com.oracle.svm.hosted.phases

Class IntrinsifyMethodHandlesInvocationPlugin

java.lang.Object

com.oracle.svm.hosted.phases.IntrinsifyMethodHandlesInvocationPlugin

All Implemented Interfaces:

org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderPlugin, org.graalvm.compiler.nodes.graphbuilderconf.NodePlugin

public class IntrinsifyMethodHandlesInvocationPlugin
extends Object
implements org.graalvm.compiler.nodes.graphbuilderconf.NodePlugin

Support for method handles that can be reduced to a plain invocation. This is enough to support the method handles used for Java 8 Lambda expressions. Support for arbitrary method handles is not possible in the Substrate VM, for the same reasons that we cannot support arbitrary reflection.

Design decisions for this phase: So support static analysis, the method handle invocation needs to be replaced with a regular invocation before static analysis runs. This requires inlining of all method that are involved in the method handle dispatch. We introduce the restriction that one method handle invocation can be reduced by exactly one regular invocation, so that we can inherit the bci of that invocation, and there are no nested frame states created for the inlining. The static analysis results are therefore registered using this bci, and the bci is still unique and belongs to the original method.

Implementation: The starting point is an invoke that has a Constant MethodHandle as an argument. The method handle is the appendix of the invokedynamic bytecode generated by javac for lambda expressions. We inline recursively all methods that get the method handle parameter, with special treatment of the invocation methods of the method handle chain provided by MethodHandleAccessProvider. After all inlining (which is done during parsing, configured by the MethodHandlesInlineInvokePlugin), we require to have just a single invocation left. This invocation replaces the original invoke that was our starting point. If we have more than a single invocation left, we fail and report it as an unsupported feature of Substrate VM.

The parsing is done using the original universe and providers of the HotSpot VM. This has a couple of advantages: Our analysis universe is not polluted with types and methods just used for method handles; we can use the constant folding and graph builder plugins of the HotSpot VM; and we can use the MethodHandlePlugin of the HotSpot VM without the need for any wrappers. The downside is that we have to convert types, methods, and constants between our world and the HotSpot world.

Constructor Summary

Constructors

Constructor and Description
IntrinsifyMethodHandlesInvocationPlugin(org.graalvm.compiler.phases.util.Providers providers, com.oracle.graal.pointsto.meta.AnalysisUniverse aUniverse, HostedUniverse hUniverse)

Method Summary

Modifier and Type	Method and Description
boolean	handleInvoke(org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderContext b, jdk.vm.ci.meta.ResolvedJavaMethod method, org.graalvm.compiler.nodes.ValueNode[] args)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.graalvm.compiler.nodes.graphbuilderconf.NodePlugin

canChangeStackKind, handleCheckCast, handleInstanceOf, handleLoadField, handleLoadIndexed, handleLoadStaticField, handleNewArray, handleNewInstance, handleNewMultiArray, handleStoreField, handleStoreIndexed, handleStoreStaticField, instrumentExceptionDispatch

Constructor Detail

IntrinsifyMethodHandlesInvocationPlugin

public IntrinsifyMethodHandlesInvocationPlugin(org.graalvm.compiler.phases.util.Providers providers,
                                               com.oracle.graal.pointsto.meta.AnalysisUniverse aUniverse,
                                               HostedUniverse hUniverse)

Method Detail

handleInvoke

public boolean handleInvoke(org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderContext b,
                            jdk.vm.ci.meta.ResolvedJavaMethod method,
                            org.graalvm.compiler.nodes.ValueNode[] args)

Specified by:

handleInvoke in interface org.graalvm.compiler.nodes.graphbuilderconf.NodePlugin