How to add Kotlin files to CMake Build system

Usage
1

Currently, in our project we are suing java files for Android development. But we want to move to Kotlin files. Kotlin is similar to java only. And thus we though add_jar would be able to work fine with kotlin (.kt) files. But it failed with below error

ninja: error: FindFirstFileExA(CMakeFiles/TallyWorldMain_JAR.dir/D:/TW/Workspace/TallyWorld/FoundationalPlatform/TallyWorldMain.Source/TWMainAndroidKernel): The filename, directory name, or volume label syntax is incorrect.

I have .kit files under D:/TW/Workspace/TallyWorld/FoundationalPlatform/TallyWorldMain.Source/TWMainAndroidKernel folder.

Please let me know how to add kt files in our cmake build system. We are using Ninja Multi-Config generator.

Regards, Mohsin Siddiqui

2

Can you post the CMake code for this? Ideally, a self-contained example of what you are trying to do.

3

Hi @bill.hoffman

Please find the attachment for sample project. It has below three sample source files.

  1. SampleCpp.cpp ( to generate static library)
  2. SampleKotlin.kt
  3. SampleJava.kt
    Workspace.zip (2.3 MB)

If I generate jar using ajj_jar, it wroks fine, but when when I add .kt also in jar source file list, it gives me below error

D:\TW\Workspace>cmake --build --preset=Android_Phone-x64-Debug --target TWDevSupport
ninja: error: FindFirstFileExA(CMakeFiles/Test_Jar.dir/D:/TW/Workspace/TallyWorld/DevSupportPlatform/TWDevSupport.Source): The filename, directory name, or volume label syntax is incorrect.

4

So, the source for add_jar is here: CMake/UseJava.cmake at master · Kitware/CMake · GitHub. I assume .kt files need to be compiled with something other than the normal java compiler? Or is it that the same javac can be used for .kt and .java files. I guess add_jar needs to learn how to handle .kt files and treat them like .java files. You could try to edit this line: CMake/UseJava.cmake at master · Kitware/CMake · GitHub. to include .kt and java. That will only work if the javac can compile both .kt and .java.

5

Well… kotlin uses kotlin compiler to compile .kt files.

6

Then you would need to modify UseJava to recognize .kt files and use the kotlin compiler instead of javac to compile them. And put the result into the jar.

7

Yup. Thats exactly what we are doing.

8

Feel free to contribute this to CMake.

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