Rollup of 8 pull requests
Successful merges:
- #137653 (Deprecate the unstable `concat_idents!`)
- #138957 (Update the index of Option to make the summary more comprehensive)
- #140006 (ensure compiler existance of tools on the dist step)
- #140143 (Move `sys::pal::os::Env` into `sys::env`)
- #140202 (Make #![feature(let_chains)] bootstrap conditional in compiler/)
- #140236 (norm nested aliases before evaluating the parent goal)
- #140257 (Some drive-by housecleaning in `rustc_borrowck`)
- #140278 (Don't use item name to look up associated item from trait item)
r? `@ghost`
`@rustbot` modify labels: rollup
Revert compiletest new-executor, to re-land without download-rustc
Revert <https://github.com/rust-lang/rust/pull/139998> because the original merge triggered download-rustc, which messes with test metrics and prevents us from properly comparing them before/after the change.
The plan is to re-land this PR as-is, combined with a trivial compiler change to avoid download-rustc and get proper test metrics for comparison.
This reverts commit be181dd75c, reversing changes made to 645d0ad2a4.
r? ghost
Deprecate the unstable `concat_idents!`
`concat_idents` has been around unstably for a long time, but there is now a better (but still unstable) way to join identifiers using `${concat(...)}` syntax with `macro_metavar_expr_concat`. This resolves a lot of the problems with `concat_idents` and is on a better track toward stabilization, so there is no need to keep both versions around. `concat_idents!` still has a lot of use in the ecosystem so deprecate it before removing, as discussed in [1].
Link: https://github.com/rust-lang/rust/issues/124225
[1]: https://rust-lang.zulipchat.com/#narrow/channel/219381-t-libs/topic/Removing.20.60concat_idents.60
Stabilize flags for doctest cross compilation
This makes the following changes in preparation for supporting doctest cross-compiling in cargo:
- Renames `--runtool` and `--runtool-arg` to `--test-runtool` and `--test-runtool-arg` to maintain consistency with other `--test-*` arguments.
- Stabilizes the `--test-runtool` and `--test-runtool-arg`. These are needed in order to support cargo's `target.runner` option which specifies a runner to execute a cross-compiled doctest (for example, qemu).
- Stabilizes the `--enable-per-target-ignores` flag by removing it and making it unconditionally enabled. This makes it possible to disable a doctest on a per-target basis, which I think will be helpful for rolling out this feature.
These changes were suggested in https://rust-lang.zulipchat.com/#narrow/channel/266220-t-rustdoc/topic/stabilizing.20doctest.20xcompile/near/409281127
The intent is to stabilize the doctest-xcompile feature in cargo. This will help ensure that for projects that do cross-compile testing that their doctests are also covered. Currently there is a somewhat surprising behavior that they are ignored.
Closes https://github.com/rust-lang/rust/issues/64245
try-job: x86_64-msvc-1
`concat_idents` has been around unstably for a long time, but there is
now a better (but still unstable) way to join identifiers using
`${concat(...)}` syntax with `macro_metavar_expr_concat`. This resolves
a lot of the problems with `concat_idents` and is on a better track
toward stabilization, so there is no need to keep both versions around.
`concat_idents!` still has a lot of use in the ecosystem so deprecate it
before removing, as discussed in [1].
Link: https://github.com/rust-lang/rust/issues/124225
[1]: https://rust-lang.zulipchat.com/#narrow/channel/219381-t-libs/topic/Removing.20.60concat_idents.60
Remove git repository from git config
It is no longer needed after https://github.com/rust-lang/rust/pull/138591. We could even remove the `nightly_branch` field, but it still has one usage.
r? ``@jieyouxu``
Suggest {to,from}_ne_bytes for transmutations between arrays and integers, etc
implements #136067
Rust has helper methods for many kinds of safe transmutes, for example integer<->bytes. This is a lint against using transmute for these cases.
```rs
fn bytes_at_home(x: [u8; 4]) -> u32 {
transmute(x)
}
// other examples
transmute::<[u8; 2], u16>();
transmute::<[u8; 8], f64>();
transmute::<u32, [u8; 4]>();
transmute::<char, u32>();
transmute::<u32, char>();
```
It would be handy to suggest `u32::from_ne_bytes(x)`.
