From 3f25f072c63ef13178c79f2f5819e82629120738 Mon Sep 17 00:00:00 2001
From: Jonas Konrad <me@yawk.at>
Date: Thu, 3 Dec 2020 15:15:49 +0100
Subject: [PATCH] fix: properly traverse methods with synchronize blocks that
 have no clear exit (PR #1041)

---
 .../dex/visitors/regions/RegionMaker.java     |  2 +
 .../loops/TestSynchronizedInEndlessLoop.java  |  2 -
 .../synchronize/TestSynchronized5.java        | 20 ++++++
 .../smali/synchronize/TestSynchronized5.smali | 62 +++++++++++++++++++
 4 files changed, 84 insertions(+), 2 deletions(-)
 create mode 100644 jadx-core/src/test/java/jadx/tests/integration/synchronize/TestSynchronized5.java
 create mode 100644 jadx-core/src/test/smali/synchronize/TestSynchronized5.smali

diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMaker.java b/jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMaker.java
index b937cc33..0622d212 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMaker.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMaker.java
@@ -594,6 +594,8 @@ public class RegionMaker {
 				List<BlockNode> list = BlockUtils.buildSimplePath(exitBlock);
 				if (list.isEmpty() || !list.get(list.size() - 1).getSuccessors().isEmpty()) {
 					stack.addExit(exitBlock);
+					// we can still try using this as an exit block to make sure it's visited.
+					exit = exitBlock;
 				}
 			}
 		}
diff --git a/jadx-core/src/test/java/jadx/tests/integration/loops/TestSynchronizedInEndlessLoop.java b/jadx-core/src/test/java/jadx/tests/integration/loops/TestSynchronizedInEndlessLoop.java
index 0c574aaf..13f9c760 100644
--- a/jadx-core/src/test/java/jadx/tests/integration/loops/TestSynchronizedInEndlessLoop.java
+++ b/jadx-core/src/test/java/jadx/tests/integration/loops/TestSynchronizedInEndlessLoop.java
@@ -2,7 +2,6 @@ package jadx.tests.integration.loops;
 
 import org.junit.jupiter.api.Test;
 
-import jadx.NotYetImplemented;
 import jadx.core.dex.nodes.ClassNode;
 import jadx.tests.api.IntegrationTest;
 
@@ -34,7 +33,6 @@ public class TestSynchronizedInEndlessLoop extends IntegrationTest {
 	}
 
 	@Test
-	@NotYetImplemented
 	public void test() {
 		ClassNode cls = getClassNode(TestCls.class);
 		String code = cls.getCode().toString();
diff --git a/jadx-core/src/test/java/jadx/tests/integration/synchronize/TestSynchronized5.java b/jadx-core/src/test/java/jadx/tests/integration/synchronize/TestSynchronized5.java
new file mode 100644
index 00000000..2a918bcb
--- /dev/null
+++ b/jadx-core/src/test/java/jadx/tests/integration/synchronize/TestSynchronized5.java
@@ -0,0 +1,20 @@
+package jadx.tests.integration.synchronize;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.SmaliTest;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class TestSynchronized5 extends SmaliTest {
+	@Test
+	public void test() {
+		ClassNode cls = getClassNodeFromSmali();
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsString("1 != 0"));
+		assertThat(code, containsString("System.gc();"));
+	}
+}
diff --git a/jadx-core/src/test/smali/synchronize/TestSynchronized5.smali b/jadx-core/src/test/smali/synchronize/TestSynchronized5.smali
new file mode 100644
index 00000000..cdc2056f
--- /dev/null
+++ b/jadx-core/src/test/smali/synchronize/TestSynchronized5.smali
@@ -0,0 +1,62 @@
+.class public Lsynchronize/TestSynchronized5;
+.super Ljava/lang/Object;
+
+.method public final get()V
+    .registers 6
+
+    monitor-enter p0
+
+    :try_start_1
+
+    const/4 v0, 0
+
+    if-eqz v0, :cond_1
+
+    monitor-exit p0
+
+    return-void
+
+    :cond_1
+
+    monitor-exit p0
+    :try_end_1
+    .catchall {:try_start_1 .. :try_end_1} :catchall_1
+
+    monitor-enter p0
+
+    :try_start_2
+
+    const/4 v1, 1
+
+    if-eqz v1, :cond_2
+
+    invoke-static {}, Ljava/lang/System;->gc()V
+
+    :cond_2
+
+    monitor-exit p0
+    :try_end_2
+    .catchall {:try_start_2 .. :try_end_2} :catchall_2
+
+    return-void
+
+    :catchall_2
+    move-exception v0
+
+    :try_start_3
+    monitor-exit p0
+    :try_end_3
+    .catchall {:try_start_3 .. :try_end_3} :catchall_2
+
+    throw v0
+
+    :catchall_1
+    move-exception v0
+
+    :try_start_4
+    monitor-exit p0
+    :try_end_4
+    .catchall {:try_start_4 .. :try_end_4} :catchall_1
+
+    throw v0
+.end method
-- 
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