/*
* FindBugs - Find bugs in Java programs
* Copyright (C) 2004 Dave Brosius <dbrosius@users.sourceforge.net>
* Copyright (C) 2003-2006 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.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.util.ArrayList;
import java.util.BitSet;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.annotation.CheckForNull;
import javax.annotation.meta.TypeQualifier;
import org.apache.bcel.Repository;
import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.CodeException;
import org.apache.bcel.classfile.Constant;
import org.apache.bcel.classfile.ConstantClass;
import org.apache.bcel.classfile.ConstantDouble;
import org.apache.bcel.classfile.ConstantFloat;
import org.apache.bcel.classfile.ConstantInteger;
import org.apache.bcel.classfile.ConstantLong;
import org.apache.bcel.classfile.ConstantString;
import org.apache.bcel.classfile.ConstantUtf8;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.LocalVariable;
import org.apache.bcel.classfile.LocalVariableTable;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.BasicType;
import org.apache.bcel.generic.Type;
import edu.umd.cs.findbugs.OpcodeStack.Item.SpecialKind;
import edu.umd.cs.findbugs.StackMapAnalyzer.JumpInfoFromStackMap;
import edu.umd.cs.findbugs.ba.AnalysisContext;
import edu.umd.cs.findbugs.ba.AnalysisFeatures;
import edu.umd.cs.findbugs.ba.ClassMember;
import edu.umd.cs.findbugs.ba.FieldSummary;
import edu.umd.cs.findbugs.ba.XFactory;
import edu.umd.cs.findbugs.ba.XField;
import edu.umd.cs.findbugs.ba.XMethod;
import edu.umd.cs.findbugs.ba.ch.Subtypes2;
import edu.umd.cs.findbugs.bcel.OpcodeStackDetector;
import edu.umd.cs.findbugs.classfile.CheckedAnalysisException;
import edu.umd.cs.findbugs.classfile.DescriptorFactory;
import edu.umd.cs.findbugs.classfile.Global;
import edu.umd.cs.findbugs.classfile.IAnalysisCache;
import edu.umd.cs.findbugs.classfile.MethodDescriptor;
import edu.umd.cs.findbugs.classfile.analysis.MethodInfo;
import edu.umd.cs.findbugs.internalAnnotations.SlashedClassName;
import edu.umd.cs.findbugs.util.ClassName;
import edu.umd.cs.findbugs.util.Util;
import edu.umd.cs.findbugs.visitclass.Constants2;
import edu.umd.cs.findbugs.visitclass.DismantleBytecode;
import edu.umd.cs.findbugs.visitclass.LVTHelper;
import edu.umd.cs.findbugs.visitclass.PreorderVisitor;
/**
* tracks the types and numbers of objects that are currently on the operand
* stack throughout the execution of method. To use, a detector should
* instantiate one for each method, and call
* <p>
* stack.sawOpcode(this,seen);
* </p>
* at the bottom of their sawOpcode method. at any point you can then inspect
* the stack and see what the types of objects are on the stack, including
* constant values if they were pushed. The types described are of course, only
* the static types. There are some outstanding opcodes that have yet to be
* implemented, I couldn't find any code that actually generated these, so i
* didn't put them in because I couldn't test them:
* <ul>
* <li>dup2_x2</li>
* <li>jsr_w</li>
* <li>wide</li>
* </ul>
*/
public class OpcodeStack implements Constants2 {
/** You can put this annotation on a OpcodeStack detector
* to indicate that it uses {@link OpcodeStack.Item#userValue},
* and thus should not reuse generic OpcodeStack information
* from an iterative evaluation of the opcode stack. Such detectors
* will not use iterative opcode stack evaluation.
