Merge pull request #1148 from sjrd/scalajs-gen-exprs

Implement most of the Scala.js IR code generator.

3 files changed, 17 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/config/JavaPlatform.scala b/src/dotty/tools/dotc/config/JavaPlatform.scala
index 432a9a0b7..433b5b3f0 100644
--- a/src/dotty/tools/dotc/config/JavaPlatform.scala
+++ b/src/dotty/tools/dotc/config/JavaPlatform.scala
@@ -7,6 +7,7 @@ import ClassPath.{ JavaContext, DefaultJavaContext }
 import core._
 import Symbols._, Types._, Contexts._, Denotations._, SymDenotations._, StdNames._, Names._
 import Flags._, Scopes._, Decorators._, NameOps._, util.Positions._
+import transform.ExplicitOuter, transform.SymUtils._
 
 class JavaPlatform extends Platform {
 
@@ -38,6 +39,14 @@ class JavaPlatform extends Platform {
 
   def rootLoader(root: TermSymbol)(implicit ctx: Context): SymbolLoader = new ctx.base.loaders.PackageLoader(root, classPath)
 
+  /** Is the SAMType `cls` also a SAM under the rules of the JVM? */
+  def isSam(cls: ClassSymbol)(implicit ctx: Context): Boolean =
+    cls.is(NoInitsTrait) &&
+    cls.superClass == defn.ObjectClass &&
+    cls.directlyInheritedTraits.forall(_.is(NoInits)) &&
+    !ExplicitOuter.needsOuterIfReferenced(cls) &&
+    cls.typeRef.fields.isEmpty // Superaccessors already show up as abstract methods here, so no test necessary
+
   /** We could get away with excluding BoxedBooleanClass for the
    *  purpose of equality testing since it need not compare equal
    *  to anything but other booleans, but it should be present in
diff --git a/src/dotty/tools/dotc/config/Platform.scala b/src/dotty/tools/dotc/config/Platform.scala
index 972892d12..062d9002d 100644
--- a/src/dotty/tools/dotc/config/Platform.scala
+++ b/src/dotty/tools/dotc/config/Platform.scala
@@ -27,6 +27,9 @@ abstract class Platform {
   /** Any platform-specific phases. */
   //def platformPhases: List[SubComponent]
 
+  /** Is the SAMType `cls` also a SAM under the rules of the platform? */
+  def isSam(cls: ClassSymbol)(implicit ctx: Context): Boolean
+
   /** The various ways a boxed primitive might materialize at runtime. */
   def isMaybeBoxed(sym: ClassSymbol)(implicit ctx: Context): Boolean
 
diff --git a/src/dotty/tools/dotc/config/SJSPlatform.scala b/src/dotty/tools/dotc/config/SJSPlatform.scala
index fec9c25a1..3ec8049ae 100644
--- a/src/dotty/tools/dotc/config/SJSPlatform.scala
+++ b/src/dotty/tools/dotc/config/SJSPlatform.scala
@@ -2,6 +2,7 @@ package dotty.tools.dotc.config
 
 import dotty.tools.dotc.core._
 import Contexts._
+import Symbols._
 
 import dotty.tools.backend.sjs.JSDefinitions
 
@@ -10,4 +11,8 @@ class SJSPlatform()(implicit ctx: Context) extends JavaPlatform {
   /** Scala.js-specific definitions. */
   val jsDefinitions: JSDefinitions = new JSDefinitions()
 
+  /** Is the SAMType `cls` also a SAM under the rules of the Scala.js back-end? */
+  override def isSam(cls: ClassSymbol)(implicit ctx: Context): Boolean =
+    defn.isFunctionClass(cls) || jsDefinitions.isJSFunctionClass(cls)
+
 }