Add sbt plugin (#60)

build.sbt

@@ -1,12 +1,19 @@
-import scala.scalanative.sbtplugin.ScalaNativePluginInternal.nativeWorkdir
 import scala.sys.process._
-import java.nio.file.Path
+
+addCommandAlias("verify", "; ^test:compile ; ^test ; ^scripted ; docs/makeSite")
+
+val Versions = new {
+  val scala210 = "2.10.6"
+  val scala211 = "2.11.12"
+  val scala212 = "2.12.6"
+  val sbt013   = "0.13.17"
+  val sbt1     = "1.1.6"
+}
 
 inThisBuild(
   Def.settings(
     organization := "org.scalanative.bindgen",
     version := "0.2-SNAPSHOT",
-    scalaVersion := "2.11.12",
     scalacOptions ++= Seq(
       "-deprecation",
       "-unchecked",
@@ -20,10 +27,18 @@ inThisBuild(
     git.remoteRepo := scmInfo.value.get.connection.replace("scm:git:", "")
   ))
 
-val tests = project
-  .in(file("tests"))
+val root = project("scala-native-bindgen")
+  .in(file("."))
+  .aggregate(
+    tests,
+    samples,
+    tools,
+    sbtPlugin,
+    docs
+  )
+
+lazy val tests = project("tests")
   .dependsOn(tools)
-  .aggregate(samples)
   .settings(
     fork in Test := true,
     javaOptions in Test += {
@@ -38,10 +53,11 @@ val tests = project
     libraryDependencies += "org.scalatest" %% "scalatest" % "3.0.5" % Test
   )
 
-lazy val samples = project
+lazy val samples = project("samples")
   .in(file("tests/samples"))
   .enablePlugins(ScalaNativePlugin)
   .settings(
+    scalaVersion := Versions.scala211,
     libraryDependencies += "com.lihaoyi" %%% "utest" % "0.6.3" % "test",
     testFrameworks += new TestFramework("utest.runner.Framework"),
     nativeLinkStubs := true,
@@ -91,19 +107,45 @@ lazy val samples = project
     }
   )
 
-lazy val tools = project in file("tools")
+lazy val tools = project("tools")
+
+lazy val sbtPlugin = project("sbt-scala-native-bindgen", ScriptedPlugin)
+  .dependsOn(tools)
+  .settings(
+    Keys.sbtPlugin := true,
+    scriptedLaunchOpts += s"-Dplugin.version=${version.value}",
+    scriptedLaunchOpts += {
+      val rootDir = (ThisBuild / baseDirectory).value
+      s"-Dbindgen.path=$rootDir/bindgen/target/scala-native-bindgen"
+    },
+    publishLocal := publishLocal.dependsOn(tools / publishLocal).value
+  )
 
-lazy val docs = project
-  .in(file("docs"))
+lazy val docs = project("docs")
   .enablePlugins(GhpagesPlugin, ParadoxSitePlugin, ParadoxMaterialThemePlugin)
   .settings(
     paradoxProperties in Paradox ++= Map(
       "github.base_url" -> scmInfo.value.get.browseUrl.toString
     ),
     ParadoxMaterialThemePlugin.paradoxMaterialThemeSettings(Paradox),
-    paradoxMaterialTheme in Paradox := {
-      (paradoxMaterialTheme in Paradox).value
+    Paradox / paradoxMaterialTheme := {
+      (Paradox / paradoxMaterialTheme).value
         .withRepository(scmInfo.value.get.browseUrl.toURI)
         .withColor("indigo", "indigo")
     }
   )
+
+def project(name: String, plugged: AutoPlugin*) = {
+  val unplugged = Seq(ScriptedPlugin).filterNot(plugged.toSet)
+  Project(id = name, base = file(name))
+    .disablePlugins(unplugged: _*)
+    .settings(
+      crossSbtVersions := List(Versions.sbt013, Versions.sbt1),
+      scalaVersion := {
+        (pluginCrossBuild / sbtBinaryVersion).value match {
+          case "0.13" => Versions.scala210
+          case _      => Versions.scala212
+        }
+      }
+    )
+}

