Commit graph

17621 commits

Author SHA1 Message Date
The Miri Cronjob Bot
65e76849ac Merge from rustc 2025-04-25 05:01:33 +00:00
The Miri Cronjob Bot
37049558e4 Preparing for merge from rustc 2025-04-25 04:54:29 +00:00
Matthias Krüger
a01655298a
Rollup merge of #140191 - Kobzol:remove-git-repository-from-git-config, r=jieyouxu
Remove git repository from git config

It is no longer needed after https://github.com/rust-lang/rust/pull/138591. We could even remove the `nightly_branch` field, but it still has one usage.

r? ``@jieyouxu``
2025-04-24 17:19:47 +02:00
Matthias Krüger
cea6ba7a06
Rollup merge of #140172 - bjoernager:const-float-algebraic, r=RalfJung
Make algebraic functions into `const fn` items.

Tracking issue: #136469

This PR makes the algebraic intrinsics and the unstable, algebraic functions of `f16`, `f32`, `f64`, and `f128` into `const fn` items:

```rust
impl f16 {
    pub const fn algebraic_add(self, rhs: f16) -> f16;
    pub const fn algebraic_sub(self, rhs: f16) -> f16;
    pub const fn algebraic_mul(self, rhs: f16) -> f16;
    pub const fn algebraic_div(self, rhs: f16) -> f16;
    pub const fn algebraic_rem(self, rhs: f16) -> f16;
}

impl f32 {
    pub const fn algebraic_add(self, rhs: f32) -> f32;
    pub const fn algebraic_sub(self, rhs: f32) -> f32;
    pub const fn algebraic_mul(self, rhs: f32) -> f32;
    pub const fn algebraic_div(self, rhs: f32) -> f32;
    pub const fn algebraic_rem(self, rhs: f32) -> f32;
}

impl f64 {
    pub const fn algebraic_add(self, rhs: f64) -> f64;
    pub const fn algebraic_sub(self, rhs: f64) -> f64;
    pub const fn algebraic_mul(self, rhs: f64) -> f64;
    pub const fn algebraic_div(self, rhs: f64) -> f64;
    pub const fn algebraic_rem(self, rhs: f64) -> f64;
}

impl f128 {
    pub const fn algebraic_add(self, rhs: f128) -> f128;
    pub const fn algebraic_sub(self, rhs: f128) -> f128;
    pub const fn algebraic_mul(self, rhs: f128) -> f128;
    pub const fn algebraic_div(self, rhs: f128) -> f128;
    pub const fn algebraic_rem(self, rhs: f128) -> f128;
}

// core::intrinsics

pub const fn fadd_algebraic<T: Copy>(a: T, b: T) -> T;
pub const fn fsub_algebraic<T: Copy>(a: T, b: T) -> T;
pub const fn fmul_algebraic<T: Copy>(a: T, b: T) -> T;
pub const fn fdiv_algebraic<T: Copy>(a: T, b: T) -> T;
pub const fn frem_algebraic<T: Copy>(a: T, b: T) -> T;
```

This PR does not preserve the initial behaviour of these functions yielding non-deterministic output under Miri; it is most likely desired to reimplement this behaviour at some point.
2025-04-24 17:19:46 +02:00
Matthias Krüger
53afa97eb7
Rollup merge of #136083 - bend-n:⃤⃤, r=lcnr
Suggest {to,from}_ne_bytes for transmutations between arrays and integers, etc

implements #136067

Rust has helper methods for many kinds of safe transmutes, for example integer<->bytes. This is a lint against using transmute for these cases.

```rs
fn bytes_at_home(x: [u8; 4]) -> u32 {
   transmute(x)
}

// other examples
transmute::<[u8; 2], u16>();
transmute::<[u8; 8], f64>();
transmute::<u32, [u8; 4]>();
transmute::<char, u32>();
transmute::<u32, char>();
```
It would be handy to suggest `u32::from_ne_bytes(x)`.
This is implemented for `[u8; _]` -> `{float int}`

