Dogfood `-Zno-embed-metadata` in the standard library
This PR dogfoods the [`-Zno-embed-metadata`](https://github.com/rust-lang/cargo/issues/15495) flag in the standard library. This removes the .rmeta portion out of the `libstd.so` file, thus reducing its filesize on disk. Notably, this reduces the amount of MiB that we ship to people who download the standard library.
I think that the only way to find out what this breaks is to try to run full CI, and then try to land it on nightly :)
r? @ghost
mGCA: Move tests for assoc const bindings (formerly ACE) into dedicated directory & replace more mentions of ACE
Split out of PR rust-lang/rust#150843.
As discussed.
Somewhat obvious underlying principle: If the test checks basic or core parts of assoc const bindings and nothing else, move it, otherwise leave it even if it contains ACEs.
Motivation: It makes a lot easier for me to continue working on ACE efficiently.
r? @BoxyUwU
Remove `S-waiting-on-bors` after a PR is merged
I just noticed that we have 50k+ PRs marked as waiting on bors, even though they have been merged, lol.
std: Fix size returned by UEFI tcp4 read operations
The read and read_vectored methods were returning the length of the input buffer, rather than the number of bytes actually read. Fix by changing read_inner to return the correct value, and have both read and read_vectored return that.
Use updated indexes to build reverse map for delegation generics
Fixesrust-lang/rust#150673.
This was a bug that built the `param_def_id_to_index` map with indexes before the new generics were renumbered.
r? @petrochenkov
rustc_parse_format: improve diagnostics for unsupported python numeric grouping
Detect Python-style numeric grouping syntax in format strings (e.g. `{x:,}`)
and emit a clear diagnostic explaining that it is not supported in Rust.
This helps users coming from Python understand the error without exposing
the full set of valid Rust format specifiers.
Use a hook to decouple `rustc_mir_transform` from `rustc_mir_build`
I noticed that the only point of direct contact between the `rustc_mir_transform` and `rustc_mir_build` crates is a single `build_mir` function, which could easily be changed to a hook function instead.
By making that function a hook, we can make `rustc_mir_transform` no longer have a dependency on `rustc_mir_build`, allowing them to be built/rebuilt independently. That should hopefully allow slightly more parallelism in clean builds and incremental rebuilds of the compiler.
build-manifest: Add `rust-mingw` also as extension for "pc-windows-gnu" hosts.
This should enable `rustup component add --target aarch64-pc-windows-gnullvm rust-mingw` when running an `x86_64-pc-windows-gnullvm` toolchain (and vice-versa).
Which itself enables proper cross-compiling of Windows ARM64 binaries on a Windows x64 host without using commercial MSVC.
CC @mati865
- Remove the vacuous `Types`, which provides extremely little value.
- Make sure `src` comes before `dst` in all transmute-related functions.
(Currently it's a mix: sometimes `src` is first, sometimes it is
second`.)
resolve: Use `Macros20NormalizedIdent` in more interfaces
It allows to avoid expensive double normalization in some cases.
This is an attempt to fix the perf regressions from https://github.com/rust-lang/rust/pull/149681.
Also hash spans inside the same file as relative (V2)
Hashes spans relatively to their parent, even if they are not contained inside their parent.
Fixes https://github.com/rust-lang/rust/issues/150400
Closes https://github.com/rust-lang/rust/pull/143882, as this is a successor PR
This PR is very closely based on that PR with a few minor changes, so to give proper credit I made @cjgillot coauthor of the commit.
Reflection MVP
I am opening this PR for discussion about the general design we should start out with, as there are various options (that are not too hard to transition between each other, so we should totally just pick one and go with it and reiterate later)
r? @scottmcm and @joshtriplett
project goal issue: https://github.com/rust-lang/rust-project-goals/issues/406
tracking issue: https://github.com/rust-lang/rust/issues/146922
The design currently implemented by this PR is
* `TypeId::info` (method, usually used as `id.info()` returns a `Type` struct
* the `Type` struct has fields that contain information about the type
* the most notable field is `kind`, which is a non-exhaustive enum over all possible type kinds and their specific information. So it has a `Tuple(Tuple)` variant, where the only field is a `Tuple` struct type that contains more information (The list of type ids that make up the tuple).
