resolve: Refactor `struct ExternPreludeEntry`
Avoid impossible combinations of fields and apply the first part of https://github.com/rust-lang/rust/pull/144737 (do not resolve erroneous entries repeatedly, keep them as `PendingBinding::Ready(None)` instead).
Add `Bound::copied`
Tracking Issue: https://github.com/rust-lang/rust/issues/145966
Some questions:
- [x] Should I update the documentation for `cloned` to actual used a `Clone` type instead of an integer?
- [x] I removed the `must_use` since this is a cheap copy, does that make sense?
MIR dumping is a mess. There are lots of functions and entry points,
e.g. `dump_mir`, `dump_mir_with_options`, `dump_polonius_mir`,
`dump_mir_to_writer`. Also, it's crucial that `create_dump_file` is
never called without `dump_enabled` first being checked, but there is no
mechanism for ensuring this and it's hard to tell if it is satisfied on
all paths. (`dump_enabled` is checked twice on some paths, however!)
This commit introduces `MirWriter`, which controls the MIR writing, and
encapsulates the `extra_data` closure and `options`. Two existing
functions are now methods of this type. It sets reasonable defaults,
allowing the removal of many `|_, _| Ok(())` closures.
The commit also introduces `MirDumper`, which is layered on top of
`MirWriter`, and which manages the creation of the dump files,
encapsulating pass names, disambiguators, etc. Four existing functions
are now methods of this type.
- `MirDumper::new` will only succeed if dumps are enabled, and will
return `None` otherwise, which makes it impossible to dump when you
shouldn't.
- It also sets reasonable defaults for various things like
disambiguators, which means you no longer need to specify them in many
cases. When they do need to be specified, it's now done via setter
methods.
- It avoids some repetition. E.g. `dump_nll_mir` previously specifed the
pass name `"nll"` four times and the disambiguator `&0` three times;
now it specifies them just once, to put them in the `MirDumper`.
- For Polonius, the `extra_data` closure can now be specified earlier,
which avoids having to pass some arguments through some functions.
This commit exists purely to simplify reviewing: these functions will
become methods in the next commit. This commit indents them so that the
next commit is more readable.
The dynamic dispatch cost doesn't matter for MIR dumping, which is
perf-insensitive. And it's necessary for the next commit, which will
store some `extra_data` closures in a struct.
Rollup of 4 pull requests
Successful merges:
- rust-lang/rust#144443 (Make target pointer width in target json an integer)
- rust-lang/rust#145174 (Ensure consistent drop for panicking drop in hint::select_unpredictable)
- rust-lang/rust#145592 (Fix format string grammar in docs and improve alignment error message for rust-lang/rust#144023)
- rust-lang/rust#145931 (Clarify that align_offset overaligns)
r? `@ghost`
`@rustbot` modify labels: rollup
Clarify that align_offset overaligns
The current documentation is not clear whether adding `a` to a pointer overaligns (align up) or underaligns (align down).
It should say this explicitly.
cc `@nagisa`
Fix format string grammar in docs and improve alignment error message for #144023
This PR improves error messages and documentation for format strings involving alignment and formatting traits.
Highlights:
- Clearer error messages for invalid alignment specifiers (e.g., `{0:#X>18}`), showing the expected `<`, `^`, or `>` and a working example:
println!("{0:>#18X}", value);
- Updated UI test `format-alignment-hash.rs` to reflect the improved error output.
- Documentation clarification: ensures examples correctly show how width, alignment, and traits like `x`, `X`, `#` combine.
Motivation:
Previously, using `#` with alignment and width produced confusing errors. This PR guides users on the correct syntax and provides actionable examples.
Testing:
- Built the compiler (`./x build`)
- Blessed and ran UI tests (`./x. test src/test/ui/fmt/format-alignment-hash.rs --bless`)
- Verified full test suite passes (`./x test`)
Issue: rust-lang/rust#144023
Ensure consistent drop for panicking drop in hint::select_unpredictable
There are a few alternatives to the implementation. The principal problem is that the selected value must be owned (in the sense of having a drop flag of sorts) when the unselected value is dropped, such that panic unwind goes through the drop of both. This ownership must then be passed on in return when the drop went smoothly.
The basic way of achieving this is by extracting the selected value first, at the cost of relying on the optimizer a little more for detecting the copy as constructing the return value despite having a place in the body. Unfortunately, that causes LLVM to discard the !unpredictable annotation (for some reason that is beyond my comprehension of LLVM).
