core: fix method inline

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

@@ -13,13 +13,13 @@ import jadx.core.dex.visitors.IDexTreeVisitor;
 import jadx.core.dex.visitors.MethodInlineVisitor;
 import jadx.core.dex.visitors.ModVisitor;
 import jadx.core.dex.visitors.PrepareForCodeGen;
-import jadx.core.dex.visitors.ssa.SSATransform;
 import jadx.core.dex.visitors.SimplifyVisitor;
 import jadx.core.dex.visitors.regions.CheckRegions;
 import jadx.core.dex.visitors.regions.IfRegionVisitor;
 import jadx.core.dex.visitors.regions.ProcessVariables;
 import jadx.core.dex.visitors.regions.RegionMakerVisitor;
 import jadx.core.dex.visitors.ssa.EliminatePhiNodes;
+import jadx.core.dex.visitors.ssa.SSATransform;
 import jadx.core.dex.visitors.typeinference.FinishTypeInference;
 import jadx.core.dex.visitors.typeinference.TypeInference;
 import jadx.core.utils.Utils;

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

@@ -3,7 +3,6 @@ package jadx.core.codegen;
 import jadx.core.dex.attributes.AttributeFlag;
 import jadx.core.dex.attributes.AttributeType;
 import jadx.core.dex.attributes.FieldReplaceAttr;
-import jadx.core.dex.attributes.IAttribute;
 import jadx.core.dex.attributes.MethodInlineAttr;
 import jadx.core.dex.info.ClassInfo;
 import jadx.core.dex.info.FieldInfo;
@@ -583,9 +582,7 @@ public class InsnGen {
 
 		// inline method
 		MethodNode callMthNode = mth.dex().resolveMethod(callMth);
-		if (callMthNode != null
-				&& callMthNode.getAttributes().contains(AttributeType.METHOD_INLINE)) {
-			inlineMethod(callMthNode, insn, code);
+		if (callMthNode != null && inlineMethod(callMthNode, insn, code)) {
 			return;
 		}
 
@@ -662,9 +659,12 @@ public class InsnGen {
 		}
 	}
 
-	private void inlineMethod(MethodNode callMthNode, InvokeNode insn, CodeWriter code) throws CodegenException {
-		IAttribute mia = callMthNode.getAttributes().get(AttributeType.METHOD_INLINE);
-		InsnNode inl = ((MethodInlineAttr) mia).getInsn();
+	private boolean inlineMethod(MethodNode callMthNode, InvokeNode insn, CodeWriter code) throws CodegenException {
+		MethodInlineAttr mia = (MethodInlineAttr) callMthNode.getAttributes().get(AttributeType.METHOD_INLINE);
+		if (mia == null) {
+			return false;
+		}
+		InsnNode inl = mia.getInsn();
 		if (callMthNode.getMethodInfo().getArgumentsTypes().isEmpty()) {
 			makeInsn(inl, code, Flags.BODY_ONLY);
 		} else {
@@ -681,12 +681,13 @@ public class InsnGen {
 			inl.getRegisterArgs(inlArgs);
 			Map<RegisterArg, InsnArg> toRevert = new HashMap<RegisterArg, InsnArg>();
 			for (RegisterArg r : inlArgs) {
-				if (r.getRegNum() >= regs.length) {
-					LOG.warn("Unknown register number {} in method call: {}, {}", r, callMthNode, mth);
+				int regNum = r.getRegNum();
+				if (regNum >= regs.length) {
+					LOG.warn("Unknown register number {} in method call: {} from {}", r, callMthNode, mth);
 				} else {
-					InsnArg repl = regs[r.getRegNum()];
+					InsnArg repl = regs[regNum];
 					if (repl == null) {
-						LOG.warn("Not passed register {} in method call: {}, {}", r, callMthNode, mth);
+						LOG.warn("Not passed register {} in method call: {} from {}", r, callMthNode, mth);
 					} else {
 						inl.replaceArg(r, repl);
 						toRevert.put(r, repl);
@@ -694,11 +695,12 @@ public class InsnGen {
 				}
 			}
 			makeInsn(inl, code, Flags.BODY_ONLY);
-			// revert changes
+			// revert changes in 'MethodInlineAttr'
 			for (Map.Entry<RegisterArg, InsnArg> e : toRevert.entrySet()) {
 				inl.replaceArg(e.getValue(), e.getKey());
 			}
 		}
+		return true;
 	}
 
 	private void makeTernary(TernaryInsn insn, CodeWriter code, EnumSet<Flags> state) throws CodegenException {

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

@@ -81,15 +81,16 @@ public class InsnNode extends LineAttrNode {
 		arguments.set(n, arg);
 	}
 
+	/**
+	 * Replace instruction arg with another using recursive search.
+	 * <br>
+	 * <b>Caution:</b> this method don't change usage information for replaced argument.
+	 */
 	public boolean replaceArg(InsnArg from, InsnArg to) {
 		int count = getArgsCount();
 		for (int i = 0; i < count; i++) {
 			InsnArg arg = arguments.get(i);
 			if (arg == from) {
-				if (arg.isRegister()) {
-					RegisterArg registerArg = (RegisterArg) arg;
-					registerArg.getSVar().removeUse(registerArg);
-				}
 				setArg(i, to);
 				return true;
 			}

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

@@ -36,6 +36,7 @@ public class MethodInlineVisitor extends AbstractVisitor {
 			BlockNode block = mth.getBasicBlocks().get(1);
 			InsnNode insn = block.getInstructions().get(0);
 			InsnNode inl = new InsnNode(InsnType.ARGS, 1);
+			// set arg from 'return' instruction
 			inl.addArg(insn.getArg(0));
 			addInlineAttr(mth, inl);
 		} else {