src/share/classes/java/lang/invoke/MethodHandleImpl.java

rev 9328 : 8027827: Improve performance of catchException combinator
8034120: MethodHandles.catchException doesn't handle VarargsCollector right
Reviewed-by: lagergren, psandoz, ?
rev 9329 : 8033666: Make sure @ForceInline is everywhere it needs to be in sun.misc and java.lang.invoke
Reviewed-by: ?

*** 251,261 ****
                  } else {
                      // Simple reference conversion.
                      // Note:  Do not check for a class hierarchy relation
                      // between src and dst.  In all cases a 'null' argument
                      // will pass the cast conversion.
!                     fn = ValueConversions.cast(dst);
                  }
              }
              Name conv = new Name(fn, names[INARG_BASE + i]);
              assert(names[nameCursor] == null);
              names[nameCursor++] = conv;
--- 251,261 ----
                  } else {
                      // Simple reference conversion.
                      // Note:  Do not check for a class hierarchy relation
                      // between src and dst.  In all cases a 'null' argument
                      // will pass the cast conversion.
!                     fn = ValueConversions.cast(dst, Lazy.MH_castReference);
                  }
              }
              Name conv = new Name(fn, names[INARG_BASE + i]);
              assert(names[nameCursor] == null);
              names[nameCursor++] = conv;
*** 291,300 ****
--- 291,319 ----
  
          LambdaForm form = new LambdaForm("convert", lambdaType.parameterCount(), names);
          return SimpleMethodHandle.make(srcType, form);
      }
  
+     /**
+      * Identity function, with reference cast.
+      * @param t an arbitrary reference type
+      * @param x an arbitrary reference value
+      * @return the same value x
+      */
+     @ForceInline
+     @SuppressWarnings("unchecked")
+     static <T,U> T castReference(Class<? extends T> t, U x) {
+         // inlined Class.cast because we can't ForceInline it
+         if (x != null && !t.isInstance(x))
+             throw newClassCastException(t, x);
+         return (T) x;
+     }
+ 
+     private static ClassCastException newClassCastException(Class<?> t, Object obj) {
+         return new ClassCastException("Cannot cast " + obj.getClass().getName() + " to " + t.getName());
+     }
+ 
      static MethodHandle makeReferenceIdentity(Class<?> refType) {
          MethodType lambdaType = MethodType.genericMethodType(1).invokerType();
          Name[] names = arguments(1, lambdaType);
          names[names.length - 1] = new Name(ValueConversions.identity(), names[1]);
          LambdaForm form = new LambdaForm("identity", lambdaType.parameterCount(), names);
*** 486,495 ****
--- 505,516 ----
          static final NamedFunction NF_checkSpreadArgument;
          static final NamedFunction NF_guardWithCatch;
          static final NamedFunction NF_selectAlternative;
          static final NamedFunction NF_throwException;
  
+         static final MethodHandle MH_castReference;
+ 
          static {
              try {
                  NF_checkSpreadArgument = new NamedFunction(MHI.getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
                  NF_guardWithCatch      = new NamedFunction(MHI.getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class,
                          MethodHandle.class, Object[].class));
*** 499,508 ****
--- 520,532 ----
  
                  NF_checkSpreadArgument.resolve();
                  NF_guardWithCatch.resolve();
                  NF_selectAlternative.resolve();
                  NF_throwException.resolve();
+ 
+                 MethodType mt = MethodType.methodType(Object.class, Class.class, Object.class);
+                 MH_castReference = IMPL_LOOKUP.findStatic(MHI, "castReference", mt);
              } catch (ReflectiveOperationException ex) {
                  throw newInternalError(ex);
              }
          }
      }