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| author | Trevor Gross <t.gross35@gmail.com> | 2024-09-30 19:18:50 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-09-30 19:18:50 -0400 |
| commit | 2fe41869c9eea690d3bd94e3de094282ccb7645c (patch) | |
| tree | 87487a5b996befc18e8b1fbe58b2fab2a5804e23 | |
| parent | acaa6cee0754b9a8134e6aa1aa2b28c2670eb20e (diff) | |
| parent | 24290efafffb83514da4e37f5f42a962d0e9bb1f (diff) | |
| download | rust-2fe41869c9eea690d3bd94e3de094282ccb7645c.tar.gz rust-2fe41869c9eea690d3bd94e3de094282ccb7645c.zip | |
Rollup merge of #130914 - compiler-errors:insignificant-dtor, r=Amanieu
Mark some more types as having insignificant dtor These were caught by https://github.com/rust-lang/rust/pull/129864#issuecomment-2376658407, which is implementing a lint for some changes in drop order for temporaries in tail expressions. Specifically, the destructors of `CString` and the bitpacked repr for `std::io::Error` are insignificant insofar as they don't have side-effects on things like locking or synchronization; they just free memory. See some discussion on #89144 for what makes a drop impl "significant"
| -rw-r--r-- | library/alloc/src/boxed.rs | 1 | ||||
| -rw-r--r-- | library/alloc/src/ffi/c_str.rs | 1 | ||||
| -rw-r--r-- | library/alloc/src/sync.rs | 1 | ||||
| -rw-r--r-- | library/std/src/io/error/repr_bitpacked.rs | 1 |
4 files changed, 4 insertions, 0 deletions
diff --git a/library/alloc/src/boxed.rs b/library/alloc/src/boxed.rs index 6421504b896..5f207295683 100644 --- a/library/alloc/src/boxed.rs +++ b/library/alloc/src/boxed.rs @@ -228,6 +228,7 @@ mod thin; #[lang = "owned_box"] #[fundamental] #[stable(feature = "rust1", since = "1.0.0")] +#[rustc_insignificant_dtor] // The declaration of the `Box` struct must be kept in sync with the // compiler or ICEs will happen. pub struct Box< diff --git a/library/alloc/src/ffi/c_str.rs b/library/alloc/src/ffi/c_str.rs index 797d591a8b5..d496899e72b 100644 --- a/library/alloc/src/ffi/c_str.rs +++ b/library/alloc/src/ffi/c_str.rs @@ -696,6 +696,7 @@ impl CString { // memory-unsafe code from working by accident. Inline // to prevent LLVM from optimizing it away in debug builds. #[stable(feature = "cstring_drop", since = "1.13.0")] +#[rustc_insignificant_dtor] impl Drop for CString { #[inline] fn drop(&mut self) { diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs index ced789c4f92..5d099a49854 100644 --- a/library/alloc/src/sync.rs +++ b/library/alloc/src/sync.rs @@ -237,6 +237,7 @@ macro_rules! acquire { /// [rc_examples]: crate::rc#examples #[cfg_attr(not(test), rustc_diagnostic_item = "Arc")] #[stable(feature = "rust1", since = "1.0.0")] +#[rustc_insignificant_dtor] pub struct Arc< T: ?Sized, #[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global, diff --git a/library/std/src/io/error/repr_bitpacked.rs b/library/std/src/io/error/repr_bitpacked.rs index 80ba8455df3..a839a2fbac1 100644 --- a/library/std/src/io/error/repr_bitpacked.rs +++ b/library/std/src/io/error/repr_bitpacked.rs @@ -124,6 +124,7 @@ const TAG_SIMPLE: usize = 0b11; /// is_unwind_safe::<std::io::Error>(); /// ``` #[repr(transparent)] +#[rustc_insignificant_dtor] pub(super) struct Repr(NonNull<()>, PhantomData<ErrorData<Box<Custom>>>); // All the types `Repr` stores internally are Send + Sync, and so is it. |