Add removeDeadCode method

master
Graham 5 years ago
parent cf8939a540
commit 70ccdfa526
  1. 35
      asm/src/main/java/dev/openrs2/asm/MethodNodeUtils.java

@ -2,6 +2,7 @@ package dev.openrs2.asm;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.stream.Collectors;
@ -11,8 +12,12 @@ import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.AnnotationNode;
import org.objectweb.asm.tree.FrameNode;
import org.objectweb.asm.tree.IincInsnNode;
import org.objectweb.asm.tree.LabelNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.VarInsnNode;
import org.objectweb.asm.tree.analysis.Analyzer;
import org.objectweb.asm.tree.analysis.AnalyzerException;
import org.objectweb.asm.tree.analysis.BasicInterpreter;
public final class MethodNodeUtils {
private static int localIndex(int access, List<Type> argTypes, int argIndex) {
@ -129,6 +134,36 @@ public final class MethodNodeUtils {
}
}
public static void removeDeadCode(String owner, MethodNode method) throws AnalyzerException {
boolean changed;
do {
changed = false;
var analyzer = new Analyzer<>(new BasicInterpreter());
var frames = analyzer.analyze(owner, method);
var deadLabels = new HashSet<LabelNode>();
var i = 0;
for (var it = method.instructions.iterator(); it.hasNext(); ) {
var insn = it.next();
if (frames[i++] != null) {
continue;
}
if (insn.getType() == AbstractInsnNode.LABEL) {
deadLabels.add((LabelNode) insn);
} else {
it.remove();
changed = true;
}
}
if (method.tryCatchBlocks.removeIf(tryCatch -> deadLabels.contains(tryCatch.start) && deadLabels.contains(tryCatch.end))) {
changed = true;
}
} while (changed);
}
private MethodNodeUtils() {
/* empty */
}

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