bump bootstrap compiler to 1.90 beta
There were significantly less `cfg(bootstrap)` and `cfg(not(bootstrap))` this release. Presumably due to the fact that we change the bootstrap stage orderings to reduce the need for them and it was successful 🙏
Reimplement `print_region` in `type_name.rs`.
Broken by rust-lang/rust#144776; this is reachable after all.
Fixesrust-lang/rust#144994.
The commit also adds a lot more cases to the `type-name-basic.rs`, because it's currently very anaemic. This includes some cases where region omission does very badly; these are marked with FIXME.
r? `@fmease`
Update books
## rust-lang/book
5 commits in b2d1a0821e12a676b496d61891b8e3d374a8e832..3e9dc46aa563ca0c53ec826c41b05f10c5915925
2025-08-02 01:33:29 UTC to 2025-07-14 21:23:38 UTC
- Appendix B and Appendix D from tech review (rust-lang/book#4466)
- Chapter 21 from tech review (rust-lang/book#4464)
- Chapter 20 from tech review (rust-lang/book#4460)
- Chapter 19 from tech review (rust-lang/book#4446)
- Chapter 18 from tech review (rust-lang/book#4445)
## rust-lang/reference
12 commits in 1f45bd41fa6c17b7c048ed6bfe5f168c4311206a..1be151c051a082b542548c62cafbcb055fa8944f
2025-08-05 19:51:40 UTC to 2025-07-14 19:49:01 UTC
- Fix build output directory in README (rust-lang/reference#1950)
- Update `link_name` to use the attribute template (rust-lang/reference#1896)
- Update `no_link` to use the attribute template (rust-lang/reference#1898)
- Update `proc_macro_derive` to use the attribute template (rust-lang/reference#1888)
- Update `automatically_derived` to use the attribute template (rust-lang/reference#1884)
- Update `derive` to use the attribute template (rust-lang/reference#1883)
- Fix and clarify CR LF normalization and CR in string literals (rust-lang/reference#1944)
- glossary.md: tweak description of "dispatch" (rust-lang/reference#1938)
- add missing id, r[asm.operand-type.supported-operands.const] (rust-lang/reference#1939)
- &str and &[u8] have the same layout (rust-lang/reference#1848)
- Rename and rewrite the "question mark operator" (rust-lang/reference#1931)
- Change "allocated object" to "allocation". (rust-lang/reference#1930)
## rust-lang/rust-by-example
3 commits in e386be5f44af711854207c11fdd61bb576270b04..bd1279cdc9865bfff605e741fb76a0b2f07314a7
2025-08-04 13:41:04 UTC to 2025-08-02 15:41:59 UTC
- Improve the activity instructions in `print_display` (rust-lang/rust-by-example#1948)
- Minor fixes (whitespace, typo, i32->u32) (rust-lang/rust-by-example#1947)
- Document drawbacks of alternatives to match binding (rust-lang/rust-by-example#1946)
bootstrap: refactor mingw dist and fix gnullvm
Fixes https://github.com/rust-lang/rust/issues/144533
The first two commits are NFC and only clean up the code, paving the way for the third commit. That said, I think they are worthwhile even without that fix - reusing the same function for two different outcomes was confusing.
The third commit is the fix for https://github.com/rust-lang/rust/issues/144533, but due to the cross-compilation dance it requires a workaround to find the DLL since that logic really was meant only for Windows builders. That workaround is short-lived and will be removed as soon as gnullvm bootstraps itself.
Additional tce tests
r? `@oli-obk`
Adds known-bug tests for LLVM emissions regarding indirect operands for TCE. Also includes a test, `indexer.rs`, referring to function_table behavior described by the RFC.
Depends on rust-lang/rust#144232Closesrust-lang/rust#144293
Allow `cargo fix` to partially apply `mismatched_lifetime_syntaxes`
Workaround for https://github.com/rust-lang/rust/issues/144588#issuecomment-3128445308
Not all suggestions have to be hidden from `cargo fix`, only redundant ones. The redundant ones are already hidden from the user, so the same `tool_only` flag can be used to hide them from `cargo fix`. This way `cargo fix` will be able to correctly apply the fixes, and will apply only the fix that the compiler visibly suggests to the user.
Address libunwind.a inconsistency issues in the bootstrap program
We noticed when building rustc multiple time in a roll, some files will not be consistent across the build despite the fact that they are built from same source under the same environment. This patch addresses the inconsistency issue we found on libunwind.a, by sorting the order of the files passed to the linker.
Upgrade semicolon_in_expressions_from_macros from warn to deny
This is already warn-by-default, and a future compatibility warning (FCW) that warns in dependencies. Upgrade it to deny-by-default, as the next step towards hard error.