This also implements the cases:
`fXX` <-> `uXX` = `{from_bits, to_bits}`
`uXX` -> `iXX` via `cast_unsigned` and `cast_signed`
{`char` -> `u32`, `bool` -> `n8`} via `from`
`u32` -> `char` via `from_u32_unchecked` (note: notes `from_u32().unwrap()`) (contested)
`u8` -> `bool` via `==` (debatable)

---
try-job: aarch64-gnu
try-job: test-various
2025-04-24 17:19:42 +02:00
bors
3c877f6a47 Auto merge of #140245 - matthiaskrgr:rollup-e0fwsfv, r=matthiaskrgr
Rollup of 8 pull requests

Successful merges:

 - #139261 (mitigate MSVC alignment issue on x86-32)
 - #140075 (Mention average in midpoint documentations)
 - #140184 (Update doc of cygwin target)
 - #140186 (Rename `compute_x` methods)
 - #140194 (minicore: Have `//@ add-core-stubs` also imply `-Cforce-unwind-tables=yes`)
 - #140195 (triagebot: label minicore changes w/ `A-test-infra-minicore` and ping jieyouxu on changes)
 - #140214 (Remove comment about handling non-global where bounds with corresponding projection)
 - #140228 (Revert overzealous parse recovery for single colons in paths)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-04-24 12:06:16 +00:00
Matthias Krüger
a90f31e319
Rollup merge of #140194 - jieyouxu:minicore-force-unwind-tables, r=bjorn3
minicore: Have `//@ add-core-stubs` also imply `-Cforce-unwind-tables=yes`

To preserve CFI directives in assembly tests, as `//@ add-core-stubs` already imply `-C panic=abort`.

This is a blocker for https://github.com/rust-lang/rust/pull/140037#issuecomment-2816665358.

cc ```@RalfJung```
r? ```@bjorn3```
2025-04-24 11:40:42 +02:00
Ralf Jung
f2bbc1bf06 clippy 2025-04-24 11:03:24 +02:00
Ralf Jung
f1b6b85f08 CI: print message when skipping PR 2025-04-24 10:59:04 +02:00
Ralf Jung
6496974882 Merge from rustc 2025-04-24 10:57:54 +02:00
Boxy
bdfeb8f36b Remove weak alias terminology 2025-04-24 11:59:20 +01:00
Ralf Jung
9b491c0b3b Preparing for merge from rustc 2025-04-24 10:57:42 +02:00
bendn
c8c074288a
Suggest {to,from}_ne_bytes for transmutations between arrays and integers, etc 2025-04-24 13:14:36 +07:00
Matthias Krüger
fdaa91a0d7
Rollup merge of #134446 - tgross35:stabilize-cell_update, r=jhpratt
Stabilize the `cell_update` feature

Included API:

```rust
impl<T: Copy> Cell<T> {
    pub fn update(&self, f: impl FnOnce(T) -> T);
}
```

FCP completed once at https://github.com/rust-lang/rust/issues/50186#issuecomment-2198783432 but the signature has since changed.

Closes: https://github.com/rust-lang/rust/issues/50186
2025-04-24 08:12:56 +02:00
bors
df35ff6c35 Auto merge of #139983 - flip1995:clippy-subtree-update, r=Manishearth
Clippy subtree update

r? `@Manishearth`

Cargo.lock update due to the Clippy version bump and because Clippy moved from rinja (unmaintained) to askama.

Last sync was skipped due to the askama issue and me not getting to fixing this in time.
2025-04-23 18:23:51 +00:00
bors
be181dd75c Auto merge of #139998 - Zalathar:new-executor, r=onur-ozkan
compiletest: Use the new non-libtest executor by default

The new executor was implemented in #139660, but required a manual opt-in. This PR activates the new executor by default, but leaves the old libtest-based executor in place (temporarily) to make reverting easier if something unexpectedly goes horribly wrong.

Currently the new executor can be explicitly disabled by passing the `-N` flag to compiletest (e.g. `./x test ui -- -N`), but eventually that flag will be removed, alongside the removal of the libtest dependency. The flag is mostly there to make manual comparative testing easier if something does go wrong.

