Swift Package 技巧及混编兼容问题详解

mkdir somePath
cd somePath
swift package init (--type library/executable/empty/system module)

// swift-tools-version:5.5
// The swift-tools-version declares the minimum version of Swift required to build this package.
import PackageDescription
let package = Package(
    name: "some name",
    products: [
        // Products define the executables and libraries a package produces, and make them visible to other packages.
        .library(
            name: "some name",
            targets: ["some name"]),
    ],
    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 this package depends on.
        .target(
            name: "some name",
            dependencies: []),
        .testTarget(
            name: "some name",
            dependencies: ["some name"]),
    ]
)

let package = Package(
    name: "MyModule",
    platforms: [.iOS(.v11),
                .macOS(.v11)],
    products: [
        // Products define the executables and libraries a package produces, and make them visible to other packages.
        .library(
            name: "MyModule",
            targets: ["MyModule", "MyModule_Objc"])
    ],
    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 this package depends on.
        .target(
            name: "MyModule_Objc",
            dependencies: [],
            publicHeadersPath: "include",
            cSettings: [.headerSearchPath(".")],
            cxxSettings: [.headerSearchPath(".")]
        ),
        .target(
            name: "MyModule",
            dependencies: ["MyModule_Objc"],
            path: "Sources/MyModule",
            swiftSettings: [.define("SPM_MODE")]
        ),
        .testTarget(
            name: "MyModuleTests",
            dependencies: ["MyModule"]),
    ]
)

- MyModule
  |
  |-README.md
  |
  |-Package.swift
  |
  |-Sources
    |
    |-MyModule
    | |
    | |- MyPackage.swift  
    |
    |-MyModule_Objc
      |
      |-Include
      | |
      | |- MyObjCClass.h
      |
      |- MyObjCClass.m

swiftSettings: [.define("SPM_MODE")]

import MyModule_Objc
// your code...

#if SPM_MODE
import FoundationX_Objc
#endif