7013417: JSR 292 needs to support variadic method handle calls

Summary: Implement MH.asVarargsCollector, etc., and remove withTypeHandler.
Reviewed-by: twisti

src/share/classes/java/dyn/MethodHandle.java

 /*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -134,6 +134,11 @@ import static sun.dyn.MemberName.newIllegalArgumentException;  // utility
  * constant pool entry.
  * For more details, see the <a href="package-summary.html#mhcon">package summary</a>.)
  * <p>
+ * Method handles produced by lookups or constant loads from methods or
+ * constructors with the variable arity modifier bit ({@code 0x0080})
+ * have a corresponding variable arity, as if they were defined with
+ * the help of {@link #asVarargsCollector asVarargsCollector}.
+ * <p>
  * Java code can also use a reflective API called
  * {@link java.dyn.MethodHandles.Lookup MethodHandles.Lookup}
  * for creating and calling method handles.
@@ -175,6 +180,9 @@ assert(s.equals("savvy"));
 // mt is {Object[] =&gt; List}
 mt = MethodType.methodType(java.util.List.class, Object[].class);
 mh = lookup.findStatic(java.util.Arrays.class, "asList", mt);
+assert(mh.isVarargsCollector());
+x = mh.invokeGeneric("one", "two");
+assert(x.equals(java.util.Arrays.asList("one","two")));
 // mt is {(Object,Object,Object) =&gt; Object}
 mt = MethodType.genericMethodType(3);
 mh = MethodHandles.collectArguments(mh, mt);
@@ -306,26 +314,6 @@ public abstract class MethodHandle
         });
     }
 
-    /**
-     * Returns a string representation of the method handle,
-     * starting with the string {@code "MethodHandle"} and
-     * ending with the string representation of the method handle's type.
-     * In other words, this method returns a string equal to the value of:
-     * <blockquote><pre>
-     * "MethodHandle" + type().toString()
-     * </pre></blockquote>
-     * <p>
-     * Note:  Future releases of this API may add further information
-     * to the string representation.
-     * Therefore, the present syntax should not be parsed by applications.
-     *
-     * @return a string representation of the method handle
-     */
-    @Override
-    public String toString() {
-        return MethodHandleImpl.getNameString(IMPL_TOKEN, this);
-    }
-
     /**
      * Invoke the method handle, allowing any caller signature, but requiring an exact signature match.
      * The signature at the call site of {@code invokeExact} must
@@ -338,7 +326,7 @@ public abstract class MethodHandle
 
     /**
      * Invoke the method handle, allowing any caller signature,
-     * and optionally performing conversions for arguments and return types.
+     * and optionally performing conversions on arguments and return values.
      * <p>
      * If the call site signature exactly matches this method handle's {@link #type type},
      * the call proceeds as if by {@link #invokeExact invokeExact}.
@@ -353,14 +341,13 @@ public abstract class MethodHandle
      * adaptations directly on the caller's arguments,
      * and call the target method handle according to its own exact type.
      * <p>
-     * If the method handle is equipped with a
-     * {@linkplain #withTypeHandler type handler}, the handler must produce
-     * an entry point of the call site's exact type.
-     * Otherwise, the signature at the call site of {@code invokeGeneric} must
-     * be a valid argument to the standard {@code asType} method.
+     * The signature at the call site of {@code invokeGeneric} must
+     * be a valid argument to the receivers {@code asType} method.
      * In particular, the caller must specify the same argument arity
-     * as the callee's type.
+     * as the callee's type,
+     * if the callee is not a {@linkplain #asVarargsCollector variable arity collector}.
      * @throws WrongMethodTypeException if the target's type cannot be adjusted to the caller's type signature
+     * @throws ClassCastException if the target's type can be adjusted to the caller, but a reference cast fails
      * @throws Throwable anything thrown by the underlying method propagates unchanged through the method handle call
      */
     public final native @PolymorphicSignature Object invokeGeneric(Object... args) throws Throwable;
@@ -400,14 +387,14 @@ public abstract class MethodHandle
      * <p>
      * This call is equivalent to the following code:
      * <p><blockquote><pre>
-     * MethodHandle invoker = MethodHandles.varargsInvoker(this.type(), 0);
+     * MethodHandle invoker = MethodHandles.spreadInvoker(this.type(), 0);
      * Object result = invoker.invokeExact(this, arguments);
      * </pre></blockquote>
      * @param arguments the arguments to pass to the target
      * @return the result returned by the target
      * @throws WrongMethodTypeException if the target's type cannot be adjusted to take the arguments
      * @throws Throwable anything thrown by the target method invocation
-     * @see MethodHandles#varargsInvoker
+     * @see MethodHandles#spreadInvoker
      */
     public final Object invokeWithArguments(Object... arguments) throws Throwable {
         int argc = arguments == null ? 0 : arguments.length;
@@ -456,7 +443,7 @@ public abstract class MethodHandle
         }
 
         // more than ten arguments get boxed in a varargs list:
-        MethodHandle invoker = MethodHandles.invokers(type).varargsInvoker(0);
+        MethodHandle invoker = invokers(type).spreadInvoker(0);
         return invoker.invokeExact(this, arguments);
     }
     /** Equivalent to {@code invokeWithArguments(arguments.toArray())}. */
@@ -488,13 +475,7 @@ public abstract class MethodHandle
      * to match up the caller's and callee's types.
      * <p>
      * This method is equivalent to {@link MethodHandles#convertArguments convertArguments},
-     * except for method handles produced by {@link #withTypeHandler withTypeHandler},
-     * in which case the specified type handler is used for calls to {@code asType}.
-     * <p>
-     * Note that the default behavior of {@code asType} only performs
-     * pairwise argument conversion and return value conversion.
-     * Because of this, unless the method handle has a type handler,
-     * the original type and new type must have the same number of arguments.
+     * except for variable arity method handles produced by {@link #asVarargsCollector asVarargsCollector}.
      *
      * @param newType the expected type of the new method handle
      * @return a method handle which delegates to {@code this} after performing
@@ -508,14 +489,16 @@ public abstract class MethodHandle
     }
 
     /**
-     * Produce a method handle which adapts, as its <i>target</i>,
+     * Make an adapter which accepts a trailing array argument
+     * and spreads its elements as positional arguments.
+     * The new method handle adapts, as its <i>target</i>,
      * the current method handle.  The type of the adapter will be
      * the same as the type of the target, except that the final
      * {@code arrayLength} parameters of the target's type are replaced
      * by a single array parameter of type {@code arrayType}.
      * <p>
      * If the array element type differs from any of the corresponding
-     * argument types on original target,
+     * argument types on the original target,
      * the original target is adapted to take the array elements directly,
      * as if by a call to {@link #asType asType}.
      * <p>
@@ -539,6 +522,7 @@ public abstract class MethodHandle
      * @throws IllegalArgumentException if target does not have at least
      *         {@code arrayLength} parameter types
      * @throws WrongMethodTypeException if the implied {@code asType} call fails
+     * @see #asCollector
      */
     public final MethodHandle asSpreader(Class<?> arrayType, int arrayLength) {
         Class<?> arrayElement = arrayType.getComponentType();
@@ -553,13 +537,15 @@ public abstract class MethodHandle
     }
 
     /**
-     * Produce a method handle which adapts, as its <i>target</i>,
+     * Make an adapter which accepts a given number of trailing
+     * positional arguments and collects them into an array argument.
+     * The new method handle adapts, as its <i>target</i>,
      * the current method handle.  The type of the adapter will be
      * the same as the type of the target, except that a single trailing
      * parameter (usually of type {@code arrayType}) is replaced by
      * {@code arrayLength} parameters whose type is element type of {@code arrayType}.
      * <p>
-     * If the array type differs from the final argument type on original target,
+     * If the array type differs from the final argument type on the original target,
      * the original target is adapted to take the array type directly,
      * as if by a call to {@link #asType asType}.
      * <p>
@@ -570,21 +556,31 @@ public abstract class MethodHandle
      * What the target eventually returns is returned unchanged by the adapter.
      * <p>
      * (The array may also be a shared constant when {@code arrayLength} is zero.)
-     * @param arrayType usually {@code Object[]}, the type of the array argument which will collect the arguments
+     * <p>
+     * (<em>Note:</em> The {@code arrayType} is often identical to the last
+     * parameter type of the original target.
+     * It is an explicit argument for symmetry with {@code asSpreader}, and also
+     * to allow the target to use a simple {@code Object} as its last parameter type.)
+     * <p>
+     * In order to create a collecting adapter which is not restricted to a particular
+     * number of collected arguments, use {@link #asVarargsCollector asVarargsCollector} instead.
+     * @param arrayType often {@code Object[]}, the type of the array argument which will collect the arguments
      * @param arrayLength the number of arguments to collect into a new array argument
      * @return a new method handle which collects some trailing argument
      *         into an array, before calling the original method handle
      * @throws IllegalArgumentException if {@code arrayType} is not an array type
-               or {@code arrayType} is not assignable to this method handle's trailing parameter type
-     * @throws IllegalArgumentException if {@code arrayLength} is not
-     *         a legal array size
+     *         or {@code arrayType} is not assignable to this method handle's trailing parameter type,
+     *         or {@code arrayLength} is not a legal array size
      * @throws WrongMethodTypeException if the implied {@code asType} call fails
+     * @see #asSpreader
+     * @see #asVarargsCollector
      */
     public final MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
         Class<?> arrayElement = arrayType.getComponentType();
         if (arrayElement == null)  throw newIllegalArgumentException("not an array type");
         MethodType oldType = type();
         int nargs = oldType.parameterCount();
+        if (nargs == 0)  throw newIllegalArgumentException("no trailing argument");
         MethodType newType = oldType.dropParameterTypes(nargs-1, nargs);
         newType = newType.insertParameterTypes(nargs-1,
                     java.util.Collections.<Class<?>>nCopies(arrayLength, arrayElement));
@@ -592,8 +588,183 @@ public abstract class MethodHandle
     }
 
