Fix building on Windows

Author: stevapple

Package.swift

@@ -12,11 +12,19 @@
 
 import PackageDescription
 
-let targets: [PackageDescription.Target] = [
+var windowsPlatform: [Platform] = []
+#if os(Windows)
+windowsPlatform.append(.windows)
+#endif
+
+let targets: [Target] = [
   .target(
     name: "SystemPackage",
     dependencies: ["CSystem"],
     path: "Sources/System",
+    cSettings: [
+      .define("_CRT_SECURE_NO_WARNINGS", .when(platforms: windowsPlatform)),
+    ],
     swiftSettings: [
       .define("SYSTEM_PACKAGE"),
       .define("ENABLE_MOCKING", .when(configuration: .debug))

Sources/System/Internals/Mocking.swift

@@ -146,7 +146,7 @@ private func originalSyscallName(_ function: String) -> String {
 
 private func mockImpl(
   name: String,
-  path: UnsafePointer<CChar>?,
+  path: UnsafePointer<CInterop.PlatformChar>?,
   _ args: [AnyHashable]
 ) -> CInt {
   precondition(mockingEnabled)
@@ -177,18 +177,18 @@ private func mockImpl(
 }
 
 internal func _mock(
-  name: String = #function, path: UnsafePointer<CChar>? = nil, _ args: AnyHashable...
+  name: String = #function, path: UnsafePointer<CInterop.PlatformChar>? = nil, _ args: AnyHashable...
 ) -> CInt {
   return mockImpl(name: name, path: path, args)
 }
 internal func _mockInt(
-  name: String = #function, path: UnsafePointer<CChar>? = nil, _ args: AnyHashable...
+  name: String = #function, path: UnsafePointer<CInterop.PlatformChar>? = nil, _ args: AnyHashable...
 ) -> Int {
   Int(mockImpl(name: name, path: path, args))
 }
 
 internal func _mockOffT(
-  name: String = #function, path: UnsafePointer<CChar>? = nil, _ args: AnyHashable...
+  name: String = #function, path: UnsafePointer<CInterop.PlatformChar>? = nil, _ args: AnyHashable...
 ) -> _COffT {
   _COffT(mockImpl(name: name, path: path, args))
 }