Include better context for "already exists" error in compiletest
I encountered the following error from `x.py test tests/ui` today.
```console
---- [ui] tests/ui/impl-trait/multiple-lifetimes/multiple-lifetimes.rs stdout ----
thread '[ui] tests/ui/impl-trait/multiple-lifetimes/multiple-lifetimes.rs' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 17, kind: AlreadyExists, message: "File exists" }', src/tools/compiletest/src/runtest.rs:134:43
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
I found it impossible to unblock myself without knowing which directory it was stuck on.
Error message after this PR:
```console
---- [ui] tests/ui/impl-trait/multiple-lifetimes/multiple-lifetimes.rs stdout ----
thread '[ui] tests/ui/impl-trait/multiple-lifetimes/multiple-lifetimes.rs' panicked at 'called `Result::unwrap()` on an `Err` value: failed to create output base directory /git/rust/build/x86_64-unknown-linux-gnu/test/ui/impl-trait/multiple-lifetimes/multiple-lifetimes
Caused by:
File exists (os error 17)', src/tools/compiletest/src/runtest.rs:139:10
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
Now I was able to run `rm build/x86_64-unknown-linux-gnu/test/ui/impl-trait/multiple-lifetimes/multiple-lifetimes` and unblock myself.
Seems to be related to #109509 moving *tests/ui/impl-trait/multiple-lifetimes.rs* to *tests/ui/impl-trait/multiple-lifetimes/multiple-lifetimes.rs*.
add examples of port 0 binding behavior
Was trying to find the method to specify the IP address but not the port, and there wasn't information easily accessible about it in the `TcpListener` or `SocketAddr`. Adding examples to `TcpListener` and `UdpSocket` for clarity.
Specialize ToString implementation for fmt::Arguments
Generates far fewer instructions by formatting into a String with `fmt::format` directly instead of going through the `fmt::Display` impl. This change is insta-stable.
Update serde in workspace and non-synced dependencies
The main workspace, bootstrap, cargo, miri, and rust-analyzer all lock serde to different versions. It's preferable to share the same version where possible, so update it.
Rustfmt is synced from another repository and has its own Cargo.lock, but since it's added to the overall workspace it should respect the version here.
Cargo is already at the latest version. Miri and rust-analyzer would require upstream updates.
Support RISC-V unaligned-scalar-mem target feature
This adds `unaligned-scalar-mem` as an allowed RISC-V target feature. Some RISC-V cores support unaligned access to memory without trapping. On such cores, the compiler could significantly improve code-size and performance when using functions like core::ptr::read_unaligned<u32> by emitting a single load or store instruction with an unaligned address, rather than a long sequence of byte load/store/bitmanip instructions.
Enabling the `unaligned-scalar-mem` target feature allows LLVM to do this optimization.
Fixes#110883
don't remove `dbg!` in arbitrary expressions
Fixes#9914
The `dbg_macro` lint replaces empty `dbg!` invocations with the empty string in its suggestion, which is not always valid code in certain contexts (e.g. `let _ = dbg!();` becomes `let _ = ;`). This PR changes it to `()`, which should always be valid where `dbg!()` is valid (`dbg!()` with no arguments evaluates to `()`).
It also special-cases "standalone" `dbg!();` expression statements, where it will suggest removing the whole statement entirely like it did before.
changelog: [`dbg_macro`]: don't remove `dbg!()` in arbitrary expressions as it sometimes results in syntax errors
Before:
```
= note: delayed at 0: <rustc_errors::HandlerInner>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1335:29
1: <rustc_errors::Handler>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1124:9
...
```
After:
```
= note: delayed at compiler/rustc_parse/src/parser/diagnostics.rs:2158:28
0: <rustc_errors::HandlerInner>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1335:29
1: <rustc_errors::Handler>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1124:9
```
This both makes the relevant frame easier to find without having to dig
through diagnostic internals, and avoids the weird-looking formatting
for the first frame.
