1 files changed, 67 insertions, 21 deletions

diff --git a/src/jdk/nashorn/internal/codegen/CompileUnit.java b/src/jdk/nashorn/internal/codegen/CompileUnit.java
index 73127259..13e9d716 100644
--- a/src/jdk/nashorn/internal/codegen/CompileUnit.java
+++ b/src/jdk/nashorn/internal/codegen/CompileUnit.java
@@ -25,28 +25,77 @@
 
 package jdk.nashorn.internal.codegen;
 
+import java.io.Serializable;
+import java.util.Set;
+import java.util.TreeSet;
+import jdk.nashorn.internal.ir.CompileUnitHolder;
+
 /**
- * Used to track split class compilation.
- */
-public class CompileUnit implements Comparable<CompileUnit> {
+  * Used to track split class compilation. Note that instances of the class are serializable, but all fields are
+  * transient, making the serialized version of the class only useful for tracking the referential topology of other
+  * AST nodes referencing the same or different compile units. We do want to preserve this topology though as
+  * {@link CompileUnitHolder}s in a deserialized AST will undergo reinitialization.
+  */
+public final class CompileUnit implements Comparable<CompileUnit>, Serializable {
+    private static final long serialVersionUID = 1L;
+
     /** Current class name */
-    private final String className;
+    private transient final String className;
 
     /** Current class generator */
-    private ClassEmitter classEmitter;
+    private transient ClassEmitter classEmitter;
 
-    private long weight;
+    private transient long weight;
 
-    private Class<?> clazz;
+    private transient Class<?> clazz;
 
-    CompileUnit(final String className, final ClassEmitter classEmitter) {
-        this(className, classEmitter, 0L);
-    }
+    private transient boolean isUsed;
+
+    private static int emittedUnitCount;
 
     CompileUnit(final String className, final ClassEmitter classEmitter, final long initialWeight) {
         this.className    = className;
-        this.classEmitter = classEmitter;
         this.weight       = initialWeight;
+        this.classEmitter = classEmitter;
+    }
+
+    static Set<CompileUnit> createCompileUnitSet() {
+        return new TreeSet<>();
+    }
+
+    static void increaseEmitCount() {
+        emittedUnitCount++;
+    }
+
+    /**
+     * Get the amount of emitted compile units so far in the system
+     * @return emitted compile unit count
+     */
+    public static int getEmittedUnitCount() {
+        return emittedUnitCount;
+    }
+
+    /**
+     * Check if this compile unit is used
+     * @return true if tagged as in use - i.e active code that needs to be generated
+     */
+    public boolean isUsed() {
+        return isUsed;
+    }
+
+    /**
+     * Check if a compile unit has code, not counting inits and clinits
+     * @return true of if there is "real code" in the compile unit
+     */
+    public boolean hasCode() {
+        return (classEmitter.getMethodCount() - classEmitter.getInitCount() - classEmitter.getClinitCount()) > 0;
+    }
+
+    /**
+     * Tag this compile unit as used
+     */
+    public void setUsed() {
+        this.isUsed = true;
     }
 
     /**
@@ -80,14 +129,6 @@ public class CompileUnit implements Comparable<CompileUnit> {
     }
 
     /**
-     * Get the current weight of the compile unit.
-     * @return the unit's weight
-     */
-    long getWeight() {
-        return weight;
-    }
-
-    /**
      * Check if this compile unit can hold {@code weight} more units of weight
      * @param w weight to check if can be added
      * @return true if weight fits in this compile unit
@@ -112,13 +153,18 @@ public class CompileUnit implements Comparable<CompileUnit> {
         return className;
     }
 
+    private static String shortName(final String name) {
+        return name == null ? null : name.lastIndexOf('/') == -1 ? name : name.substring(name.lastIndexOf('/') + 1);
+    }
+
     @Override
     public String toString() {
-        return "[classname=" + className + " weight=" + weight + '/' + Splitter.SPLIT_THRESHOLD + ']';
+        final String methods = classEmitter != null ? classEmitter.getMethodNames().toString() : "<anon>";
+        return "[CompileUnit className=" + shortName(className) + " weight=" + weight + '/' + Splitter.SPLIT_THRESHOLD + " hasCode=" + methods + ']';
     }
 
     @Override
-    public int compareTo(CompileUnit o) {
+    public int compareTo(final CompileUnit o) {
         return className.compareTo(o.className);
     }
 }