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Temporary fix to handle loop that won't inline its condition #100

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Merged
LexManos merged 1 commit into from
Jun 2, 2021
Merged

Temporary fix to handle loop that won't inline its condition #100

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96 changes: 96 additions & 0 deletions FernFlower-Patches/0041-Temporary-fix-for-a-loop-inlining-failure.patch
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Original file line number Diff line number Diff line change
@@ -0,0 +1,96 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: zml <zml@stellardrift.ca>
Date: Wed, 26 May 2021 21:48:01 -0700
Subject: [PATCH] Temporary fix for a loop inlining failure

This masks a failure to properly inline conditions in a do {} while();
loop, but allows producing a compilable result for now.

Co-Authored-By: Geolykt <admin@geolykt.de>

diff --git a/src/org/jetbrains/java/decompiler/modules/decompiler/IfHelper.java b/src/org/jetbrains/java/decompiler/modules/decompiler/IfHelper.java
index afcf55e1429a880ca5d945cd127ef90de25daee2..725951ff0d0350720ab0f92601e1db7767d73f2b 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/IfHelper.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/IfHelper.java
@@ -109,7 +109,7 @@ public final class IfHelper {
private static boolean collapseIfIf(IfNode rtnode) {
if (rtnode.edgetypes.get(0) == 0) {
IfNode ifbranch = rtnode.succs.get(0);
- if (ifbranch.succs.size() == 2) {
+ if (ifbranch.succs.size() == 2 && rtnode.succs.size() >= 2) {

// if-if branch
if (ifbranch.succs.get(1).value == rtnode.succs.get(1).value) {
@@ -181,7 +181,7 @@ public final class IfHelper {
private static boolean collapseIfElse(IfNode rtnode) {
if (rtnode.edgetypes.get(0) == 0) {
IfNode ifbranch = rtnode.succs.get(0);
- if (ifbranch.succs.size() == 2) {
+ if (ifbranch.succs.size() == 2 && rtnode.succs.size() >= 2) {
// if-else branch
if (ifbranch.succs.get(0).value == rtnode.succs.get(1).value) {

@@ -230,7 +230,7 @@ public final class IfHelper {
}

private static boolean collapseElse(IfNode rtnode) {
- if (rtnode.edgetypes.get(1) == 0) {
+ if (rtnode.edgetypes.size() >= 2 && rtnode.edgetypes.get(1) == 0) {
IfNode elsebranch = rtnode.succs.get(1);
if (elsebranch.succs.size() == 2) {

@@ -363,7 +363,11 @@ public final class IfHelper {
}

// else branch
- StatEdge edge = stat.getAllSuccessorEdges().get(0);
+ final List<StatEdge> successorEdges = stat.getAllSuccessorEdges();
+ if (successorEdges.isEmpty()) {
+ return res;
+ }
+ StatEdge edge = successorEdges.get(0);
Statement elsechild = edge.getDestination();
IfNode elsenode = new IfNode(elsechild);

@@ -494,7 +498,7 @@ public final class IfHelper {

ifstat.iftype = IfStatement.IFTYPE_IFELSE;
}
- else if (ifdirect && (!elsedirect || (noifstat && !noelsestat))) { // if - then
+ else if (ifdirect && (!elsedirect || (noifstat && !noelsestat)) && !ifstat.getAllSuccessorEdges().isEmpty()) { // if - then

// negate the if condition
IfExprent statexpr = ifstat.getHeadexprent();
diff --git a/src/org/jetbrains/java/decompiler/modules/decompiler/LoopExtractHelper.java b/src/org/jetbrains/java/decompiler/modules/decompiler/LoopExtractHelper.java
index 04b82fc67fca471f6c868c227df24160e57edb5f..4bdc50263e88ec2857661aaae9ef6d21b4add97c 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/LoopExtractHelper.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/LoopExtractHelper.java
@@ -102,9 +102,13 @@ public final class LoopExtractHelper {
IfStatement lastif = (IfStatement)last;
if (lastif.iftype == IfStatement.IFTYPE_IF && lastif.getIfstat() != null) {
Statement ifstat = lastif.getIfstat();
- StatEdge elseedge = lastif.getAllSuccessorEdges().get(0);
+ final List<StatEdge> successorEdges = lastif.getAllSuccessorEdges();
+ if (successorEdges.isEmpty()) {
+ return false;
+ }
+ StatEdge elseedge = successorEdges.get(0);

- if (elseedge.getType() == StatEdge.TYPE_CONTINUE && elseedge.closure == stat) {
+ if (elseedge == null || elseedge.getType() == StatEdge.TYPE_CONTINUE && elseedge.closure == stat) {

Set<Statement> set = stat.getNeighboursSet(StatEdge.TYPE_CONTINUE, Statement.DIRECTION_BACKWARD);
set.remove(last);
diff --git a/src/org/jetbrains/java/decompiler/modules/decompiler/sforms/FlattenStatementsHelper.java b/src/org/jetbrains/java/decompiler/modules/decompiler/sforms/FlattenStatementsHelper.java
index b6754ef09179b8e7028a98248f6bff2b100b94af..3f15c35b5cec992393c52bbfaba023844cd4a94e 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/sforms/FlattenStatementsHelper.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/sforms/FlattenStatementsHelper.java
@@ -283,7 +283,7 @@ public class FlattenStatementsHelper {
node = graph.nodes.getWithKey(mapDestinationNodes.get(stat.getFirst().id)[0]);
mapDestinationNodes.put(stat.id, new String[]{node.id, null});

- if (stat.type == Statement.TYPE_IF && ((IfStatement)stat).iftype == IfStatement.IFTYPE_IF) {
+ if (stat.type == Statement.TYPE_IF && ((IfStatement)stat).iftype == IfStatement.IFTYPE_IF && !stat.getAllSuccessorEdges().isEmpty()) {
lstSuccEdges.add(stat.getSuccessorEdges(Statement.STATEDGE_DIRECT_ALL).get(0)); // exactly one edge
sourcenode = tailexprlst.get(0) == null ? node : graph.nodes.getWithKey(node.id + "_tail");
}