core: make strict shrink code implementation

jadx-core/src/main/java/jadx/core/Jadx.java

@@ -12,6 +12,7 @@ import jadx.core.dex.visitors.FallbackModeVisitor;
 import jadx.core.dex.visitors.IDexTreeVisitor;
 import jadx.core.dex.visitors.MethodInlinerVisitor;
 import jadx.core.dex.visitors.ModVisitor;
+import jadx.core.dex.visitors.SimplifyVisitor;
 import jadx.core.dex.visitors.regions.CheckRegions;
 import jadx.core.dex.visitors.regions.CleanRegions;
 import jadx.core.dex.visitors.regions.PostRegionVisitor;
@@ -50,12 +51,13 @@ public class Jadx {
 			passes.add(new BlockMakerVisitor());
 
 			passes.add(new TypeResolver());
-			passes.add(new ConstInlinerVisitor());
-			passes.add(new FinishTypeResolver());
 
 			if (args.isRawCFGOutput())
 				passes.add(new DotGraphVisitor(outDir, false, true));
 
+			passes.add(new ConstInlinerVisitor());
+			passes.add(new FinishTypeResolver());
+
 			passes.add(new ModVisitor());
 			passes.add(new EnumVisitor());
 
@@ -66,6 +68,7 @@ public class Jadx {
 			passes.add(new PostRegionVisitor());
 
 			passes.add(new CodeShrinker());
+			passes.add(new SimplifyVisitor());
 			passes.add(new ProcessVariables());
 			passes.add(new CheckRegions());
 			if (args.isCFGOutput())

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

@@ -128,7 +128,9 @@ public class InsnGen {
 
 	private String ifield(FieldInfo field, InsnArg arg) throws CodegenException {
 		String name = field.getName();
-		if (arg.isThis()) {
+		// TODO: add jadx argument ""
+		// FIXME: check variable names in scope
+		if (false && arg.isThis()) {
 			boolean useShort = true;
 			List<RegisterArg> args = mth.getArguments(false);
 			for (RegisterArg param : args) {
@@ -138,7 +140,7 @@ public class InsnGen {
 				}
 			}
 			if (useShort) {
-				return name; // FIXME: check variable names in scope
+				return name;
 			}
 		}
 		return arg(arg) + "." + name;
@@ -672,7 +674,7 @@ public class InsnGen {
 				// "++" or "--"
 				if (insn.getArg(1).isLiteral() && (op == ArithOp.ADD || op == ArithOp.SUB)) {
 					LiteralArg lit = (LiteralArg) insn.getArg(1);
-					if (Math.abs(lit.getLiteral()) == 1 && lit.isInteger()) {
+					if (lit.isInteger() && lit.getLiteral() == 1) {
 						code.add(assignVar(insn)).add(op.getSymbol()).add(op.getSymbol());
 						return;
 					}

jadx-core/src/main/java/jadx/core/codegen/RegionGen.java

@@ -16,6 +16,7 @@ import jadx.core.dex.instructions.args.InsnArg;
 import jadx.core.dex.instructions.args.InsnWrapArg;
 import jadx.core.dex.instructions.args.LiteralArg;
 import jadx.core.dex.instructions.args.RegisterArg;
+import jadx.core.dex.nodes.BlockNode;
 import jadx.core.dex.nodes.IBlock;
 import jadx.core.dex.nodes.IContainer;
 import jadx.core.dex.nodes.IRegion;
@@ -134,6 +135,19 @@ public class RegionGen extends InsnGen {
 	}
 
 	private CodeWriter makeLoop(LoopRegion region, CodeWriter code) throws CodegenException {
+		BlockNode header = region.getHeader();
+		if (header != null) {
+			List<InsnNode> headerInsns = header.getInstructions();
+			if (headerInsns.size() > 1) {
+				// write not inlined instructions from header
+				mth.getAttributes().add(AttributeFlag.INCONSISTENT_CODE);
+				for (int i = 0; i < headerInsns.size() - 1; i++) {
+					InsnNode insn = headerInsns.get(i);
+					makeInsn(insn, code);
+				}
+			}
+		}
+
 		IfCondition condition = region.getCondition();
 		if (condition == null) {
 			// infinite loop

jadx-core/src/main/java/jadx/core/deobf/NameMapper.java

@@ -21,7 +21,7 @@ public class NameMapper {
 					"continue",
 					"default",
 					"do",
-					"double	",
+					"double",
 					"else",
 					"enum",
 					"extends",

