/*
* fb-contrib - Auxiliary detectors for Java programs
* Copyright (C) 2005-2017 Dave Brosius
*
* 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 com.mebigfatguy.fbcontrib.detect;
import java.util.Set;
import org.apache.bcel.Constants;
import org.apache.bcel.Repository;
import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.JavaClass;
import com.mebigfatguy.fbcontrib.utils.BugType;
import com.mebigfatguy.fbcontrib.utils.FQMethod;
import com.mebigfatguy.fbcontrib.utils.SignatureUtils;
import com.mebigfatguy.fbcontrib.utils.UnmodifiableSet;
import com.mebigfatguy.fbcontrib.utils.Values;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.BytecodeScanningDetector;
import edu.umd.cs.findbugs.OpcodeStack;
import edu.umd.cs.findbugs.OpcodeStack.CustomUserValue;
import edu.umd.cs.findbugs.ba.ClassContext;
/**
* looks for various issues around input/output/streaming library use
*/
@CustomUserValue
public class IOIssues extends BytecodeScanningDetector {
enum IOIUserValue {
BUFFER, READER
};
private static final String ANY_PARMS = "(*)";
private static Set<FQMethod> COPY_METHODS = UnmodifiableSet.create(
//@formatter:off
new FQMethod("java/nio/file/Files", "copy", ANY_PARMS),
new FQMethod("org/apache/commons/io/IOUtils", "copy", ANY_PARMS),
new FQMethod("org/apache/commons/io/IOUtils", "copyLarge", ANY_PARMS),
new FQMethod("org/springframework/util/FileCopyUtils", "copy", ANY_PARMS),
new FQMethod("org/springframework/util/FileCopyUtils", "copyToByteArray", ANY_PARMS),
new FQMethod("com/google/common/io/Files", "copy", ANY_PARMS),
new FQMethod("org/apache/poi/openxml4j/opc/StreamHelper", "copyStream", ANY_PARMS)
//@formatter:on
);
private static final Set<String> BUFFERED_CLASSES = UnmodifiableSet.create(
//@formatter:off
"java.io.BufferedInputStream",
"java.io.BufferedOutputStream",
"java.io.BufferedReader",
"java.io.BufferedWriter"
//@formatter:on
);
private JavaClass readerClass;
private BugReporter bugReporter;
private OpcodeStack stack;
private int clsVersion;
/**
* constructs a IOI detector given the reporter to report bugs on
*
* @param bugReporter
* the sync of bug reports
*/
public IOIssues(BugReporter bugReporter) {
this.bugReporter = bugReporter;
try {
readerClass = Repository.lookupClass("java.io.Reader");
} catch (ClassNotFoundException cnfe) {
bugReporter.reportMissingClass(cnfe);
}
}
/**
* implements the visitor to create and tear down the opcode stack
*
* @param clsContext
* the context object of the currently parsed class
*/
@Override
public void visitClassContext(ClassContext clsContext) {
try {
stack = new OpcodeStack();
clsVersion = clsContext.getJavaClass().getMajor();
super.visitClassContext(clsContext);
} finally {
stack = null;
}
}
/**
* implements the visitor to reset the opcode stack
*
* @param obj
* the currently parsed code block
*/
@Override
public void visitCode(Code obj) {
stack.resetForMethodEntry(this);
super.visitCode(obj);
}
/**
* implements the visitor to look for common api copy utilities to copy streams where the passed in Stream is Buffered. Since these libraries already handle
* the buffering, you are just slowing them down by the extra copy. Also look for copies where the source is a Reader, as this is just wasteful. Can't wrap
* my head around whether a Writer output is sometime valid, might be, so for now ignoring that. Also reports uses of java.io.FileInputStream and
* java.io.FileOutputStream on {@code java >= 1.7} as those classes have finalize methods that junk up gc.
*
* @param seen
* the currently parsed opcode
*/
@Override
public void sawOpcode(int seen) {
IOIUserValue uvSawBuffer = null;
try {
switch (seen) {
case INVOKESPECIAL:
uvSawBuffer = processInvokeSpecial();
break;
case INVOKESTATIC:
processInvokeStatic();
break;
default:
break;
}
} catch (ClassNotFoundException cnfe) {
bugReporter.reportMissingClass(cnfe);
} finally {
stack.sawOpcode(this, seen);
if ((uvSawBuffer != null) && (stack.getStackDepth() > 0)) {
OpcodeStack.Item itm = stack.getStackItem(0);
itm.setUserValue(uvSawBuffer);
}
}
}
private IOIUserValue processInvokeSpecial() throws ClassNotFoundException {
String methodName = getNameConstantOperand();
if (Values.CONSTRUCTOR.equals(methodName)) {
String clsName = getDottedClassConstantOperand();
if (BUFFERED_CLASSES.contains(clsName)) {
return IOIUserValue.BUFFER;
} else if ("java.io.FileInputStream".equals(clsName) || "java.io.FileOutputStream".equals(clsName)) {
if (clsVersion >= Constants.MAJOR_1_7) {
if (!getMethod().isStatic()) {
String sig = getSigConstantOperand();
int numParms = SignatureUtils.getNumParameters(sig);
if (stack.getStackDepth() > numParms) {
OpcodeStack.Item itm = stack.getStackItem(numParms);
if (itm.getRegisterNumber() == 0) {
return null;
}
}
}
bugReporter.reportBug(new BugInstance(this, BugType.IOI_USE_OF_FILE_STREAM_CONSTRUCTORS.name(), NORMAL_PRIORITY).addClass(this)
.addMethod(this).addSourceLine(this));
}
} else if (readerClass != null) {
JavaClass cls = Repository.lookupClass(clsName);
if (cls.instanceOf(readerClass)) {
return IOIUserValue.READER;
}
}
}
return null;
}
private void processInvokeStatic() {
String clsName = getClassConstantOperand();
String methodName = getNameConstantOperand();
FQMethod m = new FQMethod(clsName, methodName, ANY_PARMS);
if (COPY_METHODS.contains(m)) {
String signature = getSigConstantOperand();
int numArguments = SignatureUtils.getNumParameters(signature);
if (stack.getStackDepth() >= numArguments) {
for (int i = 0; i < numArguments; i++) {
OpcodeStack.Item itm = stack.getStackItem(i);
IOIUserValue uv = (IOIUserValue) itm.getUserValue();
if (uv != null) {
switch (uv) {
case BUFFER:
bugReporter.reportBug(new BugInstance(this, BugType.IOI_DOUBLE_BUFFER_COPY.name(), NORMAL_PRIORITY).addClass(this)
.addMethod(this).addSourceLine(this));
break;
case READER:
bugReporter.reportBug(new BugInstance(this, BugType.IOI_COPY_WITH_READER.name(), NORMAL_PRIORITY).addClass(this).addMethod(this)
.addSourceLine(this));
}
break;
}
}
}
}
}
}