svn commit: r1747689 - in /commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic: BranchHandle.java InstructionHandle.java

[sebb]

Author: sebb
Date: Fri Jun 10 12:07:25 2016
New Revision: 1747689

URL: http://svn.apache.org/viewvc?rev=1747689&view=rev
Log:
BCEL-273 - Regressions running FindBugs on BCEL6
Reverted to previous code; added comments

Modified:
    
commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/BranchHandle.java
    
commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/InstructionHandle.java

Modified: 
commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/BranchHandle.java
URL: 
http://svn.apache.org/viewvc/commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/BranchHandle.java?rev=1747689&r1=1747688&r2=1747689&view=diff
==============================================================================
--- 
commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/BranchHandle.java
 (original)
+++ 
commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/BranchHandle.java
 Fri Jun 10 12:07:25 2016
@@ -30,8 +30,14 @@ package org.apache.bcel.generic;
  */
 public final class BranchHandle extends InstructionHandle {
 
+    // This is also a cache in case the InstructionHandle#swapInstruction() 
method is used
+    // See BCEL-273
+    private BranchInstruction bi; // An alias in fact, but saves lots of casts
+
+
     private BranchHandle(final BranchInstruction i) {
         super(i);
+        bi = i;
     }
 
     /** Factory methods.
@@ -58,11 +64,6 @@ public final class BranchHandle extends
         bh_list = this;
     }
 
-    // get the instruction as a BranchInstruction
-    // (do the cast once)
-    private BranchInstruction getBI() {
-        return (BranchInstruction) super.getInstruction();
-    }
 
     /* Override InstructionHandle methods: delegate to branch instruction.
      * Through this overriding all access to the private i_position field 
should
@@ -70,22 +71,22 @@ public final class BranchHandle extends
      */
     @Override
     public int getPosition() {
-        return getBI().getPosition();
+        return bi.getPosition();
     }
 
 
     @Override
     void setPosition( final int pos ) {
         // Original code: i_position = bi.position = pos;
-        getBI().setPosition(pos);
+        bi.setPosition(pos);
         super.setPosition(pos);
     }
 
 
     @Override
     protected int updatePosition( final int offset, final int max_offset ) {
-        int x = getBI().updatePosition(offset, max_offset);
-        super.setPosition(getBI().getPosition());
+        int x = bi.updatePosition(offset, max_offset);
+        super.setPosition(bi.getPosition());
         return x;
     }
 
@@ -94,7 +95,7 @@ public final class BranchHandle extends
      * Pass new target to instruction.
      */
     public void setTarget( final InstructionHandle ih ) {
-        getBI().setTarget(ih);
+        bi.setTarget(ih);
     }
 
 
@@ -102,7 +103,7 @@ public final class BranchHandle extends
      * Update target of instruction.
      */
     public void updateTarget( final InstructionHandle old_ih, final 
InstructionHandle new_ih ) {
-        getBI().updateTarget(old_ih, new_ih);
+        bi.updateTarget(old_ih, new_ih);
     }
 
 
@@ -110,7 +111,7 @@ public final class BranchHandle extends
      * @return target of instruction.
      */
     public InstructionHandle getTarget() {
-        return getBI().getTarget();
+        return bi.getTarget();
     }
 
 
@@ -124,5 +125,6 @@ public final class BranchHandle extends
             throw new ClassGenException("Assigning " + i
                     + " to branch handle which is not a branch instruction");
         }
+        bi = (BranchInstruction) i;
     }
 }

Modified: 
commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/InstructionHandle.java
URL: 
http://svn.apache.org/viewvc/commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/InstructionHandle.java?rev=1747689&r1=1747688&r2=1747689&view=diff
==============================================================================
--- 
commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/InstructionHandle.java
 (original)
+++ 
commons/proper/bcel/trunk/src/main/java/org/apache/bcel/generic/InstructionHandle.java
 Fri Jun 10 12:07:25 2016
@@ -95,7 +95,13 @@ public class InstructionHandle {
      * Temporarily swap the current instruction, without disturbing
      * anything. Meant to be used by a debugger, implementing
      * breakpoints. Current instruction is returned.
+     * <p>
+     * Warning: if this is used on a BranchHandle then some methods such as
+     * getPosition() will still refer to the original cached instruction, 
whereas
+     * other BH methods may affect the cache and the replacement instruction.
      */
+    // See BCEL-273
+    // TODO remove this method in any redesign of BCEL
     public Instruction swapInstruction( final Instruction i ) {
         Instruction oldInstruction = instruction;
         instruction = i;