As before, there *should* be no user-visible difference between the old executor and the new executor.

---

I didn't get much of a response to my [call for testing thread on Zulip](https://rust-lang.zulipchat.com/#narrow/channel/122651-general/topic/Call.20for.20testing.3A.20New.20test.20executor.20for.20compiletest/with/512452105), and the reports I did get (along with my own usage) indicate that there aren't any problems. So I think it's reasonable to move forward with making this the default, in the hopes of being able to remove the libtest dependency relatively soon.

When the libtest dependency is removed, it should be reasonable to build compiletest against pre-built stage0 std by default, even after the stage0 redesign. (Though we should probably have at least one CI job using in-tree stage1 std instead, to guard against the possibility of the `#![feature(internal_output_capture)]` API actually changing.)
2025-04-23 12:12:31 +00:00
Jieyou Xu
e3296cdcab
compiletest: //@ add-core-stubs implies -Cforce-unwind-tables=yes
To preserve CFI directives in assembly tests.
2025-04-23 17:11:07 +08:00
Philipp Krones
e8737e3530
Clippy: Fix doc issue 2025-04-23 10:51:22 +02:00
Jakub Beránek
a4b9a1b4da Remove git_repository field from GitConfig
It is no longer needed after a recent refactoring.
2025-04-23 10:41:20 +02:00
Gabriel Bjørnager Jensen
0296f05ce5 Make algebraic intrinsics into 'const fn' items; Make algebraic functions of 'f16', 'f32', 'f64', and 'f128' into 'const fn' items; 2025-04-23 08:54:52 +02:00
The Miri Cronjob Bot
f356f2f203 Merge from rustc 2025-04-23 05:01:15 +00:00
The Miri Cronjob Bot
39ddb42627 Preparing for merge from rustc 2025-04-23 04:54:12 +00:00
bors
645d0ad2a4 Auto merge of #138591 - Kobzol:git-ci, r=Mark-Simulacrum
Refactor git change detection in bootstrap

While working on https://github.com/rust-lang/rust/pull/138395, I finally found the courage to delve into the insides of git path change detection in bootstrap, which is used (amongst other things) to detect if we should rebuilt od download `[llvm|rustc|gcc]`. I found it a bit hard to understand, and given that this code was historically quite fragile, I thought that it would be better to rebuild it from scratch.

The previous approach had a bunch of limitations:
- It separated the computation of "are there local changes?" and "what upstream SHA should we use?" even though these two things are intertwined.
- It used hacks to work around what happens on CI.
- It had special cases for CI scattered throughout the codebase, rather than centralized in one place.
- It wasn't documented enough and didn't have tests for the git behavior.

The current approach should hopefully resolve all of that. I implemented a single entrypoint called `check_path_modifications` (naming bikeshed pending, half of the time I spend on this PR was thinking about names, as it's quite tricky here..) that explicitly receives a mode of operation (in CI or outside CI), and accordingly figures out that upstream SHA that we should use for downloading artifacts and it also figures out if there are any local changes. Users of this function can then use this unified output to implement `download-ci-X` and other functionality. Notably, this change detection no longer uses `git merge-base`, which makes it easier to use and doesn't require setting up remotes.

I also added a bunch of integration tests that literally spawn a git repository on disk and then check that the function can deal with various situations (PR CI, auto/try CI, local builds).

After I built this inner layer, I used it for downloading GCC, LLVM and rustc. The latter two (and especially rustc) were using the `last_modified_commit` function before, but in all cases but one this function was actually only used to check if there are any local changes, which was IMO confusing. The LLVM handling would deserve a bit of refactoring, but that's a larger change that can be done as a follow-up.

I hope that the implementation is now clear and easy to understand, so that in combination with the tests we can have more confidence that it does what we want. I tried to include a lot of documentation in the code, so I won't be repeating the actual implementation details here, if there are any questions, I'll add the answers to the documentation too :)

The new approach explicitly supports three scenarios:
- Running on PR CI, where we have one upstream bors parent commit and one PR merge commit made by GitHub.
- Running on try/auto CI, where we have one upstream bors parent commit and one PR merge commit made by bors.
- Running locally, where we assume that we have at least one upstream bors parent commit in our git history.

