core: fix processing of debug info (markup of local variables)

jadx-core/src/main/java/jadx/core/dex/instructions/args/SSAVar.java

@@ -11,6 +11,9 @@ public class SSAVar {
 	private final int version;
 	private VarName varName;
 
+	private int startUseAddr;
+	private int endUseAddr;
+
 	private RegisterArg assign;
 	private final List<RegisterArg> useList = new ArrayList<RegisterArg>(2);
 	private PhiInsn usedInPhi;
@@ -25,12 +28,63 @@ public class SSAVar {
 		if (assign != null) {
 			assign.setSVar(this);
 		}
+
+		startUseAddr = -1;
+		endUseAddr = -1;
 	}
 
 	public int getRegNum() {
 		return regNum;
 	}
 
+	public int getStartAddr() {
+		if (startUseAddr == -1) {
+			calcUsageAddrRange();
+		}
+		return startUseAddr;
+	}
+
+	public int getEndAddr() {
+		if (endUseAddr == -1) {
+			calcUsageAddrRange();
+		}
+
+		return endUseAddr;
+	}
+
+	private void calcUsageAddrRange() {
+		int start = Integer.MAX_VALUE;
+		int end = Integer.MIN_VALUE;
+
+		if (assign != null) {
+			if (assign.getParentInsn() != null) {
+				int insnAddr = assign.getParentInsn().getOffset();
+
+				if (insnAddr >= 0) {
+					start = Math.min(insnAddr, start);
+					end = Math.max(insnAddr, end);
+				}
+			}
+		}
+
+		for (RegisterArg arg : useList) {
+			if (arg.getParentInsn() != null) {
+				int insnAddr = arg.getParentInsn().getOffset();
+
+				if (insnAddr >= 0) {
+					start = Math.min(insnAddr, start);
+					end = Math.max(insnAddr, end);
+				}
+			}
+		}
+
+		if ((start != Integer.MAX_VALUE) 
+				&& (end != Integer.MIN_VALUE)) {
+			startUseAddr = start;
+			endUseAddr = end;
+		}
+	} 
+
 	public int getVersion() {
 		return version;
 	}

jadx-core/src/main/java/jadx/core/dex/nodes/MethodNode.java

@@ -52,6 +52,7 @@ public class MethodNode extends LineAttrNode implements ILoadable {
 	private final Method methodData;
 	private int regsCount;
 	private InsnNode[] instructions;
+	private int codeSize;
 	private int debugInfoOffset;
 	private boolean noCode;
 
@@ -82,6 +83,7 @@ public class MethodNode extends LineAttrNode implements ILoadable {
 		try {
 			if (noCode) {
 				regsCount = 0;
+				codeSize = 0;
 				initMethodTypes();
 				return;
 			}
@@ -94,6 +96,7 @@ public class MethodNode extends LineAttrNode implements ILoadable {
 			InsnDecoder decoder = new InsnDecoder(this);
 			decoder.decodeInsns(mthCode);
 			instructions = decoder.process();
+			codeSize = instructions.length;
 
 			initTryCatches(mthCode);
 			initJumps();
@@ -350,6 +353,10 @@ public class MethodNode extends LineAttrNode implements ILoadable {
 		return noCode;
 	}
 
+	public int getCodeSize() {
+		return codeSize;
+	}
+
 	public InsnNode[] getInstructions() {
 		return instructions;
 	}

jadx-core/src/main/java/jadx/core/dex/nodes/parser/DebugInfoParser.java

@@ -3,6 +3,7 @@ package jadx.core.dex.nodes.parser;
 import jadx.core.dex.attributes.nodes.SourceFileAttr;
 import jadx.core.dex.instructions.args.InsnArg;
 import jadx.core.dex.instructions.args.RegisterArg;
+import jadx.core.dex.instructions.args.SSAVar;
 import jadx.core.dex.nodes.DexNode;
 import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
@@ -112,8 +113,9 @@ public class DebugInfoParser {
 					int regNum = section.readUleb128();
 					LocalVar var = locals[regNum];
 					if (var != null) {
-						var.end(addr, line);
-						setVar(var);
+						if (var.end(addr, line)) {
+							setVar(var);
+						}
 						var.start(addr, line);
 					}
 					break;
@@ -160,7 +162,7 @@ public class DebugInfoParser {
 
 		for (LocalVar var : locals) {
 			if (var != null && !var.isEnd()) {
-				var.end(addr, line);
+				var.end(mth.getCodeSize()-1, line);
 				setVar(var);
 			}
 		}
@@ -236,7 +238,27 @@ public class DebugInfoParser {
 		if (arg != null && arg.isRegister()) {
 			RegisterArg reg = (RegisterArg) arg;
 			if (var.getRegNum() == reg.getRegNum()) {
-				reg.mergeDebugInfo(var.getType(), var.getName());
+				SSAVar ssaVar = reg.getSVar();
+
+				boolean mergeRequired = false;
+
+				if (ssaVar != null) {
+					int ssaEnd = ssaVar.getEndAddr();
+					int ssaStart = ssaVar.getStartAddr();
+					int localStart = var.getStartAddr();
+					int localEnd = var.getEndAddr();
+
+					boolean isIntersected = !((localEnd < ssaStart) || (ssaEnd < localStart));
+					if (isIntersected && (ssaEnd <= localEnd)) {
+						mergeRequired = true;
+					}
+				} else {
+					mergeRequired = true;
+				}
+				
+				if (mergeRequired) {
+					reg.mergeDebugInfo(var.getType(), var.getName());
+				}
 			}
 		}
 	}

jadx-core/src/main/java/jadx/core/dex/nodes/parser/LocalVar.java

@@ -69,9 +69,20 @@ final class LocalVar {
 		this.startAddr = addr;
 	}
 
-	public void end(int addr, int line) {
-		this.isEnd = true;
-		this.endAddr = addr;
+	/**
+	 * Sets end address of local variable
+	 * @param addr address
+	 * @param line source line
+	 * @return <b>true</b> if local variable was active, else <b>false</b>
+	 */
+	public boolean end(int addr, int line) {
+		if (!isEnd) {
+			this.isEnd = true;
+			this.endAddr = addr;
+			return true;
+		}
+
+		return false;
 	}
 
 	public int getRegNum() {

jadx-core/src/main/java/jadx/core/dex/visitors/ssa/SSATransform.java

@@ -80,6 +80,7 @@ public class SSATransform extends AbstractVisitor {
 		}
 		PhiInsn phiInsn = new PhiInsn(regNum, block.getPredecessors().size());
 		phiList.getList().add(phiInsn);
+		phiInsn.setOffset(block.getStartOffset());
 		block.getInstructions().add(0, phiInsn);
 	}