Add an issue template for future-incompatible lints
This adds a GitHub issue template for future-incompatible lints. Most of the existing tracking issues have been using different formats with different information, and I think it would be helpful to make them a little more consistent and to ensure that sufficient information is provided.
Some comments on my choices:
* Added a dedicated section to describe *why* the change is being made. Many existing issues already have this, so let's standardize on it.
* Have a section with a very clear example. Almost all of the existing issues have this in one form or another.
* Added a "Recommendations" section, since this is something I see missing in several of the existing issues, and this is really important information IMHO.
* I reworded the "When" section. The existing template mentioned that these get reviewed every 6 weeks which my understanding is not true. That's also not very helpful information to the user, since it doesn't really answer the question. I'm not sure this section will actually be useful since I suspect most of the time we don't know when it will change (there have been a few exceptions).
* Clearly show the expected progression steps. Several issues already have this.
* Added implementation history, which is useful for linking PRs. (IDK, this could get merged with "Steps".)
Stage0 bootstrap update
This PR [follows the release process](https://forge.rust-lang.org/release/process.html#master-bootstrap-update-tuesday) to update the stage0 compiler.
The only thing of note is 58651d1b31, which was flagged by clippy as a correctness fix. I think allowing that lint in our case makes sense, but it's worth to have a second pair of eyes on it.
r? `@Mark-Simulacrum`
Do not remove `super` keyword from `super let`
This is affecting a macro in the standard library:
bc7512ee63/library/core/src/pin.rs (L1945)
I added an exception in 6f6a9a585891d0a2d1114a7a621f35f28f39c0d9, but I'd like to remove it eventually, so opening this in-tree to not block this on the next rustfmt sync.
r? `@calebcartwright` or `@ytmimi`
cg_llvm: Clean up some inline assembly bindings
This PR combines a few loosely-related cleanups to LLVM bindings related to inline assembly. These include:
- Replacing `LLVMRustInlineAsm` with LLVM-C's `LLVMGetInlineAsm`
- Adjusting FFI declarations to avoid the need for explicit `as_c_char_ptr` conversions
- Flattening control flow in `inline_asm_call`
There should be no functional changes.
cg_llvm: Rename `OperandBundleOwned` to `OperandBundleBox`
As with `DIBuilderBox`, the "Box" suffix does a better job of communicating that this is an owning pointer to some borrowable resource.
This also renames the `raw` method to `as_ref`, which is what it would have been named originally if the `Deref` problem (#137603) had been known at the time.
No functional change.
Remove mono item collection strategy override from -Zprint-mono-items
Previously `-Zprint-mono-items` would override the mono item collection
strategy. When debugging one doesn't want to change the behaviour, so
this was counter productive. Additionally, the produced behaviour was
artificial and might never arise without using the option in the first
place (`-Zprint-mono-items=eager` without `-Clink-dead-code`). Finally,
the option was incorrectly marked as `UNTRACKED`.
Resolve those issues, by turning `-Zprint-mono-items` into a boolean
flag that prints results of mono item collection without changing the
behaviour of mono item collection.
For codegen-units test incorporate `-Zprint-mono-items` flag directly
into compiletest tool.
Test changes are mechanical. `-Zprint-mono-items=lazy` was removed
without additional changes, and `-Zprint-mono-items=eager` was turned
into `-Clink-dead-code`. Linking dead code disables internalization, so
tests have been updated accordingly.
Merge typeck loop with static/const item eval loop
r? `@ghost`
Let's try a small one first. Doing this in general has some bad cache coherence issues because the query caches are laid out in `Vec<QueryResult>` lists per query where each index refers to a `DefId` in the same order as we're iterating. Iterating two or more lists at the same time does have cache issues, so I want to poke a bit at it to see if we can't merge just a few of them at a time.
Previously `-Zprint-mono-items` would override the mono item collection
strategy. When debugging one doesn't want to change the behaviour, so
this was counter productive. Additionally, the produced behaviour was
artificial and might never arise without using the option in the first
place (`-Zprint-mono-items=eager` without `-Clink-dead-code`). Finally,
the option was incorrectly marked as `UNTRACKED`.
