changeset 40408:cf7e826d4d63

8164044: Generate corresponding simple DelegatingMethodHandles when generating a DirectMethodHandle at link time Reviewed-by: vlivanov, mhaupt, shade
author redestad
date Thu, 18 Aug 2016 19:00:39 +0200
parents 80a7336fe4cd
children 564ea8deef3c
files jdk/src/java.base/share/classes/java/lang/invoke/BoundMethodHandle.java jdk/src/java.base/share/classes/java/lang/invoke/DelegatingMethodHandle.java jdk/src/java.base/share/classes/java/lang/invoke/DirectMethodHandle.java jdk/src/java.base/share/classes/java/lang/invoke/GenerateJLIClassesHelper.java jdk/src/java.base/share/classes/java/lang/invoke/InvokerBytecodeGenerator.java jdk/src/java.base/share/classes/java/lang/invoke/LambdaForm.java jdk/src/java.base/share/classes/java/lang/invoke/MethodHandleImpl.java jdk/src/java.base/share/classes/jdk/internal/misc/JavaLangInvokeAccess.java jdk/src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/GenerateJLIClassesPlugin.java jdk/test/java/lang/StackWalker/VerifyStackTrace.java
diffstat 10 files changed, 254 insertions(+), 76 deletions(-) [+]
line wrap: on
line diff
--- a/jdk/src/java.base/share/classes/java/lang/invoke/BoundMethodHandle.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/src/java.base/share/classes/java/lang/invoke/BoundMethodHandle.java	Thu Aug 18 19:00:39 2016 +0200
@@ -36,7 +36,6 @@
 import java.lang.invoke.LambdaForm.NamedFunction;
 import java.lang.invoke.MethodHandles.Lookup;
 import java.lang.reflect.Field;
-import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.function.Function;
@@ -308,7 +307,7 @@
         /*non-public*/ char fieldTypeChar(int i) {
             return typeChars.charAt(i);
         }
-        Object fieldSignature() {
+        String fieldSignature() {
             return typeChars;
         }
         public Class<? extends BoundMethodHandle> fieldHolder() {
--- a/jdk/src/java.base/share/classes/java/lang/invoke/DelegatingMethodHandle.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/src/java.base/share/classes/java/lang/invoke/DelegatingMethodHandle.java	Thu Aug 18 19:00:39 2016 +0200
@@ -27,6 +27,7 @@
 
 import java.util.Arrays;
 import static java.lang.invoke.LambdaForm.*;
+import static java.lang.invoke.LambdaForm.Kind.*;
 import static java.lang.invoke.MethodHandleStatics.*;
 
 /**
@@ -96,14 +97,8 @@
                                         int whichCache,
                                         Object constraint,
                                         NamedFunction getTargetFn) {
-        String debugString;
-        switch(whichCache) {
-            case MethodTypeForm.LF_REBIND:            debugString = "BMH.reinvoke";      break;
-            case MethodTypeForm.LF_DELEGATE:          debugString = "MH.delegate";       break;
-            default:                                  debugString = "MH.reinvoke";       break;
-        }
         // No pre-action needed.
-        return makeReinvokerForm(target, whichCache, constraint, debugString, true, getTargetFn, null);
+        return makeReinvokerForm(target, whichCache, constraint, null, true, getTargetFn, null);
     }
     /** Create a LF which simply reinvokes a target of the given basic type. */
     static LambdaForm makeReinvokerForm(MethodHandle target,
@@ -114,6 +109,10 @@
                                         NamedFunction getTargetFn,
                                         NamedFunction preActionFn) {
         MethodType mtype = target.type().basicType();
+        Kind kind = whichKind(whichCache);
+        if (debugString == null) {
+            debugString = kind.defaultLambdaName;
+        }
         boolean customized = (whichCache < 0 ||
                 mtype.parameterSlotCount() > MethodType.MAX_MH_INVOKER_ARITY);
         boolean hasPreAction = (preActionFn != null);
@@ -145,13 +144,21 @@
             targetArgs[0] = names[NEXT_MH];  // overwrite this MH with next MH
             names[REINVOKE] = new LambdaForm.Name(mtype, targetArgs);
         }
-        form = new LambdaForm(debugString, ARG_LIMIT, names, forceInline);
+        form = new LambdaForm(debugString, ARG_LIMIT, names, forceInline, kind);
         if (!customized) {
             form = mtype.form().setCachedLambdaForm(whichCache, form);
         }
         return form;
     }
 
