Author: kohsuke
Date: Wed Dec 28 14:53:35 2005
New Revision: 359657
URL: http://svn.apache.org/viewcvs?rev=359657&view=rev
Log:
improved the readability by introducing a class that represents an execution
sequence.
previously it was represented as an ArrayList, and therefore it was harder to
understand
what it was doing, and slower, because it involved a lot of cloning.
Added:
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ExecutionPath.java
(with props)
Modified:
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/BcelClassTransformer.java
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ControlFlowGraph.java
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/InstructionContext.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=359657&r1=359656&r2=359657&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
Wed Dec 28 14:53:35 2005
@@ -57,6 +57,7 @@
import org.apache.commons.javaflow.bytecode.transformation.ResourceTransformer;
import
org.apache.commons.javaflow.bytecode.transformation.bcel.analyser.ControlFlowGraph;
import
org.apache.commons.javaflow.bytecode.transformation.bcel.analyser.ExceptionHandler;
+import
org.apache.commons.javaflow.bytecode.transformation.bcel.analyser.ExecutionPath;
import
org.apache.commons.javaflow.bytecode.transformation.bcel.analyser.ExecutionVisitor;
import org.apache.commons.javaflow.bytecode.transformation.bcel.analyser.Frame;
import
org.apache.commons.javaflow.bytecode.transformation.bcel.analyser.InstructionContext;
@@ -70,7 +71,6 @@
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
-import java.util.ArrayList;
import java.util.Vector;
@@ -198,7 +198,6 @@
// information about every instruction
final ControlFlowGraph cfg = new ControlFlowGraph(method);
- //analyse(clazz, method, cfg, icv, ev);
analyse(clazzGen, method, cfg, ev);
try {
@@ -286,55 +285,26 @@
}
}
- //private void analyse(ClassGen clazz, MethodGen method, ControlFlowGraph
cfg, InstConstraintVisitor icv, ExecutionVisitor ev) {
private void analyse(ClassGen clazz, MethodGen method, ControlFlowGraph
cfg, ExecutionVisitor ev) {
log.debug("analyse " + method.getName());
- // build the initial frame situation for this method.
- final Frame vanillaFrame = new Frame(method.getMaxLocals(),
method.getMaxStack());
- if (!method.isStatic()) {
- if (method.getName().equals(Constants.CONSTRUCTOR_NAME)) {
- Frame._this = new UninitializedObjectType(new
ObjectType(clazz.getClassName()));
- vanillaFrame.getLocals().set(0, new
UninitializedObjectType(new ObjectType(clazz.getClassName())));
- } else {
- Frame._this = null;
- vanillaFrame.getLocals().set(0, new
ObjectType(clazz.getClassName()));
- }
- }
- // fill local variables with parameter types
- final Type[] argtypes = method.getArgumentTypes();
- int twoslotoffset = 0;
- for (int j = 0; j < argtypes.length; j++) {
- if ((argtypes[j] == Type.SHORT) || (argtypes[j] == Type.BYTE) ||
(argtypes[j] == Type.CHAR) || (argtypes[j] == Type.BOOLEAN)) {
- argtypes[j] = Type.INT;
- }
- vanillaFrame.getLocals().set(twoslotoffset + j +
(method.isStatic() ? 0 : 1), argtypes[j]);
- if (argtypes[j].getSize() == 2) {
- twoslotoffset++;
- vanillaFrame.getLocals().set(twoslotoffset + j +
(method.isStatic() ? 0 : 1), Type.UNKNOWN);
- }
- }
- //icv.setMethodGen(method);
+ final Frame vanillaFrame = craeteInitialFrame(method, clazz);
final Vector ics = new Vector(); // Type: InstructionContext
- final Vector ecs = new Vector(); // Type: ArrayList (of
InstructionContext)
+ final Vector ecs = new Vector(); // Type: ExecutionPath
final InstructionContext start =
cfg.contextOf(method.getInstructionList().getStart());
- //start.execute(vanillaFrame, new ArrayList(), icv, ev);
- start.execute(vanillaFrame, new ArrayList(), ev);
+ start.execute(vanillaFrame, ExecutionPath.EMPTY, ev);
// new ArrayList() <=> no Instruction was executed before
// => Top-Level routine (no jsr call before)
ics.add(start);
- ecs.add(new ArrayList());
+ ecs.add(ExecutionPath.EMPTY);
while (!ics.isEmpty()) {
final InstructionContext u = (InstructionContext) ics.remove(0);
- final ArrayList ec = (ArrayList) ecs.remove(0);
-
- final ArrayList oldchain = (ArrayList) (ec.clone());
- final ArrayList newchain = (ArrayList) (ec.clone());
- newchain.add(u);
+ final ExecutionPath oldchain = (ExecutionPath) ecs.remove(0);
+ final ExecutionPath newchain = oldchain.append(u);
if ((u.getInstruction().getInstruction()) instanceof RET) {
// We can only follow _one_ successor, the one after the
@@ -346,7 +316,7 @@
//if (theSuccessor.execute(u.getOutFrame(oldchain), newchain,
icv, ev)) {
if (theSuccessor.execute(u.getOutFrame(oldchain), newchain,
ev)) {
ics.add(theSuccessor);
- ecs.add(newchain.clone());
+ ecs.add(newchain);
}
} else { // "not a ret"
// Normal successors. Add them to the queue of successors.
