New upstream version 1.46.0+dfsg1

RELEASES.md

@@ -1,3 +1,140 @@
+Version 1.46.0 (2020-08-27)
+==========================
+
+Language
+--------
+- [`if`, `match`, and `loop` expressions can now be used in const functions.][72437]
+- [Additionally you are now also able to coerce and cast to slices (`&[T]`) in
+  const functions.][73862]
+- [The `#[track_caller]` attribute can now be added to functions to use the
+  function's caller's location information for panic messages.][72445]
+- [Recursively indexing into tuples no longer needs parentheses.][71322] E.g.
+  `x.0.0` over `(x.0).0`.
+- [`mem::transmute` can now be used in static and constants.][72920] **Note**
+  You currently can't use `mem::transmute` in constant functions.
+
+Compiler
+--------
+- [You can now use the `cdylib` target on Apple iOS and tvOS platforms.][73516]
+- [Enabled static "Position Independent Executables" by default
+  for `x86_64-unknown-linux-musl`.][70740]
+
+Libraries
+---------
+- [`mem::forget` is now a `const fn`.][73887]
+- [`String` now implements `From<char>`.][73466]
+- [The `leading_ones`, and `trailing_ones` methods have been stabilised for all
+  integer types.][73032]
+- [`vec::IntoIter<T>` now implements `AsRef<[T]>`.][72583]
+- [All non-zero integer types (`NonZeroU8`) now implement `TryFrom` for their
+  zero-able equivalent (e.g. `TryFrom<u8>`).][72717]
+- [`&[T]` and `&mut [T]` now implement `PartialEq<Vec<T>>`.][71660]
+- [`(String, u16)` now implements `ToSocketAddrs`.][73007]
+- [`vec::Drain<'_, T>` now implements `AsRef<[T]>`.][72584]
+
+Stabilized APIs
+---------------
+- [`Option::zip`]
+- [`vec::Drain::as_slice`]
+
+Cargo
+-----
+Added a number of new environment variables that are now available when
+compiling your crate.
+
+- [`CARGO_BIN_NAME` and `CARGO_CRATE_NAME`][cargo/8270] Providing the name of
+  the specific binary being compiled and the name of the crate.
+- [`CARGO_PKG_LICENSE`][cargo/8325] The license from the manifest of the package.
+- [`CARGO_PKG_LICENSE_FILE`][cargo/8387] The path to the license file.
+
+Compatibility Notes
+-------------------
+- [The target configuration option `abi_blacklist` has been renamed
+  to `unsupported_abis`.][74150] The old name will still continue to work.
+- [Rustc will now warn if you have a C-like enum that implements `Drop`.][72331]
+  This was previously accepted but will become a hard error in a future release.
+- [Rustc will fail to compile if you have a struct with
+  `#[repr(i128)]` or `#[repr(u128)]`.][74109] This representation is currently only
+  allowed on `enum`s.
+- [Tokens passed to `macro_rules!` are now always captured.][73293] This helps
+  ensure that spans have the correct information, and may cause breakage if you
+  were relying on receiving spans with dummy information.
+- [The InnoSetup installer for Windows is no longer available.][72569] This was
+  a legacy installer that was replaced by a MSI installer a few years ago but
+  was still being built.
+- [`{f32, f64}::asinh` now returns the correct values for negative numbers.][72486]
+- [Rustc will no longer accept overlapping trait implementations that only
+  differ in how the lifetime was bound.][72493]
+- [Rustc now correctly relates the lifetime of an existential associated
+  type.][71896] This fixes some edge cases where `rustc` would erroneously allow
+  you to pass a shorter lifetime than expected.
+- [Rustc now dynamically links to `libz` (also called `zlib`) on Linux.][74420]
+  The library will need to be installed for `rustc` to work, even though we
+  expect it to be already available on most systems.
+- [Tests annotated with `#[should_panic]` are broken on ARMv7 while running
+  under QEMU.][74820]
+- [Pretty printing of some tokens in procedural macros changed.][75453] The
+  exact output returned by rustc's pretty printing is an unstable
+  implementation detail: we recommend any macro relying on it to switch to a
+  more robust parsing system.
+
+[75453]: https://github.com/rust-lang/rust/issues/75453/
+[74820]: https://github.com/rust-lang/rust/issues/74820/
+[74420]: https://github.com/rust-lang/rust/issues/74420/
+[74109]: https://github.com/rust-lang/rust/pull/74109/
+[74150]: https://github.com/rust-lang/rust/pull/74150/
+[73862]: https://github.com/rust-lang/rust/pull/73862/
+[73887]: https://github.com/rust-lang/rust/pull/73887/
+[73466]: https://github.com/rust-lang/rust/pull/73466/
+[73516]: https://github.com/rust-lang/rust/pull/73516/
+[73293]: https://github.com/rust-lang/rust/pull/73293/
+[73007]: https://github.com/rust-lang/rust/pull/73007/
+[73032]: https://github.com/rust-lang/rust/pull/73032/
+[72920]: https://github.com/rust-lang/rust/pull/72920/
+[72569]: https://github.com/rust-lang/rust/pull/72569/
+[72583]: https://github.com/rust-lang/rust/pull/72583/
+[72584]: https://github.com/rust-lang/rust/pull/72584/
+[72717]: https://github.com/rust-lang/rust/pull/72717/
+[72437]: https://github.com/rust-lang/rust/pull/72437/
+[72445]: https://github.com/rust-lang/rust/pull/72445/
+[72486]: https://github.com/rust-lang/rust/pull/72486/
+[72493]: https://github.com/rust-lang/rust/pull/72493/
+[72331]: https://github.com/rust-lang/rust/pull/72331/
+[71896]: https://github.com/rust-lang/rust/pull/71896/
+[71660]: https://github.com/rust-lang/rust/pull/71660/
+[71322]: https://github.com/rust-lang/rust/pull/71322/
+[70740]: https://github.com/rust-lang/rust/pull/70740/
+[cargo/8270]: https://github.com/rust-lang/cargo/pull/8270/
+[cargo/8325]: https://github.com/rust-lang/cargo/pull/8325/
+[cargo/8387]: https://github.com/rust-lang/cargo/pull/8387/
+[`Option::zip`]: https://doc.rust-lang.org/stable/std/option/enum.Option.html#method.zip
+[`vec::Drain::as_slice`]: https://doc.rust-lang.org/stable/std/vec/struct.Drain.html#method.as_slice
+
+
+Version 1.45.2 (2020-08-03)
+==========================
+
+* [Fix bindings in tuple struct patterns][74954]
+* [Fix track_caller integration with trait objects][74784]
+
+[74954]: https://github.com/rust-lang/rust/issues/74954
+[74784]: https://github.com/rust-lang/rust/issues/74784
+
+
+Version 1.45.1 (2020-07-30)
+==========================
+
+* [Fix const propagation with references.][73613]
+* [rustfmt accepts rustfmt_skip in cfg_attr again.][73078]
+* [Avoid spurious implicit region bound.][74509]
+* [Install clippy on x.py install][74457]
+
+[73613]: https://github.com/rust-lang/rust/pull/73613
+[73078]: https://github.com/rust-lang/rust/issues/73078
+[74509]: https://github.com/rust-lang/rust/pull/74509
+[74457]: https://github.com/rust-lang/rust/pull/74457
+
+
 Version 1.45.0 (2020-07-16)
 ==========================
 
@@ -47,7 +184,7 @@ Libraries
   // Prints "abcdefghijklmnopqrstuvwxyz"
   ```
 - [`OsString` now implements `FromStr`.][71662]
-- [The `saturating_neg` method as been added to all signed integer primitive
+- [The `saturating_neg` method has been added to all signed integer primitive
   types, and the `saturating_abs` method has been added for all integer
   primitive types.][71886]
 - [`Arc<T>`, `Rc<T>` now implement  `From<Cow<'_, T>>`, and `Box` now
@@ -82,6 +219,9 @@ Stabilized APIs
 Cargo
 -----
 
+- [Cargo uses the `embed-bitcode` flag to optimize disk usage and build
+  time.][cargo/8066]
+
 Misc
 ----
 - [Rustdoc now supports strikethrough text in Markdown.][71928] E.g.
@@ -97,12 +237,18 @@ Compatibility Notes
 - [Rustdoc's CLI's extra error exit codes have been removed.][71900] These were
   previously undocumented and not intended for public use. Rustdoc still provides
   a non-zero exit code on errors.
+- [Rustc's `lto` flag is incompatible with the new `embed-bitcode=no`.][71848]
+  This may cause issues if LTO is enabled through `RUSTFLAGS` or `cargo rustc`
+  flags while cargo is adding `embed-bitcode` itself. The recommended way to
+  control LTO is with Cargo profiles, either in `Cargo.toml` or `.cargo/config`,
+  or by setting `CARGO_PROFILE_<name>_LTO` in the environment.
 
 Internals Only
 --------------
 - [Make clippy a git subtree instead of a git submodule][70655]
 - [Unify the undo log of all snapshot types][69464]
 
+[71848]: https://github.com/rust-lang/rust/issues/71848/
 [73420]: https://github.com/rust-lang/rust/issues/73420/
 [72324]: https://github.com/rust-lang/rust/pull/72324/
 [71843]: https://github.com/rust-lang/rust/pull/71843/
@@ -129,6 +275,7 @@ Internals Only
 [69813]: https://github.com/rust-lang/rust/pull/69813/
 [69464]: https://github.com/rust-lang/rust/pull/69464/
 [68717]: https://github.com/rust-lang/rust/pull/68717/
+[cargo/8066]: https://github.com/rust-lang/cargo/pull/8066
 [`Arc::as_ptr`]: https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#method.as_ptr
 [`BTreeMap::remove_entry`]: https://doc.rust-lang.org/stable/std/collections/struct.BTreeMap.html#method.remove_entry
 [`Rc::as_ptr`]: https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.as_ptr

git-commit-hash

@@ -1 +1 @@
-6f959902b3103c49ca981fbc01871589c3498489
+04488afe34512aa4c33566eb16d8c912a3ae04f9

src/bootstrap/install.rs

@@ -159,11 +159,6 @@ macro_rules! install {
                 config.extended && config.tools.as_ref()
                     .map_or(true, |t| t.contains($path))
             }
-
-            #[allow(dead_code)]
-            fn should_install(builder: &Builder<'_>) -> bool {
-                builder.config.tools.as_ref().map_or(false, |t| t.contains($path))
-            }
         }
 
         impl Step for $name {
@@ -210,8 +205,7 @@ install!((self, builder, _config),
         install_cargo(builder, self.compiler.stage, self.target);
     };
     Rls, "rls", Self::should_build(_config), only_hosts: true, {
-        if builder.ensure(dist::Rls { compiler: self.compiler, target: self.target }).is_some() ||
+        if builder.ensure(dist::Rls { compiler: self.compiler, target: self.target }).is_some() {
-            Self::should_install(builder) {
             install_rls(builder, self.compiler.stage, self.target);
         } else {
             builder.info(
@@ -221,27 +215,14 @@ install!((self, builder, _config),
     };
     RustAnalyzer, "rust-analyzer", Self::should_build(_config), only_hosts: true, {
         builder.ensure(dist::RustAnalyzer { compiler: self.compiler, target: self.target });
-        if Self::should_install(builder) {
         install_rust_analyzer(builder, self.compiler.stage, self.target);
-        } else {
-            builder.info(
-                &format!("skipping Install rust-analyzer stage{} ({})", self.compiler.stage, self.target),
-            );
-        }
     };
     Clippy, "clippy", Self::should_build(_config), only_hosts: true, {
         builder.ensure(dist::Clippy { compiler: self.compiler, target: self.target });
-        if Self::should_install(builder) {
         install_clippy(builder, self.compiler.stage, self.target);
-        } else {
-            builder.info(
-                &format!("skipping Install clippy stage{} ({})", self.compiler.stage, self.target),
-            );
-        }
     };
     Miri, "miri", Self::should_build(_config), only_hosts: true, {
-        if builder.ensure(dist::Miri { compiler: self.compiler, target: self.target }).is_some() ||
+        if builder.ensure(dist::Miri { compiler: self.compiler, target: self.target }).is_some() {
-            Self::should_install(builder) {
             install_miri(builder, self.compiler.stage, self.target);
         } else {
             builder.info(
@@ -253,7 +234,7 @@ install!((self, builder, _config),
         if builder.ensure(dist::Rustfmt {
             compiler: self.compiler,
             target: self.target
-        }).is_some() || Self::should_install(builder) {
+        }).is_some() {
             install_rustfmt(builder, self.compiler.stage, self.target);
         } else {
             builder.info(

src/ci/azure-pipelines/auto.yml

@@ -10,73 +10,23 @@
 #####################################
 
 #
-# Azure Pipelines "auto" branch build for Rust on Linux, macOS, and Windows.
