Rollup of 16 pull requests by Zalathar · Pull Request #162887 · rust-lang/rust

Zalathar · 2026-09-17T06:03:25Z

Successful merges:

coretests: Add more pattern tests. #161596 (coretests: Add more pattern tests.)
libtest: do not early exit from test runners #162796 (libtest: do not early exit from test runners)
Add loan reachability traces to polonius MIR dumps #162844 (Add loan reachability traces to polonius MIR dumps)
Move operations out of rustc_middle::query::job #162876 (Move operations out of rustc_middle::query::job)
Stabilize windows_process_extensions_main_thread_handle #160108 (Stabilize windows_process_extensions_main_thread_handle)
traits: Fix rigid alias liveness matching #160212 (traits: Fix rigid alias liveness matching)
Stabilize feature(trim_prefix_suffix) ({str, [T], Path}::trim_prefix and {str, [T]}::trim_suffix) #160544 (Stabilize feature(trim_prefix_suffix) ({str, [T], Path}::trim_prefix and {str, [T]}::trim_suffix))
Normalize non-rigid aliases in ty_known_to_outlive #161246 (Normalize non-rigid aliases in ty_known_to_outlive)
Use the entire type of a dropped local to compute variance (edge direction) for Polonius alpha #161305 (Use the entire type of a dropped local to compute variance (edge direction) for Polonius alpha)
tests: accept LLVM 24 optimization in this test #161838 (tests: accept LLVM 24 optimization in this test)
Add must_use lint to ExitCode #162805 (Add must_use lint to ExitCode)
core: Add examples for debug_closure_helpers #162825 (core: Add examples for debug_closure_helpers)
enable asm tests for xtensa targets #162841 (enable asm tests for xtensa targets)
reintroduce check RibKind::ConstParamTy did in direct consts #162842 (reintroduce check RibKind::ConstParamTy did in direct consts)
mgca: fix issue with mismatched array valtree/valtree tys #162845 (mgca: fix issue with mismatched array valtree/valtree tys)
Stabilize CommandExt::show_window #162856 (Stabilize CommandExt::show_window)

Giving access to `std::os::windows::process::ChildExt::main_thread_handle()`.

It does not look like these items are actually used by rustc.

This is to make it easy to update the static template, like its skeleton or style, and add features there, instead of doing it all with rust code. The dynamic sections are marked as dummy tokens and are replaced when dumping the MIR.

display a list of all the nodes each loan can reach (and whether the node's region is live at the node's point)

Loan traces can be big and numerous, so we hide them by default. We instead use a button to show a loan's trace.

margins and spacing, section separators, reachability layout, etc.

This API is in FCP, but there are no examples and much of it is untested. Add examples here.

Signed-off-by: Amirhossein Akhlaghpour <m9.akhlaghpoor@gmail.com>

Item bounds already instantiate higher-ranked GAT arguments with identity parameters. Compare the bound self type with the identity alias directly, and treat any remaining bound region as static.

Co-authored-by: Amanda Stjerna <amanda@stjerna.space> Co-authored-by: Jack Huey <31162821+jackh726@users.noreply.github.com>

Right now things are undertested and underspecified. Some of the library code would get in a loop if searcher starts returning empty rejects. And there's no tests for backwards multi byte char matchers. Pull request I'm reviving had a problem implementing that, so making sure it's tested before the actual code lands. Right now it is possible to break both tests (and user code) without breaking anything else in the test suite I think.

LLVM prior to 24 didn't do some optimizations around call slots on pointers without `dereferenceable` set. A recent change enhanced the optimizer so it can handle that case (at least in this test) so we relax the checks here slightly. We still (from what I can tell) demonstrate that `sse41_blend_nofeature` is not inlined, which seems to be the import part of this region of the test.

Generally `rustc_middle::query` has types while `rustc_query_impl` has operations. So this commit moves some operations from the former to the latter. Some of them are just moved, while others are inlined and removed.