Remove unnecessary `clone` from `needless_collect` example
The example for [clippy::needless_collect](https://rust-lang.github.io/rust-clippy/master/#needless_collect) is written as follows:
```rust
let len = iterator.clone().collect::<Vec<_>>().len();
// should be
let len = iterator.count();
```
With this change, the unnecessary `clone()` is removed and the the standard
### Example
```rust
// original
```
Use instead:
```rust
// improved
```
structure is followed.
Discussion: https://github.com/rust-lang/rust-clippy/discussions/10784#discussion-5198885
changelog: [`needless_collect`]: Cleaned up the example in the lint documentation.
fix [`invalid_regex`] not recognizing new syntax introduced after regex-1.8.0
fixes: #10680
---
changelog: fix [`invalid_regex`] not recognizing new syntax introduced after regex-1.8.0
bump up `regex-syntax` dependency version to 0.7.0
Remove the ThinLTO CU hack
This reverts #46722, commit e0ab5d5feb4eb2d8af11b8dd9446c2b45fada8af.
Since #111167, commit 10b69dde3fd15334ea2382d2dc9e9a261de1afaf, we are
generating DWARF subprograms in a way that is meant to be more compatible
with LLVM's expectations, so hopefully we don't need this workaround
rewriting CUs anymore.
Fix: Some suggestions generated by the option_if_let_else lint did not compile
This addresses a bug in Clippy where the fix suggestend by the `option_if_let_else` lint would not compile for `Result`s which have an impure expression in the `else` branch.
---
changelog: [`option_if_let_else`]: Fixed incorrect suggestion for `Result`s
[#10337](https://github.com/rust-lang/rust-clippy/pull/10337)
<!-- changelog_checked -->
Fixes#10335.
Fixes#111510 and complements #106547 by adding support for encoding
type parameters and also by transforming trait objects' traits into
their identities before emitting type checks.
Stop turning transmutes into discriminant reads in mir-opt
Partially reverts #109612, as after #109993 these aren't actually equivalent any more, and I'm no longer confident this was ever an improvement in the first place.
Having this "simplification" meant that similar-looking code actually did somewhat different things. For example,
```rust
pub unsafe fn demo1(x: std::cmp::Ordering) -> u8 {
std::mem::transmute(x)
}
pub unsafe fn demo2(x: std::cmp::Ordering) -> i8 {
std::mem::transmute(x)
}
```
in nightly today is generating <https://rust.godbolt.org/z/dPK58zW18>
```llvm
define noundef i8 `@_ZN7example5demo117h341ef313673d2ee6E(i8` noundef %x) unnamed_addr #0 {
%0 = icmp uge i8 %x, -1
%1 = icmp ule i8 %x, 1
%2 = or i1 %0, %1
call void `@llvm.assume(i1` %2)
ret i8 %x
}
define noundef i8 `@_ZN7example5demo217h5ad29f361a3f5700E(i8` noundef %0) unnamed_addr #0 {
%x = alloca i8, align 1
store i8 %0, ptr %x, align 1
%1 = load i8, ptr %x, align 1, !range !2, !noundef !3
ret i8 %1
}
```
Which feels too different when the original code is essentially identical.
---
Aside: that example is different *after* optimizations too:
```llvm
define noundef i8 `@_ZN7example5demo117h341ef313673d2ee6E(i8` noundef returned %x) unnamed_addr #0 {
%0 = add i8 %x, 1
%1 = icmp ult i8 %0, 3
tail call void `@llvm.assume(i1` %1)
ret i8 %x
}
define noundef i8 `@_ZN7example5demo217h5ad29f361a3f5700E(i8` noundef returned %0) unnamed_addr #1 {
ret i8 %0
}
```
so turning the `Transmute` into a `Discriminant` was arguably just making things worse, so leaving it alone instead -- and thus having less code in rustc -- seems clearly better.
Add a conversion from `&mut T` to `&mut UnsafeCell<T>`
Provides a safe way of downgrading an exclusive reference into an alias-able `&UnsafeCell<T>` reference.
ACP: https://github.com/rust-lang/libs-team/issues/198.
