From e7598d434005e4482aa9d0ac68feb453677e02be Mon Sep 17 00:00:00 2001
From: Skylot <skylot@gmail.com>
Date: Thu, 3 Dec 2020 18:28:25 +0000
Subject: [PATCH] fix: don't add region on exit block (#1040)

---
 .../dex/visitors/regions/RegionMaker.java     | 26 ++++++++++++
 .../trycatch/TestLoopInTryCatch.java          | 29 +++++++++++++
 .../smali/trycatch/TestLoopInTryCatch.smali   | 42 +++++++++++++++++++
 3 files changed, 97 insertions(+)
 create mode 100644 jadx-core/src/test/java/jadx/tests/integration/trycatch/TestLoopInTryCatch.java
 create mode 100644 jadx-core/src/test/smali/trycatch/TestLoopInTryCatch.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 1e6eae740..0110311b9 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
@@ -30,6 +30,7 @@ import jadx.core.dex.nodes.Edge;
 import jadx.core.dex.nodes.IBlock;
 import jadx.core.dex.nodes.IContainer;
 import jadx.core.dex.nodes.IRegion;
+import jadx.core.dex.nodes.InsnContainer;
 import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.dex.regions.Region;
@@ -76,6 +77,10 @@ public class RegionMaker {
 		if (startBlock == null) {
 			return r;
 		}
+		if (stack.containsExit(startBlock)) {
+			insertEdgeInsns(r, startBlock);
+			return r;
+		}
 
 		int startBlockId = startBlock.getId();
 		if (processedBlocks.get(startBlockId)) {
@@ -95,6 +100,27 @@ public class RegionMaker {
 		return r;
 	}
 
+	private void insertEdgeInsns(Region region, BlockNode exitBlock) {
+		List<EdgeInsnAttr> edgeInsns = exitBlock.getAll(AType.EDGE_INSN);
+		if (edgeInsns.isEmpty()) {
+			return;
+		}
+		List<InsnNode> insns = new ArrayList<>(edgeInsns.size());
+		addOneInsnOfType(insns, edgeInsns, InsnType.BREAK);
+		addOneInsnOfType(insns, edgeInsns, InsnType.CONTINUE);
+		region.add(new InsnContainer(insns));
+	}
+
+	private void addOneInsnOfType(List<InsnNode> insns, List<EdgeInsnAttr> edgeInsns, InsnType insnType) {
+		for (EdgeInsnAttr edgeInsn : edgeInsns) {
+			InsnNode insn = edgeInsn.getInsn();
+			if (insn.getType() == insnType) {
+				insns.add(insn);
+				return;
+			}
+		}
+	}
+
 	/**
 	 * Recursively traverse all blocks from 'block' until block from 'exits'
 	 */
diff --git a/jadx-core/src/test/java/jadx/tests/integration/trycatch/TestLoopInTryCatch.java b/jadx-core/src/test/java/jadx/tests/integration/trycatch/TestLoopInTryCatch.java
new file mode 100644
index 000000000..cd17c91c6
--- /dev/null
+++ b/jadx-core/src/test/java/jadx/tests/integration/trycatch/TestLoopInTryCatch.java
@@ -0,0 +1,29 @@
+package jadx.tests.integration.trycatch;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.tests.api.SmaliTest;
+
+import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
+
+public class TestLoopInTryCatch extends SmaliTest {
+	@Test
+	public void test() {
+		assertThat(getClassNodeFromSmali())
+				.code()
+				.containsLines(2,
+						"int i;",
+						"while (true) {",
+						"    try {",
+						"        i = getI();",
+						"    } catch (RuntimeException unused) {",
+						"        return;",
+						"    }",
+						"    if (i == 1 || i == 2) {",
+						"        break;",
+						"    }",
+						"}",
+						"if (i == 1) {",
+						"}");
+	}
+}
diff --git a/jadx-core/src/test/smali/trycatch/TestLoopInTryCatch.smali b/jadx-core/src/test/smali/trycatch/TestLoopInTryCatch.smali
new file mode 100644
index 000000000..132155ba7
--- /dev/null
+++ b/jadx-core/src/test/smali/trycatch/TestLoopInTryCatch.smali
@@ -0,0 +1,42 @@
+.class public Ltrycatch/TestLoopInTryCatch;
+.super Ljava/lang/Object;
+.source "SourceFile"
+
+.method public static test()V
+    .registers 6
+
+    :try_start
+
+    :loop
+
+    invoke-static {}, Ltrycatch/TestLoopInTryCatch;->getI()I
+    move-result v1
+
+    const/4 v2, 0x1
+
+    if-eq v1, v2, :cond
+
+    const/4 v3, 0x2
+
+    if-eq v1, v3, :cond
+
+    goto :loop
+
+    :cond
+    if-eq v1, v2, :end
+
+    return-void
+
+    :try_end
+    .catch Ljava/lang/RuntimeException; {:try_start .. :try_end} :end
+
+    :end
+    return-void
+.end method
+
+.method public static getI()I
+    .locals 2
+
+    const/4 v1, 0x1
+    return v1
+.end method