Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Create clippy lint against unexpectedly late drop for temporaries in match scrutinee expressions #94206

Merged
merged 2 commits into from
May 8, 2022

Conversation

PrestonFrom
Copy link
Contributor

@PrestonFrom PrestonFrom commented Feb 21, 2022

A new clippy lint for issue 93883 (#93883). Relies on adding a new attribute (clippy::has_significant_drop) to MutexGuard, RwLockReadGuard, and RwLockWriteGuard, which is why this PR is for the rust-lang repo and not the clippy repo.

changelog: new lint [significant_drop_in_scrutinee]

@rust-highfive
Copy link
Collaborator

Some changes occurred in src/tools/clippy.

cc @rust-lang/clippy

@rust-highfive
Copy link
Collaborator

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @Mark-Simulacrum (or someone else) soon.

Please see the contribution instructions for more information.

@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Feb 21, 2022
@oli-obk
Copy link
Contributor

oli-obk commented Feb 21, 2022

r? @oli-obk

To other reviewers: I'm fully aware that the spans, diagnostic messages, documentation and tests are not in a state yet where the lint is ready for general usage. These will get resolved before asking to move the lint out of the nursery.

@rust-log-analyzer

This comment has been minimized.

@bors
Copy link
Contributor

bors commented Feb 26, 2022

☔ The latest upstream changes (presumably #94329) made this pull request unmergeable. Please resolve the merge conflicts.

@xFrednet
Copy link
Member

Hey @PrestonFrom, Clippy creates its changelog from the PR description. Could you include a changelog entry to ensure that this new lint is caught when the changelog is written. You can just add the following line:

changelog: new lint [`significant_drop_in_scrutinee`] 

That would be a big help 🙃

@PrestonFrom
Copy link
Contributor Author

Yes, I will do that!

@rust-log-analyzer

This comment has been minimized.

@rust-log-analyzer

This comment has been minimized.

Copy link
Member

@flip1995 flip1995 left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Left some review comments, mostly about the code style.

It also seems like that something has gone wrong with the submodule updates. This PR shouldn't update any submodule.

@rust-log-analyzer

This comment has been minimized.

@PrestonFrom
Copy link
Contributor Author

Left some review comments, mostly about the code style.

It also seems like that something has gone wrong with the submodule updates. This PR shouldn't update any submodule.

Thank you for the review comments! I am not sure what happened with the submodules, but I think I have fixed it.

I'm still adding tests, but would appreciate any feed back about the matches in has_significant_drop and has_significant_drop to make sure I'm on the right track.

@rust-log-analyzer

This comment has been minimized.

Copy link
Member

@flip1995 flip1995 left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks for addressing all the comments! I left an explanation on how I think the visitor implementation could look like. Getting this right without implementing and testing it is tricky though. So it might take some experimentation from you to get the visitor right. If you get stuck and think that the visitor approach doesn't work at all, please let me know and I will try to give you some more pointers / rethink if a visitor is the right approach.

@PrestonFrom
Copy link
Contributor Author

@flip1995 @oli-obk Thank you for all your help so far! I think I have an MVP working with error message that suggests alternatives. I would appreciate another look from you both when you have time.

@rust-log-analyzer

This comment has been minimized.

@rust-log-analyzer

This comment has been minimized.

Copy link
Member

@flip1995 flip1995 left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I didn't review the tests and documentation yet.

@oli-obk oli-obk added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Mar 9, 2022
@PrestonFrom
Copy link
Contributor Author

@flip1995 Sorry for the delay -- I had a bit of trouble figuring out how to get the span/suggestion working with the match, but I think it's working. Please let me know if this approach doesn't actually work though.

@rust-log-analyzer

This comment has been minimized.

@rust-log-analyzer

This comment has been minimized.

@PrestonFrom
Copy link
Contributor Author

@flip1995 Thank you! Everything has been squashed and rebased!

This all LGTM now. Not sure why the Cargo.lock file has changes though thinking Maybe a rebase will make this unnecessary?

It looks like this was the case -- the Cargo.lock file change is gone now!

@flip1995
Copy link
Member

flip1995 commented May 7, 2022

@bors r+

Thanks! Great work!

