Avoid variable names clash

src/main/java/jadx/codegen/InsnGen.java

@@ -101,7 +101,7 @@ public class InsnGen {
 	}
 
 	public String declareVar(RegisterArg arg) throws CodegenException {
-		return useType(arg.getType()) + " " + arg(arg);
+		return useType(arg.getType()) + " " + mgen.assignArg(arg);
 	}
 
 	private String lit(LiteralArg arg) {

src/main/java/jadx/codegen/MethodGen.java

@@ -20,12 +20,9 @@ import jadx.utils.Utils;
 import jadx.utils.exceptions.CodegenException;
 import jadx.utils.exceptions.DecodeException;
 
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
 
 import org.slf4j.Logger;
@@ -37,12 +34,12 @@ public class MethodGen {
 	private static final Logger LOG = LoggerFactory.getLogger(MethodGen.class);
 
 	private final MethodNode mth;
-	private final Set<String> mthArgsDecls;
-	private final Map<String, ArgType> varDecls = new HashMap<String, ArgType>();
 	private final ClassGen classGen;
 	private final boolean fallback;
 	private final AnnotationGen annotationGen;
 
+	private final Set<String> varNames = new HashSet<String>();
+
 	public MethodGen(ClassGen classGen, MethodNode mth) {
 		this.mth = mth;
 		this.classGen = classGen;
@@ -50,9 +47,8 @@ public class MethodGen {
 		this.annotationGen = classGen.getAnnotationGen();
 
 		List<RegisterArg> args = mth.getArguments(true);
-		mthArgsDecls = new HashSet<String>(args.size());
 		for (RegisterArg arg : args) {
-			mthArgsDecls.add(makeArgName(arg));
+			varNames.add(makeArgName(arg));
 		}
 	}
 
@@ -183,11 +179,28 @@ public class MethodGen {
 	 */
 	public String assignArg(RegisterArg arg) {
 		String name = makeArgName(arg);
-		if (!mthArgsDecls.contains(name))
-			varDecls.put(name, arg.getType());
+		if (varNames.add(name))
+			return name;
+
+		if (fallback)
+			return name;
+
+		name = getUniqVarName(name);
+		arg.getTypedVar().setName(name);
 		return name;
 	}
 
+	private String getUniqVarName(String name) {
+		String r;
+		int i = 2;
+		do {
+			r = name + i;
+			i++;
+		} while (varNames.contains(r));
+		varNames.add(r);
+		return r;
+	}
+
 	private void makeInitCode(CodeWriter code) throws CodegenException {
 		InsnGen igen = new InsnGen(this, mth, fallback);
 		// generate super call
@@ -195,17 +208,6 @@ public class MethodGen {
 			igen.makeInsn(mth.getSuperCall(), code);
 	}
 
-	public void makeVariablesDeclaration(CodeWriter code) {
-		for (Entry<String, ArgType> var : varDecls.entrySet()) {
-			code.startLine(TypeGen.translate(classGen, var.getValue()));
-			code.add(" ");
-			code.add(var.getKey());
-			code.add(";");
-		}
-		if (!varDecls.isEmpty())
-			code.endl();
-	}
-
 	public CodeWriter makeInstructions(int mthIndent) throws CodegenException {
 		CodeWriter code = new CodeWriter(mthIndent + 1);
 
@@ -242,7 +244,6 @@ public class MethodGen {
 				(new RegionGen(this, mth)).makeRegion(insns, mth.getRegion());
 
 				makeInitCode(code);
-				makeVariablesDeclaration(code);
 				code.add(insns);
 			} else {
 				makeFallbackMethod(code, mth);

src/main/java/jadx/dex/visitors/regions/ProcessVariables.java

@@ -107,13 +107,16 @@ public class ProcessVariables extends AbstractVisitor {
 
 		// reduce assigns map
 		List<RegisterArg> mthArgs = mth.getArguments(true);
+		for (RegisterArg arg : mthArgs) {
+			usageMap.remove(arg);
+		}
+
 		for (Iterator<Entry<RegisterArg, Usage>> it = usageMap.entrySet().iterator(); it.hasNext();) {
 			Entry<RegisterArg, Usage> entry = it.next();
 			Usage u = entry.getValue();
-			RegisterArg r = u.getArg();
 
-			// if no assigns or method argument => remove
-			if (u.getAssigns().isEmpty() || mthArgs.indexOf(r) != -1) {
+			// if no assigns => remove
+			if (u.getAssigns().isEmpty()) {
 				it.remove();
 				continue;
 			}
@@ -122,7 +125,7 @@ public class ProcessVariables extends AbstractVisitor {
 			for (IRegion assignRegion : u.getAssigns()) {
 				if (u.getArgRegion() == assignRegion
 						&& canDeclareInRegion(u, assignRegion)) {
-					r.getParentInsn().getAttributes().add(new DeclareVariableAttr());
+					u.getArg().getParentInsn().getAttributes().add(new DeclareVariableAttr());
 					it.remove();
 					break;
 				}
@@ -132,8 +135,8 @@ public class ProcessVariables extends AbstractVisitor {
 		// apply
 		for (Entry<RegisterArg, Usage> entry : usageMap.entrySet()) {
 			Usage u = entry.getValue();
-			// find common region which contains all usage regions
 
+			// find region which contain all usage regions
 			Set<IRegion> set = u.getUseRegions();
 			for (Iterator<IRegion> it = set.iterator(); it.hasNext();) {
 				IRegion r = it.next();

src/samples/java/jadx/samples/TestCF2.java

@@ -4,6 +4,18 @@ public class TestCF2 extends AbstractTest {
 	private final Object ready_mutex = new Object();
 	private boolean ready = false;
 
+	public int simple_loops() throws InterruptedException {
+		int[] a = new int[] { 1, 2, 4, 6, 8 };
+		int b = 0;
+		for (int i = 0; i < a.length; i++) {
+			b += a[i];
+		}
+		for (long i = b; i > 0; i--) {
+			b += i;
+		}
+		return b;
+	}
+
 	/**
 	 * Test infinite loop
 	 */
@@ -92,6 +104,7 @@ public class TestCF2 extends AbstractTest {
 
 	@Override
 	public boolean testRun() throws Exception {
+		assertEquals(simple_loops(), 252);
 		// TODO add checks
 		return true;
 	}