src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.serviceprovider/src/org/graalvm/compiler/serviceprovider/GraalServices.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2016, 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
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */


 package org.graalvm.compiler.serviceprovider;

 import static java.lang.Thread.currentThread;

 import java.io.IOException;
 import java.io.InputStream;
 import java.lang.reflect.Method;
 import java.util.Iterator;
 import java.util.List;
 import java.util.ServiceConfigurationError;
 import java.util.ServiceLoader;
 import java.util.concurrent.atomic.AtomicLong;

 import jdk.vm.ci.meta.ConstantPool;
 import jdk.vm.ci.meta.JavaType;
 import jdk.vm.ci.services.JVMCIPermission;
 import jdk.vm.ci.services.Services;

 /**
  * Interface to functionality that abstracts over which JDK version Graal is running on.
  */
 public final class GraalServices {

     private static int getJavaSpecificationVersion() {
         String value = System.getProperty("java.specification.version");
         if (value.startsWith("1.")) {
             value = value.substring(2);
         }
         return Integer.parseInt(value);
     }

     /**
      * The integer value corresponding to the value of the {@code java.specification.version} system
      * property after any leading {@code "1."} has been stripped.
      */
     public static final int JAVA_SPECIFICATION_VERSION = getJavaSpecificationVersion();

     /**
      * Determines if the Java runtime is version 8 or earlier.
      */
     public static final boolean Java8OrEarlier = JAVA_SPECIFICATION_VERSION <= 8;

     private GraalServices() {
     }

     /**
      * Gets an {@link Iterable} of the providers available for a given service.
      *
      * @throws SecurityException if on JDK8 and a security manager is present and it denies
      *             {@link JVMCIPermission}
      */
     public static <S> Iterable<S> load(Class<S> service) {
         assert !service.getName().startsWith("jdk.vm.ci") : "JVMCI services must be loaded via " + Services.class.getName();
         Iterable<S> iterable = ServiceLoader.load(service);
         return new Iterable<>() {
             @Override
             public Iterator<S> iterator() {
                 Iterator<S> iterator = iterable.iterator();
                 return new Iterator<>() {
                     @Override
                     public boolean hasNext() {
                         return iterator.hasNext();
                     }

                     @Override
                     public S next() {
                         S provider = iterator.next();
                         // Allow Graal extensions to access JVMCI
                         openJVMCITo(provider.getClass());
                         return provider;
                     }

                     @Override
                     public void remove() {
                         iterator.remove();
                     }
                 };
             }
         };
     }

     /**
      * Opens all JVMCI packages to the module of a given class. This relies on JVMCI already having
      * opened all its packages to the module defining {@link GraalServices}.
      *
      * @param other all JVMCI packages will be opened to the module defining this class
      */
     static void openJVMCITo(Class<?> other) {
         Module jvmciModule = JVMCI_MODULE;
         Module otherModule = other.getModule();
         if (jvmciModule != otherModule) {
             for (String pkg : jvmciModule.getPackages()) {
                 if (!jvmciModule.isOpen(pkg, otherModule)) {
                     jvmciModule.addOpens(pkg, otherModule);
                 }
             }
         }
     }

     /**
      * Gets the provider for a given service for which at most one provider must be available.
      *
      * @param service the service whose provider is being requested
      * @param required specifies if an {@link InternalError} should be thrown if no provider of
      *            {@code service} is available
      * @return the requested provider if available else {@code null}
      * @throws SecurityException if on JDK8 and a security manager is present and it denies
      *             {@link JVMCIPermission}
      */
     public static <S> S loadSingle(Class<S> service, boolean required) {
         assert !service.getName().startsWith("jdk.vm.ci") : "JVMCI services must be loaded via " + Services.class.getName();
         Iterable<S> providers = load(service);
         S singleProvider = null;
         try {
             for (Iterator<S> it = providers.iterator(); it.hasNext();) {
                 singleProvider = it.next();
                 if (it.hasNext()) {
                     S other = it.next();
                     throw new InternalError(String.format("Multiple %s providers found: %s, %s", service.getName(), singleProvider.getClass().getName(), other.getClass().getName()));
                 }
             }
         } catch (ServiceConfigurationError e) {
             // If the service is required we will bail out below.
         }
         if (singleProvider == null) {
             if (required) {
                 throw new InternalError(String.format("No provider for %s found", service.getName()));
             }
         }
         return singleProvider;
     }