project/plugins.sbt

@@ -2,3 +2,5 @@ addSbtPlugin("org.scala-native" % "sbt-scala-native"           % "0.3.7")
 addSbtPlugin("com.typesafe.sbt" % "sbt-site"                   % "1.3.2")
 addSbtPlugin("io.github.jonas"  % "sbt-paradox-material-theme" % "0.4.0")
 addSbtPlugin("com.typesafe.sbt" % "sbt-ghpages"                % "0.6.2")
+
+libraryDependencies += "org.scala-sbt" %% "scripted-plugin" % sbtVersion.value

sbt-scala-native-bindgen/src/main/scala/org/scalanative/bindgen/sbt/ScalaNativeBindgenPlugin.scala

@@ -0,0 +1,98 @@
+package org.scalanative.bindgen.sbt
+
+import sbt._
+import sbt.Keys._
+
+import org.scalanative.bindgen.Bindgen
+
+/**
+ * Generate Scala bindings from C headers.
+ *
+ * == Usage ==
+ *
+ * This plugin must be explicitly enabled. To enable it add the following line
+ * to your `.sbt` file:
+ * {{{
+ * enablePlugins(ScalaNativeBindgenPlugin)
+ * }}}
+ *
+ * By default, the plugin reads the configured header file and generates
+ * a single Scala source file in the managed source directory.
+ *
+ * See the [[https://github.com/kornilova-l/scala-native-bindgen/tree/master/sbt-scala-native-bindgen/src/sbt-test/bindgen/generate example project]].
+ *
+ * == Configuration ==
+ *
+ * Keys are defined in [[ScalaNativeBindgenPlugin.autoImport]].
+ *
+ *  - `nativeBindgenHeader`: The C header file to read.
+ *
+ *  - `nativeBindgenPackage`: Package of the enclosing object.
+ *    No package by default.
+ *
+ *  - `name in nativeBindgen`: Name of the enclosing object.
+ *
+ * @example
+ * {{{
+ * nativeBindgenHeader in Compile := file("/usr/include/ctype.h")
+ * nativeBindgenPackage in Compile := Some("org.example.app")
+ * name in (Compile, nativeBindgen) := "ctype"
+ * }}}
+ */
+object ScalaNativeBindgenPlugin extends AutoPlugin {
+
+  object autoImport {
+    val nativeBindgenPath =
+      taskKey[Option[File]]("Path to the scala-native-bindgen executable")
+    val nativeBindgenHeader = taskKey[File]("C header file")
+    val nativeBindgenPackage =
+      settingKey[Option[String]]("Package for the generated code")
+    val nativeBindgenLink =
+      settingKey[Option[String]]("Name of library to be linked")
+    val nativeBindgenExclude = settingKey[Option[String]]("Exclude prefix")
+    val nativeBindgen        = taskKey[File]("Generate Scala Native bindings")
+  }
+  import autoImport._
+
+  override def requires = plugins.JvmPlugin
+
+  override def projectSettings: Seq[Setting[_]] =
+    nativeBindgenScopedSettings(Compile)
+
+  private implicit class BindgenOps(val bindgen: Bindgen) extends AnyVal {
+    def maybe[T](opt: Option[T], f: Bindgen => T => Bindgen): Bindgen =
+      opt match {
+        case None        => bindgen
+        case Some(value) => f(bindgen)(value)
+      }
+  }
+
+  def nativeBindgenScopedSettings(conf: Configuration): Seq[Setting[_]] =
+    inConfig(conf)(
+      Seq(
+        nativeBindgenHeader := {
+          sys.error("nativeBindgenHeader not configured")
+        },
+        nativeBindgenPath := None,
+        nativeBindgenPackage := None,
+        nativeBindgenExclude := None,
+        resourceDirectories in nativeBindgen := resourceDirectories.value,
+        sourceGenerators += Def.task { Seq(nativeBindgen.value) },
+        name in nativeBindgen := "ScalaNativeBindgen",
+        nativeBindgen := {
+          val output = sourceManaged.value / "sbt-scala-native-bindgen" / "nativeBindgen.scala"
+
+          Bindgen()
+            .bindgenExecutable(nativeBindgenPath.value.get)
+            .header(nativeBindgenHeader.value)
+            .name((name in nativeBindgen).value)
+            .maybe(nativeBindgenLink.value, _.link)
+            .maybe(nativeBindgenPackage.value, _.packageName)
+            .maybe(nativeBindgenExclude.value, _.excludePrefix)
+            .generate()
+            .writeToFile(output)
+
+          output
+        }
+      ))
+}

