core: ignore errors in debug info parser (fix #176)

jadx-core/src/main/java/jadx/core/dex/visitors/DebugInfoVisitor.java

 package jadx.core.dex.visitors;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.instructions.args.RegisterArg;
 import jadx.core.dex.nodes.BlockNode;
@@ -7,40 +10,50 @@ import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.dex.nodes.parser.DebugInfoParser;
 import jadx.core.utils.BlockUtils;
+import jadx.core.utils.ErrorsCounter;
+import jadx.core.utils.exceptions.DecodeException;
 import jadx.core.utils.exceptions.JadxException;
 
 public class DebugInfoVisitor extends AbstractVisitor {
+
+	private static final Logger LOG = LoggerFactory.getLogger(DebugInfoVisitor.class);
+
 	@Override
 	public void visit(MethodNode mth) throws JadxException {
-		int debugOffset = mth.getDebugInfoOffset();
-		if (debugOffset > 0) {
-			InsnNode[] insnArr = mth.getInstructions();
-			DebugInfoParser debugInfoParser = new DebugInfoParser(mth, debugOffset, insnArr);
-			debugInfoParser.process();
-
-			// set method source line from first instruction
-			if (insnArr.length != 0) {
-				for (InsnNode insn : insnArr) {
-					if (insn != null) {
-						int line = insn.getSourceLine();
-						if (line != 0) {
-							mth.setSourceLine(line - 1);
-						}
-						break;
-					}
-				}
+		try {
+			int debugOffset = mth.getDebugInfoOffset();
+			if (debugOffset > 0) {
+				processDebugInfo(mth, debugOffset);
 			}
-			if (!mth.getReturnType().equals(ArgType.VOID)) {
-				// fix debug info for splitter 'return' instructions
-				for (BlockNode exit : mth.getExitBlocks()) {
-					InsnNode ret = BlockUtils.getLastInsn(exit);
-					if (ret == null) {
-						continue;
-					}
-					InsnNode oldRet = insnArr[ret.getOffset()];
-					if (oldRet == ret) {
-						continue;
-					}
+		} catch (Exception e) {
+			LOG.error("Error in debug info parser: " + ErrorsCounter.formatErrorMsg(mth, e.getMessage()), e);
+		} finally {
+			mth.unloadInsnArr();
+		}
+	}
+
+	private void processDebugInfo(MethodNode mth, int debugOffset) throws DecodeException {
+		InsnNode[] insnArr = mth.getInstructions();
+		DebugInfoParser debugInfoParser = new DebugInfoParser(mth, debugOffset, insnArr);
+		debugInfoParser.process();
+
+		if (insnArr.length != 0) {
+			setMethodSourceLine(mth, insnArr);
+		}
+		if (!mth.getReturnType().equals(ArgType.VOID)) {
+			setLineForReturn(mth, insnArr);
+		}
+	}
+
+	/**
+	 * Fix debug info for splitter 'return' instructions
+	 */
+	private void setLineForReturn(MethodNode mth, InsnNode[] insnArr) {
+		for (BlockNode exit : mth.getExitBlocks()) {
+			InsnNode ret = BlockUtils.getLastInsn(exit);
+			if (ret != null) {
+				InsnNode oldRet = insnArr[ret.getOffset()];
+				if (oldRet != ret) {
 					RegisterArg oldArg = (RegisterArg) oldRet.getArg(0);
 					RegisterArg newArg = (RegisterArg) ret.getArg(0);
 					newArg.mergeDebugInfo(oldArg.getType(), oldArg.getName());
@@ -48,6 +61,20 @@ public class DebugInfoVisitor extends AbstractVisitor {
 				}
 			}
 		}
-		mth.unloadInsnArr();
+	}
+
+	/**
+	 * Set method source line from first instruction
+	 */
+	private void setMethodSourceLine(MethodNode mth, InsnNode[] insnArr) {
+		for (InsnNode insn : insnArr) {
+			if (insn != null) {
+				int line = insn.getSourceLine();
+				if (line != 0) {
+					mth.setSourceLine(line - 1);
+				}
+				return;
+			}
+		}
 	}
 }