     /**
      * Gets the class file bytes for {@code c}.
      */
     public static InputStream getClassfileAsStream(Class<?> c) throws IOException {
         String classfilePath = c.getName().replace('.', '/') + ".class";
         return c.getModule().getResourceAsStream(classfilePath);
     }

     private static final Module JVMCI_MODULE = Services.class.getModule();

     /**
      * A JVMCI package dynamically exported to trusted modules.
      */
     private static final String JVMCI_RUNTIME_PACKAGE = "jdk.vm.ci.runtime";
     static {
         assert JVMCI_MODULE.getPackages().contains(JVMCI_RUNTIME_PACKAGE);
     }

     /**
      * Determines if invoking {@link Object#toString()} on an instance of {@code c} will only run
      * trusted code.
      */
     public static boolean isToStringTrusted(Class<?> c) {
         Module module = c.getModule();
         Module jvmciModule = JVMCI_MODULE;
         assert jvmciModule.getPackages().contains("jdk.vm.ci.runtime");
         if (module == jvmciModule || jvmciModule.isOpen(JVMCI_RUNTIME_PACKAGE, module)) {
             // Can access non-statically-exported package in JVMCI
             return true;
         }
         return false;
     }

     /**
      * Gets a unique identifier for this execution such as a process ID or a
      * {@linkplain #getGlobalTimeStamp() fixed timestamp}.
      */
     public static String getExecutionID() {
         return Long.toString(ProcessHandle.current().pid());
     }

     private static final AtomicLong globalTimeStamp = new AtomicLong();

     /**
      * Gets a time stamp for the current process. This method will always return the same value for
      * the current VM execution.
      */
     public static long getGlobalTimeStamp() {
         if (globalTimeStamp.get() == 0) {
             globalTimeStamp.compareAndSet(0, System.currentTimeMillis());
         }
         return globalTimeStamp.get();
     }

     /**
      * Access to thread specific information made available via Java Management Extensions (JMX).
      * Using this abstraction enables avoiding a dependency to the {@code java.management} and
      * {@code jdk.management} modules on JDK 9 and later.
      */
     public abstract static class JMXService {
         protected abstract long getThreadAllocatedBytes(long id);

         protected abstract long getCurrentThreadCpuTime();

         protected abstract boolean isThreadAllocatedMemorySupported();

         protected abstract boolean isCurrentThreadCpuTimeSupported();

         protected abstract List<String> getInputArguments();

         // Placing this static field in JMXService (instead of GraalServices)
         // allows for lazy initialization.
         static final JMXService instance = loadSingle(JMXService.class, false);
     }

     /**
      * Returns an approximation of the total amount of memory, in bytes, allocated in heap memory
      * for the thread of the specified ID. The returned value is an approximation because some Java
      * virtual machine implementations may use object allocation mechanisms that result in a delay
      * between the time an object is allocated and the time its size is recorded.
      * <p>
      * If the thread of the specified ID is not alive or does not exist, this method returns
      * {@code -1}. If thread memory allocation measurement is disabled, this method returns
      * {@code -1}. A thread is alive if it has been started and has not yet died.
      * <p>
      * If thread memory allocation measurement is enabled after the thread has started, the Java
      * virtual machine implementation may choose any time up to and including the time that the
      * capability is enabled as the point where thread memory allocation measurement starts.
      *
      * @param id the thread ID of a thread
      * @return an approximation of the total memory allocated, in bytes, in heap memory for a thread
      *         of the specified ID if the thread of the specified ID exists, the thread is alive,
      *         and thread memory allocation measurement is enabled; {@code -1} otherwise.
      *
      * @throws IllegalArgumentException if {@code id} {@code <=} {@code 0}.
      * @throws UnsupportedOperationException if the Java virtual machine implementation does not
      *             {@linkplain #isThreadAllocatedMemorySupported() support} thread memory allocation
      *             measurement.
      */
     public static long getThreadAllocatedBytes(long id) {
         JMXService jmx = JMXService.instance;
         if (jmx == null) {
             throw new UnsupportedOperationException();
         }
         return jmx.getThreadAllocatedBytes(id);
     }