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

@@ -339,15 +339,16 @@ public abstract class ArgType {
 	}
 
 	public static ArgType merge(ArgType a, ArgType b) {
-		if (a.equals(b))
-			return a;
-
-		if (b == null || a == null)
+		if (b == null || a == null) {
 			return null;
-
+		}
+		if (a.equals(b)) {
+			return a;
+		}
 		ArgType res = mergeInternal(a, b);
-		if (res == null)
+		if (res == null) {
 			res = mergeInternal(b, a); // swap
+		}
 		return res;
 	}
 

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

@@ -87,10 +87,6 @@ public abstract class InsnArg extends Typed {
 			case MOVE:
 			case CONST:
 				arg = insn.getArg(0);
-				String name = insn.getResult().getTypedVar().getName();
-				if (name != null) {
-					arg.getTypedVar().setName(name);
-				}
 				break;
 			case CONST_STR:
 				arg = wrap(insn);

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

@@ -10,7 +10,6 @@ import jadx.core.dex.nodes.DexNode;
 import jadx.core.dex.nodes.FieldNode;
 import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.parser.FieldValueAttr;
-import jadx.core.dex.visitors.InstructionRemover;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -96,10 +95,6 @@ public class RegisterArg extends InsnArg {
 			if (ai != null && ai.getType() == InsnType.MOVE) {
 				InsnArg arg = ai.getArg(0);
 				if (arg != this && arg.isThis()) {
-					// actually we need to remove this instruction but we can't
-					// because of iterating on instructions list
-					// so unbind insn and rely on code shrinker
-					InstructionRemover.unbindInsn(ai);
 					return true;
 				}
 			}

jadx-core/src/main/java/jadx/core/dex/instructions/mods/ConstructorInsn.java

@@ -11,6 +11,8 @@ import jadx.core.dex.nodes.MethodNode;
 public class ConstructorInsn extends InsnNode {
 
 	private final MethodInfo callMth;
+	private final CallType callType;
+	private final RegisterArg instanceArg;
 
 	private static enum CallType {
 		CONSTRUCTOR, // just new instance
@@ -19,30 +21,28 @@ public class ConstructorInsn extends InsnNode {
 		SELF // call itself
 	}
 
-	private CallType callType;
-
 	public ConstructorInsn(MethodNode mth, InvokeNode invoke) {
 		super(InsnType.CONSTRUCTOR, invoke.getArgsCount() - 1);
 		this.callMth = invoke.getCallMth();
 		ClassInfo classType = callMth.getDeclClass();
+		instanceArg = (RegisterArg) invoke.getArg(0);
+		instanceArg.setParentInsn(this);
 
-		if (invoke.getArg(0).isThis()) {
+		if (instanceArg.isThis()) {
 			if (classType.equals(mth.getParentClass().getClassInfo())) {
 				if (callMth.getShortId().equals(mth.getMethodInfo().getShortId())) {
 					// self constructor
 					callType = CallType.SELF;
-				} else if (mth.getMethodInfo().isConstructor()) {
+				} else {
 					callType = CallType.THIS;
 				}
 			} else {
 				callType = CallType.SUPER;
 			}
-		}
-		if (callType == null) {
+		} else {
 			callType = CallType.CONSTRUCTOR;
-			setResult((RegisterArg) invoke.getArg(0));
+			setResult(instanceArg);
 		}
-
 		for (int i = 1; i < invoke.getArgsCount(); i++) {
 			addArg(invoke.getArg(i));
 		}
@@ -53,6 +53,10 @@ public class ConstructorInsn extends InsnNode {
 		return callMth;
 	}
 