     /**
-     * Produce a method handle which binds the given argument
-     * to the current method handle as <i>target</i>.
+     * Make a <em>variable arity</em> adapter which is able to accept
+     * any number of trailing positional arguments and collect them
+     * into an array argument.
+     * <p>
+     * The type and behavior of the adapter will be the same as
+     * the type and behavior of the target, except that certain
+     * {@code invokeGeneric} and {@code asType} requests can lead to
+     * trailing positional arguments being collected into target's
+     * trailing parameter.
+     * Also, the last parameter type of the adapter will be
+     * {@code arrayType}, even if the target has a different
+     * last parameter type.
+     * <p>
+     * When called with {@link #invokeExact invokeExact}, the adapter invokes
+     * the target with no argument changes.
+     * (<em>Note:</em> This behavior is different from a
+     * {@linkplain #asCollector fixed arity collector},
+     * since it accepts a whole array of indeterminate length,
+     * rather than a fixed number of arguments.)
+     * <p>
+     * When called with {@link #invokeGeneric invokeGeneric}, if the caller
+     * type is the same as the adapter, the adapter invokes the target as with
+     * {@code invokeExact}.
+     * (This is the normal behavior for {@code invokeGeneric} when types match.)
+     * <p>
+     * Otherwise, if the caller and adapter arity are the same, and the
+     * trailing parameter type of the caller is a reference type identical to
+     * or assignable to the trailing parameter type of the adapter,
+     * the arguments and return values are converted pairwise,
+     * as if by {@link MethodHandles#convertArguments convertArguments}.
+     * (This is also normal behavior for {@code invokeGeneric} in such a case.)
+     * <p>
+     * Otherwise, the arities differ, or the adapter's trailing parameter
+     * type is not assignable from the corresponding caller type.
+     * In this case, the adapter replaces all trailing arguments from
+     * the original trailing argument position onward, by
+     * a new array of type {@code arrayType}, whose elements
+     * comprise (in order) the replaced arguments.
+     * <p>
+     * The caller type must provides as least enough arguments,
+     * and of the correct type, to satisfy the target's requirement for
+     * positional arguments before the trailing array argument.
+     * Thus, the caller must supply, at a minimum, {@code N-1} arguments,
+     * where {@code N} is the arity of the target.
+     * Also, there must exist conversions from the incoming arguments
+     * to the target's arguments.
+     * As with other uses of {@code invokeGeneric}, if these basic
+     * requirements are not fulfilled, a {@code WrongMethodTypeException}
+     * may be thrown.
+     * <p>
+     * In all cases, what the target eventually returns is returned unchanged by the adapter.
+     * <p>
+     * In the final case, it is exactly as if the target method handle were
+     * temporarily adapted with a {@linkplain #asCollector fixed arity collector}
+     * to the arity required by the caller type.
+     * (As with {@code asCollector}, if the array length is zero,
+     * a shared constant may be used instead of a new array.
+     * If the implied call to {@code asCollector} would throw
+     * an {@code IllegalArgumentException} or {@code WrongMethodTypeException},
+     * the call to the variable arity adapter must throw
+     * {@code WrongMethodTypeException}.)
+     * <p>
+     * The behavior of {@link #asType asType} is also specialized for
+     * variable arity adapters, to maintain the invariant that
+     * {@code invokeGeneric} is always equivalent to an {@code asType}
+     * call to adjust the target type, followed by {@code invokeExact}.
+     * Therefore, a variable arity adapter responds
+     * to an {@code asType} request by building a fixed arity collector,
+     * if and only if the adapter and requested type differ either
+     * in arity or trailing argument type.
+     * The resulting fixed arity collector has its type further adjusted
+     * (if necessary) to the requested type by pairwise conversion,
+     * as if by another application of {@code asType}.
+     * <p>
+     * When a method handle is obtained by executing an {@code ldc} instruction
+     * of a {@code CONSTANT_MethodHandle} constant, and the target method is marked
+     * as a variable arity method (with the modifier bit {@code 0x0080}),
+     * the method handle will accept multiple arities, as if the method handle
+     * constant were created by means of a call to {@code asVarargsCollector}.
+     * <p>
+     * In order to create a collecting adapter which collects a predetermined
+     * number of arguments, and whose type reflects this predetermined number,
+     * use {@link #asCollector asCollector} instead.
+     * <p>
+     * No method handle transformations produce new method handles with
+     * variable arity, unless they are documented as doing so.
+     * Therefore, besides {@code asVarargsCollector},
+     * all methods in {@code MethodHandle} and {@code MethodHandles}
+     * will return a method handle with fixed arity,
+     * except in the cases where they are specified to return their original
+     * operand (e.g., {@code asType} of the method handle's own type).
+     * <p>
+     * Calling {@code asVarargsCollector} on a method handle which is already
+     * of variable arity will produce a method handle with the same type and behavior.
+     * It may (or may not) return the original variable arity method handle.
+     * <p>
+     * Here is an example, of a list-making variable arity method handle:
+     * <blockquote><pre>
+MethodHandle asList = publicLookup()
+  .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
+  .asVarargsCollector(Object[].class);
+assertEquals("[]", asList.invokeGeneric().toString());
+assertEquals("[1]", asList.invokeGeneric(1).toString());
+assertEquals("[two, too]", asList.invokeGeneric("two", "too").toString());
+Object[] argv = { "three", "thee", "tee" };
+assertEquals("[three, thee, tee]", asList.invokeGeneric(argv).toString());
+List ls = (List) asList.invokeGeneric((Object)argv);
+assertEquals(1, ls.size());
+assertEquals("[three, thee, tee]", Arrays.toString((Object[])ls.get(0)));
+     * </pre></blockquote>
+     * <p style="font-size:smaller;">
+     * These rules are designed as a dynamically-typed variation
+     * of the Java rules for variable arity methods.
+     * In both cases, callers to a variable arity method or method handle
+     * can either pass zero or more positional arguments, or else pass
+     * pre-collected arrays of any length.  Users should be aware of the
+     * special role of the final argument, and of the effect of a
+     * type match on that final argument, which determines whether
+     * or not a single trailing argument is interpreted as a whole
+     * array or a single element of an array to be collected.
+     * Note that the dynamic type of the trailing argument has no
+     * effect on this decision, only a comparison between the static
+     * type signature of the call site and the type of the method handle.)
+     * <p style="font-size:smaller;">
+     * As a result of the previously stated rules, the variable arity behavior
+     * of a method handle may be suppressed, by binding it to the exact invoker
+     * of its own type, as follows:
+     * <blockquote><pre>
+MethodHandle vamh = publicLookup()
+  .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
+  .asVarargsCollector(Object[].class);
+MethodHandle invokeExact = publicLookup()
+  .findVirtual(MethodHandle.class, "invokeExact", vamh.type());
+MethodHandle mh = invokeExact.bindTo(vamh);
+assert(vamh.type().equals(mh.type()));
+assertEquals("[1, 2, 3]", vamh.invokeGeneric(1,2,3).toString());
+boolean failed = false;
+try { mh.invokeGeneric(1,2,3); }
+catch (WrongMethodTypeException ex) { failed = true; }
+assert(failed);
+     * </pre></blockquote>
+     * This transformation has no behavioral effect if the method handle is
+     * not of variable arity.
+     * @param arrayType often {@code Object[]}, the type of the array argument which will collect the arguments
+     * @return a new method handle which can collect any number of trailing arguments
+     *         into an array, before calling the original method handle
+     * @throws IllegalArgumentException if {@code arrayType} is not an array type
+     *         or {@code arrayType} is not assignable to this method handle's trailing parameter type
+     * @see #asCollector
+     */
+    public MethodHandle asVarargsCollector(Class<?> arrayType) {
+        Class<?> arrayElement = arrayType.getComponentType();
+        if (arrayElement == null)  throw newIllegalArgumentException("not an array type");
+        return MethodHandles.asVarargsCollector(this, arrayType);
+    }
+
+    /**
+     * Determine if this method handle
+     * supports {@linkplain #asVarargsCollector variable arity} calls.
+     * Such method handles arise from the following sources:
+     * <ul>
+     * <li>a call to {@linkplain #asVarargsCollector asVarargsCollector}
+     * <li>a call to a {@linkplain java.dyn.MethodHandles.Lookup lookup method}
+     *     which resolves to a variable arity Java method or constructor
+     * <li>an {@code ldc} instruction of a {@code CONSTANT_MethodHandle}
+     *     which resolves to a variable arity Java method or constructor
+     * </ul>
+     * @return true if this method handle accepts more than one arity of {@code invokeGeneric} calls
+     */
+    public boolean isVarargsCollector() {
+        return false;
+    }
+
+    /**
+     * Bind a value {@code x} to the first argument of a method handle, without invoking it.
+     * The new method handle adapts, as its <i>target</i>,
+     * to the current method handle.
      * The type of the bound handle will be
      * the same as the type of the target, except that a single leading
      * reference parameter will be omitted.
@@ -619,74 +790,22 @@ public abstract class MethodHandle
     }
 