     /**
      * Convenience method for calling {@link #getThreadAllocatedBytes(long)} with the id of the
      * current thread.
      */
     public static long getCurrentThreadAllocatedBytes() {
         return getThreadAllocatedBytes(currentThread().getId());
     }

     /**
      * Returns the total CPU time for the current thread in nanoseconds. The returned value is of
      * nanoseconds precision but not necessarily nanoseconds accuracy. If the implementation
      * distinguishes between user mode time and system mode time, the returned CPU time is the
      * amount of time that the current thread has executed in user mode or system mode.
      *
      * @return the total CPU time for the current thread if CPU time measurement is enabled;
      *         {@code -1} otherwise.
      *
      * @throws UnsupportedOperationException if the Java virtual machine does not
      *             {@linkplain #isCurrentThreadCpuTimeSupported() support} CPU time measurement for
      *             the current thread
      */
     public static long getCurrentThreadCpuTime() {
         JMXService jmx = JMXService.instance;
         if (jmx == null) {
             throw new UnsupportedOperationException();
         }
         return jmx.getCurrentThreadCpuTime();
     }

     /**
      * Determines if the Java virtual machine implementation supports thread memory allocation
      * measurement.
      */
     public static boolean isThreadAllocatedMemorySupported() {
         JMXService jmx = JMXService.instance;
         if (jmx == null) {
             return false;
         }
         return jmx.isThreadAllocatedMemorySupported();
     }

     /**
      * Determines if the Java virtual machine supports CPU time measurement for the current thread.
      */
     public static boolean isCurrentThreadCpuTimeSupported() {
         JMXService jmx = JMXService.instance;
         if (jmx == null) {
             return false;
         }
         return jmx.isCurrentThreadCpuTimeSupported();
     }

     /**
      * Gets the input arguments passed to the Java virtual machine which does not include the
      * arguments to the {@code main} method. This method returns an empty list if there is no input
      * argument to the Java virtual machine.
      * <p>
      * Some Java virtual machine implementations may take input arguments from multiple different
      * sources: for examples, arguments passed from the application that launches the Java virtual
      * machine such as the 'java' command, environment variables, configuration files, etc.
      * <p>
      * Typically, not all command-line options to the 'java' command are passed to the Java virtual
      * machine. Thus, the returned input arguments may not include all command-line options.
      *
      * @return the input arguments to the JVM or {@code null} if they are unavailable
      */
     public static List<String> getInputArguments() {
         JMXService jmx = JMXService.instance;
         if (jmx == null) {
             return null;
         }
         return jmx.getInputArguments();
     }

     private static final Method constantPoolLookupReferencedType;

     static {
         Method lookupReferencedType = null;
         Class<?> constantPool = ConstantPool.class;
         try {
             lookupReferencedType = constantPool.getDeclaredMethod("lookupReferencedType", Integer.TYPE, Integer.TYPE);
         } catch (NoSuchMethodException e) {
         }
         constantPoolLookupReferencedType = lookupReferencedType;
     }

     public static JavaType lookupReferencedType(ConstantPool constantPool, int cpi, int opcode) {
         if (constantPoolLookupReferencedType != null) {
             try {
                 return (JavaType) constantPoolLookupReferencedType.invoke(constantPool, cpi, opcode);
             } catch (Error e) {
                 throw e;
             } catch (Throwable throwable) {
                 throw new InternalError(throwable);
             }
         }
         throw new InternalError("This JVMCI version doesn't support ConstantPool.lookupReferencedType()");
     }