I removed the handling of upstreams on CI, as I think that it shouldn't be needed and I considered it to be a hack. However, it's possible that there are other use-cases that I haven't considered, so I want to ask around if people have other situations than the three use-cases described above. If there are other such use-cases, I would like to include them in the new centralized implementation and add them to the git test suite, rather than going back to the old ways :)

In particular, the code before relied on `git merge-base`, but I don't see why we can't just lookup the most recent bors commit and assume that is a merge commit that is also upstream? I might be running into Chesterton's Fence here :)

CC `@pietroalbini` To make sure that this won't break downstream users of Rust's CI.

Best reviewed commit by commit.

Companion PRs:
- For testing beta: https://github.com/rust-lang/rust/pull/138597

r? `@onur-ozkan`

Fixes: https://github.com/rust-lang/rust/issues/101907

try-job: x86_64-gnu-aux
try-job: aarch64-gnu
try-job: dist-x86_64-apple
2025-04-23 03:10:04 +00:00
Zalathar
bf4b2a94f7 compiletest: Use the new non-libtest executor by default
Currently the new executor can be explicitly disabled by passing the `-N` flag
to compiletest (e.g. `./x test ui -- -N`), but eventually that flag will be
removed, alongside the removal of the libtest dependency.
2025-04-23 12:48:05 +10:00
Philipp Krones
52bb2bb461
Merge commit '0621446356' into clippy-subtree-update 2025-04-22 18:24:43 +02:00
Chris Denton
107f04daa8
Rollup merge of #140072 - folkertdev:miri-fn-align, r=RalfJung
handle function alignment in miri

tracking issue: https://github.com/rust-lang/rust/issues/82232
Fixes https://github.com/rust-lang/miri/issues/4282

The `#[repr(align(N))]` attribute on functions was ignored when using miri. For such a function, its address should be a multiple of `N`.

There is some further discussion in the thread [#t-compiler/const-eval > function address alignment](https://rust-lang.zulipchat.com/#narrow/channel/146212-t-compiler.2Fconst-eval/topic/function.20address.20alignment) on how `dyn Fn` should be handled. The behavior there appears to be consistent between miri and nightly, though both may be incorrect. In any case, that can be resolved separately.
2025-04-22 15:24:06 +00:00
Zalathar
f7b1e035a8 compiletest: Fix deadline bugs in new executor 2025-04-22 22:03:00 +10:00
Ralf Jung
ae3adaec6d TB: add missing interior_mutability test file 2025-04-22 11:19:57 +02:00
The Miri Cronjob Bot
daa250f912 Merge from rustc 2025-04-22 05:00:59 +00:00
The Miri Cronjob Bot
9d16f6666d Preparing for merge from rustc 2025-04-22 04:53:59 +00:00
bors
fae7785b60 Auto merge of #139897 - nnethercote:rm-OpenDelim-CloseDelim, r=petrochenkov
Remove `token::{Open,Close}Delim`

By replacing them with `{Open,Close}{Param,Brace,Bracket,Invisible}`.

PR #137902 made `ast::TokenKind` more like `lexer::TokenKind` by
replacing the compound `BinOp{,Eq}(BinOpToken)` variants with fieldless
variants `Plus`, `Minus`, `Star`, etc. This commit does a similar thing
with delimiters. It also makes `ast::TokenKind` more similar to
`parser::TokenType`.

This requires a few new methods:
- `TokenKind::is_{,open_,close_}delim()` replace various kinds of
  pattern matches.
- `Delimiter::as_{open,close}_token_kind` are used to convert
  `Delimiter` values to `TokenKind`.

