SI-9359 Fix InnerClass entry flags for nested Java enums

The access flags in InnerClass entries for nested Java enums were
basically completely off.

A first step is to use the recently introduced backend method
`javaClassfileFlags`, which is now moved to BCodeAsmCommon.
See its doc for an explanation.

Then the flags of the enum class symbol were off. An enum is
  - final if none of its values has a class body
  - abstract if it has an abstract method
(https://docs.oracle.com/javase/specs/jls/se7/html/jls-8.html#jls-8.9)

When using the ClassfileParser:
  - ENUM was never added. I guess that's just an oversight.
  - ABSTRACT (together with SEALED) was always added. This is to
    enable exhaustiveness checking, see 3f7b8b5. This is a hack and we
    have to go through the class members in the backend to find out if
    the enum actually has the `ACC_ABSTRACT` flag or not.

When using the JavaParser:
  - FINAL was never added.
  - ABSTRACT was never added.

This commit fixes all of the above and tests cases (Java enum read
from the classfile and from source).

1 files changed, 0 insertions, 29 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala b/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala
index fffb9286b8..93734d3935 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala
@@ -213,35 +213,6 @@ class BTypesFromSymbols[G <: Global](val global: G) extends BTypes {
     assert(!primitiveTypeMap.contains(sym) || isCompilingPrimitive, sym)
   }
 
-  /**
-   * Reconstruct the classfile flags from a Java defined class symbol.
-   *
-   * The implementation of this method is slightly different that [[javaFlags]]. The javaFlags
-   * method is primarily used to map Scala symbol flags to sensible classfile flags that are used
-   * in the generated classfiles. For example, all classes emitted by the Scala compiler have
-   * ACC_PUBLIC.
-   *
-   * When building a [[ClassBType]] from a Java class symbol, the flags in the type's `info` have
-   * to correspond exactly to the flags in the classfile. For example, if the class is package
-   * protected (i.e., it doesn't have the ACC_PUBLIC flag), this needs to be reflected in the
-   * ClassBType. For example, the inliner needs the correct flags for access checks.
-   *
-   * Class flags are listed here:
-   *   https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.1-200-E.1
-   */
-  private def javaClassfileFlags(classSym: Symbol): Int = {
-    assert(classSym.isJava, s"Expected Java class symbol, got ${classSym.fullName}")
-    import asm.Opcodes._
-    GenBCode.mkFlags(
-      if (classSym.isPublic)        ACC_PUBLIC    else 0,
-      if (classSym.isFinal)         ACC_FINAL     else 0,
-      if (classSym.isInterface)     ACC_INTERFACE else ACC_SUPER, // see the link above. javac does the same: ACC_SUPER for all classes, but not interfaces.
-      if (classSym.hasAbstractFlag) ACC_ABSTRACT  else 0,
-      if (classSym.isArtifact)      ACC_SYNTHETIC else 0,
-      if (classSym.hasEnumFlag)     ACC_ENUM      else 0
-    )
-  }
-
   private def setClassInfo(classSym: Symbol, classBType: ClassBType): ClassBType = {
     val superClassSym = if (classSym.isImplClass) ObjectClass else classSym.superClass
     assert(