I.e. the following situation:
```
fn foo() {
mod bar {
fn qux() {
// Prelude path here (e.g. macro use prelude or extern prelude).
}
}
}
```
Those were previously unresolved, because, in order to support `self` and `super` properly, since #15148 we do not ascend block paths when there is a module in between, but only crate def maps register preludes, not block def maps, and we can't change this because block def map prelude can always be overridden by another block. E.g.
```
fn foo() {
struct WithTheSameNameAsPreludeItem;
{
WithTheSameNameAsPreludeItem
}
}
```
Here `WithTheSameNameAsPreludeItem` refer to the item from the top block, but if we would register prelude items in each block the child block would overwrite it incorrectly.
rustc_target: Add pauth-lr aarch64 target feature
Add the pauth-lr target feature, corresponding to aarch64 FEAT_PAuth_LR. This feature has been added in LLVM 19.
It is currently not supported by the Linux hwcap and so we cannot add runtime feature detection for it at this time.
r? `@Amanieu`
(Big performance change) Do not run lints that cannot emit
Before this change, adding a lint was a difficult matter because it always had some overhead involved. This was because all lints would run, no matter their default level, or if the user had `#![allow]`ed them. This PR changes that. This change would improve both the Rust lint infrastructure and Clippy, but Clippy will see the most benefit, as it has about 900 registered lints (and growing!)
So yeah, with this little patch we filter all lints pre-linting, and remove any lint that is either:
- Manually `#![allow]`ed in the whole crate,
- Allowed in the command line, or
- Not manually enabled with `#[warn]` or similar, and its default level is `Allow`
As some lints **need** to run, this PR also adds **loadbearing lints**. On a lint declaration, you can use the ``@eval_always` = true` marker to label it as loadbearing. A loadbearing lint will never be filtered (it will always run)
Fixes#106983
Run the full stage 2 `run-make` test suite in `x86_64-gnu-debug`
Run the full `run-make` test suite in the `x86_64-gnu-debug` CI job. This is currently the *only* CI job where `//@ needs-force-clang-based-test` will be satisfied, so some `run-make` tests will literally never be run otherwise. Before this PR, the CI job only ran `run-make` tests which contains the substring `clang` in its test name, which is both (1) a footgun because it's very easy to forget and (2) it masks tests that would otherwise fail (even failing to compile) because the test is skipped if doesn't have a `clang` in its test name.
With the environment of `x86_64-gnu-debug`, two `run-make` tests failed before this PR:
1. `tests/run-make/issue-84395-lto-embed-bitcode/rmake.rs`: this was broken for a long time because `objcopy` in llvm bin tools was renamed to `llvm-objcopy`. This test was converted into a rmake.rs test, rather straight forward.
2. `tests/run-make/cross-lang-lto-riscv-abi/rmake.rs`: this was broken for a long time and never worked. The old version inspected human-readable output of `llvm-readobj --file-header` looking for substring `EF_RISCV_FLOAT_ABI_DOUBLE`, but the human-readable output will only contain something like `Flags: 0x5, RVC, double-float ABI`, hence it will never match. This test was fixed by instead using the `object` crate to actually decode the ELF headers looking for the specific `e_flags` based on reading the RISCV ELF psABI docs.
This PR is best reviewed commit-by-commit, two commits setup the support library for functionality and two commits are for each of the failing `run-make` tests.
I had to bump the `x86_64-gnu-debug` job to be ran with a runner with larger disk space.
Part of #132034.
try-job: x86_64-gnu-debug
Emit future-incompatibility lint when calling/declaring functions with vectors that require missing target feature
On some architectures, vector types may have a different ABI depending on whether the relevant target features are enabled. (The ABI when the feature is disabled is often not specified, but LLVM implements some de-facto ABI.)
As discussed in https://github.com/rust-lang/lang-team/issues/235, this turns out to very easily lead to unsound code.
This commit makes it a post-monomorphization error to declare or call functions using those vector types in a context in which the corresponding target features are disabled, if using an ABI for which the difference is relevant. This ensures that these functions are always called with a consistent ABI.
See the [nomination comment](https://github.com/rust-lang/rust/pull/127731#issuecomment-2288558187) for more discussion.
r? RalfJung
Part of https://github.com/rust-lang/rust/issues/116558
Thanks to the observation (supported by counting) that the vast majority paths have neither generics no type anchors, and thanks to a new datastructure `ThinVecWithHeader` that is essentially `(T, Box<[U]>)` but with the size of a single pointer, we are able to reach this feat.
This (together with `ThinVecWithHeader`) makes the possibility to shrink `TypeRef`, because most types are paths.
Add a separate markdown file containing the settings.json snippet from
the "Useful Setup Tips". This fixes the rendering and also makes the
text selectable.
Also use double-backticks for `code` rendering.
So that given a `TypeRef` we will be able to trace it back to source code.
This is necessary to be able to provide diagnostics for lowering to chalk tys, since the input to that is `TypeRef`.
This means that `TypeRef`s now have an identity, which means storing them in arena and not interning them, which is an unfortunate (but necessary) loss but also a pretty massive change. Luckily, because of the separation layer we have for IDE and HIR, this change never crosses the IDE boundary.
Remove the `Arc` rt::init allocation for thread info
Removes an allocation pre-main by just not storing anything in std:🧵:Thread for the main thread.
- The thread name can just be a hard coded literal, as was done in #123433.
- Storing ThreadId and Parker in a static that is initialized once at startup. This uses SyncUnsafeCell and MaybeUninit as this is quite performance critical and we don't need synchronization or to store a tag value and possibly leave in a panic.