@@ -356,7 +326,7 @@
//if (v.execute(u.getOutFrame(oldchain), newchain, icv,
ev)) {
if (v.execute(u.getOutFrame(oldchain), newchain, ev)) {
ics.add(v);
- ecs.add(newchain.clone());
+ ecs.add(newchain);
}
}
}
@@ -379,15 +349,46 @@
.getExceptionType()));
final Frame newFrame = new Frame(newLocals, newStack);
- //if (v.execute(newFrame, new ArrayList(), icv, ev)) {
- if (v.execute(newFrame, new ArrayList(), ev)) {
+ if (v.execute(newFrame, ExecutionPath.EMPTY, ev)) {
ics.add(v);
- ecs.add(new ArrayList());
+ ecs.add(ExecutionPath.EMPTY);
}
}
}
}
+ /**
+ * Creates a [EMAIL PROTECTED] Frame} object that represents the state of
the stack frame
+ * at the beginning of a method.
+ */
+ private Frame craeteInitialFrame(MethodGen method, ClassGen clazz) {
+ final Frame vanillaFrame = new Frame(method.getMaxLocals(),
method.getMaxStack());
+ if (!method.isStatic()) {
+ if (method.getName().equals(Constants.CONSTRUCTOR_NAME)) {
+ Frame._this = new UninitializedObjectType(new
ObjectType(clazz.getClassName()));
+ vanillaFrame.getLocals().set(0, new
UninitializedObjectType(new ObjectType(clazz.getClassName())));
+ } else {
+ Frame._this = null;
+ vanillaFrame.getLocals().set(0, new
ObjectType(clazz.getClassName()));
+ }
+ }
+ // fill local variables with parameter types
+ final Type[] argtypes = method.getArgumentTypes();
+ int twoslotoffset = 0;
+ for (int j = 0; j < argtypes.length; j++) {
+ if ((argtypes[j] == Type.SHORT) || (argtypes[j] == Type.BYTE) ||
(argtypes[j] == Type.CHAR) || (argtypes[j] == Type.BOOLEAN)) {
+ argtypes[j] = Type.INT;
+ }
+ vanillaFrame.getLocals().set(twoslotoffset + j +
(method.isStatic() ? 0 : 1), argtypes[j]);
+ if (argtypes[j].getSize() == 2) {
+ twoslotoffset++;
+ vanillaFrame.getLocals().set(twoslotoffset + j +
(method.isStatic() ? 0 : 1), Type.UNKNOWN);
+ }
+ }
+
+ return vanillaFrame;
+ }
+
private void rewrite(MethodGen method, ControlFlowGraph cfg) throws
ClassNotFoundException {
final InstructionFactory insFactory = new
InstructionFactory(method.getConstantPool());
final Vector invokeIns = new Vector();
@@ -409,7 +410,7 @@
Frame frame = null;
try {
context = cfg.contextOf(ins);
- frame = context.getOutFrame(new ArrayList());
+ frame = context.getOutFrame(ExecutionPath.EMPTY);
} catch (AssertionViolatedException ave) {
// empty
}
@@ -435,7 +436,7 @@
// remove additional dup's
while (next != null &&
next.getInstruction().getOpcode() == Constants.DUP) {
context = cfg.contextOf(next);
- context.getOutFrame(new ArrayList());
+ context.getOutFrame(ExecutionPath.EMPTY);
final InstructionHandle newnext = next.getNext();
insList.delete(next);
next = newnext;
Modified:
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ControlFlowGraph.java
URL:
http://svn.apache.org/viewcvs/jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ControlFlowGraph.java?rev=359657&r1=359656&r2=359657&view=diff
==============================================================================
---
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ControlFlowGraph.java
(original)
+++
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ControlFlowGraph.java
Wed Dec 28 14:53:35 2005
@@ -65,10 +65,10 @@
private HashMap outFrames; // key: the last-executed JSR
/**
- * The 'execution predecessors' - a list of type
InstructionContext
+ * The 'execution predecessors' - a list of [EMAIL PROTECTED]
InstructionContext}
* of those instances that have been execute()d before in that
order.
