Remove needless unsafety from BTreeMap::drain_filter
Remove one piece of unsafe code in the iteration over the iterator returned by BTreeMap::drain_filter.
- Changes an explicitly unspecified part of the API: when the user-supplied predicate (or some of BTreeMap's code) panicked, and the caller tries to use the iterator again, we no longer offer the same key/value pair to the predicate again but pretend the iterator has finished. Note that Miri does not find UB in the test case added here with the unsafe code (or without).
- Makes the code a little easier on the eyes.
- Makes the code a little harder on the CPU:
```
benchcmp c0 c2 --threshold 3
name c0 ns/iter c2 ns/iter diff ns/iter diff % speedup
btree::set::clone_100_and_drain_all 2,794 2,900 106 3.79% x 0.96
btree::set::clone_100_and_drain_half 2,604 2,964 360 13.82% x 0.88
btree::set::clone_10k_and_drain_half 287,770 322,755 34,985 12.16% x 0.89
```
r? @Amanieu
More BTreeMap test cases, some exposing undefined behaviour
Gathered from other ongoing PRs and all either blessed or ignored by Miri
r? @Mark-Simulacrum
Internally unify rustc_deprecated and deprecated
This PR intentionally tries to be "featureless" in that the behavior is not altered for either attribute, though it more clearly exposes cases where that is the case in the code.
Revert libbacktrace -> gimli
This reverts 4cbd265c119cb1a5eb92e98d2bb93466f05efa46 028f8d7b85898683b99e05564cd2976c7e0d5b43 13db3cc1e8d2fd4b8e7c74d91002274d7b62801b d7a36d8964c927863faef5d3b42da08f37e5896c (and technically 79673d300915f846726c27b9e1974dc451013ee9 but it's made empty by previous reverts).
The current plan is to land this PR as a temporary change, so that we can get a better handle on the regressions introduced by it. Trying to fix/examine them in master is difficult, and we want to be better able to evaluate them without impact to other PRs being landed in the mean time.
That said, it is currently *my* belief that gimli, in one form or another, will need to land sometime soon. I think it's quite likely that it may slip a week or two, but I would personally push for re-landing it then "regardless" of the regressions. We should try to focus efforts on understanding and removing as much of the performance impact as possible, as everyone pretty much agrees that it should be quite minimal (and entirely in the linker, basically).
r? @nnethercote
Rollup of 8 pull requests
Successful merges:
- #74141 (libstd/libcore: fix various typos)
- #74490 (add a Backtrace::disabled function)
- #74548 (one more Path::with_extension example, to demonstrate behavior)
- #74587 (Prefer constant over function)
- #74606 (Remove Linux workarounds for missing CLOEXEC support)
- #74637 (Make str point to primitive page)
- #74654 (require type defaults to be after const generic parameters)
- #74659 (Improve codegen for unchecked float casts on wasm)
Failed merges:
r? @ghost
Improve codegen for unchecked float casts on wasm
This commit improves codegen for unchecked casts on WebAssembly targets
to use the singluar `iNN.trunc_fMM_{u,s}` instructions. Previously rustc
would codegen a bare `fptosi` and `fptoui` for float casts but for
WebAssembly targets the codegen for these instructions is quite large.
This large codegen is due to the fact that LLVM can speculate these
instructions so the trapping behavior of WebAssembly needs to be
protected against in case they're speculated.
The change here is to update the codegen for the unchecked cast
intrinsics to have a wasm-specific case where they call the appropriate
LLVM intrinsic to generate the right wasm instruction. The intrinsic is
explicitly opting-in to undefined behavior so a trap here for
out-of-bounds inputs on wasm should be acceptable.
cc #73591
require type defaults to be after const generic parameters
From current discussions it seems like the goal here is for type and const parameters to be unordered and allow things like `struct Foo<const N: usize, T = u32>(T)` and `struct Foo<T, const N: usize = 7>` this way.
Note: This means that using `min_const_generics` it will not be possible for an adt to have both type defaults and const parameters.
closes#70471
r? @varkor @eddyb
Remove Linux workarounds for missing CLOEXEC support
Now that #74163 updated the minimum Linux kernel to 2.6.32, we can
assume the availability of APIs that open file descriptors that are
already set to close on exec, including the flags `O_CLOEXEC`,
`SOCK_CLOEXEC`, and `F_DUPFD_CLOEXEC`.
Closes#74519.
Rollup of 9 pull requests
Successful merges:
- #73783 (Detect when `'static` obligation might come from an `impl`)
- #73868 (Advertise correct stable version for const control flow)
- #74460 (rustdoc: Always warn when linking from public to private items)
- #74538 (Guard against non-monomorphized type_id intrinsic call)
- #74541 (Add the aarch64-apple-darwin target )
- #74600 (Enable perf try builder)
- #74618 (Do not ICE on assoc type with bad placeholder)
- #74631 (rustc_target: Add a target spec option for disabling `--eh-frame-hdr`)
- #74643 (build: Remove unnecessary `cargo:rerun-if-env-changed` annotations)
Failed merges:
r? @ghost
build: Remove unnecessary `cargo:rerun-if-env-changed` annotations
... and a couple of related cleanups.
rustc and cargo now track the majority of env var dependencies automatically (https://github.com/rust-lang/cargo/pull/8421), so the annotations are no longer necessary.
Enable perf try builder
This adds a dedicated branch for perf to use for CI, intended to allow perf to
enqueue builds without needing to use bors. bors is great, but bors requires an
open PR to work, and we want to invoke perf on closed PRs sometimes (in
particular, rollups).
Guard against non-monomorphized type_id intrinsic call
This PR checks whether the type is sufficient monomorphized when calling type_id or type_name intrinsics. If the type is not sufficiently monomorphized, e.g. used in a pattern, the code will be rejected.
Fixes#73976
rustdoc: Always warn when linking from public to private items
Change the logic such that linking from a public to a private item always triggers `intra_doc_link_resolution_failure`.
Previously, the warning was not emitted when `--document-private-items` is passed.
This came up during the discussion in https://github.com/rust-lang/rust/pull/74147#discussion_r452597901.
This commit improves codegen for unchecked casts on WebAssembly targets
to use the singluar `iNN.trunc_fMM_{u,s}` instructions. Previously rustc
would codegen a bare `fptosi` and `fptoui` for float casts but for
WebAssembly targets the codegen for these instructions is quite large.
This large codegen is due to the fact that LLVM can speculate these
instructions so the trapping behavior of WebAssembly needs to be
protected against in case they're speculated.
The change here is to update the codegen for the unchecked cast
intrinsics to have a wasm-specific case where they call the appropriate
LLVM intrinsic to generate the right wasm instruction. The intrinsic is
explicitly opting-in to undefined behavior so a trap here for
out-of-bounds inputs on wasm should be acceptable.
cc #73591