+# Azure Pipelines "auto" branch build for Rust on macOS
 #
 
 pr: none
 trigger:
   - auto
 
-variables:
-- group: prod-credentials
-
 jobs:
-- job: Linux
-  timeoutInMinutes: 600
-  pool:
-    vmImage: ubuntu-16.04
-  steps:
-  - template: steps/run.yml
-  strategy:
-    matrix:
-      x86_64-gnu-llvm-8:
-        RUST_BACKTRACE: 1
-      dist-x86_64-linux: {}
-      dist-x86_64-linux-alt:
-        IMAGE: dist-x86_64-linux
-      arm-android: {}
-      armhf-gnu: {}
-      dist-various-1: {}
-      dist-various-2: {}
-      dist-aarch64-linux: {}
-      dist-android: {}
-      dist-arm-linux: {}
-      dist-armhf-linux: {}
-      dist-armv7-linux: {}
-      dist-i586-gnu-i586-i686-musl: {}
-      dist-i686-freebsd: {}
-      dist-i686-linux: {}
-      dist-mips-linux: {}
-      dist-mips64-linux: {}
-      dist-mips64el-linux: {}
-      dist-mipsel-linux: {}
-      dist-powerpc-linux: {}
-      dist-powerpc64-linux: {}
-      dist-powerpc64le-linux: {}
-      dist-s390x-linux: {}
-      dist-x86_64-freebsd: {}
-      dist-x86_64-musl: {}
-      dist-x86_64-netbsd: {}
-      i686-gnu: {}
-      i686-gnu-nopt: {}
-      test-various: {}
-      wasm32: {}
-      x86_64-gnu: {}
-      x86_64-gnu-full-bootstrap: {}
-      x86_64-gnu-aux: {}
-      x86_64-gnu-tools:
-        DEPLOY_TOOLSTATES_JSON: toolstates-linux.json
-      x86_64-gnu-debug: {}
-      x86_64-gnu-nopt: {}
-      x86_64-gnu-distcheck: {}
-      mingw-check: {}
-
 - job: macOS
   timeoutInMinutes: 600
   pool:
     vmImage: macos-10.15
   steps:
   - template: steps/run.yml
+  variables:
+    # We're still uploading macOS builds from Azure Pipelines.
+    - group: prod-credentials
   strategy:
     matrix:
       # OSX builders running tests, these run the full test suite.
@@ -110,115 +60,3 @@ jobs:
         MACOSX_DEPLOYMENT_TARGET: 10.7
         NO_LLVM_ASSERTIONS: 1
         NO_DEBUG_ASSERTIONS: 1
-
-
-- job: Windows
-  timeoutInMinutes: 600
-  pool:
-    vmImage: 'vs2017-win2016'
-  steps:
-  - template: steps/run.yml
-  strategy:
-    matrix:
-      # 32/64 bit MSVC tests
-      x86_64-msvc-1:
-        INITIAL_RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-msvc --enable-profiler
-        SCRIPT: make ci-subset-1
-        # FIXME(#59637)
-        NO_DEBUG_ASSERTIONS: 1
-        NO_LLVM_ASSERTIONS: 1
-      x86_64-msvc-2:
-        INITIAL_RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-msvc --enable-profiler
-        SCRIPT: make ci-subset-2
-      i686-msvc-1:
-        INITIAL_RUST_CONFIGURE_ARGS: --build=i686-pc-windows-msvc
-        SCRIPT: make ci-subset-1
-        # FIXME(#59637)
-        NO_DEBUG_ASSERTIONS: 1
-        NO_LLVM_ASSERTIONS: 1
-      i686-msvc-2:
-        INITIAL_RUST_CONFIGURE_ARGS: --build=i686-pc-windows-msvc
-        SCRIPT: make ci-subset-2
-        # FIXME(#59637)
-        NO_DEBUG_ASSERTIONS: 1
-        NO_LLVM_ASSERTIONS: 1
-      x86_64-msvc-cargo:
-        SCRIPT: python x.py test src/tools/cargotest src/tools/cargo
-        INITIAL_RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-msvc --enable-lld
-        VCVARS_BAT: vcvars64.bat
-        # FIXME(#59637)
-        NO_DEBUG_ASSERTIONS: 1
-        NO_LLVM_ASSERTIONS: 1
-      # MSVC tools tests
-      x86_64-msvc-tools:
-        SCRIPT: src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh x.py
-        INITIAL_RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-msvc --save-toolstates=/tmp/toolstate/toolstates.json
-
-      # 32/64-bit MinGW builds.
-      #
-      # We are using MinGW with posix threads since LLVM does not compile with
-      # the win32 threads version due to missing support for C++'s std::thread.
-      #
-      # Instead of relying on the MinGW version installed on appveryor we download
-      # and install one ourselves so we won't be surprised by changes to appveyor's
-      # build image.
-      #
-      # Finally, note that the downloads below are all in the `rust-lang-ci` S3
-      # bucket, but they cleraly didn't originate there! The downloads originally
-      # came from the mingw-w64 SourceForge download site. Unfortunately
-      # SourceForge is notoriously flaky, so we mirror it on our own infrastructure.
-      i686-mingw-1:
-        INITIAL_RUST_CONFIGURE_ARGS: --build=i686-pc-windows-gnu
-        SCRIPT: make ci-mingw-subset-1
-        CUSTOM_MINGW: 1
-        # FIXME(#59637)
-        NO_DEBUG_ASSERTIONS: 1
-        NO_LLVM_ASSERTIONS: 1
-      i686-mingw-2:
-        INITIAL_RUST_CONFIGURE_ARGS: --build=i686-pc-windows-gnu
-        SCRIPT: make ci-mingw-subset-2
-        CUSTOM_MINGW: 1
-      x86_64-mingw-1:
-        SCRIPT: make ci-mingw-subset-1
-        INITIAL_RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-gnu
-        CUSTOM_MINGW: 1
-        # FIXME(#59637)
-        NO_DEBUG_ASSERTIONS: 1
-        NO_LLVM_ASSERTIONS: 1
-      x86_64-mingw-2:
-        SCRIPT: make ci-mingw-subset-2
-        INITIAL_RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-gnu
-        CUSTOM_MINGW: 1
-
-      # 32/64 bit MSVC and GNU deployment
-      dist-x86_64-msvc:
-        INITIAL_RUST_CONFIGURE_ARGS: >-
-          --build=x86_64-pc-windows-msvc
-          --target=x86_64-pc-windows-msvc,aarch64-pc-windows-msvc
-          --enable-full-tools
-          --enable-profiler
-        SCRIPT: python x.py dist
-        DIST_REQUIRE_ALL_TOOLS: 1
-      dist-i686-msvc:
-        INITIAL_RUST_CONFIGURE_ARGS: >-
-          --build=i686-pc-windows-msvc
-          --target=i586-pc-windows-msvc
-          --enable-full-tools
-          --enable-profiler
-        SCRIPT: python x.py dist
-        DIST_REQUIRE_ALL_TOOLS: 1
-      dist-i686-mingw:
-        INITIAL_RUST_CONFIGURE_ARGS: --build=i686-pc-windows-gnu --enable-full-tools --enable-profiler
-        SCRIPT: python x.py dist
-        CUSTOM_MINGW: 1
-        DIST_REQUIRE_ALL_TOOLS: 1
-      dist-x86_64-mingw:
-        SCRIPT: python x.py dist
-        INITIAL_RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-gnu --enable-full-tools --enable-profiler
-        CUSTOM_MINGW: 1
-        DIST_REQUIRE_ALL_TOOLS: 1
-
-      # "alternate" deployment, see .travis.yml for more info
-      dist-x86_64-msvc-alt:
-        INITIAL_RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-msvc --enable-extended --enable-profiler
-        SCRIPT: python x.py dist

src/ci/azure-pipelines/master.yml

@@ -1,33 +0,0 @@
-#####################################
-##    READ BEFORE CHANGING THIS    ##
-#####################################
-
-# We're in the process of evaluating GitHub Actions as a possible replacement
-# for Azure Pipelines, and at the moment the configuration is duplicated
-# between the two CI providers. Be sure to also change the configuration in
-# src/ci/github-actions when changing this file.
-
-#####################################
-
-#
-# Azure Pipelines job to publish toolstate. Only triggers on pushes to master.
-#
-
-pr: none
-trigger:
-  - master
-
-variables:
-- group: prod-credentials
-
-pool:
-  vmImage: ubuntu-16.04
-
-steps:
-- checkout: self
-  fetchDepth: 2
-
-- script: src/ci/publish_toolstate.sh
-  displayName: Publish toolstate
-  env:
-    TOOLSTATE_REPO_ACCESS_TOKEN: $(TOOLSTATE_REPO_ACCESS_TOKEN)

src/ci/azure-pipelines/pr.yml

@@ -1,35 +0,0 @@
-#####################################
-##    READ BEFORE CHANGING THIS    ##
-#####################################
-
-# We're in the process of evaluating GitHub Actions as a possible replacement
-# for Azure Pipelines, and at the moment the configuration is duplicated
-# between the two CI providers. Be sure to also change the configuration in
-# src/ci/github-actions when changing this file.
-
-#####################################
-
-#
-# Azure Pipelines pull request build for Rust
-#
-
-trigger: none
-pr:
-- master
-
-variables:
-- group: public-credentials
-
-jobs:
-- job: Linux
-  timeoutInMinutes: 600
-  pool:
-    vmImage: ubuntu-16.04
-  steps:
-    - template: steps/run.yml
-  strategy:
-    matrix:
-      x86_64-gnu-llvm-8: {}
-      mingw-check: {}
-      x86_64-gnu-tools:
-        CI_ONLY_WHEN_SUBMODULES_CHANGED: 1

src/ci/azure-pipelines/try.yml

@@ -13,70 +13,10 @@ pr: none
 trigger:
 - try
 
-variables:
-- group: prod-credentials
-
 jobs:
-- job: Linux
+- job: Dummy
   timeoutInMinutes: 600
   pool:
     vmImage: ubuntu-16.04
   steps:
-  - template: steps/run.yml
+  - bash: echo "We're running this job since bors is still gating on Azure"
-  strategy:
-    matrix:
-      dist-x86_64-linux: {}
-
-# The macOS and Windows builds here are currently disabled due to them not being
-# overly necessary on `try` builds. We also don't actually have anything that
-# consumes the artifacts currently. Perhaps one day we can re-enable, but for now
-# it helps free up capacity on Azure.
-# - job: macOS
-#   timeoutInMinutes: 600
-#   pool:
-#     vmImage: macos-10.15
-#   steps:
-#   - template: steps/run.yml
-#   strategy:
-#     matrix:
-#       dist-x86_64-apple:
-#         SCRIPT: ./x.py dist
-#         INITIAL_RUST_CONFIGURE_ARGS: --target=aarch64-apple-ios,armv7-apple-ios,armv7s-apple-ios,i386-apple-ios,x86_64-apple-ios --enable-full-tools --enable-sanitizers --enable-profiler --set rust.jemalloc
-#         DEPLOY: 1
-#         RUSTC_RETRY_LINKER_ON_SEGFAULT: 1
-#         MACOSX_DEPLOYMENT_TARGET: 10.7
-#         NO_LLVM_ASSERTIONS: 1
-#         NO_DEBUG_ASSERTIONS: 1
-#         DIST_REQUIRE_ALL_TOOLS: 1
-#
-#       dist-x86_64-apple-alt:
-#         SCRIPT: ./x.py dist
-#         INITIAL_RUST_CONFIGURE_ARGS: --enable-extended --enable-profiler --set rust.jemalloc
-#         DEPLOY_ALT: 1
-#         RUSTC_RETRY_LINKER_ON_SEGFAULT: 1
-#         MACOSX_DEPLOYMENT_TARGET: 10.7
-#         NO_LLVM_ASSERTIONS: 1
-#         NO_DEBUG_ASSERTIONS: 1
-#
-# - job: Windows
-#   timeoutInMinutes: 600
-#   pool:
-#     vmImage: 'vs2017-win2016'
-#   steps:
-#   - template: steps/run.yml
-#   strategy:
-#     matrix:
-#       dist-x86_64-msvc:
-#         INITIAL_RUST_CONFIGURE_ARGS: >
-#           --build=x86_64-pc-windows-msvc
-#           --target=x86_64-pc-windows-msvc,aarch64-pc-windows-msvc
-#           --enable-full-tools
-#           --enable-profiler
-#         SCRIPT: python x.py dist
-#         DIST_REQUIRE_ALL_TOOLS: 1
-#         DEPLOY: 1
-#
-#       dist-x86_64-msvc-alt:
-#         INITIAL_RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-msvc --enable-extended --enable-profiler
-#         SCRIPT: python x.py dist
-#         DEPLOY_ALT: 1

src/ci/docker/host-x86_64/dist-various-2/build-x86_64-fortanix-unknown-sgx-toolchain.sh

@@ -7,7 +7,7 @@ target="x86_64-fortanix-unknown-sgx"
 
 install_prereq() {
     curl https://apt.llvm.org/llvm-snapshot.gpg.key|apt-key add -
-    add-apt-repository -y 'deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic main'
+    add-apt-repository -y 'deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-11 main'
     apt-get update
     apt-get install -y --no-install-recommends \
             build-essential \

src/ci/github-actions/ci.yml

@@ -35,11 +35,26 @@ x--expand-yaml-anchors--remove:
     CI_JOB_NAME: ${{ matrix.name }}
 
   - &public-variables
-    SCCACHE_BUCKET: rust-lang-gha-caches
+    SCCACHE_BUCKET: rust-lang-ci-sccache2
-    TOOLSTATE_REPO: https://github.com/pietroalbini/rust-toolstate
+    TOOLSTATE_REPO: https://github.com/rust-lang-nursery/rust-toolstate
-    CACHE_DOMAIN: ci-caches-gha.rust-lang.org
+    CACHE_DOMAIN: ci-caches.rust-lang.org
 
   - &prod-variables
+    SCCACHE_BUCKET: rust-lang-ci-sccache2
+    DEPLOY_BUCKET: rust-lang-ci2
+    TOOLSTATE_REPO: https://github.com/rust-lang-nursery/rust-toolstate
+    TOOLSTATE_ISSUES_API_URL: https://api.github.com/repos/rust-lang/rust/issues
+    TOOLSTATE_PUBLISH: 1
+    # AWS_SECRET_ACCESS_KEYs are stored in GitHub's secrets storage, named
+    # AWS_SECRET_ACCESS_KEY_<keyid>. Including the key id in the name allows to
+    # rotate them in a single branch while keeping the old key in another
+    # branch, which wouldn't be possible if the key was named with the kind
+    # (caches, artifacts...).