     /**
-     * <em>PROVISIONAL API, WORK IN PROGRESS:</em>
-     * Create a new method handle with the same type as this one,
-     * but whose {@code asType} method invokes the given
-     * {@code typeHandler} on this method handle,
-     * instead of the standard {@code MethodHandles.convertArguments}.
-     * <p>
-     * The new method handle will have the same behavior as the
-     * old one when invoked by {@code invokeExact}.
-     * For {@code invokeGeneric} calls which exactly match
-     * the method type, the two method handles will also
-     * have the same behavior.
-     * For other {@code invokeGeneric} calls, the {@code typeHandler}
-     * will control the behavior of the new method handle.
-     * <p>
-     * Thus, a method handle with an {@code asType} handler can
-     * be configured to accept more than one arity of {@code invokeGeneric}
-     * call, and potentially every possible arity.
-     * It can also be configured to supply default values for
-     * optional arguments, when the caller does not specify them.
-     * <p>
-     * The given method handle must take two arguments and return
-     * one result.  The result it returns must be a method handle
-     * of exactly the requested type.  If the result returned by
-     * the target is null, a {@link NullPointerException} is thrown,
-     * else if the type of the target does not exactly match
-     * the requested type, a {@link WrongMethodTypeException} is thrown.
-     * <p>
-     * A method handle's type handler is not guaranteed to be called every
-     * time its {@code asType} or {@code invokeGeneric} method is called.
-     * If the implementation is faced is able to prove that an equivalent
-     * type handler call has already occurred (on the same two arguments),
-     * it may substitute the result of that previous invocation, without
-     * making a new invocation.  Thus, type handlers should not (in general)
-     * perform significant side effects.
-     * <p>
-     * Therefore, the type handler is invoked as if by this code:
+     * Returns a string representation of the method handle,
+     * starting with the string {@code "MethodHandle"} and
+     * ending with the string representation of the method handle's type.
+     * In other words, this method returns a string equal to the value of:
      * <blockquote><pre>
-     * MethodHandle target = this;      // original method handle
-     * MethodHandle adapter = ...;      // adapted method handle
-     * MethodType requestedType = ...;  // argument to asType()
-     * if (type().equals(requestedType))
-     *    return adapter;
-     * MethodHandle result = (MethodHandle)
-     *    typeHandler.invokeGeneric(target, requestedType);
-     * if (!result.type().equals(requestedType))
-     *    throw new WrongMethodTypeException();
-     * return result;
+     * "MethodHandle" + type().toString()
      * </pre></blockquote>
      * <p>
-     * For example, here is a list-making variable-arity method handle:
-     * <blockquote><pre>
-MethodHandle makeEmptyList = MethodHandles.constant(List.class, Arrays.asList());
-MethodHandle asList = lookup()
-  .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class));
-static MethodHandle collectingTypeHandler(MethodHandle base, MethodType newType) {
-  return asList.asCollector(Object[].class, newType.parameterCount()).asType(newType);
-}
-MethodHandle collectingTypeHandler = lookup()
-  .findStatic(lookup().lookupClass(), "collectingTypeHandler",
-     methodType(MethodHandle.class, MethodHandle.class, MethodType.class));
-MethodHandle makeAnyList = makeEmptyList.withTypeHandler(collectingTypeHandler);
-
-assertEquals("[]", makeAnyList.invokeGeneric().toString());
-assertEquals("[1]", makeAnyList.invokeGeneric(1).toString());
-assertEquals("[two, too]", makeAnyList.invokeGeneric("two", "too").toString());
-     * <pre><blockquote>
+     * Note:  Future releases of this API may add further information
+     * to the string representation.
+     * Therefore, the present syntax should not be parsed by applications.
+     *
+     * @return a string representation of the method handle
      */
-    public MethodHandle withTypeHandler(MethodHandle typeHandler) {
-        return MethodHandles.withTypeHandler(this, typeHandler);
+    @Override
+    public String toString() {
+        return MethodHandleImpl.getNameString(IMPL_TOKEN, this);
     }
 }

src/share/classes/java/dyn/MethodHandles.java

 /*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -135,7 +135,10 @@ public class MethodHandles {
      * <p>
      * In general, the conditions under which a method handle may be
      * created for a method {@code M} are exactly as restrictive as the conditions
-     * under which the lookup class could have compiled a call to {@code M}.
+     * under which the lookup class could have compiled a call to {@code M},
+     * or could have compiled an {@code ldc} instruction loading a
+     * {@code CONSTANT_MethodHandle} of M.
+     * The same point is true of fields and constructors.
      * <p>
      * In some cases, this access is obtained by the Java compiler by creating
      * an wrapper method to access a private method of another class
@@ -379,6 +382,10 @@ public class MethodHandles {
          * The method and all its argument types must be accessible to the lookup class.
          * If the method's class has not yet been initialized, that is done
          * immediately, before the method handle is returned.
+         * <p>
+         * The returned method handle will have
+         * {@linkplain MethodHandle#asVarargsCollector variable arity} if and only if
+         * the method's variable arity modifier bit ({@code 0x0080}) is set.
          * @param refc the class from which the method is accessed
          * @param name the name of the method
          * @param type the type of the method
@@ -403,6 +410,10 @@ public class MethodHandles {
          * implementation to enter.
          * (The dispatching action is identical with that performed by an
          * {@code invokevirtual} or {@code invokeinterface} instruction.)
+         * <p>
+         * The returned method handle will have
+         * {@linkplain MethodHandle#asVarargsCollector variable arity} if and only if
+         * the method's variable arity modifier bit ({@code 0x0080}) is set.
          * @param refc the class or interface from which the method is accessed
          * @param name the name of the method
          * @param type the type of the method, with the receiver argument omitted
@@ -427,6 +438,10 @@ public class MethodHandles {
          * <p>
          * Note:  The requested type must have a return type of {@code void}.
          * This is consistent with the JVM's treatment of constructor signatures.
+         * <p>
+         * The returned method handle will have
+         * {@linkplain MethodHandle#asVarargsCollector variable arity} if and only if
+         * the constructor's variable arity modifier bit ({@code 0x0080}) is set.
          * @param refc the class or interface from which the method is accessed
          * @param type the type of the method, with the receiver argument omitted, and a void return type
          * @return the desired method handle
@@ -438,7 +453,23 @@ public class MethodHandles {
             assert(ctor.isConstructor());
             checkAccess(refc, ctor);
             MethodHandle rawMH = MethodHandleImpl.findMethod(IMPL_TOKEN, ctor, false, lookupClassOrNull());
-            return MethodHandleImpl.makeAllocator(IMPL_TOKEN, rawMH);
+            MethodHandle allocMH = MethodHandleImpl.makeAllocator(IMPL_TOKEN, rawMH);
+            return fixVarargs(allocMH, rawMH);
+        }
+
+        /** Return a version of MH which matches matchMH w.r.t. isVarargsCollector. */
+        private static MethodHandle fixVarargs(MethodHandle mh, MethodHandle matchMH) {
+            boolean va1 = mh.isVarargsCollector();
+            boolean va2 = matchMH.isVarargsCollector();
+            if (va1 == va2) {
+                return mh;
+            } else if (va2) {
+                MethodType type = mh.type();
+                int arity = type.parameterCount();
+                return mh.asVarargsCollector(type.parameterType(arity-1));
+            } else {
+                throw new InternalError("already varargs, but template is not: "+mh);
+            }
         }
 
         /**
@@ -458,6 +489,10 @@ public class MethodHandles {
          * If the explicitly specified caller class is not identical with the
          * lookup class, or if this lookup object does not have private access
          * privileges, the access fails.
+         * <p>
+         * The returned method handle will have
+         * {@linkplain MethodHandle#asVarargsCollector variable arity} if and only if
+         * the method's variable arity modifier bit ({@code 0x0080}) is set.
          * @param refc the class or interface from which the method is accessed
          * @param name the name of the method (which must not be "&lt;init&gt;")
          * @param type the type of the method, with the receiver argument omitted
@@ -547,13 +582,26 @@ public class MethodHandles {
          * so that every call to the method handle will invoke the
          * requested method on the given receiver.
          * <p>
-         * This is equivalent to the following expression:
-         * <code>
-         * {@link #insertArguments insertArguments}({@link #findVirtual findVirtual}(defc, name, type), receiver)
-         * </code>
+         * The returned method handle will have
+         * {@linkplain MethodHandle#asVarargsCollector variable arity} if and only if
+         * the method's variable arity modifier bit ({@code 0x0080}) is set
+         * <em>and</em> the trailing array argument is not the only argument.
+         * (If the trailing array argument is the only argument,
+         * the given receiver value will be bound to it.)
+         * <p>
+         * This is equivalent to the following code:
+         * <blockquote><pre>
+MethodHandle mh0 = {@link #findVirtual findVirtual}(defc, name, type);
+MethodHandle mh1 = mh0.{@link MethodHandle#bindTo bindTo}(receiver);
+MethodType mt1 = mh1.type();
+if (mh0.isVarargsCollector() && mt1.parameterCount() > 0) {
+  mh1 = mh1.asVarargsCollector(mt1.parameterType(mt1.parameterCount()-1));
+return mh1;
+         * </pre></blockquote>
          * where {@code defc} is either {@code receiver.getClass()} or a super
          * type of that class, in which the requested method is accessible
          * to the lookup class.
+         * (Note that {@code bindTo} does not preserve variable arity.)
          * @param receiver the object from which the method is accessed
          * @param name the name of the method
          * @param type the type of the method, with the receiver argument omitted
@@ -568,7 +616,9 @@ public class MethodHandles {
             MethodHandle bmh = MethodHandleImpl.bindReceiver(IMPL_TOKEN, dmh, receiver);
             if (bmh == null)
                 throw newNoAccessException(method, lookupClass());
-            return bmh;
+            if (dmh.type().parameterCount() == 0)
+                return dmh;  // bound the trailing parameter; no varargs possible
+            return fixVarargs(bmh, dmh);
         }
 
