Remove a back-compat hack on lazy TAIT by JohnTitor · Pull Request #97346 · rust-lang/rust (original) (raw)

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This PR's motivation is here: #72614 (comment)
But removing a hack doesn't seem to reject the code on the issue, there're some more hacks?
r? @oli-obk

rustbot added the T-compiler

Relevant to the compiler team, which will review and decide on the PR/issue.

label

May 24, 2022

But removing a hack doesn't seem to reject the code on the issue, there're some more hacks?

Oh... Turns out I didn't read your example test very well. Yea, that's totally fine to pass. There were other roundabout ways to make the same thing pass before.

So independently of that issue, we can still remove the back compat hack and see how well/bad it goes

Alright, dropped the test as it's unrelated to the hack itself.

Oh... Turns out I didn't read your example test very well. Yea, that's totally fine to pass. There were other roundabout ways to make the same thing pass before.

Is there any reference/discussion etc. to that? To close #72614, I'd like to know how these impl traits work!

So independently of that issue, we can still remove the back compat hack and see how well/bad it goes

Feel free to kick off crater once you're ready, I'm not familiar with it.

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This may still be necessary as a performance optimization

⌛ Trying commit c46eea9c5b7f87152efb7b76f1ceba0f2b165e6c with merge 7306d3110618f84a6a4662b9e2cc4fd0d9b02da8...

Is there any reference/discussion etc. to that? To close #72614, I'd like to know how these impl traits work!

Not really, but I'll leave a comment on that issue explaining what the heck is going on

☀️ Try build successful - checks-actions
Build commit: 7306d3110618f84a6a4662b9e2cc4fd0d9b02da8 (7306d3110618f84a6a4662b9e2cc4fd0d9b02da8)

👌 Experiment pr-97346 created and queued.
🤖 Automatically detected try build 7306d3110618f84a6a4662b9e2cc4fd0d9b02da8
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ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

🚧 Experiment pr-97346 is now running

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

@oli-obk We have a ton of spurious-regressed, is it okay?

Some analysis of "root results" failures:

• stuartZhang.scaffold-wizard.ae8617257ead4fb6fc1e529f192fc4ccbe3806c6: Seems unrelated
• Ayrx.binja-rs-hello-world.a0f5fb90a3544b233856cddbdac059da21ce27ee: Seems unrelated
• ledger-transport-zemu-0.9.0: Seems unrelated
• bitrust-0.1.0: Seems unrelated
• andrewhickman.proxy-server.1f02e7d8fafb8f43059ae0313f5dc3ca64cee637: Seems related but the crate has not been updated since 2020 Sep. 8th
• battjt.cb-test.b23d7048a84aa9f1e407edb24fddc001794e31d6: Seems unrelated, the issue has been reported as error: internal compiler error: compiler/rustc_passes/src/dead.rs:122:13: no type-dependent def for method #88643 and it's fixed on master

I think all of the "regressed: dependencies" failures are due to a lack of mem.
So I'd like to say that the impact of this change would be pretty small (if we could ignore the "spurious-regressed" failures).
Thoughts?

Yea, except for proxy-server, all of these are unrelated. I guess we can break them as long as we open an issue or fix PR on their repo

JohnTitor added a commit to JohnTitor/mock-server that referenced this pull request

Jun 16, 2022

Signed-off-by: Yuki Okushi jtitor@2k36.org

andrewhickman added a commit to andrewhickman/mock-server that referenced this pull request

Jun 16, 2022

oli-obk added T-types

Relevant to the types team, which will review and decide on the PR/issue.

and removed T-compiler

Relevant to the compiler team, which will review and decide on the PR/issue.

labels

Jun 16, 2022

📌 Commit c24f063 has been approved by oli-obk

bors added S-waiting-on-bors

Status: Waiting on bors to run and complete tests. Bors will change the label on completion.

and removed S-waiting-on-author

Status: This is awaiting some action (such as code changes or more information) from the author.

labels

Jun 27, 2022

Dylan-DPC added a commit to Dylan-DPC/rust that referenced this pull request

Jun 28, 2022

… r=oli-obk

Remove a back-compat hack on lazy TAIT

This PR's motivation is here: rust-lang#72614 (comment) But removing a hack doesn't seem to reject the code on the issue, there're some more hacks? r? @oli-obk

bors added a commit to rust-lang-ci/rust that referenced this pull request

Jun 28, 2022

oli-obk added a commit to oli-obk/rust that referenced this pull request

Jul 28, 2022

…t-hacks, r=oli-obk"

