/*
* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// Simple sample to demonstrate openjdk asmtools assembler with
// nashorn dynalink linker in a invokedynamic instruction.
//
// To assemble this file, use the following command:
//
// java -cp <asmtools.jar> org.openjdk.asmtools.Main jasm Main.asm
//
// See also: https://wiki.openjdk.java.net/display/CodeTools/asmtools
//
// NOTE: Uses dynalink API defined by JEP-276 (http://openjdk.java.net/jeps/276)
super public class Main
version 52:0
{
private static final Field linker:"Ljdk/dynalink/DynamicLinker;";
/*
static {
// create dynalink linker factory
final DynamicLinkerFactory factory = new DynamicLinkerFactory();
// create standard linker that can handle Java POJOs
linker = factory.createLinker();
}
*/
static Method "<clinit>":"()V"
stack 2 locals 1
{
new class jdk/dynalink/DynamicLinkerFactory;
dup;
invokespecial Method jdk/dynalink/DynamicLinkerFactory."<init>":"()V";
astore_0;
aload_0;
invokevirtual Method jdk/dynalink/DynamicLinkerFactory.createLinker:"()Ljdk/dynalink/DynamicLinker;";
putstatic Field linker:"Ljdk/dynalink/DynamicLinker;";
return;
}
/*
// Bootstrap method used with invokedynamic methods
public static CallSite bootstrap(MethodHandles.Lookup caller, String name, MethodType type) {
// use dynalink linker to perform the actual linking
return linker.link(
new SimpleRelinkableCallSite(
new CallSiteDescriptor(
MethodHandles.publicLookup(),
new NamedOperation(StandardOperation.GET_PROPERTY, name), type)
)
);
}
*/
public static Method bootstrap:"(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;"
stack 10 locals 3
{
getstatic Field linker:"Ljdk/dynalink/DynamicLinker;";
new class jdk/dynalink/support/SimpleRelinkableCallSite;
dup;
new class jdk/dynalink/CallSiteDescriptor;
dup;
invokestatic Method java/lang/invoke/MethodHandles.publicLookup:"()Ljava/lang/invoke/MethodHandles$Lookup;";
new class jdk/dynalink/NamedOperation;
dup;
getstatic Field jdk/dynalink/StandardOperation.GET_PROPERTY:"Ljdk/dynalink/StandardOperation;";
aload_1;
invokespecial Method jdk/dynalink/NamedOperation."<init>":"(Ljdk/dynalink/Operation;Ljava/lang/Object;)V";
aload_2;
invokespecial Method jdk/dynalink/CallSiteDescriptor."<init>":"(Ljava/lang/invoke/MethodHandles$Lookup;Ljdk/dynalink/Operation;Ljava/lang/invoke/MethodType;)V";
invokespecial Method jdk/dynalink/support/SimpleRelinkableCallSite."<init>":"(Ljdk/dynalink/CallSiteDescriptor;)V";
invokevirtual Method jdk/dynalink/DynamicLinker.link:"(Ljdk/dynalink/RelinkableCallSite;)Ljdk/dynalink/RelinkableCallSite;";
checkcast class java/lang/invoke/CallSite;
areturn;
}
// default constructor that does nothing!
public Method "<init>":"()V"
stack 1 locals 1
{
aload_0;
invokespecial Method java/lang/Object."<init>":"()V";
return;
}
public static Method main:"([Ljava/lang/String;)V"
stack 2 locals 2
{
// List l = new ArrayList();
new class java/util/ArrayList;
dup;
invokespecial Method java/util/ArrayList."<init>":"()V";
astore_1;
aload_1;
// l.add("hello");
ldc String "hello";
invokeinterface InterfaceMethod java/util/List.add:"(Ljava/lang/Object;)Z", 2;
pop;
// l.add("world");
aload_1;
ldc String "world";
invokeinterface InterfaceMethod java/util/List.add:"(Ljava/lang/Object;)Z", 2;
pop;
// printLength(l);
aload_1;
invokestatic Method printLength:"(Ljava/lang/Object;)V";
// printLength(args); // args is argument of main method
aload_0;
invokestatic Method printLength:"(Ljava/lang/Object;)V";
return;
}
private static Method printLength:"(Ljava/lang/Object;)V"
stack 2 locals 1
{
getstatic Field java/lang/System.out:"Ljava/io/PrintStream;";
aload_0;
// Using bootstrap method in this class with the following invokedynamic
// which uses dynalink linker. Dynalink's bean linker handles Java beans.
// 'length' property on a bean - arrays, lists supported
invokedynamic InvokeDynamic REF_invokeStatic:Main.bootstrap:"(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;":"length":"(Ljava/lang/Object;)Ljava/lang/Object;";
// print 'length' value
invokevirtual Method java/io/PrintStream.println:"(Ljava/lang/Object;)V";
return;
}
} // end Class Main