Resolve those issues, by turning `-Zprint-mono-items` into a boolean
flag that prints results of mono item collection without changing the
behaviour of mono item collection.
For codegen-units test incorporate `-Zprint-mono-items` flag directly
into compiletest tool.
Test changes are mechanical. `-Zprint-mono-items=lazy` was removed
without additional changes, and `-Zprint-mono-items=eager` was turned
into `-Clink-dead-code`. Linking dead code disables internalization, so
tests have been updated accordingly.
Fix linking statics on Arm64EC
Arm64EC builds recently started to fail due to the linker not finding a symbol:
```
symbols.o : error LNK2001: unresolved external symbol #_ZN3std9panicking11EMPTY_PANIC17hc8d2b903527827f1E (EC Symbol)
C:\Code\hello-world\target\arm64ec-pc-windows-msvc\debug\deps\hello_world.exe : fatal error LNK1120: 1 unresolved externals
```
It turns out that `EMPTY_PANIC` is a new static variable that was being exported then imported from the standard library, but when exporting LLVM didn't prepend the name with `#` (as only functions are prefixed with this character), whereas Rust was prefixing with `#` when attempting to import it.
The fix is to have Rust not prefix statics with `#` when importing.
Adding tests discovered another issue: we need to correctly mark static exported from dylibs with `DATA`, otherwise MSVC's linker assumes they are functions and complains that there is no exit thunk for them.
CI found another bug: we only apply `DllImport` to non-local statics that aren't foreign items (i.e., in an `extern` block), that is we want to use `DllImport` for statics coming from other Rust crates. However, `__rust_no_alloc_shim_is_unstable` is a static generated by the Rust compiler if required, but downstream crates consider it a foreign item since it is declared in an `extern "Rust"` block, thus they do not apply `DllImport` to it and so fails to link if it is exported by the previous crate as `DATA`. The fix is to apply `DllImport` to foreign items that are marked with the `rustc_std_internal_symbol` attribute (i.e., we assume they aren't actually foreign and will be in some Rust crate).
Fixes#138541
---
try-job: dist-aarch64-msvc
try-job: dist-x86_64-msvc
try-job: x86_64-msvc-1
try-job: x86_64-msvc-2
Rollup of 8 pull requests
Successful merges:
- #140095 (Eliminate `word_and_empty` methods.)
- #140341 (Clarify black_box warning a bit)
- #140684 (Only include `dyn Trait<Assoc = ...>` associated type bounds for `Self: Sized` associated types if they are provided)
- #140707 (Structurally normalize in range pattern checking in HIR typeck)
- #140716 (Improve `-Zremap-path-scope` tests with dependency)
- #140800 (Make `rustdoc-tempdir-removal` run-make tests work on other platforms than linux)
- #140802 (Add release notes for 1.87.0)
- #140811 (Enable triagebot note functionality for rust-lang/rust)
r? `@ghost`
`@rustbot` modify labels: rollup
Only include `dyn Trait<Assoc = ...>` associated type bounds for `Self: Sized` associated types if they are provided
Since #136458, we began filtering out associated types with `Self: Sized` bounds when constructing the list of associated type bounds to put into our `dyn Trait` types. For example, given:
```rust
trait Trait {
type Assoc where Self: Sized;
}
```
After #136458, even if a user writes `dyn Trait<Assoc = ()>`, the lowered ty would have an empty projection list, and thus be equivalent to `dyn Trait`. However, this has the side effect of no longer constraining any types in the RHS of `Assoc = ...`, not implying any WF implied bounds, and not requiring that they hold when unsizing.
After this PR, we include these bounds, but (still) do not require that they are provided. If the are not provided, they are skipped from the projections list.
This results in `dyn Trait` types that have differing numbers of projection bounds. This will lead to re-introducing type mismatches e.g. between `dyn Trait` and `dyn Trait<Assoc = ()>`. However, this is expected and doesn't suffer from any of the deduplication unsoundness from before #136458.
We may want to begin to ignore thse bounds in the future by bumping `unused_associated_type_bounds` to an FCW. I don't want to tangle that up into the fix that was originally intended in #136458, so I'm doing a "fix-forward" in this PR and deferring thinking about this for the future.