Per https://github.com/rust-lang/rust/issues/79813#issuecomment-3109105631
Stabilize const TypeId::of
fixesrust-lang/rust#77125
# Stabilization report for `const_type_id`
## General design
### What is the RFC for this feature and what changes have occurred to the user-facing design since the RFC was finalized?
N/A the constness was never RFCed
### What behavior are we committing to that has been controversial? Summarize the major arguments pro/con.
`const_type_id` was kept unstable because we are currently unable to stabilize the `PartialEq` impl for it (in const contexts), so we feared people would transmute the type id to an integer and compare that integer.
### Are there extensions to this feature that remain unstable? How do we know that we are not accidentally committing to those?
`TypeId::eq` is not const at this time, and will only become const once const traits are stable.
## Has a Call for Testing period been conducted? If so, what feedback was received?
This feature has been unstable for a long time, and most people just worked around it on stable by storing a pointer to `TypeId::of` and calling that at "runtime" (usually LLVM devirtualized the function pointer and inlined the call so there was no real performance difference).
A lot of people seem to be using the `const_type_id` feature gate (600 results for the feature gate on github: https://github.com/search?q=%22%23%21%5Bfeature%28const_type_id%29%5D%22&type=code)
We have had very little feedback except desire for stabilization being expressed.
## Implementation quality
Until these three PRs
* https://github.com/rust-lang/rust/pull/142789
* https://github.com/rust-lang/rust/pull/143696
* https://github.com/rust-lang/rust/pull/143736
there was no difference between the const eval feature and the runtime feature except that we prevented you from using `TypeId::of` at compile-time. These three recent PRs have hardened the internals of `TypeId`:
* it now contains an array of pointers instead of integers
* these pointers at compile-time (and in miri) contain provenance that makes them unique and prevents inspection. Both miri and CTFE will in fact error if you mess with the bits or the provenance of the pointers in any way and then try to use the `TypeId` for an equality check. This also guards against creating values of type `TypeId` by any means other than `TypeId::of`
### Summarize the major parts of the implementation and provide links into the code (or to PRs)
N/A see above
### Summarize existing test coverage of this feature
Since we are not stabilizing any operations on `TypeId` except for creating `TypeId`s, the test coverage of the runtime implementation of `TypeId` covers all the interesting use cases not in the list below
#### Hardening against transmutes
* https://github.com/rust-lang/rust/blob/master/tests/ui/consts/const_transmute_type_id.rs
* https://github.com/rust-lang/rust/blob/master/tests/ui/consts/const_transmute_type_id2.rs
* https://github.com/rust-lang/rust/blob/master/tests/ui/consts/const_transmute_type_id3.rs
* https://github.com/rust-lang/rust/blob/master/tests/ui/consts/const_transmute_type_id4.rs
* https://github.com/rust-lang/rust/blob/master/tests/ui/consts/const_transmute_type_id5.rs
#### TypeId::eq is still unstable
* https://github.com/rust-lang/rust/blob/master/tests/ui/consts/const_cmp_type_id.rs
### What outstanding bugs in the issue tracker involve this feature? Are they stabilization-blocking?
https://github.com/rust-lang/rust/issues/129014 is still unresolved, but it affects more the runtime version of `TypeId` than the compile-time.
### What FIXMEs are still in the code for that feature and why is it ok to leave them there?
none
### Summarize contributors to the feature by name for recognition and assuredness that people involved in the feature agree with stabilization
* `@eddyb`
* `@RalfJung`
### Which tools need to be adjusted to support this feature. Has this work been done?
N/A
## Type system and execution rules
### What compilation-time checks are done that are needed to prevent undefined behavior?
Already covered above. Transmuting types with private fields to expose those fields has always been library UB, but for the specific case of `TypeId` CTFE and Miri will detect it if that is done in any way other than for reconstructing the exact same `TypeId` in another location.
### Does the feature's implementation need checks to prevent UB or is it sound by default and needs opt in in places to perform the dangerous/unsafe operations? If it is not sound by default, what is the rationale?
N/A
### Can users use this feature to introduce undefined behavior, or use this feature to break the abstraction of Rust and expose the underlying assembly-level implementation? (Describe.)
N/A
### What updates are needed to the reference/specification? (link to PRs when they exist)
Nothing more than what needs to exist for `TypeId` already.
## Common interactions
### Does this feature introduce new expressions and can they produce temporaries? What are the lifetimes of those temporaries?
N/A
### What other unstable features may be exposed by this feature?
N/A
Miri: non-deterministic floating point operations in `foreign_items`
Part of [rust-lang/miri/#3555](https://github.com/rust-lang/miri/issues/3555#issue-2278914000), this pr does the `foreign_items` work.