     public static boolean hasLookupReferencedType() {
         return constantPoolLookupReferencedType != null;
     }
 }
	/*
	* Copyright (c) 2016, 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
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/


	package org.graalvm.compiler.serviceprovider;

	import static java.lang.Thread.currentThread;

	import java.io.IOException;
	import java.io.InputStream;
	import java.lang.reflect.Method;
	import java.util.Iterator;
	import java.util.List;
	import java.util.ServiceConfigurationError;
	import java.util.ServiceLoader;
	import java.util.concurrent.atomic.AtomicLong;

	import jdk.vm.ci.meta.ConstantPool;
	import jdk.vm.ci.meta.JavaType;
	import jdk.vm.ci.services.JVMCIPermission;
	import jdk.vm.ci.services.Services;

	/**
	* Interface to functionality that abstracts over which JDK version Graal is running on.
	*/
	public final class GraalServices {

	private static int getJavaSpecificationVersion() {
	String value = System.getProperty("java.specification.version");
	if (value.startsWith("1.")) {
	value = value.substring(2);
	}
	return Integer.parseInt(value);
	}

	/**
	* The integer value corresponding to the value of the {@code java.specification.version} system
	* property after any leading {@code "1."} has been stripped.
	*/
	public static final int JAVA_SPECIFICATION_VERSION = getJavaSpecificationVersion();

	/**
	* Determines if the Java runtime is version 8 or earlier.
	*/
	public static final boolean Java8OrEarlier = JAVA_SPECIFICATION_VERSION <= 8;

	private GraalServices() {
	}

	/**
	* Gets an {@link Iterable} of the providers available for a given service.
	*
	* @throws SecurityException if on JDK8 and a security manager is present and it denies
	* {@link JVMCIPermission}
	*/
	public static <S> Iterable<S> load(Class<S> service) {
	assert !service.getName().startsWith("jdk.vm.ci") : "JVMCI services must be loaded via " + Services.class.getName();
	Iterable<S> iterable = ServiceLoader.load(service);
	return new Iterable<>() {
	@Override
	public Iterator<S> iterator() {
	Iterator<S> iterator = iterable.iterator();
	return new Iterator<>() {
	@Override
	public boolean hasNext() {
	return iterator.hasNext();
	}

	@Override
	public S next() {
	S provider = iterator.next();
	// Allow Graal extensions to access JVMCI
	openJVMCITo(provider.getClass());
	return provider;
	}

	@Override
	public void remove() {
	iterator.remove();
	}
	};
	}
	};
	}

	/**
	* Opens all JVMCI packages to the module of a given class. This relies on JVMCI already having
	* opened all its packages to the module defining {@link GraalServices}.
	*
	* @param other all JVMCI packages will be opened to the module defining this class
	*/
	static void openJVMCITo(Class<?> other) {
	Module jvmciModule = JVMCI_MODULE;
	Module otherModule = other.getModule();
	if (jvmciModule != otherModule) {
	for (String pkg : jvmciModule.getPackages()) {
	if (!jvmciModule.isOpen(pkg, otherModule)) {
	jvmciModule.addOpens(pkg, otherModule);
	}
	}
	}
	}

	/**
	* Gets the provider for a given service for which at most one provider must be available.
	*
	* @param service the service whose provider is being requested
	* @param required specifies if an {@link InternalError} should be thrown if no provider of
	* {@code service} is available
	* @return the requested provider if available else {@code null}
	* @throws SecurityException if on JDK8 and a security manager is present and it denies
	* {@link JVMCIPermission}
	*/
	public static <S> S loadSingle(Class<S> service, boolean required) {
	assert !service.getName().startsWith("jdk.vm.ci") : "JVMCI services must be loaded via " + Services.class.getName();
	Iterable<S> providers = load(service);
	S singleProvider = null;
	try {
	for (Iterator<S> it = providers.iterator(); it.hasNext();) {
	singleProvider = it.next();
	if (it.hasNext()) {
	S other = it.next();
	throw new InternalError(String.format("Multiple %s providers found: %s, %s", service.getName(), singleProvider.getClass().getName(), other.getClass().getName()));
	}
	}
	} catch (ServiceConfigurationError e) {
	// If the service is required we will bail out below.
	}
	if (singleProvider == null) {
	if (required) {
	throw new InternalError(String.format("No provider for %s found", service.getName()));
	}
	}
	return singleProvider;
	}