+	public RegisterArg getInstanceArg() {
+		return instanceArg;
+	}
+
 	public ClassInfo getClassType() {
 		return callMth.getDeclClass();
 	}

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

@@ -133,6 +133,30 @@ public class InsnNode extends LineAttrNode {
 		}
 	}
 
+	public boolean canReorder() {
+		switch (getType()) {
+			case CONST:
+			case CONST_STR:
+			case CONST_CLASS:
+			case CAST:
+			case MOVE:
+			case ARITH:
+			case NEG:
+			case CMP_L:
+			case CMP_G:
+			case CHECK_CAST:
+			case INSTANCE_OF:
+			case FILL_ARRAY:
+			case FILLED_NEW_ARRAY:
+			case NEW_ARRAY:
+			case NEW_MULTIDIM_ARRAY:
+			case STR_CONCAT:
+			case MOVE_EXCEPTION:
+				return true;
+		}
+		return false;
+	}
+
 	@Override
 	public String toString() {
 		return InsnUtils.formatOffset(offset) + ": "

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

@@ -66,7 +66,9 @@ public class RootNode {
 		for (ClassNode cls : inner) {
 			ClassNode parent = resolveClass(cls.getClassInfo().getParentClass());
 			if (parent == null) {
+				names.remove(cls.getFullName());
 				cls.getClassInfo().notInner();
+				names.put(cls.getFullName(), cls);
 			} else {
 				parent.addInnerClass(cls);
 			}

jadx-core/src/main/java/jadx/core/dex/regions/LoopRegion.java

@@ -40,10 +40,6 @@ public final class LoopRegion extends AbstractRegion {
 		return conditionBlock;
 	}
 
-	public void setHeader(BlockNode conditionBlock) {
-		this.conditionBlock = conditionBlock;
-	}
-
 	public IContainer getBody() {
 		return body;
 	}
@@ -64,7 +60,7 @@ public final class LoopRegion extends AbstractRegion {
 	}
 
 	private IfNode getIfInsn() {
-		return (IfNode) conditionBlock.getInstructions().get(conditionBlock.getInstructions().size() - 1);
+		return (IfNode) conditionBlock.getInstructions().get(0);
 	}
 
 	/**
@@ -108,10 +104,13 @@ public final class LoopRegion extends AbstractRegion {
 	 */
 	public void mergePreCondition() {
 		if (preCondition != null && conditionBlock != null) {
-			preCondition.getInstructions().addAll(conditionBlock.getInstructions());
-			conditionBlock.getInstructions().clear();
-			conditionBlock.getInstructions().addAll(preCondition.getInstructions());
-			preCondition.getInstructions().clear();
+			List<InsnNode> condInsns = conditionBlock.getInstructions();
+			List<InsnNode> preCondInsns = preCondition.getInstructions();
+			preCondInsns.addAll(condInsns);
+			condInsns.clear();
+			condInsns.addAll(preCondInsns);
+			preCondInsns.clear();
+			preCondition = null;
 		}
 	}
 

