Rollup of 10 pull requests by JonathanBrouwer · Pull Request #154222 · rust-lang/rust

JonathanBrouwer · 2026-03-22T19:27:03Z

Successful merges:

std: include dlmalloc for all non-wasi Wasm targets #153686 (std: include dlmalloc for all non-wasi Wasm targets)
Fix environ on FreeBSD with cdylib targets that use -Wl,--no-undefined . #153718 (Fix environ on FreeBSD with cdylib targets that use -Wl,--no-undefined .)
Lifted intersperse and intersperse_with Fused transformation and updated documentation + tests #153880 (Lifted intersperse and intersperse_with Fused transformation and updated documentation + tests)
remove usages of to-be-deprecated numeric constants #153931 (remove usages of to-be-deprecated numeric constants)
Unknown -> Unsupported compression algorithm #150630 (Unknown -> Unsupported compression algorithm)
std: move sys::pal::os to sys::paths #153623 (std: move sys::pal::os to sys::paths)
docs(fs): Clarify That File::lock Coordinates Across Processes #153647 (docs(fs): Clarify That File::lock Coordinates Across Processes)
Skip stack_start_aligned for immediate-abort #153936 (Skip stack_start_aligned for immediate-abort)
implement BinaryHeap::as_mut_slice #154011 (implement BinaryHeap::as_mut_slice)
ui/lto: move and rename two tests from issues/ #154167 (ui/lto: move and rename two tests from issues/)

Instead of relying on the linker to find the 'environ' symbol, use dlsym. Fixes rust-lang#153451 Sponsored by: ConnectWise

Currently, building std for a custom Wasm target with an OS other than `unknown` will fail, because `sys/alloc/mod.rs` will attempt to use `sys/alloc/wasm.rs`, the dlmalloc-based allocator used on `wasm32-unknown-unknown`. However, currently dlmalloc is only pulled in when `target_os = "unknown"`. Instead, we should make `Cargo.toml` and `alloc/mod.rs` match: either - disable `wasm.rs` in `alloc/mod.rs` where `not(target_os = "unknown")`, or - pull in `dlmalloc` for all Wasm targets with `target_family = "wasm32"` that aren't covered by the [upper branches of `alloc/mod.rs`](https://github.com/rust-lang/rust/blob/main/library/std/src/sys/alloc/mod.rs#L72-L100). This PR takes the latter approach, because it allows more code to compile without a custom allocator.

…d documentation + tests

This improves startup performance by 16%, shown by an optimized hello-world program. glibc's `pthread_getattr_np` performs expensive syscalls when reading `/proc/self/maps`. That is all wasted with `panic = immediate-abort` active because `init()` immediately discards the return value from `install_main_guard()`. A similar improvement can be seen in environments that don't have `/proc`. This change is safe because the immediately succeeding comment says that we rely on Linux's "own stack-guard mechanism".

…s/ui/lto/

…riginate from

Both zstd and zlib are *known* compression algorithms, they just may not be supported by the backend. We shouldn't mislead users into e.g. thinking they made a typo.

`std`: include `dlmalloc` for all non-wasi Wasm targets Currently, building std for a custom Wasm target with an OS other than `unknown` will fail, because `sys/alloc/mod.rs` will attempt to use `sys/alloc/wasm.rs`, the dlmalloc-based allocator used on `wasm32-unknown-unknown`. However, currently dlmalloc is only pulled in when `target_os = "unknown"`. Instead, we should make `Cargo.toml` and `alloc/mod.rs` match: either - disable `wasm.rs` in `alloc/mod.rs` where `not(target_os = "unknown")`, or - pull in `dlmalloc` for all Wasm targets with `target_family = "wasm32"` that aren't covered by the [upper branches of `alloc/mod.rs`](https://github.com/rust-lang/rust/blob/main/library/std/src/sys/alloc/mod.rs#L72-L100). This PR takes the latter approach, because it allows more code to compile without a custom allocator.

…mulacrum Fix environ on FreeBSD with cdylib targets that use -Wl,--no-undefined . Instead of relying on the linker to find the 'environ' symbol, use dlsym. This fixes using `environ` from cdylibs that link with `-Wl,--no-undefined` . Fixes rust-lang#153451 Sponsored by: ConnectWise

@jhpratt

…Mark-Simulacrum Lifted intersperse and intersperse_with Fused transformation and updated documentation + tests This PR once again builds on top of rust-lang#152855. From the discussion in rust-lang#152855, libs team came to the conclusion that `intersperse`/`intersperse_with` shouldn't transform the given iterator to a fused iterator always and a separator should be emitted between `Some(_)` items for non fused iterators (particularly just right before the subsequent `Some(_)`). On top of the change Zakarumych added in the PR, I lifted the `FusedIterator` trait and transformation of the inner `iter` for `Intersperse`/`IntersperseWith`, so that we can display this behavior. I've adjusted the documentation and tests accordingly to reflect this change as well. r? @jhpratt

remove usages of to-be-deprecated numeric constants Split out from rust-lang#146882.