         /**
@@ -581,6 +631,10 @@ public class MethodHandles {
          * If the method's {@code accessible} flag is not set,
          * access checking is performed immediately on behalf of the lookup class.
          * If <i>m</i> is not public, do not share the resulting handle with untrusted parties.
+         * <p>
+         * The returned method handle will have
+         * {@linkplain MethodHandle#asVarargsCollector variable arity} if and only if
+         * the method's variable arity modifier bit ({@code 0x0080}) is set.
          * @param m the reflected method
          * @return a method handle which can invoke the reflected method
          * @exception NoAccessException if access checking fails
@@ -603,6 +657,10 @@ public class MethodHandles {
          * If the method's {@code accessible} flag is not set,
          * access checking is performed immediately on behalf of the lookup class,
          * as if {@code invokespecial} instruction were being linked.
+         * <p>
+         * The returned method handle will have
+         * {@linkplain MethodHandle#asVarargsCollector variable arity} if and only if
+         * the method's variable arity modifier bit ({@code 0x0080}) is set.
          * @param m the reflected method
          * @param specialCaller the class nominally calling the method
          * @return a method handle which can invoke the reflected method
@@ -628,6 +686,10 @@ public class MethodHandles {
          * <p>
          * If the constructor's {@code accessible} flag is not set,
          * access checking is performed immediately on behalf of the lookup class.
+         * <p>
+         * The returned method handle will have
+         * {@linkplain MethodHandle#asVarargsCollector variable arity} if and only if
+         * the constructor's variable arity modifier bit ({@code 0x0080}) is set.
          * @param c the reflected constructor
          * @return a method handle which can invoke the reflected constructor
          * @exception NoAccessException if access checking fails
@@ -637,7 +699,8 @@ public class MethodHandles {
             assert(ctor.isConstructor());
             if (!c.isAccessible())  checkAccess(c.getDeclaringClass(), ctor);
             MethodHandle rawCtor = MethodHandleImpl.findMethod(IMPL_TOKEN, ctor, false, lookupClassOrNull());
-            return MethodHandleImpl.makeAllocator(IMPL_TOKEN, rawCtor);
+            MethodHandle allocator = MethodHandleImpl.makeAllocator(IMPL_TOKEN, rawCtor);
+            return fixVarargs(allocator, rawCtor);
         }
 
         /**
@@ -785,7 +848,8 @@ public class MethodHandles {
             MethodType rawType = mh.type();
             if (rawType.parameterType(0) == caller)  return mh;
             MethodType narrowType = rawType.changeParameterType(0, caller);
-            return MethodHandleImpl.convertArguments(IMPL_TOKEN, mh, narrowType, rawType, null);
+            MethodHandle narrowMH = MethodHandleImpl.convertArguments(IMPL_TOKEN, mh, narrowType, rawType, null);
+            return fixVarargs(narrowMH, mh);
         }
 
         MethodHandle makeAccessor(Class<?> refc, String name, Class<?> type,
@@ -909,22 +973,21 @@ public class MethodHandles {
      * <p>
      * This method is equivalent to the following code (though it may be more efficient):
      * <p><blockquote><pre>
-     * MethodHandle invoker = lookup().findVirtual(MethodHandle.class, "invokeGeneric", type);
-     * MethodType vaType = MethodType.genericMethodType(objectArgCount, true);
-     * vaType = vaType.insertParameterType(0, MethodHandle.class);
-     * int spreadArgCount = type.parameterCount - objectArgCount;
-     * invoker = invoker.asSpreader(Object.class, spreadArgCount);
-     * return invoker.asType(vaType);
+MethodHandle invoker = publicLookup()
+  .findVirtual(MethodHandle.class, "invokeGeneric", type)
+int spreadArgCount = type.parameterCount - objectArgCount;
+invoker = invoker.asSpreader(Object[].class, spreadArgCount);
+return invoker;
      * </pre></blockquote>
      * @param type the desired target type
      * @param objectArgCount number of fixed (non-varargs) {@code Object} arguments
      * @return a method handle suitable for invoking any method handle of the given type
      */
     static public
-    MethodHandle varargsInvoker(MethodType type, int objectArgCount) {
+    MethodHandle spreadInvoker(MethodType type, int objectArgCount) {
         if (objectArgCount < 0 || objectArgCount > type.parameterCount())
             throw new IllegalArgumentException("bad argument count "+objectArgCount);
-        return invokers(type).varargsInvoker(objectArgCount);
+        return invokers(type).spreadInvoker(objectArgCount);
     }
 
     /**
@@ -1826,7 +1889,10 @@ System.out.println((int) f0.invokeExact("x", "y")); // 2
      * the given {@code target} on the incoming arguments,
      * and returning or throwing whatever the {@code target}
      * returns or throws.  The invocation will be as if by
-     * {@code target.invokeExact}.
+     * {@code target.invokeGeneric}.
+     * The target's type will be checked before the SAM
+     * instance is created, as if by a call to {@code asType},
+     * which may result in a {@code WrongMethodTypeException}.
      * <p>
      * The method handle may throw an <em>undeclared exception</em>,
      * which means any checked exception (or other checked throwable)
@@ -1874,15 +1940,17 @@ System.out.println((int) f0.invokeExact("x", "y")); // 2
      * {@link java.dyn.MethodHandles.AsInstanceObject AsInstanceObject}
      * in the adapters, so that generic code can extract the underlying
      * method handle without knowing where the SAM adapter came from.
+     * <p>
+     * Future versions of this API may accept additional types,
+     * such as abstract classes with single abstract methods.
      * @param target the method handle to invoke from the wrapper
      * @param samType the desired type of the wrapper, a SAM type
      * @return a correctly-typed wrapper for the given {@code target}
-     * @throws IllegalArgumentException if the {@code target} throws
-     *         an undeclared exception
+     * @throws IllegalArgumentException if the {@code samType} is not a
+     *         valid argument to this method
+     * @throws WrongMethodTypeException if the {@code target} cannot
+     *         be converted to the type required by the SAM type
      */
-    // ISSUE: Should we delegate equals/hashCode to the targets?
-    // Not useful unless there is a stable equals/hashCode behavior
-    // for MethodHandle, but there isn't.
     public static
     <T> T asInstance(final MethodHandle target, final Class<T> samType) {
         // POC implementation only; violates the above contract several ways
@@ -1890,8 +1958,9 @@ System.out.println((int) f0.invokeExact("x", "y")); // 2
         if (sam == null)
             throw new IllegalArgumentException("not a SAM type: "+samType.getName());
         MethodType samMT = MethodType.methodType(sam.getReturnType(), sam.getParameterTypes());
-        if (!samMT.equals(target.type()))
-            throw new IllegalArgumentException("wrong method type: "+target+" should match "+sam);
+        MethodHandle checkTarget = target.asType(samMT);  // make throw WMT
+        checkTarget = checkTarget.asType(checkTarget.type().changeReturnType(Object.class));
+        final MethodHandle vaTarget = checkTarget.asSpreader(Object[].class, samMT.parameterCount());
         return samType.cast(Proxy.newProxyInstance(
                 samType.getClassLoader(),
                 new Class[]{ samType, AsInstanceObject.class },
@@ -1905,7 +1974,7 @@ System.out.println((int) f0.invokeExact("x", "y")); // 2
                         if (method.getDeclaringClass() == AsInstanceObject.class)
                             return getArg(method.getName());
                         if (method.equals(sam))
-                            return target.invokeVarargs(args);
+                            return vaTarget.invokeExact(args);
                         if (isObjectMethod(method))
                             return callObjectMethod(this, method, args);
                         throw new InternalError();
@@ -1991,7 +2060,7 @@ System.out.println((int) f0.invokeExact("x", "y")); // 2
     }
 
     /*non-public*/
-    static MethodHandle withTypeHandler(MethodHandle target, MethodHandle typeHandler) {
-        return MethodHandleImpl.withTypeHandler(IMPL_TOKEN, target, typeHandler);
+    static MethodHandle asVarargsCollector(MethodHandle target, Class<?> arrayType) {
+        return MethodHandleImpl.asVarargsCollector(IMPL_TOKEN, target, arrayType);
     }
 }