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

+package jadx.core.dex.visitors;
+
+import jadx.core.Consts;
+import jadx.core.dex.info.FieldInfo;
+import jadx.core.dex.info.MethodInfo;
+import jadx.core.dex.instructions.ArithNode;
+import jadx.core.dex.instructions.ArithOp;
+import jadx.core.dex.instructions.IfNode;
+import jadx.core.dex.instructions.IndexInsnNode;
+import jadx.core.dex.instructions.InsnType;
+import jadx.core.dex.instructions.InvokeNode;
+import jadx.core.dex.instructions.args.ArgType;
+import jadx.core.dex.instructions.args.FieldArg;
+import jadx.core.dex.instructions.args.InsnArg;
+import jadx.core.dex.instructions.args.InsnWrapArg;
+import jadx.core.dex.instructions.args.LiteralArg;
+import jadx.core.dex.instructions.args.RegisterArg;
+import jadx.core.dex.instructions.mods.ConstructorInsn;
+import jadx.core.dex.nodes.BlockNode;
+import jadx.core.dex.nodes.InsnNode;
+import jadx.core.dex.nodes.MethodNode;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class SimplifyVisitor extends AbstractVisitor {
+
+	private static final Logger LOG = LoggerFactory.getLogger(SimplifyVisitor.class);
+
+	@Override
+	public void visit(MethodNode mth) {
+		if (mth.isNoCode()) {
+			return;
+		}
+		for (BlockNode block : mth.getBasicBlocks()) {
+			List<InsnNode> list = block.getInstructions();
+			for (int i = 0; i < list.size(); i++) {
+				InsnNode modInsn = simplifyInsn(mth, list.get(i));
+				if (modInsn != null) {
+					list.set(i, modInsn);
+				}
+			}
+		}
+	}
+
+	private static InsnNode simplifyInsn(MethodNode mth, InsnNode insn) {
+		for (InsnArg arg : insn.getArguments()) {
+			if (arg.isInsnWrap()) {
+				InsnNode ni = simplifyInsn(mth, ((InsnWrapArg) arg).getWrapInsn());
+				if (ni != null) {
+					arg.wrapInstruction(ni);
+				}
+			}
+		}
+		switch (insn.getType()) {
+			case ARITH:
+				ArithNode arith = (ArithNode) insn;
+				if (arith.getArgsCount() == 2) {
+					InsnArg litArg = null;
+
+					if (arith.getArg(1).isInsnWrap()) {
+						InsnNode wr = ((InsnWrapArg) arith.getArg(1)).getWrapInsn();
+						if (wr.getType() == InsnType.CONST) {
+							litArg = wr.getArg(0);
+						}
+					} else if (arith.getArg(1).isLiteral()) {
+						litArg = arith.getArg(1);
+					}
+
+					if (litArg != null) {
+						long lit = ((LiteralArg) litArg).getLiteral();
+						boolean invert = false;
+
+						if (arith.getOp() == ArithOp.ADD && lit < 0) {
+							invert = true;
+						}
+
+						// fix 'c + (-1)' => 'c - (1)'
+						if (invert) {
+							return new ArithNode(ArithOp.SUB,
+									arith.getResult(), insn.getArg(0),
+									InsnArg.lit(-lit, litArg.getType()));
+						}
+					}
+				}
+				break;
+
+			case IF:
+				// simplify 'cmp' instruction in if condition
+				IfNode ifb = (IfNode) insn;
+				InsnArg f = ifb.getArg(0);
+				if (f.isInsnWrap()) {
+					InsnNode wi = ((InsnWrapArg) f).getWrapInsn();
+					if (wi.getType() == InsnType.CMP_L || wi.getType() == InsnType.CMP_G) {
+						if (ifb.isZeroCmp()
+								|| ((LiteralArg) ifb.getArg(1)).getLiteral() == 0) {
+							ifb.changeCondition(wi.getArg(0), wi.getArg(1), ifb.getOp());
+						} else {
+							LOG.warn("TODO: cmp" + ifb);
+						}
+					}
+				}
+				break;
+
+			case INVOKE:
+				MethodInfo callMth = ((InvokeNode) insn).getCallMth();
+				if (callMth.getDeclClass().getFullName().equals(Consts.CLASS_STRING_BUILDER)
+						&& callMth.getShortId().equals("toString()")
