uninit_vec: fix false positive with set_len(0) #9519
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Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @llogiq (or someone else) soon. Please see the contribution instructions for more information. |
rust-highfive
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clippy_lints/src/uninit_vec.rs
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| @@ -211,9 +212,12 @@ fn extract_set_len_self<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'_>) -> Opt | |||
| } | |||
| }); | |||
| match expr.kind { | |||
| ExprKind::MethodCall(path, self_expr, [_], _) => { | |||
| ExprKind::MethodCall(path, self_expr, args, _) => { | |||
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| ExprKind::MethodCall(path, self_expr, args, _) => { | |
| ExprKind::MethodCall(path, self_expr, [arg], _) => { |
You can match the single arg directly, because all set_len calls have exactly one argument. This will save you an if let in is_literal_zero.
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Thank you for the PR. I have only a very small style suggestion, otherwise this looks mergeworthy. |
set_len(0) does not create uninitialized elements. Fixes a false positive with
the following pattern:
fn copy_slice_into_vec(dst: &mut Vec<u8>, src: &[u8]) {
dst.reserve(src.len().saturating_sub(dst.len()));
unsafe {
dst.set_len(0);
std::ptr::copy_nonoverlapping(src.as_ptr(), dst.as_mut_ptr(), src.len());
dst.set_len(src.len());
}
}
alessandrod
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Thanks for reviewing! |
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Thank you! @bors r+ |
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☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test |
set_len(0)does not create uninitialized elements. Fixes a false positive with the following pattern:zulip thread: https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/uninit_vec.20and.20set_len.280.29
changelog: FP: [
uninit_vec]: No longer lintsVec::set_len(0)