Merge pull request #3685 from dotty-staging/implemet-quote-run

Implement Expr.{run|show}

Author: odersky

compiler/src/dotty/tools/dotc/CompilationUnit.scala

@@ -8,6 +8,7 @@ import dotty.tools.dotc.ast.tpd.{ Tree, TreeTraverser }
 import dotty.tools.dotc.core.Contexts.Context
 import dotty.tools.dotc.core.SymDenotations.ClassDenotation
 import dotty.tools.dotc.core.Symbols._
+import dotty.tools.dotc.transform.SymUtils._
 
 class CompilationUnit(val source: SourceFile) {
 
@@ -31,17 +32,29 @@ class CompilationUnit(val source: SourceFile) {
 object CompilationUnit {
 
   /** Make a compilation unit for top class `clsd` with the contends of the `unpickled` */
-  def mkCompilationUnit(clsd: ClassDenotation, unpickled: Tree, forceTrees: Boolean)(implicit ctx: Context): CompilationUnit = {
+  def mkCompilationUnit(clsd: ClassDenotation, unpickled: Tree, forceTrees: Boolean)(implicit ctx: Context): CompilationUnit =
+    mkCompilationUnit(new SourceFile(clsd.symbol.associatedFile, Seq()), unpickled, forceTrees)
+
+  /** Make a compilation unit the given unpickled tree */
+  def mkCompilationUnit(source: SourceFile, unpickled: Tree, forceTrees: Boolean)(implicit ctx: Context): CompilationUnit = {
     assert(!unpickled.isEmpty, unpickled)
-    val unit1 = new CompilationUnit(new SourceFile(clsd.symbol.associatedFile, Seq()))
+    val unit1 = new CompilationUnit(source)
     unit1.tpdTree = unpickled
-    if (forceTrees)
+    if (forceTrees) {
+      val force = new Force
       force.traverse(unit1.tpdTree)
+      unit1.containsQuotesOrSplices = force.containsQuotes
+    }
     unit1
   }
 
   /** Force the tree to be loaded */
-  private object force extends TreeTraverser {
-    def traverse(tree: Tree)(implicit ctx: Context): Unit = traverseChildren(tree)
+  private class Force extends TreeTraverser {
+    var containsQuotes = false
+    def traverse(tree: Tree)(implicit ctx: Context): Unit = {
+      if (tree.symbol.isQuote)
+        containsQuotes = true
+      traverseChildren(tree)
+    }
   }
 }

compiler/src/dotty/tools/dotc/quoted/ExprCompilationUnit.scala

@@ -0,0 +1,11 @@
+package dotty.tools.dotc.quoted
+
+import dotty.tools.dotc.CompilationUnit
+import dotty.tools.dotc.util.NoSource
+
+import scala.quoted.Expr
+
+/* Compilation unit containing the contents of a quoted expression */
+class ExprCompilationUnit(val expr: Expr[_]) extends CompilationUnit(NoSource) {
+  override def toString = s"Expr($expr)"
+}

