From 62a28c8e88f3754a271b2ffd858250eb314fb05b Mon Sep 17 00:00:00 2001
From: Skylot <skylot@gmail.com>
Date: Sun, 7 Apr 2013 15:39:50 +0400
Subject: [PATCH] Remove empty public constructors

---
 src/main/java/jadx/Main.java                  |  3 +-
 src/main/java/jadx/dex/info/AccessInfo.java   | 18 ++++++++++--
 src/main/java/jadx/dex/info/ClassInfo.java    |  4 +--
 .../java/jadx/dex/visitors/ClassModifier.java | 28 +++++++++++++++++--
 4 files changed, 44 insertions(+), 9 deletions(-)

diff --git a/src/main/java/jadx/Main.java b/src/main/java/jadx/Main.java
index 2438139b2..0d0aab170 100644
--- a/src/main/java/jadx/Main.java
+++ b/src/main/java/jadx/Main.java
@@ -98,8 +98,6 @@ public class Main {
 			if (args.isRawCFGOutput())
 				passes.add(new DotGraphVisitor(args.getOutDir(), false, true));
 
-			passes.add(new ClassModifier());
-
 			passes.add(new ModVisitor());
 			passes.add(new EnumVisitor());
 
@@ -115,6 +113,7 @@ public class Main {
 			if (args.isCFGOutput())
 				passes.add(new DotGraphVisitor(args.getOutDir(), true));
 
+			passes.add(new ClassModifier());
 			passes.add(new CleanRegions());
 		}
 		passes.add(new CodeGen(args));
diff --git a/src/main/java/jadx/dex/info/AccessInfo.java b/src/main/java/jadx/dex/info/AccessInfo.java
index 9a71f0558..437f4c73b 100644
--- a/src/main/java/jadx/dex/info/AccessInfo.java
+++ b/src/main/java/jadx/dex/info/AccessInfo.java
@@ -37,6 +37,18 @@ public class AccessInfo {
 		return new AccessInfo(f, type);
 	}
 
+	public boolean isPublic() {
+		return (accFlags & AccessFlags.ACC_PUBLIC) != 0;
+	}
+
+	public boolean isProtected() {
+		return (accFlags & AccessFlags.ACC_PROTECTED) != 0;
+	}
+
+	public boolean isPrivate() {
+		return (accFlags & AccessFlags.ACC_PRIVATE) != 0;
+	}
+
 	public boolean isAbstract() {
 		return (accFlags & AccessFlags.ACC_ABSTRACT) != 0;
 	}
@@ -87,13 +99,13 @@ public class AccessInfo {
 
 	public String makeString() {
 		StringBuilder code = new StringBuilder();
-		if ((accFlags & AccessFlags.ACC_PUBLIC) != 0)
+		if (isPublic())
 			code.append("public ");
 
-		if ((accFlags & AccessFlags.ACC_PRIVATE) != 0)
+		if (isPrivate())
 			code.append("private ");
 
-		if ((accFlags & AccessFlags.ACC_PROTECTED) != 0)
+		if (isProtected())
 			code.append("protected ");
 
 		if (isStatic())
diff --git a/src/main/java/jadx/dex/info/ClassInfo.java b/src/main/java/jadx/dex/info/ClassInfo.java
index 23f74c08e..d893b093a 100644
--- a/src/main/java/jadx/dex/info/ClassInfo.java
+++ b/src/main/java/jadx/dex/info/ClassInfo.java
@@ -5,12 +5,12 @@ import jadx.dex.instructions.args.ArgType;
 import jadx.dex.nodes.DexNode;
 
 import java.io.File;
-import java.util.HashMap;
 import java.util.Map;
+import java.util.WeakHashMap;
 
 public final class ClassInfo {
 
-	private static final Map<ArgType, ClassInfo> CLASSINFO_CACHE = new HashMap<ArgType, ClassInfo>();
+	private static final Map<ArgType, ClassInfo> CLASSINFO_CACHE = new WeakHashMap<ArgType, ClassInfo>();
 	private static final String DEFAULT_PACKAGE_NAME = "defpackage";
 
 	private final String clsName;
diff --git a/src/main/java/jadx/dex/visitors/ClassModifier.java b/src/main/java/jadx/dex/visitors/ClassModifier.java
index d14e77bee..198fba931 100644
--- a/src/main/java/jadx/dex/visitors/ClassModifier.java
+++ b/src/main/java/jadx/dex/visitors/ClassModifier.java
@@ -1,11 +1,13 @@
 package jadx.dex.visitors;
 
 import jadx.dex.info.AccessInfo;
+import jadx.dex.nodes.BlockNode;
 import jadx.dex.nodes.ClassNode;
 import jadx.dex.nodes.MethodNode;
 import jadx.utils.exceptions.JadxException;
 
 import java.util.Iterator;
+import java.util.List;
 
 public class ClassModifier extends AbstractVisitor {
 
@@ -21,10 +23,32 @@ public class ClassModifier extends AbstractVisitor {
 
 			// remove bridge methods
 			if (af.isBridge() && af.isSynthetic()) {
-				// TODO make some checks before deleting
-				it.remove();
+				if (!isMethodIdUniq(cls, mth)) {
+					// TODO add more checks before method deletion
+					it.remove();
+				}
+			}
+
+			// remove public empty constructors
+			if (af.isConstructor()
+					&& af.isPublic()
+					&& mth.getArguments(false).isEmpty()) {
+				List<BlockNode> bb = mth.getBasicBlocks();
+				if (bb.isEmpty() || (bb.size() == 1 && bb.get(0).getInstructions().isEmpty())) {
+					it.remove();
+				}
 			}
 		}
 		return false;
 	}
+
+	private boolean isMethodIdUniq(ClassNode cls, MethodNode mth) {
+		String shortId = mth.getMethodInfo().getShortId();
+		for (MethodNode otherMth : cls.getMethods()) {
+			if (otherMth.getMethodInfo().getShortId().equals(shortId)
+					&& otherMth != mth)
+				return false;
+		}
+		return true;
+	}
 }