Kotlin Multiplatform - Objective-C 互操作性架构问题架构 x86_64 的未定义符号

Question

我刚刚尝试使用本机互操作功能，因为我需要在我的库中使用用 Objective-C 编写的本机代码。 所以首先我尝试使用简单的 hello 来互操作 Objective-C 代码

毕业：

kotlin {
     ...
 
     val iosX64 = iosX64("ios") {
          compilations.getByName("main) {
              val myInterop by cinterops.creating {
                 defFile(project.file("src/nativeInterop/cinterop/objective-c-file.def"))
              }
          }
     }

     val iosArm32 = iosArm32 ("iosArm32 ") {
          compilations.getByName("main) {
              val myInterop by cinterops.creating {
                 defFile(project.file("src/nativeInterop/cinterop/objective-c-file.def"))
              }
          }
     }

     val iosArm64 = iosArm64("iosArm64") {
          compilations.getByName("main) {
              val myInterop by cinterops.creating {
                 defFile(project.file("src/nativeInterop/cinterop/objective-c-file.def"))
              }
          }
     }

     ...
}

我的 .def 配置：

language = Objective-C
headers = Hello.h Foundation/Foundation.h
package = org.native

compilerOpts = -Isrc/nativeInterop/include

linkerOpts = -framework Foundation "-F/Applications/Xcode 11.3.1.app/Contents/Developer/Platforms/"

这是项目结构的样子

我的你好.h

#import <Foundation/Foundation.h>

@interface Hello: NSObject

+ (id) init;
- (void) helloObjectiveC;

@end

你好.m

#import "Hello.h"

@implementation Hello

+ (id) init {}
- (void) helloObjectiveC {
    printf("hello Objective c interop")
}

@end

从 gradle 运行 cinterop 任务后，从那个 hello 类生成的 klib，当然现在我可以将它导入到我的 kotlin 项目中。例如在我的 iOS 模块中：

package bca.lib

import org.native.Hello

actual object Platform {

    actual fun getPlatform() = "iOSMain"
    
    fun helloNativeInterop() {
        val hello = Hello()
        hello.helloObjectiveC()
    }

}

然后我尝试在我的单元测试中调用它以检查我是否可以获得结果，或者我也尝试将它构建到框架但我得到一个错误：

> Task :cleanIosTest UP-TO-DATE
> Task :cinteropMyInteropIos UP-TO-DATE
> Task :generateBuildKonfig UP-TO-DATE
> Task :generateIosMainAppDatabaseInterface UP-TO-DATE
> Task :compileKotlinIos UP-TO-DATE
> Task :iosProcessResources UP-TO-DATE
> Task :iosMainKlibrary UP-TO-DATE
> Task :compileTestKotlinIos UP-TO-DATE
> Task :linkDebugTestIos FAILED
e: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld invocation reported errors
Please try to disable compiler caches and rerun the build. To disable compiler caches, add the following line to the gradle.properties file in the project's root directory:
    
    kotlin.native.cacheKind=none
    
Also, consider filing an issue with full Gradle log here: https://kotl.in/issue
The /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld command returned non-zero exit code: 1.
output:
Undefined symbols for architecture x86_64:
  "_OBJC_CLASS_$_Hello", referenced from:
      objc-class-ref in result.o
ld: symbol(s) not found for architecture x86_64
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':linkDebugTestIos'.
> Compilation finished with errors
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/6.6.1/userguide/command_line_interface.html#sec:command_line_warnings
BUILD FAILED in 8s

任何人都知道如何解决这个问题，或者也许不可能以这种方式进行互操作？我只是需要它，以便在我成功将其构建到 .framework 后稍后在我的 iOS 应用程序中使用它

Answer 1

这是一个已知限制，前段时间在 Kotlin 问题跟踪器中进行了描述：KT-39562。长话短说，cinterop 工具不提供开箱即用的源文件选项。这里最简单的方法是从您的 Objective-C 代码创建一个框架。之后，您将能够以文档中所述的简单方式使用它。