@oli-obk
Copy link
Contributor

oli-obk commented May 7, 2022

@bors r=flip1995

Not sure why the bot ignored you outright

@oli-obk
Copy link
Contributor

oli-obk commented May 7, 2022

@bors ping

@flip1995
Copy link
Member

flip1995 commented May 7, 2022

This PR doesn't appear in the bors queue for some reason 🤔

@compiler-errors
Copy link
Member

Lemme try clicking the "synchronize" button? 🤔

@PrestonFrom
Copy link
Contributor Author

Oh no! Sorry, I’m away from my computer until tonight. Please let me know if there’s anything I can do to help.

@Mark-Simulacrum
Copy link
Member

@bors r=flip1995

@bors
Copy link
Contributor

bors commented May 7, 2022

📌 Commit d9e963f has been approved by flip1995

@bors 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 May 7, 2022
@compiler-errors
Copy link
Member

compiler-errors commented May 7, 2022

Yeah, closing and reopening it is a lot simpler than what I did. Sorry haha!

@bors
Copy link
Contributor

bors commented May 8, 2022

⌛ Testing commit d9e963f with merge 4d1076c...

@bors
Copy link
Contributor

bors commented May 8, 2022

☀️ Test successful - checks-actions
Approved by: flip1995
Pushing 4d1076c to master...

@bors bors added the merged-by-bors This PR was explicitly merged by bors. label May 8, 2022
@bors bors merged commit 4d1076c into rust-lang:master May 8, 2022
@rustbot rustbot added this to the 1.62.0 milestone May 8, 2022
@rust-timer
Copy link
Collaborator

Finished benchmarking commit (4d1076c): comparison url.

Summary:

  • Primary benchmarks: no relevant changes found
  • Secondary benchmarks: 😿 relevant regression found
Regressions 😿
(primary)
Regressions 😿
(secondary)
Improvements 🎉
(primary)
Improvements 🎉
(secondary)
All 😿 🎉
(primary)
count1 0 1 0 0 0
mean2 N/A 0.1% N/A N/A N/A
max N/A 0.1% N/A N/A N/A

If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.

@rustbot label: -perf-regression

Footnotes

  1. number of relevant changes

  2. the arithmetic mean of the percent change

@klensy
Copy link
Contributor

klensy commented May 8, 2022

Current PR description is wrong, there is no SignificantDrop marker, yes?

@PrestonFrom
Copy link
Contributor Author

@klensy Apologies! I missed updating the PR description after the initial code reviews. I just updated it. Thank you for pointing it out!

xFrednet pushed a commit to xFrednet/rust that referenced this pull request May 21, 2022
Create clippy lint against unexpectedly late drop for temporaries in match scrutinee expressions

A new clippy lint for issue 93883 (rust-lang#93883). Relies on a new trait in `marker` (called `SignificantDrop` to enable linting), which is why this PR is for the rust-lang repo and not the clippy repo.

changelog: new lint [`significant_drop_in_scrutinee`]
wip-sync pushed a commit to NetBSD/pkgsrc-wip that referenced this pull request Jul 12, 2022
Pkgsrc changes:
 * adapt patches (libc crate version bump)
 * no longer pass -I/usr/pkg/include through via gcc-wrap script.
   Attempt at fixing version skew with curl package vs. internal
   version of curl.
 * new checksums

Upstream changes:

Version 1.62.0 (2022-06-30)
==========================

Language
--------

- [Stabilize `#[derive(Default)]` on enums with a `#[default]` variant][94457]
- [Stop validating some checks in dead code after functions with
  uninhabited return types][93313]
- [Fix constants not getting dropped if part of a diverging expression][94775]
- [Support unit struct/enum variant in destructuring assignment][95380]
- [Remove mutable_borrow_reservation_conflict lint and allow the
  code pattern][96268]

Compiler
--------

- [linker: Stop using whole-archive on dependencies of dylibs][96436]
- [Make `unaligned_references` lint deny-by-default][95372]
  This lint is also a future compatibility lint, and is expected to eventually
  become a hard error.
- [Only add codegen backend to dep info if -Zbinary-dep-depinfo is used][93969]
- [Reject `#[thread_local]` attribute on non-static items][95006]
- [Add tier 3 `aarch64-pc-windows-gnullvm` and `x86_64-pc-windows-gnullvm`
  targets\*][94872]
- [Implement a lint to warn about unused macro rules][96150]
- [Promote `x86_64-unknown-none` target to Tier 2\*][95705]

\* Refer to Rust's [platform support page][platform-support-doc] for more
   information on Rust's tiered platform support.