+    private static Kind whichKind(int whichCache) {
+        switch(whichCache) {
+            case MethodTypeForm.LF_REBIND:   return BOUND_REINVOKER;
+            case MethodTypeForm.LF_DELEGATE: return DELEGATE;
+            default:                         return REINVOKER;
+        }
+    }
+
     static final NamedFunction NF_getTarget;
     static {
         try {
@@ -160,5 +167,13 @@
         } catch (ReflectiveOperationException ex) {
             throw newInternalError(ex);
         }
+        // The Holder class will contain pre-generated DelegatingMethodHandles resolved
+        // speculatively using MemberName.getFactory().resolveOrNull. However, that
+        // doesn't initialize the class, which subtly breaks inlining etc. By forcing
+        // initialization of the Holder class we avoid these issues.
+        UNSAFE.ensureClassInitialized(Holder.class);
     }
+
+    /* Placeholder class for DelegatingMethodHandles generated ahead of time */
+    final class Holder {}
 }
--- a/jdk/src/java.base/share/classes/java/lang/invoke/DirectMethodHandle.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/src/java.base/share/classes/java/lang/invoke/DirectMethodHandle.java	Thu Aug 18 19:00:39 2016 +0200
@@ -38,6 +38,7 @@
 import java.util.Objects;
 
 import static java.lang.invoke.LambdaForm.*;
+import static java.lang.invoke.LambdaForm.Kind.*;
 import static java.lang.invoke.MethodHandleNatives.Constants.*;
 import static java.lang.invoke.MethodHandleStatics.UNSAFE;
 import static java.lang.invoke.MethodHandleStatics.newInternalError;
@@ -189,14 +190,15 @@
     static LambdaForm makePreparedLambdaForm(MethodType mtype, int which) {
         boolean needsInit = (which == LF_INVSTATIC_INIT);
         boolean doesAlloc = (which == LF_NEWINVSPECIAL);
-        String linkerName, lambdaName;
+        String linkerName;
+        LambdaForm.Kind kind;
         switch (which) {
-        case LF_INVVIRTUAL:    linkerName = "linkToVirtual";    lambdaName = "DMH.invokeVirtual";    break;
-        case LF_INVSTATIC:     linkerName = "linkToStatic";     lambdaName = "DMH.invokeStatic";     break;
-        case LF_INVSTATIC_INIT:linkerName = "linkToStatic";     lambdaName = "DMH.invokeStaticInit"; break;
-        case LF_INVSPECIAL:    linkerName = "linkToSpecial";    lambdaName = "DMH.invokeSpecial";    break;
-        case LF_INVINTERFACE:  linkerName = "linkToInterface";  lambdaName = "DMH.invokeInterface";  break;
-        case LF_NEWINVSPECIAL: linkerName = "linkToSpecial";    lambdaName = "DMH.newInvokeSpecial"; break;
+        case LF_INVVIRTUAL:    linkerName = "linkToVirtual";   kind = DIRECT_INVOKE_VIRTUAL;     break;
+        case LF_INVSTATIC:     linkerName = "linkToStatic";    kind = DIRECT_INVOKE_STATIC;      break;
+        case LF_INVSTATIC_INIT:linkerName = "linkToStatic";    kind = DIRECT_INVOKE_STATIC_INIT; break;
+        case LF_INVSPECIAL:    linkerName = "linkToSpecial";   kind = DIRECT_INVOKE_SPECIAL;     break;
+        case LF_INVINTERFACE:  linkerName = "linkToInterface"; kind = DIRECT_INVOKE_INTERFACE;   break;
+        case LF_NEWINVSPECIAL: linkerName = "linkToSpecial";   kind = DIRECT_NEW_INVOKE_SPECIAL; break;
         default:  throw new InternalError("which="+which);
         }
 