…on-warn, r=JonathanBrouwer Unknown -> Unsupported compression algorithm Both zstd and zlib are *known* compression algorithms, they just may not be supported by the backend. We shouldn't mislead users into e.g. thinking they made a typo. cc rust-lang#120953

@jethrogb

std: move `sys::pal::os` to `sys::paths` Part of rust-lang#117276. After rust-lang#150723, rust-lang#153130, rust-lang#153341 and rust-lang#153413, `sys::pal::os` only contains default-path related functions (like `getcwd` and the `PATH`-splitting logic). In line with rust-lang#117276, this PR thus moves all these implementations into a new module in `sys`: `sys::paths`. ~There is one functional change here: The `chdir` implementation on SGX used to use `sgx_ineffective` which silently fails, but now returns an error unconditionally – I think that's much more reasonable given that SGX doesn't support filesystem stuff at all.~ I've corrected the misleading panic messages in `temp_dir` for UEFI and WASI, aside from that, this PR only consists of code moves. CC @jethrogb @raoulstrackx @aditijannu for the SGX change (resolved)

@Mark-Simulacrum

…process, r=Mark-Simulacrum docs(fs): Clarify That File::lock Coordinates Across Processes ### Summary: The documentation for `lock`, `lock_shared`, `try_lock`, and `try_lock_shared` did not make it clear that these are OS level file locks that coordinate access across processes, not just between handles within the current process. Add "in this or any other process" to each method's existing description to clarify this. Fixes rust-lang#153618 r? @Mark-Simulacrum

…dPthreadGetattrNp, r=Mark-Simulacrum Skip stack_start_aligned for immediate-abort This improves startup performance by 16%, shown by an optimized hello-world program. glibc's `pthread_getattr_np` performs expensive syscalls when reading `/proc/self/maps`. That is all wasted with `panic = immediate-abort` active because `init()` immediately discards the return value from `install_main_guard()`. A similar improvement can be seen in environments that don't have `/proc`. This change is safe because the immediately succeeding comment says that we rely on Linux's "own stack-guard mechanism". Tracking issue: rust-lang#147286 # Benchmark Set it up with `cargo new hello-world2`, and replace these files: ```toml # Cargo.toml cargo-features = ["panic-immediate-abort"] [package] name = "hello-world" version = "0.1.0" edition = "2024" [profile.release] lto = true panic = "immediate-abort" codegen-units = 1 opt-level = "z" strip = true # .cargo/config.toml [unstable] build-std = ["std"] ``` ## Before ```console home@daniel-desktop3:~/CLionProjects/hello-world2$ hyperfine -N target/release/hello-world2 Benchmark 1: target/release/hello-world2 Time (mean ± σ): 524.8 µs ± 65.1 µs [User: 276.1 µs, System: 187.0 µs] Range (min … max): 446.4 µs … 975.5 µs 3996 runs home@daniel-desktop3:~/CLionProjects/hello-world2$ hyperfine -N target/release/hello-world2 Benchmark 1: target/release/hello-world2 Time (mean ± σ): 519.4 µs ± 65.8 µs [User: 282.1 µs, System: 177.7 µs] Range (min … max): 443.2 µs … 830.5 µs 3612 runs home@daniel-desktop3:~/CLionProjects/hello-world2$ hyperfine -N target/release/hello-world2 Benchmark 1: target/release/hello-world2 Time (mean ± σ): 520.0 µs ± 64.3 µs [User: 277.1 µs, System: 182.1 µs] Range (min … max): 447.1 µs … 1001.3 µs 3804 runs ``` For a visualization of the problem, run `cargo +stage1 build --release && perf record --call-graph dwarf -F max ./target/release/hello-world2 && perf script | inferno-collapse-perf | inferno-flamegraph > flamegraph.svg`: <img width="3832" height="1216" alt="flamegraph with 17.41% __pthread_getattr_np" src="https://github.com/user-attachments/assets/acc2286e-1582-4772-9e3b-68b5c35e3e70" /> ## After ```console home@daniel-desktop3:~/CLionProjects/hello-world2$ hyperfine -N target/release/hello-world2Benchmark 1: target/release/hello-world2 Time (mean ± σ): 444.7 µs ± 57.3 µs [User: 257.4 µs, System: 130.2 µs] Range (min … max): 379.4 µs … 1289.3 µs 3893 runs Warning: Statistical outliers were detected. Consider re-running this benchmark on a quiet system without any interferences from other programs. It might help to use the '--warmup' or '--prepare' options. home@daniel-desktop3:~/CLionProjects/hello-world2$ hyperfine -N target/release/hello-world2 Benchmark 1: target/release/hello-world2 Time (mean ± σ): 452.3 µs ± 60.7 µs [User: 261.5 µs, System: 133.5 µs] Range (min … max): 374.9 µs … 1512.4 µs 4177 runs Warning: Statistical outliers were detected. Consider re-running this benchmark on a quiet system without any interferences from other programs. It might help to use the '--warmup' or '--prepare' options. home@daniel-desktop3:~/CLionProjects/hello-world2$ hyperfine -N target/release/hello-world2 Benchmark 1: target/release/hello-world2 Time (mean ± σ): 441.2 µs ± 56.1 µs [User: 256.2 µs, System: 128.8 µs] Range (min … max): 375.0 µs … 760.4 µs 4032 runs ```

