/*
* FindBugs - Find bugs in Java programs
* Copyright (C) 2003,2004 University of Maryland
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.umd.cs.findbugs;
import java.util.Iterator;
import java.util.LinkedList;
import org.apache.bcel.generic.InstructionHandle;
import edu.umd.cs.findbugs.ba.BasicBlock;
import edu.umd.cs.findbugs.ba.Edge;
/**
* Drive an InstructionScannerGenerator over the instructions of a simple path.
* The generator will create scanners at certain instructions. Each instruction
* and edge is fed to all scanners so created.
*/
public class InstructionScannerDriver {
private final Iterator<Edge> edgeIter;
private final LinkedList<InstructionScanner> scannerList;
private static final boolean DEBUG = SystemProperties.getBoolean("isd.debug");
/**
* Constructor.
*
* @param edgeIter
* iterator over Edges specifying path to be scanned
*/
public InstructionScannerDriver(Iterator<Edge> edgeIter) {
this.edgeIter = edgeIter;
scannerList = new LinkedList<InstructionScanner>();
}
/**
* Execute by driving the InstructionScannerGenerator over all instructions.
* Each generated InstructionScanner is driven over all instructions and
* edges.
*
* @param generator
* the InstructionScannerGenerator
*/
public void execute(InstructionScannerGenerator generator) {
// Pump the instructions in the path through the generator and all
// generated scanners
while (edgeIter.hasNext()) {
Edge edge = edgeIter.next();
BasicBlock source = edge.getSource();
if (DEBUG) {
System.out.println("ISD: scanning instructions in block " + source.getLabel());
}
// Traverse all instructions in the source block
Iterator<InstructionHandle> i = source.instructionIterator();
int count = 0;
while (i.hasNext()) {
InstructionHandle handle = i.next();
// Check if the generator wants to create a new scanner
if (generator.start(handle)) {
scannerList.add(generator.createScanner());
}
// Pump the instruction into all scanners
for (InstructionScanner scanner : scannerList) {
scanner.scanInstruction(handle);
}
++count;
}
if (DEBUG) {
System.out.println("ISD: scanned " + count + " instructions");
}
// Now that we've finished the source block, pump the edge
// into all scanners
for (InstructionScanner scanner : scannerList) {
scanner.traverseEdge(edge);
}
}
}
}