KrossCompilePlugin

Overview

The KrossCompilePlugin is a Gradle plugin designed to simplify the integration of CMake projects into Kotlin/Native projects. This is achieved by cross-compiling the CMake project for various targets and setting the Kotlin/Native's CInterop tool to link it as a static binary into a klib file.

Key Features

1. Cross-Compilation: The plugin supports cross-compiling CMake projects for multiple platforms including Android, Linux, Windows, and various Apple operating systems.
2. CInterop Integration: The plugin integrates with Kotlin/Native's CInterop tool to link the compiled CMake project as a static binary into a klib file.
3. Customizable Build Configurations: The plugin allows you to define different building configurations/flags for each target in the gradle script.

Prerequisites

• CMake installed on the system. Available here.
• Android NDK, XCode, Clang, Zig or any toolchain thing you'll need during the compilation progress.

Installation

Apply the plugin to your project:

plugins {
    id("io.github.isning.gradle.plugins.kn.krossCompile") version "0.1.9"
}

Usage

Here is an example of how to use the KrossCompilePlugin:

krossCompile {
    libraries {
        val zxingCpp by creating {
            // Define the source directory of the CMake project
            sourceDir = file("../zxing-cpp").absolutePath
            outputPath = ""

            // Setup CInterop
            cinterop {
                packageName = "zxing.cinterop"
                headers = listOf("zxing-c.h")
                includeDirs.from("$sourceDir/core/src")
            }

            // Define CMake configurations
            cmake.apply {
                val buildPath = project.layout.buildDirectory.dir("cmake").get().asFile.absolutePath +
                        "/{projectName}/{targetName}"
                outputPath = "core"
                libraryArtifactNames = listOf("libZXing.a")
                configParams {
                    buildDir = buildPath
                }
                configParams += ModifiablePlatformEntriesImpl().apply {
                    buildType = "Release"
                    buildSharedLibs = false
                }.asCMakeParams
                buildParams {
                    buildDir = buildPath
                    config = "Release"
                }
                // Multithreaded compilation
                buildParams += CustomCMakeParams(listOf("-j16"))
            }

            // Define target platforms
            androidNativeX64.konan()
            androidNativeX86.konan()
            androidNativeArm32.konan()
            androidNativeArm64.konan()

            linuxX64.konan()
            linuxArm64.konan()
            mingwX64.konan()

            if (hostOs == "Mac OS X") {
                iosX64.konan()
                iosArm64.konan()
                iosSimulatorArm64.konan()
                macosX64.konan()
                macosArm64.konan()
                watchosX64.konan()
                watchosArm32.konan()
                watchosArm64.konan()
                watchosSimulatorArm64.konan()
                tvosX64.konan()
                tvosArm64.konan()
                tvosSimulatorArm64.konan()
            }
        }
    }
}

Properties

• sourceDir: Defines the source directory of the CMake project.
• outputPath: Defines the output path of the compiled library.
• cinterop: Configures the CInterop tool (properties definition are aligned to K/N's cinterop configuration).
  • packageName: Specifies the package name for the generated bindings.
  • headers: Lists the header files to generate bindings for.
  • includeDirs: Specifies the directories to search for header files.
  • ... For more properties, you can read c interoperation part of K/N official document.

And for all the properties of cinterop, there are several stub strings that will be replaced by the plugin:

Stub String	To
{gradleProjectName}	The name of gradle project
{libraryName}	The name of the library
{targetName}	The name of the target

Note: The stub strings of cinterop properties and cmake properties are different, for cmake properties, refer to here.

• cmake: Configures the CMake build.
  • outputPath: Specifies the output binary's relative path of from the build directory.
  • libraryArtifactNames: Lists the names of the library artifacts to be produced by the CMake build. As well as static library's names.
  • configParams: Defines the configuration parameters for the CMake build.
  • buildParams: Defines the build parameters for the CMake build.
• androidNative[arch]/{konan,ndk,clang,zig}(): Configures the Android targets. Replace [arch] with the architecture (e.g., X64, X86, Arm32, Arm64) and choose the compiler (konan, ndk, clang, zig).
• linux[arch].{konan,clang, zig}(): Configures the Linux targets. Replace [arch] with the architecture (e.g., X64, Arm64) and choose the compiler (konan, clang, zig).
• [apple target][arch].{konan,xcode,clang,zig}(): Configures the Apple targets. Replace [apple target] with the target platform (e.g., ios, macos, watchos, tvos), [arch] with the architecture (e.g., X64, Arm64) and choose the compiler (konan, xcode, clang, zig).

Compiler preset konan is Highly recommended for it can keep building toolchain aligned with K/N compiling progress to avoid potential linking failure.

Note: To know more about configuring cmake block, see CMakePlugin

Support

For any issues or feature requests, please create an issue.

License

The KrossCompilePlugin is licensed under the Apache License, Version 2.0 with no warranty (expressed or implied) for any purpose.