This is implemented for `[u8; _]` -> `{float int}`
This also implements the cases:
`fXX` <-> `uXX` = `{from_bits, to_bits}`
`uXX` -> `iXX` via `cast_unsigned` and `cast_signed`
{`char` -> `u32`, `bool` -> `n8`} via `from`
`u32` -> `char` via `from_u32_unchecked` (note: notes `from_u32().unwrap()`) (contested)
`u8` -> `bool` via `==` (debatable)
---
try-job: aarch64-gnu
try-job: test-various
minicore: Have `//@ add-core-stubs` also imply `-Cforce-unwind-tables=yes`
To preserve CFI directives in assembly tests, as `//@ add-core-stubs` already imply `-C panic=abort`.
This is a blocker for https://github.com/rust-lang/rust/pull/140037#issuecomment-2816665358.
cc ```@RalfJung```
r? ```@bjorn3```
mitigate MSVC alignment issue on x86-32
This implements mitigation for https://github.com/rust-lang/rust/issues/112480 by stopping to emit `align` attributes on loads and function arguments when building for a win32 MSVC target. MSVC is known to not properly align `u64` and similar types, and claiming to LLVM that everything is properly aligned increases the chance that this will cause problems.
Of course, the misalignment is still a bug, but we can't fix that bug, only MSVC can.
Also add an errata note to the platform support page warning users about this known problem.
try-job: `i686-msvc*`
`deref_patterns`: support string and byte string literals in explicit `deref!("...")` patterns
When `deref_patterns` is enabled, this allows string literal patterns to be used where `str` is expected and byte string literal patterns to be used where `[u8]` or `[u8; N]` is expected. This lets them be used in explicit `deref!("...")` patterns to match on `String`, `Box<str>`, `Vec<u8>`, `Box<[u8;N]>`, etc. (as well as to match on slices and arrays obtained through other means). Implementation-wise, this follows up on #138992: similar to how byte string literals matching on `&[u8]` is implemented, this changes the type of the patterns as determined by HIR typeck, which informs const-to-pat on how to translate them to THIR (though strings needed a bit of extra work since we need references to call `<str as PartialEq>::eq` in the MIR lowering for string equality tests).
This PR does not add support for implicit deref pattern syntax (e.g. `"..."` matching on `String`, as `string_deref_patterns` allows). I have that implemented locally, but I'm saving it for a follow-up PR[^1].
This also does not add support for using named or associated constants of type `&str` where `str` is expected (nor likewise with named byte string constants). It'd be possible to add that if there's an appetite for it, but I figure it's simplest to start with literals.
This is gated by the `deref_patterns` feature since it's motivated by deref patterns. That said, its impact reaches outside of deref patterns; it may warrant a separate experiment and feature gate, particularly factoring in the follow-up[^1]. Even without deref patterns, I think there's probably motivation for these changes.
The update to the unstable book added by this will conflict with #140022, so they shouldn't be merged at the same time.
Tracking issue for deref patterns: #87121
r? ``@oli-obk``
cc ``@Nadrieril``
[^1]: The piece missing from this PR to support implicit deref pattern syntax is to allow string literal patterns to implicitly dereference their scrutinees before matching (see #44849). As a consequence, it also makes examples like the one in that issue work (though it's still gated by `deref_patterns`). I can provide more information on how I've implemented it or open a draft if it'd help in reviewing this PR.
Revert <https://github.com/rust-lang/rust/pull/139998> because the original
merge triggered download-rustc, which messes with test metrics and prevents us
from properly comparing them before/after the change.
The plan is to re-land this PR as-is, combined with a trivial compiler change
to avoid download-rustc and get proper test metrics for comparison.
This reverts commit be181dd75c, reversing
changes made to 645d0ad2a4.
I found these by grepping for `&[a-z_\.]*\.clone()`, i.e. expressions
like `&a.b.clone()`, which are sometimes unnecessary clones, and also
looking at clones nearby to cases like that.
Clippy subtree update
r? `@Manishearth`
Cargo.lock update due to the Clippy version bump and because Clippy moved from rinja (unmaintained) to askama.
