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([2001:288:7001:2703:7ad0:37c7:5275:4b0]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-73698450244sm7620234b3a.80.2025.03.10.00.38.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Mar 2025 00:38:58 -0700 (PDT) From: I Hsin Cheng To: ojeda@kernel.org Cc: alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linux.dev, jserv@ccns.ncku.edu.tw, I Hsin Cheng Subject: [PATCH] rust: list: Use "List::is_empty()" to perform checking when possible Date: Mon, 10 Mar 2025 15:38:52 +0800 Message-ID: <20250310073853.427954-1-richard120310@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit "List::is_empty()" provides a straight forward convention to check whether a given "List" is empty or not. There're numerous places in the current implementation still use "self.first.is_null()" to perform the equivalent check, replace them with "List::is_empty()". Signed-off-by: I Hsin Cheng --- rust/kernel/list.rs | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/rust/kernel/list.rs b/rust/kernel/list.rs index fb93330f4af4..8f3919bd3f99 100644 --- a/rust/kernel/list.rs +++ b/rust/kernel/list.rs @@ -259,7 +259,7 @@ pub fn push_back(&mut self, item: ListArc) { // SAFETY: We have not yet called `post_remove`, so `list_links` is still valid. let item = unsafe { ListLinks::fields(list_links) }; - if self.first.is_null() { + if self.is_empty() { self.first = item; // SAFETY: The caller just gave us ownership of these fields. // INVARIANT: A linked list with one item should be cyclic. @@ -299,7 +299,7 @@ pub fn push_front(&mut self, item: ListArc) { // SAFETY: We have not yet called `post_remove`, so `list_links` is still valid. let item = unsafe { ListLinks::fields(list_links) }; - if self.first.is_null() { + if self.is_empty() { // SAFETY: The caller just gave us ownership of these fields. // INVARIANT: A linked list with one item should be cyclic. unsafe { @@ -325,7 +325,7 @@ pub fn push_front(&mut self, item: ListArc) { /// Removes the last item from this list. pub fn pop_back(&mut self) -> Option> { - if self.first.is_null() { + if self.is_empty() { return None; } @@ -337,7 +337,7 @@ pub fn pop_back(&mut self) -> Option> { /// Removes the first item from this list. pub fn pop_front(&mut self) -> Option> { - if self.first.is_null() { + if self.is_empty() { return None; } @@ -493,7 +493,7 @@ pub fn push_all_back(&mut self, other: &mut List) { /// /// If the list is empty, this returns `None`. pub fn cursor_front(&mut self) -> Option> { - if self.first.is_null() { + if self.is_empty() { None } else { Some(Cursor { -- 2.43.0