Author: kohsuke
Date: Mon Dec 26 21:23:49 2005
New Revision: 359174
URL: http://svn.apache.org/viewcvs?rev=359174&view=rev
Log:
fixed a bug in the instrumentation of the null object in the stack
Modified:
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/BcelClassTransformer.java
Modified:
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/BcelClassTransformer.java
URL:
http://svn.apache.org/viewcvs/jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/BcelClassTransformer.java?rev=359174&r1=359173&r2=359174&view=diff
==============================================================================
---
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/BcelClassTransformer.java
(original)
+++
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/BcelClassTransformer.java
Mon Dec 26 21:23:49 2005
@@ -17,6 +17,7 @@
import org.apache.bcel.Constants;
import org.apache.bcel.Repository;
+import org.apache.bcel.classfile.Attribute;
import org.apache.bcel.classfile.ClassFormatException;
import org.apache.bcel.classfile.ClassParser;
import org.apache.bcel.classfile.ConstantCP;
@@ -25,12 +26,10 @@
import org.apache.bcel.classfile.ConstantUtf8;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;
-import org.apache.bcel.classfile.Attribute;
import org.apache.bcel.generic.ACONST_NULL;
import org.apache.bcel.generic.BasicType;
import org.apache.bcel.generic.ClassGen;
import org.apache.bcel.generic.ConstantPoolGen;
-import org.apache.bcel.generic.DUP2_X2;
import org.apache.bcel.generic.GOTO;
import org.apache.bcel.generic.IFEQ;
import org.apache.bcel.generic.IFNULL;
@@ -44,16 +43,14 @@
import org.apache.bcel.generic.InvokeInstruction;
import org.apache.bcel.generic.MethodGen;
import org.apache.bcel.generic.ObjectType;
-import org.apache.bcel.generic.POP;
-import org.apache.bcel.generic.POP2;
import org.apache.bcel.generic.PUSH;
import org.apache.bcel.generic.RET;
import org.apache.bcel.generic.ReferenceType;
import org.apache.bcel.generic.ReturnaddressType;
-import org.apache.bcel.generic.SWAP;
import org.apache.bcel.generic.TABLESWITCH;
import org.apache.bcel.generic.TargetLostException;
import org.apache.bcel.generic.Type;
+import org.apache.bcel.generic.ASTORE;
import org.apache.bcel.verifier.exc.AssertionViolatedException;
import org.apache.commons.javaflow.bytecode.Continuable;
import org.apache.commons.javaflow.bytecode.StackRecorder;
@@ -591,26 +588,33 @@
// check for types with two words on stack
if (type.equals(Type.LONG) || type.equals(Type.DOUBLE)) {
- insList.append(new ACONST_NULL()); // create dummy stack
entry
+ insList.append(InstructionConstants.ACONST_NULL); //
create dummy stack entry
insList.append(loadStackRecorder);
- insList.append(new DUP2_X2()); // swap Stack object and
long/float
- insList.append(new POP2());
+ insList.append(InstructionConstants.DUP2_X2); // swap
Stack object and long/float
+ insList.append(InstructionConstants.POP2);
} else {
insList.append(loadStackRecorder);
- insList.append(new SWAP());
+ insList.append(InstructionConstants.SWAP);
}
insList.append(insFactory.createInvoke(STACK_RECORDER_CLASS,
getPushMethod(type), Type.VOID, new Type[] { type }, Constants.INVOKEVIRTUAL));
if (type.equals(Type.LONG) || type.equals(Type.DOUBLE))
- insList.append(new POP()); // remove dummy stack entry
+ insList.append(InstructionConstants.POP); // remove dummy
stack entry
} else if (type == null) {
insList.append(InstructionConstants.POP);
} else if (type instanceof UninitializedObjectType) {
// After the remove of new, there shouldn't be a
// uninitialized object on the stack
} else if (type instanceof ReferenceType) {
- insList.append(loadStackRecorder);
- insList.append(new SWAP());
- insList.append(insFactory.createInvoke(STACK_RECORDER_CLASS,
getPushMethod(Type.OBJECT), Type.VOID, new Type[] { Type.OBJECT },
Constants.INVOKEVIRTUAL));
+ if(type.equals(Type.NULL)) {
+ // if it's guaranteed to be null, no need to store.
+ // in fact, we can't really store this, because we'll never
+ // be able to restore it as the 'null' type.
+ insList.append(InstructionConstants.POP);
+ } else {
+ insList.append(loadStackRecorder);
+ insList.append(InstructionConstants.SWAP);
+
insList.append(insFactory.createInvoke(STACK_RECORDER_CLASS,
getPushMethod(Type.OBJECT), Type.VOID, new Type[] { Type.OBJECT },
Constants.INVOKEVIRTUAL));
+ }
}
}
// add isCapturing test
@@ -687,18 +691,26 @@
insList.append(insFactory.createInvoke(STACK_RECORDER_CLASS,
getPopMethod(type), type, Type.NO_ARGS, Constants.INVOKEVIRTUAL));
insList.append(InstructionFactory.createStore(type, i));
} else if (type == null) {
- insList.append(new ACONST_NULL());
- insList.append(InstructionFactory.createStore(new
ObjectType("<null object>"), i));
+ insList.append(InstructionConstants.ACONST_NULL);
+ insList.append(new ASTORE(i));
} else if (type instanceof UninitializedObjectType) {
// No uninitilaized objects should be found
// in the local variables.
+ throw new Error("assertion failure");
} else if (type instanceof ReferenceType) {
- insList.append(loadStackRecorder);
- insList.append(insFactory.createInvoke(STACK_RECORDER_CLASS,
getPopMethod(Type.OBJECT), Type.OBJECT, Type.NO_ARGS, Constants.INVOKEVIRTUAL));
- if (!type.equals(Type.OBJECT) && (!type.equals(Type.NULL))) {
- insList.append(insFactory.createCast(Type.OBJECT, type));
+ if (type.equals(Type.NULL)) {
+ // null type is a special type assignable to any type,
+ // whereas popObject returns a java/lang/Object.
+ // the saveFrame method is written so that we don't save
the 'null' object
+ insList.append(InstructionConstants.ACONST_NULL);
+ } else {
+ insList.append(loadStackRecorder);
+
insList.append(insFactory.createInvoke(STACK_RECORDER_CLASS,
getPopMethod(Type.OBJECT), Type.OBJECT, Type.NO_ARGS, Constants.INVOKEVIRTUAL));
+ if (!type.equals(Type.OBJECT)) {
+ insList.append(insFactory.createCast(Type.OBJECT,
type));
+ }
}
- insList.append(InstructionFactory.createStore(type, i));
+ insList.append(new ASTORE(i));
}
}
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