*/
- private ArrayList executionPredecessors = null; // Type:
InstructionContext
+ private ExecutionPath executionPredecessors = null; // Type:
InstructionContext
/**
* Creates an InstructionHandleImpl object from an
InstructionHandle.
@@ -92,7 +92,7 @@
/**
* Returns a clone of the "outgoing" frame situation with
respect to the given ExecutionChain.
*/
- public Frame getOutFrame(ArrayList execChain){
+ public Frame getOutFrame(ExecutionPath execChain){
executionPredecessors = execChain;
Frame org;
@@ -126,7 +126,7 @@
* and therefore calculates the "outgoing" frame situation.
* Returns: True iff the "incoming" frame situation changed
after
* merging with "inFrame".
- * The execPreds ArrayList must contain the InstructionContext
+ * The execPreds contain the InstructionContext
* objects executed so far in the correct order. This is just
* one execution path [out of many]. This is needed to correctly
* "merge" in the special case of a RET's successor.
@@ -135,9 +135,12 @@
* @return true - if and only if the "outgoing" frame situation
* changed from the one before execute()ing.
*/
- public boolean execute(Frame inFrame, ArrayList execPreds,
ExecutionVisitor ev){
+ public boolean execute(Frame inFrame, ExecutionPath execPreds,
ExecutionVisitor ev){
- executionPredecessors = (ArrayList) execPreds.clone();
+ // When merge failed, this is useful to see what are two passes
+ ExecutionPath oldExecPreds = executionPredecessors;
+
+ executionPredecessors = execPreds;
//sanity check
if ( (lastExecutionJSR() == null) &&
(subroutines.subroutineOf(getInstruction()) != subroutines.getTopLevel() ) ){
@@ -219,15 +222,11 @@
/**
* Returns the control flow execution chain. This is built
- * while execute(Frame, ArrayList)-ing the code represented
+ * while [EMAIL PROTECTED] #execute(Frame, ExecutionPath,
ExecutionVisitor) executing} the code represented
* by the surrounding ControlFlowGraph.
*/
private String getExecutionChain(){
- String s = this.toString();
- for (int i=executionPredecessors.size()-1; i>=0; i--){
- s = executionPredecessors.get(i)+"\n" + s;
- }
- return s;
+ return executionPredecessors.toString()+"\n"+this.toString();
}
@@ -248,28 +247,8 @@
return instruction;
}
- /**
- * Returns the InstructionContextImpl with an JSR/JSR_W
- * that was last in the ExecutionChain, without
- * a corresponding RET, i.e.
- * we were called by this one.
- * Returns null if we were called from the top level.
