core: allow to skip sub-blocks for region visitor.

jadx-core/src/main/java/jadx/core/dex/visitors/regions/AbstractRegionVisitor.java

@@ -7,7 +7,8 @@ import jadx.core.dex.nodes.MethodNode;
 public abstract class AbstractRegionVisitor implements IRegionVisitor {
 
 	@Override
-	public void enterRegion(MethodNode mth, IRegion region) {
+	public boolean enterRegion(MethodNode mth, IRegion region) {
+		return true;
 	}
 
 	@Override

jadx-core/src/main/java/jadx/core/dex/visitors/regions/CheckRegions.java

@@ -64,13 +64,14 @@ public class CheckRegions extends AbstractVisitor {
 		// check loop conditions
 		DepthRegionTraversal.traverse(mth, new AbstractRegionVisitor() {
 			@Override
-			public void enterRegion(MethodNode mth, IRegion region) {
+			public boolean enterRegion(MethodNode mth, IRegion region) {
 				if (region instanceof LoopRegion) {
 					BlockNode loopHeader = ((LoopRegion) region).getHeader();
 					if (loopHeader != null && loopHeader.getInstructions().size() != 1) {
 						ErrorsCounter.methodError(mth, "Incorrect condition in loop: " + loopHeader);
 					}
 				}
+				return true;
 			}
 		});
 	}

jadx-core/src/main/java/jadx/core/dex/visitors/regions/CleanRegions.java

@@ -23,9 +23,9 @@ public class CleanRegions {
 		}
 		IRegionVisitor removeEmptyBlocks = new AbstractRegionVisitor() {
 			@Override
-			public void enterRegion(MethodNode mth, IRegion region) {
+			public boolean enterRegion(MethodNode mth, IRegion region) {
 				if (!(region instanceof Region)) {
-					return;
+					return true;
 				}
 
 				for (Iterator<IContainer> it = region.getSubBlocks().iterator(); it.hasNext(); ) {
@@ -42,6 +42,7 @@ public class CleanRegions {
 					}
 
 				}
+				return true;
 			}
 		};
 		DepthRegionTraversal.traverse(mth, removeEmptyBlocks);

jadx-core/src/main/java/jadx/core/dex/visitors/regions/DepthRegionTraversal.java

@@ -53,9 +53,10 @@ public class DepthRegionTraversal {
 			visitor.processBlock(mth, (IBlock) container);
 		} else if (container instanceof IRegion) {
 			IRegion region = (IRegion) container;
-			visitor.enterRegion(mth, region);
-			for (IContainer subCont : region.getSubBlocks()) {
-				traverseInternal(mth, visitor, subCont);
+			if (visitor.enterRegion(mth, region)) {
+				for (IContainer subCont : region.getSubBlocks()) {
+					traverseInternal(mth, visitor, subCont);
+				}
 			}
 			visitor.leaveRegion(mth, region);
 		}

jadx-core/src/main/java/jadx/core/dex/visitors/regions/IRegionVisitor.java

@@ -8,7 +8,10 @@ public interface IRegionVisitor {
 
 	void processBlock(MethodNode mth, IBlock container);
 
-	void enterRegion(MethodNode mth, IRegion region);
+	/**
+	 * @return true for traverse sub-blocks, false otherwise.
+	 */
+	boolean enterRegion(MethodNode mth, IRegion region);
 
 	void leaveRegion(MethodNode mth, IRegion region);
 

jadx-core/src/main/java/jadx/core/dex/visitors/regions/IfRegionVisitor.java

@@ -38,10 +38,11 @@ public class IfRegionVisitor extends AbstractVisitor implements IRegionVisitor,
 	}
 
 	@Override
-	public void enterRegion(MethodNode mth, IRegion region) {
+	public boolean enterRegion(MethodNode mth, IRegion region) {
 		if (region instanceof IfRegion) {
 			processIfRegion(mth, (IfRegion) region);
 		}
+		return true;
 	}
 
 	@Override

jadx-core/src/main/java/jadx/core/dex/visitors/regions/LoopRegionVisitor.java

@@ -47,10 +47,11 @@ public class LoopRegionVisitor extends AbstractVisitor implements IRegionVisitor
 	}
 
 	@Override
-	public void enterRegion(MethodNode mth, IRegion region) {
+	public boolean enterRegion(MethodNode mth, IRegion region) {
 		if (region instanceof LoopRegion) {
 			processLoopRegion(mth, (LoopRegion) region);
 		}
+		return true;
 	}
 
 	private static void processLoopRegion(MethodNode mth, LoopRegion loopRegion) {

jadx-core/src/main/java/jadx/core/dex/visitors/regions/TracedRegionVisitor.java

@@ -12,12 +12,13 @@ public abstract class TracedRegionVisitor implements IRegionVisitor {
 	protected final Deque<IRegion> regionStack = new ArrayDeque<IRegion>();
 
 	@Override
-	public final void enterRegion(MethodNode mth, IRegion region) {
+	public boolean enterRegion(MethodNode mth, IRegion region) {
 		regionStack.push(region);
+		return true;
 	}
 
 	@Override
-	public final void processBlock(MethodNode mth, IBlock container) {
+	public void processBlock(MethodNode mth, IBlock container) {
 		IRegion curRegion = regionStack.peek();
 		processBlockTraced(mth, container, curRegion);
 	}
@@ -25,7 +26,7 @@ public abstract class TracedRegionVisitor implements IRegionVisitor {
 	public abstract void processBlockTraced(MethodNode mth, IBlock container, IRegion currentRegion);
 
 	@Override
-	public final void leaveRegion(MethodNode mth, IRegion region) {
+	public void leaveRegion(MethodNode mth, IRegion region) {
 		regionStack.pop();
 	}
 }