Libraries
---------

- [Move `CStr` to libcore, and `CString` to liballoc][94079]
- [Windows: Use a pipe relay for chaining pipes][95841]
- [Replace Linux Mutex and Condvar with futex based ones.][95035]
- [Replace RwLock by a futex based one on Linux][95801]
- [std: directly use pthread in UNIX parker implementation][96393]

Stabilized APIs
---------------

- [`bool::then_some`]
- [`f32::total_cmp`]
- [`f64::total_cmp`]
- [`Stdin::lines`]
- [`windows::CommandExt::raw_arg`]
- [`impl<T: Default> Default for AssertUnwindSafe<T>`]
- [`From<Rc<str>> for Rc<[u8]>`][rc-u8-from-str]
- [`From<Arc<str>> for Arc<[u8]>`][arc-u8-from-str]
- [`FusedIterator for EncodeWide`]
- [RDM intrinsics on aarch64][stdarch/1285]

Clippy
------

- [Create clippy lint against unexpectedly late drop for temporaries
  in match scrutinee expressions][94206]

Cargo
-----

- Added the `cargo add` command for adding dependencies to `Cargo.toml` from
  the command-line.
  [docs](https://doc.rust-lang.org/nightly/cargo/commands/cargo-add.html)
- Package ID specs now support `name@version` syntax in addition to the
  previous `name:version` to align with the behavior in `cargo add` and other
  tools. `cargo install` and `cargo yank` also now support this syntax so the
  version does not need to passed as a separate flag.
- The `git` and `registry` directories in Cargo's home directory (usually
  `~/.cargo`) are now marked as cache directories so that they are not
  included in backups or content indexing (on Windows).
- Added automatic `@` argfile support, which will use "response files" if the
  command-line to `rustc` exceeds the operating system's limit.

Compatibility Notes
-------------------

- `cargo test` now passes `--target` to `rustdoc` if the specified target is
  the same as the host target.
  [#10594](rust-lang/cargo#10594)
- [rustdoc: Remove .woff font files][96279]
- [Enforce Copy bounds for repeat elements while considering lifetimes][95819]

Internal Changes
----------------

- [Unify ReentrantMutex implementations across all platforms][96042]

These changes provide no direct user facing benefits, but represent
significant improvements to the internals and overall performance
of rustc and related tools.

[93313]: rust-lang/rust#93313
[93969]: rust-lang/rust#93969
[94079]: rust-lang/rust#94079
[94206]: rust-lang/rust#94206
[94457]: rust-lang/rust#94457
[94775]: rust-lang/rust#94775
[94872]: rust-lang/rust#94872
[95006]: rust-lang/rust#95006
[95035]: rust-lang/rust#95035
[95372]: rust-lang/rust#95372
[95380]: rust-lang/rust#95380
[95431]: rust-lang/rust#95431
[95705]: rust-lang/rust#95705
[95801]: rust-lang/rust#95801
[95819]: rust-lang/rust#95819
[95841]: rust-lang/rust#95841
[96042]: rust-lang/rust#96042
[96150]: rust-lang/rust#96150
[96268]: rust-lang/rust#96268
[96279]: rust-lang/rust#96279
[96393]: rust-lang/rust#96393
[96436]: rust-lang/rust#96436
[96557]: rust-lang/rust#96557