* To get nested type information (like the type of fields) you need to call `TypeId::info` again.
* There is only one language intrinsic to go from `TypeId` to `Type`, and it does all the work
An alternative design could be
* Lots of small methods (each backed by an intrinsic) on `TypeId` that return all the individual information pieces (size, align, number of fields, number of variants, ...)
* This is how C++ does it (see https://lemire.me/blog/2025/06/22/c26-will-include-compile-time-reflection-why-should-you-care/ and https://isocpp.org/files/papers/P2996R13.html#member-queries)
* Advantage: you only get the information you ask for, so it's probably cheaper if you get just one piece of information for lots of types (e.g. reimplementing size_of in terms of `TypeId::info` is likely expensive and wasteful)
* Disadvantage: lots of method calling (and `Option` return types, or "general" methods like `num_fields` returning 0 for primitives) instead of matching and field accesses
* a crates.io crate could implement `TypeId::info` in terms of this design
The backing implementation is modular enough that switching from one to the other is probably not an issue, and the alternative design could be easier for the CTFE engine's implementation, just not as nice to use for end users (without crates wrapping the logic)
One wart of this design that I'm fixing in separate branches is that `TypeId::info` will panic if used at runtime, while it should be uncallable
resolve: Factor out and document the glob binding overwriting logic
Also, avoid creating fresh name declarations and overwriting declarations in modules to update some fields in `DeclData`, when possible.
Instead, change the fields directly in `DeclData` using cells.
Unblocks https://github.com/rust-lang/rust/pull/149195.
Update cargo submodule
27 commits in 94c368ad2b9db0f0da5bdd8421cea13786ce4412..8c133afcd5e0d69932fe11f5907683723f8d361d
2025-12-26 19:39:15 +0000 to 2026-01-09 03:50:15 +0000
- Isolate build script metadata progation between std and non-std crates (rust-lang/cargo#16489)
- Add Clippy like lint groups (rust-lang/cargo#16464)
- feat: in-memory only `Manifest` (rust-lang/cargo#16409)
- Fixed incorrect version comparision during build script dependency selection (rust-lang/cargo#16486)
- refactor: new type for unit index (rust-lang/cargo#16485)
- feat(test): Make CARGO_BIN_EXE_ available at runtime (rust-lang/cargo#16421)
- fix(package): detect dirty files when run from workspace member (rust-lang/cargo#16479)
- fix(timing)!: remove `--timings=<FMT>` optional format values (rust-lang/cargo#16420)
- docs(unstable): expand docs for `-Zbuild-analysis` (rust-lang/cargo#16476)
- test: add `-Zunstable-options` with custom targets (rust-lang/cargo#16467)
- feat(report): add cargo report rebuilds (rust-lang/cargo#16456)
- feat(test-support): Use test name for dir when running tests (rust-lang/cargo#16121)
- refactor: Migrate some cases to expect/reason (rust-lang/cargo#16461)
- docs(build-script): clarify OUT_DIR is not cleaned between builds (rust-lang/cargo#16437)
- chore: Update dependencies (rust-lang/cargo#16460)
- Update handlebars to 6.4.0 (rust-lang/cargo#16457)
- chore(deps): update alpine docker tag to v3.23 (rust-lang/cargo#16454)
- Any build scripts can now use cargo::metadata=KEY=VALUE (rust-lang/cargo#16436)
- fix(log): add `dependencies` field to `UnitRegistered` (rust-lang/cargo#16448)
- Implement fine grain locking for `build-dir` (rust-lang/cargo#16155)
- feat(resolver): List features when no close match (rust-lang/cargo#16445)
- feat(report): new command `cargo report sessions` (rust-lang/cargo#16428)
- feat (patch): Display where the patch was defined in patch-related error messages (rust-lang/cargo#16407)
- test(build-rs): Reduce from 'build' to 'check' where possible (rust-lang/cargo#16444)
- feat(toml): TOML 1.1 parse support (rust-lang/cargo#16415)
- feat(report): support --manifest-path in `cargo report timings` (rust-lang/cargo#16441)
- fix(vendor): recursively filter git files in subdirectories (rust-lang/cargo#16439)
Rollup of 11 pull requests
Successful merges:
- rust-lang/rust#150272 (docs(core): update `find()` and `rfind()` examples)
- rust-lang/rust#150385 (fix `Expr::can_have_side_effects` for `[x; N]` style array literal and binary expressions)
- rust-lang/rust#150561 (Finish transition from `semitransparent` to `semiopaque` for `rustc_macro_transparency`)
- rust-lang/rust#150574 (Clarify `MoveData::init_loc_map`.)