+    CACHES_AWS_ACCESS_KEY_ID: AKIA46X5W6CZI5DHEBFL
+    ARTIFACTS_AWS_ACCESS_KEY_ID: AKIA46X5W6CZN24CBO55
+    CACHE_DOMAIN: ci-caches.rust-lang.org
+
+  - &dummy-variables
     SCCACHE_BUCKET: rust-lang-gha-caches
     DEPLOY_BUCKET: rust-lang-gha
     TOOLSTATE_REPO: https://github.com/pietroalbini/rust-toolstate
@@ -92,6 +107,15 @@ x--expand-yaml-anchors--remove:
         if: success() && !env.SKIP_JOB && github.ref != 'refs/heads/try'
         <<: *step
 
+      # Rust Log Analyzer can't currently detect the PR number of a GitHub
+      # Actions build on its own, so a hint in the log message is needed to
+      # point it in the right direction.
+      - name: configure the PR in which the error message will be posted
+        run: echo "[CI_PR_NUMBER=$num]"
+        env:
+          num: ${{ github.event.number }}
+        if: success() && !env.SKIP_JOBS && github.event_name == 'pull_request'
+
       - name: add extra environment variables
         run: src/ci/scripts/setup-environment.sh
         env:
@@ -550,7 +574,7 @@ jobs:
     <<: *base-ci-job
     name: auto-fallible
     env:
-      <<: [*shared-ci-variables, *prod-variables]
+      <<: [*shared-ci-variables, *dummy-variables]
     if: github.event_name == 'push' && github.ref == 'refs/heads/auto' && github.repository == 'rust-lang-ci/rust'
     strategy:
       matrix:

src/ci/run.sh

@@ -51,7 +51,7 @@ fi
 #
 # FIXME: need a scheme for changing this `nightly` value to `beta` and `stable`
 #        either automatically or manually.
-export RUST_RELEASE_CHANNEL=beta
+export RUST_RELEASE_CHANNEL=stable
 
 # Always set the release channel for bootstrap; this is normally not important (i.e., only dist
 # builds would seem to matter) but in practice bootstrap wants to know whether we're targeting

src/librustc_codegen_ssa/back/link.rs

@@ -1598,7 +1598,9 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>(
     }
 
     // NO-OPT-OUT, OBJECT-FILES-NO, AUDIT-ORDER
+    if sess.target.target.options.eh_frame_header {
         cmd.add_eh_frame_header();
+    }
 
     // NO-OPT-OUT, OBJECT-FILES-NO
     if crt_objects_fallback {

src/librustc_codegen_ssa/back/linker.rs

@@ -619,14 +619,8 @@ impl<'a> Linker for GccLinker<'a> {
     // Some versions of `gcc` add it implicitly, some (e.g. `musl-gcc`) don't,
     // so we just always add it.
     fn add_eh_frame_header(&mut self) {
-        if !self.sess.target.target.options.is_like_osx
-            && !self.sess.target.target.options.is_like_windows
-            && !self.sess.target.target.options.is_like_solaris
-            && self.sess.target.target.target_os != "uefi"
-        {
         self.linker_arg("--eh-frame-hdr");
     }
-    }
 }
 
 pub struct MsvcLinker<'a> {

src/librustc_lint/builtin.rs

@@ -2051,7 +2051,7 @@ impl<'tcx> LateLintPass<'tcx> for InvalidValue {
 
 declare_lint! {
     pub CLASHING_EXTERN_DECLARATIONS,
-    Warn,
+    Allow,
     "detects when an extern fn has been declared with the same name but different types"
 }
 

src/librustc_lint/types.rs

@@ -531,25 +531,30 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
         match ty.kind {
             ty::FnPtr(_) => true,
             ty::Ref(..) => true,
-            ty::Adt(field_def, substs) if field_def.repr.transparent() && !field_def.is_union() => {
+            ty::Adt(def, _)
-                for field in field_def.all_fields() {
+                if def.is_box() && matches!(self.mode, ImproperCTypesMode::Definitions) =>
-                    let field_ty = self.cx.tcx.normalize_erasing_regions(
+            {
-                        self.cx.param_env,
+                true
-                        field.ty(self.cx.tcx, substs),
+            }
-                    );
+            ty::Adt(def, substs) if def.repr.transparent() && !def.is_union() => {
-                    if field_ty.is_zst(self.cx.tcx, field.did) {
+                let guaranteed_nonnull_optimization = self
-                        continue;
+                    .cx
+                    .tcx
+                    .get_attrs(def.did)
+                    .iter()
+                    .any(|a| a.check_name(sym::rustc_nonnull_optimization_guaranteed));
+
+                if guaranteed_nonnull_optimization {
+                    return true;
                 }
 
-                    let attrs = self.cx.tcx.get_attrs(field_def.did);
+                for variant in &def.variants {
-                    if attrs
+                    if let Some(field) = variant.transparent_newtype_field(self.cx.tcx) {
-                        .iter()
+                        if self.ty_is_known_nonnull(field.ty(self.cx.tcx, substs)) {
-                        .any(|a| a.check_name(sym::rustc_nonnull_optimization_guaranteed))
-                        || self.ty_is_known_nonnull(field_ty)
-                    {
                             return true;
                         }
                     }
+                }
 
                 false
             }
@@ -558,7 +563,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
     }
 
     /// Check if this enum can be safely exported based on the "nullable pointer optimization".
-    /// Currently restricted to function pointers, references, `core::num::NonZero*`,
+    /// Currently restricted to function pointers, boxes, references, `core::num::NonZero*`,
     /// `core::ptr::NonNull`, and `#[repr(transparent)]` newtypes.
     fn is_repr_nullable_ptr(
         &self,
@@ -692,6 +697,12 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
         }
 
         match ty.kind {
+            ty::Adt(def, _)
+                if def.is_box() && matches!(self.mode, ImproperCTypesMode::Definitions) =>
+            {
+                FfiSafe
+            }
+
             ty::Adt(def, substs) => {
                 if def.is_phantom_data() {
                     return FfiPhantom(ty);

src/librustc_middle/ty/instance.rs

@@ -375,7 +375,7 @@ impl<'tcx> Instance<'tcx> {
             debug!(" => associated item with unsizeable self: Self");
             Some(Instance { def: InstanceDef::VtableShim(def_id), substs })
         } else {
-            Instance::resolve(tcx, param_env, def_id, substs).ok().flatten()
+            Instance::resolve_for_fn_ptr(tcx, param_env, def_id, substs)
         }
     }
 

src/librustc_mir/transform/const_prop.rs

@@ -484,7 +484,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         lint: &'static lint::Lint,
         source_info: SourceInfo,
         message: &'static str,
-        panic: AssertKind<ConstInt>,
+        panic: AssertKind<impl std::fmt::Debug>,
     ) -> Option<()> {
         let lint_root = self.lint_root(source_info)?;
         self.tcx.struct_span_lint_hir(lint, lint_root, source_info.span, |lint| {
@@ -1004,11 +1004,27 @@ impl<'mir, 'tcx> MutVisitor<'tcx> for ConstPropagator<'mir, 'tcx> {
                     let expected = ScalarMaybeUninit::from(Scalar::from_bool(*expected));
                     let value_const = self.ecx.read_scalar(value).unwrap();
                     if expected != value_const {
+                        enum DbgVal<T> {
+                            Val(T),
+                            Underscore,
+                        }
+                        impl<T: std::fmt::Debug> std::fmt::Debug for DbgVal<T> {
+                            fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                                match self {
+                                    Self::Val(val) => val.fmt(fmt),
+                                    Self::Underscore => fmt.write_str("_"),
+                                }
+                            }
+                        }
                         let mut eval_to_int = |op| {
-                            let op = self
+                            // This can be `None` if the lhs wasn't const propagated and we just
-                                .eval_operand(op, source_info)
+                            // triggered the assert on the value of the rhs.
-                                .expect("if we got here, it must be const");
+                            match self.eval_operand(op, source_info) {
-                            self.ecx.read_immediate(op).unwrap().to_const_int()
+                                Some(op) => {
+                                    DbgVal::Val(self.ecx.read_immediate(op).unwrap().to_const_int())
+                                }
+                                None => DbgVal::Underscore,
+                            }
                         };
                         let msg = match msg {
                             AssertKind::DivisionByZero(op) => {

src/librustc_mir/transform/qualify_min_const_fn.rs

@@ -193,7 +193,15 @@ fn check_rvalue(
             _,
         ) => Err((span, "function pointer casts are not allowed in const fn".into())),
         Rvalue::Cast(CastKind::Pointer(PointerCast::Unsize), op, cast_ty) => {
-            let pointee_ty = cast_ty.builtin_deref(true).unwrap().ty;
+            let pointee_ty = if let Some(deref_ty) = cast_ty.builtin_deref(true) {
+                deref_ty.ty
+            } else {
+                // We cannot allow this for now.
+                return Err((
+                    span,
+                    "unsizing casts are only allowed for references right now".into(),
+                ));
+            };
             let unsized_ty = tcx.struct_tail_erasing_lifetimes(pointee_ty, tcx.param_env(def_id));
             if let ty::Slice(_) | ty::Str = unsized_ty.kind {
                 check_operand(tcx, op, span, def_id, body)?;

src/librustc_target/spec/aarch64_apple_darwin.rs

@@ -0,0 +1,30 @@
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
+
+pub fn target() -> TargetResult {
+    let mut base = super::apple_base::opts();
+    base.cpu = "apple-a12".to_string();
+    base.max_atomic_width = Some(128);
+    base.pre_link_args.insert(LinkerFlavor::Gcc, vec!["-arch".to_string(), "arm64".to_string()]);
+
+    base.link_env_remove.extend(super::apple_base::macos_link_env_remove());
+
+    // Clang automatically chooses a more specific target based on
+    // MACOSX_DEPLOYMENT_TARGET.  To enable cross-language LTO to work
+    // correctly, we do too.
+    let arch = "aarch64";
+    let llvm_target = super::apple_base::macos_llvm_target(&arch);
+
+    Ok(Target {
+        llvm_target,
+        target_endian: "little".to_string(),
+        target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
+        data_layout: "e-m:o-i64:64-i128:128-n32:64-S128".to_string(),
+        arch: arch.to_string(),
+        target_os: "macos".to_string(),
+        target_env: String::new(),
+        target_vendor: "apple".to_string(),
+        linker_flavor: LinkerFlavor::Gcc,
+        options: TargetOptions { target_mcount: "\u{1}mcount".to_string(), ..base },
+    })
+}

src/librustc_target/spec/apple_base.rs

@@ -31,6 +31,7 @@ pub fn opts() -> TargetOptions {
         has_elf_tls: version >= (10, 7),
         abi_return_struct_as_int: true,
         emit_debug_gdb_scripts: false,
+        eh_frame_header: false,
 
         // This environment variable is pretty magical but is intended for
         // producing deterministic builds. This was first discovered to be used

src/librustc_target/spec/freestanding_base.rs

@@ -25,6 +25,7 @@ pub fn opts() -> TargetOptions {
         has_rpath: false,
         pre_link_args: args,
         position_independent_executables: false,
+        eh_frame_header: false,
         ..Default::default()
     }
 }

src/librustc_target/spec/illumos_base.rs

@@ -23,6 +23,7 @@ pub fn opts() -> TargetOptions {
         is_like_solaris: true,
         limit_rdylib_exports: false, // Linker doesn't support this
         eliminate_frame_pointer: false,
+        eh_frame_header: false,
         late_link_args,
 
         // While we support ELF TLS, rust requires a way to register

src/librustc_target/spec/mod.rs

@@ -574,6 +574,7 @@ supported_targets! {
     ("i686-unknown-haiku", i686_unknown_haiku),
     ("x86_64-unknown-haiku", x86_64_unknown_haiku),
 
+    ("aarch64-apple-darwin", aarch64_apple_darwin),
     ("x86_64-apple-darwin", x86_64_apple_darwin),
     ("i686-apple-darwin", i686_apple_darwin),
 
@@ -989,6 +990,11 @@ pub struct TargetOptions {
     /// Whether to use legacy .ctors initialization hooks rather than .init_array. Defaults
     /// to false (uses .init_array).
     pub use_ctors_section: bool,
+
+    /// Whether the linker is instructed to add a `GNU_EH_FRAME` ELF header
+    /// used to locate unwinding information is passed
+    /// (only has effect if the linker is `ld`-like).