Despite these additions, it's a net reduction in lines of code. This is
because e.g. `token::OpenParen` is so much shorter than
`token::OpenDelim(Delimiter::Parenthesis)` that many multi-line forms
reduce to single line forms. And many places where the number of lines
doesn't change are still easier to read, just because the names are
shorter, e.g.:
```
-   } else if self.token != token::CloseDelim(Delimiter::Brace) {
+   } else if self.token != token::CloseBrace {
```

r? `@petrochenkov`
2025-04-22 01:15:06 +00:00
bors
d6c1e454aa Auto merge of #140127 - ChrisDenton:rollup-2kye32h, r=ChrisDenton
Rollup of 11 pull requests

Successful merges:

 - #134213 (Stabilize `naked_functions`)
 - #139711 (Hermit: Unify `std::env::args` with Unix)
 - #139795 (Clarify why SGX code specifies linkage/symbol names for certain statics)
 - #140036 (Advent of `tests/ui` (misc cleanups and improvements) [4/N])
 - #140047 (remove a couple clones)
 - #140052 (Fix error when an intra doc link is trying to resolve an empty associated item)
 - #140074 (rustdoc-json: Improve test for auto-trait impls)
 - #140076 (jsondocck: Require command is at start of line)
 - #140107 (rustc-dev-guide subtree update)
 - #140111 (cleanup redundant pattern instances)
 - #140118 ({B,C}Str: minor cleanup)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-04-21 19:28:16 +00:00
Chris Denton
df9e15e69f
Rollup merge of #140076 - aDotInTheVoid:jsondocline, r=GuillaumeGomez
jsondocck: Require command is at start of line

In one place we use `///``@``` instead of `//``@`.`` The test-runner allowed it, but it probably shouldn't. Ran into by ``@lolbinarycat`` in https://github.com/rust-lang/rust/pull/132748#issuecomment-2816469322:

```
error: unknown disambiguator `?(`
##[error] --> /checkout/tests/rustdoc-json/fns/return_type_alias.rs:3:25
  |
3 | ///@ set foo = "$.index[?(``@.name=='Foo')].id"``
  |                         ^^
  |
```

Maybe it's also worth erroring on this like we added in #137103

r? ``@GuillaumeGomez``
2025-04-21 18:53:19 +00:00
Chris Denton
280aa4ab1a
Rollup merge of #140120 - ChrisDenton:mir-opt-dump-rev, r=jieyouxu
Use `output_base_dir` for `mir_dump_dir`

It just occurred to me that the problem might be due to multiple revisions using the same dump directory (and therefore deleting the other revision's dir). This fixes that by simply using the normal per-test output directory, which is revision safe.
2025-04-21 15:55:59 +00:00
Chris Denton
24bd5649b1
Rollup merge of #140009 - ShE3py:tls-abort, r=thomcc
docs(LocalKey<T>): clarify that T's Drop shouldn't panic

Clarify that should a TLS destructor panics, the process will abort.

Also, an abort may be obfuscated as the process can be terminated with `SIGSEGV` or [`STATUS_STACK_BUFFER_OVERRUN`](https://devblogs.microsoft.com/oldnewthing/20190108-00/?p=100655) (i.e., `SIGABRT` is not guaranteed), so explicitly prints that the process was aborted.

Context:
https://users.rust-lang.org/t/status-stack-buffer-overrun-on-windows-without-any-usage-of-unsafe/128417

``@rustbot`` label -T-compiler
2025-04-21 15:55:57 +00:00
Chris Denton
5e202a3c71
Use output dir for mir_dump_dir 2025-04-21 15:18:39 +00:00
bors
c8f9423028 Auto merge of #139727 - rust-lang:cargo_update, r=Mark-Simulacrum
Weekly `cargo update`

Automation to keep dependencies in `Cargo.lock` current.