[`bool::then_some`]: https://doc.rust-lang.org/stable/std/primitive.bool.html#method.then_some
[`f32::total_cmp`]: https://doc.rust-lang.org/stable/std/primitive.f32.html#method.total_cmp
[`f64::total_cmp`]: https://doc.rust-lang.org/stable/std/primitive.f64.html#method.total_cmp
[`Stdin::lines`]: https://doc.rust-lang.org/stable/std/io/struct.Stdin.html#method.lines
[`impl<T: Default> Default for AssertUnwindSafe<T>`]: https://doc.rust-lang.org/stable/std/panic/struct.AssertUnwindSafe.html#impl-Default
[rc-u8-from-str]: https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#impl-From%3CRc%3Cstr%3E%3E
[arc-u8-from-str]: https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#impl-From%3CArc%3Cstr%3E%3E
[stdarch/1285]: rust-lang/stdarch#1285
[`windows::CommandExt::raw_arg`]: https://doc.rust-lang.org/stable/std/os/windows/process/trait.CommandExt.html#tymethod.raw_arg
[`FusedIterator for EncodeWide`]: https://doc.rust-lang.org/stable/std/os/windows/ffi/struct.EncodeWide.html#impl-FusedIterator
netbsd-srcmastr pushed a commit to NetBSD/pkgsrc that referenced this pull request Aug 31, 2022
Pkgsrc changes:

 * Bump required GCC to 7 (same as LLVM) to avoid ABI issues
   Fixes native i386 and powerpc 8.x build w/pkgsrc LLVM 14
 * Bump available bootstraps to 1.61.0.
 * Also unlimit stacksize
 * Sync patches over from wip/rust
 * Adjust line number in patches which had non-zero offsets.
 * no longer pass -I/usr/pkg/include through via gcc-wrap script
   when building natively.  Attempt at fixing version skew with curl
   package vs. internal version of curl (may not work...)
 * The NetBSD bootstraps now use .xz compression.
 * Use mk/atomic64.mk.  Still have conditional for libatomic-links.
 * Default to using the internal LLVM when cross-building.


Upstream changes:

Version 1.62.1 (2022-07-19)
==========================

Rust 1.62.1 addresses a few recent regressions in the compiler and standard
library, and also mitigates a CPU vulnerability on Intel SGX.

* [The compiler fixed unsound function coercions involving `impl
  Trait` return types.][98608]
* [The compiler fixed an incremental compilation bug with `async
  fn` lifetimes.][98890]
* [Windows added a fallback for overlapped I/O in synchronous reads
  and writes.][98950]
* [The `x86_64-fortanix-unknown-sgx` target added a mitigation for the
  MMIO stale data vulnerability][98126], advisory [INTEL-SA-00615].

[98608]: rust-lang/rust#98608
[98890]: rust-lang/rust#98890
[98950]: rust-lang/rust#98950
[98126]: rust-lang/rust#98126
[INTEL-SA-00615]: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00615.html


Version 1.62.0 (2022-06-30)
==========================

Language
--------

- [Stabilize `#[derive(Default)]` on enums with a `#[default]` variant][94457]
- [Stop validating some checks in dead code after functions with
  uninhabited return types][93313]
- [Fix constants not getting dropped if part of a diverging expression][94775]
- [Support unit struct/enum variant in destructuring assignment][95380]
- [Remove mutable_borrow_reservation_conflict lint and allow the
  code pattern][96268]

Compiler
--------

- [linker: Stop using whole-archive on dependencies of dylibs][96436]
- [Make `unaligned_references` lint deny-by-default][95372]
  This lint is also a future compatibility lint, and is expected to eventually
  become a hard error.
- [Only add codegen backend to dep info if -Zbinary-dep-depinfo is used][93969]
- [Reject `#[thread_local]` attribute on non-static items][95006]
- [Add tier 3 `aarch64-pc-windows-gnullvm` and `x86_64-pc-windows-gnullvm`
  targets\*][94872]
- [Implement a lint to warn about unused macro rules][96150]
- [Promote `x86_64-unknown-none` target to Tier 2\*][95705]

\* Refer to Rust's [platform support page][platform-support-doc] for more
   information on Rust's tiered platform support.

