Merge pull request #6700 from dotty-staging/add-quote-context

Add quote context

Author: nicolasstucki

community-build/community-projects/scalatest

@@ -773,6 +773,7 @@ class Definitions {
     @threadUnsafe lazy val InternalQuoted_patternHoleR: TermRef = InternalQuotedModule.requiredMethodRef("patternHole")
     def InternalQuoted_patternHole(implicit ctx: Context): Symbol = InternalQuoted_patternHoleR.symbol
     @threadUnsafe lazy val InternalQuoted_patternBindHoleAnnot: ClassSymbol = InternalQuotedModule.requiredClass("patternBindHole")
+    @threadUnsafe lazy val InternalQuoted_QuoteTypeTagAnnot: ClassSymbol = InternalQuotedModule.requiredClass("quoteTypeTag")
 
   @threadUnsafe lazy val InternalQuotedMatcherModuleRef: TermRef = ctx.requiredModuleRef("scala.internal.quoted.Matcher")
     def InternalQuotedMatcherModule(implicit ctx: Context): Symbol = InternalQuotedMatcherModuleRef.symbol

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -3,9 +3,7 @@ package dotty.tools.dotc.quoted
 import dotty.tools.dotc.CompilationUnit
 import dotty.tools.dotc.util.NoSource
 
-import scala.quoted.Expr
+import scala.quoted._
 
 /* Compilation unit containing the contents of a quoted expression */
-class ExprCompilationUnit(val expr: Expr[_]) extends CompilationUnit(NoSource) {
-  override def toString: String = s"Expr($expr)"
-}
+class ExprCompilationUnit(val exprBuilder: QuoteContext => Expr[_]) extends CompilationUnit(NoSource)

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

@@ -14,20 +14,26 @@ 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.tastyreflect.ReflectionImpl
 import dotty.tools.dotc.transform.Staging
 import dotty.tools.dotc.util.Spans.Span
 import dotty.tools.dotc.util.SourceFile
 import dotty.tools.io.{Path, VirtualFile}
 
-import scala.quoted.{Expr, Type}
+import scala.annotation.tailrec
+import scala.concurrent.Promise
+import scala.quoted.{Expr, QuoteContext, Type}
 
 /** Compiler that takes the contents of a quoted expression `expr` and produces
  *  a class file with `class ' { def apply: Object = expr }`.
  */
 class QuoteCompiler extends Compiler {
 
+  /** Either `Left` with name of the classfile generated or `Right` with the value contained in the expression */
+  private[this] var result: Either[String, Any] = null
+
   override protected def frontendPhases: List[List[Phase]] =
-    List(List(new QuotedFrontend(putInClass = true)))
+    List(List(new QuotedFrontend))
 
   override protected def picklerPhases: List[List[Phase]] =
     List(List(new Staging))
@@ -40,58 +46,67 @@ class QuoteCompiler extends Compiler {
   def outputClassName: TypeName = "Generated$Code$From$Quoted".toTypeName
 
   /** Frontend that receives a scala.quoted.Expr or scala.quoted.Type as input */
-  class QuotedFrontend(putInClass: Boolean) extends Phase {
+  class QuotedFrontend extends Phase {
     import tpd._
 
+
     def phaseName: String = "quotedFrontend"
 
     override def runOn(units: List[CompilationUnit])(implicit ctx: Context): List[CompilationUnit] = {
-      units.map {
+      units.flatMap {
         case exprUnit: ExprCompilationUnit =>
-          val tree =
-            if (putInClass) inClass(exprUnit.expr)
-            else PickledQuotes.quotedExprToTree(exprUnit.expr)
-          val source = SourceFile.virtual("<quoted.Expr>", "")
-          CompilationUnit(source, tree, forceTrees = true)
-        case typeUnit: TypeCompilationUnit =>
-          assert(!putInClass)
-          val tree = PickledQuotes.quotedTypeToTree(typeUnit.tpe)
-          val source = SourceFile.virtual("<quoted.Type>", "")
-          CompilationUnit(source, tree, forceTrees = true)
+          val pos = Span(0)
+          val assocFile = new VirtualFile("<quote>")
+
+          // Places the contents of expr in a compilable tree for a class with the following format.
+          // `package __root__ { class ' { def apply: Any = <expr> } }`
+          val cls = ctx.newCompleteClassSymbol(defn.RootClass, outputClassName, 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.quotedExprToTree(checkValidRunExpr(exprUnit.exprBuilder.apply(new QuoteContext(ReflectionImpl(ctx)))))(ctx.withOwner(meth))
+
+          getLiteral(quoted) match {
+            case Some(value) =>
+              result = Right(value)
+              None // Stop copilation here we already have the result
+            case None =>
+              val run = DefDef(meth, quoted)
+              val classTree = ClassDef(cls, DefDef(cls.primaryConstructor.asTerm), run :: Nil)
+              val tree = PackageDef(ref(defn.RootPackage).asInstanceOf[Ident], classTree :: Nil).withSpan(pos)
+              val source = SourceFile.virtual("<quoted.Expr>", "")
+              result = Left(outputClassName.toString)
+              Some(CompilationUnit(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 = Span(0)
-      val assocFile = new VirtualFile("<quote>")
-
-      val cls = ctx.newCompleteClassSymbol(defn.RootClass, outputClassName, 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.quotedExprToTree(expr)(ctx.withOwner(meth))
+    private def checkValidRunExpr(expr: Expr[_]): Expr[_] = expr match {
+      case expr: scala.internal.quoted.TastyTreeExpr[Tree] @unchecked =>
+        throw new Exception("Cannot call `Expr.run` on an `Expr` that comes from a macro argument.")
+      case _ => expr
+    }
 