The following is the output from `cargo update`:

```txt

compiler & tools dependencies:
     Locking 11 packages to latest compatible versions
    Updating bstr v1.11.3 -> v1.12.0
    Updating clap v4.5.35 -> v4.5.36
    Updating clap_builder v4.5.35 -> v4.5.36
    Updating crossbeam-channel v0.5.14 -> v0.5.15
    Updating jiff v0.2.5 -> v0.2.6
    Updating jiff-static v0.2.5 -> v0.2.6
    Updating jsonpath-rust v1.0.0 -> v1.0.1
    Updating linux-raw-sys v0.9.3 -> v0.9.4
    Updating miniz_oxide v0.8.7 -> v0.8.8
    Updating self_cell v1.1.0 -> v1.2.0
    Updating winnow v0.7.4 -> v0.7.6
note: pass `--verbose` to see 38 unchanged dependencies behind latest

library dependencies:
     Locking 1 package to latest compatible version
    Updating miniz_oxide v0.8.7 -> v0.8.8
note: pass `--verbose` to see 4 unchanged dependencies behind latest

rustbook dependencies:
     Locking 9 packages to latest compatible versions
    Updating bstr v1.11.3 -> v1.12.0
    Updating cc v1.2.18 -> v1.2.19
    Updating clap v4.5.35 -> v4.5.36
    Updating clap_builder v4.5.35 -> v4.5.36
    Updating jiff v0.2.5 -> v0.2.6
    Updating jiff-static v0.2.5 -> v0.2.6
    Updating linux-raw-sys v0.9.3 -> v0.9.4
    Updating miniz_oxide v0.8.7 -> v0.8.8
    Updating winnow v0.7.4 -> v0.7.6
```
2025-04-21 12:07:02 +00:00
Nicholas Nethercote
bf8ce32558 Remove token::{Open,Close}Delim.
By replacing them with `{Open,Close}{Param,Brace,Bracket,Invisible}`.

PR #137902 made `ast::TokenKind` more like `lexer::TokenKind` by
replacing the compound `BinOp{,Eq}(BinOpToken)` variants with fieldless
variants `Plus`, `Minus`, `Star`, etc. This commit does a similar thing
with delimiters. It also makes `ast::TokenKind` more similar to
`parser::TokenType`.

This requires a few new methods:
- `TokenKind::is_{,open_,close_}delim()` replace various kinds of
  pattern matches.
- `Delimiter::as_{open,close}_token_kind` are used to convert
  `Delimiter` values to `TokenKind`.

Despite these additions, it's a net reduction in lines of code. This is
because e.g. `token::OpenParen` is so much shorter than
`token::OpenDelim(Delimiter::Parenthesis)` that many multi-line forms
reduce to single line forms. And many places where the number of lines
doesn't change are still easier to read, just because the names are
shorter, e.g.:
```
-   } else if self.token != token::CloseDelim(Delimiter::Brace) {
+   } else if self.token != token::CloseBrace {
```
2025-04-21 07:35:56 +10:00
Chris Denton
d15c603173
Rollup merge of #137953 - RalfJung:simd-intrinsic-masks, r=WaffleLapkin
simd intrinsics with mask: accept unsigned integer masks, and fix some of the errors

It's not clear at all why the mask would have to be signed, it is anyway interpreted bitwise. The backend should just make sure that works no matter the surface-level type; our LLVM backend already does this correctly. The note of "the mask may be widened, which only has the correct behavior for signed integers" explains... nothing? Why can't the code do the widening correctly? If necessary, just cast to the signed type first...

Also while we are at it, fix the errors. For simd_masked_load/store, the errors talked about the "third argument" but they meant the first argument (the mask is the first argument there). They also used the wrong type for `expected_element`.

I have extremely low confidence in the GCC part of this PR.

See [discussion on Zulip](https://rust-lang.zulipchat.com/#narrow/channel/257879-project-portable-simd/topic/On.20the.20sign.20of.20masks)
2025-04-20 13:02:48 +00:00
Alona Enraght-Moony
fd4a093a4e jsondocck: Require command is at start of line 2025-04-20 11:37:00 +00:00
Jakub Beránek
fbca453d7d Fix compiletest and doc comment 2025-04-20 13:14:08 +02:00
Folkert de Vries
2d21c14015
respect repr(align(N)) on functions in miri 2025-04-20 13:08:53 +02:00
Ralf Jung
566dfd1a0d simd intrinsics with mask: accept unsigned integer masks 2025-04-20 12:25:27 +02:00
Jakub Beránek
64795ecb87 Remove setup-upstream-remote.sh and upstream handling.
It shouldn't be needed anymore.
2025-04-20 09:13:56 +02:00
The Miri Cronjob Bot
669d51106f Merge from rustc 2025-04-20 04:59:54 +00:00
The Miri Cronjob Bot
32fe60bc57 Preparing for merge from rustc 2025-04-20 04:52:36 +00:00
bors
49e5e4e3a5 Auto merge of #140043 - ChrisDenton:rollup-vwf0s9j, r=ChrisDenton
Rollup of 8 pull requests

