MethodHandleBuilder bug?

[Paul Sandoz]

Try with the patch below.

I ain’t tested this throughly.

Paul.

diff -r 4d1e8489a000 src/java.base/share/classes/jdk/experimental/bytecode/BasicTypeHelper.java
--- a/src/java.base/share/classes/jdk/experimental/bytecode/BasicTypeHelper.java	Thu Apr 12 09:26:53 2018 -0400
+++ b/src/java.base/share/classes/jdk/experimental/bytecode/BasicTypeHelper.java	Thu Apr 12 14:22:51 2018 -0700
@@ -73,6 +73,9 @@
             case 'V':
                 return TypeTag.V;
             default:
+                if (s == nullType()) {
+                    return TypeTag.A;
+                }
                 throw new IllegalStateException("Bad type: " + s);
         }
     }
diff -r 4d1e8489a000 src/java.base/share/classes/jdk/experimental/bytecode/TypedCodeBuilder.java
--- a/src/java.base/share/classes/jdk/experimental/bytecode/TypedCodeBuilder.java	Thu Apr 12 09:26:53 2018 -0400
+++ b/src/java.base/share/classes/jdk/experimental/bytecode/TypedCodeBuilder.java	Thu Apr 12 14:22:51 2018 -0700
@@ -238,6 +238,7 @@
         State(ArrayList<T> stack, Vector<T> locals) {
             this.stack = stack;
             this.locals = locals;
+            this.alive = true;
         }
 
         State() {

> On Apr 12, 2018, at 1:23 PM, Paul Sandoz <paul.sandoz at oracle.com> wrote:
> 
> Thanks, i think there is a bug processing the label when merging stack state from which to generate a stack map entry. Something to do with liveness… i might be able to work it out more fully... but i am not too familiar with stack map entries.
> 
> Paul.
> 
>> On Apr 12, 2018, at 7:37 AM, Roland Westrelin <rwestrel at redhat.com> wrote:
>> 
>> 
>> I noticed that this:
>> 
>>   private static final MethodHandle mergeNull = MethodHandleBuilder.loadCode(MethodHandles.lookup(),
>>       "mergeNull",
>>       MethodType.methodType(void.class, TestLWorld.class, boolean.class),
>>       CODE -> {
>>           CODE.
>>           iload_1().
>>           iconst_0().
>>           ifcmp(TypeTag.I, CondKind.EQ, "null").
>>           aload_0().
>>           getfield(TestLWorld.class, "valueField1", "Lcompiler/valhalla/valuetypes/MyValue1;").
>>           goto_("continue").
>>           label("null").
>>           aconst_null().
>>           label("continue").
>>           aload_0().
>>           swap().
>>           putfield(TestLWorld.class, "valueField1", "Lcompiler/valhalla/valuetypes/MyValue1;").
>>           return_();
>>       }
>>       );
>> 
>> works fine but if I swap the code in the if branches:
>> 
>>   private static final MethodHandle mergeNull = MethodHandleBuilder.loadCode(MethodHandles.lookup(),
>>       "mergeNull",
>>       MethodType.methodType(void.class, TestLWorld.class, boolean.class),
>>       CODE -> {
>>           CODE.
>>           iload_1().
>>           iconst_0().
>>           ifcmp(TypeTag.I, CondKind.EQ, "null").
>>           aconst_null().
>>           goto_("continue").
>>           label("null").
>>           aload_0().
>>           getfield(TestLWorld.class, "valueField1", "Lcompiler/valhalla/valuetypes/MyValue1;").
>>           label("continue").
>>           aload_0().
>>           swap().
>>           putfield(TestLWorld.class, "valueField1", "Lcompiler/valhalla/valuetypes/MyValue1;").
>>           return_();
>>       }
>>       );
>> 
>> then I get:
>> 
>> java.lang.ExceptionInInitializerError
>>       at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>       at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
>>       at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
>>       at java.base/java.lang.reflect.Method.invoke(Method.java:564)
>>       at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
>>       at java.base/java.lang.Thread.run(Thread.java:841)
>> Caused by: java.lang.IllegalStateException: Bad type: <null>
>>       at java.base/jdk.experimental.bytecode.BasicTypeHelper.tag(BasicTypeHelper.java:76)
>>       at java.base/jdk.experimental.value.MethodHandleBuilder$IsolatedMethodBuilder$IsolatedMethodTypeHelper.tag(MethodHandleBuilder.java:196)
>>       at java.base/jdk.experimental.value.MethodHandleBuilder$IsolatedMethodBuilder$IsolatedMethodTypeHelper.tag(MethodHandleBuilder.java:138)
>>       at java.base/jdk.experimental.bytecode.CodeBuilder.writeStackMapType(CodeBuilder.java:1257)
>>       at java.base/jdk.experimental.bytecode.CodeBuilder.sameLocals1StackItemFrame(CodeBuilder.java:1305)
>>       at java.base/jdk.experimental.bytecode.TypedCodeBuilder.writeStackMapFrame(TypedCodeBuilder.java:1231)
>>       at java.base/jdk.experimental.bytecode.TypedCodeBuilder.emitStackMap(TypedCodeBuilder.java:1196)
>>       at java.base/jdk.experimental.bytecode.TypedCodeBuilder.resolveJumps(TypedCodeBuilder.java:1189)
>>       at java.base/jdk.experimental.bytecode.MacroCodeBuilder.label(MacroCodeBuilder.java:437)
>>       at compiler.valhalla.valuetypes.TestLWorld.lambda$static$3(TestLWorld.java:505)
>>       at java.base/jdk.experimental.bytecode.MethodBuilder.withCode(MethodBuilder.java:50)
>>       at java.base/jdk.experimental.value.MethodHandleBuilder.lambda$loadCode$1(MethodHandleBuilder.java:101)
>>       at java.base/jdk.experimental.bytecode.ClassBuilder.withMethod(ClassBuilder.java:204)
>>       at java.base/jdk.experimental.value.MethodHandleBuilder.loadCode(MethodHandleBuilder.java:99)
>>       at java.base/jdk.experimental.value.MethodHandleBuilder.loadCode(MethodHandleBuilder.java:77)
>>       at java.base/jdk.experimental.value.MethodHandleBuilder.loadCode(MethodHandleBuilder.java:72)
>>       at compiler.valhalla.valuetypes.TestLWorld.<clinit>(TestLWorld.java:492)
>>       ... 6 more
>> 
>> Roland.
>