+    pub eh_frame_header: bool,
 }
 
 impl Default for TargetOptions {
@@ -1081,6 +1087,7 @@ impl Default for TargetOptions {
             relax_elf_relocations: false,
             llvm_args: vec![],
             use_ctors_section: false,
+            eh_frame_header: true,
         }
     }
 }
@@ -1474,6 +1481,7 @@ impl Target {
         key!(relax_elf_relocations, bool);
         key!(llvm_args, list);
         key!(use_ctors_section, bool);
+        key!(eh_frame_header, bool);
 
         // NB: The old name is deprecated, but support for it is retained for
         // compatibility.
@@ -1712,6 +1720,7 @@ impl ToJson for Target {
         target_option_val!(relax_elf_relocations);
         target_option_val!(llvm_args);
         target_option_val!(use_ctors_section);
+        target_option_val!(eh_frame_header);
 
         if default.unsupported_abis != self.options.unsupported_abis {
             d.insert(

src/librustc_target/spec/msp430_none_elf.rs

@@ -56,6 +56,8 @@ pub fn target() -> TargetResult {
             // See the thumb_base.rs file for an explanation of this value
             emit_debug_gdb_scripts: false,
 
+            eh_frame_header: false,
+
             ..Default::default()
         },
     })

src/librustc_target/spec/riscv32i_unknown_none_elf.rs

@@ -25,6 +25,7 @@ pub fn target() -> TargetResult {
             relocation_model: RelocModel::Static,
             emit_debug_gdb_scripts: false,
             unsupported_abis: super::riscv_base::unsupported_abis(),
+            eh_frame_header: false,
             ..Default::default()
         },
     })

src/librustc_target/spec/riscv32imac_unknown_none_elf.rs

@@ -25,6 +25,7 @@ pub fn target() -> TargetResult {
             relocation_model: RelocModel::Static,
             emit_debug_gdb_scripts: false,
             unsupported_abis: super::riscv_base::unsupported_abis(),
+            eh_frame_header: false,
             ..Default::default()
         },
     })

src/librustc_target/spec/riscv32imc_unknown_none_elf.rs

@@ -25,6 +25,7 @@ pub fn target() -> TargetResult {
             relocation_model: RelocModel::Static,
             emit_debug_gdb_scripts: false,
             unsupported_abis: super::riscv_base::unsupported_abis(),
+            eh_frame_header: false,
             ..Default::default()
         },
     })

src/librustc_target/spec/riscv64gc_unknown_none_elf.rs

@@ -26,6 +26,7 @@ pub fn target() -> TargetResult {
             code_model: Some(CodeModel::Medium),
             emit_debug_gdb_scripts: false,
             unsupported_abis: super::riscv_base::unsupported_abis(),
+            eh_frame_header: false,
             ..Default::default()
         },
     })

src/librustc_target/spec/riscv64imac_unknown_none_elf.rs

@@ -26,6 +26,7 @@ pub fn target() -> TargetResult {
             code_model: Some(CodeModel::Medium),
             emit_debug_gdb_scripts: false,
             unsupported_abis: super::riscv_base::unsupported_abis(),
+            eh_frame_header: false,
             ..Default::default()
         },
     })

src/librustc_target/spec/solaris_base.rs

@@ -8,6 +8,7 @@ pub fn opts() -> TargetOptions {
         target_family: Some("unix".to_string()),
         is_like_solaris: true,
         limit_rdylib_exports: false, // Linker doesn't support this
+        eh_frame_header: false,
 
         ..Default::default()
     }

src/librustc_target/spec/windows_gnu_base.rs

@@ -91,6 +91,7 @@ pub fn opts() -> TargetOptions {
         abi_return_struct_as_int: true,
         emit_debug_gdb_scripts: false,
         requires_uwtable: true,
+        eh_frame_header: false,
 
         ..Default::default()
     }

src/librustc_target/spec/x86_64_apple_darwin.rs

@@ -5,7 +5,10 @@ pub fn target() -> TargetResult {
     base.cpu = "core2".to_string();
     base.max_atomic_width = Some(128); // core2 support cmpxchg16b
     base.eliminate_frame_pointer = false;
-    base.pre_link_args.insert(LinkerFlavor::Gcc, vec!["-m64".to_string()]);
+    base.pre_link_args.insert(
+        LinkerFlavor::Gcc,
+        vec!["-m64".to_string(), "-arch".to_string(), "x86_64".to_string()],
+    );
     base.link_env_remove.extend(super::apple_base::macos_link_env_remove());
     base.stack_probes = true;
 

src/librustc_trait_selection/traits/auto_trait.rs

@@ -729,7 +729,7 @@ impl AutoTraitFinder<'tcx> {
                     // and turn them into an explicit negative impl for our type.
                     debug!("Projecting and unifying projection predicate {:?}", predicate);
 
-                    match poly_project_and_unify_type(select, &obligation.with(p)) {
+                    match project::poly_project_and_unify_type(select, &obligation.with(p)) {
                         Err(e) => {
                             debug!(
                                 "evaluate_nested_obligations: Unable to unify predicate \
@@ -738,7 +738,11 @@ impl AutoTraitFinder<'tcx> {
                             );
                             return false;
                         }
-                        Ok(Some(v)) => {
+                        Ok(Err(project::InProgress)) => {
+                            debug!("evaluate_nested_obligations: recursive projection predicate");
+                            return false;
+                        }
+                        Ok(Ok(Some(v))) => {
                             // We only care about sub-obligations
                             // when we started out trying to unify
                             // some inference variables. See the comment above
@@ -757,8 +761,8 @@ impl AutoTraitFinder<'tcx> {
                                 }
                             }
                         }
-                        Ok(None) => {
+                        Ok(Ok(None)) => {
-                            // It's ok not to make progress when hvave no inference variables -
+                            // It's ok not to make progress when have no inference variables -
                             // in that case, we were only performing unifcation to check if an
                             // error occurred (which would indicate that it's impossible for our
                             // type to implement the auto trait).

src/librustc_trait_selection/traits/fulfill.rs

@@ -426,14 +426,20 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
 
             ty::PredicateKind::Projection(ref data) => {
                 let project_obligation = obligation.with(*data);
-                match project::poly_project_and_unify_type(self.selcx, &project_obligation) {
-                    Ok(None) => {
                 let tcx = self.selcx.tcx();
-                        pending_obligation.stalled_on =
+                match project::poly_project_and_unify_type(self.selcx, &project_obligation) {
-                            trait_ref_infer_vars(self.selcx, data.to_poly_trait_ref(tcx));
+                    Ok(Ok(Some(os))) => ProcessResult::Changed(mk_pending(os)),
+                    Ok(Ok(None)) => {
+                        pending_obligation.stalled_on = trait_ref_infer_vars(
+                            self.selcx,
+                            project_obligation.predicate.to_poly_trait_ref(tcx),
+                        );
                         ProcessResult::Unchanged
                     }
-                    Ok(Some(os)) => ProcessResult::Changed(mk_pending(os)),
+                    // Let the caller handle the recursion
+                    Ok(Err(project::InProgress)) => ProcessResult::Changed(mk_pending(vec![
+                        pending_obligation.obligation.clone(),
+                    ])),
                     Err(e) => ProcessResult::Error(CodeProjectionError(e)),
                 }
             }

src/librustc_trait_selection/traits/mod.rs

@@ -51,9 +51,7 @@ pub use self::object_safety::is_vtable_safe_method;
 pub use self::object_safety::MethodViolationCode;
 pub use self::object_safety::ObjectSafetyViolation;
 pub use self::on_unimplemented::{OnUnimplementedDirective, OnUnimplementedNote};
-pub use self::project::{
+pub use self::project::{normalize, normalize_projection_type, normalize_to};
-    normalize, normalize_projection_type, normalize_to, poly_project_and_unify_type,
-};
 pub use self::select::{EvaluationCache, SelectionCache, SelectionContext};
 pub use self::select::{EvaluationResult, IntercrateAmbiguityCause, OverflowError};
 pub use self::specialize::specialization_graph::FutureCompatOverlapError;

src/librustc_trait_selection/traits/project.rs

@@ -40,6 +40,8 @@ pub type ProjectionObligation<'tcx> = Obligation<'tcx, ty::ProjectionPredicate<'
 
 pub type ProjectionTyObligation<'tcx> = Obligation<'tcx, ty::ProjectionTy<'tcx>>;
 
+pub(super) struct InProgress;
+
 /// When attempting to resolve `<T as TraitRef>::Name` ...
 #[derive(Debug)]
 pub enum ProjectionTyError<'tcx> {
@@ -142,10 +144,26 @@ impl<'tcx> ProjectionTyCandidateSet<'tcx> {
 ///
 /// If successful, this may result in additional obligations. Also returns
 /// the projection cache key used to track these additional obligations.
-pub fn poly_project_and_unify_type<'cx, 'tcx>(
+///
+/// ## Returns
+///
+/// - `Err(_)`: the projection can be normalized, but is not equal to the
+///   expected type.
+/// - `Ok(Err(InProgress))`: this is called recursively while normalizing
+///   the same projection.
+/// - `Ok(Ok(None))`: The projection cannot be normalized due to ambiguity
+///   (resolving some inference variables in the projection may fix this).
+/// - `Ok(Ok(Some(obligations)))`: The projection bound holds subject to
+///    the given obligations. If the projection cannot be normalized because
+///    the required trait bound doesn't hold this returned with `obligations`
+///    being a predicate that cannot be proven.
+pub(super) fn poly_project_and_unify_type<'cx, 'tcx>(
     selcx: &mut SelectionContext<'cx, 'tcx>,
     obligation: &PolyProjectionObligation<'tcx>,
-) -> Result<Option<Vec<PredicateObligation<'tcx>>>, MismatchedProjectionTypes<'tcx>> {
+) -> Result<
+    Result<Option<Vec<PredicateObligation<'tcx>>>, InProgress>,
+    MismatchedProjectionTypes<'tcx>,
+> {
     debug!("poly_project_and_unify_type(obligation={:?})", obligation);
 
     let infcx = selcx.infcx();
@@ -164,10 +182,15 @@ pub fn poly_project_and_unify_type<'cx, 'tcx>(
 ///     <T as Trait>::U == V
 ///
 /// If successful, this may result in additional obligations.
+///
+/// See [poly_project_and_unify_type] for an explanation of the return value.
 fn project_and_unify_type<'cx, 'tcx>(
     selcx: &mut SelectionContext<'cx, 'tcx>,
     obligation: &ProjectionObligation<'tcx>,
-) -> Result<Option<Vec<PredicateObligation<'tcx>>>, MismatchedProjectionTypes<'tcx>> {
+) -> Result<
+    Result<Option<Vec<PredicateObligation<'tcx>>>, InProgress>,
+    MismatchedProjectionTypes<'tcx>,
+> {
     debug!("project_and_unify_type(obligation={:?})", obligation);
 
     let mut obligations = vec![];
@@ -179,8 +202,9 @@ fn project_and_unify_type<'cx, 'tcx>(
         obligation.recursion_depth,
         &mut obligations,
     ) {
-        Some(n) => n,
+        Ok(Some(n)) => n,
-        None => return Ok(None),
+        Ok(None) => return Ok(Ok(None)),
+        Err(InProgress) => return Ok(Err(InProgress)),
     };
 
     debug!(
@@ -195,7 +219,7 @@ fn project_and_unify_type<'cx, 'tcx>(
     {
         Ok(InferOk { obligations: inferred_obligations, value: () }) => {
             obligations.extend(inferred_obligations);
-            Ok(Some(obligations))
+            Ok(Ok(Some(obligations)))
         }
         Err(err) => {
             debug!("project_and_unify_type: equating types encountered error {:?}", err);
@@ -323,8 +347,7 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> {
 
         let ty = ty.super_fold_with(self);
         match ty.kind {
-            ty::Opaque(def_id, substs) if !substs.has_escaping_bound_vars() => {
+            ty::Opaque(def_id, substs) => {
-                // (*)
                 // Only normalize `impl Trait` after type-checking, usually in codegen.
                 match self.param_env.reveal() {
                     Reveal::UserFacing => ty,
@@ -352,9 +375,7 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> {
             }
 
             ty::Projection(ref data) if !data.has_escaping_bound_vars() => {
-                // (*)
+                // This is kind of hacky -- we need to be able to
-
-                // (*) This is kind of hacky -- we need to be able to
                 // handle normalization within binders because
                 // otherwise we wind up a need to normalize when doing
                 // trait matching (since you can have a trait
@@ -421,6 +442,8 @@ pub fn normalize_projection_type<'a, 'b, 'tcx>(
         depth,
         obligations,
     )
+    .ok()
+    .flatten()
     .unwrap_or_else(move || {
         // if we bottom out in ambiguity, create a type variable
         // and a deferred predicate to resolve this when more type
@@ -457,7 +480,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
     cause: ObligationCause<'tcx>,
     depth: usize,
     obligations: &mut Vec<PredicateObligation<'tcx>>,
-) -> Option<Ty<'tcx>> {
+) -> Result<Option<Ty<'tcx>>, InProgress> {
     let infcx = selcx.infcx();
 
     let projection_ty = infcx.resolve_vars_if_possible(&projection_ty);
@@ -489,7 +512,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
                 "opt_normalize_projection_type: \
                  found cache entry: ambiguous"
             );
-            return None;
+            return Ok(None);
         }
         Err(ProjectionCacheEntry::InProgress) => {
             // If while normalized A::B, we are asked to normalize
@@ -504,24 +527,14 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
             // to normalize `A::B`, we will want to check the
             // where-clauses in scope. So we will try to unify `A::B`
             // with `A::B`, which can trigger a recursive
-            // normalization. In that case, I think we will want this code:
+            // normalization.
