Cleanup block removal

src/main/java/info/sigterm/deob/Deob.java

@@ -3,7 +3,9 @@ package info.sigterm.deob;
 import info.sigterm.deob.execution.Execution;
 import info.sigterm.deob.pool.NameAndType;
 import info.sigterm.deob.attributes.Code;
+import info.sigterm.deob.attributes.code.Block;
 import info.sigterm.deob.attributes.code.Instruction;
+import info.sigterm.deob.attributes.code.Instructions;
 import info.sigterm.deob.attributes.code.instruction.types.LVTInstruction;
 
 import java.io.ByteArrayOutputStream;
@@ -132,27 +134,18 @@ public class Deob
 				if (m.getCode() == null)
 					continue;
 				
-				boolean check = false, remove = false;
-				for (Instruction ins : new ArrayList<>(m.getCode().getInstructions().getInstructions()))
+				Instructions ins = m.getCode().getInstructions();
+				int count = 0;
+				for (Block b : new ArrayList<>(ins.getBlocks()))
 				{
-					if (remove)
+					// first block is the entrypoint, so its always used
+					if (count++ == 0)
+						continue;
+					
+					if (b.begin.from.isEmpty() && b.begin.exce.isEmpty())
 					{
-						m.getCode().getInstructions().remove(ins);
-					}
-					if (check)
-					{
-						if (ins.from.isEmpty() && ins.exce.isEmpty())
-						{
-							remove = true;
-							m.getCode().getInstructions().remove(ins);
-							++i;
-						}
-						check = false;
-					}
-					if (ins.isTerminal())
-					{
-						check = true;
-						remove = false;
+						ins.remove(b);
+						++i;
 					}
 				}
 			}

src/main/java/info/sigterm/deob/attributes/code/Block.java

@@ -0,0 +1,10 @@
+package info.sigterm.deob.attributes.code;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Block
+{
+	public Instruction begin, end;
+	public List<Instruction> instructions = new ArrayList<>();
+}

src/main/java/info/sigterm/deob/attributes/code/Instruction.java

@@ -11,6 +11,7 @@ import java.util.List;
 public abstract class Instruction
 {
 	private Instructions instructions;
+	public Block block;
 	private InstructionType type;
 
 	private int pc; // offset into method this instructions resides at
@@ -29,6 +30,8 @@ public abstract class Instruction
 	
 	protected void remove()
 	{
+		assert block == null;
+		
 		for (Instruction i : jump)
 			i.from.remove(this);
 		jump.clear();

src/main/java/info/sigterm/deob/attributes/code/Instructions.java

@@ -14,6 +14,7 @@ public class Instructions
 {
 	private Code code;
 	private List<Instruction> instructions = new ArrayList<>();
+	private List<Block> blocks = new ArrayList<>();
 
 	public Instructions(Code code) throws IOException
 	{
@@ -48,6 +49,7 @@ public class Instructions
 		assert pc == length;
 
 		buildJumpGraph();
+		buildBlocks();
 	}
 	
 	public List<Instruction> getInstructions()
@@ -55,12 +57,46 @@ public class Instructions
 		return instructions;
 	}
 	
+	public List<Block> getBlocks()
+	{
+		return blocks;
+	}
+	
 	public void remove(Instruction ins)
 	{
 		ins.remove();
 		instructions.remove(ins);
 	}
 	
+	public void remove(Block block)
+	{
+		blocks.remove(block);
+		
+		for (Instruction i : block.instructions)
+			instructions.remove(i);
+	}
+	
+	public void buildBlocks()
+	{
+		Block current = null;
+		for (Instruction i : instructions)
+		{
+			if (current == null)
+			{
+				current = new Block();
+				current.begin = i;
+			}
+			i.block = current;
+			current.instructions.add(i);
+			if (i.isTerminal())
+			{
+				current.end = i;
+				blocks.add(current);
+				current = null;
+			}
+		}
+	}
+	
 	public void write(DataOutputStream out) throws IOException
 	{
 		ByteArrayOutputStream b = new ByteArrayOutputStream();