From 814697e4af04996e12fec57c75ebcb296a1478d6 Mon Sep 17 00:00:00 2001
From: Luke Howard <lukeh@padl.com>
Date: Fri, 17 May 2024 17:01:17 +0200
Subject: [PATCH] correctly handle functions which return global errno

---
 Sources/IORing/Message.swift         |  3 ++-
 Sources/IORingUtils/Extensions.swift | 15 ++++++++++++---
 Sources/IORingUtils/Socket.swift     | 10 +++++-----
 Sources/IORingUtils/Tty.swift        |  6 +++---
 4 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/Sources/IORing/Message.swift b/Sources/IORing/Message.swift
index be491f0..3f202dd 100644
--- a/Sources/IORing/Message.swift
+++ b/Sources/IORing/Message.swift
@@ -24,7 +24,8 @@ import CIOURing
 import Glibc
 import SystemPackage
 
-extension msghdr: @unchecked Sendable {}
+extension msghdr: @unchecked
+Sendable {}
 
 public struct Control {
   public var level: Int32
diff --git a/Sources/IORingUtils/Extensions.swift b/Sources/IORingUtils/Extensions.swift
index d2ecbbf..453d39b 100644
--- a/Sources/IORingUtils/Extensions.swift
+++ b/Sources/IORingUtils/Extensions.swift
@@ -101,14 +101,14 @@ extension IORing {
 
 public extension FileDescriptorRepresentable {
   func set(flags: Int32, mask: Int32) throws {
-    var flags = try Errno.throwingErrno { fcntl(self.fileDescriptor, F_GETFL, 0) }
+    var flags = try Errno.throwingGlobalErrno { fcntl(self.fileDescriptor, F_GETFL, 0) }
     flags &= ~mask
     flags |= mask
-    try Errno.throwingErrno { fcntl(self.fileDescriptor, F_SETFL, flags) }
+    try Errno.throwingGlobalErrno { fcntl(self.fileDescriptor, F_SETFL, flags) }
   }
 
   func get(flag: Int32) throws -> Bool {
-    let flags = try Errno.throwingErrno { fcntl(self.fileDescriptor, F_GETFL, 0) }
+    let flags = try Errno.throwingGlobalErrno { fcntl(self.fileDescriptor, F_GETFL, 0) }
     return flags & flag != 0
   }
 
@@ -143,4 +143,13 @@ public extension FileDescriptorRepresentable {
 
 extension Errno {
   static var lastError: Errno { Errno(rawValue: errno) }
+
+  @discardableResult
+  static func throwingGlobalErrno(_ body: @escaping () -> CInt) throws -> CInt {
+    let result = body()
+    if result < 0 {
+      throw Errno(rawValue: errno)
+    }
+    return result
+  }
 }
diff --git a/Sources/IORingUtils/Socket.swift b/Sources/IORingUtils/Socket.swift
index 150fba0..ecef94d 100644
--- a/Sources/IORingUtils/Socket.swift
+++ b/Sources/IORingUtils/Socket.swift
@@ -66,7 +66,7 @@ public struct Socket: CustomStringConvertible, Equatable, Hashable, Sendable {
 
     _ = try withUnsafeMutablePointer(to: &ss) { pointer in
       try pointer.withMemoryRebound(to: sockaddr.self, capacity: 1) { sa in
-        try Errno.throwingErrno {
+        try Errno.throwingGlobalErrno {
           body(fileHandle.fileDescriptor, sa, &length)
         }
       }
@@ -102,7 +102,7 @@ public struct Socket: CustomStringConvertible, Equatable, Hashable, Sendable {
   public func setBooleanOption(level: CInt = SOL_SOCKET, option: CInt, to value: Bool) throws {
     guard let fileHandle else { throw Errno.badFileDescriptor }
     var value: CInt = value ? 1 : 0
-    try Errno.throwingErrno { setsockopt(
+    try Errno.throwingGlobalErrno { setsockopt(
       fileHandle.fileDescriptor,
       level,
       option,
@@ -148,7 +148,7 @@ public struct Socket: CustomStringConvertible, Equatable, Hashable, Sendable {
   public func bind(to address: any SocketAddress) throws {
     guard let fileHandle else { throw Errno.badFileDescriptor }
     _ = try address.withSockAddr { sa in
-      try Errno.throwingErrno {
+      try Errno.throwingGlobalErrno {
         SwiftGlibc.bind(fileHandle.fileDescriptor, sa, address.size)
       }
     }
@@ -156,7 +156,7 @@ public struct Socket: CustomStringConvertible, Equatable, Hashable, Sendable {
 
   public func listen(backlog: Int = 128) throws {
     guard let fileHandle else { throw Errno.badFileDescriptor }
-    _ = try Errno.throwingErrno {
+    _ = try Errno.throwingGlobalErrno {
       SwiftGlibc.listen(fileHandle.fileDescriptor, Int32(backlog))
     }
   }
@@ -182,7 +182,7 @@ public struct Socket: CustomStringConvertible, Equatable, Hashable, Sendable {
     guard let fileHandle else { throw Errno.badFileDescriptor }
     try fileHandle.setBlocking(false)
     _ = try address.withSockAddr { sa in
-      try Errno.throwingErrno {
+      try Errno.throwingGlobalErrno {
         SwiftGlibc.connect(fileHandle.fileDescriptor, sa, address.size)
       }
     }
diff --git a/Sources/IORingUtils/Tty.swift b/Sources/IORingUtils/Tty.swift
index 351d0ce..3ab9e0c 100644
--- a/Sources/IORingUtils/Tty.swift
+++ b/Sources/IORingUtils/Tty.swift
@@ -49,7 +49,7 @@ public extension termios {
 
   mutating func set(speed: UInt32) throws {
     var tty = self
-    try Errno.throwingErrno {
+    try Errno.throwingGlobalErrno {
       cfsetspeed(&tty, speed)
     }
     self = tty
@@ -89,14 +89,14 @@ public extension termios {
 public extension FileDescriptorRepresentable {
   func set(tty: termios) throws {
     var tty = tty
-    try Errno.throwingErrno {
+    try Errno.throwingGlobalErrno {
       tcsetattr(self.fileDescriptor, TCSANOW, &tty)
     }
   }
 
   func getTty() throws -> termios {
     var tty = termios()
-    try Errno.throwingErrno {
+    try Errno.throwingGlobalErrno {
       tcgetattr(self.fileDescriptor, &tty)
     }
     return tty