src/java.base/share/classes/java/lang/invoke/LambdaFormEditor.java

*** 385,394 ****
--- 385,402 ----
      }
      private BoundMethodHandle.SpeciesData newSpeciesData(BasicType type) {
          return oldSpeciesData().extendWith(type);
      }
  
+     BoundMethodHandle bindArgumentQ(BoundMethodHandle mh, int pos, Object value, MethodHandle unbox) {
+         assert(mh.speciesData() == oldSpeciesData());
+         BasicType bt = Q_TYPE;
+         MethodType type2 = bindArgumentType(mh, pos, bt);
+         LambdaForm form2 = bindArgumentForm(1+pos);
+         return mh.copyWithExtendL(type2, form2, value)
+                  .copyWithExtendL(type2, form2, unbox);
+     }
      BoundMethodHandle bindArgumentL(BoundMethodHandle mh, int pos, Object value) {
          assert(mh.speciesData() == oldSpeciesData());
          BasicType bt = L_TYPE;
          MethodType type2 = bindArgumentType(mh, pos, bt);
          LambdaForm form2 = bindArgumentForm(1+pos);
*** 445,466 ****
          }
          LambdaFormBuffer buf = buffer();
          buf.startEdit();
  
          BoundMethodHandle.SpeciesData oldData = oldSpeciesData();
!         BoundMethodHandle.SpeciesData newData = newSpeciesData(lambdaForm.parameterType(pos));
          Name oldBaseAddress = lambdaForm.parameter(0);  // BMH holding the values
          Name newBaseAddress;
          NamedFunction getter = newData.getterFunction(oldData.fieldCount());
  
          if (pos != 0) {
              // The newly created LF will run with a different BMH.
              // Switch over any pre-existing BMH field references to the new BMH class.
              buf.replaceFunctions(oldData.getterFunctions(), newData.getterFunctions(), oldBaseAddress);
              newBaseAddress = oldBaseAddress.withConstraint(newData);
              buf.renameParameter(0, newBaseAddress);
              buf.replaceParameterByNewExpression(pos, new Name(getter, newBaseAddress));
          } else {
              // cannot bind the MH arg itself, unless oldData is empty
              assert(oldData == BoundMethodHandle.SpeciesData.EMPTY);
              newBaseAddress = new Name(L_TYPE).withConstraint(newData);
              buf.replaceParameterByNewExpression(0, new Name(getter, newBaseAddress));
--- 453,491 ----
          }
          LambdaFormBuffer buf = buffer();
          buf.startEdit();
  
          BoundMethodHandle.SpeciesData oldData = oldSpeciesData();
!         BasicType ptype = lambdaForm.parameterType(pos);
!         BoundMethodHandle.SpeciesData newData = (ptype != Q_TYPE) ? newSpeciesData(ptype)
!                                                                   : oldData.extendWith(L_TYPE).extendWith(L_TYPE); // value + unbox MH
          Name oldBaseAddress = lambdaForm.parameter(0);  // BMH holding the values
          Name newBaseAddress;
          NamedFunction getter = newData.getterFunction(oldData.fieldCount());
  
          if (pos != 0) {
              // The newly created LF will run with a different BMH.
              // Switch over any pre-existing BMH field references to the new BMH class.
              buf.replaceFunctions(oldData.getterFunctions(), newData.getterFunctions(), oldBaseAddress);
              newBaseAddress = oldBaseAddress.withConstraint(newData);
              buf.renameParameter(0, newBaseAddress);
+             if (ptype == Q_TYPE) {
+                 // Q-types are stored in boxed form. Unboxing step is required.
+                 int exprPos = lambdaForm.arity();
+                 int UNBOX_MH      = exprPos++;
+                 int BOXED_VALUE   = exprPos++;
+                 int UNBOXED_VALUE = exprPos++;
+                 NamedFunction unboxGetter = newData.getterFunction(oldData.fieldCount()+1);
+                 buf.insertExpression(UNBOX_MH, new Name(unboxGetter, newBaseAddress));
+                 buf.insertExpression(BOXED_VALUE, new Name(getter, newBaseAddress));
+                 MethodType unboxInvokerType = MethodType.methodType(Q_TYPE.basicTypeClass(), L_TYPE.basicTypeClass());
+                 Name unbox = new Name(unboxInvokerType, buf.name(UNBOX_MH), buf.name(BOXED_VALUE));
+                 buf.insertExpression(UNBOXED_VALUE, unbox);
+                 buf.replaceParameterByCopy(pos, UNBOXED_VALUE);
+             } else {
                  buf.replaceParameterByNewExpression(pos, new Name(getter, newBaseAddress));
+             }
          } else {
              // cannot bind the MH arg itself, unless oldData is empty
              assert(oldData == BoundMethodHandle.SpeciesData.EMPTY);
              newBaseAddress = new Name(L_TYPE).withConstraint(newData);
              buf.replaceParameterByNewExpression(0, new Name(getter, newBaseAddress));