Fixes#140645
r? lcnr
Do not deny warnings in "fast" try builds
When we do the classic ``@bors` try` build without specifying `try-job` in the PR description, we want to get a compiler toolchain for perf./crater/local experimentation as fast as possible. We don't run any tests in that case, so it seems reasonable to also ignore warnings.
Fixes: https://github.com/rust-lang/rust/issues/140753
r? `@jieyouxu`
try-job: dist-x86_64-linux
make it possible to run in-tree rustfmt with `x run rustfmt`
Currently, there is no way to run in-tree `rustfmt` using `x fmt` or `x test tidy` commands. This PR implements `rustfmt` on `x run`, which allows bootstrap to run the in-tree `rustfmt`.
Fixes#140723
allow deref patterns to participate in exhaustiveness analysis
Per [this proposal](https://hackmd.io/4qDDMcvyQ-GDB089IPcHGg#Exhaustiveness), this PR allows deref patterns to participate in exhaustiveness analysis. Currently all deref patterns enforce `DerefPure` bounds on their scrutinees, so this assumes all patterns it's analyzing are well-behaved. This also doesn't support [mixed exhaustiveness](https://hackmd.io/4qDDMcvyQ-GDB089IPcHGg#Mixed-exhaustiveness), and instead emits an error if deref patterns are used together with normal constructors. I think mixed exhaustiveness would be nice to have (especially if we eventually want to support arbitrary `Deref` impls[^1]), but it'd require more work to get reasonable diagnostics[^2].
Tracking issue for deref patterns: #87121
r? `@Nadrieril`
[^1]: Regardless of whether we support limited exhaustiveness checking for untrusted `Deref` or always require other arms to be exhaustive, I think it'd be useful to allow mixed matching for user-defined smart pointers. And it'd be strange if it worked there but not for `Cow`.
[^2]: I think listing out witnesses of non-exhaustiveness can be confusing when they're not necessarily disjoint, and when you only need to cover some of them, so we'd probably want special formatting and/or explanatory subdiagnostics. And if it's implemented similarly to unions, we'd probably also want some way of merging witnesses; the way witnesses for unions can appear duplicated is pretty unfortunate. I'm not sure yet how the diagnostics should look, especially for deeply nested patterns.
run-make-support: set rustc dylib path for cargo wrapper
Some run-make tests invoke Cargo via run_make_support::cargo(), but fail to execute correctly when rustc is built without rpath. In these setups, runtime loading of rustc’s shared libraries fails unless the appropriate dynamic library path is set manually.
This commit updates the cargo() wrapper to call set_host_compiler_dylib_path(), aligning its behavior with the existing rustc() wrapper: f76c7367c6/src/tools/run-make-support/src/external_deps/rustc.rs (L39-L43)
This ensures that Cargo invocations during tests inherit the necessary dylib paths, avoiding errors related to missing shared libraries in rpath-less builds.
Fixes part of #140738
add armv5te-unknown-linux-gnueabi target maintainer
My employer is interested in having this target maintained and we already have some tests in our CI running for it.
armv5te-unknown-linux-gnueabi can be ticket off in #113739.
Fix regression from #140393 for espidf / horizon / nuttx / vita
#140393 introduced changes to the layout of the `std::sys::process` code.
As a result, the Tier 3 ESP-IDF (and I suspect Horizon, Nuttx and Vita targets as well) no longer build.
A `pub use unsupported::output` is all that was missing - for the above OSes specifically. This explicit `pub use` is now necessary, because #140393 moved the `output` function to module-level, where it was previously part of `Command` and was thus re-exported automatically, as part of the `imp::Command` re-export further down the file containing the one-liner fix.
Note that - with the change introduced by #140393 - we **can't** anymore just do an unconditional `pub use imp::output` as this function simply does not exist anymore anywhere else but in the `unsupported` module.
r? `@joboet`
[rustdoc] Ensure that temporary doctest folder is correctly removed even if doctests failed
Fixes#139899.
