From 38591d2d77c9fadf4d199ec6a6e937ec80d1796d Mon Sep 17 00:00:00 2001
From: Alice Ryhl <aliceryhl@google.com>
Date: Thu, 16 Jul 2026 07:05:06 +0000
Subject: [PATCH] Add #[inline] to core::io methods with simple logic or
 forwarding

---
 library/core/src/io/error.rs                     | 8 ++++++++
 library/core/src/io/error/os_functions_atomic.rs | 1 +
 library/core/src/io/error/repr_bitpacked.rs      | 1 +
 library/core/src/io/io_slice.rs                  | 2 ++
 library/core/src/net/ip_addr.rs                  | 1 +
 5 files changed, 13 insertions(+)

diff --git a/library/core/src/io/error.rs b/library/core/src/io/error.rs
index 61abdb16d07da..0df8b2d05cf48 100644
--- a/library/core/src/io/error.rs
+++ b/library/core/src/io/error.rs
@@ -534,6 +534,7 @@ impl fmt::Display for Error {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl error::Error for Error {
     #[allow(deprecated)]
+    #[inline]
     fn cause(&self) -> Option<&dyn error::Error> {
         match self.repr.data() {
             ErrorData::Os(..) => None,
@@ -543,6 +544,7 @@ impl error::Error for Error {
         }
     }
 
+    #[inline]
     fn source(&self) -> Option<&(dyn error::Error + 'static)> {
         match self.repr.data() {
             ErrorData::Os(..) => None,
@@ -605,6 +607,7 @@ impl fmt::Debug for Custom {
 
 #[unstable(feature = "core_io_internals", reason = "exposed only for libstd", issue = "none")]
 impl Drop for Custom {
+    #[inline]
     fn drop(&mut self) {
         // SAFETY: `Custom::from_raw` ensures this call is safe.
         unsafe {
@@ -631,12 +634,14 @@ impl Custom {
     }
 
     #[unstable(feature = "core_io_internals", reason = "exposed only for libstd", issue = "none")]
+    #[inline]
     pub fn into_raw(self) -> crate::ptr::NonNull<dyn error::Error + Send + Sync> {
         let ptr = self.error;
         core::mem::forget(self);
         ptr
     }
 
+    #[inline]
     fn error_ref(&self) -> &(dyn error::Error + Send + Sync + 'static) {
         // SAFETY:
         // `from_raw` ensures `error` is a valid pointer up to a static lifetime
@@ -644,6 +649,7 @@ impl Custom {
         unsafe { self.error.as_ref() }
     }
 
+    #[inline]
     fn error_mut(&mut self) -> &mut (dyn error::Error + Send + Sync + 'static) {
         // SAFETY:
         // `from_raw` ensures `error` is a valid pointer up to a static lifetime
@@ -668,6 +674,7 @@ unsafe impl Sync for CustomOwner {}
 
 #[unstable(feature = "core_io_internals", reason = "exposed only for libstd", issue = "none")]
 impl Drop for CustomOwner {
+    #[inline]
     fn drop(&mut self) {
         // SAFETY: `CustomOwner::from_raw` ensures this call is safe.
         unsafe {
@@ -687,6 +694,7 @@ impl CustomOwner {
     }
 
     #[unstable(feature = "core_io_internals", reason = "exposed only for libstd", issue = "none")]
+    #[inline]
     pub fn into_raw(self) -> crate::ptr::NonNull<Custom> {
         let ptr = self.0;
         core::mem::forget(self);
diff --git a/library/core/src/io/error/os_functions_atomic.rs b/library/core/src/io/error/os_functions_atomic.rs
index dfaf59ae742de..d4d77ced59187 100644
--- a/library/core/src/io/error/os_functions_atomic.rs
+++ b/library/core/src/io/error/os_functions_atomic.rs
@@ -15,6 +15,7 @@ use crate::sync::atomic;
 static OS_FUNCTIONS: atomic::AtomicPtr<OsFunctions> =
     atomic::AtomicPtr::new(OsFunctions::DEFAULT as *const _ as *mut _);
 
+#[inline]
 fn get_os_functions() -> &'static OsFunctions {
     // SAFETY:
     //  * `OS_FUNCTIONS` is initially a pointer to `OsFunctions::DEFAULT`, which is valid for a static lifetime.
diff --git a/library/core/src/io/error/repr_bitpacked.rs b/library/core/src/io/error/repr_bitpacked.rs
index 22cb331924081..8758e5543762a 100644
--- a/library/core/src/io/error/repr_bitpacked.rs
+++ b/library/core/src/io/error/repr_bitpacked.rs
@@ -133,6 +133,7 @@ unsafe impl Send for Repr {}
 unsafe impl Sync for Repr {}
 
 impl Repr {
+    #[inline]
     pub(super) fn new_custom(b: CustomOwner) -> Self {
         let p = b.into_raw().as_ptr().cast::<u8>();
         // Should only be possible if an allocator handed out a pointer with
diff --git a/library/core/src/io/io_slice.rs b/library/core/src/io/io_slice.rs
index 0bdd410d3e964..807bbfcd36225 100644
--- a/library/core/src/io/io_slice.rs
+++ b/library/core/src/io/io_slice.rs
@@ -155,6 +155,7 @@ impl<'a> IoSliceMut<'a> {
     /// assert_eq!(&data, b"Abcdef");
     /// ```
     #[unstable(feature = "io_slice_as_bytes", issue = "132818")]
+    #[inline]
     pub const fn into_slice(self) -> &'a mut [u8] {
         self.0.into_slice()
     }
@@ -323,6 +324,7 @@ impl<'a> IoSlice<'a> {
     /// assert_eq!(io_slice.as_slice(), b"def");
     /// ```
     #[unstable(feature = "io_slice_as_bytes", issue = "132818")]
+    #[inline]
     pub const fn as_slice(self) -> &'a [u8] {
         self.0.as_slice()
     }
diff --git a/library/core/src/net/ip_addr.rs b/library/core/src/net/ip_addr.rs
index 4e380a93972e7..3fe98eba22358 100644
--- a/library/core/src/net/ip_addr.rs
+++ b/library/core/src/net/ip_addr.rs
@@ -2480,6 +2480,7 @@ macro_rules! bitop_impls {
 
             $(#[$attr])*
             const impl $BitOpAssign<&'_ $ty> for $ty {
+                #[inline]
                 fn $bitop_assign(&mut self, rhs: &'_ $ty) {
                     self.$bitop_assign(*rhs);
                 }