From `#[align]` -> `#[rustc_align]`. Attributes starting with `rustc`
are always perma-unstable and feature-gated by `feature(rustc_attrs)`.
See regression RUST-143834.
For the underlying problem where even introducing new feature-gated
unstable built-in attributes can break user code such as
```rs
macro_rules! align {
() => {
/* .. */
};
}
pub(crate) use align; // `use` here becomes ambiguous
```
refer to RUST-134963.
Since the `#[align]` attribute is still feature-gated by
`feature(fn_align)`, we can rename it as a mitigation. Note that
`#[rustc_align]` will obviously mean that current unstable user code
using `feature(fn_aling)` will need additionally `feature(rustc_attrs)`,
but this is a short-term mitigation to buy time, and is expected to be
changed to a better name with less collision potential.
See
<https://rust-lang.zulipchat.com/#narrow/channel/238009-t-compiler.2Fmeetings/topic/.5Bweekly.5D.202025-07-17/near/529290371>
where mitigation options were considered.
(cherry picked from commit 69b71e4410)
Key changes include:
- Removal of the word "syntax" from the lint message. More accurately,
it could have been something like "syntax group" or "syntax
category", but avoiding it completely is easier.
- The primary lint message now reflects exactly which mismatch is
occurring, instead of trying to be general. A new `help` line is
general across the mismatch kinds.
- Suggestions have been reduced to be more minimal, no longer also
changing non-idiomatic but unrelated aspects.
- Suggestion text no longer mentions changes when those changes don't
occur in that specific suggestion.
(cherry picked from commit 5530744318)
As a temporary measure while a proper fix for
`tests/ui/sized-hierarchy/incomplete-inference-issue-143992.rs`
is implemented, make `MetaSized` obligations always hold. In effect,
temporarily reverting the `sized_hierarchy` feature. This is a small
change that can be backported.
(cherry picked from commit 8d64937dc2)
Several UI tests have a `normalize-stderr` for "you are using x.y.z"
rustc versions, and that regex is flexible enough for suffixes like
"-nightly" and "-dev", but not for "-beta.N". We can just add '.' to
that trailing pattern to include this.
(cherry picked from commit 8469966710)
Document subdirectories of UI tests with README files
Part of rust-lang/rust#133895 and the [2025 Google Summer of Code](https://blog.rust-lang.org/2025/05/08/gsoc-2025-selected-projects/) associated project.
When adding a new UI test, one is faced with hundreds of subdirectories in `tests/ui` reflecting various categories. Knowing where to put the new test is not trivial, as many of the categories have slightly misleading names. For example, `moves` does not only refer to the `move` keyword but to functions taking ownership in general, whereas `allocator` does not refer to allocation in general but rather to the very specific `allocator_api` and `global_allocator` features.
Many contributors will therefore place their test at the top level of ̀`tests/ui` where it will be mixed with hundreds of unrelated tests.
This PR is a tentative move towards more clearly defined tag/categories, with a SUMMARY.md file documenting the true purpose of each subdirectory, placed inside `tests/ui`.
r? ``@jieyouxu``
Skip no-op drop glue
Since rust-lang/rust#122662 this no longer gets used in vtables, so we're safe to fully
drop generating functions from vtables. Those are eventually cleaned up
by LLVM, but it's wasteful to produce them in the first place.
This doesn't appear to be a significant win (and shows some slight regressions) but
seems like the right thing to do. At minimum it reduces noise in the LLVM IR we generate,
which seems like a good thing.
Rollup of 10 pull requests
Successful merges:
- rust-lang/rust#142458 (Merge unboxed trait object error suggestion into regular dyn incompat error)
- rust-lang/rust#142593 (Add a warning to LateContext::get_def_path)
- rust-lang/rust#142594 (Add DesugaringKind::FormatLiteral)
- rust-lang/rust#142740 (Clean-up `FnCtxt::is_destruct_assignment_desugaring`)
- rust-lang/rust#142780 (Port `#[must_use]` to new attribute parsing infrastructure)
- rust-lang/rust#142798 (Don't fail to parse a struct if a semicolon is used to separate fields)
- rust-lang/rust#142856 (Add a few inline directives in rustc_serialize.)
- rust-lang/rust#142868 (remove few allow(dead_code))
- rust-lang/rust#142874 (cranelift: fix target feature name typo: "fxsr")
- rust-lang/rust#142877 (Document why tidy checks if `eslint` is installed via `npm`)
r? `@ghost`
`@rustbot` modify labels: rollup
Add DesugaringKind::FormatLiteral
Implements `DesugaringKind::FormatLiteral` to mark the FormatArgs desugaring of format literals. The main use for this is to stop yapping about about formatting parameters if we're not anywhere near a format literal. The other use case is to fix suggestions such as https://github.com/rust-lang/rust/issues/141350. It might also be useful for new or existing diagnostics that check whether they're in a format-like macro.
cc `@xizheyin` `@fmease`
Merge unboxed trait object error suggestion into regular dyn incompat error
Another hir-walker removed from the well-formed queries. This error was always a duplicate of another, but it was able to provide more information because it could invoke `is_dyn_compatible` without worrying about cycle errors. That's also the reason we can't put the error directly into hir_ty_lowering when lowering a `dyn Trait` within an associated item signature. So instead I packed it into the error handling of wf obligation checking.
completely deduplicate `Visitor` and `MutVisitor`
r? oli-obk
This closesrust-lang/rust#127615.
### Discussion
> * Give every `MutVisitor::visit_*` method a corresponding `flat_map_*` method.
Not every AST node exists in a location where they can be mapped to multiple instances of themselves. Not every AST node exists in a location where they can be removed from existence (e.g. `filter_map_expr`). I don't think this is doable.