-            //
-            // ```
-            // let ty = selcx.tcx().mk_projection(projection_ty.item_def_id,
-            //                                    projection_ty.substs;
-            // return Some(NormalizedTy { value: v, obligations: vec![] });
-            // ```
 
             debug!(
                 "opt_normalize_projection_type: \
                  found cache entry: in-progress"
             );
 
-            // But for now, let's classify this as an overflow:
+            return Err(InProgress);
-            let recursion_limit = selcx.tcx().sess.recursion_limit();
-            let obligation =
-                Obligation::with_depth(cause, recursion_limit.0, param_env, projection_ty);
-            selcx.infcx().report_overflow_error(&obligation, false);
         }
         Err(ProjectionCacheEntry::NormalizedTy(ty)) => {
             // This is the hottest path in this function.
@@ -557,7 +570,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
                 cause,
                 depth,
             ));
-            return Some(ty.value);
+            return Ok(Some(ty.value));
         }
         Err(ProjectionCacheEntry::Error) => {
             debug!(
@@ -566,7 +579,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
             );
             let result = normalize_to_error(selcx, param_env, projection_ty, cause, depth);
             obligations.extend(result.obligations);
-            return Some(result.value);
+            return Ok(Some(result.value));
         }
     }
 
@@ -613,7 +626,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
             let cache_value = prune_cache_value_obligations(infcx, &result);
             infcx.inner.borrow_mut().projection_cache().insert_ty(cache_key, cache_value);
             obligations.extend(result.obligations);
-            Some(result.value)
+            Ok(Some(result.value))
         }
         Ok(ProjectedTy::NoProgress(projected_ty)) => {
             debug!(
@@ -624,7 +637,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
             let result = Normalized { value: projected_ty, obligations: vec![] };
             infcx.inner.borrow_mut().projection_cache().insert_ty(cache_key, result.clone());
             // No need to extend `obligations`.
-            Some(result.value)
+            Ok(Some(result.value))
         }
         Err(ProjectionTyError::TooManyCandidates) => {
             debug!(
@@ -632,7 +645,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
                  too many candidates"
             );
             infcx.inner.borrow_mut().projection_cache().ambiguous(cache_key);
-            None
+            Ok(None)
         }
         Err(ProjectionTyError::TraitSelectionError(_)) => {
             debug!("opt_normalize_projection_type: ERROR");
@@ -644,7 +657,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
             infcx.inner.borrow_mut().projection_cache().error(cache_key);
             let result = normalize_to_error(selcx, param_env, projection_ty, cause, depth);
             obligations.extend(result.obligations);
-            Some(result.value)
+            Ok(Some(result.value))
         }
     }
 }
@@ -1115,11 +1128,11 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
             }
             super::ImplSourceAutoImpl(..) | super::ImplSourceBuiltin(..) => {
                 // These traits have no associated types.
-                span_bug!(
+                selcx.tcx().sess.delay_span_bug(
                     obligation.cause.span,
-                    "Cannot project an associated type from `{:?}`",
+                    &format!("Cannot project an associated type from `{:?}`", impl_source),
-                    impl_source
                 );
+                return Err(());
             }
         };
 

src/librustc_trait_selection/traits/query/normalize.rs

@@ -101,8 +101,7 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
 
         let ty = ty.super_fold_with(self);
         match ty.kind {
-            ty::Opaque(def_id, substs) if !substs.has_escaping_bound_vars() => {
+            ty::Opaque(def_id, substs) => {
-                // (*)
                 // Only normalize `impl Trait` after type-checking, usually in codegen.
                 match self.param_env.reveal() {
                     Reveal::UserFacing => ty,
@@ -140,8 +139,7 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
             }
 
             ty::Projection(ref data) if !data.has_escaping_bound_vars() => {
-                // (*)
+                // This is kind of hacky -- we need to be able to
-                // (*) This is kind of hacky -- we need to be able to
                 // handle normalization within binders because
                 // otherwise we wind up a need to normalize when doing
                 // trait matching (since you can have a trait

src/librustc_trait_selection/traits/select/mod.rs

@@ -458,7 +458,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             &ty::PredicateKind::Projection(data) => {
                 let project_obligation = obligation.with(data);
                 match project::poly_project_and_unify_type(self, &project_obligation) {
-                    Ok(Some(mut subobligations)) => {
+                    Ok(Ok(Some(mut subobligations))) => {
                         self.add_depth(subobligations.iter_mut(), obligation.recursion_depth);
                         let result = self.evaluate_predicates_recursively(
                             previous_stack,
@@ -471,7 +471,13 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                         }
                         result
                     }
-                    Ok(None) => Ok(EvaluatedToAmbig),
+                    Ok(Ok(None)) => Ok(EvaluatedToAmbig),
+                    // EvaluatedToRecur might also be acceptable here, but use
+                    // Unknown for now because it means that we won't dismiss a
+                    // selection candidate solely because it has a projection
+                    // cycle. This is closest to the previous behavior of
+                    // immediately erroring.
+                    Ok(Err(project::InProgress)) => Ok(EvaluatedToUnknown),
                     Err(_) => Ok(EvaluatedToErr),
                 }
             }

src/librustc_typeck/check/cast.rs

@@ -387,6 +387,7 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                             // Check for infer types because cases like `Option<{integer}>` would
                             // panic otherwise.
                             if !expr_ty.has_infer_types()
+                                && !ty.has_infer_types()
                                 && fcx.tcx.type_implements_trait((
                                     from_trait,
                                     ty,

src/librustc_typeck/check/mod.rs

@@ -252,14 +252,6 @@ pub struct Inherited<'a, 'tcx> {
     /// opaque type.
     opaque_types_vars: RefCell<FxHashMap<Ty<'tcx>, Ty<'tcx>>>,
 
-    /// Each type parameter has an implicit region bound that
-    /// indicates it must outlive at least the function body (the user
-    /// may specify stronger requirements). This field indicates the
-    /// region of the callee. If it is `None`, then the parameter
-    /// environment is for an item or something where the "callee" is
-    /// not clear.
-    implicit_region_bound: Option<ty::Region<'tcx>>,
-
     body_id: Option<hir::BodyId>,
 }
 
@@ -678,7 +670,6 @@ impl Inherited<'a, 'tcx> {
             deferred_generator_interiors: RefCell::new(Vec::new()),
             opaque_types: RefCell::new(Default::default()),
             opaque_types_vars: RefCell::new(Default::default()),
-            implicit_region_bound: None,
             body_id,
         }
     }

src/librustc_typeck/check/place_op.rs

@@ -9,6 +9,7 @@ use rustc_middle::ty::{self, Ty};
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;
 use rustc_trait_selection::autoderef::Autoderef;
+use std::slice;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Type-check `*oprnd_expr` with `oprnd_expr` type-checked already.
@@ -245,19 +246,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
 
             match expr.kind {
-                hir::ExprKind::Index(ref base_expr, ref index_expr) => {
+                hir::ExprKind::Index(ref base_expr, ..) => {
-                    // We need to get the final type in case dereferences were needed for the trait
+                    self.convert_place_op_to_mutable(PlaceOp::Index, expr, base_expr);
-                    // to apply (#72002).
-                    let index_expr_ty = self.tables.borrow().expr_ty_adjusted(index_expr);
-                    self.convert_place_op_to_mutable(
-                        PlaceOp::Index,
-                        expr,
-                        base_expr,
-                        &[index_expr_ty],
-                    );
                 }
                 hir::ExprKind::Unary(hir::UnOp::UnDeref, ref base_expr) => {
-                    self.convert_place_op_to_mutable(PlaceOp::Deref, expr, base_expr, &[]);
+                    self.convert_place_op_to_mutable(PlaceOp::Deref, expr, base_expr);
                 }
                 _ => {}
             }
@@ -269,9 +262,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         op: PlaceOp,
         expr: &hir::Expr<'_>,
         base_expr: &hir::Expr<'_>,
-        arg_tys: &[Ty<'tcx>],
     ) {
-        debug!("convert_place_op_to_mutable({:?}, {:?}, {:?}, {:?})", op, expr, base_expr, arg_tys);
+        debug!("convert_place_op_to_mutable({:?}, {:?}, {:?})", op, expr, base_expr);
         if !self.tables.borrow().is_method_call(expr) {
             debug!("convert_place_op_to_mutable - builtin, nothing to do");
             return;
@@ -286,6 +278,25 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .expect("place op takes something that is not a ref")
             .ty;
 
+        let arg_ty = match op {
+            PlaceOp::Deref => None,
+            PlaceOp::Index => {
+                // We would need to recover the `T` used when we resolve `<_ as Index<T>>::index`
+                // in try_index_step. This is the subst at index 1.
+                //
+                // Note: we should *not* use `expr_ty` of index_expr here because autoderef
+                // during coercions can cause type of index_expr to differ from `T` (#72002).
+                // We also could not use `expr_ty_adjusted` of index_expr because reborrowing
+                // during coercions can also cause type of index_expr to differ from `T`,
+                // which can potentially cause regionck failure (#74933).
+                Some(self.tables.borrow().node_substs(expr.hir_id).type_at(1))
+            }
+        };
+        let arg_tys = match arg_ty {
+            None => &[],
+            Some(ref ty) => slice::from_ref(ty),
+        };
+
         let method = self.try_mutable_overloaded_place_op(expr.span, base_ty, arg_tys, op);
         let method = match method {
             Some(ok) => self.register_infer_ok_obligations(ok),

src/librustc_typeck/check/regionck.rs

@@ -308,7 +308,7 @@ impl<'a, 'tcx> RegionCtxt<'a, 'tcx> {
     fn resolve_regions_and_report_errors(&self, mode: RegionckMode) {
         self.infcx.process_registered_region_obligations(
             self.outlives_environment.region_bound_pairs_map(),
-            self.implicit_region_bound,
+            Some(self.tcx.lifetimes.re_root_empty),
             self.param_env,
         );
 

src/librustc_typeck/lib.rs

@@ -100,7 +100,7 @@ use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::util;
 use rustc_session::config::EntryFnType;
-use rustc_span::{Span, DUMMY_SP};
+use rustc_span::{symbol::sym, Span, DUMMY_SP};
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits::error_reporting::InferCtxtExt as _;
 use rustc_trait_selection::traits::{
@@ -194,6 +194,23 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: LocalDefId) {
                         .emit();
                         error = true;
                     }
+
+                    for attr in it.attrs {
+                        if attr.check_name(sym::track_caller) {
+                            tcx.sess
+                                .struct_span_err(
+                                    attr.span,
+                                    "`main` function is not allowed to be `#[track_caller]`",
+                                )
+                                .span_label(
+                                    main_span,
+                                    "`main` function is not allowed to be `#[track_caller]`",
+                                )
+                                .emit();
+                            error = true;
+                        }
+                    }
+
                     if error {
                         return;
                     }
@@ -268,12 +285,29 @@ fn check_start_fn_ty(tcx: TyCtxt<'_>, start_def_id: LocalDefId) {
                             tcx.sess,
                             span,
                             E0752,
-                            "start is not allowed to be `async`"
+                            "`start` is not allowed to be `async`"
                         )
-                        .span_label(span, "start is not allowed to be `async`")
+                        .span_label(span, "`start` is not allowed to be `async`")
                         .emit();
                         error = true;
                     }
+
+                    for attr in it.attrs {
+                        if attr.check_name(sym::track_caller) {
+                            tcx.sess
+                                .struct_span_err(
+                                    attr.span,
+                                    "`start` is not allowed to be `#[track_caller]`",
+                                )
+                                .span_label(
+                                    start_span,
+                                    "`start` is not allowed to be `#[track_caller]`",
+                                )
+                                .emit();
+                            error = true;
+                        }
+                    }
+
                     if error {
                         return;
                     }

src/stage0.txt

