Build jump graph

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

@@ -1,11 +1,17 @@
 package info.sigterm.deob.attributes.code;
 
+import java.util.ArrayList;
+
 public class Instruction
 {
 	private Instructions instructions;
 	private InstructionType type;
-	private int pc;
-	protected int length = 1;
+
+	private int pc; // offset into method this instructions resides at
+	protected int length = 1; // length of this instruction
+
+	private ArrayList<Instruction> jump = new ArrayList<Instruction>(); // instructions which this instruction jumps to
+	private ArrayList<Instruction> from = new ArrayList<Instruction>(); // instructions which jump to this instruction
 
 	public Instruction(Instructions instructions, InstructionType type, int pc)
 	{
@@ -14,8 +20,27 @@ public class Instruction
 		this.pc = pc;
 	}
 
+	public int getPc()
+	{
+		return pc;
+	}
+
 	public int getLength()
 	{
 		return length;
 	}
+
+	protected void addJump(int offset)
+	{
+		Instruction other = instructions.findInstruction(pc + offset);
+		assert other != null;
+		assert other != this;
+
+		this.jump.add(other);
+		other.from.add(this);
+	}
+
+	public void buildJumpGraph()
+	{
+	}
 }

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

@@ -43,10 +43,26 @@ public class Instructions
 		}
 
 		assert pc == length;
+
+		buildJumpGraph();
+	}
+
+	private void buildJumpGraph()
+	{
+		for (Instruction i : instructions)
+			i.buildJumpGraph();
 	}
 
 	public Code getCode()
 	{
 		return code;
 	}
+
+	public Instruction findInstruction(int pc)
+	{
+		for (Instruction i : instructions)
+			if (i.getPc() == pc)
+				return i;
+		return null;
+	}
 }

src/main/java/info/sigterm/deob/attributes/code/instructions/Branch.java

@@ -20,4 +20,9 @@ public class Branch extends Instruction
 		length += 2;
 	}
 
+	@Override
+	public void buildJumpGraph()
+	{
+		this.addJump(offset);
+	}
 }

src/main/java/info/sigterm/deob/attributes/code/instructions/GotoW.java

@@ -20,4 +20,9 @@ public class GotoW extends Instruction
 		length += 4;
 	}
 
+	@Override
+	public void buildJumpGraph()
+	{
+		this.addJump(offset);
+	}
 }

src/main/java/info/sigterm/deob/attributes/code/instructions/JSR_W.java

@@ -20,4 +20,9 @@ public class JSR_W extends Instruction
 		length += 4;
 	}
 
+	@Override
+	public void buildJumpGraph()
+	{
+		this.addJump(offset);
+	}
 }

src/main/java/info/sigterm/deob/attributes/code/instructions/LookupSwitch.java

@@ -37,4 +37,12 @@ public class LookupSwitch extends Instruction
 
 		length += tableSkip + 8 + (count * 8);
 	}
+
+	@Override
+	public void buildJumpGraph()
+	{
+		for (int i : branch)
+			this.addJump(i);
+		this.addJump(def);
+	}
 }

src/main/java/info/sigterm/deob/attributes/code/instructions/TableSwitch.java

@@ -35,4 +35,12 @@ public class TableSwitch extends Instruction
 
 		length += tableSkip + 12 + (count * 4);
 	}
+
+	@Override
+	public void buildJumpGraph()
+	{
+		for (int i : jumps)
+			this.addJump(i);
+		this.addJump(def);
+	}
 }