1 files changed, 68 insertions, 0 deletions
diff --git a/plugin/src/main/scala/ch/jodersky/sbt/jni/plugins/JniJavah.scala b/plugin/src/main/scala/ch/jodersky/sbt/jni/plugins/JniJavah.scala
new file mode 100644
index 0000000..edda1fc
--- /dev/null
+++ b/plugin/src/main/scala/ch/jodersky/sbt/jni/plugins/JniJavah.scala
@@ -0,0 +1,68 @@
+package ch.jodersky.sbt.jni
+package plugins
+
+import sbt._
+import sbt.Keys._
+import util.BytecodeUtil
+
+/** Adds `javah` header-generation functionality to projects. */
+object JniJavah extends AutoPlugin {
+
+  override def requires = plugins.JvmPlugin
+  override def trigger = allRequirements
+
+  object autoImport {
+
+    val javahClasses = taskKey[Set[String]](
+      "Finds fully qualified names of classes containing native declarations."
+    )
+
+    val javah = taskKey[File](
+      "Generate JNI headers. Returns the directory containing generated headers."
+    )
+
+  }
+  import autoImport._
+
+  lazy val mainSettings: Seq[Setting[_]] = Seq(
+
+    javahClasses in javah := {
+      val compiled: inc.Analysis = (compile in Compile).value
+      val classFiles: Set[File] = compiled.relations.allProducts.toSet
+      val nativeClasses = classFiles flatMap { file =>
+        BytecodeUtil.nativeClasses(file)
+      }
+      nativeClasses
+    },
+
+    target in javah := target.value / "native" / "include",
+
+    javah := {
+      val out = (target in javah).value
+      val jcp: Seq[File] = { (compile in Compile).value; Seq((classDirectory in Compile).value) }
+      val cp = jcp.mkString(sys.props("path.separator"))
+      val log = streams.value.log
+
+      val classes = (javahClasses in javah).value
+      if (!classes.isEmpty) {
+        log.info("Headers will be generated to " + out.getAbsolutePath)
+      }
+      for (clazz <- classes) {
+        log.info("Generating header for " + clazz)
+        val parts = Seq(
+          "javah",
+          "-d", out.getAbsolutePath,
+          "-classpath", cp,
+          clazz
+        )
+        val cmd = parts.mkString(" ")
+        val ev = Process(cmd) ! streams.value.log
+        if (ev != 0) sys.error(s"Error occured running javah. Exit code: ${ev}")
+      }
+      out
+    }
+  )
+
+  override lazy val projectSettings = mainSettings
+
+}