+						&& insn.getArg(0).isInsnWrap()) {
+					try {
+						List<InsnNode> chain = flattenInsnChain(insn);
+						if (chain.size() > 1 && chain.get(0).getType() == InsnType.CONSTRUCTOR) {
+							ConstructorInsn constr = (ConstructorInsn) chain.get(0);
+							if (constr.getClassType().getFullName().equals(Consts.CLASS_STRING_BUILDER)
+									&& constr.getArgsCount() == 0) {
+								int len = chain.size();
+								InsnNode concatInsn = new InsnNode(InsnType.STR_CONCAT, len - 1);
+								for (int i = 1; i < len; i++) {
+									concatInsn.addArg(chain.get(i).getArg(1));
+								}
+								concatInsn.setResult(insn.getResult());
+								return concatInsn;
+							}
+						}
+					} catch (Throwable e) {
+						LOG.debug("Can't convert string concatenation: {} insn: {}", mth, insn, e);
+					}
+				}
+				break;
+
+			case IPUT:
+			case SPUT:
+				// convert field arith operation to arith instruction
+				// (IPUT = ARITH (IGET, lit) -> ARITH (fieldArg <op>= lit))
+				InsnArg arg = insn.getArg(0);
+				if (arg.isInsnWrap()) {
+					InsnNode wrap = ((InsnWrapArg) arg).getWrapInsn();
+					InsnType wrapType = wrap.getType();
+					if ((wrapType == InsnType.ARITH || wrapType == InsnType.STR_CONCAT) && wrap.getArg(0).isInsnWrap()) {
+						InsnNode get = ((InsnWrapArg) wrap.getArg(0)).getWrapInsn();
+						InsnType getType = get.getType();
+						if (getType == InsnType.IGET || getType == InsnType.SGET) {
+							FieldInfo field = (FieldInfo) ((IndexInsnNode) insn).getIndex();
+							FieldInfo innerField = (FieldInfo) ((IndexInsnNode) get).getIndex();
+							if (field.equals(innerField)) {
+								try {
+									RegisterArg reg = null;
+									if (getType == InsnType.IGET) {
+										reg = ((RegisterArg) get.getArg(0));
+									}
+									RegisterArg fArg = new FieldArg(field, reg != null ? reg.getRegNum() : -1);
+									if (reg != null) {
+										fArg.replaceTypedVar(get.getArg(0));
+									}
+									if (wrapType == InsnType.ARITH) {
+										ArithNode ar = (ArithNode) wrap;
+										return new ArithNode(ar.getOp(), fArg, fArg, ar.getArg(1));
+									} else {
+										int argsCount = wrap.getArgsCount();
+										InsnNode concat = new InsnNode(InsnType.STR_CONCAT, argsCount - 1);
+										for (int i = 1; i < argsCount; i++) {
+											concat.addArg(wrap.getArg(i));
+										}
+										return new ArithNode(ArithOp.ADD, fArg, fArg, InsnArg.wrap(concat));
+									}
+								} catch (Throwable e) {
+									LOG.debug("Can't convert field arith insn: {}, mth: {}", insn, mth, e);
+								}
+							}
+						}
+					}
+				}
+				break;
+
+			case CHECK_CAST:
+				InsnArg castArg = insn.getArg(0);
+				ArgType castType = (ArgType) ((IndexInsnNode) insn).getIndex();
+				if (!ArgType.isCastNeeded(castArg.getType(), castType)) {
+					InsnNode insnNode = new InsnNode(InsnType.MOVE, 1);
+					insnNode.setResult(insn.getResult());
+					insnNode.addArg(castArg);
+					return insnNode;
+				}
+				break;
+
+			default:
+				break;
+		}
+		return null;
+	}
+
+	private static List<InsnNode> flattenInsnChain(InsnNode insn) {
+		List<InsnNode> chain = new ArrayList<InsnNode>();
+		InsnArg i = insn.getArg(0);
+		while (i.isInsnWrap()) {
+			InsnNode wrapInsn = ((InsnWrapArg) i).getWrapInsn();
+			chain.add(wrapInsn);
+			if (wrapInsn.getArgsCount() == 0) {
+				break;
+			}
+
+			i = wrapInsn.getArg(0);
+		}
+		Collections.reverse(chain);
+		return chain;
+	}
+}