This reverts commit c703d11, reversing changes made to 64eb9ab.

bors added a commit to rust-lang-ci/rust that referenced this pull request

Aug 18, 2022

Revert "Rollup merge of rust-lang#97346 - JohnTitor:remove-back-compat-hacks, …

…r=oli-obk"

This reverts commit c703d11, reversing changes made to 64eb9ab.

it didn't apply cleanly, so now it works the same for RPIT and for TAIT instead of just working for RPIT, but we should keep those in sync anyway. It also exposed a TAIT bug (see the feature gated test that now ICEs).

r? @pnkfelix

fixes rust-lang#99536

ehuss pushed a commit to ehuss/rust that referenced this pull request

Aug 31, 2022

Revert "Rollup merge of rust-lang#97346 - JohnTitor:remove-back-compat-hacks, …

…r=oli-obk"

This reverts commit c703d11, reversing changes made to 64eb9ab.

it didn't apply cleanly, so now it works the same for RPIT and for TAIT instead of just working for RPIT, but we should keep those in sync anyway. It also exposed a TAIT bug (see the feature gated test that now ICEs).

r? @pnkfelix

fixes rust-lang#99536

ehuss mentioned this pull request

Aug 31, 2022

ehuss added beta-accepted

Accepted for backporting to the compiler in the beta channel.

and removed beta-accepted

Accepted for backporting to the compiler in the beta channel.

labels

Aug 31, 2022

bors added a commit to rust-lang-ci/rust that referenced this pull request

Aug 31, 2022

wip-sync pushed a commit to NetBSD/pkgsrc-wip that referenced this pull request

Oct 11, 2022

Pkgsrc changes:

• Add patch to fix vendor/kqueue issue (on 32-bit hosts)
• Adjust other patches & line numbers
• Version bumps & checksum changes.

Upstream changes:

Version 1.64.0 (2022-09-22)

Language

• Unions with mutable references or tuples of allowed types are now allowed

• It is now considered valid to deallocate memory pointed to by a shared reference &T if every byte in T is inside an UnsafeCell

• Unused tuple struct fields are now warned against in an allow-by-default lint, [unused_tuple_struct_fields] (rust-lang/rust#95977), similar to the existing warning for unused struct fields. This lint will become warn-by-default in the future.

Compiler

• [Add Nintendo Switch as tier 3 target] (rust-lang/rust#88991)
  • Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support.
• [Only compile #[used] as llvm.compiler.used for ELF targets] (rust-lang/rust#93718)
• [Add the --diagnostic-width compiler flag to define the terminal width.] (rust-lang/rust#95635)
• [Add support for link-flavor rust-lld for iOS, tvOS and watchOS] (rust-lang/rust#98771)

Libraries

• [Remove restrictions on compare-exchange memory ordering.] (rust-lang/rust#98383)
• You can now write! or writeln! into an OsString: Implement fmt::Write for OsString
• [Make RwLockReadGuard covariant] (rust-lang/rust#96820)
• [Implement FusedIterator for std:🥅:[Into]Incoming] (rust-lang/rust#97300)
• [impl<T: AsRawFd> AsRawFd for {Arc,Box}<T>] (rust-lang/rust#97437)
• [ptr::copy and ptr::swap are doing untyped copies] (rust-lang/rust#97712)
• [Add cgroupv1 support to available_parallelism] (rust-lang/rust#97925)
• [Mitigate many incorrect uses of mem::uninitialized] (rust-lang/rust#99182)

