From 5770d25e599126c1dac0a0cc45bddbdbe972dfb9 Mon Sep 17 00:00:00 2001
From: "Egor.Ushakov" <egor.ushakov@jetbrains.com>
Date: Wed, 25 Mar 2015 19:12:33 +0300
Subject: [PATCH] decompiler: create less thrown away objects - pt.2

---
 .../java/decompiler/code/ExceptionTable.java     | 15 +++++++++------
 .../decompiler/code/FullInstructionSequence.java |  4 ++--
 .../decompiler/code/InstructionSequence.java     | 16 ++++++++++++----
 .../code/SimpleInstructionSequence.java          |  4 ++--
 4 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/src/org/jetbrains/java/decompiler/code/ExceptionTable.java b/src/org/jetbrains/java/decompiler/code/ExceptionTable.java
index e828a7f..533fa55 100644
--- a/src/org/jetbrains/java/decompiler/code/ExceptionTable.java
+++ b/src/org/jetbrains/java/decompiler/code/ExceptionTable.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2015 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,15 +18,18 @@ package org.jetbrains.java.decompiler.code;
 import org.jetbrains.java.decompiler.code.interpreter.Util;
 import org.jetbrains.java.decompiler.struct.StructContext;
 
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 public class ExceptionTable {
+  public static final ExceptionTable EMPTY = new ExceptionTable(null) {
+    @Override
+    public List<ExceptionHandler> getHandlers() {
+      return Collections.emptyList();
+    }
+  };
 
-  private List<ExceptionHandler> handlers = new ArrayList<ExceptionHandler>();
-
-  public ExceptionTable() {
-  }
+  private final List<ExceptionHandler> handlers;
 
   public ExceptionTable(List<ExceptionHandler> handlers) {
     this.handlers = handlers;
diff --git a/src/org/jetbrains/java/decompiler/code/FullInstructionSequence.java b/src/org/jetbrains/java/decompiler/code/FullInstructionSequence.java
index eb8f819..ae5d4f2 100644
--- a/src/org/jetbrains/java/decompiler/code/FullInstructionSequence.java
+++ b/src/org/jetbrains/java/decompiler/code/FullInstructionSequence.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2015 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,7 +25,7 @@ public class FullInstructionSequence extends InstructionSequence {
   // *****************************************************************************
 
   public FullInstructionSequence(VBStyleCollection<Instruction, Integer> collinstr, ExceptionTable extable) {
-    this.collinstr = collinstr;
+    super(collinstr);
     this.exceptionTable = extable;
 
     // translate raw exception handlers to instr
diff --git a/src/org/jetbrains/java/decompiler/code/InstructionSequence.java b/src/org/jetbrains/java/decompiler/code/InstructionSequence.java
index 709a85d..705db4e 100644
--- a/src/org/jetbrains/java/decompiler/code/InstructionSequence.java
+++ b/src/org/jetbrains/java/decompiler/code/InstructionSequence.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2015 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -34,11 +34,19 @@ public abstract class InstructionSequence {
   // private fields
   // *****************************************************************************
 
-  protected VBStyleCollection<Instruction, Integer> collinstr = new VBStyleCollection<Instruction, Integer>();
+  protected final VBStyleCollection<Instruction, Integer> collinstr;
 
   protected int pointer = 0;
 
-  protected ExceptionTable exceptionTable = new ExceptionTable();
+  protected ExceptionTable exceptionTable = ExceptionTable.EMPTY;
+
+  protected InstructionSequence() {
+    this(new VBStyleCollection<Instruction, Integer>());
+  }
+
+  protected InstructionSequence(VBStyleCollection<Instruction, Integer> collinstr) {
+    this.collinstr = collinstr;
+  }
 
   // *****************************************************************************
   // public methods
@@ -52,7 +60,7 @@ public abstract class InstructionSequence {
   public void clear() {
     collinstr.clear();
     pointer = 0;
-    exceptionTable = new ExceptionTable();
+    exceptionTable = ExceptionTable.EMPTY;
   }
 
   public void addInstruction(Instruction inst, int offset) {
diff --git a/src/org/jetbrains/java/decompiler/code/SimpleInstructionSequence.java b/src/org/jetbrains/java/decompiler/code/SimpleInstructionSequence.java
index bcc3c4a..5963509 100644
--- a/src/org/jetbrains/java/decompiler/code/SimpleInstructionSequence.java
+++ b/src/org/jetbrains/java/decompiler/code/SimpleInstructionSequence.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2015 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,7 @@ public class SimpleInstructionSequence extends InstructionSequence {
   }
 
   public SimpleInstructionSequence(VBStyleCollection<Instruction, Integer> collinstr) {
-    this.collinstr = collinstr;
+    super(collinstr);
   }
 
   public SimpleInstructionSequence clone() {