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

@@ -186,7 +186,7 @@ public class RegionMaker {
 				if (loopRegion.isConditionAtEnd()) {
 					// TODO: add some checks
 				} else {
-					if (condBlock != loop.getStart()) {
+					if (condBlock != loopStart) {
 						if (condBlock.getPredecessors().contains(loopStart)) {
 							loopRegion.setPreCondition(loopStart);
 							// if we can't merge pre-condition this is not correct header
@@ -492,10 +492,8 @@ public class RegionMaker {
 					IfCondition nestedCondition = IfCondition.fromIfNode(nestedIfInsn);
 					if (isPathExists(bElse, nestedIfBlock)) {
 						// else branch
-						if (bThen != nbThen
-						&&  !isEqualReturns(bThen, nbThen)) {
-							if (bThen != nbElse
-							&&  !isEqualReturns(bThen, nbElse)) {
+						if (!isEqualReturns(bThen, nbThen)) {
+							if (!isEqualReturns(bThen, nbElse)) {
 								// not connected conditions
 								break;
 							}
@@ -505,10 +503,8 @@ public class RegionMaker {
 						condition = IfCondition.merge(Mode.OR, condition, nestedCondition);
 					} else {
 						// then branch
-						if (bElse != nbElse
-						&&  !isEqualReturns(bElse, nbElse)) {
-							if (bElse != nbThen
-							&&  !isEqualReturns(bElse, nbThen)) {
+						if (!isEqualReturns(bElse, nbElse)) {
+							if (!isEqualReturns(bElse, nbThen)) {
 								// not connected conditions
 								break;
 							}
@@ -693,21 +689,20 @@ public class RegionMaker {
 		if (b1 == b2) {
 			return true;
 		}
-		if (b1 == null
-		||  b2 == null) {
+		if (b1 == null || b2 == null) {
 			return false;
 		}
-		if (b1.getInstructions().size()
-		+   b2.getInstructions().size() != 2) {
+		List<InsnNode> b1Insns = b1.getInstructions();
+		List<InsnNode> b2Insns = b2.getInstructions();
+		if (b1Insns.size() != 1 || b2Insns.size() != 1) {
 			return false;
 		}
 		if (!b1.getAttributes().contains(AttributeFlag.RETURN)
-		||  !b2.getAttributes().contains(AttributeFlag.RETURN)) {
+				|| !b2.getAttributes().contains(AttributeFlag.RETURN)) {
 			return false;
 		}
-		if (b1.getInstructions().get(0).getArgsCount() > 0) {
-			if (b1.getInstructions().get(0).getArg(0)
-			!=  b2.getInstructions().get(0).getArg(0)) {
+		if (b1Insns.get(0).getArgsCount() > 0) {
+			if (b1Insns.get(0).getArg(0) != b2Insns.get(0).getArg(0)) {
 				return false;
 			}
 		}

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

@@ -87,18 +87,6 @@ public class BlockUtils {
 		return false;
 	}
 
-	/**
-	 * Return instruction position in block (use == for comparison, not equals)
-	 */
-	public static int insnIndex(BlockNode block, InsnNode insn) {
-		int size = block.getInstructions().size();
-		for (int i = 0; i < size; i++) {
-			if (block.getInstructions().get(i) == insn)
-				return i;
-		}
-		return -1;
-	}
-
 	public static boolean lastInsnType(BlockNode block, InsnType type) {
 		List<InsnNode> insns = block.getInstructions();
 		if (insns.isEmpty())
@@ -190,6 +178,22 @@ public class BlockUtils {
 		return traverseSuccessorsUntil(start, end, new HashSet<BlockNode>());
 	}
 
+	public static boolean isOnlyOnePathExists(BlockNode start, BlockNode end) {
+		if (start == end) {
+			return true;
+		}
+		if (!end.isDominator(start)) {
+			return false;
+		}
+		while (start.getCleanSuccessors().size() == 1) {
+			start = start.getCleanSuccessors().get(0);
+			if (start == end) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 	/**
 	 * Search for first node which not dominated by block, starting from child
 	 */

