Stabilize `#![feature(target_feature_11)]`
## Stabilization report
### Summary
Allows for safe functions to be marked with `#[target_feature]` attributes.
Functions marked with `#[target_feature]` are generally considered as unsafe functions: they are unsafe to call, cannot be assigned to safe function pointers, and don't implement the `Fn*` traits.
However, calling them from other `#[target_feature]` functions with a superset of features is safe.
```rust
// Demonstration function
#[target_feature(enable = "avx2")]
fn avx2() {}
fn foo() {
// Calling `avx2` here is unsafe, as we must ensure
// that AVX is available first.
unsafe {
avx2();
}
}
#[target_feature(enable = "avx2")]
fn bar() {
// Calling `avx2` here is safe.
avx2();
}
```
### Test cases
Tests for this feature can be found in [`src/test/ui/rfcs/rfc-2396-target_feature-11/`](b67ba9ba20/src/test/ui/rfcs/rfc-2396-target_feature-11/).
### Edge cases
- https://github.com/rust-lang/rust/issues/73631
Closures defined inside functions marked with `#[target_feature]` inherit the target features of their parent function. They can still be assigned to safe function pointers and implement the appropriate `Fn*` traits.
```rust
#[target_feature(enable = "avx2")]
fn qux() {
let my_closure = || avx2(); // this call to `avx2` is safe
let f: fn() = my_closure;
}
```
This means that in order to call a function with `#[target_feature]`, you must show that the target-feature is available while the function executes *and* for as long as whatever may escape from that function lives.
### Documentation
- Reference: https://github.com/rust-lang/reference/pull/1181
---
cc tracking issue #69098
r? `@ghost`
Avoid invoking typeck from borrowck
This PR attempts to reduce direct dependencies between typeck and MIR-related queries. The goal is to have all the information transit either through THIR or through dedicated queries that avoid depending on the whole `TypeckResults`.
In a first commit, we store the type information that MIR building requires into THIR. This avoids edges between mir_built and typeck.
In the second and third commit, we wrap informations around closures (upvars, kind origin and user-provided signature) to avoid borrowck depending on typeck information.
There should be a single remaining borrowck -> typeck edge in the good path, due to inline consts.
Rollup of 8 pull requests
Successful merges:
- #104265 (Move IpAddr, SocketAddr and V4+V6 related types to `core`)
- #107110 ([stdio][windows] Use MBTWC and WCTMB)
- #108308 (Allow building serde and serde_derive in parallel)
- #108363 (Move the unused extern crate check back to the resolver.)
- #108519 (Bages for easy access links to Rust community)
- #108522 (Commit some new solver tests)
- #108523 (Avoid `&str` to `String` conversions)
- #108533 (diagnostics: avoid querying `associated_item` in the resolver)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Move THIR printing to rustc_mir_build.
https://github.com/rust-lang/rust/pull/107451 increased the compilation time of `rustc_middle` by 10% = 3s.
As https://github.com/rust-lang/rust/pull/107006 adds quite a lot of code to rustc_middle, I suspect it to be the cause.
This PR moves the THIR printing code to `rustc_mir_build`, where the query provider lives, in order to benefit from higher parallelism when compiling rustc.
MIR-Validate StorageLive.
`StorageLive` statements on a local which already has storage is banned by miri.
This check is easy enough, and can detect bugs in MIR opts.
Unify validity checks into a single query
Previously, there were two queries to check whether a type allows the 0x01 or zeroed bitpattern.
I am planning on adding a further initness to check in #100423, truly uninit for MaybeUninit, which would make this three queries. This seems overkill for such a small feature, so this PR unifies them into one.
I am not entirely happy with the naming and key type and open for improvements.
r? oli-obk
Don't project specializable RPITIT projection
This effective rejects specialization + RPITIT/AFIT (usages of `impl Trait` in traits) because the implementation is significantly complicated over making regular "default" trait method bodies work.
I have another PR that experimentally fixes all this, but the code may not be worth investing in.
Emit the enum discriminant separately for the Encodable macro
This changes the `Encodable` proc macro to first emit the discriminant with a separate `match` statement, then emit the fields. LLVM can optimize down the first `match` to just a read of the enum discriminant. This avoids generating a `emit_usize` call per variant and enums with no fields now optimize down to just a single `emit_usize` call.
The no variant case is special cased to avoid warnings about unreachable code.
