Add support for downloading released executables from GitHub

Author: jonas

build.sbt

@@ -145,13 +145,22 @@ lazy val tools = project("tools")
 
 lazy val sbtPlugin = project("sbt-scala-native-bindgen", ScriptedPlugin)
   .dependsOn(tools)
+  .enablePlugins(BuildInfoPlugin)
   .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"
     },
+    buildInfoPackage := "org.scalanative.bindgen.sbt",
+    buildInfoKeys := Seq[BuildInfoKey](
+      version,
+      organization,
+      BuildInfoKey.map(scmInfo) {
+        case (k, v) => "projectUrl" -> v.get.browseUrl
+      }
+    ),
     publishLocal := publishLocal.dependsOn(tools / publishLocal).value
   )
 

project/plugins.sbt

@@ -5,5 +5,6 @@ addSbtPlugin("com.typesafe.sbt"  % "sbt-ghpages"                % "0.6.2")
 addSbtPlugin("com.typesafe.sbt"  % "sbt-git"                    % "1.0.0")
 addSbtPlugin("com.github.gseitz" % "sbt-release"                % "1.0.9")
 addSbtPlugin("org.foundweekends" % "sbt-bintray"                % "0.5.4")
+addSbtPlugin("com.eed3si9n"      % "sbt-buildinfo"              % "0.9.0")
 
 libraryDependencies += "org.scala-sbt" %% "scripted-plugin" % sbtVersion.value

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

@@ -3,6 +3,9 @@ package org.scalanative.bindgen.sbt
 import sbt._
 import sbt.Keys._
 
+import java.nio.file.Files
+import java.nio.file.attribute.{PosixFileAttributeView, PosixFilePermission}
+
 import org.scalanative.bindgen.Bindgen
 
 /**
@@ -42,8 +45,9 @@ import org.scalanative.bindgen.Bindgen
 object ScalaNativeBindgenPlugin extends AutoPlugin {
 
   object autoImport {
+    val ScalaNativeBindgen = config("scala-native-bindgen").hide
     val nativeBindgenPath =
-      taskKey[Option[File]]("Path to the scala-native-bindgen executable")
+      taskKey[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")
@@ -57,7 +61,46 @@ object ScalaNativeBindgenPlugin extends AutoPlugin {
   override def requires = plugins.JvmPlugin
 
   override def projectSettings: Seq[Setting[_]] =
-    nativeBindgenScopedSettings(Compile)
+    inConfig(ScalaNativeBindgen)(Defaults.configSettings) ++
+    nativeBindgenScopedSettings(Compile) ++
+    Def.settings(
+      ivyConfigurations += ScalaNativeBindgen,
+      version in nativeBindgen := BuildInfo.version,
+      libraryDependencies ++= {
+        artifactName.map { name =>
+          val bindgenVersion = (version in nativeBindgen).value
+          val url =
+            s"${BuildInfo.projectUrl}/releases/download/v$bindgenVersion/$name"
+
+          BuildInfo.organization % name % bindgenVersion % ScalaNativeBindgen from (url)
+        }.toSeq
+      },
+      nativeBindgenPath := {
+        val scalaNativeBindgenUpdate = (update in ScalaNativeBindgen).value
+
+        val artifactFile = artifactName match {
+          case None =>
+            sys.error(
+              "No downloadable binaries available for your OS, " +
+                "please provide path via `nativeBindgenPath`")
+          case Some(name) =>
+            scalaNativeBindgenUpdate
+              .select(artifact = artifactFilter(name = name))
+              .head
+        }
+
+        // Set the executable bit on the expected path to fail if it doesn't exist
+        for (view <- Option(
+                Files.getFileAttributeView(artifactFile.toPath,
+                                          classOf[PosixFileAttributeView]))) {
+          val permissions = view.readAttributes.permissions
+          if (permissions.add(PosixFilePermission.OWNER_EXECUTE))
+            view.setPermissions(permissions)
+        }
+
+        artifactFile
+      }
+    )
 
   private implicit class BindgenOps(val bindgen: Bindgen) extends AnyVal {
     def maybe[T](opt: Option[T], f: Bindgen => T => Bindgen): Bindgen =
@@ -67,23 +110,28 @@ object ScalaNativeBindgenPlugin extends AutoPlugin {
       }
   }
 
+  private val artifactName =
+    Option(System.getProperty("os.name")).collect {
+      case "Mac OS X" => "scala-native-bindgen-darwin"
+      case "Linux"    => "scala-native-bindgen-linux"
+    }
+
   def nativeBindgenScopedSettings(conf: Configuration): Seq[Setting[_]] =
     inConfig(conf)(
-      Seq(
+      Def.settings(
         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"
+          val output = sourceManaged.value / "sbt-scala-native-bindgen" / "ScalaNativeBindgen.scala"
 
           Bindgen()
-            .bindgenExecutable(nativeBindgenPath.value.get)
+            .bindgenExecutable(nativeBindgenPath.value)
             .header(nativeBindgenHeader.value)
             .name((name in nativeBindgen).value)
             .maybe(nativeBindgenLink.value, _.link)

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

@@ -5,7 +5,7 @@ scalaVersion := "2.11.12"
 
 inConfig(Compile)(
   Def.settings(
-    nativeBindgenPath := Option(System.getProperty("bindgen.path")).map(file),
+    nativeBindgenPath := file(System.getProperty("bindgen.path")),
     nativeBindgenHeader := (resourceDirectory in Compile).value / "header.h",
     nativeBindgenPackage := Some("org.example.app"),
     nativeBindgenLink := Some("app"),