Add support for FreeBSD

[kkebo]

I've added support for FreeBSD. I've only tested this PR on FreeBSD, but I believe it should also work on OpenBSD.

Motivation:

closes #372

Also, Swift on FreeBSD preview toolchain is now available.

Modifications:

• changed pthread-related code for *BSD
• changed Glibc.stdout and Glibc.stderr for *BSD because they are non-optional on *BSD

Result:

swift-log and packages depending on it will be usable on FreeBSD.

Checks:

I tested it with swift build and swift test. All tests have passed.

$ swift test
...
Test Suite 'All tests' passed at 2025-11-07 04:29:34.003                                                                                         
         Executed 0 tests, with 0 failures (0 unexpected) in 0.0 (0.0) seconds
...
✔ Test run with 52 tests in 7 suites passed after 0.309 seconds.

Environment:

$ uname -a
FreeBSD Coconut-rhinoceros-beetle 15.0-BETA4 FreeBSD 15.0-BETA4 releng/15.0-n280841-a7707f2a3bf4 GENERIC amd64
$ swift --version
Swift version 6.3-dev (LLVM bff1370bd79c983, Swift 57cf4ce563f700b)
Target: x86_64-unknown-freebsd14.3
Build config: +assertions

Swift toolchain is from https://forums.swift.org/t/swift-on-freebsd-preview/83064.

[3405691582]

OpenBSD post 7.8 also needs the following changes, but otherwise swift-log compiles with this patch. Do you mind integrating this and rebasing?

diff --git a/Sources/Logging/Logging.swift b/Sources/Logging/Logging.swift
index a93b9a1..b3d897a 100644
--- a/Sources/Logging/Logging.swift
+++ b/Sources/Logging/Logging.swift
@@ -1312,7 +1312,7 @@ public struct MultiplexLogHandler: LogHandler {
     }
 }
 
-#if canImport(WASILibc) || os(Android)
+#if canImport(WASILibc) || os(Android) || os(OpenBSD)
 internal typealias CFilePointer = OpaquePointer
 #else
 internal typealias CFilePointer = UnsafeMutablePointer<FILE>
diff --git a/Tests/LoggingTests/TestLogger.swift b/Tests/LoggingTests/TestLogger.swift
index 7d6258a..fc77249 100644
--- a/Tests/LoggingTests/TestLogger.swift
+++ b/Tests/LoggingTests/TestLogger.swift
@@ -375,6 +375,10 @@ public class MDC {
         return Int(pthread_mach_thread_np(pthread_self()))
         #elseif os(Windows)
         return Int(GetCurrentThreadId())
+        #elseif os(FreeBSD)
+        return Int(pthread_getthreadid_np())
+        #elseif os(OpenBSD)
+        return Int(bitPattern: pthread_self())
         #else
         return Int(pthread_self())
         #endif

[kkebo]

Yes, sure.

[kkebo]

@3405691582 I've added those changes. Thank you for your suggestions!