Auto merge of #115228 - saethlin:is-interrupted, r=thomcc

Add a new helper to avoid calling io::Error::kind

On `cfg(unix)`, `Error::kind` emits an enormous jump table that LLVM seems unable to optimize out. I don't really understand why, but see for yourself: https://godbolt.org/z/17hY496KG

This change lets us check for `ErrorKind::Interrupted` without going through a big match. I've checked the codegen locally, and it has the desired effect on the codegen for `BufReader::read_exact`.

library/std/src/sys/itron/error.rs

@@ -79,6 +79,11 @@ pub fn error_name(er: abi::ER) -> Option<&'static str> {
     }
 }
 
+#[inline]
+pub fn is_interrupted(er: abi::ER) -> bool {
+    er == abi::E_RLWAI
+}
+
 pub fn decode_error_kind(er: abi::ER) -> ErrorKind {
     match er {
         // Success

library/std/src/sys/sgx/mod.rs

@@ -86,6 +86,12 @@ pub fn sgx_ineffective<T>(v: T) -> crate::io::Result<T> {
     }
 }
 
+#[inline]
+pub fn is_interrupted(code: i32) -> bool {
+    use fortanix_sgx_abi::Error;
+    code == Error::Interrupted as _
+}
+
 pub fn decode_error_kind(code: i32) -> ErrorKind {
     use fortanix_sgx_abi::Error;
 

library/std/src/sys/solid/error.rs

@@ -31,6 +31,11 @@ pub fn error_name(er: abi::ER) -> Option<&'static str> {
     }
 }
 
+#[inline]
+fn is_interrupted(er: abi::ER) -> bool {
+    false
+}
+
 pub fn decode_error_kind(er: abi::ER) -> ErrorKind {
     match er {
         // Success

library/std/src/sys/solid/mod.rs

@@ -72,6 +72,11 @@ pub fn unsupported_err() -> crate::io::Error {
     )
 }
 
+#[inline]
+pub fn is_interrupted(code: i32) -> bool {
+    error::is_interrupted(code)
+}
+
 pub fn decode_error_kind(code: i32) -> crate::io::ErrorKind {
     error::decode_error_kind(code)
 }

library/std/src/sys/solid/net.rs

@@ -181,6 +181,12 @@ pub(super) fn error_name(er: abi::ER) -> Option<&'static str> {
     unsafe { CStr::from_ptr(netc::strerror(er)) }.to_str().ok()
 }
 
+#[inline]
+pub fn is_interrupted(er: abi::ER) -> bool {
+    let errno = netc::SOLID_NET_ERR_BASE - er;
+    errno as libc::c_int == libc::EINTR
+}
+
 pub(super) fn decode_error_kind(er: abi::ER) -> ErrorKind {
     let errno = netc::SOLID_NET_ERR_BASE - er;
     match errno as libc::c_int {

library/std/src/sys/unix/mod.rs

@@ -240,6 +240,11 @@ pub use crate::sys::android::signal;
 #[cfg(not(target_os = "android"))]
 pub use libc::signal;
 
+#[inline]
+pub(crate) fn is_interrupted(errno: i32) -> bool {
+    errno == libc::EINTR
+}
+
 pub fn decode_error_kind(errno: i32) -> ErrorKind {
     use ErrorKind::*;
     match errno as libc::c_int {

library/std/src/sys/unsupported/common.rs

@@ -23,6 +23,10 @@ pub fn unsupported_err() -> std_io::Error {
     )
 }
 
+pub fn is_interrupted(_code: i32) -> bool {
+    false
+}
+
 pub fn decode_error_kind(_code: i32) -> crate::io::ErrorKind {
     crate::io::ErrorKind::Uncategorized
 }

library/std/src/sys/wasi/mod.rs

@@ -76,6 +76,11 @@ cfg_if::cfg_if! {
 mod common;
 pub use common::*;
 
+#[inline]
+pub fn is_interrupted(errno: i32) -> bool {
+    errno == wasi::ERRNO_INTR.raw().into()
+}
+
 pub fn decode_error_kind(errno: i32) -> std_io::ErrorKind {
     use std_io::ErrorKind::*;
     if errno > u16::MAX as i32 || errno < 0 {

library/std/src/sys/windows/mod.rs

@@ -60,6 +60,11 @@ pub unsafe fn cleanup() {
     net::cleanup();
 }
 
+#[inline]
+pub fn is_interrupted(_errno: i32) -> bool {
+    false
+}
+
 pub fn decode_error_kind(errno: i32) -> ErrorKind {
     use ErrorKind::*;