<details>
<summary>Extract from the build log showing an unannotated select being used</summary>
```
2025-08-09T16:51:06.8790764Z 39: define noundef i64 `@test_int2(i1` noundef zeroext %p, i64 noundef %a, i64 noundef %b) unnamed_addr #0 personality ptr `@rust_eh_personality` {
2025-08-09T16:51:06.8791368Z check:47'0 X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
2025-08-09T16:51:06.8791700Z 40: start:
2025-08-09T16:51:06.8791858Z check:47'0 ~~~~~~~
2025-08-09T16:51:06.8792043Z 41: %ret.i = select i1 %p, i64 %a, i64 %b
2025-08-09T16:51:06.8792293Z check:47'0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2025-08-09T16:51:06.8792686Z check:47'1 ? possible intended match
2025-08-09T16:51:06.8792946Z 42: ret i64 %ret.i
2025-08-09T16:51:06.8793127Z check:47'0 ~~~~~~~~~~~~~~~~
```
</details>
So instead, this PR includes a guard to drop the selected `MaybeUnit<T>` which is active only for the section where the unselected value is dropped. That leaves the code for selecting the result intact leading to the expected ir. That complicates the 'unselection' process a little bit since we require _both_ values as a result of that intrinsic call. Since the arguments alias, this portion as well as the drop guard uses raw pointers.
Closes: rust-lang/rust#145148
Prior: rust-lang/rust#139977
Use absolute path to llvm-bolt, merge-fdata rather than PATH
This unconditionally uses the provided LLVM toolchain's BOLT. I'm not sure that makes sense, but since we don't build BOLT as part of Rust's build of LLVM today, it's probably the right option for now.
This avoids breaking the build on not being able to find the llvm-bolt executable.
Detect missing `if let` or `let-else`
During `let` binding parse error and encountering a block, detect if there is a likely missing `if` or `else`:
```
error: expected one of `.`, `;`, `?`, `else`, or an operator, found `{`
--> $DIR/missing-if-let-or-let-else.rs:14:25
|
LL | let Some(x) = foo() {
| ^ expected one of `.`, `;`, `?`, `else`, or an operator
|
help: you might have meant to use `if let`
|
LL | if let Some(x) = foo() {
| ++
help: alternatively, you might have meant to use `let else`
|
LL | let Some(x) = foo() else {
| ++++
```
Fixrust-lang/rust#107806.
Update `browser-ui-test` version to `0.21.3`
I cannot test it locally because of this bug:
```
error: couldn't generate documentation: failed to read column from disk: data consumer error: missing field `unknown number` at line 1 column 8
|
= note: failed to create or modify "build/x86_64-unknown-linux-gnu/test/rustdoc-gui/doc/search.index/entry/": failed to read column from disk: data consumer error: missing field `unknown number` at line 1 column 8
```
So I'll iterate through CI checks I guess.
r? ghost
Fix `sys::process::windows::tests::test_thread_handle` spurious failure
Instead of sleeping, wait for the process to finish so that we can be sure it's done. We use a timeout because otherwise this test can be stuck indefinitely if it fails (unfortunately std doesn't currently have a way to wait with a timeout so a manual OS API call is necessary).
I also changed the test to run `whoami` and pipe the output to null so that it doesn't clutter up the test output.
Fixesrust-lang/rust#146024
This unconditionally uses the provided LLVM toolchain's BOLT. I'm not
sure that makes sense, but since we don't build BOLT as part of Rust's
build of LLVM today, it's probably the right option for now.
This avoids breaking the build on not being able to find the llvm-bolt
executable.
With a patch applied to count the number of unifications,
and running the query `Option<T>, (T -> U) -> Option<U>`
before: performed unifyFunctionType on 17484 functions
after: performed unifyFunctionType on 3055 functions
Remove incorrect fixme on deprecation target
This does actually working suprisingly enough, applying deprecation to all methods in the impl block
r? `@jdonszelmann`
Hard-code `char::is_control`
Split off from https://github.com/rust-lang/rust/pull/145219
According to
https://www.unicode.org/policies/stability_policy.html#Property_Value, the set of codepoints in `Cc` will never change. So we can hard-code the patterns to match against instead of using a table.
This doesn't change the generated assembly, since the lookup table is small enough that[ LLVM is able to inline the whole search](https://godbolt.org/z/bG8dM37YG). But this does reduce the chance of regressions if LLVM's heuristics change in the future, and means less generated Rust code checked in to `unicode-data.rs`.
Previously, attempting to create/truncate a file without write/append access
would result in platform-specific error messages:
- Unix: "Invalid argument"
- Windows: raw OS error code 87
These error codes look like system errors, which could waste hours
of debugging for what is actually an API misuse issue.
Instead of a tuple, select the dropped value and its guard with two
separate calls to the intrinsic which makes both calls have a
pointer-valued argument that should be simpler in codegen. Use the same
condition on all (not an inverted condition) to clarify the intent of
parallel selection. This should also be a simpler value-dependency chain
if the guard is deduced unused (i.e. drop_in_place a noop for the type).