@@ -12,9 +12,9 @@
 # source tarball for a stable release you'll likely see `1.x.0` for rustc and
 # `0.(x+1).0` for Cargo where they were released on `date`.
 
-date: 2020-07-13
+date: 2020-08-03
-rustc: 1.45.0
+rustc: 1.45.2
-cargo: 0.46.0
+cargo: 0.46.1
 
 # We use a nightly rustfmt to format the source because it solves some
 # bootstrapping issues with use of new syntax in this repo. If you're looking at
@@ -40,4 +40,4 @@ cargo: 0.46.0
 # looking at a beta source tarball and it's uncommented we'll shortly comment it
 # out.
 
-dev: 1
+#dev: 1

src/test/ui/associated-types/defaults-cyclic-fail-1.rs

@@ -26,16 +26,16 @@ impl Tr for u32 {
 
 // ...but only if this actually breaks the cycle
 impl Tr for bool {
-//~^ ERROR overflow evaluating the requirement
+    //~^ ERROR type mismatch resolving `<bool as Tr>::B == _`
     type A = Box<Self::B>;
-    //~^ ERROR overflow evaluating the requirement
+    //~^ ERROR type mismatch resolving `<bool as Tr>::B == _`
 }
 // (the error is shown twice for some reason)
 
 impl Tr for usize {
-//~^ ERROR overflow evaluating the requirement
+    //~^ ERROR type mismatch resolving `<usize as Tr>::B == _`
     type B = &'static Self::A;
-    //~^ ERROR overflow evaluating the requirement
+    //~^ ERROR type mismatch resolving `<usize as Tr>::A == _`
 }
 
 fn main() {

src/test/ui/associated-types/defaults-cyclic-fail-1.stderr

@@ -1,33 +1,34 @@
-error[E0275]: overflow evaluating the requirement `<() as Tr>::B`
+error[E0275]: overflow evaluating the requirement `<() as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-1.rs:10:6
    |
 LL | impl Tr for () {}
    |      ^^
 
-error[E0275]: overflow evaluating the requirement `<bool as Tr>::B`
+error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-1.rs:28:6
    |
 LL | impl Tr for bool {
-   |      ^^
+   |      ^^ cyclic type of infinite size
 
-error[E0275]: overflow evaluating the requirement `<usize as Tr>::B`
+error[E0271]: type mismatch resolving `<usize as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-1.rs:35:6
    |
 LL | impl Tr for usize {
-   |      ^^
+   |      ^^ cyclic type of infinite size
 
-error[E0275]: overflow evaluating the requirement `<bool as Tr>::B`
+error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-1.rs:30:5
    |
 LL |     type A = Box<Self::B>;
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
-error[E0275]: overflow evaluating the requirement `<usize as Tr>::A`
+error[E0271]: type mismatch resolving `<usize as Tr>::A == _`
   --> $DIR/defaults-cyclic-fail-1.rs:37:5
    |
 LL |     type B = &'static Self::A;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
 error: aborting due to 5 previous errors
 
-For more information about this error, try `rustc --explain E0275`.
+Some errors have detailed explanations: E0271, E0275.
+For more information about an error, try `rustc --explain E0271`.

src/test/ui/associated-types/defaults-cyclic-fail-2.rs

@@ -10,7 +10,7 @@ trait Tr {
 
 // ...but is an error in any impl that doesn't override at least one of the defaults
 impl Tr for () {}
-//~^ ERROR overflow evaluating the requirement
+//~^ ERROR type mismatch resolving `<() as Tr>::B == _`
 
 // As soon as at least one is redefined, it works:
 impl Tr for u8 {
@@ -28,16 +28,16 @@ impl Tr for u32 {
 
 // ...but only if this actually breaks the cycle
 impl Tr for bool {
-//~^ ERROR overflow evaluating the requirement
+    //~^ ERROR type mismatch resolving `<bool as Tr>::B == _`
     type A = Box<Self::B>;
-    //~^ ERROR overflow evaluating the requirement
+    //~^ ERROR type mismatch resolving `<bool as Tr>::B == _`
 }
 // (the error is shown twice for some reason)
 
 impl Tr for usize {
-//~^ ERROR overflow evaluating the requirement
+    //~^ ERROR type mismatch resolving `<usize as Tr>::B == _`
     type B = &'static Self::A;
-    //~^ ERROR overflow evaluating the requirement
+    //~^ ERROR type mismatch resolving `<usize as Tr>::A == _`
 }
 
 fn main() {

src/test/ui/associated-types/defaults-cyclic-fail-2.stderr

@@ -1,33 +1,33 @@
-error[E0275]: overflow evaluating the requirement `<() as Tr>::B`
+error[E0271]: type mismatch resolving `<() as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-2.rs:12:6
    |
 LL | impl Tr for () {}
-   |      ^^
+   |      ^^ cyclic type of infinite size
 
-error[E0275]: overflow evaluating the requirement `<bool as Tr>::B`
+error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-2.rs:30:6
    |
 LL | impl Tr for bool {
-   |      ^^
+   |      ^^ cyclic type of infinite size
 
-error[E0275]: overflow evaluating the requirement `<usize as Tr>::B`
+error[E0271]: type mismatch resolving `<usize as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-2.rs:37:6
    |
 LL | impl Tr for usize {
-   |      ^^
+   |      ^^ cyclic type of infinite size
 
-error[E0275]: overflow evaluating the requirement `<bool as Tr>::B`
+error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-2.rs:32:5
    |
 LL |     type A = Box<Self::B>;
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
-error[E0275]: overflow evaluating the requirement `<usize as Tr>::A`
+error[E0271]: type mismatch resolving `<usize as Tr>::A == _`
   --> $DIR/defaults-cyclic-fail-2.rs:39:5
    |
 LL |     type B = &'static Self::A;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
 error: aborting due to 5 previous errors
 
-For more information about this error, try `rustc --explain E0275`.
+For more information about this error, try `rustc --explain E0271`.

src/test/ui/associated-types/normalize-cycle-in-eval-no-region.rs

@@ -0,0 +1,20 @@
+// Case that the fix for #74868 also allowed to compile
+
+// check-pass
+
+trait BoxedDsl {
+    type Output;
+}
+
+impl<T> BoxedDsl for T
+where
+    T: BoxedDsl,
+{
+    type Output = <T as BoxedDsl>::Output;
+}
+
+trait HandleUpdate {}
+
+impl<T> HandleUpdate for T where T: BoxedDsl<Output = ()> {}
+
+fn main() {}

src/test/ui/associated-types/normalize-cycle-in-eval.rs

@@ -0,0 +1,43 @@
+// regression test for #74868
+
+// check-pass
+
+trait BoxedDsl<'a> {
+    type Output;
+}
+
+impl<'a, T> BoxedDsl<'a> for T
+where
+    T: BoxedDsl<'a>,
+{
+    type Output = <T as BoxedDsl<'a>>::Output;
+}
+
+// Showing this trait is wf requires proving
+// Self: HandleUpdate
+//
+// The impl below is a candidate for this projection, as well as the `Self:
+// HandleUpdate` bound in the environment.
+// We evaluate both candidates to see if we need to consider both applicable.
+// Evaluating the impl candidate requires evaluating
+// <T as BoxedDsl<'static>>::Output == ()
+// The above impl cause normalizing the above type normalize to itself.
+//
+// This previously compiled because we would generate a new region
+// variable each time around the cycle, and evaluation would eventually return
+// `EvaluatedToErr` from the `Self: Sized` in the impl, which would in turn
+// leave the bound as the only candidate.
+//
+// #73452 changed this so that region variables are canonicalized when we
+// normalize, which means that the projection cycle is detected before
+// evaluation returns EvaluatedToErr. The cycle resulted in an error being
+// emitted immediately, causing this to fail to compile.
+//
+// To fix this, normalization doesn't directly emit errors when it finds a
+// cycle, instead letting the caller handle it. This restores the original
+// behavior.
+trait HandleUpdate {}
+
+impl<T> HandleUpdate for T where T: BoxedDsl<'static, Output = ()> {}
+
+fn main() {}

src/test/ui/async-await/issue-68523-start.rs

@@ -4,6 +4,6 @@
 
 #[start]
 pub async fn start(_: isize, _: *const *const u8) -> isize {
-//~^ ERROR start is not allowed to be `async`
+//~^ ERROR `start` is not allowed to be `async`
     0
 }

src/test/ui/async-await/issue-68523-start.stderr

@@ -1,8 +1,8 @@
-error[E0752]: start is not allowed to be `async`
+error[E0752]: `start` is not allowed to be `async`
   --> $DIR/issue-68523-start.rs:6:1
    |
 LL | pub async fn start(_: isize, _: *const *const u8) -> isize {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ start is not allowed to be `async`
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `start` is not allowed to be `async`
 
 error: aborting due to previous error
 

src/test/ui/auto-traits/issue-23080-2.rs

@@ -1,5 +1,3 @@
-//~ ERROR
-
 #![feature(optin_builtin_traits)]
 #![feature(negative_impls)]
 

src/test/ui/auto-traits/issue-23080-2.stderr

@@ -1,17 +1,11 @@
 error[E0380]: auto traits cannot have methods or associated items
-  --> $DIR/issue-23080-2.rs:7:10
+  --> $DIR/issue-23080-2.rs:5:10
    |
 LL | unsafe auto trait Trait {
    |                   ----- auto trait cannot have items
 LL |     type Output;
    |          ^^^^^^
 
-error[E0275]: overflow evaluating the requirement `<() as Trait>::Output`
+error: aborting due to previous error
-   |
-   = note: required because of the requirements on the impl of `Trait` for `()`
-   = note: required because of the requirements on the impl of `Trait` for `()`
 
-error: aborting due to 2 previous errors
+For more information about this error, try `rustc --explain E0380`.
-
-Some errors have detailed explanations: E0275, E0380.
-For more information about an error, try `rustc --explain E0275`.

src/test/ui/const_prop/ice-assert-fail-div-by-zero.rs

@@ -1,9 +1,12 @@
 // check-pass
 
+// compile-flags: --crate-type lib
+
+#![warn(unconditional_panic)]
+
 pub struct Fixed64(i64);
 
-pub fn div(f: Fixed64) {
+// HACK: this test passes only because this is a const fn that is written to metadata
-    f.0 / 0;
+pub const fn div(f: Fixed64) {
+    f.0 / 0; //~ WARN will panic at runtime
 }
-
-fn main() {}

src/test/ui/const_prop/ice-assert-fail-div-by-zero.stderr

@@ -0,0 +1,14 @@
+warning: this operation will panic at runtime
+  --> $DIR/ice-assert-fail-div-by-zero.rs:11:5
+   |
+LL |     f.0 / 0;
+   |     ^^^^^^^ attempt to divide _ by zero
+   |
+note: the lint level is defined here
+  --> $DIR/ice-assert-fail-div-by-zero.rs:5:9
+   |
+LL | #![warn(unconditional_panic)]
+   |         ^^^^^^^^^^^^^^^^^^^
+
+warning: 1 warning emitted
+

src/test/ui/consts/unsizing-cast-non-null.rs

@@ -0,0 +1,10 @@
+// Regression test for #75118.
+
+use std::ptr::NonNull;
+
+pub const fn dangling_slice<T>() -> NonNull<[T]> {
+    NonNull::<[T; 0]>::dangling()
+    //~^ ERROR: unsizing casts are only allowed for references right now
+}
+
+fn main() {}

src/test/ui/consts/unsizing-cast-non-null.stderr

@@ -0,0 +1,12 @@
+error[E0723]: unsizing casts are only allowed for references right now
+  --> $DIR/unsizing-cast-non-null.rs:6:5
+   |
+LL |     NonNull::<[T; 0]>::dangling()
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
+   = help: add `#![feature(const_fn)]` to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0723`.