The bug was due to the fact that if any doctest fails for any reason, we call `exit` (or it's called inside `libtest` if not edition 2024), meaning that `TempDir`'s destructor isn't called, and therefore the temporary folder isn't cleaned up.
Took me a while to figure out how to reproduce but finally I was able to reproduce the bug with:
`````rust
#![doc(test(attr(deny(warnings))))]
//! ```
//! let a = 12;
//! ```
`````
And then I ensured that panicking doctests were cleaned up as well:
`````rust
//! ```
//! panic!();
//! ```
`````
And finally I checked if it was fixed for merged doctests too (`--edition 2024`).
To make this work, I needed to add a new public function in `libtest` too which would call a function once all tests have been run.
So only issue is: I have absolutely no idea how we can add a regression test for this fix. If anyone has an idea...
r? `@notriddle`
Don't crash on error codes passed to `--explain` which exceed our internal limit of 9999
removed panic in case where we do `--explain > 9999` and added check for it
now error looks like this instead of ICE
```
$ rustc.exe --explain E10000
error: E10000 is not a valid error code
```
fixes#140647
r? `@fmease`
Parser: Recover error from named params while parse_path
Fixes#140169
I added test to the first commit and the second added the code and changes to test.
r? `@petrochenkov`
Separate dataflow analysis and results
`Analysis` gets put into `Results` with `EntryStates`, by `iterate_to_fixpoint`. This has two problems:
- `Results` is passed various places where only `Analysis` is needed.
- `EntryStates` is passed around mutably everywhere even though it is immutable.
This commit mostly separates `Analysis` from `Results` and fixes these two problems.
r? `@davidtwco`
Use thread local dep graph encoding
This adds thread local encoding of dep graph nodes. Each thread has a `MemEncoder` that gets flushed to the global `FileEncoder` when it exceeds 64 kB. Each thread also has a local cache of dep indices. This means there can now be empty gaps in `SerializedDepGraph`.
Indices are marked green and also allocated by the new atomic operation `DepNodeColorMap::try_mark_green` as the encoder lock is removed.
Stabilize proc_macro::Span::{file, local_file}.
Stabilizes this part of https://github.com/rust-lang/rust/issues/54725:
```rust
impl Span {
pub fn file(&self) -> String; // Mapped/artificial file name, for display purposes.
pub fn local_file(&self) -> Option<PathBuf>; // Real file name as it exists on the local file system.
}
```
See also the naming discussion in https://github.com/rust-lang/rust/issues/139903
Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type
This removes `Definitions.next_disambiguator` as it doesn't guarantee deterministic def paths when `create_def` is called in parallel. Instead a new `DisambiguatorState` type is passed as a mutable reference to `create_def` to help create unique def paths. `create_def` calls with distinct `DisambiguatorState` instances must ensure that that the def paths are unique without its help.
Anon associated types did rely on this global state for uniqueness and are changed to use (method they're defined in + their position in the method return type) as the `DefPathData` to ensure uniqueness. This also means that the method they're defined in appears in error messages, which is nicer.
`DefPathData::NestedStatic` is added to use for nested data inside statics instead of reusing `DefPathData::AnonConst` to avoid conflicts with those.
cc `@oli-obk`
Initial support for dynamically linked crates
This PR is an initial implementation of [rust-lang/rfcs#3435](https://github.com/rust-lang/rfcs/pull/3435) proposal.
### component 1: interface generator
Interface generator - a tool for generating a stripped version of crate source code. The interface is like a C header, where all function bodies are omitted. For example, initial crate:
```rust
#[export]
#[repr(C)]
pub struct S {
pub x: i32
}
#[export]
pub extern "C" fn foo(x: S) {
m1::bar(x);
}
pub fn bar(x: crate::S) {
// some computations
}
```
generated interface:
```rust
#[export]
#[repr(C)]
pub struct S {
pub x: i32,
}
#[export]
pub extern "C" fn foo(x: S);
pub fn bar(x: crate::S);
```
The interface generator was implemented as part of the pretty-printer. Ideally interface should only contain exportable items, but here is the first problem:
- pass for determining exportable items relies on privacy information, which is totally available only in HIR
- HIR pretty-printer uses pseudo-code(at least for attributes)
So, the interface generator was implemented in AST. This has led to the fact that non-exportable items cannot be filtered out, but I don't think this is a major issue at the moment.