Last sync was skipped due to the askama issue and me not getting to fixing this in time.
compiletest: Use the new non-libtest executor by default
The new executor was implemented in #139660, but required a manual opt-in. This PR activates the new executor by default, but leaves the old libtest-based executor in place (temporarily) to make reverting easier if something unexpectedly goes horribly wrong.
Currently the new executor can be explicitly disabled by passing the `-N` flag to compiletest (e.g. `./x test ui -- -N`), but eventually that flag will be removed, alongside the removal of the libtest dependency. The flag is mostly there to make manual comparative testing easier if something does go wrong.
As before, there *should* be no user-visible difference between the old executor and the new executor.
---
I didn't get much of a response to my [call for testing thread on Zulip](https://rust-lang.zulipchat.com/#narrow/channel/122651-general/topic/Call.20for.20testing.3A.20New.20test.20executor.20for.20compiletest/with/512452105), and the reports I did get (along with my own usage) indicate that there aren't any problems. So I think it's reasonable to move forward with making this the default, in the hopes of being able to remove the libtest dependency relatively soon.
When the libtest dependency is removed, it should be reasonable to build compiletest against pre-built stage0 std by default, even after the stage0 redesign. (Though we should probably have at least one CI job using in-tree stage1 std instead, to guard against the possibility of the `#![feature(internal_output_capture)]` API actually changing.)
Refactor git change detection in bootstrap
While working on https://github.com/rust-lang/rust/pull/138395, I finally found the courage to delve into the insides of git path change detection in bootstrap, which is used (amongst other things) to detect if we should rebuilt od download `[llvm|rustc|gcc]`. I found it a bit hard to understand, and given that this code was historically quite fragile, I thought that it would be better to rebuild it from scratch.
The previous approach had a bunch of limitations:
- It separated the computation of "are there local changes?" and "what upstream SHA should we use?" even though these two things are intertwined.
- It used hacks to work around what happens on CI.
- It had special cases for CI scattered throughout the codebase, rather than centralized in one place.
- It wasn't documented enough and didn't have tests for the git behavior.
The current approach should hopefully resolve all of that. I implemented a single entrypoint called `check_path_modifications` (naming bikeshed pending, half of the time I spend on this PR was thinking about names, as it's quite tricky here..) that explicitly receives a mode of operation (in CI or outside CI), and accordingly figures out that upstream SHA that we should use for downloading artifacts and it also figures out if there are any local changes. Users of this function can then use this unified output to implement `download-ci-X` and other functionality. Notably, this change detection no longer uses `git merge-base`, which makes it easier to use and doesn't require setting up remotes.
I also added a bunch of integration tests that literally spawn a git repository on disk and then check that the function can deal with various situations (PR CI, auto/try CI, local builds).
After I built this inner layer, I used it for downloading GCC, LLVM and rustc. The latter two (and especially rustc) were using the `last_modified_commit` function before, but in all cases but one this function was actually only used to check if there are any local changes, which was IMO confusing. The LLVM handling would deserve a bit of refactoring, but that's a larger change that can be done as a follow-up.
I hope that the implementation is now clear and easy to understand, so that in combination with the tests we can have more confidence that it does what we want. I tried to include a lot of documentation in the code, so I won't be repeating the actual implementation details here, if there are any questions, I'll add the answers to the documentation too :)
The new approach explicitly supports three scenarios:
- Running on PR CI, where we have one upstream bors parent commit and one PR merge commit made by GitHub.
- Running on try/auto CI, where we have one upstream bors parent commit and one PR merge commit made by bors.
- Running locally, where we assume that we have at least one upstream bors parent commit in our git history.
I removed the handling of upstreams on CI, as I think that it shouldn't be needed and I considered it to be a hack. However, it's possible that there are other use-cases that I haven't considered, so I want to ask around if people have other situations than the three use-cases described above. If there are other such use-cases, I would like to include them in the new centralized implementation and add them to the git test suite, rather than going back to the old ways :)
In particular, the code before relied on `git merge-base`, but I don't see why we can't just lookup the most recent bors commit and assume that is a merge commit that is also upstream? I might be running into Chesterton's Fence here :)
CC `@pietroalbini` To make sure that this won't break downstream users of Rust's CI.
Best reviewed commit by commit.