src/share/classes/java/dyn/package-info.java

 /*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -166,13 +166,13 @@
  * normal accesses are legal.
  * <p>
  * A constant may refer to a method or constructor with the {@code varargs}
- * bit (hexadecimal {@code 80}) set in its modifier bitmask.
- * The method handle constant produced for such a method behaves the same
+ * bit (hexadecimal {@code 0x0080}) set in its modifier bitmask.
+ * The method handle constant produced for such a method behaves as if
+ * it were created by {@link java.dyn.MethodHandle#asVarargsCollector asVarargsCollector}.
+ * In other words, the constant method handle will exhibit variable arity,
+ * when invoked via {@code invokeGeneric}.
+ * On the other hand, its behavior with respect to {@code invokeExact} will be the same
  * as if the {@code varargs} bit were not set.
- * The argument-collecting behavior of {@code varargs} can be emulated by
- * adapting the method handle constant with
- * {@link java.dyn.MethodHandle#asCollector asCollector}.
- * There is no provision for doing this automatically.
  * <p>
  * Although the {@code CONSTANT_MethodHandle} and {@code CONSTANT_MethodType} constant types
  * resolve class names, they do not force class initialization.
@@ -369,21 +369,40 @@
  * the instruction's bootstrap method will be invoked on three arguments,
  * conveying the instruction's caller class, name, and method type.
  * If the {@code invokedynamic} instruction specifies one or more static arguments,
- * a fourth argument will be passed to the bootstrap argument,
- * either an {@code Object} reference to the sole extra argument (if there is one)
- * or an {@code Object} array of references to all the arguments (if there are two or more),
- * as if the bootstrap method is a variable-arity method.
+ * those values will be passed as additional arguments to the method handle.
+ * (Note that because there is a limit of 255 arguments to any method,
+ * at most 252 extra arguments can be supplied.)
+ * The bootstrap method will be invoked as if by either {@code invokeGeneric}
+ * or {@code invokeWithArguments}.  (There is no way to tell the difference.)
+ * If the bootstrap method is a variable arity method (its modifier bit {@code 0x0080} is set),
+ * then some or all of the arguments specified here may be collected into a trailing array parameter.
+ * (This is not a special rule, but rather a useful consequence of the interaction
+ * between {@code CONSTANT_MethodHandle} constants, the modifier bit for variable arity methods,
+ * and the {@code java.dyn.MethodHandle#asVarargsCollector asVarargsCollector} transformation.)
+ * <p>
+ * Given these rules, here are examples of legal bootstrap method declarations,
+ * given various numbers {@code N} of extra arguments.
+ * The first rows (marked {@code *}) will work for any number of extra arguments.
  * <code>
  * <table border=1 cellpadding=5 summary="Static argument types">
  * <tr><th>N</th><th>sample bootstrap method</th></tr>
+ * <tr><td>*</td><td><code>CallSite bootstrap(Lookup caller, String name, MethodType type, Object... args)</code></td></tr>
+ * <tr><td>*</td><td><code>CallSite bootstrap(Object... args)</code></td></tr>
+ * <tr><td>*</td><td><code>CallSite bootstrap(Object caller, Object... nameAndTypeWithArgs)</code></td></tr>
  * <tr><td>0</td><td><code>CallSite bootstrap(Lookup caller, String name, MethodType type)</code></td></tr>
+ * <tr><td>0</td><td><code>CallSite bootstrap(Lookup caller, Object... nameAndType)</code></td></tr>
  * <tr><td>1</td><td><code>CallSite bootstrap(Lookup caller, String name, MethodType type, Object arg)</code></td></tr>
  * <tr><td>2</td><td><code>CallSite bootstrap(Lookup caller, String name, MethodType type, Object... args)</code></td></tr>
+ * <tr><td>2</td><td><code>CallSite bootstrap(Lookup caller, String name, MethodType type, String... args)</code></td></tr>
+ * <tr><td>2</td><td><code>CallSite bootstrap(Lookup caller, String name, MethodType type, String x, int y)</code></td></tr>
  * </table>
  * </code>
+ * The last example assumes that the extra arguments are of type
+ * {@code CONSTANT_String} and {@code CONSTANT_Integer}, respectively.
+ * The second-to-last example assumes that all extra arguments are of type
+ * {@code CONSTANT_String}.
+ * The other examples work with all types of extra arguments.
  * <p>
- * The argument and return types listed here are used by the {@code invokeGeneric}
- * call to the bootstrap method.
  * As noted above, the actual method type of the bootstrap method can vary.
  * For example, the fourth argument could be {@code MethodHandle},
  * if that is the type of the corresponding constant in
@@ -391,14 +410,8 @@
  * In that case, the {@code invokeGeneric} call will pass the extra method handle
  * constant as an {@code Object}, but the type matching machinery of {@code invokeGeneric}
  * will cast the reference back to {@code MethodHandle} before invoking the bootstrap method.
- * (If a string constant were passed instead, by badly generated code, that cast would then fail.)
- * <p>
- * If the fourth argument is an array, the array element type must be {@code Object},
- * since object arrays (as produced by the JVM at this point) cannot be converted
- * to other array types.
- * <p>
- * If an array is provided, it will appear to be freshly allocated.
- * That is, the same array will not appear to two bootstrap method calls.
+ * (If a string constant were passed instead, by badly generated code, that cast would then fail,
+ * resulting in an {@code InvokeDynamicBootstrapError}.)
  * <p>
  * Extra bootstrap method arguments are intended to allow language implementors
  * to safely and compactly encode metadata.
@@ -406,24 +419,6 @@
  * since each call site could be given its own unique bootstrap method.
  * Such a practice is likely to produce large class files and constant pools.
  *
- * <p style="font-size:smaller;">
- * <em>PROVISIONAL API, WORK IN PROGRESS:</em>
- * (Usage Note: There is no mechanism for specifying five or more positional arguments to the bootstrap method.
- * If there are two or more arguments, the Java code of the bootstrap method is required to extract them from
- * a varargs-style object array.
- * This design uses varargs because it anticipates some use cases where bootstrap arguments
- * contribute components of variable-length structures, such as virtual function tables
- * or interpreter token streams.
- * Such parameters would be awkward or impossible to manage if represented
- * as normal positional method arguments,
- * since there would need to be one Java method per length.
- * On balance, leaving out the varargs feature would cause more trouble to users than keeping it.
- * Also, this design allows bootstrap methods to be called in a limited JVM stack depth.
- * At both the user and JVM level, the difference between varargs and non-varargs
- * calling sequences can easily be bridged via the
- * {@link java.dyn.MethodHandle#asSpreader asSpreader}
- * and {@link java.dyn.MethodHandle#asSpreader asCollector} methods.)
- *
  * <h2><a name="structs"></a>Structure Summary</h2>
  * <blockquote><pre>// summary of constant and attribute structures
 struct CONSTANT_MethodHandle_info {

src/share/classes/sun/dyn/AdapterMethodHandle.java

 /*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -478,37 +478,60 @@ public class AdapterMethodHandle extends BoundMethodHandle {
         return new AdapterMethodHandle(target, newType, makeConv(raw ? OP_RETYPE_RAW : OP_RETYPE_ONLY));
     }
 
-    static MethodHandle makeTypeHandler(Access token,
-                MethodHandle target, MethodHandle typeHandler) {
+    static MethodHandle makeVarargsCollector(Access token,
+                MethodHandle target, Class<?> arrayType) {
         Access.check(token);
-        return new WithTypeHandler(target, typeHandler);
+        return new AsVarargsCollector(target, arrayType);
     }
 
-    static class WithTypeHandler extends AdapterMethodHandle {
-        final MethodHandle target, typeHandler;
-        WithTypeHandler(MethodHandle target, MethodHandle typeHandler) {
+    static class AsVarargsCollector extends AdapterMethodHandle {
+        final MethodHandle target;
+        final Class<?> arrayType;
+        MethodHandle cache;
+
+        AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
             super(target, target.type(), makeConv(OP_RETYPE_ONLY));
             this.target = target;
-            this.typeHandler = typeHandler.asType(TYPE_HANDLER_TYPE);
+            this.arrayType = arrayType;
+            this.cache = target.asCollector(arrayType, 0);
         }
 
+        @Override
+        public boolean isVarargsCollector() {
+            return true;
+        }
+
+        @Override
         public MethodHandle asType(MethodType newType) {
-            if (this.type() == newType)
-                return this;
+            MethodType type = this.type();
+            int collectArg = type.parameterCount() - 1;
+            int newArity = newType.parameterCount();
+            if (newArity == collectArg+1 &&
+                type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
+                // if arity and trailing parameter are compatible, do normal thing
+                return super.asType(newType);
+            }
+            // check cache
+            if (cache.type().parameterCount() == newArity)
+                return cache.asType(newType);
+            // build and cache a collector
+            int arrayLength = newArity - collectArg;
+            MethodHandle collector;
             try {
-                MethodHandle retyped = (MethodHandle) typeHandler.invokeExact(target, newType);
-                // Contract:  Must return the desired type, or throw WMT
-                if (retyped.type() != newType)
-                    throw new WrongMethodTypeException(retyped.toString());
-                return retyped;
-            } catch (Throwable ex) {
-                if (ex instanceof Error)  throw (Error)ex;
-                if (ex instanceof RuntimeException)  throw (RuntimeException)ex;
-                throw new RuntimeException(ex);
+                collector = target.asCollector(arrayType, arrayLength);
+            } catch (IllegalArgumentException ex) {
+                throw new WrongMethodTypeException("cannot build collector");
             }
+            cache = collector;
+            return collector.asType(newType);
+        }
+
+        public MethodHandle asVarargsCollector(Class<?> arrayType) {
+            MethodType type = this.type();
+            if (type.parameterType(type.parameterCount()-1) == arrayType)
+                return this;
+            return super.asVarargsCollector(arrayType);
         }
-        private static final MethodType TYPE_HANDLER_TYPE
-            = MethodType.methodType(MethodHandle.class, MethodHandle.class, MethodType.class);
     }
 
     /** Can a checkcast adapter validly convert the target to newType?

src/share/classes/sun/dyn/CallSiteImpl.java

@@ -37,17 +37,17 @@ public class CallSiteImpl {
     static CallSite makeSite(MethodHandle bootstrapMethod,
                              // Callee information:
                              String name, MethodType type,
-                             // Call-site attributes, if any:
+                             // Extra arguments for BSM, if any:
                              Object info,
                              // Caller information:
                              MemberName callerMethod, int callerBCI) {
         Class<?> callerClass = callerMethod.getDeclaringClass();
         Object caller;
-        if (bootstrapMethod.type().parameterType(0) == Class.class)
+        if (bootstrapMethod.type().parameterType(0) == Class.class && TRANSITIONAL_BEFORE_PFD)
             caller = callerClass;  // remove for PFD
         else
             caller = MethodHandleImpl.IMPL_LOOKUP.in(callerClass);
-        if (bootstrapMethod == null) {
+        if (bootstrapMethod == null && TRANSITIONAL_BEFORE_PFD) {
             // If there is no bootstrap method, throw IncompatibleClassChangeError.
             // This is a valid generic error type for resolution (JLS 12.3.3).
             throw new IncompatibleClassChangeError
@@ -56,30 +56,35 @@ public class CallSiteImpl {
         CallSite site;
         try {
             Object binding;
+            info = maybeReBox(info);
             if (info == null) {
-                if (false)  // switch when invokeGeneric works
-                    binding = bootstrapMethod.invokeGeneric(caller, name, type);
-                else
-                    binding = bootstrapMethod.invokeVarargs(new Object[]{ caller, name, type });
+                binding = bootstrapMethod.invokeGeneric(caller, name, type);
+            } else if (!info.getClass().isArray()) {
+                binding = bootstrapMethod.invokeGeneric(caller, name, type, info);
             } else {
-                info = maybeReBox(info);
-                if (false)  // switch when invokeGeneric works
-                    binding = bootstrapMethod.invokeGeneric(caller, name, type, info);
+                Object[] argv = (Object[]) info;
+                if (3 + argv.length > 255)
+                    new InvokeDynamicBootstrapError("too many bootstrap method arguments");
+                MethodType bsmType = bootstrapMethod.type();
+                if (bsmType.parameterCount() == 4 && bsmType.parameterType(3) == Object[].class)
+                    binding = bootstrapMethod.invokeGeneric(caller, name, type, argv);
                 else
-                    binding = bootstrapMethod.invokeVarargs(new Object[]{ caller, name, type, info });
+                    binding = MethodHandles.spreadInvoker(bsmType, 3)
+                        .invokeGeneric(bootstrapMethod, caller, name, type, argv);
             }
             //System.out.println("BSM for "+name+type+" => "+binding);
             if (binding instanceof CallSite) {
                 site = (CallSite) binding;
-            } else if (binding instanceof MethodHandle) {
+            } else if (binding instanceof MethodHandle && TRANSITIONAL_BEFORE_PFD) {
                 // Transitional!
                 MethodHandle target = (MethodHandle) binding;
                 site = new ConstantCallSite(target);
             } else {
-                throw new ClassCastException("bootstrap method failed to produce a MethodHandle or CallSite");
+                throw new ClassCastException("bootstrap method failed to produce a CallSite");
             }
-            PRIVATE_INITIALIZE_CALL_SITE.invokeExact(site, name, type,
-                                                     callerMethod, callerBCI);
+            if (TRANSITIONAL_BEFORE_PFD)
+                PRIVATE_INITIALIZE_CALL_SITE.invokeExact(site, name, type,
+                                                         callerMethod, callerBCI);
             assert(site.getTarget() != null);
             assert(site.getTarget().type().equals(type));
         } catch (Throwable ex) {
@@ -93,6 +98,8 @@ public class CallSiteImpl {
         return site;
     }
 