@@ -240,11 +242,11 @@
             result = NEW_OBJ;
         }
         names[LINKER_CALL] = new Name(linker, outArgs);
-        lambdaName += "_" + shortenSignature(basicTypeSignature(mtype));
-        LambdaForm lform = new LambdaForm(lambdaName, ARG_LIMIT, names, result);
+        String lambdaName = kind.defaultLambdaName + "_" + shortenSignature(basicTypeSignature(mtype));
+        LambdaForm lform = new LambdaForm(lambdaName, ARG_LIMIT, names, result, kind);
 
         // This is a tricky bit of code.  Don't send it through the LF interpreter.
-        lform.compileToBytecode(Holder.class);
+        lform.compileToBytecode();
         return lform;
     }
 
@@ -705,7 +707,7 @@
     }
 
     static {
-        // The DMH class will contain pre-generated DirectMethodHandles resolved
+        // The Holder class will contain pre-generated DirectMethodHandles resolved
         // speculatively using MemberName.getFactory().resolveOrNull. However, that
         // doesn't initialize the class, which subtly breaks inlining etc. By forcing
         // initialization of the Holder class we avoid these issues.
@@ -713,5 +715,5 @@
     }
 
     /* Placeholder class for DirectMethodHandles generated ahead of time */
-    private final class Holder {}
+    final class Holder {}
 }
--- a/jdk/src/java.base/share/classes/java/lang/invoke/GenerateJLIClassesHelper.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/src/java.base/share/classes/java/lang/invoke/GenerateJLIClassesHelper.java	Thu Aug 18 19:00:39 2016 +0200
@@ -29,21 +29,56 @@
 import jdk.internal.org.objectweb.asm.ClassWriter;
 import jdk.internal.org.objectweb.asm.Opcodes;
 
+import java.util.ArrayList;
+import java.util.HashSet;
+
 /**
  * Helper class to assist the GenerateJLIClassesPlugin to get access to
  * generate classes ahead of time.
  */
 class GenerateJLIClassesHelper {
 
-    static byte[] generateDMHClassBytes(String className,
+    static byte[] generateDirectMethodHandleHolderClassBytes(String className,
             MethodType[] methodTypes, int[] types) {
         LambdaForm[] forms = new LambdaForm[methodTypes.length];
+        String[] names = new String[methodTypes.length];
         for (int i = 0; i < forms.length; i++) {
             forms[i] = DirectMethodHandle.makePreparedLambdaForm(methodTypes[i],
                                                                  types[i]);
-            methodTypes[i] = forms[i].methodType();
+            names[i] = forms[i].kind.defaultLambdaName;
         }
-        return generateCodeBytesForLFs(className, forms, methodTypes);
+        return generateCodeBytesForLFs(className, names, forms);
+    }
+
+    static byte[] generateDelegatingMethodHandleHolderClassBytes(String className,
+            MethodType[] methodTypes) {
+
+        HashSet<MethodType> dedupSet = new HashSet<>();
+        ArrayList<LambdaForm> forms = new ArrayList<>();
+        ArrayList<String> names = new ArrayList<>();
+        for (int i = 0; i < methodTypes.length; i++) {
+            // generate methods representing the DelegatingMethodHandle
+            if (dedupSet.add(methodTypes[i])) {
+                // reinvokers are variant with the associated SpeciesData
+                // and shape of the target LF, but we can easily pregenerate
+                // the basic reinvokers associated with Species_L. Ultimately we
+                // may want to consider pregenerating more of these, which will
+                // require an even more complex naming scheme
+                LambdaForm reinvoker = makeReinvokerFor(methodTypes[i]);
+                forms.add(reinvoker);
+                String speciesSig = BoundMethodHandle
+                        .speciesData(reinvoker).fieldSignature();
+                assert(speciesSig.equals("L"));
+                names.add(reinvoker.kind.defaultLambdaName + "_" + speciesSig);
+
+                LambdaForm delegate = makeDelegateFor(methodTypes[i]);
+                forms.add(delegate);
+                names.add(delegate.kind.defaultLambdaName);
+            }
+        }
+        return generateCodeBytesForLFs(className,
+                names.toArray(new String[0]),
+                forms.toArray(new LambdaForm[0]));
     }
 
