Add initial scala-native-p script (#7)

* Add scala-native-p, a NIR deserialization program

It is based on the dumping feature of Scala Native, but slighly
redesigned to allow directly passing regular files and printing to
stdout instead of saving to a file. Because of that, it requires the
Scala Native utils dependency.

It features --help, --version and --classpath options. The last one allows to
pass a classpath where the NIR files are meant to be found. If not
passed, the files are looked for in cwd.

* Update sbt build to use a default main class

* Set main class in assembly

* Use NIR classloader to read contents of the files

* Add bash/batch scripts

* Adjust standalone scripts to allow testing scala-native-p

* Add mising blacnk lines in scripts

* Run scalafmt

Co-authored-by: Jan Chyb <jan.chyb.99@gmail.com>

Author: WojciechMazur

build.sbt

@@ -22,6 +22,8 @@ lazy val cli = project
   .enablePlugins(BuildInfoPlugin, ScriptedPlugin)
   .settings(
     name := "scala-native-cli",
+    Compile / run / mainClass :=
+      Some("scala.scalanative.cli.ScalaNativeCli"),
     scalacOptions += "-Ywarn-unused:imports",
     libraryDependencies ++= Seq(
       "org.scala-native" %% "tools" % scalaNativeVersion.value,
@@ -35,6 +37,7 @@ lazy val cli = project
     buildInfoPackage := "scala.scalanative.cli.options",
     cliAssemblyJarName := s"${normalizedName.value}-assembly_${scalaBinaryVersion.value}-${scalaNativeVersion.value}.jar",
     assembly / assemblyJarName := cliAssemblyJarName.value,
+    assembly / mainClass := (Compile / run / mainClass).value,
     scriptedLaunchOpts ++= {
       val jarName = cliAssemblyJarName.value
       val cliPath = (Compile / crossTarget).value / jarName

cli/src/main/scala/scala/scalanative/cli/ScalaNativeP.scala

@@ -0,0 +1,63 @@
+package scala.scalanative.cli
+
+import caseapp.core.app.CaseApp
+import caseapp.core.RemainingArgs
+import java.nio.file.Paths
+import java.io.File
+import scala.scalanative.util.Scope
+import scala.scalanative.cli.options._
+import scala.scalanative.nir.Global
+import scala.scalanative.build.Config
+import scala.scalanative.linker.ClassLoader
+
+object ScalaNativeP extends CaseApp[POptions] {
+
+  def run(options: POptions, args: RemainingArgs): Unit = {
+    if (options.misc.version) {
+      println(BuildInfo.nativeVersion)
+      exit(0)
+    }
+
+    if (args.all.isEmpty) {
+      System.err.println("Required NIR file not specified.")
+      exit(1)
+    }
+
+    val (classpath, ignoredPaths) =
+      options.classpath
+        .flatMap(_.split(File.pathSeparator))
+        .map(Paths.get(_))
+        .partition(_.toFile().exists())
+    ignoredPaths.foreach { path =>
+      System.err.println(s"Ignoring non existing path: $path")
+    }
+
+    Scope { implicit scope =>
+      val classLoader =
+        ClassLoader.fromDisk {
+          Config.empty.withClassPath(classpath)
+        }
+
+      for {
+        fileName <- args.all
+      } {
+        classLoader.load(Global.Top(fileName)) match {
+          case Some(defns) =>
+            defns
+              .sortBy(_.name.mangle)
+              .foreach { d =>
+                println(d.show)
+                println()
+              }
+          case None => fail(s"Not found class/object with name `${fileName}`")
+        }
+      }
+    }
+  }
+
+  private def fail(msg: String): Nothing = {
+    Console.err.println(msg)
+    exit(1)
+  }
+
+}

cli/src/main/scala/scala/scalanative/cli/options/POptions.scala

@@ -0,0 +1,14 @@
+package scala.scalanative.cli.options
+
+import caseapp._
+
+@ProgName("scala-native-p")
+@ArgsName("Class names")
+case class POptions(
+    @HelpMessage("Specify where to find user class files")
+    @ExtraName("cp")
+    @ValueDescription("<path>")
+    classpath: List[String] = "." :: Nil,
+    @Recurse
+    misc: MiscOptions
+)