+    private static boolean TRANSITIONAL_BEFORE_PFD = true;  // FIXME: remove for PFD
+
     private static Object maybeReBox(Object x) {
         if (x instanceof Integer) {
             int xi = (int) x;
@@ -117,6 +124,7 @@ public class CallSiteImpl {
     static {
         try {
             PRIVATE_INITIALIZE_CALL_SITE =
+            !TRANSITIONAL_BEFORE_PFD ? null :
             MethodHandleImpl.IMPL_LOOKUP.findVirtual(CallSite.class, "initializeFromJVM",
                 MethodType.methodType(void.class,
                                       String.class, MethodType.class,

src/share/classes/sun/dyn/InvokeGeneric.java

 /*
- * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -108,7 +108,7 @@ class InvokeGeneric {
      */
     private MethodHandle dispatch(MethodType callerType, MethodHandle target) {
         MethodType targetType = target.type();
-        if (USE_AS_TYPE_PATH || target instanceof AdapterMethodHandle.WithTypeHandler) {
+        if (USE_AS_TYPE_PATH || target.isVarargsCollector()) {
             MethodHandle newTarget = target.asType(callerType);
             targetType = callerType;
             Invokers invokers = MethodTypeImpl.invokers(Access.TOKEN, targetType);

src/share/classes/sun/dyn/Invokers.java

 /*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,7 +47,7 @@ public class Invokers {
     private /*lazy*/ MethodHandle genericInvoker;
 
     // generic (untyped) invoker for the outgoing call; accepts a single Object[]
-    private final /*lazy*/ MethodHandle[] varargsInvokers;
+    private final /*lazy*/ MethodHandle[] spreadInvokers;
 
     // invoker for an unbound callsite
     private /*lazy*/ MethodHandle uninitializedCallSite;
@@ -55,10 +55,9 @@ public class Invokers {
     /** Compute and cache information common to all collecting adapters
      *  that implement members of the erasure-family of the given erased type.
      */
-    public Invokers(Access token, MethodType targetType) {
-        Access.check(token);
+    /*non-public*/ Invokers(MethodType targetType) {
         this.targetType = targetType;
-        this.varargsInvokers = new MethodHandle[targetType.parameterCount()+1];
+        this.spreadInvokers = new MethodHandle[targetType.parameterCount()+1];
     }
 
     public static MethodType invokerType(MethodType targetType) {
@@ -69,7 +68,7 @@ public class Invokers {
         MethodHandle invoker = exactInvoker;
         if (invoker != null)  return invoker;
         try {
-            invoker = MethodHandleImpl.IMPL_LOOKUP.findVirtual(MethodHandle.class, "invoke", targetType);
+            invoker = MethodHandleImpl.IMPL_LOOKUP.findVirtual(MethodHandle.class, "invokeExact", targetType);
         } catch (NoAccessException ex) {
             throw new InternalError("JVM cannot find invoker for "+targetType);
         }
@@ -101,13 +100,13 @@ public class Invokers {
         return invoker;
     }
 
-    public MethodHandle varargsInvoker(int objectArgCount) {
-        MethodHandle vaInvoker = varargsInvokers[objectArgCount];
+    public MethodHandle spreadInvoker(int objectArgCount) {
+        MethodHandle vaInvoker = spreadInvokers[objectArgCount];
         if (vaInvoker != null)  return vaInvoker;
         MethodHandle gInvoker = genericInvoker();
         MethodType vaType = MethodType.genericMethodType(objectArgCount, true);
         vaInvoker = MethodHandles.spreadArguments(gInvoker, invokerType(vaType));
-        varargsInvokers[objectArgCount] = vaInvoker;
+        spreadInvokers[objectArgCount] = vaInvoker;
         return vaInvoker;
     }
 
@@ -118,7 +117,7 @@ public class Invokers {
         if (invoker != null)  return invoker;
         if (targetType.parameterCount() > 0) {
             MethodType type0 = targetType.dropParameterTypes(0, targetType.parameterCount());
-            Invokers invokers0 = MethodTypeImpl.invokers(Access.TOKEN, type0);
+            Invokers invokers0 = MethodTypeImpl.invokers(type0);
             invoker = MethodHandles.dropArguments(invokers0.uninitializedCallSite(),
                                                   0, targetType.parameterList());
             assert(invoker.type().equals(targetType));

src/share/classes/sun/dyn/MethodHandleImpl.java

 /*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -184,7 +184,10 @@ public abstract class MethodHandleImpl {
         if (!mh.isValid())
             throw newNoAccessException(method, lookupClass);
         assert(mh.type() == mtype);
-        return mh;
+        if (!method.isVarargs())
+            return mh;
+        else
+            return mh.asVarargsCollector(mtype.parameterType(mtype.parameterCount()-1));
     }
 
     public static
@@ -1263,8 +1266,8 @@ public abstract class MethodHandleImpl {
         return MethodHandleNatives.getBootstrap(callerClass);
     }
 
-    public static MethodHandle withTypeHandler(Access token, MethodHandle target, MethodHandle typeHandler) {
+    public static MethodHandle asVarargsCollector(Access token, MethodHandle target, Class<?> arrayType) {
         Access.check(token);
-        return AdapterMethodHandle.makeTypeHandler(token, target, typeHandler);
+        return AdapterMethodHandle.makeVarargsCollector(token, target, arrayType);
     }
 }

src/share/classes/sun/dyn/MethodTypeImpl.java

 /*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -498,9 +498,12 @@ public class MethodTypeImpl {
 
     public static Invokers invokers(Access token, MethodType type) {
         Access.check(token);
+        return invokers(type);
+    }
+    /*non-public*/ static Invokers invokers(MethodType type) {
         Invokers inv = METHOD_TYPE_FRIEND.getInvokers(type);
         if (inv != null)  return inv;
-        inv = new Invokers(token, type);
+        inv = new Invokers(type);
         METHOD_TYPE_FRIEND.setInvokers(type, inv);
         return inv;
     }

test/java/dyn/InvokeDynamicPrintArgs.java

@@ -23,15 +23,19 @@
 
 /* @test
  * @summary smoke test for invokedynamic instructions
- * @library indify
+ * @build indify.Indify
  * @compile InvokeDynamicPrintArgs.java
  * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+EnableInvokeDynamic
  *      indify.Indify
  *      --verify-specifier-count=3 --transitionalJSR292=false
  *      --expand-properties --classpath ${test.classes}
- *      --java InvokeDynamicPrintArgs --check-output
+ *      --java test.java.dyn.InvokeDynamicPrintArgs --check-output
  */
 
+package test.java.dyn;
+
+import org.junit.Test;
+
 import java.util.*;
 import java.io.*;
 
@@ -53,6 +57,20 @@ public class InvokeDynamicPrintArgs {
         closeBuf();
     }
 
+    @Test
+    public void testInvokeDynamicPrintArgs() throws IOException {
+        System.err.println(System.getProperties());
+        String testClassPath = System.getProperty("build.test.classes.dir");
+        if (testClassPath == null)  throw new RuntimeException();
+        String[] args = new String[]{
+            "--verify-specifier-count=3", "--transitionalJSR292=false",
+            "--expand-properties", "--classpath", testClassPath,
+            "--java", "test.java.dyn.InvokeDynamicPrintArgs", "--check-output"
+        };
+        System.err.println("Indify: "+Arrays.toString(args));
+        indify.Indify.main(args);
+    }
+
     private static PrintStream oldOut;
     private static ByteArrayOutputStream buf;
     private static void openBuf() {
@@ -79,11 +97,11 @@ public class InvokeDynamicPrintArgs {
     }
     private static final String[] EXPECT_OUTPUT = {
         "Printing some argument lists, starting with a empty one:",
-        "[InvokeDynamicPrintArgs, nothing, ()void][]",
-        "[InvokeDynamicPrintArgs, bar, (java.lang.String,int)void, class java.lang.Void, void type!, 1, 234.5, 67.5, 89][bar arg, 1]",
-        "[InvokeDynamicPrintArgs, bar2, (java.lang.String,int)void, class java.lang.Void, void type!, 1, 234.5, 67.5, 89][bar2 arg, 222]",
-        "[InvokeDynamicPrintArgs, baz, (java.lang.String,int,double)void, 1234.5][baz arg, 2, 3.14]",
-        "[InvokeDynamicPrintArgs, foo, (java.lang.String)void][foo arg]",
+        "[test.java.dyn.InvokeDynamicPrintArgs, nothing, ()void][]",
+        "[test.java.dyn.InvokeDynamicPrintArgs, bar, (String,int)void, class java.lang.Void, void type!, 1, 234.5, 67.5, 89][bar arg, 1]",
+        "[test.java.dyn.InvokeDynamicPrintArgs, bar2, (String,int)void, class java.lang.Void, void type!, 1, 234.5, 67.5, 89][bar2 arg, 222]",
+        "[test.java.dyn.InvokeDynamicPrintArgs, baz, (String,int,double)void, 1234.5][baz arg, 2, 3.14]",
+        "[test.java.dyn.InvokeDynamicPrintArgs, foo, (String)void][foo arg]",
         "Done printing argument lists."
     };
 