@Mark-Simulacrum

…oli-obk libtest: do not early exit from test runners Suggested by @Mark-Simulacrum in rust-lang#161868. I finally figured out why my earlier attempts did not work.

@jackh726

Add loan reachability traces to polonius MIR dumps This expands the Polonius MIR dumps to add traces of all the nodes a loan traverses (and if the region it reaches is live at that point). This helps with debugging and analyzing borrow-checking, of soundness issues in particular, as they manifest as a *lack* of reachability in the localized outlives graph. Since there can be many loans and the traces can be big, they're hidden by default until a button is clicked. I've uploaded an [example here](https://gistpreview.github.io/?b8b9218f6565f3b13f91a63859ad776e) so it's easier to test. <sub>This feels like a good enough start, but there's definitely many expansions I'd like to make to this feature in future PRs. Some of which I've already done in [older prototypes](https://gistpreview.github.io/?4098d51d4f4e12e2a61a673b60d94690).</sub> More easily reviewed per commit. r? @jackh726 (also cc @amandasystems as we were all discussing things like this to help with the unsoundness analyses)

@Zalathar

…ddle-query-job, r=Zalathar Move operations out of `rustc_middle::query::job` Generally `rustc_middle::query` has types while `rustc_query_impl` has operations. So this commit moves some operations from the former to the latter. Some of them are just moved, while others are inlined and removed. r? @Zalathar

…ead-windows, r=clarfonthey Stabilize `windows_process_extensions_main_thread_handle` I propose we stabilize the library feature `windows_process_extensions_main_thread_handle` (tracking issue rust-lang#96723). ## Stabilization Report ### Implementation History This feature was added in rust-lang#96725, and not changed since. ### API Summary ```rust // std::os::windows::process pub trait ChildExt: Sealed { fn main_thread_handle(&self) -> BorrowedHandle<'_>; } ``` This method gives access to the handle to the main thread of a spawned child process on Windows. It is not possible to get after spawning using documented APIs, and it's useful for example for resuming a process that started as suspended (while it's possible to enumerate all threads and resume them all, that's slower and more complicated). ### Experience Report My personal reason for this is wanting to use it for this case exactly (resuming a suspended process) in rust-analyzer, see rust-lang/rust-analyzer#22763 (comment). Other people seem to want this for the same reason as well (for example in the tracking issue). [Searching GitHub for `.main_thread_handle()` gives 269 results](https://github.com/search?q=%22.main_thread_handle%28%29%22+language%3Arust&type=code). Some are for resuming processes, but there are also others - for example, [injecting a DLL](https://github.com/garyttierney/me3/blob/a1e26958d8e141864d3adfcbbef4f2f669b5c8ef/crates/launcher/src/game.rs#L98). I [even found a project](https://github.com/GitFlameAI/GitFlame-CodeRAG/blob/3684d2dc846831f9805bec4486e60296c232f974/datasets/repositories/repo_020_hyperfine/code/src/timer/windows_timer.rs#L71) that gates using this method behind a feature, and if it's not set, uses an undocumented Windows API instead. ### Unresolved Questions There are two unresolved questions: - The naming - should it be the "main thread" or the "primary thread". Microsoft's documentation refers to it as the "primary thread", but our own docs mention "main thread" (https://doc.rust-lang.org/std/thread/index.html), as stated in rust-lang#96723 (comment). I left it as "main thread". - Should it return `Option<BorrowedHandle<'_>>`? This will enable conversion from a handle to `std::process::Child` (such conversion is not supported currently). Such conversion is not supported for any OS currently though, and making this function returning `Option` will complicate code using it, so I chose to not do that. r? libs-api