	/**
	* Gets the class file bytes for {@code c}.
	*/
	public static InputStream getClassfileAsStream(Class<?> c) throws IOException {
	String classfilePath = c.getName().replace('.', '/') + ".class";
	return c.getModule().getResourceAsStream(classfilePath);
	}

	private static final Module JVMCI_MODULE = Services.class.getModule();

	/**
	* A JVMCI package dynamically exported to trusted modules.
	*/
	private static final String JVMCI_RUNTIME_PACKAGE = "jdk.vm.ci.runtime";
	static {
	assert JVMCI_MODULE.getPackages().contains(JVMCI_RUNTIME_PACKAGE);
	}

	/**
	* Determines if invoking {@link Object#toString()} on an instance of {@code c} will only run
	* trusted code.
	*/
	public static boolean isToStringTrusted(Class<?> c) {
	Module module = c.getModule();
	Module jvmciModule = JVMCI_MODULE;
	assert jvmciModule.getPackages().contains("jdk.vm.ci.runtime");
	if (module == jvmciModule \|\| jvmciModule.isOpen(JVMCI_RUNTIME_PACKAGE, module)) {
	// Can access non-statically-exported package in JVMCI
	return true;
	}
	return false;
	}

	/**
	* Gets a unique identifier for this execution such as a process ID or a
	* {@linkplain #getGlobalTimeStamp() fixed timestamp}.
	*/
	public static String getExecutionID() {
	return Long.toString(ProcessHandle.current().pid());
	}

	private static final AtomicLong globalTimeStamp = new AtomicLong();

	/**
	* Gets a time stamp for the current process. This method will always return the same value for
	* the current VM execution.
	*/
	public static long getGlobalTimeStamp() {
	if (globalTimeStamp.get() == 0) {
	globalTimeStamp.compareAndSet(0, System.currentTimeMillis());
	}
	return globalTimeStamp.get();
	}

	/**
	* Access to thread specific information made available via Java Management Extensions (JMX).
	* Using this abstraction enables avoiding a dependency to the {@code java.management} and
	* {@code jdk.management} modules on JDK 9 and later.
	*/
	public abstract static class JMXService {
	protected abstract long getThreadAllocatedBytes(long id);

	protected abstract long getCurrentThreadCpuTime();

	protected abstract boolean isThreadAllocatedMemorySupported();

	protected abstract boolean isCurrentThreadCpuTimeSupported();

	protected abstract List<String> getInputArguments();

	// Placing this static field in JMXService (instead of GraalServices)
	// allows for lazy initialization.
	static final JMXService instance = loadSingle(JMXService.class, false);
	}

	/**
	* Returns an approximation of the total amount of memory, in bytes, allocated in heap memory
	* for the thread of the specified ID. The returned value is an approximation because some Java
	* virtual machine implementations may use object allocation mechanisms that result in a delay
	* between the time an object is allocated and the time its size is recorded.
	* <p>
	* If the thread of the specified ID is not alive or does not exist, this method returns
	* {@code -1}. If thread memory allocation measurement is disabled, this method returns
	* {@code -1}. A thread is alive if it has been started and has not yet died.
	* <p>
	* If thread memory allocation measurement is enabled after the thread has started, the Java
	* virtual machine implementation may choose any time up to and including the time that the
	* capability is enabled as the point where thread memory allocation measurement starts.
	*
	* @param id the thread ID of a thread
	* @return an approximation of the total memory allocated, in bytes, in heap memory for a thread
	* of the specified ID if the thread of the specified ID exists, the thread is alive,
	* and thread memory allocation measurement is enabled; {@code -1} otherwise.
	*
	* @throws IllegalArgumentException if {@code id} {@code <=} {@code 0}.
	* @throws UnsupportedOperationException if the Java virtual machine implementation does not
	* {@linkplain #isThreadAllocatedMemorySupported() support} thread memory allocation
	* measurement.
	*/
	public static long getThreadAllocatedBytes(long id) {
	JMXService jmx = JMXService.instance;
	if (jmx == null) {
	throw new UnsupportedOperationException();
	}
	return jmx.getThreadAllocatedBytes(id);
	}

