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[java-decompiler] dead code

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This commit is contained in:
Roman Shevchenko
2016-04-20 12:35:17 +02:00
parent 1ac2304d60
commit 77dc5c5f1e
1 changed files with 4 additions and 101 deletions
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103
src/org/jetbrains/java/decompiler/modules/decompiler/ExitHelper.java
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@@ -1,5 +1,5 @@
/*
* Copyright 2000-2015 JetBrains s.r.o.
* Copyright 2000-2016 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.
@@ -21,7 +21,6 @@ import org.jetbrains.java.decompiler.main.collectors.CounterContainer;
import org.jetbrains.java.decompiler.modules.decompiler.exps.ExitExprent;
import org.jetbrains.java.decompiler.modules.decompiler.exps.Exprent;
import org.jetbrains.java.decompiler.modules.decompiler.stats.*;
import org.jetbrains.java.decompiler.struct.gen.MethodDescriptor;
import java.util.ArrayList;
import java.util.Arrays;
@@ -29,32 +28,23 @@ import java.util.List;
import java.util.Set;
public class ExitHelper {
public static boolean condenseExits(RootStatement root) {
int changed = integrateExits(root);
if (changed > 0) {
cleanUpUnreachableBlocks(root);
SequenceHelper.condenseSequences(root);
}
return (changed > 0);
}
private static void cleanUpUnreachableBlocks(Statement stat) {
boolean found;
do {
found = false;
for (int i = 0; i < stat.getStats().size(); i++) {
Statement st = stat.getStats().get(i);
cleanUpUnreachableBlocks(st);
@@ -83,16 +73,12 @@ public class ExitHelper {
while (found);
}
private static int integrateExits(Statement stat) {
int ret = 0;
Statement dest = null;
Statement dest;
if (stat.getExprents() == null) {
while (true) {
int changed = 0;
for (Statement st : stat.getStats()) {
@@ -108,7 +94,6 @@ public class ExitHelper {
}
}
switch (stat.type) {
case Statement.TYPE_IF:
IfStatement ifst = (IfStatement)stat;
@@ -168,15 +153,12 @@ public class ExitHelper {
// LabelHelper.lowContinueLabels(block, new HashSet<StatEdge>());
// do it by hand
for (StatEdge prededge : block.getPredecessorEdges(StatEdge.TYPE_CONTINUE)) {
block.removePredecessor(prededge);
prededge.getSource().changeEdgeNode(Statement.DIRECTION_FORWARD, prededge, stat);
stat.addPredecessor(prededge);
stat.addLabeledEdge(prededge);
}
stat.addSuccessor(new StatEdge(StatEdge.TYPE_REGULAR, stat, bstat));
for (StatEdge edge : dest.getAllPredecessorEdges()) {
@@ -202,11 +184,9 @@ public class ExitHelper {
}
private static Statement isExitEdge(StatEdge edge) {
Statement dest = edge.getDestination();
if (edge.getType() == StatEdge.TYPE_BREAK && dest.type == Statement.TYPE_BASICBLOCK
&& edge.explicit && (edge.labeled || isOnlyEdge(edge))) {
if (edge.getType() == StatEdge.TYPE_BREAK && dest.type == Statement.TYPE_BASICBLOCK && edge.explicit && (edge.labeled || isOnlyEdge(edge))) {
List<Exprent> data = dest.getExprents();
if (data != null && data.size() == 1) {
@@ -220,7 +200,6 @@ public class ExitHelper {
}
private static boolean isOnlyEdge(StatEdge edge) {
Statement stat = edge.getDestination();
for (StatEdge ed : stat.getAllPredecessorEdges()) {
@@ -244,7 +223,6 @@ public class ExitHelper {
}
public static boolean removeRedundantReturns(RootStatement root) {
boolean res = false;
DummyExitStatement dummyExit = root.getDummyExit();
@@ -270,79 +248,4 @@ public class ExitHelper {
return res;
}
public static boolean handleReturnFromInitializer(RootStatement root) {
boolean res = false;
Statement exit = root.getDummyExit();
Statement top = root.getFirst();
Statement newret = null;
boolean sharedcreated = false;
for (StatEdge edge : exit.getAllPredecessorEdges()) {
if (edge.explicit) {
if (!sharedcreated) {
newret = addSharedInitializerReturn(root);
sharedcreated = true;
}
Statement source = edge.getSource();
List<Exprent> lstExpr = source.getExprents();
if (lstExpr != null && !lstExpr.isEmpty()) {
Exprent expr = lstExpr.get(lstExpr.size() - 1);
if (expr.type == Exprent.EXPRENT_EXIT) {
ExitExprent ex = (ExitExprent)expr;
if (ex.getExitType() == ExitExprent.EXIT_RETURN && ex.getValue() == null) {
lstExpr.remove(lstExpr.size() - 1);
source.removeSuccessor(edge);
source.addSuccessor(new StatEdge(StatEdge.TYPE_BREAK, source, newret, top));
res = true;
}
}
}
}
}
return res;
}
private static Statement addSharedInitializerReturn(RootStatement root) {
Statement exit = root.getDummyExit();
Statement top = root.getFirst();
// build a new statement with the single instruction 'return'
BasicBlockStatement bstat = new BasicBlockStatement(new BasicBlock(
DecompilerContext.getCounterContainer().getCounterAndIncrement(CounterContainer.STATEMENT_COUNTER)));
ExitExprent retexpr = new ExitExprent(ExitExprent.EXIT_RETURN, null,
((MethodDescriptor)DecompilerContext
.getProperty(DecompilerContext.CURRENT_METHOD_DESCRIPTOR)).ret, null);
// a changeable list needed
bstat.setExprents(new ArrayList<Exprent>(Arrays.asList(new Exprent[]{retexpr})));
// build sequence to replace the former top statement
SequenceStatement seq = new SequenceStatement(Arrays.asList(top, bstat));
top.setParent(seq);
bstat.setParent(seq);
seq.setParent(root);
root.getStats().removeWithKey(top.id);
root.getStats().addWithKeyAndIndex(0, seq, seq.id);
root.setFirst(seq);
for (StatEdge succedge : top.getAllSuccessorEdges()) {
top.removeSuccessor(succedge);
}
top.addSuccessor(new StatEdge(StatEdge.TYPE_REGULAR, top, bstat));
bstat.addSuccessor(new StatEdge(StatEdge.TYPE_BREAK, bstat, exit, seq));
return bstat;
}
}