de.unkrig.commons.asm.InsnUtil Maven / Gradle / Ivy
/*
* de.unkrig.commons - A general-purpose Java class library
*
* Copyright (c) 2011, Arno Unkrig
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
* following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
package de.unkrig.commons.asm;
import java.util.List;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.InsnNode;
import org.objectweb.asm.tree.LdcInsnNode;
import org.objectweb.asm.tree.TypeInsnNode;
import de.unkrig.commons.nullanalysis.Nullable;
/**
* A utility class for handling of ASM instruction lists.
*/
public final
class InsnUtil {
private
InsnUtil() {}
/**
* @return An {@link InsnList} with the single instruction {@code ain}.
*/
public static InsnList
il(AbstractInsnNode ain) {
InsnList insns = new InsnList();
insns.add(ain);
return insns;
}
/**
* @return An {@link InsnList} that contains the given instruction nodes.
*/
public static InsnList
il(AbstractInsnNode... ains) {
InsnList insns = new InsnList();
for (AbstractInsnNode ain : ains) {
insns.add(ain);
}
return insns;
}
/**
* @param il {@link InsnList}s that each create exactly one {@link Object} on the operand stack
* @return Code that produces an object array filled with the values produced by the {@code il}s
*/
public static InsnList
oa(InsnList... il) {
InsnList insns = new InsnList();
insns.add(new LdcInsnNode(il.length));
insns.add(new TypeInsnNode(Opcodes.ANEWARRAY, "java/lang/Object"));
for (int i = 0; i < il.length; i++) {
insns.add(new InsnNode(Opcodes.DUP));
insns.add(new LdcInsnNode(i));
insns.add(il[i]);
insns.add(new InsnNode(Opcodes.AASTORE));
}
return insns;
}
/**
* @param insnLists {@link InsnList}s that each create exactly one {@link Object} on the operand stack
* @return Code that produces an object array filled with the values produced by the {@code insnLists}
*/
public static InsnList
oa(List insnLists) {
if (insnLists.isEmpty()) return InsnUtil.il(InsnUtil.push(null));
InsnList insns = new InsnList();
insns.add(InsnUtil.push(insnLists.size()));
insns.add(new TypeInsnNode(Opcodes.ANEWARRAY, "java/lang/Object"));
for (int i = 0; i < insnLists.size(); i++) {
insns.add(new InsnNode(Opcodes.DUP));
insns.add(new LdcInsnNode(i));
insns.add(insnLists.get(i));
insns.add(new InsnNode(Opcodes.AASTORE));
}
return insns;
}
/** @return Code that puts the given constant value on the operand stack */
public static AbstractInsnNode
push(@Nullable Object constantValue) {
return (
constantValue == null
? new InsnNode(Opcodes.ACONST_NULL)
: new LdcInsnNode(constantValue)
);
}
}