skipping unnecessary work in GenASM when emitting 1.5 classfiles

1 files changed, 6 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala b/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala
index 99832d1327..b8cf4eca9f 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala
@@ -433,10 +433,11 @@ abstract class GenASM extends SubComponent with BytecodeWriters {
   }

 

   private val majorVersion: Int = (classfileVersion & 0xFF)

+  private val emitStackMapFrame = (majorVersion >= 50)

 

   private val extraProc: Int = mkFlags(

     asm.ClassWriter.COMPUTE_MAXS,

-    if(majorVersion >= 50) asm.ClassWriter.COMPUTE_FRAMES else 0

+    if(emitStackMapFrame) asm.ClassWriter.COMPUTE_FRAMES else 0

   )

 

   val JAVA_LANG_OBJECT = asm.Type.getObjectType("java/lang/Object")

@@ -580,14 +581,14 @@ abstract class GenASM extends SubComponent with BytecodeWriters {
         else                 { sym.javaSimpleName }

       })

 

-      if(hasInternalName) {

+      if(emitStackMapFrame && hasInternalName) {

         val internalName = cachedJN.toString()

         val trackedSym = jsymbol(sym)

         reverseJavaName.get(internalName) match {

           case None         =>

             reverseJavaName.put(internalName, trackedSym)

           case Some(oldsym) =>

-            assert((oldsym == trackedSym) || List(RuntimeNothingClass, RuntimeNullClass).contains(oldsym), // NothingClass, NullClass,

+            assert((oldsym == trackedSym) || (oldsym == RuntimeNothingClass) || (oldsym == RuntimeNullClass), // In contrast, neither NothingClass nor NullClass show up bytecode-level.

                    "how can getCommonSuperclass() do its job if different class symbols get the same bytecode-level internal name.")

         }

       }

@@ -2728,7 +2729,7 @@ abstract class GenASM extends SubComponent with BytecodeWriters {
           // TODO Logical's 2nd elem should be declared ValueTypeKind, to better approximate its allowed values (isIntSized, its comments appears to convey)

           // TODO GenICode uses `toTypeKind` to define that elem, `toValueTypeKind` would be needed instead.

           // TODO How about adding some asserts to Logical and similar ones to capture the remaining constraint (UNIT not allowed).

-          case Logical(op, kind) => (op, kind) match {

+          case Logical(op, kind) => ((op, kind): @unchecked) match {

             case (AND, LONG) => emit(Opcodes.LAND)

             case (AND, INT)  => emit(Opcodes.IAND)

             case (AND, _)    =>

@@ -2748,7 +2749,7 @@ abstract class GenASM extends SubComponent with BytecodeWriters {
               if (kind != BOOL) { emitT2T(INT, kind) }

           }

 

-          case Shift(op, kind) => (op, kind) match {

+          case Shift(op, kind) => ((op, kind): @unchecked) match {

             case (LSL, LONG) => emit(Opcodes.LSHL)

             case (LSL, INT)  => emit(Opcodes.ISHL)

             case (LSL, _) =>