@@ -110,18 +128,15 @@ public class InvokeDynamicPrintArgs {
         return lookup().findStatic(lookup().lookupClass(), "bsm", MT_bsm());
     }
 
-    private static CallSite bsm2(Lookup caller, String name, MethodType type, Object arg) throws ReflectiveOperationException {
+    private static CallSite bsm2(Lookup caller, String name, MethodType type, Object... arg) throws ReflectiveOperationException {
         // ignore caller and name, but match the type:
         List<Object> bsmInfo = new ArrayList<>(Arrays.asList(caller, name, type));
-        if (arg instanceof Object[])
-            bsmInfo.addAll(Arrays.asList((Object[])arg));
-        else
-            bsmInfo.add(arg);
+        bsmInfo.addAll(Arrays.asList((Object[])arg));
         return new ConstantCallSite(MH_printArgs().bindTo(bsmInfo).asCollector(Object[].class, type.parameterCount()).asType(type));
     }
     private static MethodType MT_bsm2() {
         shouldNotCallThis();
-        return methodType(CallSite.class, Lookup.class, String.class, MethodType.class, Object.class);
+        return methodType(CallSite.class, Lookup.class, String.class, MethodType.class, Object[].class);
     }
     private static MethodHandle MH_bsm2() throws ReflectiveOperationException {
         shouldNotCallThis();

test/java/dyn/JavaDocExamplesTest.java

 /*
- * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -142,37 +142,80 @@ assertEquals("XY", (String) f2.invokeExact("x", "y")); // XY
         Assert.assertEquals(exp, act);
     }
 
-static MethodHandle asList;
-    @Test public void testWithTypeHandler() throws Throwable {
+    @Test public void testMethodHandlesSummary() throws Throwable {
         {{
 {} /// JAVADOC
-MethodHandle makeEmptyList = MethodHandles.constant(List.class, Arrays.asList());
-MethodHandle asList = lookup()
-  .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class));
-
-JavaDocExamplesTest.asList = asList;
-/*
-static MethodHandle collectingTypeHandler(MethodHandle base, MethodType newType) {
-  return asList.asCollector(Object[].class, newType.parameterCount()).asType(newType);
-}
-*/
-
-MethodHandle collectingTypeHandler = lookup()
-  .findStatic(lookup().lookupClass(), "collectingTypeHandler",
-     methodType(MethodHandle.class, MethodHandle.class, MethodType.class));
-MethodHandle makeAnyList = makeEmptyList.withTypeHandler(collectingTypeHandler);
-
-assertEquals("[]", makeAnyList.invokeGeneric().toString());
-assertEquals("[1]", makeAnyList.invokeGeneric(1).toString());
-assertEquals("[two, too]", makeAnyList.invokeGeneric("two", "too").toString());
+Object x, y; String s; int i;
+MethodType mt; MethodHandle mh;
+MethodHandles.Lookup lookup = MethodHandles.lookup();
+// mt is (char,char)String
+mt = MethodType.methodType(String.class, char.class, char.class);
+mh = lookup.findVirtual(String.class, "replace", mt);
+// (Ljava/lang/String;CC)Ljava/lang/String;
+s = (String) mh.invokeExact("daddy",'d','n');
+assert(s.equals("nanny"));
+// weakly typed invocation (using MHs.invoke)
+s = (String) mh.invokeWithArguments("sappy", 'p', 'v');
+assert(s.equals("savvy"));
+// mt is (Object[])List
+mt = MethodType.methodType(java.util.List.class, Object[].class);
+mh = lookup.findStatic(java.util.Arrays.class, "asList", mt);
+assert(mh.isVarargsCollector());
+x = mh.invokeGeneric("one", "two");
+assert(x.equals(java.util.Arrays.asList("one","two")));
+// mt is (Object,Object,Object)Object
+mt = MethodType.genericMethodType(3);
+mh = MethodHandles.collectArguments(mh, mt);
+// mt is (Object,Object,Object)Object
+// (Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
+x = mh.invokeExact((Object)1, (Object)2, (Object)3);
+assert(x.equals(java.util.Arrays.asList(1,2,3)));
+// mt is { => int}
+mt = MethodType.methodType(int.class);
+mh = lookup.findVirtual(java.util.List.class, "size", mt);
+// (Ljava/util/List;)I
+i = (int) mh.invokeExact(java.util.Arrays.asList(1,2,3));
+assert(i == 3);
+mt = MethodType.methodType(void.class, String.class);
+mh = lookup.findVirtual(java.io.PrintStream.class, "println", mt);
+mh.invokeExact(System.out, "Hello, world.");
+{}
             }}
     }
 
-static MethodHandle collectingTypeHandler(MethodHandle base, MethodType newType) {
-    //System.out.println("Converting "+asList+" to "+newType);
-    MethodHandle conv = asList.asCollector(Object[].class, newType.parameterCount()).asType(newType);
-    //System.out.println(" =>"+conv);
-    return conv;
-}
+    @Test public void testAsVarargsCollector() throws Throwable {
+        {{
+{} /// JAVADOC
+MethodHandle asList = publicLookup()
+  .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
+  .asVarargsCollector(Object[].class);
+assertEquals("[]", asList.invokeGeneric().toString());
+assertEquals("[1]", asList.invokeGeneric(1).toString());
+assertEquals("[two, too]", asList.invokeGeneric("two", "too").toString());
+Object[] argv = { "three", "thee", "tee" };
+assertEquals("[three, thee, tee]", asList.invokeGeneric(argv).toString());
+List ls = (List) asList.invokeGeneric((Object)argv);
+assertEquals(1, ls.size());
+assertEquals("[three, thee, tee]", Arrays.toString((Object[])ls.get(0)));
+            }}
+    }
 
+    @Test public void testVarargsCollectorSuppression() throws Throwable {
+        {{
+{} /// JAVADOC
+MethodHandle vamh = publicLookup()
+  .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
+  .asVarargsCollector(Object[].class);
+MethodHandle invokeExact = publicLookup()
+  .findVirtual(MethodHandle.class, "invokeExact", vamh.type());
+MethodHandle mh = invokeExact.bindTo(vamh);
+assert(vamh.type().equals(mh.type()));
+assertEquals("[1, 2, 3]", vamh.invokeGeneric(1,2,3).toString());
+boolean failed = false;
+try { mh.invokeGeneric(1,2,3); }
+catch (WrongMethodTypeException ex) { failed = true; }
+assert(failed);
+{}
+            }}
+    }
 }

test/java/dyn/MethodHandlesTest.java

 /*
- * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1108,18 +1108,6 @@ public class MethodHandlesTest {
         }
     }
 
-    static MethodHandle typeHandler2(MethodHandle target, MethodType newType) {
-        MethodType oldType = target.type();
-        int oldArity = oldType.parameterCount();
-        int newArity = newType.parameterCount();
-        if (newArity < oldArity)
-            return MethodHandles.insertArguments(target, oldArity, "OPTIONAL");
-        else if (newArity > oldArity)
-            return MethodHandles.dropArguments(target, oldArity-1, newType.parameterType(oldArity-1));
-        else
-            return target;  // attempt no further conversions
-    }
-
     @Test
     public void testConvertArguments() throws Throwable {
         if (CAN_SKIP_WORKING)  return;
@@ -1137,23 +1125,6 @@ public class MethodHandlesTest {
         testConvert(true, true,  id, rtype, name, params);
     }
 
-    @Test
-    public void testTypeHandler() throws Throwable {
-        MethodHandle id = Callee.ofType(1);
-        MethodHandle th2 = PRIVATE.findStatic(MethodHandlesTest.class, "typeHandler2",
-                               MethodType.methodType(MethodHandle.class, MethodHandle.class, MethodType.class));
-        MethodHandle id2 = id.withTypeHandler(th2);
-        testConvert(true,  false, id2, null, "id", Object.class);
-        testConvert(true,  true,  id2, null, "id", Object.class);
-        if (true)  return;  //FIXME
-        testConvert(true,  false, id2, null, "id", String.class);  // FIXME: throws WMT
-        testConvert(false, true,  id2, null, "id", String.class);  // FIXME: should not succeed
-        testConvert(false, false, id2, null, "id", Object.class, String.class); //FIXME: array[1] line 1164
-        testConvert(true,  true,  id2, null, "id", Object.class, String.class);
-        testConvert(false, false, id2, null, "id");
-        testConvert(true,  true,  id2, null, "id");
-    }
-
     void testConvert(boolean positive, boolean useAsType,
                      MethodHandle id, Class<?> rtype, String name, Class<?>... params) throws Throwable {
         countTest(positive);
@@ -1183,9 +1154,9 @@ public class MethodHandlesTest {
         RuntimeException error = null;
         try {
             if (useAsType)
-                target = MethodHandles.convertArguments(id, newType);
-            else
                 target = id.asType(newType);
+            else
+                target = MethodHandles.convertArguments(id, newType);
         } catch (RuntimeException ex) {
             error = ex;
         }
@@ -1204,6 +1175,20 @@ public class MethodHandlesTest {
             System.out.print(':');
     }
 