To emit an interface use a new `sdylib` crate type which is basically the same as `dylib`, but it doesn't contain metadata, and also produces the interface as a second artifact. The current interface name is `lib{crate_name}.rs`.
#### Why was it decided to use a design with an auto-generated interface?
One of the main objectives of this proposal is to allow building the library and the application with different compiler versions. This requires either a metadata format compatible across rustc versions or some form of a source code. The option with a stable metadata format has not been investigated in detail, but it is not part of RFC either. Here is the the related discussion: https://github.com/rust-lang/rfcs/pull/3435#discussion_r1202872373
Original proposal suggests using the source code for the dynamic library and all its dependencies. Metadata is obtained from `cargo check`. I decided to use interface files since it is more or less compatible with the original proposal, but also allows users to hide the source code.
##### Regarding the design with interfaces
in Rust, files generally do not have a special meaning, unlike C++. A translation unit i.e. a crate is not a single file, it consists of modules. Modules, in turn, can be declared either in one file or divided into several. That's why the "interface file" isn't a very coherent concept in Rust. I would like to avoid adding an additional level of complexity for users until it is proven necessary. Therefore, the initial plan was to make the interfaces completely invisible to users i. e. make them auto-generated. I also planned to put them in the dylib, but this has not been done yet. (since the PR is already big enough, I decided to postpone it)
There is one concern, though, which has not yet been investigated(https://github.com/rust-lang/rust/pull/134767#issuecomment-2736471828):
> Compiling the interface as pretty-printed source code doesn't use correct macro hygiene (mostly relevant to macros 2.0, stable macros do not affect item hygiene). I don't have much hope for encoding hygiene data in any stable way, we should rather support a way for the interface file to be provided manually, instead of being auto-generated, if there are any non-trivial requirements.
### component 2: crate loader
When building dynamic dependencies, the crate loader searches for the interface in the file system, builds the interface without codegen and loads it's metadata. Routing rules for interface files are almost the same as for `rlibs` and `dylibs`. Firstly, the compiler checks `extern` options and then tries to deduce the path himself.
Here are the code and commands that corresponds to the compilation process:
```rust
// simple-lib.rs
#![crate_type = "sdylib"]
#[extern]
pub extern "C" fn foo() -> i32 {
42
}
```
```rust
// app.rs
extern crate simple_lib;
fn main() {
assert!(simple_lib::foo(), 42);
}
```
```
// Generate interface, build library.
rustc +toolchain1 lib.rs
// Build app. Perhaps with a different compiler version.
rustc +toolchain2 app.rs -L.
```
P.S. The interface name/format and rules for file system routing can be changed further.
### component 3: exportable items collector
Query for collecting exportable items. Which items are exportable is defined [here](https://github.com/m-ou-se/rfcs/blob/export/text/0000-export.md#the-export-attribute) .
### component 4: "stable" mangling scheme
The mangling scheme proposed in the RFC consists of two parts: a mangled item path and a hash of the signature.
#### mangled item path
For the first part of the symbol it has been decided to reuse the `v0` mangling scheme as it much less dependent on compiler internals compared to the `legacy` scheme.
The exception is disambiguators (https://doc.rust-lang.org/rustc/symbol-mangling/v0.html#disambiguator):
For example, during symbol mangling rustc uses a special index to distinguish between two impls of the same type in the same module(See `DisambiguatedDefPathData`). The calculation of this index may depend on private items, but private items should not affect the ABI. Example:
```rust
#[export]
#[repr(C)]
pub struct S<T>(pub T);
struct S1;
pub struct S2;
impl S<S1> {
extern "C" fn foo() -> i32 {
1
}
}
#[export]
impl S<S2> {
// Different symbol names can be generated for this item
// when compiling the interface and source code.
pub extern "C" fn foo() -> i32 {
2
}
}
```
In order to make disambiguation independent of the compiler version we can assign an id to each impl according to their relative order in the source code.