Libraries
---------

- [Move `CStr` to libcore, and `CString` to liballoc][94079]
- [Windows: Use a pipe relay for chaining pipes][95841]
- [Replace Linux Mutex and Condvar with futex based ones.][95035]
- [Replace RwLock by a futex based one on Linux][95801]
- [std: directly use pthread in UNIX parker implementation][96393]

Stabilized APIs
---------------

- [`bool::then_some`]
- [`f32::total_cmp`]
- [`f64::total_cmp`]
- [`Stdin::lines`]
- [`windows::CommandExt::raw_arg`]
- [`impl<T: Default> Default for AssertUnwindSafe<T>`]
- [`From<Rc<str>> for Rc<[u8]>`][rc-u8-from-str]
- [`From<Arc<str>> for Arc<[u8]>`][arc-u8-from-str]
- [`FusedIterator for EncodeWide`]
- [RDM intrinsics on aarch64][stdarch/1285]

Clippy
------

- [Create clippy lint against unexpectedly late drop for temporaries
  in match scrutinee expressions][94206]

Cargo
-----

- Added the `cargo add` command for adding dependencies to `Cargo.toml` from
  the command-line.
  [docs](https://doc.rust-lang.org/nightly/cargo/commands/cargo-add.html)
- Package ID specs now support `name@version` syntax in addition to the
  previous `name:version` to align with the behavior in `cargo add` and other
  tools. `cargo install` and `cargo yank` also now support this syntax so the
  version does not need to passed as a separate flag.
- The `git` and `registry` directories in Cargo's home directory (usually
  `~/.cargo`) are now marked as cache directories so that they are not
  included in backups or content indexing (on Windows).
- Added automatic `@` argfile support, which will use "response files" if the
  command-line to `rustc` exceeds the operating system's limit.

Compatibility Notes
-------------------

- `cargo test` now passes `--target` to `rustdoc` if the specified target is
  the same as the host target.
  [#10594](rust-lang/cargo#10594)
- [rustdoc: Remove .woff font files][96279]
- [Enforce Copy bounds for repeat elements while considering lifetimes][95819]

Internal Changes
----------------

- [Unify ReentrantMutex implementations across all platforms][96042]

These changes provide no direct user facing benefits, but represent
significant improvements to the internals and overall performance
of rustc and related tools.

[93313]: rust-lang/rust#93313
[93969]: rust-lang/rust#93969
[94079]: rust-lang/rust#94079
[94206]: rust-lang/rust#94206
[94457]: rust-lang/rust#94457
[94775]: rust-lang/rust#94775
[94872]: rust-lang/rust#94872
[95006]: rust-lang/rust#95006
[95035]: rust-lang/rust#95035
[95372]: rust-lang/rust#95372
[95380]: rust-lang/rust#95380
[95431]: rust-lang/rust#95431
[95705]: rust-lang/rust#95705
[95801]: rust-lang/rust#95801
[95819]: rust-lang/rust#95819
[95841]: rust-lang/rust#95841
[96042]: rust-lang/rust#96042
[96150]: rust-lang/rust#96150
[96268]: rust-lang/rust#96268
[96279]: rust-lang/rust#96279
[96393]: rust-lang/rust#96393
[96436]: rust-lang/rust#96436
[96557]: rust-lang/rust#96557

[`bool::then_some`]: https://doc.rust-lang.org/stable/std/primitive.bool.html#method.then_some
[`f32::total_cmp`]: https://doc.rust-lang.org/stable/std/primitive.f32.html#method.total_cmp
[`f64::total_cmp`]: https://doc.rust-lang.org/stable/std/primitive.f64.html#method.total_cmp
[`Stdin::lines`]: https://doc.rust-lang.org/stable/std/io/struct.Stdin.html#method.lines
[`impl<T: Default> Default for AssertUnwindSafe<T>`]: https://doc.rust-lang.org/stable/std/panic/struct.AssertUnwindSafe.html#impl-Default
[rc-u8-from-str]: https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#impl-From%3CRc%3Cstr%3E%3E
[arc-u8-from-str]: https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#impl-From%3CArc%3Cstr%3E%3E
[stdarch/1285]: rust-lang/stdarch#1285
[`windows::CommandExt::raw_arg`]: https://doc.rust-lang.org/stable/std/os/windows/process/trait.CommandExt.html#tymethod.raw_arg
[`FusedIterator for EncodeWide`]: https://doc.rust-lang.org/stable/std/os/windows/ffi/struct.EncodeWide.html#impl-FusedIterator