…eness, r=adwinwhite traits: Fix rigid alias liveness matching Fixes rust-lang#160206 The ICE happens while borrowck computes liveness for an opaque return type with an associated type bound. In the repro, that bound looks like `<impl Foo<'x> as Foo<'x>>::Out: 'static`. The query passes unnormalized item bounds to `extract_verify_if_eq`, which expects rigid aliases with the next solver, and hits its debug assertion. Item-bound collection already maps higher-ranked GAT arguments to the GAT's identity parameters. That means this query can compare the bound's self type directly with the identity alias. A bound on a nested projection, like the associated type in the repro, doesn't match the opaque itself and gets skipped. It doesn't tell us that the opaque is `'static`. For bounds that do match, we keep the outlives region unless it's still bound. For example, `for<'b> Self::Assoc<'b>: 'b` becomes a non higher ranker item bound `Self::Assoc<'param>: 'param`, so that param region still matters for liveness. With `for<'b> Self::Assoc: 'b`, the same associated type has to outlive every choice of `'b`, including `'static`. We handle that case directly. I think this is a better fit for the query because it uses the work item-bound collection already did. It removes the matcher call from this path and keeps the shared matcher's rigidity checks intact. The separate call for function bounds stays, since it still needs to match against the alias's concrete arguments. There's no extra normalization in liveness. The original repro covers the case that triggered the assertion: an item bound on a nested projection must be skipped when computing liveness for the opaque itself.

…ix, r=clarfonthey Stabilize `feature(trim_prefix_suffix)` (`{str, [T], Path}::trim_prefix` and `{str, [T]}::trim_suffix`) Closes rust-lang#142312 (tracking issue) FCP completed [here](rust-lang#142312 (comment)). There was discussion during FCP about a possibly adding `strip_circumfix`, but that wasn't mentioned as blocking. r? libs-api

…s, r=adwinwhite Normalize non-rigid aliases in ty_known_to_outlive Fixes rust-lang#161067 `ty_known_to_outlive` directly registers a TypeOutlives region obligation without normalization. With the next solver, we do not expect non-rigid aliases in lexical region solving. Normalize non-rigid aliases before registering the obligation while avoiding trait solving for inputs that do not contain them.

…jackh726 Use the entire type of a dropped local to compute variance (edge direction) for Polonius alpha Fixes: rust-lang#160670 The soundness issue is caused by (as suggested by the text extruder) the incorrect variance for a region, which is supposed to be bidirectional (invariant) but is registered as contravariant. Starting with this example (from the issue): ```rust use std::fmt::Debug; struct D<T: HasArg>(T::Arg); trait HasArg { type Arg: Debug; } impl<'a, T: Debug> HasArg for fn(&'a T) { type Arg = &'a T; } impl<T: HasArg> Drop for D<T> { fn drop(&mut self) { println!("{:?}", self.0); } } fn mk<'a, T: Debug>(r: &'a T) -> D<fn(&'a T)> { D(r) } fn main() { let b = Box::new(vec![vec![1]]); let d; d = mk(&*b); drop(b); // ERROR: move out of borrowed... } ``` This generates a path through MIR on the way to a drop that looks like this: ```MIR _1 = move _2 /// ... drop(_1) ``` In this instance, the types of `_1` and `_2` are `D<fn(&'?1 Vec<...>)` and `D<fn(&'?2 Vec<...>)` respectively. During liveness computation (in `liveness::trace`) region liveness is computed from drop liveness and use liveness. Additionally, for each live region (drop-live or use-live), region variance is computed for Polonius' loan propagation. Variance determines the direction of propagation across program flow. For drop-live locals (variables), the types reported in ` DropckOutlivesResult::kinds` are used to register drop live regions and compute their variances. However, instead of using the full type `D<...>` for the left-hand side of this assignment statement, `kinds` starts with a `Binder {...}` and the function type inside of it. From that it finds region `'?1` and records it as contravariant (backwards propagated). This PR addresses the issue by using the entire type of the drop-live local to compute the variance of any regions referenced inside it, at the cost of potentially doing unnecessary extra work, ~~either when iteration continues over `DropckOutlivesResult::kinds` (which should be redundant with it in most cases), or~~ if the local contains a region whose variance is actually not needed for computation or in regard to drop liveness (assuming that ever happens). It also adds some debug statements that helped me debug the issue, and a ui test for the soundness issue.

