Upgrading to Swift 4.

Package.swift

@@ -1,5 +1,29 @@
+// swift-tools-version:4.0
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
 import PackageDescription
 
 let package = Package(
-    name: "CSwift"
+    name: "CSwift",
+    products: [
+        // Products define the executables and libraries produced by a package, and make them visible to other packages.
+        .library(
+            name: "CSwift",
+            type: .`dynamic`, 
+            targets: ["CSwift"]),
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        // .package(url: /* package url */, from: "1.0.0"),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+        .target(
+            name: "CSwift",
+            dependencies: []),
+        .testTarget(
+            name: "CSwiftTests",
+            dependencies: ["CSwift"]),
+    ]
 )

README.md

@@ -2,6 +2,8 @@
 
 Rockford Wei，2017-01-17
 
+Last update: 2018-01-23
+
 This project demonstrates how to call a customized C library in your swift project.
 You can clone it from github, or follow the instruction below to generate it step by step.
 
@@ -14,7 +16,7 @@ There are two C files: CSwift.c and CSwift.h. The objective is to build a CSwift
 
 ## Quick Start
 
-Please compile this project with Swift 3.0 toolchain.
+Please compile this project with Swift 4.0.3 toolchain.
 
 ### Build & Test
 
@@ -36,87 +38,60 @@ However, even without the sources above, you can still start everything from bla
 Assume the objective library is still CSwift, then find an empty folder and try these commands in a terminal:
 
 ```
-$ mkdir CSwift
-$ cd CSwift
-$ swift package init --type=system-module
-$ mkdir CSwift
-$ cd CSwift
-$ swift package init
-$ mv Tests ..
-$ mkdir include
-$ mv ../module.modulemap inlcude/
-$ rm Package.swift
-$ rm -rf Sources
-$ echo > CSwift.c
-$ echo > include/CSwift.h
-$ cd ..
-```
-
-You may notice that the above commands make a second CSwift folder inside the first one, but with different `swift package` commmand line.
-The first `swift package` is to create a blank swift project and will build as an system module; The second one, however, is just to create a common swift library.
-The purpose of such a trick is to create testing scripts for system module.
-
-Besides, it also creates an `include` folder under the second CSwift directory, with two blank source file place holder `CSwift.c` and `CSwift.h`.
-
-### Module Map
-
-Now it is time to modify the module map file, check this out:
-
-``` swift
-module CSwift [system] {
-  header "CSwift.h"
-  link "CSwift"
-  export *
-}
+mkdir CSwift && cd CSwift && swift package init
+mkdir Sources/CSwift/include && rm Sources/CSwift/CSwift.swift
 ```
 
-### C Code
+The above commands will set up the empty project template
 
-Then you can customize the C code as demo below:
+### C Header File
 
-#### CSwift/CSwift/include/CSwift.h
+Now edit the header file `Sources/CSwift/include/Swift.h`:
 
 ``` c
 extern int c_add(int, int);
 #define C_TEN 10
 ```
 
-#### CSwift/CSwift/CSwift.c
+### C Source
+
+Finishing the implementation of the C body `Sources/CSwift/CSwift.c`:
 
 ``` c
 #include "include/CSwift.h"
 int c_add(int a, int b) { return a + b ; }
 ```
 
-Up to now, C api is ready to call. So far so good.
+### Module Map
+
+Next, we will setup an umbrella file for swift: 
+`Sources/CSwift/include/module.modulemap`
+
+``` swift
+module CSwift [system] {
+  header "CSwift.h"
+  export *
+}
+```
 
 ### Call C API in Swift
 
-The following code is a good example to show how to call your C api statically, as `Tests/CSwiftTests/CSwiftTests.swift`:
+Now let's check if the library works by editing a test script:
+`Tests/CSwiftTests/CSwiftTests.swift`
 
 ``` swift
-
 import XCTest
 @testable import CSwift
-
 class CSwiftTests: XCTestCase {
-    func testExample() {
-        // Test call "x + y" from your C library
-        let three = c_add(1, 2)
-        XCTAssertEqual(three, 3)
-
-        // Test macro exports
-        XCTAssertEqual(C_TEN, 10)
-    }
-
-
-    static var allTests : [(String, (CSwiftTests) -> () throws -> Void)] {
-        return [
-            ("testExample", testExample),
-        ]
-    }
+  func testExample() {
+    let three = c_add(1, 2)
+    XCTAssertEqual(three, 3)
+    XCTAssertEqual(C_TEN, 10)
+  }
+  static var allTests : [(String, (CSwiftTests) -> () throws -> Void)] {
+      return [  ("testExample", testExample)  ]
+  }
 }
-
 ```
 
