netbsd/build-netbsd-toolchain.sh

@@ -25,7 +25,7 @@ cd netbsd
 
 mkdir -p /x-tools/x86_64-unknown-netbsd/sysroot
 
-URL=https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror
+URL=https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc
 
 # Originally from ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-$BSD/source/sets/*.tgz
 curl $URL/2018-03-01-netbsd-src.tgz | tar xzf -

src/ci/docker/scripts/android-sdk-manager.py

@@ -23,8 +23,9 @@
 HOST_OS = "linux"
 
 # Mirroring options
-MIRROR_BUCKET = "rust-lang-ci2"
-MIRROR_BASE_DIR = "rust-ci-mirror/android/"
+MIRROR_BUCKET = "rust-lang-ci-mirrors"
+MIRROR_BUCKET_REGION = "us-west-1"
+MIRROR_BASE_DIR = "rustc/android/"
 
 import argparse
 import hashlib
@@ -144,7 +145,8 @@ def cli_install(args):
     lockfile = Lockfile(args.lockfile)
     for package in lockfile.packages.values():
         # Download the file from the mirror into a temp file
-        url = "https://" + MIRROR_BUCKET + ".s3.amazonaws.com/" + MIRROR_BASE_DIR
+        url = "https://" + MIRROR_BUCKET + ".s3-" + MIRROR_BUCKET_REGION + \
+              ".amazonaws.com/" + MIRROR_BASE_DIR
         downloaded = package.download(url)
         # Extract the file in a temporary directory
         extract_dir = tempfile.mkdtemp()

src/ci/docker/scripts/freebsd-toolchain.sh

@@ -59,7 +59,7 @@ done
 
 # Originally downloaded from:
 # https://download.freebsd.org/ftp/releases/${freebsd_arch}/${freebsd_version}-RELEASE/base.txz
-URL=https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/2019-04-04-freebsd-${freebsd_arch}-${freebsd_version}-RELEASE-base.txz
+URL=https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/2019-04-04-freebsd-${freebsd_arch}-${freebsd_version}-RELEASE-base.txz
 curl "$URL" | tar xJf - -C "$sysroot" --wildcards "${files_to_extract[@]}"
 
 # Fix up absolute symlinks from the system image.  This can be removed

src/ci/docker/scripts/sccache.sh

@@ -1,6 +1,6 @@
 set -ex
 
 curl -fo /usr/local/bin/sccache \
-  https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/2018-04-02-sccache-x86_64-unknown-linux-musl
+  https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/2018-04-02-sccache-x86_64-unknown-linux-musl
 
 chmod +x /usr/local/bin/sccache

src/ci/install-awscli.sh

@@ -16,7 +16,7 @@
 set -euo pipefail
 IFS=$'\n\t'
 
-MIRROR="https://rust-lang-ci2.s3.amazonaws.com/rust-ci-mirror/2019-07-27-awscli.tar"
+MIRROR="https://rust-lang-ci-mirrors.s3-us-west-1.amazonaws.com/rustc/2019-07-27-awscli.tar"
 DEPS_DIR="/tmp/awscli-deps"
 
 pip="pip"

src/librustc_typeck/check/mod.rs

@@ -1325,12 +1325,94 @@ fn check_union(tcx: TyCtxt<'_>, id: hir::HirId, span: Span) {
     check_packed(tcx, span, def_id);
 }
 
+/// Checks that an opaque type does not contain cycles and does not use `Self` or `T::Foo`
+/// projections that would result in "inheriting lifetimes".
 fn check_opaque<'tcx>(
     tcx: TyCtxt<'tcx>,
     def_id: DefId,
     substs: SubstsRef<'tcx>,
     span: Span,
-    origin: &hir::OpaqueTyOrigin
+    origin: &hir::OpaqueTyOrigin,
+) {
+    check_opaque_for_inheriting_lifetimes(tcx, def_id, span);
+    check_opaque_for_cycles(tcx, def_id, substs, span, origin);
+}
+
+/// Checks that an opaque type does not use `Self` or `T::Foo` projections that would result
+/// in "inheriting lifetimes".
+fn check_opaque_for_inheriting_lifetimes(
+    tcx: TyCtxt<'tcx>,
+    def_id: DefId,
+    span: Span,
+) {
+    let item = tcx.hir().expect_item(
+        tcx.hir().as_local_hir_id(def_id).expect("opaque type is not local"));
+    debug!("check_opaque_for_inheriting_lifetimes: def_id={:?} span={:?} item={:?}",
+           def_id, span, item);
+
+    #[derive(Debug)]
+    struct ProhibitOpaqueVisitor<'tcx> {
+        opaque_identity_ty: Ty<'tcx>,
+        generics: &'tcx ty::Generics,
+    };
+
+    impl<'tcx> ty::fold::TypeVisitor<'tcx> for ProhibitOpaqueVisitor<'tcx> {
+        fn visit_ty(&mut self, t: Ty<'tcx>) -> bool {
+            debug!("check_opaque_for_inheriting_lifetimes: (visit_ty) t={:?}", t);
+            if t == self.opaque_identity_ty { false } else { t.super_visit_with(self) }
+        }
+
+        fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
+            debug!("check_opaque_for_inheriting_lifetimes: (visit_region) r={:?}", r);
+            if let RegionKind::ReEarlyBound(ty::EarlyBoundRegion { index, .. }) = r {
+                return *index < self.generics.parent_count as u32;
+            }
+
+            r.super_visit_with(self)
+        }
+    }
+
+    let prohibit_opaque = match item.node {
+        ItemKind::OpaqueTy(hir::OpaqueTy { origin: hir::OpaqueTyOrigin::AsyncFn, .. }) |
+        ItemKind::OpaqueTy(hir::OpaqueTy { origin: hir::OpaqueTyOrigin::FnReturn, .. }) => {
+            let mut visitor = ProhibitOpaqueVisitor {
+                opaque_identity_ty: tcx.mk_opaque(
+                    def_id, InternalSubsts::identity_for_item(tcx, def_id)),
+                generics: tcx.generics_of(def_id),
+            };
+            debug!("check_opaque_for_inheriting_lifetimes: visitor={:?}", visitor);
+
+            tcx.predicates_of(def_id).predicates.iter().any(
+                |(predicate, _)| predicate.visit_with(&mut visitor))
+        },
+        _ => false,
+    };
+
+    debug!("check_opaque_for_inheriting_lifetimes: prohibit_opaque={:?}", prohibit_opaque);
+    if prohibit_opaque {
+        let is_async = match item.node {
+            ItemKind::OpaqueTy(hir::OpaqueTy { origin, .. }) => match origin {
+                hir::OpaqueTyOrigin::AsyncFn => true,
+                _ => false,
+            },
+            _ => unreachable!(),
+        };
+
+        tcx.sess.span_err(span, &format!(
+            "`{}` return type cannot contain a projection or `Self` that references lifetimes from \
+             a parent scope",
+            if is_async { "async fn" } else { "impl Trait" },
+        ));
+    }
+}
+
+/// Checks that an opaque type does not contain cycles.
+fn check_opaque_for_cycles<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    def_id: DefId,
+    substs: SubstsRef<'tcx>,
+    span: Span,
+    origin: &hir::OpaqueTyOrigin,
 ) {
     if let Err(partially_expanded_type) = tcx.try_expand_impl_trait_type(def_id, substs) {
         if let hir::OpaqueTyOrigin::AsyncFn = origin {