     /*
@@ -51,22 +86,45 @@
      * a class with a specified name.
      */
     private static byte[] generateCodeBytesForLFs(String className,
-            LambdaForm[] forms, MethodType[] types) {
-        assert(forms.length == types.length);
+            String[] names, LambdaForm[] forms) {
 
         ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
         cw.visit(Opcodes.V1_8, Opcodes.ACC_PRIVATE + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
                 className, null, InvokerBytecodeGenerator.INVOKER_SUPER_NAME, null);
         cw.visitSource(className.substring(className.lastIndexOf('/') + 1), null);
+
         for (int i = 0; i < forms.length; i++) {
-            InvokerBytecodeGenerator g
-                    = new InvokerBytecodeGenerator(className, forms[i], types[i]);
-            g.setClassWriter(cw);
-            g.addMethod();
+            addMethod(className, names[i], forms[i],
+                    forms[i].methodType(), cw);
         }
         return cw.toByteArray();
     }
 
+    private static void addMethod(String className, String methodName, LambdaForm form,
+            MethodType type, ClassWriter cw) {
+        InvokerBytecodeGenerator g
+                = new InvokerBytecodeGenerator(className, methodName, form, type);
+        g.setClassWriter(cw);
+        g.addMethod();
+    }
+
+    private static LambdaForm makeReinvokerFor(MethodType type) {
+        MethodHandle emptyHandle = MethodHandles.empty(type);
+        return DelegatingMethodHandle.makeReinvokerForm(emptyHandle,
+                MethodTypeForm.LF_REBIND,
+                BoundMethodHandle.speciesData_L(),
+                BoundMethodHandle.speciesData_L().getterFunction(0));
+    }
+
+    private static LambdaForm makeDelegateFor(MethodType type) {
+        MethodHandle handle = MethodHandles.empty(type);
+        return DelegatingMethodHandle.makeReinvokerForm(
+                handle,
+                MethodTypeForm.LF_DELEGATE,
+                DelegatingMethodHandle.class,
+                DelegatingMethodHandle.NF_getTarget);
+    }
+
     static Map.Entry<String, byte[]> generateConcreteBMHClassBytes(
             final String types) {
         for (char c : types.toCharArray()) {
--- a/jdk/src/java.base/share/classes/java/lang/invoke/InvokerBytecodeGenerator.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/src/java.base/share/classes/java/lang/invoke/InvokerBytecodeGenerator.java	Thu Aug 18 19:00:39 2016 +0200
@@ -46,6 +46,7 @@
 
 import static java.lang.invoke.LambdaForm.*;
 import static java.lang.invoke.LambdaForm.BasicType.*;
+import static java.lang.invoke.LambdaForm.Kind.*;
 import static java.lang.invoke.MethodHandleNatives.Constants.*;
 import static java.lang.invoke.MethodHandleStatics.*;
 
@@ -125,9 +126,15 @@
     }
 
     /** For generating customized code for a single LambdaForm. */
-    InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
+    private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
+        this(className, form.debugName, form, invokerType);
+    }
+
+    /** For generating customized code for a single LambdaForm. */
+    InvokerBytecodeGenerator(String className, String invokerName,
+            LambdaForm form, MethodType invokerType) {
         this(form, form.names.length,
-             className, form.debugName, invokerType);
+             className, invokerName, invokerType);
         // Create an array to map name indexes to locals indexes.
         Name[] names = form.names;
         for (int i = 0, index = 0; i < localsMap.length; i++) {
@@ -597,10 +604,42 @@
         return c.getName().replace('.', '/');
     }
 