> * Give every `MutVisitor::visit_*` method a corresponding `Visitor` method and vice versa
The only three remaining method-level asymmetries after this PR are `visit_stmt` and `visit_nested_use_tree` (only on `Visitor`) and `visit_span` (only on `MutVisitor`).
`visit_stmt` doesn't seem applicable to `MutVisitor` because `walk_flat_map_stmt_kind` will ask `flat_map_item` / `filter_map_expr` to potentially turn a single `Stmt` to multiple based on what a visitor wants. So only using `flat_map_stmt` seems appropriate.
`visit_nested_use_tree` is used for `rustc_resolve` to track stuff. Not useful for `MutVisitor` for now.
`visit_span` is currently not used for `MutVisitor` already, it was just kept in case we want to revive rust-lang/rust#127241. cc `@cjgillot` maybe we could remove for now and re-insert later if we find a use-case? It does involve some extra effort to maintain.
* Remaining FIXMEs
`visit_lifetime` has an extra param for `Visitor` that's not in `MutVisitor`. This is again something only used by `rustc_resolve`. I think we can keep that symmetry for now.
Enable textrel-on-minimal-lib for Windows
`bin_name` needs to be used when building a runnable executable.
Addresses item in rust-lang/rust#128602
---
try-job: x86_64-mingw-*
try-job: x86_64-msvc-*
try-job: i686-msvc-*
Enable fmt-write-bloat for Windows
Seems to be working fine for MSVC once it has the correct binary name.
Addresses item in rust-lang/rust#128602
---
try-job: x86_64-mingw-*
try-job: x86_64-msvc-*
try-job: i686-msvc-*
All HIR attributes are outer
Fixes https://github.com/rust-lang/rust/issues/142649. Closes https://github.com/rust-lang/rust/pull/142759.
All HIR attributes, including parsed and not yet parsed, will now be rendered as outer attributes by `rustc_hir_pretty`. The original style of the corresponding AST attribute(s) is not relevant for pretty printing, only for diagnostics.
r? ````@jdonszelmann````
forward the bootstrap `runner` to `run-make`
The runner was already forwarded to `compiletest`, this just passes it on to `run-make` and uses it in the `run` functions.
The configuration can look like this
```toml
# in bootstrap.toml
[target.s390x-unknown-linux-gnu]
runner = "qemu-s390x -L /usr/s390x-linux-gnu"
```
Any C compilation automatically sets the correct target. Calls to rustc must use `.target(target())`. Then, a command like below will work by cross-compiling to the given target, and using the given runner for that target to execute the binary:
```
./x test tests/run-make/c-link-to-rust-va-list-fn --target s390x-unknown-linux-gnu
```
The runner can also be used for e.g. running with `valgrind`.
This PR also enables its use in the test case that I care about, hopefully that actually does work on the platforms that CI uses. We should probably run some try jobs to be sure?
r? `@jieyouxu`
try-job: test-various
try-job: armhf-gnu
Since 122662 this no longer gets used in vtables, so we're safe to fully
drop generating these empty functions. Those are eventually cleaned up
by LLVM, but it's wasteful to produce them in the first place.
This also adds a missing test for fn-ptr casts, which do still need to
generate no-op drop glue. It's possible a future optimization could
point all of those at the same drop glue (e.g., for *mut ()) rather than
for each separate type, but that would require extra work for CFI and
isn't particularly easy to do anyway.
Only traverse reachable blocks in JumpThreading.
Fixes https://github.com/rust-lang/rust/issues/131451
We only compute loop headers for reachable blocks. We shouldn't try to perform an opt on unreachable blocks anyway.
Improve diagnostics for `concat_bytes!` with C string literals
Use the same error as other invalid types for `concat_bytes!`, rather
than using `ConcatCStrLit` from `concat!`. Also add more information
with a note about why this doesn't work, and a suggestion to use a
null-terminated byte string instead.
add doc(alias("AsciiChar")) to core::ascii::Char
Added it to the reexported, which is intended rustdoc behavior, but is apparently untested, so I also added a test for it.
Add diagnostic items for Clippy
Clippy still uses some paths to access items from the standard library. Adding the missing diagnostic items allows removing the last remaining paths.
Closesrust-lang/rust-clippy#5393
error on calls to ABIs that cannot be called
We recently added `extern "custom"`, which cannot be called using a rust call expression. But there are more ABIs that can't be called in that way, because the call does not semantically make sense.
More details are in https://github.com/rust-lang/rust/issues/140566#issuecomment-2846205457
r? `@workingjubilee`
try-job: x86_64-gnu-llvm-19-3
rustdoc_json: improve handling of generic args
This PR fixes some inconsistencies and inefficiencies in how generic args are handled by rustdoc-json-types.
r? `@aDotInTheVoid`
They show up in three places: once as `Option<Box<GenericArgs>>`, once
as `Box<GenericArgs>`, and once as `GenericArgs`. The first option is
best. It is more compact because generic args are often missing. This
commit changes the latter two to the former.
Example output, before and after, for the `AssocItemConstraint` change:
```
{"name":"Offset","args":{"angle_bracketed":{"args":[],"constraints":[]}},"binding":{...}}
{"name":"Offset","args":null,"binding":{...}}
```
Example output, before and after, for the `Type::QualifiedPath` change:
```
{"qualified_path":{"name":"Offset","args":{"angle_bracketed":{"args":[],"constraints":[]}}, ...}}
{"qualified_path":{"name":"Offset","args":null, ...}}
```
This reduces JSON output size, but not by much (e.g. 0.5%), because
`AssocItemConstraint` and `Type::QualifiedPath` are uncommon.
