org.jetbrains.kotlin.codegen.inline.MaxLocalsCalculator Maven / Gradle / Ivy
/*
* Copyright 2010-2015 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jetbrains.kotlin.codegen.inline;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.org.objectweb.asm.Label;
import org.jetbrains.org.objectweb.asm.MethodVisitor;
import org.jetbrains.org.objectweb.asm.Opcodes;
import org.jetbrains.org.objectweb.asm.Type;
public class MaxLocalsCalculator extends MethodVisitor {
private int maxLocals;
public MaxLocalsCalculator(int api, int access, String descriptor, MethodVisitor mv) {
super(api, mv);
// updates maxLocals
int size = Type.getArgumentsAndReturnSizes(descriptor) >> 2;
if ((access & Opcodes.ACC_STATIC) != 0) {
--size;
}
maxLocals = size;
}
@Override
public void visitVarInsn(int opcode, int var) {
int n;
if (opcode == Opcodes.LLOAD || opcode == Opcodes.DLOAD ||
opcode == Opcodes.LSTORE || opcode == Opcodes.DSTORE) {
n = var + 2;
}
else {
n = var + 1;
}
updateMaxLocals(n);
super.visitVarInsn(opcode, var);
}
@Override
public void visitIincInsn(int var, int increment) {
updateMaxLocals(var + 1);
super.visitIincInsn(var, increment);
}
@Override
public void visitLocalVariable(
@NotNull String name, @NotNull String desc, String signature, @NotNull Label start, @NotNull Label end, int index
) {
// updates max locals
char c = desc.charAt(0);
int n = index + (c == 'J' || c == 'D' ? 2 : 1);
updateMaxLocals(n);
super.visitLocalVariable(name, desc, signature, start, end, index);
}
@Override
public void visitMaxs(int maxStack, int maxLocals) {
super.visitMaxs(maxStack, this.maxLocals);
}
public int getMaxLocals() {
return maxLocals;
}
private void updateMaxLocals(int nextFreeSlotNumber) {
if (nextFreeSlotNumber > maxLocals) {
maxLocals = nextFreeSlotNumber;
}
}
}