The second example is `StableCrateId` which is used to disambiguate different crates. `StableCrateId` consists of crate name, `-Cmetadata` arguments and compiler version. At the moment, I have decided to keep only the crate name, but a more consistent approach to crate disambiguation could be added in the future.
Actually, there are more cases where such disambiguation can be used. For instance, when mangling internal rustc symbols, but it also hasn't been investigated in detail yet.
#### hash of the signature
Exportable functions from stable dylibs can be called from safe code. In order to provide type safety, 128 bit hash with relevant type information is appended to the symbol ([description from RFC](https://github.com/m-ou-se/rfcs/blob/export/text/0000-export.md#name-mangling-and-safety)). For now, it includes:
- hash of the type name for primitive types
- for ADT types with public fields the implementation follows [this](https://github.com/m-ou-se/rfcs/blob/export/text/0000-export.md#types-with-public-fields) rules
`#[export(unsafe_stable_abi = "hash")]` syntax for ADT types with private fields is not yet implemented.
Type safety is a subtle thing here. I used the approach from RFC, but there is the ongoing research project about it. [https://rust-lang.github.io/rust-project-goals/2025h1/safe-linking.html](https://rust-lang.github.io/rust-project-goals/2025h1/safe-linking.html)
### Unresolved questions
Interfaces:
1. Move the interface generator to HIR and add an exportable items filter.
2. Compatibility of auto-generated interfaces and macro hygiene.
3. There is an open issue with interface files compilation: https://github.com/rust-lang/rust/pull/134767#issuecomment-2736471828
4. Put an interface into a dylib.
Mangling scheme:
1. Which information is required to ensure type safety and how should it be encoded? ([https://rust-lang.github.io/rust-project-goals/2025h1/safe-linking.html](https://rust-lang.github.io/rust-project-goals/2025h1/safe-linking.html))
2. Determine all other possible cases, where path disambiguation is used. Make it compiler independent.
We also need a semi-stable API to represent types. For example, the order of fields in the `VariantDef` must be stable. Or a semi-stable representation for AST, which ensures that the order of the items in the code is preserved.
There are some others, mentioned in the proposal.
Rollup of 6 pull requests
Successful merges:
- #137280 (stabilize ptr::swap_nonoverlapping in const)
- #140457 (Use target-cpu=z13 on s390x codegen const vector test)
- #140619 (Small adjustments to `check_attribute_safety` to make the logic more obvious)
- #140625 (Suggest `retain_mut` over `retain` as `Vec::extract_if` alternative)
- #140627 (Allow linking rustc and rustdoc against the same single tracing crate)
- #140630 (Async drop source info fix for proxy-drop-coroutine)
r? `@ghost`
`@rustbot` modify labels: rollup
Use target-cpu=z13 on s390x codegen const vector test
The default s390x cpu(z10) does not have vector support. Setting target-cpu at least to z13 enables vectorisation for s390x architecture and makes the test pass.
stabilize ptr::swap_nonoverlapping in const
Closes https://github.com/rust-lang/rust/issues/133668
The blocking issue mentioned there is resolved by documentation. We may in the future actually support such code, but that is blocked on https://github.com/rust-lang/const-eval/issues/72 which is non-trivial to implement. Meanwhile, this completes stabilization of all `const fn` in `ptr`. :)
Here's a version of the problematic example to play around with:
https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=6c390452379fb593e109b8f8ee854d2a
Should be FCP'd with both `@rust-lang/libs-api` and `@rust-lang/lang` since `swap_nonoverlapping` is documented to work as an "untyped" operation but due to the limitation mentioned above, that's not entirely true during const evaluation. I expect this limitation will only be hit in niche corner cases, so the benefits of having this function work most of the time outweigh the downsides of users running into this problem. (Note that unsafe code could already hit this limitation before this PR by doing cursed pointer casts, but having it hidden inside `swap_nonoverlapping` feels a bit different.)
Matthias Krüger
bors
omahs
Eric Huss
Tomasz Miąsko
Jakub Beránek
Guillaume Gomez
Ralf Jung
Trevor Gross