	/**
	* Convenience method for calling {@link #getThreadAllocatedBytes(long)} with the id of the
	* current thread.
	*/
	public static long getCurrentThreadAllocatedBytes() {
	return getThreadAllocatedBytes(currentThread().getId());
	}

	/**
	* Returns the total CPU time for the current thread in nanoseconds. The returned value is of
	* nanoseconds precision but not necessarily nanoseconds accuracy. If the implementation
	* distinguishes between user mode time and system mode time, the returned CPU time is the
	* amount of time that the current thread has executed in user mode or system mode.
	*
	* @return the total CPU time for the current thread if CPU time measurement is enabled;
	* {@code -1} otherwise.
	*
	* @throws UnsupportedOperationException if the Java virtual machine does not
	* {@linkplain #isCurrentThreadCpuTimeSupported() support} CPU time measurement for
	* the current thread
	*/
	public static long getCurrentThreadCpuTime() {
	JMXService jmx = JMXService.instance;
	if (jmx == null) {
	throw new UnsupportedOperationException();
	}
	return jmx.getCurrentThreadCpuTime();
	}

	/**
	* Determines if the Java virtual machine implementation supports thread memory allocation
	* measurement.
	*/
	public static boolean isThreadAllocatedMemorySupported() {
	JMXService jmx = JMXService.instance;
	if (jmx == null) {
	return false;
	}
	return jmx.isThreadAllocatedMemorySupported();
	}

	/**
	* Determines if the Java virtual machine supports CPU time measurement for the current thread.
	*/
	public static boolean isCurrentThreadCpuTimeSupported() {
	JMXService jmx = JMXService.instance;
	if (jmx == null) {
	return false;
	}
	return jmx.isCurrentThreadCpuTimeSupported();
	}

	/**
	* Gets the input arguments passed to the Java virtual machine which does not include the
	* arguments to the {@code main} method. This method returns an empty list if there is no input
	* argument to the Java virtual machine.
	* <p>
	* Some Java virtual machine implementations may take input arguments from multiple different
	* sources: for examples, arguments passed from the application that launches the Java virtual
	* machine such as the 'java' command, environment variables, configuration files, etc.
	* <p>
	* Typically, not all command-line options to the 'java' command are passed to the Java virtual
	* machine. Thus, the returned input arguments may not include all command-line options.
	*
	* @return the input arguments to the JVM or {@code null} if they are unavailable
	*/
	public static List<String> getInputArguments() {
	JMXService jmx = JMXService.instance;
	if (jmx == null) {
	return null;
	}
	return jmx.getInputArguments();
	}

	private static final Method constantPoolLookupReferencedType;

	static {
	Method lookupReferencedType = null;
	Class<?> constantPool = ConstantPool.class;
	try {
	lookupReferencedType = constantPool.getDeclaredMethod("lookupReferencedType", Integer.TYPE, Integer.TYPE);
	} catch (NoSuchMethodException e) {
	}
	constantPoolLookupReferencedType = lookupReferencedType;
	}

	public static JavaType lookupReferencedType(ConstantPool constantPool, int cpi, int opcode) {
	if (constantPoolLookupReferencedType != null) {
	try {
	return (JavaType) constantPoolLookupReferencedType.invoke(constantPool, cpi, opcode);
	} catch (Error e) {
	throw e;
	} catch (Throwable throwable) {
	throw new InternalError(throwable);
	}
	}
	throw new InternalError("This JVMCI version doesn't support ConstantPool.lookupReferencedType()");
	}

	public static boolean hasLookupReferencedType() {
	return constantPoolLookupReferencedType != null;
	}
	}