cli/src/sbt-test/integration/standalone/Main.scala

@@ -3,3 +3,11 @@ object Main {
     println("Hello world")
   }
 }
+
+class Foo {
+  def foo = Foo.foo
+}
+
+object Foo {
+  val foo = "bar"
+}

cli/src/sbt-test/integration/standalone/build.sbt

@@ -14,7 +14,7 @@ val runExec = inputKey[Unit](
 )
 
 runScript := {
-  val scriptName +: args = spaceDelimited("<arg>").parsed.toSeq
+  val scriptName +: rawArgs = spaceDelimited("<arg>").parsed.toSeq
   val cliPackDir = System.getProperty("scala-native-cli-pack")
   val isWindows = System
     .getProperty("os.name", "unknown")
@@ -48,6 +48,15 @@ runScript := {
   }(Set(scalaBinDir))
 
   val script = Paths.get(cliPackDir, "bin", scriptName).toString
+  val args = rawArgs.map {
+    case "@NATIVE_LIB@" =>
+      Paths
+        .get(cliPackDir, "lib")
+        .toFile()
+        .listFiles()
+        .mkString(File.pathSeparator)
+    case arg => arg
+  }
   val proc =
     if (isWindows)
       new ProcessBuilder(

cli/src/sbt-test/integration/standalone/test

@@ -1,5 +1,13 @@
 > runScript scala-native-c Main.scala
 $ exists Main$.nir
+$ exists Foo.nir
+$ exists Foo$.nir 
+
+> runScript scala-native-p Main$ Foo Foo$
+> runScript scala-native-p Main$ --cp . --classpath target --cp IgnoredNotExistingDir
+> runScript scala-native-p --cp @NATIVE_LIB@ java.lang.Runnable
+
+-> runScript scala-native-p not.existing.Class
 
 > runScript scala-native-ld --main Main . -o scala-native-out.exe -v -v
 $ exists scala-native-out.exe

cli/src/script/scala-native-ld.bat

@@ -12,4 +12,4 @@ set CLILIB=%BASE%\scala-native-cli-assembly_%SCALA_BIN_VER%-%SCALANATIVE_VER%.ja
 set PLUGIN=%BASE%\nscplugin_%SCALA_VER%-%SCALANATIVE_VER%.jar
 set NATIVELIB=%BASE%\nativelib%SUFFIX% %BASE%\clib%SUFFIX% %BASE%\posixlib%SUFFIX% %BASE%\windowslib%SUFFIX% %BASE%\auxlib%SUFFIX% %BASE%\javalib%SUFFIX% %BASE%\scalalib%SUFFIX%
 
-scala -classpath %CLILIB% scala.scalanative.cli.ScalaNativeCli  %* %NATIVELIB%
+scala -classpath %CLILIB% scala.scalanative.cli.ScalaNativeCli  %* %NATIVELIB%

cli/src/script/scala-native-p

@@ -0,0 +1,9 @@
+#! /bin/sh
+
+SCALA_BIN_VER="@SCALA_BIN_VER@"
+SCALANATIVE_VER="@SCALANATIVE_VER@"
+
+BASE="$(dirname $0)/.."
+CLILIB="$BASE/lib/scala-native-cli-assembly_$SCALA_BIN_VER-$SCALANATIVE_VER.jar"
+
+scala -classpath "$CLILIB" scala.scalanative.cli.ScalaNativeP "$@"

cli/src/script/scala-native-p.bat

@@ -0,0 +1,10 @@
+@ECHO OFF
+SetLocal 
+
+set SCALA_BIN_VER=@SCALA_BIN_VER@
+set SCALANATIVE_VER=@SCALANATIVE_VER@
+
+set BASE=%~dp0\..\lib
+set CLILIB=%BASE%\scala-native-cli-assembly_%SCALA_BIN_VER%-%SCALANATIVE_VER%.jar
+
+scala -classpath %CLILIB% scala.scalanative.cli.ScalaNativeP  %*