src/test/ui/issues/issue-21946.rs

@@ -5,9 +5,9 @@ trait Foo {
 struct FooStruct;
 
 impl Foo for FooStruct {
-//~^ ERROR overflow evaluating the requirement `<FooStruct as Foo>::A`
+    //~^ ERROR overflow evaluating the requirement `<FooStruct as Foo>::A == _`
     type A = <FooStruct as Foo>::A;
-    //~^ ERROR overflow evaluating the requirement `<FooStruct as Foo>::A`
+    //~^ ERROR overflow evaluating the requirement `<FooStruct as Foo>::A == _`
 }
 
 fn main() {}

src/test/ui/issues/issue-21946.stderr

@@ -1,10 +1,10 @@
-error[E0275]: overflow evaluating the requirement `<FooStruct as Foo>::A`
+error[E0275]: overflow evaluating the requirement `<FooStruct as Foo>::A == _`
   --> $DIR/issue-21946.rs:7:6
    |
 LL | impl Foo for FooStruct {
    |      ^^^
 
-error[E0275]: overflow evaluating the requirement `<FooStruct as Foo>::A`
+error[E0275]: overflow evaluating the requirement `<FooStruct as Foo>::A == _`
   --> $DIR/issue-21946.rs:9:5
    |
 LL |     type A = <FooStruct as Foo>::A;

src/test/ui/issues/issue-23122-1.stderr

@@ -1,10 +1,10 @@
-error[E0275]: overflow evaluating the requirement `<GetNext<T> as Next>::Next`
+error[E0275]: overflow evaluating the requirement `<GetNext<T> as Next>::Next == _`
   --> $DIR/issue-23122-1.rs:7:15
    |
 LL | impl<T: Next> Next for GetNext<T> {
    |               ^^^^
 
-error[E0275]: overflow evaluating the requirement `<GetNext<T> as Next>::Next`
+error[E0275]: overflow evaluating the requirement `<GetNext<T> as Next>::Next == _`
   --> $DIR/issue-23122-1.rs:9:5
    |
 LL |     type Next = <GetNext<T> as Next>::Next;

src/test/ui/issues/issue-73886.rs

@@ -0,0 +1,6 @@
+fn main() {
+    let _ = &&[0] as &[_];
+    //~^ ERROR non-primitive cast: `&&[i32; 1]` as `&[_]`
+    let _ = 7u32 as Option<_>;
+    //~^ ERROR non-primitive cast: `u32` as `std::option::Option<_>`
+}

src/test/ui/issues/issue-73886.stderr

@@ -0,0 +1,15 @@
+error[E0605]: non-primitive cast: `&&[i32; 1]` as `&[_]`
+  --> $DIR/issue-73886.rs:2:13
+   |
+LL |     let _ = &&[0] as &[_];
+   |             ^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
+
+error[E0605]: non-primitive cast: `u32` as `std::option::Option<_>`
+  --> $DIR/issue-73886.rs:4:13
+   |
+LL |     let _ = 7u32 as Option<_>;
+   |             ^^^^^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0605`.

src/test/ui/lint/lint-ctypes-73747.rs

@@ -0,0 +1,14 @@
+// check-pass
+
+#[repr(transparent)]
+struct NonNullRawComPtr<T: ComInterface> {
+    inner: std::ptr::NonNull<<T as ComInterface>::VTable>,
+}
+
+trait ComInterface {
+    type VTable;
+}
+
+extern "C" fn invoke<T: ComInterface>(_: Option<NonNullRawComPtr<T>>) {}
+
+fn main() {}

src/test/ui/lint/lint-ctypes-fn.rs

@@ -71,7 +71,8 @@ pub extern "C" fn str_type(p: &str) { }
 //~^ ERROR: uses type `str`
 
 pub extern "C" fn box_type(p: Box<u32>) { }
-//~^ ERROR uses type `std::boxed::Box<u32>`
+
+pub extern "C" fn opt_box_type(p: Option<Box<u32>>) { }
 
 pub extern "C" fn char_type(p: char) { }
 //~^ ERROR uses type `char`
@@ -106,7 +107,6 @@ pub extern "C" fn fn_type2(p: fn()) { }
 //~^ ERROR uses type `fn()`
 
 pub extern "C" fn fn_contained(p: RustBadRet) { }
-//~^ ERROR: uses type `std::boxed::Box<u32>`
 
 pub extern "C" fn transparent_i128(p: TransparentI128) { }
 //~^ ERROR: uses type `i128`
@@ -115,7 +115,6 @@ pub extern "C" fn transparent_str(p: TransparentStr) { }
 //~^ ERROR: uses type `str`
 
 pub extern "C" fn transparent_fn(p: TransparentBadFn) { }
-//~^ ERROR: uses type `std::boxed::Box<u32>`
 
 pub extern "C" fn good3(fptr: Option<extern fn()>) { }
 

src/test/ui/lint/lint-ctypes-fn.stderr

@@ -21,17 +21,8 @@ LL | pub extern "C" fn str_type(p: &str) { }
    = help: consider using `*const u8` and a length instead
    = note: string slices have no C equivalent
 
-error: `extern` fn uses type `std::boxed::Box<u32>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:73:31
-   |
-LL | pub extern "C" fn box_type(p: Box<u32>) { }
-   |                               ^^^^^^^^ not FFI-safe
-   |
-   = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
-   = note: this struct has unspecified layout
-
 error: `extern` fn uses type `char`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:76:32
+  --> $DIR/lint-ctypes-fn.rs:77:32
    |
 LL | pub extern "C" fn char_type(p: char) { }
    |                                ^^^^ not FFI-safe
@@ -40,7 +31,7 @@ LL | pub extern "C" fn char_type(p: char) { }
    = note: the `char` type has no C equivalent
 
 error: `extern` fn uses type `i128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:79:32
+  --> $DIR/lint-ctypes-fn.rs:80:32
    |
 LL | pub extern "C" fn i128_type(p: i128) { }
    |                                ^^^^ not FFI-safe
@@ -48,7 +39,7 @@ LL | pub extern "C" fn i128_type(p: i128) { }
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` fn uses type `u128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:82:32
+  --> $DIR/lint-ctypes-fn.rs:83:32
    |
 LL | pub extern "C" fn u128_type(p: u128) { }
    |                                ^^^^ not FFI-safe
@@ -56,7 +47,7 @@ LL | pub extern "C" fn u128_type(p: u128) { }
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` fn uses type `(i32, i32)`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:85:33
+  --> $DIR/lint-ctypes-fn.rs:86:33
    |
 LL | pub extern "C" fn tuple_type(p: (i32, i32)) { }
    |                                 ^^^^^^^^^^ not FFI-safe
@@ -65,7 +56,7 @@ LL | pub extern "C" fn tuple_type(p: (i32, i32)) { }
    = note: tuples have unspecified layout
 
 error: `extern` fn uses type `(i32, i32)`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:88:34
+  --> $DIR/lint-ctypes-fn.rs:89:34
    |
 LL | pub extern "C" fn tuple_type2(p: I32Pair) { }
    |                                  ^^^^^^^ not FFI-safe
@@ -74,7 +65,7 @@ LL | pub extern "C" fn tuple_type2(p: I32Pair) { }
    = note: tuples have unspecified layout
 
 error: `extern` fn uses type `ZeroSize`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:91:32
+  --> $DIR/lint-ctypes-fn.rs:92:32
    |
 LL | pub extern "C" fn zero_size(p: ZeroSize) { }
    |                                ^^^^^^^^ not FFI-safe
@@ -88,7 +79,7 @@ LL | pub struct ZeroSize;
    | ^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `ZeroSizeWithPhantomData`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:94:40
+  --> $DIR/lint-ctypes-fn.rs:95:40
    |
 LL | pub extern "C" fn zero_size_phantom(p: ZeroSizeWithPhantomData) { }
    |                                        ^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -101,7 +92,7 @@ LL | pub struct ZeroSizeWithPhantomData(PhantomData<i32>);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `std::marker::PhantomData<bool>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:97:51
+  --> $DIR/lint-ctypes-fn.rs:98:51
    |
 LL | pub extern "C" fn zero_size_phantom_toplevel() -> PhantomData<bool> {
    |                                                   ^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -109,7 +100,7 @@ LL | pub extern "C" fn zero_size_phantom_toplevel() -> PhantomData<bool> {
    = note: composed only of `PhantomData`
 
 error: `extern` fn uses type `fn()`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:102:30
+  --> $DIR/lint-ctypes-fn.rs:103:30
    |
 LL | pub extern "C" fn fn_type(p: RustFn) { }
    |                              ^^^^^^ not FFI-safe
@@ -118,7 +109,7 @@ LL | pub extern "C" fn fn_type(p: RustFn) { }
    = note: this function pointer has Rust-specific calling convention
 
 error: `extern` fn uses type `fn()`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:105:31
+  --> $DIR/lint-ctypes-fn.rs:106:31
    |
 LL | pub extern "C" fn fn_type2(p: fn()) { }
    |                               ^^^^ not FFI-safe
@@ -126,15 +117,6 @@ LL | pub extern "C" fn fn_type2(p: fn()) { }
    = help: consider using an `extern fn(...) -> ...` function pointer instead
    = note: this function pointer has Rust-specific calling convention
 
-error: `extern` fn uses type `std::boxed::Box<u32>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:108:35
-   |
-LL | pub extern "C" fn fn_contained(p: RustBadRet) { }
-   |                                   ^^^^^^^^^^ not FFI-safe
-   |
-   = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
-   = note: this struct has unspecified layout
-
 error: `extern` fn uses type `i128`, which is not FFI-safe
   --> $DIR/lint-ctypes-fn.rs:111:39
    |
@@ -152,17 +134,8 @@ LL | pub extern "C" fn transparent_str(p: TransparentStr) { }
    = help: consider using `*const u8` and a length instead
    = note: string slices have no C equivalent
 
-error: `extern` fn uses type `std::boxed::Box<u32>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:117:37
-   |
-LL | pub extern "C" fn transparent_fn(p: TransparentBadFn) { }
-   |                                     ^^^^^^^^^^^^^^^^ not FFI-safe
-   |
-   = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
-   = note: this struct has unspecified layout
-
 error: `extern` fn uses type `std::marker::PhantomData<bool>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:161:43
+  --> $DIR/lint-ctypes-fn.rs:160:43
    |
 LL | pub extern "C" fn unused_generic2<T>() -> PhantomData<bool> {
    |                                           ^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -170,7 +143,7 @@ LL | pub extern "C" fn unused_generic2<T>() -> PhantomData<bool> {
    = note: composed only of `PhantomData`
 
 error: `extern` fn uses type `std::vec::Vec<T>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:174:39
+  --> $DIR/lint-ctypes-fn.rs:173:39
    |
 LL | pub extern "C" fn used_generic4<T>(x: Vec<T>) { }
    |                                       ^^^^^^ not FFI-safe
@@ -179,7 +152,7 @@ LL | pub extern "C" fn used_generic4<T>(x: Vec<T>) { }
    = note: this struct has unspecified layout
 
 error: `extern` fn uses type `std::vec::Vec<T>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:177:41
+  --> $DIR/lint-ctypes-fn.rs:176:41
    |
 LL | pub extern "C" fn used_generic5<T>() -> Vec<T> {
    |                                         ^^^^^^ not FFI-safe
@@ -187,5 +160,5 @@ LL | pub extern "C" fn used_generic5<T>() -> Vec<T> {
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 
-error: aborting due to 20 previous errors
+error: aborting due to 17 previous errors
 

src/test/ui/lint/lint-ctypes.rs

@@ -48,6 +48,8 @@ extern {
     pub fn slice_type(p: &[u32]); //~ ERROR: uses type `[u32]`
     pub fn str_type(p: &str); //~ ERROR: uses type `str`
     pub fn box_type(p: Box<u32>); //~ ERROR uses type `std::boxed::Box<u32>`
+    pub fn opt_box_type(p: Option<Box<u32>>);
+    //~^ ERROR uses type `std::option::Option<std::boxed::Box<u32>>`
     pub fn char_type(p: char); //~ ERROR uses type `char`
     pub fn i128_type(p: i128); //~ ERROR uses type `i128`
     pub fn u128_type(p: u128); //~ ERROR uses type `u128`

src/test/ui/lint/lint-ctypes.stderr

@@ -58,8 +58,17 @@ LL |     pub fn box_type(p: Box<u32>);
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 
+error: `extern` block uses type `std::option::Option<std::boxed::Box<u32>>`, which is not FFI-safe
+  --> $DIR/lint-ctypes.rs:51:28
+   |
+LL |     pub fn opt_box_type(p: Option<Box<u32>>);
+   |                            ^^^^^^^^^^^^^^^^ not FFI-safe
+   |
+   = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
+   = note: enum has no representation hint
+
 error: `extern` block uses type `char`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:51:25
+  --> $DIR/lint-ctypes.rs:53:25
    |
 LL |     pub fn char_type(p: char);
    |                         ^^^^ not FFI-safe
@@ -68,7 +77,7 @@ LL |     pub fn char_type(p: char);
    = note: the `char` type has no C equivalent
 
 error: `extern` block uses type `i128`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:52:25
+  --> $DIR/lint-ctypes.rs:54:25
    |
 LL |     pub fn i128_type(p: i128);
    |                         ^^^^ not FFI-safe
@@ -76,7 +85,7 @@ LL |     pub fn i128_type(p: i128);
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `u128`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:53:25