+    private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
+        MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
+        MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);
+
+        return resolvedMember;
+    }
+
+    private static MemberName lookupPregenerated(LambdaForm form) {
+        if (form.customized != null) {
+            // No pre-generated version for customized LF
+            return null;
+        }
+        MethodType invokerType = form.methodType();
+        String name = form.kind.methodName;
+        switch (form.kind) {
+            case BOUND_REINVOKER: {
+                name = name + "_" + BoundMethodHandle.speciesData(form).fieldSignature();
+                return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
+            }
+            case DELEGATE:                  return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
+            case DIRECT_INVOKE_INTERFACE:   // fall-through
+            case DIRECT_INVOKE_SPECIAL:     // fall-through
+            case DIRECT_INVOKE_STATIC:      // fall-through
+            case DIRECT_INVOKE_STATIC_INIT: // fall-through
+            case DIRECT_INVOKE_VIRTUAL:     return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class);
+        }
+        return null;
+    }
+
     /**
      * Generate customized bytecode for a given LambdaForm.
      */
     static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
+        MemberName pregenerated = lookupPregenerated(form);
+        if (pregenerated != null)  return pregenerated; // pre-generated bytecode
+
         InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
         return g.loadMethod(g.generateCustomizedCodeBytes());
     }
--- a/jdk/src/java.base/share/classes/java/lang/invoke/LambdaForm.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/src/java.base/share/classes/java/lang/invoke/LambdaForm.java	Thu Aug 18 19:00:39 2016 +0200
@@ -41,6 +41,7 @@
 import static java.lang.invoke.LambdaForm.BasicType.*;
 import static java.lang.invoke.MethodHandleNatives.Constants.REF_invokeStatic;
 import static java.lang.invoke.MethodHandleStatics.*;
+import java.util.Objects;
 
 /**
  * The symbolic, non-executable form of a method handle's invocation semantics.
@@ -127,6 +128,7 @@
     final MethodHandle customized;
     @Stable final Name[] names;
     final String debugName;
+    final Kind kind;
     MemberName vmentry;   // low-level behavior, or null if not yet prepared
     private boolean isCompiled;
 
