store references to instruction copies

inside instruction

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/AbstractJumpInstruction.java

@@ -51,10 +51,14 @@ public abstract class AbstractJumpInstruction extends InstructionImpl {
         this.resolvedTarget = outgoingEdgeTo(resolvedTarget);
     }
 
-    abstract AbstractJumpInstruction copy(@NotNull Label newLabel);
+    protected abstract AbstractJumpInstruction createCopy(@NotNull Label newLabel);
+
+    final public Instruction copy(@NotNull Label newLabel) {
+        return updateCopyInfo(createCopy(newLabel));
+    }
 
     @Override
-    public Instruction copy() {
-        return copy(targetLabel);
+    protected Instruction createCopy() {
+        return createCopy(targetLabel);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/ConditionalJumpInstruction.java

@@ -73,7 +73,7 @@ public class ConditionalJumpInstruction extends AbstractJumpInstruction {
     }
 
     @Override
-    AbstractJumpInstruction copy(@NotNull Label newLabel) {
+    protected AbstractJumpInstruction createCopy(@NotNull Label newLabel) {
         return new ConditionalJumpInstruction(onTrue, newLabel);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/Instruction.java

@@ -36,4 +36,7 @@ public interface Instruction {
     Collection<Instruction> getNextInstructions();
 
     void accept(InstructionVisitor visitor);
+
+    @NotNull
+    Collection<Instruction> getCopies();
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/InstructionImpl.java

@@ -16,6 +16,7 @@
 
 package org.jetbrains.jet.lang.cfg.pseudocode;
 
+import com.google.common.collect.Sets;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -28,6 +29,7 @@ import java.util.LinkedHashSet;
 public abstract class InstructionImpl implements Instruction {
     private Pseudocode owner;
     private final Collection<Instruction> previousInstructions = new LinkedHashSet<Instruction>();
+    private final Collection<Instruction> copies = Sets.newHashSet();
     protected boolean isDead = false;
 
     protected InstructionImpl() {
@@ -67,5 +69,29 @@ public abstract class InstructionImpl implements Instruction {
         return isDead;
     }
 
-    public abstract Instruction copy();
+    public final Instruction copy() {
+        return updateCopyInfo(createCopy());
+    }
+
+    protected abstract Instruction createCopy();
+
+    @NotNull
+    @Override
+    public Collection<Instruction> getCopies() {
+        return copies;
+    }
+
+    private void addCopy(@NotNull Instruction instruction) {
+        copies.add(instruction);
+    }
+
+    protected Instruction updateCopyInfo(@NotNull Instruction instruction) {
+        for (Instruction copy : copies) {
+            ((InstructionImpl)copy).addCopy(instruction);
+            ((InstructionImpl)instruction).addCopy(copy);
+        }
+        addCopy(instruction);
+        ((InstructionImpl)instruction).addCopy(this);
+        return instruction;
+    }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/LocalDeclarationInstruction.java

@@ -73,7 +73,7 @@ public class LocalDeclarationInstruction extends InstructionWithNext {
     }
 
     @Override
-    public Instruction copy() {
+    protected Instruction createCopy() {
         return new LocalDeclarationInstruction((JetDeclaration) element, body);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/NondeterministicJumpInstruction.java

@@ -69,7 +69,7 @@ public class NondeterministicJumpInstruction extends InstructionImpl{
     @NotNull
     @Override
     public Collection<Instruction> getNextInstructions() {
-        ArrayList<Instruction> targetInstructions = Lists.newArrayList(getResolvedTargets().values());
+        List<Instruction> targetInstructions = Lists.newArrayList(getResolvedTargets().values());
         targetInstructions.add(getNext());
         return targetInstructions;
     }
@@ -90,7 +90,16 @@ public class NondeterministicJumpInstruction extends InstructionImpl{
     }
 