Version 1.61.0 (2022-05-19)
==========================

Language
--------

- [`const fn` signatures can now include generic trait bounds][93827]
- [`const fn` signatures can now use `impl Trait` in argument and return
  position][93827]
- [Function pointers can now be created, cast, and passed around in a
  `const fn`][93827]
- [Recursive calls can now set the value of a function's opaque
  `impl Trait` return type][94081]

Compiler
--------

- [Linking modifier syntax in `#[link]` attributes and on the command
  line, as well as the `whole-archive` modifier specifically, are now
  supported][93901]
- [The `char` type is now described as UTF-32 in debuginfo][89887]
- The [`#[target_feature]`][target_feature] attribute
  [can now be used with aarch64 features][90621]
- X86 [`#[target_feature = "adx"]` is now stable][93745]

Libraries
---------

- [`ManuallyDrop<T>` is now documented to have the same layout as `T`][88375]
- [`#[ignore = "#"]` messages are printed when running tests][92714]
- [Consistently show absent stdio handles on Windows as NULL handles][93263]
- [Make `std::io::stdio::lock()` return `'static` handles.][93965]
  Previously, the creation of locked handles to stdin/stdout/stderr would
  borrow the handles being locked, which prevented writing
  `let out = std::io::stdout().lock();` because `out` would outlive
  the return value of `stdout()`.
  Such code now works, eliminating a common pitfall that affected many
  Rust users.
- [`Vec::from_raw_parts` is now less restrictive about its inputs][95016]
- [`std::thread::available_parallelism` now takes cgroup quotas into
  account.][92697] Since `available_parallelism` is often used to create a
  thread pool for parallel computation, which may be CPU-bound for
  performance, `available_parallelism` will return a value consistent with
  the ability to use that many threads continuously, if possible.
  For instance, in a container with 8 virtual CPUs but quotas only allowing
  for 50% usage, `available_parallelism` will return 4.

Stabilized APIs
---------------

- [`Pin::static_mut`]
- [`Pin::static_ref`]
- [`Vec::retain_mut`]
- [`VecDeque::retain_mut`]
- [`Write` for `Cursor<[u8; N]>`][cursor-write-array]
- [`std::os::unix::net::SocketAddr::from_pathname`]
- [`std::process::ExitCode`] and [`std::process::Termination`].
  The stabilization of these two API s now makes it possible for
  programs to return errors from `main` with custom exit codes.
- [`std::thread::JoinHandle::is_finished`]

These APIs are now usable in const contexts:

- [`<*const T>::offset` and `<*mut T>::offset`][ptr-offset]
- [`<*const T>::wrapping_offset` and `<*mut T>::wrapping_offset`]
  [ptr-wrapping_offset]
- [`<*const T>::add` and `<*mut T>::add`][ptr-add]
- [`<*const T>::sub` and `<*mut T>::sub`][ptr-sub]
- [`<*const T>::wrapping_add` and `<*mut T>::wrapping_add`][ptr-wrapping_add]
- [`<*const T>::wrapping_sub` and `<*mut T>::wrapping_sub`][ptr-wrapping_sub]
- [`<[T]>::as_mut_ptr`][slice-as_mut_ptr]
- [`<[T]>::as_ptr_range`][slice-as_ptr_range]
- [`<[T]>::as_mut_ptr_range`][slice-as_mut_ptr_range]

Cargo
-----

No feature changes, but see compatibility notes.