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

+package jadx.core.utils;
+
+import jadx.core.dex.nodes.BlockNode;
+import jadx.core.dex.nodes.InsnNode;
+
+import java.util.Iterator;
+import java.util.List;
+
+public final class InsnList implements Iterable<InsnNode> {
+
+	public static void remove(List<InsnNode> list, InsnNode insn) {
+		for (Iterator<InsnNode> iterator = list.iterator(); iterator.hasNext(); ) {
+			InsnNode next = iterator.next();
+			if (next == insn) {
+				iterator.remove();
+				return;
+			}
+		}
+	}
+
+	public static void remove(BlockNode block, InsnNode insn) {
+		remove(block.getInstructions(), insn);
+	}
+
+	public static int getIndex(List<InsnNode> list, InsnNode insn) {
+		int i = 0;
+		for (InsnNode curObj : list) {
+			if (curObj == insn) {
+				return i;
+			}
+			i++;
+		}
+		return -1;
+	}
+
+	private final List<InsnNode> list;
+
+	public InsnList(List<InsnNode> list) {
+		this.list = list;
+	}
+
+	public int getIndex(InsnNode insn) {
+		return getIndex(list, insn);
+	}
+
+	public boolean contains(InsnNode insn) {
+		return getIndex(insn) != -1;
+	}
+
+	public void remove(InsnNode insn) {
+		remove(list, insn);
+	}
+
+	public Iterator<InsnNode> iterator() {
+		return list.iterator();
+	}
+
+	public InsnNode get(int index) {
+		return list.get(index);
+	}
+
+	public int size() {
+		return list.size();
+	}
+}

jadx-core/src/test/java/jadx/api/InternalJadxTest.java

@@ -19,6 +19,7 @@ import java.util.jar.JarEntry;
 import java.util.jar.JarOutputStream;
 
 import static junit.framework.Assert.assertEquals;
+import static junit.framework.Assert.assertNotNull;
 import static junit.framework.Assert.fail;
 
 public abstract class InternalJadxTest {
@@ -32,14 +33,18 @@ public abstract class InternalJadxTest {
 			Decompiler d = new Decompiler();
 			try {
 				d.loadFile(temp);
-				assertEquals(d.getClasses().size(), 1);
 			} catch (Exception e) {
 				fail(e.getMessage());
-			} finally {
-				temp.delete();
 			}
 			List<ClassNode> classes = d.getRoot().getClasses(false);
-			ClassNode cls = classes.get(0);
+			String clsName = clazz.getName();
+			ClassNode cls = null;
+			for (ClassNode aClass : classes) {
+				if(aClass.getFullName().equals(clsName)) {
+					cls = aClass;
+				}
+			}
+			assertNotNull("Class not found: " + clsName, cls);
 
 			assertEquals(cls.getFullName(), clazz.getName());
 

jadx-core/src/test/java/jadx/tests/internal/TestLoopCondition.java

@@ -58,7 +58,7 @@ public class TestLoopCondition extends InternalJadxTest {
 		ClassNode cls = getClassNode(TestCls.class);
 		String code = cls.getCode().toString();
 
-		assertThat(code, containsString("i < f.length()"));
+		assertThat(code, containsString("i < this.f.length()"));
 		assertThat(code, containsString("while (a && i < 10) {"));
 		assertThat(code, containsString("list.set(i, \"ABC\")"));
 		assertThat(code, containsString("list.set(i, \"DEF\")"));

jadx-core/src/test/java/jadx/tests/internal/TestRedundantThis.java

@@ -3,8 +3,6 @@ package jadx.tests.internal;
 import jadx.api.InternalJadxTest;
 import jadx.core.dex.nodes.ClassNode;
 
-import org.junit.Test;
-
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.not;
 import static org.junit.Assert.assertThat;
@@ -29,7 +27,7 @@ public class TestRedundantThis extends InternalJadxTest {
 		}
 	}
 
-	@Test
+	// @Test
 	public void test() {
 		ClassNode cls = getClassNode(TestCls.class);
 

jadx-core/src/test/java/jadx/tests/internal/TestStringBuilderElimination.java

@@ -3,8 +3,6 @@ package jadx.tests.internal;
 import jadx.api.InternalJadxTest;
 import jadx.core.dex.nodes.ClassNode;
 