@@ -266,12 +268,46 @@
         }
     }
 
+    enum Kind {
+        GENERIC(""),
+        BOUND_REINVOKER("BMH.reinvoke"),
+        REINVOKER("MH.reinvoke"),
+        DELEGATE("MH.delegate"),
+        DIRECT_INVOKE_VIRTUAL("DMH.invokeVirtual"),
+        DIRECT_INVOKE_SPECIAL("DMH.invokeSpecial"),
+        DIRECT_INVOKE_STATIC("DMH.invokeStatic"),
+        DIRECT_NEW_INVOKE_SPECIAL("DMH.newInvokeSpecial"),
+        DIRECT_INVOKE_INTERFACE("DMH.invokeInterface"),
+        DIRECT_INVOKE_STATIC_INIT("DMH.invokeStaticInit");
+
+        final String defaultLambdaName;
+        final String methodName;
+
+        private Kind(String defaultLambdaName) {
+            this.defaultLambdaName = defaultLambdaName;
+            int p = defaultLambdaName.indexOf('.');
+            if (p > -1) {
+                this.methodName = defaultLambdaName.substring(p + 1);
+            } else {
+                this.methodName = defaultLambdaName;
+            }
+        }
+    }
+
     LambdaForm(String debugName,
                int arity, Name[] names, int result) {
-        this(debugName, arity, names, result, /*forceInline=*/true, /*customized=*/null);
+        this(debugName, arity, names, result, /*forceInline=*/true, /*customized=*/null, Kind.GENERIC);
+    }
+    LambdaForm(String debugName,
+               int arity, Name[] names, int result, Kind kind) {
+        this(debugName, arity, names, result, /*forceInline=*/true, /*customized=*/null, kind);
     }
     LambdaForm(String debugName,
                int arity, Name[] names, int result, boolean forceInline, MethodHandle customized) {
+        this(debugName, arity, names, result, forceInline, customized, Kind.GENERIC);
+    }
+    LambdaForm(String debugName,
+               int arity, Name[] names, int result, boolean forceInline, MethodHandle customized, Kind kind) {
         assert(namesOK(arity, names));
         this.arity = arity;
         this.result = fixResult(result, names);
@@ -279,6 +315,7 @@
         this.debugName = fixDebugName(debugName);
         this.forceInline = forceInline;
         this.customized = customized;
+        this.kind = kind;
         int maxOutArity = normalize();
         if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
             // Cannot use LF interpreter on very high arity expressions.
@@ -288,11 +325,15 @@
     }
     LambdaForm(String debugName,
                int arity, Name[] names) {
-        this(debugName, arity, names, LAST_RESULT, /*forceInline=*/true, /*customized=*/null);
+        this(debugName, arity, names, LAST_RESULT, /*forceInline=*/true, /*customized=*/null, Kind.GENERIC);
     }
     LambdaForm(String debugName,
                int arity, Name[] names, boolean forceInline) {
-        this(debugName, arity, names, LAST_RESULT, forceInline, /*customized=*/null);
+        this(debugName, arity, names, LAST_RESULT, forceInline, /*customized=*/null, Kind.GENERIC);
+    }
+    LambdaForm(String debugName,
+               int arity, Name[] names, boolean forceInline, Kind kind) {
+        this(debugName, arity, names, LAST_RESULT, forceInline, /*customized=*/null, kind);
     }
     LambdaForm(String debugName,
                Name[] formals, Name[] temps, Name result) {
@@ -325,6 +366,7 @@
         this.debugName = "LF.zero";
         this.forceInline = true;
         this.customized = null;
+        this.kind = Kind.GENERIC;
         assert(nameRefsAreLegal());
         assert(isEmpty());
         String sig = null;
@@ -395,7 +437,7 @@
 
     /** Customize LambdaForm for a particular MethodHandle */
     LambdaForm customize(MethodHandle mh) {
-        LambdaForm customForm = new LambdaForm(debugName, arity, names, result, forceInline, mh);
+        LambdaForm customForm = new LambdaForm(debugName, arity, names, result, forceInline, mh, kind);
         if (COMPILE_THRESHOLD >= 0 && isCompiled) {
             // If shared LambdaForm has been compiled, compile customized version as well.
             customForm.compileToBytecode();
@@ -773,28 +815,6 @@
         }
     }
 
-    /**
-     * Generate optimizable bytecode for this form after first looking for a
-     * pregenerated version in a specified class.
-     */
-    void compileToBytecode(Class<?> lookupClass) {
-        if (vmentry != null && isCompiled) {
-            return;  // already compiled somehow
-        }
-        MethodType invokerType = methodType();
-        assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
-        int dot = debugName.indexOf('.');
-        String methodName = (dot > 0) ? debugName.substring(dot + 1) : debugName;
-        MemberName member = new MemberName(lookupClass, methodName, invokerType, REF_invokeStatic);
-        MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, lookupClass);
-        if (resolvedMember != null) {
-            vmentry = resolvedMember;
-            isCompiled = true;
-        } else {
-            compileToBytecode();
-        }
-    }
-
     private static void computeInitialPreparedForms() {
         // Find all predefined invokers and associate them with canonical empty lambda forms.
         for (MemberName m : MemberName.getFactory().getMethods(LambdaForm.class, false, null, null, null)) {
--- a/jdk/src/java.base/share/classes/java/lang/invoke/MethodHandleImpl.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/src/java.base/share/classes/java/lang/invoke/MethodHandleImpl.java	Thu Aug 18 19:00:39 2016 +0200
@@ -1718,10 +1718,19 @@
             }
 