Compatibility Notes
-------------------

- Previously native static libraries were linked as `whole-archive` in
  some cases, but now rustc tries not to use `whole-archive` unless
  explicitly requested. This [change][93901] may result in linking errors
  in some cases. To fix such errors, native libraries linked from the
  command line, build scripts, or [`#[link]` attributes][link-attr] need to
  - (more common) either be reordered to respect dependencies between them
    (if `a` depends on `b` then `a` should go first and `b` second)
  - (less common) or be updated to use the [`+whole-archive`] modifier.
- [Catching a second unwind from FFI code while cleaning up from a Rust
  panic now causes the process to abort][92911]
- [Proc macros no longer see `ident` matchers wrapped in groups][92472]
- [The number of `#` in `r#` raw string literals is now required to be
  less than 256][95251]
- [When checking that a dyn type satisfies a trait bound, supertrait
  bounds are now enforced][92285]
- [`cargo vendor` now only accepts one value for each `--sync` flag]
  [cargo/10448]
- [`cfg` predicates in `all()` and `any()` are always evaluated to detect
  errors, instead of short-circuiting.][94295] The compatibility
  considerations here arise in nightly-only code that used the
  short-circuiting behavior of `all` to write something like
  `cfg(all(feature = "nightly", syntax-requiring-nightly))`, which
  will now fail to compile. Instead, use either `cfg_attr(feature
  = "nightly", ...)` or nested uses of `cfg`.
- [bootstrap: static-libstdcpp is now enabled by default, and can
  now be disabled when llvm-tools is enabled][94832]

Internal Changes
----------------

These changes provide no direct user facing benefits, but represent
significant improvements to the internals and overall performance
of rustc and related tools.

- [debuginfo: Refactor debuginfo generation for types][94261]
- [Remove the everybody loops pass][93913]

[88375]: rust-lang/rust#88375
[89887]: rust-lang/rust#89887
[90621]: rust-lang/rust#90621
[92285]: rust-lang/rust#92285
[92472]: rust-lang/rust#92472
[92697]: rust-lang/rust#92697
[92714]: rust-lang/rust#92714
[92911]: rust-lang/rust#92911
[93263]: rust-lang/rust#93263
[93745]: rust-lang/rust#93745
[93827]: rust-lang/rust#93827
[93901]: rust-lang/rust#93901
[93913]: rust-lang/rust#93913
[93965]: rust-lang/rust#93965
[94081]: rust-lang/rust#94081
[94261]: rust-lang/rust#94261
[94295]: rust-lang/rust#94295
[94832]: rust-lang/rust#94832
[95016]: rust-lang/rust#95016
[95251]: rust-lang/rust#95251
[`+whole-archive`]: https://doc.rust-lang.org/stable/rustc/command-line-arguments.html#linking-modifiers-whole-archive
[`Pin::static_mut`]: https://doc.rust-lang.org/stable/std/pin/struct.Pin.html#method.static_mut
[`Pin::static_ref`]: https://doc.rust-lang.org/stable/std/pin/struct.Pin.html#method.static_ref
[`Vec::retain_mut`]: https://doc.rust-lang.org/stable/std/vec/struct.Vec.html#method.retain_mut
[`VecDeque::retain_mut`]: https://doc.rust-lang.org/stable/std/collections/struct.VecDeque.html#method.retain_mut
[`std::os::unix::net::SocketAddr::from_pathname`]: https://doc.rust-lang.org/stable/std/os/unix/net/struct.SocketAddr.html#method.from_pathname
[`std::process::ExitCode`]: https://doc.rust-lang.org/stable/std/process/struct.ExitCode.html
[`std::process::Termination`]: https://doc.rust-lang.org/stable/std/process/trait.Termination.html
[`std::thread::JoinHandle::is_finished`]: https://doc.rust-lang.org/stable/std/thread/struct.JoinHandle.html#method.is_finished
[cargo/10448]: rust-lang/cargo#10448
[cursor-write-array]: https://doc.rust-lang.org/stable/std/io/struct.Cursor.html#impl-Write-4
[link-attr]: https://doc.rust-lang.org/stable/reference/items/external-blocks.html#the-link-attribute
[ptr-add]: https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.add
[ptr-offset]: https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.offset
[ptr-sub]: https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.sub
[ptr-wrapping_add]: https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.wrapping_add
[ptr-wrapping_offset]: https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.wrapping_offset
[ptr-wrapping_sub]: https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.wrapping_sub
[slice-as_mut_ptr]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.as_mut_ptr
[slice-as_mut_ptr_range]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.as_mut_ptr_range
[slice-as_ptr_range]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.as_ptr_range
[target_feature]: https://doc.rust-lang.org/reference/attributes/codegen.html#the-target_feature-attribute
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
merged-by-bors This PR was explicitly merged by bors. S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. T-libs Relevant to the library team, which will review and decide on the PR/issue.
Projects
None yet
Development

Successfully merging this pull request may close these issues.