Stabilized APIs

• [future::IntoFuture] (https://doc.rust-lang.org/stable/std/future/trait.IntoFuture.html)
• [future::poll_fn] (https://doc.rust-lang.org/stable/std/future/fn.poll_fn.html)
• [task::ready!] (https://doc.rust-lang.org/stable/std/task/macro.ready.html)
• [num::NonZero*::checked_mul] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.checked_mul)
• [num::NonZero*::checked_pow] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.checked_pow)
• [num::NonZero*::saturating_mul] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.saturating_mul)
• [num::NonZero*::saturating_pow] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.saturating_pow)
• [num::NonZeroI*::abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.abs)
• [num::NonZeroI*::checked_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.checked_abs)
• [num::NonZeroI*::overflowing_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.overflowing_abs)
• [num::NonZeroI*::saturating_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.saturating_abs)
• [num::NonZeroI*::unsigned_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.unsigned_abs)
• [num::NonZeroI*::wrapping_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.wrapping_abs)
• [num::NonZeroU*::checked_add] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.checked_add)
• [num::NonZeroU*::checked_next_power_of_two] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.checked_next_power_of_two)
• [num::NonZeroU*::saturating_add] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.saturating_add)
• [os::unix::process::CommandExt::process_group] (https://doc.rust-lang.org/stable/std/os/unix/process/trait.CommandExt.html#tymethod.process_group)
• [os::windows::fs::FileTypeExt::is_symlink_dir] (https://doc.rust-lang.org/stable/std/os/windows/fs/trait.FileTypeExt.html#tymethod.is_symlink_dir)
• [os::windows::fs::FileTypeExt::is_symlink_file] (https://doc.rust-lang.org/stable/std/os/windows/fs/trait.FileTypeExt.html#tymethod.is_symlink_file)

These types were previously stable in std::ffi, but are now also available in core and alloc:

• [core::ffi::CStr] (https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html)
• [core::ffi::FromBytesWithNulError] (https://doc.rust-lang.org/stable/core/ffi/struct.FromBytesWithNulError.html)
• [alloc::ffi::CString] (https://doc.rust-lang.org/stable/alloc/ffi/struct.CString.html)
• [alloc::ffi::FromVecWithNulError] (https://doc.rust-lang.org/stable/alloc/ffi/struct.FromVecWithNulError.html)
• [alloc::ffi::IntoStringError] (https://doc.rust-lang.org/stable/alloc/ffi/struct.IntoStringError.html)
• [alloc::ffi::NulError] (https://doc.rust-lang.org/stable/alloc/ffi/struct.NulError.html)

These types were previously stable in std::os::raw, but are now also available in core::ffi and std::ffi:

• [ffi::c_char] (https://doc.rust-lang.org/stable/std/ffi/type.c_char.html)
• [ffi::c_double] (https://doc.rust-lang.org/stable/std/ffi/type.c_double.html)
• [ffi::c_float] (https://doc.rust-lang.org/stable/std/ffi/type.c_float.html)
• [ffi::c_int] (https://doc.rust-lang.org/stable/std/ffi/type.c_int.html)
• [ffi::c_long] (https://doc.rust-lang.org/stable/std/ffi/type.c_long.html)
• [ffi::c_longlong] (https://doc.rust-lang.org/stable/std/ffi/type.c_longlong.html)
• [ffi::c_schar] (https://doc.rust-lang.org/stable/std/ffi/type.c_schar.html)
• [ffi::c_short] (https://doc.rust-lang.org/stable/std/ffi/type.c_short.html)
• [ffi::c_uchar] (https://doc.rust-lang.org/stable/std/ffi/type.c_uchar.html)
• [ffi::c_uint] (https://doc.rust-lang.org/stable/std/ffi/type.c_uint.html)
• [ffi::c_ulong] (https://doc.rust-lang.org/stable/std/ffi/type.c_ulong.html)
• [ffi::c_ulonglong] (https://doc.rust-lang.org/stable/std/ffi/type.c_ulonglong.html)
• [ffi::c_ushort] (https://doc.rust-lang.org/stable/std/ffi/type.c_ushort.html)

These APIs are now usable in const contexts:

• [slice::from_raw_parts] (https://doc.rust-lang.org/stable/core/slice/fn.from_raw_parts.html)

Cargo

• [Packages can now inherit settings from the workspace so that the settings can be centralized in one place.] (rust-lang/cargo#10859) See workspace.package and workspace.dependencies for more details on how to define these common settings.
• [Cargo commands can now accept multiple --target flags to build for multiple targets at once] (rust-lang/cargo#10766), and the build.target config option may now take an array of multiple targets.
• [The --jobs argument can now take a negative number to count backwards from the max CPUs.] (rust-lang/cargo#10844)
• [cargo add will now update Cargo.lock.] (rust-lang/cargo#10902)
• Added the --crate-type flag to cargo rustc to override the crate type.
• [Significantly improved the performance fetching git dependencies from GitHub when using a hash in the rev field.] (rust-lang/cargo#10079)