+  --> $DIR/lint-ctypes.rs:55:25
    |
 LL |     pub fn u128_type(p: u128);
    |                         ^^^^ not FFI-safe
@@ -84,7 +93,7 @@ LL |     pub fn u128_type(p: u128);
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `dyn std::clone::Clone`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:54:26
+  --> $DIR/lint-ctypes.rs:56:26
    |
 LL |     pub fn trait_type(p: &dyn Clone);
    |                          ^^^^^^^^^^ not FFI-safe
@@ -92,7 +101,7 @@ LL |     pub fn trait_type(p: &dyn Clone);
    = note: trait objects have no C equivalent
 
 error: `extern` block uses type `(i32, i32)`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:55:26
+  --> $DIR/lint-ctypes.rs:57:26
    |
 LL |     pub fn tuple_type(p: (i32, i32));
    |                          ^^^^^^^^^^ not FFI-safe
@@ -101,7 +110,7 @@ LL |     pub fn tuple_type(p: (i32, i32));
    = note: tuples have unspecified layout
 
 error: `extern` block uses type `(i32, i32)`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:56:27
+  --> $DIR/lint-ctypes.rs:58:27
    |
 LL |     pub fn tuple_type2(p: I32Pair);
    |                           ^^^^^^^ not FFI-safe
@@ -110,7 +119,7 @@ LL |     pub fn tuple_type2(p: I32Pair);
    = note: tuples have unspecified layout
 
 error: `extern` block uses type `ZeroSize`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:57:25
+  --> $DIR/lint-ctypes.rs:59:25
    |
 LL |     pub fn zero_size(p: ZeroSize);
    |                         ^^^^^^^^ not FFI-safe
@@ -124,7 +133,7 @@ LL | pub struct ZeroSize;
    | ^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` block uses type `ZeroSizeWithPhantomData`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:58:33
+  --> $DIR/lint-ctypes.rs:60:33
    |
 LL |     pub fn zero_size_phantom(p: ZeroSizeWithPhantomData);
    |                                 ^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -137,7 +146,7 @@ LL | pub struct ZeroSizeWithPhantomData(::std::marker::PhantomData<i32>);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` block uses type `std::marker::PhantomData<bool>`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:61:12
+  --> $DIR/lint-ctypes.rs:63:12
    |
 LL |         -> ::std::marker::PhantomData<bool>;
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -145,7 +154,7 @@ LL |         -> ::std::marker::PhantomData<bool>;
    = note: composed only of `PhantomData`
 
 error: `extern` block uses type `fn()`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:62:23
+  --> $DIR/lint-ctypes.rs:64:23
    |
 LL |     pub fn fn_type(p: RustFn);
    |                       ^^^^^^ not FFI-safe
@@ -154,7 +163,7 @@ LL |     pub fn fn_type(p: RustFn);
    = note: this function pointer has Rust-specific calling convention
 
 error: `extern` block uses type `fn()`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:63:24
+  --> $DIR/lint-ctypes.rs:65:24
    |
 LL |     pub fn fn_type2(p: fn());
    |                        ^^^^ not FFI-safe
@@ -163,7 +172,7 @@ LL |     pub fn fn_type2(p: fn());
    = note: this function pointer has Rust-specific calling convention
 
 error: `extern` block uses type `std::boxed::Box<u32>`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:64:28
+  --> $DIR/lint-ctypes.rs:66:28
    |
 LL |     pub fn fn_contained(p: RustBadRet);
    |                            ^^^^^^^^^^ not FFI-safe
@@ -172,7 +181,7 @@ LL |     pub fn fn_contained(p: RustBadRet);
    = note: this struct has unspecified layout
 
 error: `extern` block uses type `i128`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:65:32
+  --> $DIR/lint-ctypes.rs:67:32
    |
 LL |     pub fn transparent_i128(p: TransparentI128);
    |                                ^^^^^^^^^^^^^^^ not FFI-safe
@@ -180,7 +189,7 @@ LL |     pub fn transparent_i128(p: TransparentI128);
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `str`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:66:31
+  --> $DIR/lint-ctypes.rs:68:31
    |
 LL |     pub fn transparent_str(p: TransparentStr);
    |                               ^^^^^^^^^^^^^^ not FFI-safe
@@ -189,7 +198,7 @@ LL |     pub fn transparent_str(p: TransparentStr);
    = note: string slices have no C equivalent
 
 error: `extern` block uses type `std::boxed::Box<u32>`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:67:30
+  --> $DIR/lint-ctypes.rs:69:30
    |
 LL |     pub fn transparent_fn(p: TransparentBadFn);
    |                              ^^^^^^^^^^^^^^^^ not FFI-safe
@@ -198,7 +207,7 @@ LL |     pub fn transparent_fn(p: TransparentBadFn);
    = note: this struct has unspecified layout
 
 error: `extern` block uses type `[u8; 8]`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:68:27
+  --> $DIR/lint-ctypes.rs:70:27
    |
 LL |     pub fn raw_array(arr: [u8; 8]);
    |                           ^^^^^^^ not FFI-safe
@@ -207,7 +216,7 @@ LL |     pub fn raw_array(arr: [u8; 8]);
    = note: passing raw arrays by value is not FFI-safe
 
 error: `extern` block uses type `u128`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:70:34
+  --> $DIR/lint-ctypes.rs:72:34
    |
 LL |     pub static static_u128_type: u128;
    |                                  ^^^^ not FFI-safe
@@ -215,12 +224,12 @@ LL |     pub static static_u128_type: u128;
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `u128`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:71:40
+  --> $DIR/lint-ctypes.rs:73:40
    |
 LL |     pub static static_u128_array_type: [u128; 16];
    |                                        ^^^^^^^^^^ not FFI-safe
    |
    = note: 128-bit integers don't currently have a known stable ABI
 
-error: aborting due to 23 previous errors
+error: aborting due to 24 previous errors
 

src/test/ui/mir/issue-75419-validation-impl-trait.rs

@@ -0,0 +1,13 @@
+// build-pass
+
+// This used to fail MIR validation due to the types on both sides of
+// an assignment not being equal.
+// The failure doesn't occur with a check-only build.
+
+fn iter_slice<'a, T>(xs: &'a [T]) -> impl Iterator<Item = &'a T> {
+    xs.iter()
+}
+
+fn main() {
+    iter_slice::<()> as fn(_) -> _;
+}

src/test/ui/regions/type-param-outlives-reempty-issue-74429-2.rs

@@ -0,0 +1,66 @@
+// Regression test for #74429, where we didn't think that a type parameter
+// outlived `ReEmpty`.
+
+// check-pass
+
+use std::marker::PhantomData;
+use std::ptr::NonNull;
+
+pub unsafe trait RawData {
+    type Elem;
+}
+
+unsafe impl<A> RawData for OwnedRepr<A> {
+    type Elem = A;
+}
+
+unsafe impl<'a, A> RawData for ViewRepr<&'a A> {
+    type Elem = A;
+}
+
+pub struct OwnedRepr<A> {
+    ptr: PhantomData<A>,
+}
+
+// these Copy impls are not necessary for the repro, but allow the code to compile without error
+// on 1.44.1
+#[derive(Copy, Clone)]
+pub struct ViewRepr<A> {
+    life: PhantomData<A>,
+}
+
+#[derive(Copy, Clone)]
+pub struct ArrayBase<S>
+where
+    S: RawData,
+{
+    ptr: NonNull<S::Elem>,
+}
+
+pub type Array<A> = ArrayBase<OwnedRepr<A>>;
+
+pub type ArrayView<'a, A> = ArrayBase<ViewRepr<&'a A>>;
+
+impl<A, S> ArrayBase<S>
+where
+    S: RawData<Elem = A>,
+{
+    pub fn index_axis(&self) -> ArrayView<'_, A> {
+        unimplemented!()
+    }
+
+    pub fn axis_iter<'a>(&'a self) -> std::iter::Empty<&'a A> {
+        unimplemented!()
+    }
+}
+
+pub fn x<T: Copy>(a: Array<T>) {
+    // drop just avoids a must_use warning
+    drop((0..1).filter(|_| true));
+    let y = a.index_axis();
+    a.axis_iter().for_each(|_| {
+        drop(y);
+    });
+}
+
+fn main() {}

src/test/ui/regions/type-param-outlives-reempty-issue-74429.rs

@@ -0,0 +1,35 @@
+// Regression test for #74429, where we didn't think that a type parameter
+// outlived `ReEmpty`.
+
+// check-pass
+
+use std::marker::PhantomData;
+
+fn apply<T, F: FnOnce(T)>(_: T, _: F) {}
+
+#[derive(Clone, Copy)]
+struct Invariant<T> {
+    t: T,
+    p: PhantomData<fn(T) -> T>,
+}
+
+fn verify_reempty<T>(x: T) {
+    // r is inferred to have type `Invariant<&ReEmpty(U0) T>`
+    let r = Invariant { t: &x, p: PhantomData };
+    // Creates a new universe, all variables from now on are in `U1`, say.
+    let _: fn(&()) = |_| {};
+    // Closure parameter is of type `&ReEmpty(U1) T`, so the closure has an implied
+    // bound of `T: ReEmpty(U1)`
+    apply(&x, |_| {
+        // Requires `typeof(r)` is well-formed, i.e. `T: ReEmpty(U0)`. If we
+        // only have the implied bound from the closure parameter to use this
+        // requires `ReEmpty(U1): ReEmpty(U0)`, which isn't true so we reported
+        // an error.
+        //
+        // This doesn't happen any more because we ensure that `T: ReEmpty(U0)`
+        // is an implicit bound for all type parameters.
+        drop(r);
+    });
+}
+
+fn main() {}

src/test/ui/rfc-2091-track-caller/error-with-main.rs

@@ -0,0 +1,4 @@
+#[track_caller] //~ ERROR `main` function is not allowed to be
+fn main() {
+    panic!("{}: oh no", std::panic::Location::caller());
+}

src/test/ui/rfc-2091-track-caller/error-with-main.stderr

@@ -0,0 +1,12 @@
+error: `main` function is not allowed to be `#[track_caller]`
+  --> $DIR/error-with-main.rs:1:1
+   |
+LL |   #[track_caller]
+   |   ^^^^^^^^^^^^^^^
+LL | / fn main() {
+LL | |     panic!("{}: oh no", std::panic::Location::caller());
+LL | | }
+   | |_- `main` function is not allowed to be `#[track_caller]`
+
+error: aborting due to previous error
+

src/test/ui/rfc-2091-track-caller/error-with-start.rs

@@ -0,0 +1,7 @@
+#![feature(start)]
+
+#[start]
+#[track_caller] //~ ERROR `start` is not allowed to be `#[track_caller]`
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+    panic!("{}: oh no", std::panic::Location::caller());
+}

src/test/ui/rfc-2091-track-caller/error-with-start.stderr

@@ -0,0 +1,12 @@
+error: `start` is not allowed to be `#[track_caller]`
+  --> $DIR/error-with-start.rs:4:1
+   |
+LL |   #[track_caller]
+   |   ^^^^^^^^^^^^^^^
+LL | / fn start(_argc: isize, _argv: *const *const u8) -> isize {
+LL | |     panic!("{}: oh no", std::panic::Location::caller());
+LL | | }
+   | |_- `start` is not allowed to be `#[track_caller]`
+
+error: aborting due to previous error
+

src/test/ui/rfc-2091-track-caller/tracked-trait-obj.rs

@@ -0,0 +1,23 @@
+// run-pass
+
+trait Tracked {
+    #[track_caller]
+    fn handle(&self) {
+        let location = std::panic::Location::caller();
+        assert_eq!(location.file(), file!());
+        // we only call this via trait object, so the def site should *always* be returned
+        assert_eq!(location.line(), line!() - 4);
+        assert_eq!(location.column(), 5);
+    }
+}
+
+impl Tracked for () {}
+impl Tracked for u8 {}
+
+fn main() {
+    let tracked: &dyn Tracked = &5u8;
+    tracked.handle();
+
+    const TRACKED: &dyn Tracked = &();
+    TRACKED.handle();
+}

src/test/ui/typeck/issue-74933.rs

@@ -0,0 +1,38 @@
+// check-pass
+//
+// rust-lang/rust#74933: Lifetime error when indexing with borrowed index
+
+use std::ops::{Index, IndexMut};
+
+struct S(V);
+struct K<'a>(&'a ());
+struct V;
+
+impl<'a> Index<&'a K<'a>> for S {
+    type Output = V;
+
+    fn index(&self, _: &'a K<'a>) -> &V {
+        &self.0
+    }
+}
+
+impl<'a> IndexMut<&'a K<'a>> for S {
+    fn index_mut(&mut self, _: &'a K<'a>) -> &mut V {
+        &mut self.0
+    }
+}
+
+impl V {
+    fn foo(&mut self) {}
+}
+
+fn test(s: &mut S, k: &K<'_>) {
+    s[k] = V;
+    s[k].foo();
+}
+
+fn main() {
+    let mut s = S(V);
+    let k = K(&());
+    test(&mut s, &k);
+}

src/tools/publish_toolstate.py

@@ -32,8 +32,7 @@ MAINTAINERS = {
     'reference': {'steveklabnik', 'Havvy', 'matthewjasper', 'ehuss'},
     'rust-by-example': {'steveklabnik', 'marioidival'},
     'embedded-book': {
-        'adamgreig', 'andre-richter', 'jamesmunns', 'korken89',
+        'adamgreig', 'andre-richter', 'jamesmunns', 'therealprof',
-        'ryankurte', 'thejpster', 'therealprof',
     },
     'edition-guide': {'ehuss', 'steveklabnik'},
     'rustc-dev-guide': {'mark-i-m', 'spastorino', 'amanjeev', 'JohnTitor'},

version

@@ -1 +1 @@
-1.46.0-beta.2 (6f959902b 2020-07-23)
+1.46.0 (04488afe3 2020-08-24)