<table><tr><td rowspan="2">Benchmark</td><td colspan="1"><b>Before</b></th><td colspan="2"><b>After</b></th></tr><tr><td align="right">Time</td><td align="right">Time</td><td align="right">%</th></tr><tr><td>🟣 <b>clap</b>:check:unchanged</td><td align="right">0.4676s</td><td align="right">0.4640s</td><td align="right"> -0.78%</td></tr><tr><td>🟣 <b>hyper</b>:check:unchanged</td><td align="right">0.1348s</td><td align="right">0.1338s</td><td align="right"> -0.75%</td></tr><tr><td>🟣 <b>regex</b>:check:unchanged</td><td align="right">0.3370s</td><td align="right">0.3352s</td><td align="right"> -0.54%</td></tr><tr><td>🟣 <b>syn</b>:check:unchanged</td><td align="right">0.6326s</td><td align="right">0.6281s</td><td align="right"> -0.71%</td></tr><tr><td>🟣 <b>syntex_syntax</b>:check:unchanged</td><td align="right">1.8561s</td><td align="right">1.8589s</td><td align="right"> 0.15%</td></tr><tr><td>Total</td><td align="right">3.4282s</td><td align="right">3.4200s</td><td align="right"> -0.24%</td></tr><tr><td>Summary</td><td align="right">1.0000s</td><td align="right">0.9947s</td><td align="right"> -0.53%</td></tr></table>
Upgrade to ena-0.14.1.
It avoids some inlining within its `inlined_probe_value` function, which seems to result in better codegen for the very large `process_obligations` function within rustc. It might also help with reducing the bimodal perf results we see for the `keccak` and `cranelift-codegen-0.82.1` benchmarks.
r? `@ghost`
Remove `from` lang item
It was probably a leftover from the old `?` desugaring but anyways, it's unused now except for clippy, which can just use a diagnostics item.
statically guarantee that current error codes are documented
Closes#61137 (that's right!)
Pretty simple refactor (often just a change from `Result<Option<&str>>` to `Result<&str>`)
r? `@GuillaumeGomez` (could you specially look at 53044158eff0d64673a6100f701c57b484232aca? I believe you wrote that in the first place, just want to make sure you're happy with the change)
rustc_infer: Consolidate obligation elaboration de-duplication
# Explanation
The obligations `Elaborator` is doing de-duplication of obligations in 3 different locations. 1 off which has a comment.
This PR consolidates the functionality and comment to a single function.
Replace parse_[sth]_expr with parse_expr_[sth] function names
This resolves an inconsistency in naming style for functions on the parser, where:
* functions parsing specific kinds of items are named `parse_item_[sth]` and
* functions parsing specific kinds of *expressions* are named `parse_[sth]_expr`
favoring the style used by functions for items. There are multiple advantages of that style:
* functions of both categories are collected in the same place in the [rustdoc output](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_parse/parser/struct.Parser.html).
* it helps with autocompletion, as you can narrow down your search for a function to those about expressions.
* it mirrors rust's path syntax where less specific things come first, then it gets more specific, i.e. `std::collections::hash_map::Entry`.
The disadvantage is that it doesn't "read like a sentence" any more. But I think the advantages weigh more greatly.
This change was mostly application of this command:
```
sed -i -E 's/(fn |\.)parse_([[:alnum:]_]+)_expr/\1parse_expr_\2/' compiler/rustc_parse/src/parser/*.rs
```
Plus very minor fixes outside of `rustc_parse`, and an invocation of `x fmt`.
Add `ErrorGuaranteed` to `hir::{Expr,Ty}Kind::Err` variants
First step in making the `Err` variants of `ExprKind` and `TyKind` require an `ErrorGuaranteed` during parsing. Making the corresponding AST versions require `ErrorGuaranteed` is a bit harder, whereas it was pretty easy to do this for HIR, so let's do that first.
The only weird thing about this PR is that `ErrorGuaranteed` is moved to `rustc_span`. This is *certainly* not the right place to put it, but `rustc_hir` cannot depend on `rustc_error` because the latter already depends on the former. Should I just pull out some of the error machinery from `rustc_error` into an even more minimal crate that `rustc_hir` can depend on? Advice would be appreciated.
Treat `str` as containing `[u8]` for auto trait purposes
Wanted to gauge ``@rust-lang/lang`` and ``@rust-lang/types`` teams' thoughts on treating `str` as "containing" a `[u8]` slice for auto-trait purposes.
``@dtolnay`` brought this up in https://github.com/rust-lang/rust/issues/13231#issuecomment-1399386472 as a blocker for future `str` type librarification, and I think it's both a valid concern and very easy to fix. I'm interested in actually doing that `str` type librarification (#107939), but this probably should be considered in the mean time regardless of that PR.
r? types for the impl, though this definitely needs an FCP.
Rollup of 8 pull requests
Successful merges:
- #107062 (Do some cleanup of doc/index.md)
- #107890 (Lint against `Iterator::map` receiving a callable that returns `()`)
- #108431 (Add regression test for #107918)
- #108432 (test: drop unused deps)
- #108436 (make "proc macro panicked" translatable)
- #108444 (docs/test: add UI test and docs for `E0476`)
- #108449 (Do not lint ineffective unstable trait impl for unresolved trait)
- #108456 (Complete migrating `ast_passes` to derive diagnostics)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
docs/test: add UI test and docs for `E0476`
Final undocumented error code. Not entirely sure about wording in the docs.
Part of https://github.com/rust-lang/rust/issues/61137.
r? ```@compiler-errors```
cc ```@compiler-errors```