Misc

• [The rust-analyzer rustup component is now available on the stable channel.] (rust-lang/rust#98640)

Compatibility Notes

• The minimum required versions for all -linux-gnu targets are now at least kernel 3.2 and glibc 2.17, for targets that previously supported older versions: Increase the minimum linux-gnu versions
• [Network primitives are now implemented with the ideal Rust layout, not the C system layout] (rust-lang/rust#78802). This can cause problems when transmuting the types.
• [Add assertion that transmute_copy's U is not larger than T] (rust-lang/rust#98839)
• [A soundness bug in BTreeMap was fixed] (rust-lang/rust#99413) that allowed data it was borrowing to be dropped before the container.
• [The Drop behavior of C-like enums cast to ints has changed] (rust-lang/rust#96862). These are already discouraged by a compiler warning.
• [Relate late-bound closure lifetimes to parent fn in NLL] (rust-lang/rust#98835)
• [Errors at const-eval time are now in future incompatibility reports] (rust-lang/rust#97743)
• On the thumbv6m-none-eabi target, some incorrect asm! statements were erroneously accepted if they used the high registers (r8 to r14) as an input/output operand. [This is no longer accepted] (rust-lang/rust#99155).
• [impl Trait was accidentally accepted as the associated type value of return-position impl Trait] (rust-lang/rust#97346), without fulfilling all the trait bounds of that associated type, as long as the hidden type satisfies said bounds. This has been fixed.

Internal Changes

These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.

• Windows builds now use profile-guided optimization, providing 10-20% improvements to compiler performance: [Utilize PGO for windows x64 rustc dist builds] (rust-lang/rust#96978)
• [Stop keeping metadata in memory before writing it to disk] (rust-lang/rust#96544)
• [compiletest: strip debuginfo by default for mode=ui] (rust-lang/rust#98140)
• Many improvements to generated code for derives, including performance improvements:
  • [Don't use match-destructuring for derived ops on structs.] (rust-lang/rust#98446)
  • [Many small deriving cleanups] (rust-lang/rust#98741)
  • [More derive output improvements] (rust-lang/rust#98758)
  • Clarify deriving code
  • [Final derive output improvements] (rust-lang/rust#99046)
  • Stop injecting #[allow(unused_qualifications)] in generated derive implementations
  • Improve derive(Debug)
• Bump to clap 3
• fully move dropck to mir
• [Optimize Vec::insert for the case where index == len.] (rust-lang/rust#98755)
• [Convert rust-analyzer to an in-tree tool] (rust-lang/rust#99603)

netbsd-srcmastr pushed a commit to NetBSD/pkgsrc that referenced this pull request

Nov 16, 2022

Pkgsrc changes:

• This package now contains rust-analyzer, so implicitly conflicts with that pkgsrc package. The same goes for the rust-src package.
• Add NetBSD/arm6 port
• Add unfinished NetBSD/mipsel port
• Revert the use of the internal LLVM, should now build with the new pkgsrc LLVM (15).
• Add depndence on compat80 for sparc64 to fix the build
• Adapt patches
• Add CHECK_INTERPRETER_SKIP for a few (mostly unused) files. (A proper fix may come later.)

Upstream changes:

Version 1.64.0 (2022-09-22)

Language

• Unions with mutable references or tuples of allowed types are now allowed

• It is now considered valid to deallocate memory pointed to by a shared reference &T if every byte in T is inside an UnsafeCell

• Unused tuple struct fields are now warned against in an allow-by-default lint, [unused_tuple_struct_fields] (rust-lang/rust#95977), similar to the existing warning for unused struct fields. This lint will become warn-by-default in the future.