Successful merges:

 - #138934 (support config extensions)
 - #139091 (Rewrite on_unimplemented format string parser.)
 - #139753 (Make `#[naked]` an unsafe attribute)
 - #139762 (Don't assemble non-env/bound candidates if projection is rigid)
 - #139834 (Don't canonicalize crate paths)
 - #139868 (Move `pal::env` to `std::sys::env_consts`)
 - #139978 (Add citool command for generating a test dashboard)
 - #139995 (Clean UI tests 4 of n)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-04-20 02:08:02 +00:00
Chris Denton
5d2375f789
Rollup merge of #139042 - compiler-errors:do-not-optimize-switchint, r=saethlin
Do not remove trivial `SwitchInt` in analysis MIR

This PR ensures that we don't prematurely remove trivial `SwitchInt` terminators which affects both the borrow-checking and runtime semantics (i.e. UB) of the code. Previously the `SimplifyCfg` optimization was removing `SwitchInt` terminators when they was "trivial", i.e. when all arms branched to the same basic block, even if that `SwitchInt` terminator had the side-effect of reading an operand which (for example) may not be initialized or may point to an invalid place in memory.

This behavior is unlike all other optimizations, which are only applied after "analysis" (i.e. borrow-checking) is finished, and which Miri disables to make sure the compiler doesn't silently remove UB.

Fixing this code "breaks" (i.e. unmasks) code that used to borrow-check but no longer does, like:

```rust
fn foo() {
    let x;
    let (0 | _) = x;
}
```

This match expression should perform a read because `_` does not shadow the `0` literal pattern, and the compiler should have to read the match scrutinee to compare it to 0. I've checked that this behavior does not actually manifest in practice via a crater run which came back clean: https://github.com/rust-lang/rust/pull/139042#issuecomment-2767436367

As a side-note, it may be tempting to suggest that this is actually a good thing or that we should preserve this behavior. If we wanted to make this work (i.e. trivially optimize out reads from matches that are redundant like `0 | _`), then we should be enabling this behavior *after* fixing this. However, I think it's kinda unprincipled, and for example other variations of the code don't even work today, e.g.:

```rust
fn foo() {
    let x;
    let (0.. | _) = x;
}
```
2025-04-19 19:30:46 +00:00
Chris Denton
f0a0efdcdc
Rollup merge of #139995 - spencer3035:clean-ui-tests-4-of-n, r=jieyouxu
Clean UI tests 4 of n

Cleaned up some tests that have `issue` in the title. I kept the commits to be one per "`issue`" cleanup/rename to make it easier to check. I can rebase to one commit once the changes are approved.

Related Issues:
#73494
#133895

r? jieyouxu
2025-04-19 15:09:36 +00:00
Chris Denton
aad59a30de
Rollup merge of #139091 - mejrs:format, r=compiler-errors
Rewrite on_unimplemented format string parser.

This PR rewrites the format string parser for `rustc_on_unimplemented` and `diagnostic::on_unimplemented`. I plan on moving this code (and more) into the new attribute parsing system soon and wanted to PR it separately.

This PR introduces some minor differences though:
- `rustc_on_unimplemented` on trait *implementations* is no longer checked/used - this is actually never used (outside of some tests) so I plan on removing it in the future.
- for `rustc_on_unimplemented`, it introduces the `{This}` argument in favor of `{ThisTraitname}` (to be removed later). It'll be easier to parse.
- for `rustc_on_unimplemented`, `Self` can now consistently be used as a filter, rather than just `_Self`. It used to not match correctly on for example `Self = "[{integer}]"`
- Some error messages now have better spans.

Fixes https://github.com/rust-lang/rust/issues/130627
2025-04-19 15:09:33 +00:00