compiler/src/dotty/tools/dotc/quoted/ExprCompiler.scala

@@ -0,0 +1,95 @@
+package dotty.tools.dotc
+package quoted
+
+import dotty.tools.backend.jvm.GenBCode
+import dotty.tools.dotc.ast.tpd
+
+import dotty.tools.dotc.core.Contexts.Context
+import dotty.tools.dotc.core.Flags.{EmptyFlags, Method}
+import dotty.tools.dotc.core.{Mode, Phases}
+import dotty.tools.dotc.core.Phases.Phase
+import dotty.tools.dotc.core.Scopes.{EmptyScope, newScope}
+import dotty.tools.dotc.core.StdNames.nme
+import dotty.tools.dotc.core.Symbols.defn
+import dotty.tools.dotc.core.Types.ExprType
+import dotty.tools.dotc.core.quoted.PickledQuotes
+import dotty.tools.dotc.transform.ReifyQuotes
+import dotty.tools.dotc.typer.FrontEnd
+import dotty.tools.dotc.util.Positions.Position
+import dotty.tools.dotc.util.SourceFile
+import dotty.tools.io.{Path, PlainFile, VirtualDirectory}
+
+import scala.quoted.Expr
+
+/** Compiler that takes the contents of a quoted expression `expr` and produces
+ *  a class file with `class ' { def apply: Object = expr }`.
+ */
+class ExprCompiler(directory: VirtualDirectory) extends Compiler {
+  import tpd._
+
+  /** A GenBCode phase that outputs to a virtual directory */
+  private class ExprGenBCode extends GenBCode {
+    override def phaseName = "genBCode"
+    override def outputDir(implicit ctx: Context) = directory
+  }
+
+  override protected def frontendPhases: List[List[Phase]] =
+    List(List(new ExprFrontend(putInClass = true)))
+
+  override protected def picklerPhases: List[List[Phase]] =
+    List(List(new ReifyQuotes))
+
+  override protected def backendPhases: List[List[Phase]] =
+    List(List(new ExprGenBCode))
+
+  override def newRun(implicit ctx: Context): ExprRun = {
+    reset()
+    new ExprRun(this, ctx.addMode(Mode.ReadPositions))
+  }
+
+  /** Frontend that receives scala.quoted.Expr as input */
+  class ExprFrontend(putInClass: Boolean) extends FrontEnd {
+    import tpd._
+
+    override def isTyper = false
+
+    override def runOn(units: List[CompilationUnit])(implicit ctx: Context): List[CompilationUnit] = {
+      units.map {
+        case exprUnit: ExprCompilationUnit =>
+          val tree =
+            if (putInClass) inClass(exprUnit.expr)
+            else PickledQuotes.quotedToTree(exprUnit.expr)
+          val source = new SourceFile("", Seq())
+          CompilationUnit.mkCompilationUnit(source, tree, forceTrees = true)
+      }
+    }
+
+    /** Places the contents of expr in a compilable tree for a class
+      *  with the following format.
+      *  `package __root__ { class ' { def apply: Any = <expr> } }`
+      */
+    private def inClass(expr: Expr[_])(implicit ctx: Context): Tree = {
+      val pos = Position(0)
+      val assocFile = new PlainFile(Path("<quote>"))
+
+      val cls = ctx.newCompleteClassSymbol(defn.RootClass, nme.QUOTE.toTypeName, EmptyFlags,
+        defn.ObjectType :: Nil, newScope, coord = pos, assocFile = assocFile).entered.asClass
+      cls.enter(ctx.newDefaultConstructor(cls), EmptyScope)
+      val meth = ctx.newSymbol(cls, nme.apply, Method, ExprType(defn.AnyType), coord = pos).entered
+
+      val quoted = PickledQuotes.quotedToTree(expr)(ctx.withOwner(meth))
+
+      val run = DefDef(meth, quoted)
+      val classTree = ClassDef(cls, DefDef(cls.primaryConstructor.asTerm), run :: Nil)
+      PackageDef(ref(defn.RootPackage).asInstanceOf[Ident], classTree :: Nil).withPos(pos)
+    }
+  }
+
+  class ExprRun(comp: Compiler, ictx: Context) extends Run(comp, ictx) {
+    def compileExpr(expr: Expr[_]): Unit = {
+      val units = new ExprCompilationUnit(expr) :: Nil
+      compileUnits(units)
+    }
+  }
+
+}

compiler/src/dotty/tools/dotc/quoted/ExprDecompiler.scala

@@ -0,0 +1,15 @@
+package dotty.tools.dotc.quoted
+
+import java.io.PrintStream
+
+import dotty.tools.dotc.core.Phases.Phase
+
+/** Compiler that takes the contents of a quoted expression `expr` and produces outputs
+ *  the pretty printed code.
+ */
+class ExprDecompiler(out: PrintStream) extends ExprCompiler(null) {
+  override def phases: List[List[Phase]] = List(
+    List(new ExprFrontend(putInClass = false)), // Create class from Expr
+    List(new QuotePrinter(out)) // Print all loaded classes
+  )
+}

compiler/src/dotty/tools/dotc/quoted/QuoteDriver.scala

@@ -0,0 +1,56 @@
+package dotty.tools.dotc.quoted
+
+import dotty.tools.dotc.Driver
+import dotty.tools.dotc.core.Contexts.{Context, FreshContext}
+import dotty.tools.dotc.core.StdNames._
+import dotty.tools.io.VirtualDirectory
+import dotty.tools.repl.AbstractFileClassLoader
+
+import scala.quoted.Expr
+import java.io.ByteArrayOutputStream
+import java.io.PrintStream
+import java.nio.charset.StandardCharsets
+
+class QuoteDriver extends Driver {
+
+  def run[T](expr: Expr[T]): T = {
+    val ctx: Context = initCtx.fresh
+    // TODO enable optimisation?
+    // ctx.settings.optimise.update(true)(ctx)
+
+    val outDir = new VirtualDirectory("(memory)", None)
+
+    new ExprCompiler(outDir).newRun(ctx).compileExpr(expr)
+
+    val classLoader = new AbstractFileClassLoader(outDir, this.getClass.getClassLoader)
+
+    val clazz = classLoader.loadClass(nme.QUOTE.toString)
+    val method = clazz.getMethod("apply")
+    val instance = clazz.newInstance()
+
+    method.invoke(instance).asInstanceOf[T]
+  }
+
+  def show(expr: Expr[_]): String = {
+    val ctx: Context = initCtx.fresh
+    ctx.settings.color.update("never")(ctx) // TODO support colored show
+    val baos = new ByteArrayOutputStream
+    var ps: PrintStream = null
+    try {
+      ps = new PrintStream(baos, true, "utf-8")
+
+      new ExprDecompiler(ps).newRun(ctx).compileExpr(expr)
+
+      new String(baos.toByteArray, StandardCharsets.UTF_8)
+    }
+    finally if (ps != null) ps.close()
+  }
+
+  override def initCtx: Context = {
+    val ictx = super.initCtx.fresh
+    val classpath = System.getProperty("java.class.path")
+    ictx.settings.classpath.update(classpath)(ictx)
+    ictx
+  }
+
+}