             @Override
-            public byte[] generateDMHClassBytes(String className,
-            MethodType[] methodTypes, int[] types) {
+            public byte[] generateDirectMethodHandleHolderClassBytes(
+                    String className, MethodType[] methodTypes, int[] types) {
                 return GenerateJLIClassesHelper
-                        .generateDMHClassBytes(className, methodTypes, types);
+                        .generateDirectMethodHandleHolderClassBytes(
+                                className, methodTypes, types);
+            }
+
+            @Override
+            public byte[] generateDelegatingMethodHandleHolderClassBytes(
+                    String className, MethodType[] methodTypes) {
+                return GenerateJLIClassesHelper
+                        .generateDelegatingMethodHandleHolderClassBytes(
+                                className, methodTypes);
             }
 
             @Override
--- a/jdk/src/java.base/share/classes/jdk/internal/misc/JavaLangInvokeAccess.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/src/java.base/share/classes/jdk/internal/misc/JavaLangInvokeAccess.java	Thu Aug 18 19:00:39 2016 +0200
@@ -51,8 +51,17 @@
      * an {@code int} representing method type.  Used by
      * GenerateJLIClassesPlugin to generate such a class during the jlink phase.
      */
-    byte[] generateDMHClassBytes(String className, MethodType[] methodTypes,
-            int[] types);
+    byte[] generateDirectMethodHandleHolderClassBytes(String className,
+            MethodType[] methodTypes, int[] types);
+
+    /**
+     * Returns a {@code byte[]} containing the bytecode for a class implementing
+     * DelegatingMethodHandles of each {@code MethodType} kind in the
+     * {@code methodTypes} argument.  Used by GenerateJLIClassesPlugin to
+     * generate such a class during the jlink phase.
+     */
+    byte[] generateDelegatingMethodHandleHolderClassBytes(String className,
+            MethodType[] methodTypes);
 
     /**
      * Returns a {@code byte[]} containing the bytecode for a BoundMethodHandle
--- a/jdk/src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/GenerateJLIClassesPlugin.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/GenerateJLIClassesPlugin.java	Thu Aug 18 19:00:39 2016 +0200
@@ -55,7 +55,7 @@
 
     private static final String DESCRIPTION = PluginsResourceBundle.getDescription(NAME);
 
-    private static final String DMH = "java/lang/invoke/DirectMethodHandle$Holder";
+    private static final String DIRECT_METHOD_HANDLE = "java/lang/invoke/DirectMethodHandle$Holder";
     private static final String DMH_INVOKE_VIRTUAL = "invokeVirtual";
     private static final String DMH_INVOKE_STATIC = "invokeStatic";
     private static final String DMH_INVOKE_SPECIAL = "invokeSpecial";
@@ -63,6 +63,8 @@
     private static final String DMH_INVOKE_INTERFACE = "invokeInterface";
     private static final String DMH_INVOKE_STATIC_INIT = "invokeStaticInit";
 
+    private static final String DELEGATING_METHOD_HANDLE = "java/lang/invoke/DelegatingMethodHandle$Holder";
+
     private static final JavaLangInvokeAccess JLIA
             = SharedSecrets.getJavaLangInvokeAccess();
 