src/test/ui/async-await/issue-61949-self-return-type.rs

@@ -0,0 +1,28 @@
+// ignore-tidy-linelength
+// edition:2018
+#![feature(async_await)]
+
+// This test checks that `Self` is prohibited as a return type. See #61949 for context.
+
+pub struct Foo<'a> {
+    pub bar: &'a i32,
+}
+
+impl<'a> Foo<'a> {
+    pub async fn new(_bar: &'a i32) -> Self {
+    //~^ ERROR `async fn` return type cannot contain a projection or `Self` that references lifetimes from a parent scope
+        Foo {
+            bar: &22
+        }
+    }
+}
+
+async fn foo() {
+    let x = {
+        let bar = 22;
+        Foo::new(&bar).await
+    };
+    drop(x);
+}
+
+fn main() { }

src/test/ui/async-await/issue-61949-self-return-type.stderr

@@ -0,0 +1,8 @@
+error: `async fn` return type cannot contain a projection or `Self` that references lifetimes from a parent scope
+  --> $DIR/issue-61949-self-return-type.rs:12:40
+   |
+LL |     pub async fn new(_bar: &'a i32) -> Self {
+   |                                        ^^^^
+
+error: aborting due to previous error
+

src/test/ui/impl-trait/bound-normalization-fail.rs

@@ -1,4 +1,5 @@
 // compile-fail
+// ignore-tidy-linelength
 // edition:2018
 
 #![feature(async_await)]
@@ -44,7 +45,8 @@ mod lifetimes {
 
     /// Missing bound constraining `Assoc`, `T::Assoc` can't be normalized further.
     fn foo2_fail<'a, T: Trait<'a>>() -> impl FooLike<Output=T::Assoc> {
-        //~^ ERROR: type mismatch
+    //~^ ERROR: type mismatch
+    //~^^ ERROR `impl Trait` return type cannot contain a projection or `Self` that references lifetimes from a parent scope
         Foo(())
     }
 }

src/test/ui/impl-trait/bound-normalization-fail.stderr

@@ -1,13 +1,13 @@
 warning: the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
-  --> $DIR/bound-normalization-fail.rs:5:12
+  --> $DIR/bound-normalization-fail.rs:6:12
    |
 LL | #![feature(impl_trait_in_bindings)]
    |            ^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(incomplete_features)]` on by default
 
 error[E0271]: type mismatch resolving `<Foo<()> as FooLike>::Output == <T as impl_trait::Trait>::Assoc`
-  --> $DIR/bound-normalization-fail.rs:29:32
+  --> $DIR/bound-normalization-fail.rs:30:32
    |
 LL |     fn foo_fail<T: Trait>() -> impl FooLike<Output=T::Assoc> {
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected (), found associated type
@@ -16,8 +16,14 @@ LL |     fn foo_fail<T: Trait>() -> impl FooLike<Output=T::Assoc> {
               found type `<T as impl_trait::Trait>::Assoc`
    = note: the return type of a function must have a statically known size
 
+error: `impl Trait` return type cannot contain a projection or `Self` that references lifetimes from a parent scope
+  --> $DIR/bound-normalization-fail.rs:47:41
+   |
+LL |     fn foo2_fail<'a, T: Trait<'a>>() -> impl FooLike<Output=T::Assoc> {
+   |                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 error[E0271]: type mismatch resolving `<Foo<()> as FooLike>::Output == <T as lifetimes::Trait<'static>>::Assoc`
-  --> $DIR/bound-normalization-fail.rs:46:41
+  --> $DIR/bound-normalization-fail.rs:47:41
    |
 LL |     fn foo2_fail<'a, T: Trait<'a>>() -> impl FooLike<Output=T::Assoc> {
    |                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected (), found associated type
@@ -26,6 +32,6 @@ LL |     fn foo2_fail<'a, T: Trait<'a>>() -> impl FooLike<Output=T::Assoc> {
               found type `<T as lifetimes::Trait<'static>>::Assoc`
    = note: the return type of a function must have a statically known size
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0271`.