Some things have changed since rust-lang/rust#138062 and rust-lang/rust#142514. I moved the "helpers" used for creating fixed outputs and clamping operations to their defined ranges to `math.rs`. These are now also extended to handle the floating-point operations in `foreign_items`. Tests in `miri/tests/float.rs` were changed/added.
Failing tests in `std` were extracted, run under miri with `-Zmiri-many-seeds=0..1000` and changed accordingly. Double checked with `-Zmiri-many-seeds`.
I noticed that the C standard doesn't specify the output ranges for all of its mathematical operations; it just specifies them as:
```
Returns
The sinh functions return sinh x.
```
So I used [Wolfram|Alpha](https://www.wolframalpha.com/).
lower pattern bindings in the order they're written and base drop order on primary bindings' order
To fixrust-lang/rust#142163, this PR does two things:
- Makes match arms base their drop order on the first sub-branch instead of the last sub-branch. Together with the second change, this makes bindings' drop order correspond to the relative order of when each binding first appears (i.e. the order of the "primary" bindings).
- Lowers pattern bindings in the order they're written (still treating the right-hand side of a ``@`` as coming before the binding on the left). In each sub-branch of a match arm, this is the order that would be obtained if the or-alternatives chosen in that sub-branch were inlined into the arm's pattern. This both affects drop order (making bindings in or-patterns not be dropped first) and fixes the issue in [this test](https://github.com/rust-lang/rust/blob/2a023bf80a6fbd6a06d5460a34eb247b986286ed/tests/ui/pattern/bindings-after-at/bind-by-copy-or-pat.rs) from rust-lang/rust#121716.
My approach to the second point is admittedly a bit trickier than may be necessary. To avoid passing around a counter when building `FlatPat`s, I've instead added just enough information to recover the original structure of the pattern's bindings from a `MatchTreeSubBranch`'s path through the `Candidate` tree. Some alternatives:
- We could use a counter, then sort bindings by their ordinals when making `MatchTreeSubBranch`es.
- I'd like to experiment with always merging sub-candidates and removing `test_remaining_match_pairs_after_or`; that would require lowering bindings and guards in a different way. That makes it a bigger change too, though, so I figure it might be simplest to start here.
- For a very big change, we could track which or-alternatives succeed at runtime to base drop order on the binding order in the particular alternatives matched.
This is a breaking change. It will need a crater run, language team sign-off, and likely updates to the Reference.
This will conflict with rust-lang/rust#143376 and probably also rust-lang/rust#143028, so they shouldn't be merged at the same time.
r? `@matthewjasper` or `@Nadrieril`
emit `StorageLive` and schedule `StorageDead` for `let`-`else`'s bindings after matching
This PR removes special handling of `let`-`else`, so that `StorageLive`s are emitted and `StorageDead`s are scheduled only after pattern-matching has succeeded. This means `StorageDead`s will no longer appear for all of its bindings on the `else` branch (because they're not live yet) and its drops&`StorageDead`s will happen together like they do elsewhere, rather than having all drops first, then all `StorageDead`s.
This fixesrust-lang/rust#142056, and is therefore a breaking change. I believe it'll need a crater run and a T-lang nomination/fcp thereafter. Specifically, this makes drop-checking slightly more restrictive for `let`-`else` to match the behavior of other variable binding forms. An alternative approach could be to change the relative order of drops and `StorageDead`s for other binding forms to make drop-checking more permissive, but making that consistent would be a significantly more involved change.
r? mir
cc `````@dingxiangfei2009`````
`````@rustbot````` label +T-lang +needs-crater
Tweak auto trait errors
Make suggestions to remove params and super traits verbose and make spans more accurate.
```
error[E0567]: auto traits cannot have generic parameters
--> $DIR/auto-trait-validation.rs:6:19
|
LL | auto trait Generic<T> {}
| -------^^^
| |
| auto trait cannot have generic parameters
error[E0568]: auto traits cannot have super traits or lifetime bounds
--> $DIR/auto-trait-validation.rs:8:20
|
LL | auto trait Bound : Copy {}
| ----- ^^^^
| |
| auto traits cannot have super traits or lifetime bounds
```
```
error[E0380]: auto traits cannot have associated items
--> $DIR/issue-23080.rs:5:8
|
LL | unsafe auto trait Trait {
| ----- auto traits cannot have associated items
LL | fn method(&self) {
| ^^^^^^
```
Revert "Preserve the .debug_gdb_scripts section"
https://github.com/rust-lang/rust/pull/143679 introduces a significant build time perf regression for ripgrep. Let's revert it such that we can investigate it without pressure.
Broken by #144776; this is reachable after all.