Compiler

• [Add Nintendo Switch as tier 3 target] (rust-lang/rust#88991)
  • Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support.
• [Only compile #[used] as llvm.compiler.used for ELF targets] (rust-lang/rust#93718)
• [Add the --diagnostic-width compiler flag to define the terminal width.] (rust-lang/rust#95635)
• [Add support for link-flavor rust-lld for iOS, tvOS and watchOS] (rust-lang/rust#98771)

Libraries

• [Remove restrictions on compare-exchange memory ordering.] (rust-lang/rust#98383)
• You can now write! or writeln! into an OsString: Implement fmt::Write for OsString
• [Make RwLockReadGuard covariant] (rust-lang/rust#96820)
• [Implement FusedIterator for std:🥅:[Into]Incoming] (rust-lang/rust#97300)
• [impl<T: AsRawFd> AsRawFd for {Arc,Box}<T>] (rust-lang/rust#97437)
• [ptr::copy and ptr::swap are doing untyped copies] (rust-lang/rust#97712)
• [Add cgroupv1 support to available_parallelism] (rust-lang/rust#97925)
• [Mitigate many incorrect uses of mem::uninitialized] (rust-lang/rust#99182)

Stabilized APIs

• [future::IntoFuture] (https://doc.rust-lang.org/stable/std/future/trait.IntoFuture.html)
• [future::poll_fn] (https://doc.rust-lang.org/stable/std/future/fn.poll_fn.html)
• [task::ready!] (https://doc.rust-lang.org/stable/std/task/macro.ready.html)
• [num::NonZero*::checked_mul] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.checked_mul)
• [num::NonZero*::checked_pow] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.checked_pow)
• [num::NonZero*::saturating_mul] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.saturating_mul)
• [num::NonZero*::saturating_pow] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.saturating_pow)
• [num::NonZeroI*::abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.abs)
• [num::NonZeroI*::checked_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.checked_abs)
• [num::NonZeroI*::overflowing_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.overflowing_abs)
• [num::NonZeroI*::saturating_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.saturating_abs)
• [num::NonZeroI*::unsigned_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.unsigned_abs)
• [num::NonZeroI*::wrapping_abs] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroIsize.html#method.wrapping_abs)
• [num::NonZeroU*::checked_add] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.checked_add)
• [num::NonZeroU*::checked_next_power_of_two] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.checked_next_power_of_two)
• [num::NonZeroU*::saturating_add] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroUsize.html#method.saturating_add)
• [os::unix::process::CommandExt::process_group] (https://doc.rust-lang.org/stable/std/os/unix/process/trait.CommandExt.html#tymethod.process_group)
• [os::windows::fs::FileTypeExt::is_symlink_dir] (https://doc.rust-lang.org/stable/std/os/windows/fs/trait.FileTypeExt.html#tymethod.is_symlink_dir)
• [os::windows::fs::FileTypeExt::is_symlink_file] (https://doc.rust-lang.org/stable/std/os/windows/fs/trait.FileTypeExt.html#tymethod.is_symlink_file)

These types were previously stable in std::ffi, but are now also available in core and alloc:

• [core::ffi::CStr] (https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html)
• [core::ffi::FromBytesWithNulError] (https://doc.rust-lang.org/stable/core/ffi/struct.FromBytesWithNulError.html)
• [alloc::ffi::CString] (https://doc.rust-lang.org/stable/alloc/ffi/struct.CString.html)
• [alloc::ffi::FromVecWithNulError] (https://doc.rust-lang.org/stable/alloc/ffi/struct.FromVecWithNulError.html)
• [alloc::ffi::IntoStringError] (https://doc.rust-lang.org/stable/alloc/ffi/struct.IntoStringError.html)
• [alloc::ffi::NulError] (https://doc.rust-lang.org/stable/alloc/ffi/struct.NulError.html)

These types were previously stable in std::os::raw, but are now also available in core::ffi and std::ffi:

• [ffi::c_char] (https://doc.rust-lang.org/stable/std/ffi/type.c_char.html)
• [ffi::c_double] (https://doc.rust-lang.org/stable/std/ffi/type.c_double.html)
• [ffi::c_float] (https://doc.rust-lang.org/stable/std/ffi/type.c_float.html)
• [ffi::c_int] (https://doc.rust-lang.org/stable/std/ffi/type.c_int.html)
• [ffi::c_long] (https://doc.rust-lang.org/stable/std/ffi/type.c_long.html)
• [ffi::c_longlong] (https://doc.rust-lang.org/stable/std/ffi/type.c_longlong.html)
• [ffi::c_schar] (https://doc.rust-lang.org/stable/std/ffi/type.c_schar.html)
• [ffi::c_short] (https://doc.rust-lang.org/stable/std/ffi/type.c_short.html)
• [ffi::c_uchar] (https://doc.rust-lang.org/stable/std/ffi/type.c_uchar.html)
• [ffi::c_uint] (https://doc.rust-lang.org/stable/std/ffi/type.c_uint.html)
• [ffi::c_ulong] (https://doc.rust-lang.org/stable/std/ffi/type.c_ulong.html)
• [ffi::c_ulonglong] (https://doc.rust-lang.org/stable/std/ffi/type.c_ulonglong.html)
• [ffi::c_ushort] (https://doc.rust-lang.org/stable/std/ffi/type.c_ushort.html)

These APIs are now usable in const contexts:

• [slice::from_raw_parts] (https://doc.rust-lang.org/stable/core/slice/fn.from_raw_parts.html)

Cargo

• [Packages can now inherit settings from the workspace so that the settings can be centralized in one place.] (rust-lang/cargo#10859) See workspace.package and workspace.dependencies for more details on how to define these common settings.
• [Cargo commands can now accept multiple --target flags to build for multiple targets at once] (rust-lang/cargo#10766), and the build.target config option may now take an array of multiple targets.
• [The --jobs argument can now take a negative number to count backwards from the max CPUs.] (rust-lang/cargo#10844)
• [cargo add will now update Cargo.lock.] (rust-lang/cargo#10902)
• Added the --crate-type flag to cargo rustc to override the crate type.
• [Significantly improved the performance fetching git dependencies from GitHub when using a hash in the rev field.] (rust-lang/cargo#10079)

Misc

• [The rust-analyzer rustup component is now available on the stable channel.] (rust-lang/rust#98640)

Compatibility Notes

• The minimum required versions for all -linux-gnu targets are now at least kernel 3.2 and glibc 2.17, for targets that previously supported older versions: Increase the minimum linux-gnu versions
• [Network primitives are now implemented with the ideal Rust layout, not the C system layout] (rust-lang/rust#78802). This can cause problems when transmuting the types.
• [Add assertion that transmute_copy's U is not larger than T] (rust-lang/rust#98839)
• [A soundness bug in BTreeMap was fixed] (rust-lang/rust#99413) that allowed data it was borrowing to be dropped before the container.
• [The Drop behavior of C-like enums cast to ints has changed] (rust-lang/rust#96862). These are already discouraged by a compiler warning.
• [Relate late-bound closure lifetimes to parent fn in NLL] (rust-lang/rust#98835)
• [Errors at const-eval time are now in future incompatibility reports] (rust-lang/rust#97743)
• On the thumbv6m-none-eabi target, some incorrect asm! statements were erroneously accepted if they used the high registers (r8 to r14) as an input/output operand. [This is no longer accepted] (rust-lang/rust#99155).
• [impl Trait was accidentally accepted as the associated type value of return-position impl Trait] (rust-lang/rust#97346), without fulfilling all the trait bounds of that associated type, as long as the hidden type satisfies said bounds. This has been fixed.

Internal Changes

These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.

• Windows builds now use profile-guided optimization, providing 10-20% improvements to compiler performance: [Utilize PGO for windows x64 rustc dist builds] (rust-lang/rust#96978)
• [Stop keeping metadata in memory before writing it to disk] (rust-lang/rust#96544)
• [compiletest: strip debuginfo by default for mode=ui] (rust-lang/rust#98140)
• Many improvements to generated code for derives, including performance improvements:
  • [Don't use match-destructuring for derived ops on structs.] (rust-lang/rust#98446)
  • [Many small deriving cleanups] (rust-lang/rust#98741)
  • [More derive output improvements] (rust-lang/rust#98758)
  • Clarify deriving code
  • [Final derive output improvements] (rust-lang/rust#99046)
  • Stop injecting #[allow(unused_qualifications)] in generated derive implementations
  • Improve derive(Debug)
• Bump to clap 3
• fully move dropck to mir
• [Optimize Vec::insert for the case where index == len.] (rust-lang/rust#98755)
• [Convert rust-analyzer to an in-tree tool] (rust-lang/rust#99603)

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