     @Override
-    public Instruction copy() {
-        return new NondeterministicJumpInstruction(getTargetLabels());
+    protected Instruction createCopy() {
+        return createCopy(getTargetLabels());
+    }
+
+    @NotNull
+    public final Instruction copy(@NotNull List<Label> newTargetLabels) {
+        return updateCopyInfo(createCopy(newTargetLabels));
+    }
+
+    private Instruction createCopy(@NotNull List<Label> newTargetLabels) {
+        return new NondeterministicJumpInstruction(newTargetLabels);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/ReadUnitValueInstruction.java

@@ -39,7 +39,7 @@ public class ReadUnitValueInstruction extends InstructionWithNext {
     }
 
     @Override
-    public Instruction copy() {
+    protected Instruction createCopy() {
         return new ReadUnitValueInstruction((JetExpression) element);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/ReadValueInstruction.java

@@ -39,7 +39,7 @@ public class ReadValueInstruction extends InstructionWithNext {
     }
 
     @Override
-    public Instruction copy() {
+    protected Instruction createCopy() {
         return new ReadValueInstruction(element);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/ReturnNoValueInstruction.java

@@ -49,7 +49,7 @@ public class ReturnNoValueInstruction extends AbstractJumpInstruction implements
     }
 
     @Override
-    AbstractJumpInstruction copy(@NotNull Label newLabel) {
+    protected AbstractJumpInstruction createCopy(@NotNull Label newLabel) {
         return new ReturnNoValueInstruction(element, newLabel);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/ReturnValueInstruction.java

@@ -50,7 +50,7 @@ public class ReturnValueInstruction extends AbstractJumpInstruction implements J
     }
 
     @Override
-    AbstractJumpInstruction copy(@NotNull Label newLabel) {
+    protected AbstractJumpInstruction createCopy(@NotNull Label newLabel) {
         return new ReturnValueInstruction((JetExpression) element, newLabel);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/SubroutineEnterInstruction.java

@@ -45,7 +45,7 @@ public class SubroutineEnterInstruction extends InstructionWithNext {
     }
 
     @Override
-    public Instruction copy() {
+    protected Instruction createCopy() {
         return new SubroutineEnterInstruction(subroutine);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/SubroutineExitInstruction.java

@@ -61,7 +61,7 @@ public class SubroutineExitInstruction extends InstructionImpl {
     }
 
     @Override
-    public Instruction copy() {
+    protected Instruction createCopy() {
         return new SubroutineExitInstruction(subroutine, debugLabel);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/SubroutineSinkInstruction.java

@@ -55,7 +55,7 @@ public class SubroutineSinkInstruction extends InstructionImpl {
     }
 
     @Override
-    public Instruction copy() {
+    protected Instruction createCopy() {
         return new SubroutineSinkInstruction(subroutine, debugLabel);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/UnconditionalJumpInstruction.java

@@ -40,7 +40,7 @@ public class UnconditionalJumpInstruction extends AbstractJumpInstruction {
     }
 
     @Override
-    AbstractJumpInstruction copy(@NotNull Label newLabel) {
+    protected AbstractJumpInstruction createCopy(@NotNull Label newLabel) {
         return new UnconditionalJumpInstruction(newLabel);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/UnsupportedElementInstruction.java

@@ -39,7 +39,7 @@ public class UnsupportedElementInstruction extends InstructionWithNext {
     }
 
     @Override
-    public Instruction copy() {
+    protected Instruction createCopy() {
         return new UnsupportedElementInstruction(element);
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/VariableDeclarationInstruction.java

@@ -49,7 +49,7 @@ public class VariableDeclarationInstruction extends InstructionWithNext {
     }
 
     @Override
-    public Instruction copy() {
+    protected Instruction createCopy() {
         if (element instanceof JetParameter) {
             return new VariableDeclarationInstruction((JetParameter) element);
         }

compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/WriteValueInstruction.java

@@ -52,7 +52,7 @@ public class WriteValueInstruction extends InstructionWithNext {
     }
 
     @Override
-    public Instruction copy() {
+    protected Instruction createCopy() {
         return new WriteValueInstruction(element, lValue);
     }
 }