+    @Test
+    public void testVarargsCollector() throws Throwable {
+        MethodHandle vac0 = PRIVATE.findStatic(MethodHandlesTest.class, "called",
+                               MethodType.methodType(Object.class, String.class, Object[].class));
+        vac0 = vac0.bindTo("vac");
+        MethodHandle vac = vac0.asVarargsCollector(Object[].class);
+        testConvert(true,  true,  vac.asType(MethodType.genericMethodType(0)), null, "vac");
+        testConvert(true,  true,  vac.asType(MethodType.genericMethodType(0)), null, "vac");
+        for (Class<?> at : new Class[] { Object.class, String.class, Integer.class }) {
+            testConvert(true,  true,  vac.asType(MethodType.genericMethodType(1)), null, "vac", at);
+            testConvert(true,  true,  vac.asType(MethodType.genericMethodType(2)), null, "vac", at, at);
+        }
+    }
+
     @Test
     public void testPermuteArguments() throws Throwable {
         if (CAN_SKIP_WORKING)  return;
@@ -1644,14 +1629,14 @@ public class MethodHandlesTest {
         assertCalled("invokee", args);
         // varargs invoker #0
         calledLog.clear();
-        inv = MethodHandles.varargsInvoker(type, 0);
+        inv = MethodHandles.spreadInvoker(type, 0);
         result = inv.invokeExact(target, args);
         if (testRetCode)  assertEquals(code, result);
         assertCalled("invokee", args);
         if (nargs >= 1) {
             // varargs invoker #1
             calledLog.clear();
-            inv = MethodHandles.varargsInvoker(type, 1);
+            inv = MethodHandles.spreadInvoker(type, 1);
             result = inv.invokeExact(target, args[0], Arrays.copyOfRange(args, 1, nargs));
             if (testRetCode)  assertEquals(code, result);
             assertCalled("invokee", args);
@@ -1659,7 +1644,7 @@ public class MethodHandlesTest {
         if (nargs >= 2) {
             // varargs invoker #2
             calledLog.clear();
-            inv = MethodHandles.varargsInvoker(type, 2);
+            inv = MethodHandles.spreadInvoker(type, 2);
             result = inv.invokeExact(target, args[0], args[1], Arrays.copyOfRange(args, 2, nargs));
             if (testRetCode)  assertEquals(code, result);
             assertCalled("invokee", args);
@@ -1667,7 +1652,7 @@ public class MethodHandlesTest {
         if (nargs >= 3) {
             // varargs invoker #3
             calledLog.clear();
-            inv = MethodHandles.varargsInvoker(type, 3);
+            inv = MethodHandles.spreadInvoker(type, 3);
             result = inv.invokeExact(target, args[0], args[1], args[2], Arrays.copyOfRange(args, 3, nargs));
             if (testRetCode)  assertEquals(code, result);
             assertCalled("invokee", args);
@@ -1676,7 +1661,7 @@ public class MethodHandlesTest {
             // varargs invoker #0..N
             countTest();
             calledLog.clear();
-            inv = MethodHandles.varargsInvoker(type, k);
+            inv = MethodHandles.spreadInvoker(type, k);
             List<Object> targetPlusVarArgs = new ArrayList<Object>(targetPlusArgs);
             List<Object> tailList = targetPlusVarArgs.subList(1+k, 1+nargs);
             Object[] tail = tailList.toArray();
@@ -2089,19 +2074,6 @@ public class MethodHandlesTest {
             }
         }
         // Test error checking:
-        MethodHandle genericMH = ValueConversions.varargsArray(0);
-        genericMH = MethodHandles.convertArguments(genericMH, genericMH.type().generic());
-        for (Class<?> sam : new Class[] { Runnable.class,
-                                          Fooable.class,
-                                          Iterable.class }) {
-            try {
-                // Must throw, because none of these guys has generic type.
-                MethodHandles.asInstance(genericMH, sam);
-                System.out.println("Failed to throw");
-                assertTrue(false);
-            } catch (IllegalArgumentException ex) {
-            }
-        }
         for (Class<?> nonSAM : new Class[] { Object.class,
                                              String.class,
                                              CharSequence.class,

test/java/dyn/indify/Indify.java

@@ -98,8 +98,9 @@ $ $JAVA_HOME/bin/java -XX:+UnlockExperimentalVMOptions -XX:+EnableInvokeDynamic
 (same output as above)
  * </pre></blockquote>
  * <p>
- * Until the format of {@code CONSTANT_InvokeDynamic} entries is finalized,
- * the {@code --transitionalJSR292} switch is recommended (and turned on by default).
+ * Before OpenJDK build b123, the format of {@code CONSTANT_InvokeDynamic} is in transition,
+ * and the switch {@code --transitionalJSR292=yes} is recommended.
+ * It is turned <em>off</em> by default, but users of earlier builds may need to turn it on.
  * <p>
  * A version of this transformation built on top of <a href="http://asm.ow2.org/">http://asm.ow2.org/</a> would be welcome.
  * @author John Rose
@@ -116,7 +117,7 @@ public class Indify {
     public boolean overwrite = false;
     public boolean quiet = false;
     public boolean verbose = false;
-    public boolean transitionalJSR292 = true;  // default to false later
+    public boolean transitionalJSR292 = false;  // final version is distributed
     public boolean all = false;
     public int verifySpecifierCount = -1;
 
@@ -158,6 +159,7 @@ public class Indify {
         av = avl.toArray(new String[0]);
         Class<?> mainClass = Class.forName(mainClassName, true, makeClassLoader());
         java.lang.reflect.Method main = mainClass.getMethod("main", String[].class);
+        try { main.setAccessible(true); } catch (SecurityException ex) { }
         main.invoke(null, (Object) av);
     }
 
@@ -223,8 +225,8 @@ public class Indify {
     private boolean booleanOption(String s) {
         if (s == null)  return true;
         switch (s) {
-        case "true":  case "yes": case "1": return true;
-        case "false": case "no":  case "0": return false;
+        case "true":  case "yes": case "on":  case "1": return true;
+        case "false": case "no":  case "off": case "0": return false;
         }
         throw new IllegalArgumentException("unrecognized boolean flag="+s);
     }
@@ -284,7 +286,7 @@ public class Indify {
     }
 
     File classPathFile(File pathDir, String className) {
-        String qualname = className+".class";
+        String qualname = className.replace('.','/')+".class";
         qualname = qualname.replace('/', File.separatorChar);
         return new File(pathDir, qualname);
     }
@@ -339,6 +341,7 @@ public class Indify {
         private File findClassInPath(String name) {
             for (String s : classpath) {
                 File f = classPathFile(new File(s), name);
+                //System.out.println("Checking for "+f);
                 if (f.exists() && f.canRead()) {
                     return f;
                 }
@@ -353,11 +356,11 @@ public class Indify {
             }
         }
         private Class<?> transformAndLoadClass(File f) throws ClassNotFoundException, IOException {
-            if (verbose)  System.out.println("Loading class from "+f);
+            if (verbose)  System.err.println("Loading class from "+f);
             ClassFile cf = new ClassFile(f);
             Logic logic = new Logic(cf);
             boolean changed = logic.transform();
-            if (verbose && !changed)  System.out.println("(no change)");
+            if (verbose && !changed)  System.err.println("(no change)");
             logic.reportPatternMethods(!verbose, keepgoing);
             byte[] bytes = cf.toByteArray();
             return defineClass(null, bytes, 0, bytes.length);
@@ -525,6 +528,7 @@ public class Indify {
                     throw new IllegalArgumentException("BootstrapMethods length is "+specsLen+" but should be "+verifySpecifierCount);
                 }
             }
+            if (!quiet)  System.err.flush();
         }
 
         // mark constant pool entries according to participation in patterns
@@ -696,6 +700,18 @@ public class Indify {
                     args.clear();
                     break;
 
+                case opc_new:
+                {
+                    String type = pool.getString(CONSTANT_Class, (short)i.u2At(1));
+                    //System.out.println("new "+type);
+                    switch (type) {
+                    case "java/lang/StringBuilder":
+                        jvm.push("StringBuilder");
+                        continue decode;  // go to next instruction
+                    }
+                    break decode;  // bail out
+                }
+
                 case opc_getstatic:
                 {
                     // int.class compiles to getstatic Integer.TYPE
@@ -732,8 +748,9 @@ public class Indify {
 
                 case opc_invokestatic:
                 case opc_invokevirtual:
+                case opc_invokespecial:
                 {
-                    boolean hasRecv = (bc == opc_invokevirtual);
+                    boolean hasRecv = (bc != opc_invokestatic);
                     int methi = i.u2At(1);
                     char mark = poolMarks[methi];
                     Short[] ref = pool.getMemberRef((short)methi);
@@ -770,6 +787,7 @@ public class Indify {
                     if (mark == 'T' || mark == 'H' || mark == 'I') {
                         ownMethod = findMember(cf.methods, ref[1], ref[2]);
                     }
+                    //if (intrinsic != null)  System.out.println("intrinsic = "+intrinsic);
                     switch (intrinsic == null ? "" : intrinsic) {
                     case "fromMethodDescriptorString":
                         con = makeMethodTypeCon(args.get(0));
@@ -860,6 +878,15 @@ public class Indify {
                             }
                         }
                         break decode;
+                    case "StringBuilder.append":
+                        // allow calls like ("value = "+x)
+                        removeEmptyJVMSlots(args);
+                        args.subList(1, args.size()).clear();
+                        continue;
+                    case "StringBuilder.toString":
+                        args.clear();
+                        args.add(intrinsic);
+                        continue;
                     }
                     if (!hasRecv && ownMethod != null && patternMark != 0) {
                         con = constants.get(ownMethod);
@@ -1506,6 +1533,7 @@ public class Indify {
                 out.write(bytes);
             } else {
                 trueSize = flatten(out);
+                //if (!(item instanceof Code))  System.err.println("wrote complex attr name="+(int)(char)name+" size="+trueSize+" data="+Arrays.toString(flatten()));
             }
             if (trueSize != size && size >= 0)
                 System.err.println("warning: attribute size changed "+size+" to "+trueSize);
@@ -1525,7 +1553,7 @@ public class Indify {
         }
         public List<Attr> attrs() { return null; }  // Code overrides this
         public byte[] flatten() {
-            ByteArrayOutputStream buf = new ByteArrayOutputStream(size);
+            ByteArrayOutputStream buf = new ByteArrayOutputStream(Math.max(20, size));
             flatten(buf);
             return buf.toByteArray();
         }
@@ -1642,6 +1670,7 @@ public class Indify {
         opc_invokestatic           = 184,
         opc_invokeinterface        = 185,
         opc_invokedynamic          = 186,
+        opc_new                    = 187,
         opc_anewarray              = 189,
         opc_checkcast              = 192,
         opc_ifnull                 = 198,