 ### Test
@@ -137,6 +112,17 @@ This project also makes an example for swift script, and even more, introduces h
 
 ### Dynamic Link Library
 
+The default linking object of Swift 4 is static, so it needs a bit modification to turn it into a dynamic one. 
+
+To do this, edit the Package.swift file, and add a line:
+
+``` swift
+.library(
+    name: "CSwift",
+    type: .`dynamic`,  // <------------ Insert the dynamic type right here!
+    targets: ["CSwift"]),
+```
+
 Please check a swift script `dll.swift.script`, actually it is a common swift with no difference to any other swift sources:
 
 ``` swift

README.zh_CN.md

@@ -1,7 +1,9 @@
-# Swift 调用 C 语言自建函数库 及 Swift 脚本和动态链接库的使用方法 [English](README.md)
+# Swift 调用 C 语言自建函数库 及 Swift 脚本和动态链接库的使用方法 
 
 Rockford Wei，2017-01-17
 
+最近更新：2018-01-23
+
 本程序示范了如何用Swift调用自定义C语言模块的方法。您可以直接下载本程序，或者按照以下教程逐步完成。
 此外，示范程序还展示了如何使用 Swift 作为脚本运行，并且在脚本中调用C语言的动态链接库，使得服务器端Swift 开发实现热补丁。
 
@@ -11,7 +13,7 @@ Rockford Wei，2017-01-17
 
 ## 快速上手
 
-本程序需要Swift 3.0以上版本。
+本程序需要Swift 4.0.3 以上版本。
 
 ### 下载、编译和测试
 
@@ -32,55 +34,41 @@ $ swift test
 仍然假定函数库名称为CSwift。首先找一个空白目录，然后执行：
 
 ```
-$ mkdir CSwift
-$ cd CSwift
-$ swift package init --type=system-module
-$ mkdir CSwift
-$ cd CSwift
-$ swift package init
-$ mv Tests ..
-$ mkdir include
-$ mv ../module.modulemap include/
-$ rm Package.swift
-$ rm -rf Sources
-$ echo > CSwift.c
-$ echo > include/CSwift.h
-$ cd ..
-```
-
-细心的读者会发现，上面的bash 命令行在CSwift 文件夹下面建立了第二个CSwift文件夹，但是使用了不同的`swift package`了命令。第一个命令是“创建swift空白项目，而且项目类型是系统模块”；而第二个命令是“创建swift 空白项目，项目类型是函数库”。这种做法主要是为了能够在同一个项目中用Swift去测试C语言的模块。其次，在第二个CSwift 子目录下，还建立了一个include 文件夹，并分别建立了两个空白源程序文件 CSwift.c 和 CSwift.h
-
-### Module Map
-
-下一步是修理一下目标的模块映射表。请把module.modulemap修改为如下程序：
-
-``` swift
-module CSwift [system] {
-  header "CSwift.h"
-  link "CSwift"
-  export *
-}
+mkdir CSwift && cd CSwift && swift package init
+mkdir Sources/CSwift/include && rm Sources/CSwift/CSwift.swift
 ```
 
-### C模块编程
+上述命令能够新建一个空白的函数库模板
 
-好了，现在请编辑刚才在第二个CSwift文件夹下面的建立两个C语言文件：CSwift.c和CSwift.h，内容如下：
+### C 函数头文件
 
-#### CSwift/CSwift/include/CSwift.h
+现在编辑头文件 `Sources/CSwift/include/Swift.h`:
 
 ``` c
 extern int c_add(int, int);
 #define C_TEN 10
 ```
 
-#### CSwift/CSwift/CSwift.c
+### C 函数体文件
+
+然后通过修改文件 `Sources/CSwift/CSwift.c`完成函数实现:
 
 ``` c
 #include "include/CSwift.h"
 int c_add(int a, int b) { return a + b ; }
 ```
 
-到此为止，C语言函数库就应该准备好了。
+### 模块映射
+
+下一步为Swift 语言构造一个映射模块文件：
+`Sources/CSwift/include/module.modulemap`
+
+``` swift
+module CSwift [system] {
+  header "CSwift.h"
+  export *
+}
+```
 
 ### Swift 程序调用
 
@@ -92,20 +80,17 @@ import XCTest
 @testable import CSwift
 
 class CSwiftTests: XCTestCase {
-    func testExample() {
-        // 测试调用 C 函数
-        let three = c_add(1, 2)
-        XCTAssertEqual(three, 3)
-        // 测试调用 C 语言的符号
-        XCTAssertEqual(C_TEN, 10)
-    }
-
-
-    static var allTests : [(String, (CSwiftTests) -> () throws -> Void)] {
-        return [
-            ("testExample", testExample),
-        ]
-    }
+  func testExample() {
+    // 测试调用 C 函数
+    let three = c_add(1, 2)
+    XCTAssertEqual(three, 3)
+    // 测试调用 C 语言的符号
+    XCTAssertEqual(C_TEN, 10)
+  }
+
+  static var allTests : [(String, (CSwiftTests) -> () throws -> Void)] {
+    return [ ("testExample", testExample)]
+  }
 }
 
 ```
@@ -128,6 +113,16 @@ $ swift test
 
 ### 动态链接库
 
+默认的Swift 4为静态编译，因此如果希望使用动态链接，则需要做一个调整。
+请打开Package.swift文件增加下一行：
+
+``` swift
+.library(
+    name: "CSwift",
+    type: .`dynamic`,  // <------------ 在这里增加新的一行
+    targets: ["CSwift"]),
+```
+
 本项目附带了一个特殊脚本dll.swift.script，内容为一个普通Swift 源程序：
 
 ``` swift

CSwift/include/module.modulemap → Sources/CSwift/include/module.modulemap

@@ -1,5 +1,4 @@
 module CSwift [system] {
   header "CSwift.h"
-  link "CSwift"
   export *
 }