gradle-plugin: Support headerFilterAdditionalSearchPrefix

Support the headerFilterAdditionalSearchPrefix interop tool option
in the Gradle plugin

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

@@ -58,4 +58,14 @@ open class KonanInteropLibrary(name: String, project: ProjectInternal, instantia
 
     override fun link(vararg files: Any) = forEach { it.link(*files) }
     override fun link(files: FileCollection) = forEach { it.link(files) }
+
+    override fun headerFilterAdditionalSearchPrefix(path: Any) =
+            forEach { it.headerFilterAdditionalSearchPrefix(path) }
+
+    override fun headerFilterAdditionalSearchPrefixes(vararg paths: Any) =
+            headerFilterAdditionalSearchPrefixes(paths.toList())
+
+    override fun headerFilterAdditionalSearchPrefixes(paths: Collection<Any>) =
+            forEach { it.headerFilterAdditionalSearchPrefix(paths) }
+
 }

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

@@ -86,4 +86,8 @@ interface KonanInteropSpec: KonanBuildingSpec {
 
     fun link(vararg files: Any)
     fun link(files: FileCollection)
+
+    fun headerFilterAdditionalSearchPrefix(path: Any)
+    fun headerFilterAdditionalSearchPrefixes(vararg paths: Any)
+    fun headerFilterAdditionalSearchPrefixes(paths: Collection<Any>)
 }

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

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.gradle.plugin.tasks
 
+import org.gradle.api.InvalidUserDataException
 import org.gradle.api.file.FileCollection
 import org.gradle.api.tasks.*
 import org.jetbrains.kotlin.gradle.plugin.*
@@ -51,6 +52,8 @@ open class KonanInteropTask: KonanBuildingTask(), KonanInteropSpec {
     @InputFiles val headers   = mutableSetOf<FileCollection>()
     @InputFiles val linkFiles = mutableSetOf<FileCollection>()
 
+    @Input val headerFilterAdditionalSearchDirectories = mutableSetOf<File>()
+
     override fun buildArgs() = mutableListOf<String>().apply {
         addArg("-properties", "${project.konanHome}/konan/konan.properties")
 
@@ -82,6 +85,15 @@ open class KonanInteropTask: KonanBuildingTask(), KonanInteropSpec {
 
         addKey("-nodefaultlibs", noDefaultLibs)
 
+        addArgs("-headerFilterAdditionalSearchPrefix",
+                headerFilterAdditionalSearchDirectories.map {
+                    if (!it.isDirectory) {
+                        throw InvalidUserDataException("headerFilterAdditionalSearchPrefix must be a directory: $it")
+                    }
+                    it.absolutePath
+                }
+        )
+
         addAll(extraOpts)
     }
 
@@ -122,7 +134,18 @@ open class KonanInteropTask: KonanBuildingTask(), KonanInteropSpec {
     override fun link(files: FileCollection) {
         linkFiles.add(files)
     }
-    
+
+    override fun headerFilterAdditionalSearchPrefix(path: Any) {
+        headerFilterAdditionalSearchDirectories.add(project.file(path))
+    }
+
+    override fun headerFilterAdditionalSearchPrefixes(vararg paths: Any) =
+            headerFilterAdditionalSearchPrefixes(paths.toList())
+
+    override fun headerFilterAdditionalSearchPrefixes(paths: Collection<Any>) = paths.forEach {
+        headerFilterAdditionalSearchPrefix(it)
+    }
+
     // endregion
 }
 

tools/kotlin-native-gradle-plugin/src/test/groovy/org/jetbrains/kotlin/gradle/plugin/test/IncrementalSpecification.groovy

@@ -97,7 +97,7 @@ class IncrementalSpecification extends BaseKonanSpecification {
         "noDefaultLibs"       | "true"
     }
 
-    def 'Plugin should support custom entry points and recompile an artifact if it changes'() {
+    def 'Plugin should support a custom entry point and recompile an artifact if it changes'() {
         when:
         def project = KonanProject.createEmpty(projectDirectory) { KonanProject it ->
             it.addCompilerArtifact("main", """