-      val run = DefDef(meth, quoted)
-      val classTree = ClassDef(cls, DefDef(cls.primaryConstructor.asTerm), run :: Nil)
-      PackageDef(ref(defn.RootPackage).asInstanceOf[Ident], classTree :: Nil).withSpan(pos)
+    /** Get the literal value if this tree only contains a literal tree */
+    @tailrec private def getLiteral(tree: Tree): Option[Any] = tree match {
+      case Literal(lit) => Some(lit.value)
+      case Block(Nil, expr) => getLiteral(expr)
+      case Inlined(_, Nil, expr) => getLiteral(expr)
+      case _ => None
     }
 
     def run(implicit ctx: Context): Unit = unsupported("run")
   }
 
-  class ExprRun(comp: Compiler, ictx: Context) extends Run(comp, ictx) {
-    def compileExpr(expr: Expr[_]): Unit = {
-      val units = new ExprCompilationUnit(expr) :: Nil
-      compileUnits(units)
-    }
-    def compileType(tpe: Type[_]): Unit = {
-      val units = new TypeCompilationUnit(tpe) :: Nil
+  class ExprRun(comp: QuoteCompiler, ictx: Context) extends Run(comp, ictx) {
+    /** Unpickle and optionally compile the expression.
+     *  Returns either `Left` with name of the classfile generated or `Right` with the value contained in the expression.
+     */
+    def compileExpr(exprBuilder:  QuoteContext => Expr[_]): Either[String, Any] = {
+      val units = new ExprCompilationUnit(exprBuilder) :: Nil
       compileUnits(units)
+      result
     }
   }
 }

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

@@ -7,7 +7,7 @@ import dotty.tools.dotc.tastyreflect.ReflectionImpl
 import dotty.tools.io.{AbstractFile, Directory, PlainDirectory, VirtualDirectory}
 import dotty.tools.repl.AbstractFileClassLoader
 import dotty.tools.dotc.reporting._
-import scala.quoted.{Expr, Type}
+import scala.quoted._
 import scala.quoted.Toolbox
 import java.net.URLClassLoader
 
@@ -20,7 +20,7 @@ class QuoteDriver(appClassloader: ClassLoader) extends Driver {
 
   private[this] val contextBase: ContextBase = new ContextBase
 
-  def run[T](expr: Expr[T], settings: Toolbox.Settings): T = {
+  def run[T](exprBuilder: QuoteContext => Expr[T], settings: Toolbox.Settings): T = {
     val outDir: AbstractFile = settings.outDir match {
       case Some(out) =>
         val dir = Directory(out)
@@ -33,56 +33,21 @@ class QuoteDriver(appClassloader: ClassLoader) extends Driver {
     val (_, ctx0: Context) = setup(settings.compilerArgs.toArray :+ "dummy.scala", initCtx.fresh)
     val ctx = setToolboxSettings(ctx0.fresh.setSetting(ctx0.settings.outputDir, outDir), settings)
 
-    val driver = new QuoteCompiler
-    driver.newRun(ctx).compileExpr(expr)
+    new QuoteCompiler().newRun(ctx).compileExpr(exprBuilder) match {
+      case Right(value) =>
+        value.asInstanceOf[T]
 
-    assert(!ctx.reporter.hasErrors)
+      case Left(classname) =>
+        assert(!ctx.reporter.hasErrors)
 
