Hi guys, I’m a total newbie on kotlin native/multi...

# kotlin-native

[nayanjyoti]

Hi guys, I’m a total newbie on kotlin native/multiplatform projects. I tried to create a multi-platform project in idea community edition using the new project template.
it created a build.gradle file like this.

plugins {
    id 'kotlin-multiplatform' version '1.3.0-rc-146'
}

repositories {
    maven { url '<http://dl.bintray.com/kotlin/kotlin-eap>' }
    mavenCentral()
}
group 'com.example.sample'
version '0.0.1'

apply plugin: 'maven-publish'

kotlin {
    targets {
        fromPreset(presets.jvm, 'jvm')
        fromPreset(presets.js, 'js')
        // For ARM, preset should be changed to presets.iosArm32 or presets.iosArm64
        // For Linux, preset should be changed to e.g. presets.linuxX64
        // For MacOS, preset should be changed to e.g. presets.macosX64
        fromPreset(presets.macosX64, 'macos')
    }
    sourceSets {
        commonMain {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-stdlib-common'
            }
        }
        commonTest {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-test-common'
                implementation 'org.jetbrains.kotlin:kotlin-test-annotations-common'
            }
        }
        jvmMain {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8'
            }
        }
        jvmTest {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-test'
                implementation 'org.jetbrains.kotlin:kotlin-test-junit'
            }
        }
        jsMain {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-stdlib-js'
            }
        }
        jsTest {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-test-js'
            }
        }
        macosMain {
            dependencies {
            }
        }
        macosTest {
        }
    }
}

in the macos main module i want to include the ncurses library.
So I changed the part as

macosMain {
            dependencies {
             cinterop('ncurses') {
                    // something more
                }
            }
        }

I am getting error Could not find method cinterop() for arguments [ncurses, build_1mx5jx84o9toi8bpdxyehixos$_run_closure2$_closure6$_closure13$_closure21$_closure22@836eb38] on object of type org.jetbrains.kotlin.gradle.plugin.mpp.DefaultKotlinDependencyHandler.

Also I’m a total newbie to c/cpp or native world, so i may be doing something really stupid. if anyone can help i would b really grateful.

[orangy]

It should look something like this:

fromPreset(presets.macosX64, 'sdl2macos') {
                compilations.main {
                    cinterops {
                        sdl {
                            defFile = file("sdl2/interop/sdl2.def")
                        }
                    }
                }
            }

[nayanjyoti]

thanks @orangy. this worked. gradle build is working.
the def file i have is

headers = /usr/local/opt/ncurses/include/ncurses.h
headerFilter = /usr/local/opt/ncurses/include/ncursesw/*
linkerOpts.osx = -L/usr/local/opt/ncurses/lib -lncurses

The paths are all okay. the file /usr/local/opt/ncurses/include/ncurses.h is the header file from the installation of homebrew on mac mojave.
I used the command cinterop -def src/macosMain/ncurses.def -compilerOpts -I/usr/local/opt/ncurses/include -o src/macosMain/lib/ncurses to generate the binding to look into the functions.
On executing, a kotlin file is created at the path src/macosMain/lib/ncurses-build/kotlin/ncurses/ncurses.kt. The content od the file is empty. (apart from the package import and @file statements).content is below

@file:kotlinx.cinterop.InteropStubs
@file:Suppress("UNUSED_VARIABLE", "UNUSED_EXPRESSION")
package ncurses

import kotlin.native.SymbolName
import kotlinx.cinterop.*

// NOTE THIS FILE IS AUTO-GENERATED

This doesn’t seem right. I’m not even sure if I’m doing the right thing here. 😞

[orangy]

You don’t need to run cinterop manually, gradle task should handle it for you. Please check https://github.com/JetBrains/kotlin-native/blob/master/INTEROP.md for more information about .def files

[orangy]

Also it’s better to ask Kotlin/Native related questions in #kotlin-native channel

[nayanjyoti]

@orangy: Yes, I understand that. I was trying the cinterop when I hadn’t seen ur reply. However the generated file was empty like above. On running the gradle build, the generated kotlin file is empty, which doesn’t seem right. Can u suggest what I might be doing wrong?
We r in the #kotlin-native channel only. 🙈

[nayanjyoti]

This is the cinterop section in build.gradle

fromPreset(presets.macosX64, 'macos') {
            compilations.main {
                cinterops {
                    ncurses {
                        defFile = file('src/macosMain/ncurses.def')
                        includeDirs '/usr/local/opt/ncurses/include'
                    }
                }
            }
        }