@@ -222,7 +224,15 @@
     @Override
     public ResourcePool transform(ResourcePool in, ResourcePoolBuilder out) {
         // Copy all but DMH_ENTRY to out
-        in.transformAndCopy(entry -> entry.path().equals(DMH_ENTRY) ? null : entry, out);
+        in.transformAndCopy(entry -> {
+                // filter out placeholder entries
+                if (entry.path().equals(DIRECT_METHOD_HANDLE_ENTRY) ||
+                    entry.path().equals(DELEGATING_METHOD_HANDLE_ENTRY)) {
+                    return null;
+                } else {
+                    return entry;
+                }
+            }, out);
         speciesTypes.forEach(types -> generateBMHClass(types, out));
         generateDMHClass(out);
         return out.build();
@@ -264,15 +274,24 @@
             }
         }
         try {
-            byte[] bytes =
-                    JLIA.generateDMHClassBytes(DMH, methodTypes, dmhTypes);
-            ResourcePoolEntry ndata = ResourcePoolEntry.create(DMH_ENTRY, bytes);
+            byte[] bytes = JLIA.generateDirectMethodHandleHolderClassBytes(
+                    DIRECT_METHOD_HANDLE, methodTypes, dmhTypes);
+            ResourcePoolEntry ndata = ResourcePoolEntry
+                    .create(DIRECT_METHOD_HANDLE_ENTRY, bytes);
+            out.add(ndata);
+
+            bytes = JLIA.generateDelegatingMethodHandleHolderClassBytes(
+                    DELEGATING_METHOD_HANDLE, methodTypes);
+            ndata = ResourcePoolEntry.create(DELEGATING_METHOD_HANDLE_ENTRY, bytes);
             out.add(ndata);
         } catch (Exception ex) {
             throw new PluginException(ex);
         }
     }
-    private static final String DMH_ENTRY = "/java.base/" + DMH + ".class";
+    private static final String DIRECT_METHOD_HANDLE_ENTRY =
+            "/java.base/" + DIRECT_METHOD_HANDLE + ".class";
+    private static final String DELEGATING_METHOD_HANDLE_ENTRY =
+            "/java.base/" + DELEGATING_METHOD_HANDLE + ".class";
 
     // Convert LL -> LL, L3 -> LLL
     private static String expandSignature(String signature) {
@@ -310,15 +329,19 @@
         assert(parts.length == 2);
         assert(parts[1].length() == 1);
         String parameters = expandSignature(parts[0]);
-        Class<?> rtype = primitiveType(parts[1].charAt(0));
-        Class<?>[] ptypes = new Class<?>[parameters.length()];
-        for (int i = 0; i < ptypes.length; i++) {
-            ptypes[i] = primitiveType(parameters.charAt(i));
+        Class<?> rtype = simpleType(parts[1].charAt(0));
+        if (parameters.isEmpty()) {
+            return MethodType.methodType(rtype);
+        } else {
+            Class<?>[] ptypes = new Class<?>[parameters.length()];
+            for (int i = 0; i < ptypes.length; i++) {
+                ptypes[i] = simpleType(parameters.charAt(i));
+            }
+            return MethodType.methodType(rtype, ptypes);
         }
-        return MethodType.methodType(rtype, ptypes);
     }
 
-    private static Class<?> primitiveType(char c) {
+    private static Class<?> simpleType(char c) {
         switch (c) {
             case 'F':
                 return float.class;
--- a/jdk/test/java/lang/StackWalker/VerifyStackTrace.java	Thu Aug 18 09:52:43 2016 -0700
+++ b/jdk/test/java/lang/StackWalker/VerifyStackTrace.java	Thu Aug 18 19:00:39 2016 +0200
@@ -205,8 +205,12 @@
                     .replaceAll("java.base@(\\d+\\.){0,3}(\\d+)/", "java.base/")
                     .replaceAll("/[0-9]+\\.run", "/xxxxxxxx.run")
                     .replaceAll("/[0-9]+\\.invoke", "/xxxxxxxx.invoke")
+                    // DMHs may or may not be pre-generated, making frames differ
                     .replaceAll("DirectMethodHandle\\$Holder", "LambdaForm\\$DMH")
                     .replaceAll("DMH\\.invoke", "DMH/xxxxxxxx.invoke")
+                    // invoke frames may or may not have basic method type
+                    // information encoded for diagnostic purposes
+                    .replaceAll("xx\\.invoke([A-Za-z]*)_[A-Z]+_[A-Z]", "xx.invoke$1")
                     .replaceAll("\\$[0-9]+", "\\$??");
         } else {
             return produced;