- rust-lang/rust#150762 (Use functions more in rustdoc GUI tests)
- rust-lang/rust#150808 (rename the `derive_{eq, clone_copy}` features to `*_internals`)
- rust-lang/rust#150816 (Fix trait method anchor disappearing before user can click on it)
- rust-lang/rust#150821 (tests/ui/borrowck/issue-92157.rs: Remove (bug not fixed))
- rust-lang/rust#150829 (make attrs actually use `Target::GenericParam`)
- rust-lang/rust#150834 (Add tracking issue for `feature(multiple_supertrait_upcastable)`)
- rust-lang/rust#150864 (The aarch64-unknown-none target requires NEON, so the docs were wrong.)
r? @ghost
Add tracking issue for `feature(multiple_supertrait_upcastable)`
Move feature(multiple_supertrait_upcastable) to the actual feature gates section (from the internal feature gates section) and give it a tracking issue.
Tracking issue: rust-lang/rust#150833
Fixes https://github.com/rust-lang/rust/issues/150773
This feature is for the `multiple_supertrait_upcastable` lint, which was added as `unstable` without a tracking issue, but was placed in the internal feature gates section. This PR moves its listing to the actual feature gates section and gives it a tracking issue.
If the lint is intended to stay internal-only, then this can be changed to instead mark it as `internal` (and maybe close the tracking issue).
make attrs actually use `Target::GenericParam`
currently attributes lower `GenericParam` -> `Target::Param` this PR fixes this, so that `GenericParam` is lowered to `Target::GenericParam`
r? @JonathanBrouwer
tests/ui/borrowck/issue-92157.rs: Remove (bug not fixed)
The bug the test tests for is masked by the wrong `#[lang = "start"]` signature. If the signature is corrected, the test builds. But that is not because the bug is fixed, but because the test has been changed too much from the original reproducer. The original reproducer still ICE:s. See https://github.com/rust-lang/rust/issues/92157#issuecomment-3722060317.
But that's fine since in the latest compiler says:
> note: using internal features is not supported and expected to cause internal compiler errors when used incorrectly
So let's remove the test and close the issue as "won't fix". See https://github.com/rust-lang/rust/issues/92157#issuecomment-3725036997.
r? @JohnTitor since you added the test in https://github.com/rust-lang/rust/pull/106878
Fix trait method anchor disappearing before user can click on it
A good example of this bug is going to https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir_analysis/collect/struct.ItemCtxt.html#impl-HirTyLowerer%3C'tcx%3E-for-ItemCtxt%3C'tcx%3E, and then try to click on the `§` anchor of the `tcx` method.
The solution to this bug is to simply "glue" the anchor to the method, so when the mouse cursor moves to it, there is no gap between the two, preventing the anchor to disappear (hopefully this explanation doesn't make sense only to me ^^').
First commit fixes the bug by expanding the anchor size.
Second commit is a small clean-up of the GUI test.
Third commit actually adds the GUI regression test.
cc @BoxyUwU
r? @camelid
rename the `derive_{eq, clone_copy}` features to `*_internals`
Features like `derive_from` and `derive_coerce_pointee` refer to actual unstable derive macros, but the `derive_eq` and `derive_clone_copy` features are internal hacks. Rename them accordingly by adding the suffix `_internals`.
Use functions more in rustdoc GUI tests
Now that conditions are supported in `browser-ui-test`, we can start simplify some parts of the tests. This is a first cleanup, but I guess a lot more could be simplified. For follow-ups I guess. :)
I made some improvements in backtrace display in `browser-ui-test`, hence the version update once more.
r? @lolbinarycat
Clarify `MoveData::init_loc_map`.
