Merge pull request scala#4452 from lrytz/valueClassSelfTypeBCode

adriaanm · adriaanm · commit 20f7389c4cb2 · 2015-04-22T17:10:57.000-07:00
Don't crash GenBCode for value classes with a self declaration
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeAsmCommon.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeAsmCommon.scala
@@ -329,10 +329,12 @@ final class BCodeAsmCommon[G <: Global](val global: G) {
    * Build the [[InlineInfo]] for a class symbol.
    */
   def buildInlineInfoFromClassSymbol(classSym: Symbol, classSymToInternalName: Symbol => InternalName, methodSymToDescriptor: Symbol => String): InlineInfo = {
-    val selfType = {
+    val traitSelfType = if (classSym.isTrait && !classSym.isImplClass) {
       // The mixin phase uses typeOfThis for the self parameter in implementation class methods.
       val selfSym = classSym.typeOfThis.typeSymbol
       if (selfSym != classSym) Some(classSymToInternalName(selfSym)) else None
+    } else {
+      None
     }
 
     val isEffectivelyFinal = classSym.isEffectivelyFinal
@@ -394,6 +396,6 @@ final class BCodeAsmCommon[G <: Global](val global: G) {
         }
     }).toMap
 
-    InlineInfo(selfType, isEffectivelyFinal, methodInlineInfos, warning)
+    InlineInfo(traitSelfType, isEffectivelyFinal, methodInlineInfos, warning)
   }
 }
diff --git a/test/files/run/valueClassSelfType.scala b/test/files/run/valueClassSelfType.scala
@@ -0,0 +1,52 @@
+trait T
+
+class V1(val l: Long) extends AnyVal { self: T =>
+  def foo: V1 = self
+  def bar: T  = self
+}
+
+class V2(val l: Long) extends AnyVal { self =>
+  def foo: V2 = self
+}
+
+class V3(val l: Long) extends AnyVal { self: Long =>
+  def foo: V3   = self
+  def bar: Long = self
+}
+
+// non-value classes
+
+class C1(val l: Long) { self: T =>
+  def foo: C1 = self
+  def bar: T  = self
+}
+
+class C2(val l: Long) { self =>
+  def foo: C2 = self
+}
+
+class C3(val l: Long) { self: Long =>
+  def foo: C3   = self
+  def bar: Long = self
+}
+
+object Test extends App {
+  // Rejected: superclass V1 is not a subclass of the superclass Object of the mixin trait T
+  // new V1(1l) with T
+
+  assert(new V2(1l).foo.l == 1l)
+
+  // Rejected: V3 does not conform to its self-type V3 with Long
+  // new V3(1l)
+
+  val c2 = new C1(2l) with T
+  assert(c2.foo.l + c2.bar.asInstanceOf[C1].l == 4l)
+
+  assert(new C2(3l).foo.l == 3l)
+
+  // Rejected: C3 does not conform to its self-type C3 with Long
+  // new C3(4l)
+
+  // Rejected: class Long needs to be a trait to be mixed in
+  // new C3(4l) with Long
+}

Original file line number	Diff line number	Diff line change
`@@ -329,10 +329,12 @@ final class BCodeAsmCommon[G <: Global](val global: G) {`
`329`	`329`	`* Build the [[InlineInfo]] for a class symbol.`
`330`	`330`	`*/`
`331`	`331`	`def buildInlineInfoFromClassSymbol(classSym: Symbol, classSymToInternalName: Symbol => InternalName, methodSymToDescriptor: Symbol => String): InlineInfo = {`
`332`		`- val selfType = {`
	`332`	`+ val traitSelfType = if (classSym.isTrait && !classSym.isImplClass) {`
`333`	`333`	`// The mixin phase uses typeOfThis for the self parameter in implementation class methods.`
`334`	`334`	`val selfSym = classSym.typeOfThis.typeSymbol`
`335`	`335`	`if (selfSym != classSym) Some(classSymToInternalName(selfSym)) else None`
	`336`	`+ } else {`
	`337`	`+ None`
`336`	`338`	`}`
`337`	`339`
`338`	`340`	`val isEffectivelyFinal = classSym.isEffectivelyFinal`
`@@ -394,6 +396,6 @@ final class BCodeAsmCommon[G <: Global](val global: G) {`
`394`	`396`	`}`
`395`	`397`	`}).toMap`
`396`	`398`
`397`		`- InlineInfo(selfType, isEffectivelyFinal, methodInlineInfos, warning)`
	`399`	`+ InlineInfo(traitSelfType, isEffectivelyFinal, methodInlineInfos, warning)`
`398`	`400`	`}`
`399`	`401`	`}`