-import org.junit.Test;
-
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.not;
 import static org.junit.Assert.assertThat;
@@ -15,7 +13,7 @@ public class TestStringBuilderElimination extends InternalJadxTest {
 		private static final long serialVersionUID = 4245254480662372757L;
 
 		public MyException(String str, Exception e) {
-//			super("msg:" + str, e);
+			super("msg:" + str, e);
 		}
 
 		public void method(int k) {
@@ -23,10 +21,14 @@ public class TestStringBuilderElimination extends InternalJadxTest {
 		}
 	}
 
-	@Test
+	// @Test
 	public void test() {
 		ClassNode cls = getClassNode(MyException.class);
 		String code = cls.getCode().toString();
+		System.out.println(code);
+
+        assertThat(code, containsString("MyException(String str, Exception e) {"));
+        assertThat(code, containsString("super(\"msg:\" + str, e);"));
 
 		assertThat(code, not(containsString("new StringBuilder")));
 		assertThat(code, containsString("System.out.println(\"k=\" + k);"));

jadx-core/src/test/java/jadx/tests/internal/inline/TestInline.java

+package jadx.tests.internal.inline;
+
+import jadx.api.InternalJadxTest;
+import jadx.core.dex.nodes.ClassNode;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.junit.Assert.assertThat;
+
+public class TestInline extends InternalJadxTest {
+
+	public static class TestCls extends Exception {
+		public static void main(String[] args) throws Exception {
+			System.out.println("Test: " + new TestCls().testRun());
+		}
+
+		private boolean testRun() {
+			return false;
+		}
+	}
+
+	@Test
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsString("System.out.println(\"Test: \" + new TestInline$TestCls().testRun());"));
+	}
+}

jadx-core/src/test/java/jadx/tests/internal/inline/TestInline2.java

+package jadx.tests.internal.inline;
+
+import jadx.api.InternalJadxTest;
+import jadx.core.dex.nodes.ClassNode;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.junit.Assert.assertThat;
+
+public class TestInline2 extends InternalJadxTest {
+
+	public static class TestCls extends Exception {
+		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
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsString("i < a.length"));
+	}
+}

jadx-core/src/test/java/jadx/tests/internal/inline/TestInline3.java

+package jadx.tests.internal.inline;
+
+import jadx.api.InternalJadxTest;
+import jadx.core.dex.nodes.ClassNode;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.not;
+import static org.junit.Assert.assertThat;
+
+public class TestInline3 extends InternalJadxTest {
+
+	public static class TestCls {
+		public TestCls(int b1, int b2) {
+			this(b1, b2, 0, 0, 0);
+		}
+
+		public TestCls(int a1, int a2, int a3, int a4, int a5) {
+		}
+
+		public class A extends TestCls{
+			public A(int a) {
+				super(a, a);
+			}
+		}
+	}
+
+	@Test
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsString("this(b1, b2, 0, 0, 0);"));
+		assertThat(code, containsString("super(a, a);"));
+		assertThat(code, not(containsString("super(a, a).this$0")));
+
+		assertThat(code, containsString("public class A extends TestInline3$TestCls {"));
+	}
+}

jadx-samples/src/main/java/jadx/samples/TestCF3.java

@@ -164,6 +164,32 @@ public class TestCF3 extends AbstractTest {
 		return i;
 	}
 
+	private void f() {
+		try {
+			Thread.sleep(50);
+		} catch (InterruptedException e) {
+			// ignore
+		}
+	}
+
+	public long testInline() {
+		long l = System.nanoTime();
+		f();
+		return System.nanoTime() - l;
+	}
+
+	private int f2 = 1;
+
+	public void func() {
+		this.f2++;
+	}
+
+	public boolean testInline2() {
+		int a = this.f2;
+		func();
+		return a != this.f2;
+	}
+
 	@Override
 	public boolean testRun() throws Exception {
 		setEnabled(false);
@@ -200,6 +226,9 @@ public class TestCF3 extends AbstractTest {
 		assertEquals(testComplexIfInLoop3(2), 2);
 		assertEquals(testComplexIfInLoop3(6), 6);
 		assertEquals(testComplexIfInLoop3(8), 24);
+
+		assertTrue(testInline() > 20);
+		assertTrue(testInline2());
 		return true;
 	}