compiler/src/dotty/tools/dotc/quoted/QuotePrinter.scala

@@ -0,0 +1,17 @@
+package dotty.tools.dotc.quoted
+
+import java.io.PrintStream
+
+import dotty.tools.dotc.core.Contexts._
+import dotty.tools.dotc.core.Phases.Phase
+
+/** Pretty prints the compilation unit to an output stream */
+class QuotePrinter(out: PrintStream) extends Phase {
+
+  override def phaseName: String = "quotePrinter"
+
+  override def run(implicit ctx: Context): Unit = {
+    val unit = ctx.compilationUnit
+    out.print(unit.tpdTree.show)
+  }
+}

compiler/src/dotty/tools/dotc/quoted/Runners.scala

@@ -0,0 +1,30 @@
+package dotty.tools.dotc.quoted
+
+import dotty.tools.dotc.ast.Trees.Literal
+import dotty.tools.dotc.core.Constants.Constant
+import dotty.tools.dotc.printing.RefinedPrinter
+
+import scala.quoted.Expr
+import scala.quoted.Liftable.ConstantExpr
+import scala.runtime.quoted._
+
+/** Default runners for quoted expressions */
+object Runners {
+
+  implicit def runner[T]: Runner[T] = new Runner[T] {
+
+    def run(expr: Expr[T]): T = expr match {
+      case expr: ConstantExpr[T] => expr.value
+      case _ => new QuoteDriver().run(expr)
+    }
+
+    def show(expr: Expr[T]): String = expr match {
+      case expr: ConstantExpr[T] =>
+        val ctx = new QuoteDriver().initCtx
+        ctx.settings.color.update("never")(ctx)
+        val printer = new RefinedPrinter(ctx)
+        printer.toText(Literal(Constant(expr.value))).mkString(Int.MaxValue, false)
+      case _ => new QuoteDriver().show(expr)
+    }
+  }
+}

compiler/src/dotty/tools/dotc/transform/PostTyper.scala

@@ -180,6 +180,7 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
     override def transform(tree: Tree)(implicit ctx: Context): Tree =
       try tree match {
         case tree: Ident if !tree.isType =>
+          handleMeta(tree.symbol)
           tree.tpe match {
             case tpe: ThisType => This(tpe.cls).withPos(tree.pos)
             case _ => tree

compiler/src/dotty/tools/dotc/transform/Splicer.scala

@@ -24,7 +24,7 @@ object Splicer {
   /** Splice the Tree for a Quoted expression which is constructed via a reflective call to the given method */
   private def reflectiveSplice(tree: Tree)(implicit ctx: Context): Tree = {
     val interpreter = new Interpreter
-    interpreter.interpretTree[quoted.Expr[_]](tree).map(PickledQuotes.quotedToTree(_)).getOrElse(tree)
+    interpreter.interpretTree[scala.quoted.Expr[_]](tree).map(PickledQuotes.quotedToTree(_)).getOrElse(tree)
   }
 
 }

compiler/test/dotty/Jars.scala

@@ -14,6 +14,10 @@ object Jars {
   val dottyInterfaces: String = sys.env.get("DOTTY_INTERFACE")
     .getOrElse(Properties.dottyInterfaces)
 
+  /** Scala asm Jar */
+  lazy val scalaAsm: String =
+    findJarFromRuntime("scala-asm-6.0.0-scala-1")
+
   /** Dotty extras classpath from env or properties */
   val dottyExtras: List[String] = sys.env.get("DOTTY_EXTRAS")
     .map(_.split(":").toList).getOrElse(Properties.dottyExtras)
@@ -25,6 +29,10 @@ object Jars {
   val dottyTestDeps: List[String] =
     dottyLib :: dottyCompiler :: dottyInterfaces :: dottyExtras
 
+  /** Dotty runtime with compiler dependencies, used for quoted.Expr.run */
+  val dottyRunWithCompiler: List[String] =
+    dottyLib :: dottyCompiler :: dottyInterfaces :: scalaAsm :: Nil
+
   def scalaLibrary: String = sys.env.get("DOTTY_SCALA_LIBRARY")
     .getOrElse(findJarFromRuntime("scala-library-2."))