…=Mark-Simulacrum implement `BinaryHeap::as_mut_slice` Tracking issue: rust-lang#154009

…ts, r=Kivooeo ui/lto: move and rename two tests from issues/ Move: - `tests/ui/issues/issue-44056.rs` -> `tests/ui/lto/lto-avx-target-feature.rs` - The first test enables both AVX target features and LTO but does not exercise AVX-specific behavior. The test primarily checks that LTO builds successfully with these flags; place it under `ui/lto` for consistency. - `tests/ui/issues/issue-51947.rs` -> `tests/ui/lto/lto-weak-merge-functions.rs` - The second test exercises weak linkage interacting with LTO (merge-functions), so it should belong in `ui/lto`. I have also added a commented line at the top of each test file indicating the issue it originated from.

JonathanBrouwer · 2026-03-22T19:27:15Z

@bors r+ rollup=never p=3

rust-bors · 2026-03-22T19:27:18Z

📌 Commit d790229 has been approved by JonathanBrouwer

It is now in the queue for this repository.

JonathanBrouwer · 2026-03-22T19:27:18Z

Trying commonly failed jobs
@bors try jobs=test-various,x86_64-gnu-aux,x86_64-gnu-llvm-21-3,x86_64-msvc-1,aarch64-apple,x86_64-mingw-1

Rollup of 10 pull requests try-job: test-various try-job: x86_64-gnu-aux try-job: x86_64-gnu-llvm-21-3 try-job: x86_64-msvc-1 try-job: aarch64-apple try-job: x86_64-mingw-1

JonathanBrouwer · 2026-03-22T19:36:02Z

Just wanted to get some try jobs started already, feel free to recreate this PR when more stuff enters the queue

rust-bors · 2026-03-22T21:24:58Z

This pull request was unapproved due to being closed.

rust-bors · 2026-03-22T22:39:43Z

☀️ Try build successful (CI)
Build commit: 27ac14a (27ac14a31b72832ef367db90b7799833a523500c, parent: 562dee4820c458d823175268e41601d4c060588a)

asomers and others added 25 commits March 9, 2026 09:19

Fix environ on FreeBSD with cdylib targets that use -Wl,--no-undefined .

44d6cd2

Instead of relying on the linker to find the 'environ' symbol, use dlsym. Fixes rust-lang#153451 Sponsored by: ConnectWise

std: move sys::pal::os to sys::paths (rename/delete only)

d2e3ab6

std: move leftover Windows error test

f4a95d3

std: move sys::pal::os to sys::paths

be5f070

docs(fs): Clarify that File::lock coordinates across processes

0e0babc

std: don't depend on dlmalloc when cfg(unix)

e2923eb

Do not emit separator as before elements

425df0d

Lifted intersperse and intersperse_with Fused restrictions and update…

800d9ea

…d documentation + tests

remove usages of to-be-deprecated numeric constants

a893257

implement BinaryHeap::as_mut_slice

cab72ae

Move and rename LTO-specific test files from tests/ui/issues/ to test…

9b7dff9

…s/ui/lto/

Add comment at the top in two test files referencing the issue they o…

dd2b208

…riginate from

Unknown -> Unsupported compression algorithm

6458ca5

Both zstd and zlib are *known* compression algorithms, they just may not be supported by the backend. We shouldn't mislead users into e.g. thinking they made a typo.

Rollup merge of rust-lang#153931 - cyrgani:old-consts, r=Mark-Simulacrum

fbaafdc

remove usages of to-be-deprecated numeric constants Split out from rust-lang#146882.

Rollup merge of rust-lang#154011 - usamoi:binary_heap_as_mut_slice, r…

3db6a12

…=Mark-Simulacrum implement `BinaryHeap::as_mut_slice` Tracking issue: rust-lang#154009

rust-bors bot added the rollup A PR which is a rollup label Mar 22, 2026

rustbot added A-LLVM Area: Code generation parts specific to LLVM. Both correctness bugs and optimization-related issues. A-run-make Area: port run-make Makefiles to rmake.rs O-hermit Operating System: Hermit O-SGX Target: SGX labels Mar 22, 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 Mar 22, 2026

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JonathanBrouwer mentioned this pull request Mar 22, 2026

Rollup of 22 pull requests #154227

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JonathanBrouwer closed this Mar 22, 2026

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 Mar 22, 2026

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Rollup of 10 pull requests#154222

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