fix: resolve some cases of switch in loop (#876)

jadx-core/src/main/java/jadx/core/dex/instructions/SwitchNode.java

@@ -119,14 +119,23 @@ public class SwitchNode extends TargetInsnNode {
 	public String toString() {
 		StringBuilder sb = new StringBuilder();
 		sb.append(super.toString());
-		for (int i = 0; i < targets.length; i++) {
-			sb.append(CodeWriter.NL);
-			sb.append("  case ").append(keys[i]);
-			sb.append(": goto ").append(InsnUtils.formatOffset(targets[i]));
-		}
-		if (def != -1) {
-			sb.append(CodeWriter.NL);
-			sb.append("  default: goto ").append(InsnUtils.formatOffset(def));
+		if (targetBlocks == null) {
+			for (int i = 0; i < keys.length; i++) {
+				sb.append(CodeWriter.NL);
+				sb.append("  case ").append(keys[i]).append(": goto ").append(InsnUtils.formatOffset(targets[i]));
+			}
+			if (def != -1) {
+				sb.append(CodeWriter.NL);
+				sb.append("  default: goto ").append(InsnUtils.formatOffset(def));
+			}
+		} else {
+			for (int i = 0; i < keys.length; i++) {
+				sb.append(CodeWriter.NL);
+				sb.append("  case ").append(keys[i]).append(": goto ").append(targetBlocks[i]);
+			}
+			if (def != -1) {
+				sb.append(CodeWriter.NL).append("  default: goto ").append(defTargetBlock);
+			}
 		}
 		return sb.toString();
 	}

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

@@ -761,14 +761,30 @@ public class RegionMaker {
 			out = calcPostDomOut(mth, block, mth.getExitBlocks());
 		} else {
 			BlockNode loopEnd = loop.getEnd();
-			// treat 'continue' as exit
-			out = calcPostDomOut(mth, block, loopEnd.getPredecessors());
-			if (out != null) {
-				insertContinueInSwitch(block, out, loopEnd);
+			stack.addExit(loop.getStart());
+			if (stack.containsExit(block)
+					|| block == loopEnd
+					|| loopEnd.getPredecessors().contains(block)) {
+				// in exits or last insn in loop => no 'out' block
+				out = null;
 			} else {
-				// no 'continue'
-				out = calcPostDomOut(mth, block, Collections.singletonList(loopEnd));
+				// treat 'continue' as exit
+				out = calcPostDomOut(mth, block, loopEnd.getPredecessors());
+				if (out != null) {
+					insertContinueInSwitch(block, out, loopEnd);
+				} else {
+					// no 'continue'
+					out = calcPostDomOut(mth, block, Collections.singletonList(loopEnd));
+				}
 			}
+			if (out == loop.getStart()) {
+				// no other outs instead back edge to loop start
+				out = null;
+			}
+		}
+		if (out != null && processedBlocks.get(out.getId())) {
+			// out block already processed, prevent endless loop
+			throw new JadxRuntimeException("Failed to find switch 'out' block");
 		}
 
 		SwitchRegion sw = new SwitchRegion(currentRegion, block);

jadx-core/src/main/java/jadx/core/utils/ErrorsCounter.java

@@ -21,6 +21,7 @@ import jadx.core.utils.exceptions.JadxOverflowException;
 
 public class ErrorsCounter {
 	private static final Logger LOG = LoggerFactory.getLogger(ErrorsCounter.class);
+	private static final boolean PRINT_MTH_SIZE = true;
 
 	private final Set<IAttributeNode> errorNodes = new HashSet<>();
 	private int errorsCount;
@@ -40,6 +41,10 @@ public class ErrorsCounter {
 		errorsCount++;
 
 		String msg = formatMsg(node, error);
+		if (PRINT_MTH_SIZE && node instanceof MethodNode) {
+			long insnsCount = ((MethodNode) node).countInsns();
+			msg = "[" + insnsCount + "] " + msg;
+		}
 		if (e == null) {
 			LOG.error(msg);
 		} else if (e instanceof JadxOverflowException) {

jadx-core/src/test/java/jadx/tests/integration/switches/TestSwitchInLoop2.java

@@ -0,0 +1,34 @@
+package jadx.tests.integration.switches;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.tests.api.IntegrationTest;
+
+import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
+
+public class TestSwitchInLoop2 extends IntegrationTest {
+	public static class TestCls {
+		public boolean test() {
+			while (true) {
+				switch (call()) {
+					case 0:
+						return false;
+					case 1:
+						return true;
+				}
+			}
+		}
+
+		private int call() {
+			return 0;
+		}
+	}
+
+	@Test
+	public void test() {
+		assertThat(getClassNode(TestCls.class))
+				.code()
+				.containsOne("while (true) {")
+				.containsOne("switch (call()) {");
+	}
+}