- */
- private InstructionContextImpl lastExecutionJSR(){
-
- int size = executionPredecessors.size();
- int retcount = 0;
-
- for (int i=size-1; i>=0; i--){
- InstructionContextImpl current =
(InstructionContextImpl) (executionPredecessors.get(i));
- Instruction currentlast =
current.getInstruction().getInstruction();
- if (currentlast instanceof RET) retcount++;
- if (currentlast instanceof JsrInstruction){
- retcount--;
- if (retcount == -1) return current;
- }
- }
- return null;
+ private InstructionContext lastExecutionJSR(){
+ return executionPredecessors.lastExecutionJSR();
}
/* Satisfies InstructionContext.getSuccessors(). */
Added:
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ExecutionPath.java
URL:
http://svn.apache.org/viewcvs/jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ExecutionPath.java?rev=359657&view=auto
==============================================================================
---
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ExecutionPath.java
(added)
+++
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ExecutionPath.java
Wed Dec 28 14:53:35 2005
@@ -0,0 +1,72 @@
+package org.apache.commons.javaflow.bytecode.transformation.bcel.analyser;
+
+import org.apache.bcel.generic.Instruction;
+import org.apache.bcel.generic.RET;
+import org.apache.bcel.generic.JsrInstruction;
+
+/**
+ * List of [EMAIL PROTECTED] InstructionContext} that represents a sequence of
an execution.
+ *
+ * <p>
+ * This object is immutable.
+ * The sequence is represented in left-associative style; that is,
+ * a sequence of [a,b,c,d] is represented as prev=[a,b,c] and last=d.
+ *
+ * @author Kohsuke Kawaguchi
+ */
+public final class ExecutionPath {
+ /**
+ * Singleton [EMAIL PROTECTED] ExecutionPath} that represents an empty
sequence [].
+ */
+ public static final ExecutionPath EMPTY = new ExecutionPath(null,null);
+
+ private final ExecutionPath prev;
+ private final InstructionContext last;
+
+ private ExecutionPath(ExecutionPath prev, InstructionContext last) {
+ this.prev = prev;
+ this.last = last;
+ }
+
+ /**
+ * Creates a new [EMAIL PROTECTED] ExecutionPath} that has
+ * <tt>[... list in this ExecutionPath ..., ins]</tt>.
+ */
+ public ExecutionPath append(InstructionContext ins) {
+ return new ExecutionPath(this,ins);
+ }
+
+ /**
+ * Returns the InstructionContextImpl with an JSR/JSR_W
+ * that was last in the ExecutionChain, without
+ * a corresponding RET, i.e.
+ * we were called by this one.
+ * Returns null if we were called from the top level.
+ */
+ public InstructionContext lastExecutionJSR(){
+ int retcount = 0;
+
+ for( ExecutionPath ptr = this; ptr!=EMPTY; ptr=ptr.prev) {
+ Instruction i = ptr.last.getInstruction().getInstruction();
+ if (i instanceof RET) retcount++;
+ if (i instanceof JsrInstruction){
+ retcount--;
+ if (retcount == -1)
+ return ptr.last;
+ }
+ }
+
+ return null;
+ }
+
+ /**
+ * Returns a human readable representation.
+ */
+ public String toString() {
+ if(this==EMPTY)
+ return "";
+ else {
+ return prev.toString()+"\n"+last.toString();
+ }
+ }
+}
Propchange:
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/ExecutionPath.java
------------------------------------------------------------------------------
svn:eol-style = native
Modified:
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/InstructionContext.java
URL:
http://svn.apache.org/viewcvs/jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/InstructionContext.java?rev=359657&r1=359656&r2=359657&view=diff
==============================================================================
---
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/InstructionContext.java
(original)
+++
jakarta/commons/sandbox/javaflow/trunk/src/java/org/apache/commons/javaflow/bytecode/transformation/bcel/analyser/InstructionContext.java
Wed Dec 28 14:53:35 2005
@@ -51,7 +51,7 @@
* @return true - if and only if the "outgoing" frame situation
* changed from the one before execute()ing.
*/
- boolean execute(Frame inFrame, ArrayList executionPredecessors,
ExecutionVisitor ev);
+ boolean execute(Frame inFrame, ExecutionPath executionPredecessors,
ExecutionVisitor ev);
Frame getInFrame();
@@ -60,9 +60,9 @@
* therefore <B>it has to be calculated by execute(Frame, ArrayList)
* first.</B>
*
- * @see #execute(Frame, ArrayList, ExecutionVisitor)
+ * @see #execute(Frame, ExecutionPath, ExecutionVisitor)
*/
- Frame getOutFrame(ArrayList executionPredecessors);
+ Frame getOutFrame(ExecutionPath executionPredecessors);
/**
* Returns the InstructionHandle this InstructionContext is wrapped
around.
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