Fixes#144994.
The commit also adds a lot more cases to the `type-name-basic.rs`,
because it's currently very anaemic. This includes some cases where
region omission does very badly; these are marked with FIXME.
Print thread ID in panic message
`panic!` does not print any identifying information for threads that are
unnamed. However, in many cases, the thread ID can be determined.
This changes the panic message from something like this:
thread '<unnamed>' panicked at src/main.rs:3:5:
explicit panic
To something like this:
thread '<unnamed>' (12345) panicked at src/main.rs:3:5:
explicit panic
Stack overflow messages are updated as well.
This change applies to both named and unnamed threads. The ID printed is
the OS integer thread ID rather than the Rust thread ID, which should
also be what debuggers print.
try-job: aarch64-apple
try-job: aarch64-gnu
try-job: dist-apple-various
try-job: dist-various-*
try-job: dist-x86_64-freebsd
try-job: dist-x86_64-illumos
try-job: dist-x86_64-netbsd
try-job: dist-x86_64-solaris
try-job: test-various
try-job: x86_64-gnu
try-job: x86_64-mingw-1
try-job: x86_64-msvc-1
`panic!` does not print any identifying information for threads that are
unnamed. However, in many cases, the thread ID can be determined.
This changes the panic message from something like this:
thread '<unnamed>' panicked at src/main.rs:3:5:
explicit panic
To something like this:
thread '<unnamed>' (0xff9bf) panicked at src/main.rs:3:5:
explicit panic
Stack overflow messages are updated as well.
This change applies to both named and unnamed threads. The ID printed is
the OS integer thread ID rather than the Rust thread ID, which should
also be what debuggers print.
Rollup of 15 pull requests
Successful merges:
- rust-lang/rust#144195 (Parser: Recover from attributes applied to types and generic args)
- rust-lang/rust#144794 (Port `#[coroutine]` to the new attribute system)
- rust-lang/rust#144835 (Anonymize binders in tail call sig)
- rust-lang/rust#144861 (Stabilize `panic_payload_as_str` feature)
- rust-lang/rust#144917 (Enforce tail call type is related to body return type in borrowck)
- rust-lang/rust#144948 (we only merge candidates for trait and normalizes-to goals)
- rust-lang/rust#144956 (Gate const trait syntax)
- rust-lang/rust#144970 (rustdoc: fix caching of intra-doc links on reexports)
- rust-lang/rust#144972 (add code example showing that file_prefix treats dotfiles as the name of a file, not an extension)
- rust-lang/rust#144975 (`File::set_times`: Update documentation and example to support setting timestamps on directories)
- rust-lang/rust#144977 (Fortify generic param default checks)
- rust-lang/rust#144996 (simplifycfg: Mark as changed when start is modified in collapse goto chain)
- rust-lang/rust#144998 (mir: Do not modify NonUse in `super_projection_elem`)
- rust-lang/rust#145000 (Remove unneeded `stage` parameter when setting up stdlib Cargo)
- rust-lang/rust#145008 (Fix rustdoc scrape examples crash)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix rustdoc scrape examples crash
Fixesrust-lang/rust#144752.
The regression was introduced in https://github.com/rust-lang/rust/pull/144600. Although I don't understand why it is an issue currently, this allows to bypass the failure for now until we can figure out what's wrong as it's currently blocking new `bevy`'s release.
cc `@alice-i-cecile`
r? `@fmease`
Remove unneeded `stage` parameter when setting up stdlib Cargo
The standard library can't be built using a compiler that has a lower stage than 1 anymore, so the condition was useless (you can test that with e.g. `x doc std --stage 0`, which is broken - I aim to forbid doing that soon).
Found this while doing an unrelated cleanup.
r? `@jieyouxu`
Fortify generic param default checks
* Hard-reject instead of lint-reject type param defaults in generic assoc consts (GACs) (feature: `generic_const_items`).
* In https://github.com/rust-lang/rust/pull/113522, I explicitly handled the free const item case and forgot about the assoc const one.
* This led rustc to assume the default of emitting the deny-by-default lint `invalid_type_param_default`.
* GCIs are unstable, thus we're not bound by backward compat
* Hard-reject instead of lint-reject type param defaults in foreign items.
* We already hard-reject generic params on foreign items, so this isn't a breaking change.
* There's no reason why we need to lint-reject.
* Refactor the way we determine where generic param defaults are allowed:
* Don't default to emitting lint `invalid_type_param_defaults` for nodes that aren't explicitly handled but instead panic.
* This would've caught my GAC oversight from above much earlier via fuzzing
* Prevents us from accidentally stabilizing more invalid type param defaults in the future
* Streamline the phrasing of the diagnostic
bors