@rustbot

…rget-feature, r=nikic tests: accept LLVM 24 optimization in this test LLVM prior to 24 didn't do some optimizations around call slots on pointers without `dereferenceable` set. A [recent change](llvm/llvm-project@8a4a0f26704b) enhanced the optimizer so it can handle that case (at least in this test) so we relax the checks here slightly. We still (from what I can tell) demonstrate that `sse41_blend_nofeature` is not inlined, which seems to be the import part of this region of the test. @rustbot label: +llvm-main

@BoxyUwU

…BoxyUwU mgca: fix issue with mismatched array valtree/valtree tys fixes rust-lang#160553 reimplements rust-lang#158587 in a different way (please see that PR for context, much of this PR's diff is undoing that PR's diff) r? @BoxyUwU

…ow-window, r=jhpratt Stabilize CommandExt::show_window Stabilize `std::os::windows::process::CommandExt::show_window`. The final comment period of rust-lang#127544 was completed. rust-lang#127544 (comment) I have been using this function for 2 years. I want to use this function on stable Rust. So, I open a pull request. `windows_process_extensions_show_window` feature appears only in the location I modified. ``` > rg 'windows_process_extensions_show_window' src/tools/rust-analyzer/crates/ide-db/src/generated/lints.rs 17165: label: "windows_process_extensions_show_window", 17166: description: r##"# `windows_process_extensions_show_window` library/std/src/os/windows/process.rs 191: #[stable(feature = "windows_process_extensions_show_window", since = "CURRENT_RUSTC_VERSION")] ``` LLM disclosure: I asked an ChatGPT for the steps and manually created a commit. I handled the searching for the code to modify (using `rg`) and the actual editing (using `nano`) myself.

Zalathar · 2026-09-17T06:04:04Z

Rollup of everything (excluding perf-sensitive PRs).

@bors r+ rollup=never p=5

rust-bors · 2026-09-17T06:04:06Z

📌 Commit 3f902cc has been approved by Zalathar

It is now in the queue for this repository.

Zalathar · 2026-09-17T06:04:31Z

Trying commonly-failed jobs:

@bors try jobs=dist-various-1,test-various,test-x86_64-gnu-aux,test-x86_64-gnu-llvm-21-3,test-x86_64-msvc-1,test-aarch64-apple-1,test-aarch64-apple-2,test-x86_64-mingw-1,test-i686-msvc,test-armhf-gnu

Rollup of 16 pull requests try-job: dist-various-1 try-job: test-various try-job: test-x86_64-gnu-aux try-job: test-x86_64-gnu-llvm-21-3 try-job: test-x86_64-msvc-1 try-job: test-aarch64-apple-1 try-job: test-aarch64-apple-2 try-job: test-x86_64-mingw-1 try-job: test-i686-msvc try-job: test-armhf-gnu

rust-bors · 2026-09-17T09:06:22Z

☀️ Try build successful (CI)
Build commit: 82c4c7f (82c4c7f8cef68febc4d5707b29c875cee82efa84)
Base parent: 923c95c (923c95cdf5ba65cea505aa2ea829f578e1506ed8)

rust-bors · 2026-09-17T09:23:28Z

⌛ Testing commit 3f902cc with merge 51fad75...