Change the `SmallVec` size from 4 to 1, because that's sufficient in the vast majority of cases. (This doesn't affect performance in practice, so it's more of a code clarity change than a performance change.)
r? @cjgillot
Finish transition from `semitransparent` to `semiopaque` for `rustc_macro_transparency`
Since it's a bit annoying to have different names for the same thing.
My understanding is that this is just internal stuff that is not part of any public API even tough rust-analyzer knows about it.
Continuation of
- https://github.com/rust-lang/rust/pull/139084.
Discovered while investigating
- https://github.com/rust-lang/rust/issues/150514
fix `Expr::can_have_side_effects` for `[x; N]` style array literal and binary expressions
AFAIK `[0; 3]` is basically a syntax sugar for `[0, 0, 0]` so it should return whether the repeat's element can have side effects, like what it does on arrays.
And it seems that the rule for unary operators and indexings can be applied to binary operators as well.
naked functions: emit `.private_extern` on macos
fixes https://github.com/rust-lang/rust/issues/148307
Emit `.private_extern` on macos when the naked function uses `Linkage::Internal`. Failing to do so can cause issues with LTO.
The documentation on this directive is kind of sparse, but I believe this is at least not incorrect, and does fix the issue.
r? @Amanieu
cc @bjorn3
`Vec::push` in consts MVP
Example:
```rust
const X: &'static [u32] = {
let mut v = Vec::with_capacity(6);
let mut x = 1;
while x < 42 {
v.push(x);
x *= 2;
}
assert!(v.len() == 6);
v.const_make_global()
};
assert_eq!([1, 2, 4, 8, 16, 32], X);
```
Oh this is fun...
* We split out the implementation of `Global` such that it calls `intrinsics::const_allocate` and `intrinsics::const_deallocate` during compile time. This is achieved using `const_eval_select`
* This allows us to `impl const Allocator for Global`
* We then constify everything necessary for `Vec::with_capacity` and `Vec::push`.
* Added `Vec::const_make_global` to leak and intern the final value via `intrinsics::const_make_global`. If we see any pointer in the final value of a `const` that did not call `const_make_global`, we error as implemented in rust-lang/rust#143595.
r? `@rust-lang/wg-const-eval`
To-do for me:
* [x] Assess the rustdoc impact of additional bounds in the method
* [x] ~~Increase test coverage~~ I think this is enough for an unstable feature.
Merge `associated_const_equality` feature gate into MGCA
Tracking Issues: rust-lang/rust#132980rust-lang/rust#92827
Merge `associated_const_equality`(ACE) feature gate into `min_generic_const_args`(MGCA).
- Replaces `features().associated_const_equality()` checks with `features().min_generic_const_args()`
- Updates the parser to gate associated const equality under `min_generic_const_args`
- Moves `associated_const_equality` to the removed features list
- Removes the `associated_const_equality` method from the `Features` trait
- Updates all affected tests and tools (rust-analyzer, clippy)
Closesrust-lang/rust#150617
r? `@BoxyUwU`
This removes `associated_const_equality` as a separate feature gate and makes it part of `min_generic_const_args` (mgca).
Key changes:
- Remove `associated_const_equality` from unstable features, add to removed
- Update all test files to use `min_generic_const_args` instead
- Preserve the original "associated const equality is incomplete" error message by specially handling `sym::associated_const_equality` spans in `feature_gate.rs`
- Rename FIXME(associated_const_equality) to FIXME(mgca)
Add specialization for `deque1.prepend(deque2.drain(range))` (VecDeque::prepend and extend_front)
Tracking issue: rust-lang/rust#146975
This specialization makes sure `deque1.prepend(deque2.drain(..))` gets similar speed to `deque1.append(&mut deque2)`. `deque1.prepend(deque2.drain(..))` is the equivalent of `deque1.append(&mut deque2)` but appending to the front (see the [second example of prepend](https://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.prepend), prepend is from the same tracking issue).