-    val classLoader = new AbstractFileClassLoader(outDir, appClassloader)
+        val classLoader = new AbstractFileClassLoader(outDir, appClassloader)
 
-    val clazz = classLoader.loadClass(driver.outputClassName.toString)
-    val method = clazz.getMethod("apply")
-    val inst = clazz.getConstructor().newInstance()
+        val clazz = classLoader.loadClass(classname)
+        val method = clazz.getMethod("apply")
+        val inst = clazz.getConstructor().newInstance()
 
-    method.invoke(inst).asInstanceOf[T]
-  }
-
-  private def doShow(tree: Tree, ctx: Context): String = {
-    implicit val c: Context = ctx
-    val tree1 =
-      if (ctx.settings.YshowRawQuoteTrees.value) tree
-      else (new TreeCleaner).transform(tree)
-    ReflectionImpl.showTree(tree1)
-  }
-
-  def show(expr: Expr[_], settings: Toolbox.Settings): String =
-    withTree(expr, doShow, settings)
-
-  def show(tpe: Type[_], settings: Toolbox.Settings): String =
-    withTypeTree(tpe, doShow, settings)
-
-  def withTree[T](expr: Expr[_], f: (Tree, Context) => T, settings: Toolbox.Settings): T = {
-    val ctx = setToolboxSettings(setup(settings.compilerArgs.toArray :+ "dummy.scala", initCtx.fresh)._2.fresh, settings)
-
-    var output: Option[T] = None
-    def registerTree(tree: tpd.Tree)(ctx: Context): Unit = {
-      assert(output.isEmpty)
-      output = Some(f(tree, ctx))
-    }
-    new QuoteDecompiler(registerTree).newRun(ctx).compileExpr(expr)
-    output.getOrElse(throw new Exception("Could not extract " + expr))
-  }
-
-  def withTypeTree[T](tpe: Type[_], f: (TypTree, Context) => T, settings: Toolbox.Settings): T = {
-    val ctx = setToolboxSettings(setup(settings.compilerArgs.toArray :+ "dummy.scala", initCtx.fresh)._2.fresh, settings)
-
-    var output: Option[T] = None
-    def registerTree(tree: tpd.Tree)(ctx: Context): Unit = {
-      assert(output.isEmpty)
-      output = Some(f(tree.asInstanceOf[TypTree], ctx))
+        method.invoke(inst).asInstanceOf[T]
     }
-    new QuoteDecompiler(registerTree).newRun(ctx).compileType(tpe)
-    output.getOrElse(throw new Exception("Could not extract " + tpe))
   }
 
   override def initCtx: Context = {
@@ -92,7 +57,6 @@ class QuoteDriver(appClassloader: ClassLoader) extends Driver {
   }
 
   private def setToolboxSettings(ctx: FreshContext, settings: Toolbox.Settings): ctx.type = {
-    ctx.setSetting(ctx.settings.color, if (settings.color) "always" else "never")
     ctx.setSetting(ctx.settings.YshowRawQuoteTrees, settings.showRawTree)
     // An error in the generated code is a bug in the compiler
     // Setting the throwing reporter however will report any exception

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

@@ -1,13 +1,9 @@
 package dotty.tools.dotc.quoted
 
-import dotty.tools.dotc.ast.tpd
-
 import scala.quoted._
-import scala.internal.quoted.{LiftedExpr, TastyTreeExpr}
 
 /** Default runners for quoted expressions */
 object ToolboxImpl {
-  import tpd._
 
   /** Create a new instance of the toolbox using the the classloader of the application.
     *
@@ -19,18 +15,10 @@ object ToolboxImpl {
 
     private[this] val driver: QuoteDriver = new QuoteDriver(appClassloader)
 
-    def run[T](expr: Expr[T]): T = expr match {
-      case expr: LiftedExpr[T] =>
-        expr.value
-      case expr: TastyTreeExpr[Tree] @unchecked =>
-        throw new Exception("Cannot call `Expr.run` on an `Expr` that comes from a macro argument.")
-      case _ =>
-        synchronized(driver.run(expr, settings))
+    def run[T](exprBuilder: QuoteContext => Expr[T]): T = synchronized {
+      driver.run(exprBuilder, settings)
     }
 
-    def show[T](expr: Expr[T]): String = synchronized(driver.show(expr, settings))
-
-    def show[T](tpe: Type[T]): String = synchronized(driver.show(tpe, settings))
   }
 
 }