Workflow: https://github.com/rust-lang/rust/actions/runs/35204854384

Rollup of 16 pull requests Successful merges: - #161596 (coretests: Add more pattern tests.) - #162796 (libtest: do not early exit from test runners) - #162844 (Add loan reachability traces to polonius MIR dumps) - #162876 (Move operations out of `rustc_middle::query::job`) - #160108 (Stabilize `windows_process_extensions_main_thread_handle`) - #160212 (traits: Fix rigid alias liveness matching) - #160544 (Stabilize `feature(trim_prefix_suffix)` (`{str, [T], Path}::trim_prefix` and `{str, [T]}::trim_suffix`)) - #161246 (Normalize non-rigid aliases in ty_known_to_outlive) - #161305 (Use the entire type of a dropped local to compute variance (edge direction) for Polonius alpha) - #161838 (tests: accept LLVM 24 optimization in this test) - #162805 (Add `must_use` lint to `ExitCode`) - #162825 (core: Add examples for `debug_closure_helpers`) - #162841 (enable asm tests for xtensa targets) - #162842 (reintroduce check RibKind::ConstParamTy did in direct consts) - #162845 (mgca: fix issue with mismatched array valtree/valtree tys) - #162856 (Stabilize CommandExt::show_window)

rust-bors · 2026-09-17T11:39:47Z

PR #161246, which is a member of this rollup, changed its commit SHA.

This rollup was thus unapproved due to being closed.

Auto build was cancelled due to push. Cancelled workflows:

https://github.com/rust-lang/rust/actions/runs/35204854384

ChayimFriedman2 and others added 30 commits August 10, 2026 01:08

Stabilize windows_process_extensions_main_thread_handle

8a7ec34

Giving access to `std::os::windows::process::ChildExt::main_thread_handle()`.

libtest: do not early exit from test runners

6401a6e

clean up libtest re-exports a bit

5fd598e

It does not look like these items are actually used by rustc.

add loan reachability to the polonius mir dump

6f49dfe

display a list of all the nodes each loan can reach (and whether the node's region is live at the node's point)

make loan traces opt in

5e715e0

Loan traces can be big and numerous, so we hide them by default. We instead use a button to show a loan's trace.

improve visuals

2cd2f3d

margins and spacing, section separators, reachability layout, etc.

core: Add examples for debug_closure_helpers

6b96623

This API is in FCP, but there are no examples and much of it is untested. Add examples here.

Stabilize trim_prefix_suffix

9559b38

enable asm tests for xtensa targets

076a758

fix: normalize non-rigid aliases in ty_known_to_outlive

7f7e359

Signed-off-by: Amirhossein Akhlaghpour <m9.akhlaghpoor@gmail.com>

mgca: fix issue with mismatched array valtree/valtree tys

babc228

reintroduce check for ConstParamTy in direct consts

9dce1fc

Read alias liveness directly from item bounds

fb554f2

Item bounds already instantiate higher-ranked GAT arguments with identity parameters. Compare the bound self type with the identity alias directly, and treat any remaining bound region as static.

Stabilize CommandExt::show_window

94cc692

Use the entire type of the live variable to compute region variance

8265b6f

Co-authored-by: Amanda Stjerna <amanda@stjerna.space> Co-authored-by: Jack Huey <31162821+jackh726@users.noreply.github.com>

Add must_use lint to ExitCode

99261fb

Move operations out of rustc_middle::query::job

79d24a0

Generally `rustc_middle::query` has types while `rustc_query_impl` has operations. So this commit moves some operations from the former to the latter. Some of them are just moved, while others are inlined and removed.

Rollup merge of rust-lang#162796 - RalfJung:libtest-no-early-exit, r=…

b9747fb

…oli-obk libtest: do not early exit from test runners Suggested by @Mark-Simulacrum in rust-lang#161868. I finally figured out why my earlier attempts did not work.

Zalathar added 2 commits September 17, 2026 16:03

rust-bors Bot added the rollup A PR which is a rollup label Sep 17, 2026

rust-bors Bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Sep 17, 2026

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Rollup of 11 pull requests #162878

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rust-bors Bot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Sep 17, 2026

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Normalize non-rigid aliases in ty_known_to_outlive #161246

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Zalathar deleted the rollup-JxWLBGL branch September 17, 2026 12:16

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Rollup of 16 pull requests - #162887

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