如何在CocoaPods中集成同架构（arm64）iOS与iOS模拟器静态库？

我们有一个通过spec.vendored_libraries引用静态库的podspec，该静态库已构建两个arm64架构版本：

• iOS设备版本（路径：iosArm64/lib/a.a）
• iOS模拟器版本（路径：iosSimulatorArm64/lib/a.a）

现有podspec代码如下：

Pod::Spec.new do |spec|
    spec.platform                 = :ios
    spec.name                     = 'pod_lib'
    spec.version                  = '1.0.0'
    spec.homepage                 = 'pod_lib'
    spec.source                   = { :git => "Not Published", :tag => "Cocoapods/#{spec.name}/#{spec.version}" }
    spec.authors                  = 'Authors'
    spec.license                  = ''
    spec.summary                  = 'pod_lib'
    spec.ios.deployment_target    = '13.5'
    spec.source_files             = 'headers/**/*.h'
    spec.public_header_files      = 'headers/**/*.h'
    spec.vendored_libraries       = 'iosArm64/lib/a.a'
    spec.header_mappings_dir      = 'headers'
    spec.static_framework         = true
    spec.libraries                = 'c++'
    spec.pod_target_xcconfig      = {
    'CLANG_CXX_LANGUAGE_STANDARD' => 'c++20',
    'CLANG_CXX_LIBRARY' => 'libc++',
    'ARCHS' => 'arm64',
    }
end

我们尝试在podspec中同时指定两个库：

spec.vendored_libraries       = 'iosArm64/lib/a.a',
                                'iosSimulatorArm64/lib/a.a'

但由于两个库文件名相同，且CocoaPods暂不支持该场景，此写法无法生效。另外尝试用lipo合并通用二进制：

lipo -create -output libuniversal.a ./iosArm64/lib/a.a ./iosSimulatorArm64/lib/a.a

但因为两者都是arm64架构，lipo无法完成合并。

请问能否通过一个CocoaPod同时兼容这两个平台的库？或者有其他可行的解决方案？

方案1：通过Podfile的pre_install钩子动态替换库路径 #

在项目的Podfile中添加钩子，根据当前构建的目标平台，替换podspec中的vendored_libraries路径：

pre_install do |installer|
  installer.pod_targets.each do |target|
    next unless target.name == 'pod_lib'
    if installer.podfile.target_definitions.values.first.platform.name == :ios && installer.podfile.target_definitions.values.first.platform.simulator?
      target.specification.attributes['vendored_libraries'] = ['iosSimulatorArm64/lib/a.a']
    else
      target.specification.attributes['vendored_libraries'] = ['iosArm64/lib/a.a']
    end
  end
end

这种方式需要使用该pod的项目配合修改Podfile，适合内部私有库场景。

方案2：拆分Subspec区分平台 #

在podspec中定义两个subspec，分别对应设备和模拟器版本，用户可以根据需要选择：

Pod::Spec.new do |spec|
    spec.platform                 = :ios
    spec.name                     = 'pod_lib'
    spec.version                  = '1.0.0'
    spec.homepage                 = 'pod_lib'
    spec.source                   = { :git => "Not Published", :tag => "Cocoapods/#{spec.name}/#{spec.version}" }
    spec.authors                  = 'Authors'
    spec.license                  = ''
    spec.summary                  = 'pod_lib'
    spec.ios.deployment_target    = '13.5'
    spec.source_files             = 'headers/**/*.h'
    spec.public_header_files      = 'headers/**/*.h'
    spec.header_mappings_dir      = 'headers'
    spec.static_framework         = true
    spec.libraries                = 'c++'
    spec.pod_target_xcconfig      = {
        'CLANG_CXX_LANGUAGE_STANDARD' => 'c++20',
        'CLANG_CXX_LIBRARY' => 'libc++',
        'ARCHS' => 'arm64',
    }

    spec.subspec 'Device' do |device|
      device.vendored_libraries = 'iosArm64/lib/a.a'
    end

    spec.subspec 'Simulator' do |sim|
      sim.vendored_libraries = 'iosSimulatorArm64/lib/a.a'
    end
end

用户在Podfile中可以根据平台选择依赖：

# 设备环境
pod 'pod_lib/Device', '1.0.0'
# 模拟器环境
pod 'pod_lib/Simulator', '1.0.0'

方案3：修改静态库文件名并通过XCConfig条件指定 #

将两个库重命名为不同的文件名（比如a_ios.a和a_sim.a），然后在podspec的pod_target_xcconfig中通过SDK条件配置，让不同平台自动链接对应库：

Pod::Spec.new do |spec|
    spec.platform                 = :ios
    spec.name                     = 'pod_lib'
    spec.version                  = '1.0.0'
    # 其他基础配置...
    spec.vendored_libraries = 'iosArm64/lib/a_ios.a', 'iosSimulatorArm64/lib/a_sim.a'
    spec.pod_target_xcconfig = {
        'CLANG_CXX_LANGUAGE_STANDARD' => 'c++20',
        'CLANG_CXX_LIBRARY' => 'libc++',
        'ARCHS' => 'arm64',
        'OTHER_LDFLAGS[sdk=iphoneos*]' => '-l"a_ios"',
        'OTHER_LDFLAGS[sdk=iphonesimulator*]' => '-l"a_sim"',
        'LIBRARY_SEARCH_PATHS[sdk=iphoneos*]' => '$(PODS_ROOT)/pod_lib/iosArm64/lib',
        'LIBRARY_SEARCH_PATHS[sdk=iphonesimulator*]' => '$(PODS_ROOT)/pod_lib/iosSimulatorArm64/lib'
    }
end

方案4：使用构建脚本动态替换库文件 #

在podspec中添加脚本阶段，在编译时根据当前平台复制对应的库到统一目录，再进行链接：

Pod::Spec.new do |spec|
    # 其他基础配置...
    spec.vendored_libraries = 'lib/a.a'
    spec.script_phases = [
      {
        :name => 'Select Correct Static Library',
        :script => <<-SCRIPT
          mkdir -p "${PODS_TARGET_SRCROOT}/lib"
          if [ "${SDK_NAME}" = "iphonesimulator" ]; then
            cp "${PODS_TARGET_SRCROOT}/iosSimulatorArm64/lib/a.a" "${PODS_TARGET_SRCROOT}/lib/a.a"
          else
            cp "${PODS_TARGET_SRCROOT}/iosArm64/lib/a.a" "${PODS_TARGET_SRCROOT}/lib/a.a"
          fi
        SCRIPT
      }
    ]
end

脚本会在每次构建时自动替换为对应平台的库文件，无需用户额外操作。

内容的提问来源于stack exchange，提问作者Felix