[CoreFoundation][Foundation][Tools] Miscellanous musl support.

This is mostly checking for and importing the `Musl` module and,
where necessary, using it instead of the `Glibc` module.

rdar://123381867

Author: al45tair

CoreFoundation/Base.subproj/CFUtilities.c

@@ -1675,7 +1675,7 @@ CFDictionaryRef __CFGetEnvironment() {
         extern char **environ;
         char **envp = environ;
 #elif TARGET_OS_LINUX
-#if !defined(environ) && !TARGET_OS_ANDROID
+#if !defined(environ) && !TARGET_OS_ANDROID && !defined(__musl__)
 #define environ __environ
 #endif
         char **envp = environ;

Sources/Foundation/Data.swift

@@ -28,6 +28,13 @@
 @usableFromInline let memset = Glibc.memset
 @usableFromInline let memcpy = Glibc.memcpy
 @usableFromInline let memcmp = Glibc.memcmp
+#elseif canImport(Musl)
+@usableFromInline let calloc = Musl.calloc
+@usableFromInline let malloc = Musl.malloc
+@usableFromInline let free = Musl.free
+@usableFromInline let memset = Musl.memset
+@usableFromInline let memcpy = Musl.memcpy
+@usableFromInline let memcmp = Musl.memcmp
 #elseif canImport(WASILibc)
 @usableFromInline let calloc = WASILibc.calloc
 @usableFromInline let malloc = WASILibc.malloc
@@ -48,6 +55,8 @@ internal func malloc_good_size(_ size: Int) -> Int {
 
 #if canImport(Glibc)
 import Glibc
+#elseif canImport(Musl)
+import Musl
 #elseif canImport(WASILibc)
 import WASILibc
 #endif

Sources/Foundation/FileHandle.swift

@@ -22,6 +22,11 @@ import Glibc
 fileprivate let _read = Glibc.read(_:_:_:)
 fileprivate let _write = Glibc.write(_:_:_:)
 fileprivate let _close = Glibc.close(_:)
+#elseif canImport(Musl)
+import Musl
+fileprivate let _read = Musl.read(_:_:_:)
+fileprivate let _write = Musl.write(_:_:_:)
+fileprivate let _close = Musl.close(_:)
 #endif
 
 #if canImport(WinSDK)

Sources/Foundation/Host.swift

@@ -281,7 +281,7 @@ open class Host: NSObject {
             }
             var hints = addrinfo()
             hints.ai_family = PF_UNSPEC
-#if os(macOS) || os(iOS) || os(Android) || os(OpenBSD)
+#if os(macOS) || os(iOS) || os(Android) || os(OpenBSD) || canImport(Musl)
             hints.ai_socktype = SOCK_STREAM
 #else
             hints.ai_socktype = Int32(SOCK_STREAM.rawValue)

Sources/Foundation/NSData.swift

@@ -494,8 +494,10 @@ open class NSData : NSObject, NSCopying, NSMutableCopying, NSSecureCoding {
             let createMode = Int(ucrt.S_IREAD) | Int(ucrt.S_IWRITE)
 #elseif canImport(Darwin)
             let createMode = Int(S_IRUSR) | Int(S_IWUSR) | Int(S_IRGRP) | Int(S_IWGRP) | Int(S_IROTH) | Int(S_IWOTH)
-#else
+#elseif canImport(Glibc)
             let createMode = Int(Glibc.S_IRUSR) | Int(Glibc.S_IWUSR) | Int(Glibc.S_IRGRP) | Int(Glibc.S_IWGRP) | Int(Glibc.S_IROTH) | Int(Glibc.S_IWOTH)
+#elseif canImport(Musl)
+            let createMode = Int(Musl.S_IRUSR) | Int(Musl.S_IWUSR) | Int(Musl.S_IRGRP) | Int(Musl.S_IWGRP) | Int(Musl.S_IROTH) | Int(Musl.S_IWOTH)
 #endif
             guard let fh = FileHandle(path: path, flags: flags, createMode: createMode) else {
                 throw _NSErrorWithErrno(errno, reading: false, path: path)

Sources/Foundation/NSSwiftRuntime.swift

@@ -14,8 +14,10 @@
 // This mimics the behavior of the swift sdk overlay on Darwin
 #if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
 @_exported import Darwin
-#elseif os(Linux) || os(Android) || CYGWIN || os(OpenBSD)
+#elseif canImport(Glibc)
 @_exported import Glibc
+#elseif canImport(Musl)
+@_exported import Musl
 #elseif os(WASI)
 @_exported import WASILibc
 #elseif os(Windows)

Sources/Foundation/NSURL.swift

@@ -20,6 +20,8 @@ internal let kCFURLWindowsPathStyle = CFURLPathStyle.cfurlWindowsPathStyle
 import Darwin
 #elseif canImport(Glibc)
 import Glibc
+#elseif canImport(Musl)
+import Musl
 #endif
 
 // NOTE: this represents PLATFORM_PATH_STYLE

Sources/Foundation/Process.swift

@@ -776,7 +776,7 @@ open class Process: NSObject {
         }
 
         var taskSocketPair : [Int32] = [0, 0]
-#if os(macOS) || os(iOS) || os(Android) || os(OpenBSD)
+#if os(macOS) || os(iOS) || os(Android) || os(OpenBSD) || canImport(Musl)
         socketpair(AF_UNIX, SOCK_STREAM, 0, &taskSocketPair)
 #else
         socketpair(AF_UNIX, Int32(SOCK_STREAM.rawValue), 0, &taskSocketPair)

Sources/Foundation/Thread.swift

@@ -14,6 +14,8 @@ import WinSDK
 
 #if canImport(Glibc)
 import Glibc
+#elseif canImport(Musl)
+import Musl
 #endif
 
 // WORKAROUND_SR9811
@@ -356,13 +358,15 @@ open class Thread : NSObject {
         _cancelled = true
     }
 
+    // ###TODO: Switch these over to using the Swift runtime's backtracer
+    //          once we have Windows support there.
 
     private class func backtraceAddresses<T>(_ body: (UnsafeMutablePointer<UnsafeMutableRawPointer?>, Int) -> [T]) -> [T] {
         // Same as swift/stdlib/public/runtime/Errors.cpp backtrace
         let maxSupportedStackDepth = 128;
         let addrs = UnsafeMutablePointer<UnsafeMutableRawPointer?>.allocate(capacity: maxSupportedStackDepth)
         defer { addrs.deallocate() }
-#if os(Android) || os(OpenBSD)
+#if os(Android) || os(OpenBSD) || canImport(Musl)
         let count = 0
 #elseif os(Windows)
         let count = RtlCaptureStackBackTrace(0, DWORD(maxSupportedStackDepth),
@@ -383,7 +387,7 @@ open class Thread : NSObject {
     }
 
     open class var callStackSymbols: [String] {
-#if os(Android) || os(OpenBSD)
+#if os(Android) || os(OpenBSD) || canImport(Musl)
         return []
 #elseif os(Windows)
         let hProcess: HANDLE = GetCurrentProcess()

Sources/Tools/plutil/main.swift

@@ -12,6 +12,9 @@ import SwiftFoundation
 #elseif canImport(Glibc)
 import Foundation
 import Glibc
+#elseif canImport(Musl)
+import Foundation
+import Musl
 #elseif canImport(CRT)
 import Foundation
 import CRT