org.glassfish.pfl.objectweb.asm.tree.FrameNode Maven / Gradle / Ivy
/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2007 INRIA, France Telecom
* 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. Neither the name of the copyright holders 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.
*/
package org.glassfish.pfl.objectweb.asm.tree;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import org.glassfish.pfl.objectweb.asm.MethodVisitor;
import org.glassfish.pfl.objectweb.asm.Opcodes;
/**
* A node that represents a stack map frame. These nodes are pseudo instruction
* nodes in order to be inserted in an instruction list. In fact these nodes
* must(*) be inserted just before any instruction node i that
* follows an unconditionnal branch instruction such as GOTO or THROW, that is
* the target of a jump instruction, or that starts an exception handler block.
* The stack map frame types must describe the values of the local variables and
* of the operand stack elements just before i is executed.
*
(*) this is mandatory only for classes whose version is greater than or
* equal to {@link Opcodes#V1_6 V1_6}.
*
* @author Eric Bruneton
*/
public class FrameNode extends AbstractInsnNode {
/**
* The type of this frame. Must be {@link Opcodes#F_NEW} for expanded
* frames, or {@link Opcodes#F_FULL}, {@link Opcodes#F_APPEND},
* {@link Opcodes#F_CHOP}, {@link Opcodes#F_SAME} or
* {@link Opcodes#F_APPEND}, {@link Opcodes#F_SAME1} for compressed frames.
*/
public int type;
/**
* The types of the local variables of this stack map frame. Elements of
* this list can be Integer, String or LabelNode objects (for primitive,
* reference and uninitialized types respectively - see
* {@link MethodVisitor}).
*/
public List local;
/**
* The types of the operand stack elements of this stack map frame. Elements
* of this list can be Integer, String or LabelNode objects (for primitive,
* reference and uninitialized types respectively - see
* {@link MethodVisitor}).
*/
public List stack;
private FrameNode() {
super(-1);
}
/**
* Constructs a new {@link FrameNode}.
*
* @param type the type of this frame. Must be {@link Opcodes#F_NEW} for
* expanded frames, or {@link Opcodes#F_FULL},
* {@link Opcodes#F_APPEND}, {@link Opcodes#F_CHOP},
* {@link Opcodes#F_SAME} or {@link Opcodes#F_APPEND},
* {@link Opcodes#F_SAME1} for compressed frames.
* @param nLocal number of local variables of this stack map frame.
* @param local the types of the local variables of this stack map frame.
* Elements of this list can be Integer, String or LabelNode objects
* (for primitive, reference and uninitialized types respectively -
* see {@link MethodVisitor}).
* @param nStack number of operand stack elements of this stack map frame.
* @param stack the types of the operand stack elements of this stack map
* frame. Elements of this list can be Integer, String or LabelNode
* objects (for primitive, reference and uninitialized types
* respectively - see {@link MethodVisitor}).
*/
public FrameNode(
final int type,
final int nLocal,
final Object[] local,
final int nStack,
final Object[] stack)
{
super(-1);
this.type = type;
switch (type) {
case Opcodes.F_NEW:
case Opcodes.F_FULL:
this.local = asList(nLocal, local);
this.stack = asList(nStack, stack);
break;
case Opcodes.F_APPEND:
this.local = asList(nLocal, local);
break;
case Opcodes.F_CHOP:
this.local = Arrays.asList(new Object[nLocal]);
break;
case Opcodes.F_SAME:
break;
case Opcodes.F_SAME1:
this.stack = asList(1, stack);
break;
}
}
public int getType() {
return FRAME;
}
/**
* Makes the given visitor visit this stack map frame.
*
* @param mv a method visitor.
*/
public void accept(final MethodVisitor mv) {
switch (type) {
case Opcodes.F_NEW:
case Opcodes.F_FULL:
mv.visitFrame(type,
local.size(),
asArray(local),
stack.size(),
asArray(stack));
break;
case Opcodes.F_APPEND:
mv.visitFrame(type, local.size(), asArray(local), 0, null);
break;
case Opcodes.F_CHOP:
mv.visitFrame(type, local.size(), null, 0, null);
break;
case Opcodes.F_SAME:
mv.visitFrame(type, 0, null, 0, null);
break;
case Opcodes.F_SAME1:
mv.visitFrame(type, 0, null, 1, asArray(stack));
break;
}
}
public AbstractInsnNode clone(final Map labels) {
FrameNode clone = new FrameNode();
clone.type = type;
if (local != null) {
clone.local = new ArrayList();
for (int i = 0; i < local.size(); ++i) {
Object l = local.get(i);
if (l instanceof LabelNode) {
l = labels.get(l);
}
clone.local.add(l);
}
}
if (stack != null) {
clone.stack = new ArrayList();
for (int i = 0; i < stack.size(); ++i) {
Object s = stack.get(i);
if (s instanceof LabelNode) {
s = labels.get(s);
}
clone.stack.add(s);
}
}
return clone;
}
// ------------------------------------------------------------------------
private static List asList(final int n, final Object[] o) {
return Arrays.asList(o).subList(0, n);
}
private static Object[] asArray(final List l) {
Object[] objs = new Object[l.size()];
for (int i = 0; i < objs.length; ++i) {
Object o = l.get(i);
if (o instanceof LabelNode) {
o = ((LabelNode) o).getLabel();
}
objs[i] = o;
}
return objs;
}
}
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