Optimize `.ilog({2,10})` to `.ilog{2,10}()`
Optimize `.ilog({2,10})` to `.ilog{2,10}()`
Inform compiler of optimizations when the base is known at compile time and there's a cheaper method available:
* `{integer}.checked_ilog(2)` -> `{integer}.checked_ilog2()`
* `{integer}.checked_ilog(10)` -> `{integer}.checked_ilog10()`
* `{integer}.ilog(2)` -> `{integer}.ilog2()`
* `{integer}.ilog(10)` -> `{integer}.ilog10()`
Implementation: `#[feature(nonpoison_condvar)]`
Tracking Issue: https://github.com/rust-lang/rust/issues/134645
This PR continues the effort made in https://github.com/rust-lang/rust/pull/144022 by adding the implementation of `nonpoison::condvar`.
Many of the changes here are similar to the changes made to implement `nonpoison::mutex`.
There are two other changes here. The first is that the `Barrier` implementation is migrated to use the `nonpoison::Condvar` instead of the `poison` variant. The second (which might be subject to some discussion) is that `WaitTimeoutResult` is moved up to `mod.rs`, as both `condvar` variants need that type (and I do not know if there is a better place to put it now).
### Related PRs
- `nonpoison_rwlock` implementation: https://github.com/rust-lang/rust/pull/144648
- `nonpoison_once` implementation: https://github.com/rust-lang/rust/pull/144653
fix(lib-std-fs): handle `usize` overflow in `read*`
I assume this is a non-breaking change, as there would be an OOM `panic` anyways. This patch ensures a fast-fail when there's not enough memory to load the file. This only changes behavior on platforms where `usize` is smaller than 64bits
Add managarm as a tier 3 target
This PR aims to introduce the `x86_64-unknown-managarm-mlibc` as a tier 3 target to Rust.
[managarm](https://github.com/managarm/managarm) is a microkernel with fully asynchronous I/O that also provides a POSIX server. Despite the differences, managarm provides good compatability with POSIX and Linux APIs. As a rule of thumb, barring OS-specific code, it should be mostly source-compatible with Linux.
We have been shipping a patched rust for over 25 releases now, and we would like to upstream our work. For a smoother process, this PR only adds the target to rustc and some documentation. `std` support will be added in a future PR.
## Addressing the tier 3 target policy
> A tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
`@no92,` `@64` and `@Dennisbonke` will be target maintainers.
> Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
> - Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
> - If possible, use only letters, numbers, dashes and underscores for the name. Periods (.) are known to cause issues in Cargo.
`x86_64-unknown-managarm-mlibc` is what we use for LLVM as well.
> Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
> - The target must not introduce license incompatibilities.
> - Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
> - The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
> - Compiling, linking, and emitting functional binaries, libraries, or other code for the target (whether hosted on the target itself or cross-compiling from another target) must not depend on proprietary (non-FOSS) libraries. Host tools built for the target itself may depend on the ordinary runtime libraries supplied by the platform and commonly used by other applications built for the target, but those libraries must not be required for code generation for the target; cross-compilation to the target must not require such libraries at all. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
> - "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are not limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
[managarm](https://github.com/managarm/managarm) is licensed as MIT. No dependencies were added.
> Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
> - This requirement does not prevent part or all of this policy from being cited in an explicit contract or work agreement (e.g. to implement or maintain support for a target). This requirement exists to ensure that a developer or team responsible for reviewing and approving a target does not face any legal threats or obligations that would prevent them from freely exercising their judgment in such approval, even if such judgment involves subjective matters or goes beyond the letter of these requirements.
Understood. None of the listed maintainers are on a Rust team.
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
Support for `std` will be provided in a future PR. Only minor changes are required, however they depend on support in the `libc` crate which will be PRed in soon.
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running binaries, or running tests (even if they do not pass), the documentation must explain how to run such binaries or tests for the target, using emulation if possible or dedicated hardware if necessary.
The steps needed to take are described in the documentation provided with this PR.
> Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via `@)` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
> - Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
Understood.
> Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
> - In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
We have no indication that anything breaks due to this PR.
> Tier 3 targets must be able to produce assembly using at least one of rustc's supported backends from any host target.
No problems here, as we target `x86_64`.
r? compiler-team
Inform compiler of optimizations when the base is known at compile time
and there's a cheaper method available:
* `{integer}.checked_ilog(2)` -> `{integer}.checked_ilog2()`
* `{integer}.checked_ilog(10)` -> `{integer}.checked_ilog10()`
* `{integer}.ilog(2)` -> `{integer}.ilog2()`
* `{integer}.ilog(10)` -> `{integer}.ilog10()`
Stuart Cook