Companion PRs:
- For testing beta: https://github.com/rust-lang/rust/pull/138597
r? `@onur-ozkan`
Fixes: https://github.com/rust-lang/rust/issues/101907
try-job: x86_64-gnu-aux
try-job: aarch64-gnu
try-job: dist-x86_64-apple
Currently the new executor can be explicitly disabled by passing the `-N` flag
to compiletest (e.g. `./x test ui -- -N`), but eventually that flag will be
removed, alongside the removal of the libtest dependency.
Update books
## rust-lang/nomicon
1 commits in 0c10c30cc54736c5c194ce98c50e2de84eeb6e79..c76a20f0d987145dcedf05c5c073ce8d91f2e82a
2025-04-15 20:54:57 UTC to 2025-04-15 20:54:57 UTC
- Say that dereferencing a pointer to a ZST is no longer undefined (rust-lang/nomicon#467)
## rust-lang/reference
7 commits in 3340922df189bddcbaad17dc3927d51a76bcd5ed..3bf3402aea982b876eb56c87da17b0685c6461d5
2025-04-18 13:44:45 UTC to 2025-04-17 17:27:01 UTC
- Use `cfg(false)` instead of `cfg(FALSE)` (rust-lang/reference#1763)
- Add `cfg(true)` and `cfg(false)` to conditional compilation (RFC 3695) (rust-lang/reference#1762)
- Refactor rendering with `RenderCtx` (rust-lang/reference#1796)
- attributes/codegen: update aarch64 features (rust-lang/reference#1791)
- Simplify GenericParams grammar (rust-lang/reference#1795)
- Add rule identifiers for the ABI chapter (rust-lang/reference#1793)
- Remove broken footnote links from grammar summary (rust-lang/reference#1794)
Use correct annotation for CSS pseudo elements
The list of CSS pseudo elements is pretty short so it was easy to go through. Even though the `:` is accepted, it's incorrect.
For a description of CSS pseudo elements: https://developer.mozilla.org/en-US/docs/Web/CSS/Pseudo-elements
r? ``@notriddle``
Remove `token::{Open,Close}Delim`
By replacing them with `{Open,Close}{Param,Brace,Bracket,Invisible}`.
PR #137902 made `ast::TokenKind` more like `lexer::TokenKind` by
replacing the compound `BinOp{,Eq}(BinOpToken)` variants with fieldless
variants `Plus`, `Minus`, `Star`, etc. This commit does a similar thing
with delimiters. It also makes `ast::TokenKind` more similar to
`parser::TokenType`.
This requires a few new methods:
- `TokenKind::is_{,open_,close_}delim()` replace various kinds of
pattern matches.
- `Delimiter::as_{open,close}_token_kind` are used to convert
`Delimiter` values to `TokenKind`.
Despite these additions, it's a net reduction in lines of code. This is
because e.g. `token::OpenParen` is so much shorter than
`token::OpenDelim(Delimiter::Parenthesis)` that many multi-line forms
reduce to single line forms. And many places where the number of lines
doesn't change are still easier to read, just because the names are
shorter, e.g.:
```
- } else if self.token != token::CloseDelim(Delimiter::Brace) {
+ } else if self.token != token::CloseBrace {
```
r? `@petrochenkov`
jsondocck: Require command is at start of line
In one place we use `///``@``` instead of `//``@`.`` The test-runner allowed it, but it probably shouldn't. Ran into by ``@lolbinarycat`` in https://github.com/rust-lang/rust/pull/132748#issuecomment-2816469322:
```
error: unknown disambiguator `?(`
##[error] --> /checkout/tests/rustdoc-json/fns/return_type_alias.rs:3:25
|
3 | ///@ set foo = "$.index[?(``@.name=='Foo')].id"``
| ^^
|
```
Maybe it's also worth erroring on this like we added in #137103
r? ``@GuillaumeGomez``
Fix error when an intra doc link is trying to resolve an empty associated item
Fixes https://github.com/rust-lang/rust/issues/140026.
Assigning ```@nnethercote``` since they're the one who wrote the initial change.
I updated rustdoc code instead of compiler's because I think it makes more sense that the caller ensures on their side that the name they're looking for isn't empty.
r? ```@nnethercote```
bors