[gradle-plugin] Support custom entry points (#1996)

GRADLE_PLUGIN.md

@@ -914,6 +914,9 @@ components.main {
 
     // Set up output kinds
     outputKinds = [EXECUTABLE, KLIBRARY, FRAMEWORK, DYNAMIC, STATIC]
+    
+    // Specify custom entry point for executables
+    entryPoint = "org.test.myMain"
 
     // Target-specific options
     target('linux_x64') {

tools/kotlin-native-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/experimental/KotlinNativeComponent.kt

@@ -106,6 +106,10 @@ interface KotlinNativeComponent: ComponentWithBinaries, ComponentWithDependencie
 
     val publishJavadoc: Boolean
     val publishSources: Boolean
+
+    /** Allows setting custom entry point for executables */
+    var entryPoint: String?
+    fun entryPoint(value: String)
     // endregion
 }
 

tools/kotlin-native-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/experimental/internal/AbstractKotlinNativeComponent.kt

@@ -155,5 +155,8 @@ abstract class AbstractKotlinNativeComponent @Inject constructor(
         action.execute(dependencies)
     }
 
+    override var entryPoint: String? = null
+    override fun entryPoint(value: String) { entryPoint = value }
+
     // endregion
 }

tools/kotlin-native-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/experimental/tasks/KotlinNativeCompile.kt

@@ -23,6 +23,7 @@ import org.gradle.api.file.FileSystemLocation
 import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.Input
 import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.Optional
 import org.gradle.api.tasks.TaskAction
 import org.jetbrains.kotlin.gradle.plugin.*
 import org.jetbrains.kotlin.gradle.plugin.experimental.internal.AbstractKotlinNativeBinary
@@ -59,6 +60,9 @@ open class KotlinNativeCompile @Inject constructor(internal val binary: Abstract
     val linkerOpts: List<String>
         @Input get() = binary.linkerOpts
 
+    val entryPoint: String?
+        @Optional @Input get() = binary.component.entryPoint
+
     val outputFile: File
         get() = outputLocationProvider.get().asFile
 
@@ -113,6 +117,8 @@ open class KotlinNativeCompile @Inject constructor(internal val binary: Abstract
 
             add("-Xmulti-platform")
 
+            addArgIfNotNull("-entry", entryPoint)
+
             addAll(additionalCompilerOptions)
 
             libraries.files.forEach {library ->

tools/kotlin-native-gradle-plugin/src/test/kotlin/ExperimentalPluginTests.kt

@@ -730,6 +730,39 @@ class ExperimentalPluginTests {
         }
     }
 
+    @Test
+    fun `Plugin should support custom entry points`() {
+        val hostSuffix = CompilerOutputKind.PROGRAM.suffix(HostManager.host)
+        val exePath = "build/exe/main/release/entry-point$hostSuffix"
+        val project = KonanProject.createEmpty(projectDirectory).apply {
+            buildFile.writeText("""
+                plugins { id 'kotlin-native' }
+
+                components.main {
+                    outputKinds = [EXECUTABLE]
+                    entryPoint = 'org.test.myMain'
+                }
+
+                task run(type: Exec) {
+                    commandLine file('$exePath').absolutePath
+                }
+            """.trimIndent())
+            settingsFile.appendText("rootProject.name = 'entry-point'")
+
+            generateSrcFile("main.kt", """
+                package org.test
+
+                fun myMain(args: Array<String>) {
+                    println("myMain called!")
+                }
+            """.trimIndent())
+        }
+        project.createRunner().withArguments(":assemble").build()
+        assertFileExists(exePath)
+        val result = project.createRunner().withArguments(":run").build()
+        assertTrue(result.output.contains("myMain called!"))
+    }
+
     @Test
     fun `Plugin should support the konan tooling model`() {
         withProject {
@@ -793,7 +826,7 @@ class ExperimentalPluginTests {
                         val outputRoot = if (kind == OutputKind.EXECUTABLE) "exe" else "lib"
                         val outputFile = file(
                             "build/$outputRoot/main/$buildType/${kind.name.toLowerCase()}/${target.name}/" +
-                            "testProject${kind.compilerOutputKind.suffix(target)}"
+                                    "testProject${kind.compilerOutputKind.suffix(target)}"
                         )
                         assertEquals(outputFile, artifact.file)
                     }