sbt-scala-native-bindgen/src/sbt-test/bindgen/generate/build.sbt

@@ -0,0 +1,35 @@
+name := "test"
+organization := "org.scalanative.bindgen.sbt.test"
+enablePlugins(ScalaNativeBindgenPlugin)
+scalaVersion := "2.11.12"
+
+inConfig(Compile)(
+  Def.settings(
+    nativeBindgenPath := Option(System.getProperty("bindgen.path")).map(file),
+    nativeBindgenHeader := (resourceDirectory in Compile).value / "header.h",
+    nativeBindgenPackage := Some("org.example.app"),
+    nativeBindgenLink := Some("app"),
+    nativeBindgenExclude := Some("__"),
+    name in nativeBindgen := "AppAPI"
+  ))
+
+TaskKey[Unit]("check") := {
+  val file = (nativeBindgen in Compile).value
+  val expected =
+    """package org.example.app
+      |
+      |import scala.scalanative._
+      |import scala.scalanative.native._
+      |
+      |@native.link("app")
+      |@native.extern
+      |object AppAPI {
+      |  def access(path: native.CString, mode: native.CInt): native.CInt = native.extern
+      |  def read(fildes: native.CInt, buf: native.Ptr[Byte], nbyte: native.CInt): native.CInt = native.extern
+      |  def printf(format: native.CString, varArgs: native.CVararg*): native.CInt = native.extern
+      |}
+    """.stripMargin
+
+  assert(file.exists)
+  assert(IO.read(file).trim == expected.trim)
+}

sbt-scala-native-bindgen/src/sbt-test/bindgen/generate/project/plugins.sbt

@@ -0,0 +1,3 @@
+addSbtPlugin(
+  "org.scalanative.bindgen" % "sbt-scala-native-bindgen" % sys.props(
+    "plugin.version"))

sbt-scala-native-bindgen/src/sbt-test/bindgen/generate/src/main/resources/header.h

@@ -0,0 +1,3 @@
+int access(const char *path, int mode);
+int read(int fildes, void *buf, int nbyte);
+int printf(const char *restrict format, ...);

sbt-scala-native-bindgen/src/sbt-test/bindgen/generate/test

@@ -0,0 +1 @@
+> check

scripts/test.sh

@@ -13,4 +13,4 @@ if [[ ! -e bindgen/target/.llvm-version ]] || [[ "$(<bindgen/target/.llvm-versio
 fi
 
 make -C bindgen/target
-sbt "${@:-test}"
+sbt "${@:-verify}"

tools/src/main/scala/org/scalanative/bindgen/Bindgen.scala

@@ -129,7 +129,7 @@ object Bindgen {
         withArgs("--extra-arg-before", extraArgBefore) ++
         Seq(header.get.getAbsolutePath, "--")
 
-      val output = Process(cmd).lineStream.mkString("\n")
+      val output = Process(cmd).!!
 
       new Bindings(output)
     }

tools/src/main/scala/org/scalanative/bindgen/Bindings.scala

@@ -4,6 +4,7 @@ import java.io.{File, PrintWriter}
 
 class Bindings(private val bindings: String) {
   def writeToFile(file: File): Unit = {
+    file.getParentFile.mkdirs()
     new PrintWriter(file) {
       write(bindings)
       close()