*
* This is primarily for detectors that need to be backwards compatible with
* versions of FindBugs that do not support {@link edu.umd.cs.findbugs.bcel.OpcodeStackDetector.WithCustomJumpInfo }}
*/
@Documented
@Target({ElementType.TYPE, ElementType.PACKAGE})
@Retention(RetentionPolicy.RUNTIME)
public @interface CustomUserValue {
}
/**
*
*/
private static final String JAVA_UTIL_ARRAYS_ARRAY_LIST = "Ljava/util/Arrays$ArrayList;";
private static final boolean DEBUG = SystemProperties.getBoolean("ocstack.debug");
private static final boolean DEBUG2 = DEBUG;
private List<Item> stack;
private List<Item> lvValues;
private final List<Integer> lastUpdate;
private boolean top;
static class HttpParameterInjection {
HttpParameterInjection(String parameterName, int pc) {
this.parameterName = parameterName;
this.pc = pc;
}
String parameterName;
int pc;
}
private boolean seenTransferOfControl = false;
private final boolean useIterativeAnalysis = AnalysisContext.currentAnalysisContext().getBoolProperty(
AnalysisFeatures.INTERATIVE_OPCODE_STACK_ANALYSIS);
public static class Item {
@Documented
@TypeQualifier(applicableTo = Integer.class)
@Retention(RetentionPolicy.RUNTIME)
public @interface SpecialKind {
}
static @SpecialKind int asSpecialKind(int kind) {
return kind;
}
public static final @SpecialKind
int NOT_SPECIAL = 0;
public static final @SpecialKind
int SIGNED_BYTE = 1;
public static final @SpecialKind
int RANDOM_INT = 2;
public static final @SpecialKind
int LOW_8_BITS_CLEAR = 3;
public static final @SpecialKind
int HASHCODE_INT = 4;
public static final @SpecialKind
int INTEGER_SUM = 5;
public static final @SpecialKind
int AVERAGE_COMPUTED_USING_DIVISION = 6;
public static final @SpecialKind
int FLOAT_MATH = 7;
public static final @SpecialKind
int RANDOM_INT_REMAINDER = 8;
public static final @SpecialKind
int HASHCODE_INT_REMAINDER = 9;
public static final @SpecialKind
int FILE_SEPARATOR_STRING = 10;
public static final @SpecialKind
int MATH_ABS = 11;
public static final @SpecialKind
int MATH_ABS_OF_RANDOM = 12;
public static final @SpecialKind
int MATH_ABS_OF_HASHCODE = 13;
public static final @SpecialKind
int NON_NEGATIVE = 14;
public static final @SpecialKind
int NASTY_FLOAT_MATH = 15;
public static final @SpecialKind
int FILE_OPENED_IN_APPEND_MODE = 16;
public static final @SpecialKind
int SERVLET_REQUEST_TAINTED = 17;
public static final @SpecialKind
int NEWLY_ALLOCATED = 18;
public static final @SpecialKind
int ZERO_MEANS_NULL = 19;
public static final @SpecialKind
int NONZERO_MEANS_NULL = 20;
public static final @SpecialKind
int RESULT_OF_I2L = 21;
public static final @SpecialKind
int RESULT_OF_L2I = 22;
public static final @SpecialKind
int SERVLET_OUTPUT = 23;
public static final @SpecialKind
int TYPE_ONLY = 24;
@edu.umd.cs.findbugs.internalAnnotations.StaticConstant
public static final HashMap<Integer, String> specialKindNames = new HashMap<Integer, String>();
private static @SpecialKind int nextSpecialKind = asSpecialKind(TYPE_ONLY + 1);
public static @SpecialKind
int defineNewSpecialKind(String name) {
specialKindNames.put(nextSpecialKind, name);
@SpecialKind int result = asSpecialKind( nextSpecialKind+1);
nextSpecialKind = result;
return result;
}
private static final int IS_INITIAL_PARAMETER_FLAG = 1;
private static final int COULD_BE_ZERO_FLAG = 2;
private static final int IS_NULL_FLAG = 4;
public static final Object UNKNOWN = null;
private @SpecialKind
int specialKind = NOT_SPECIAL;
private String signature;
private Object constValue = UNKNOWN;
private @CheckForNull
ClassMember source;
private int pc = -1;
private int flags;
private int registerNumber = -1;
private Object userValue = null;
private HttpParameterInjection injection = null;
private int fieldLoadedFromRegister = -1;
public void makeCrossMethod() {
pc = -1;
registerNumber = -1;
fieldLoadedFromRegister = -1;
}
public int getSize() {
if (signature.equals("J") || signature.equals("D"))
return 2;
return 1;
}
public int getPC() {
return pc;
}
public void setPC(int pc) {
this.pc = pc;
}
public boolean isWide() {
return getSize() == 2;
}
@Override
public int hashCode() {
int r = 42 + specialKind;
if (signature != null)
r += signature.hashCode();
r *= 31;
if (constValue != null)
r += constValue.hashCode();
r *= 31;
if (source != null)
r += source.hashCode();
r *= 31;
r += flags;
r *= 31;
r += registerNumber;
return r;
}
public boolean usesTwoSlots() {
return getSize() == 2;
}
@Override
public boolean equals(Object o) {
if (!(o instanceof Item))
return false;
Item that = (Item) o;
return Util.nullSafeEquals(this.signature, that.signature) && Util.nullSafeEquals(this.constValue, that.constValue)
&& Util.nullSafeEquals(this.source, that.source) && Util.nullSafeEquals(this.userValue, that.userValue)
&& Util.nullSafeEquals(this.injection, that.injection) && this.specialKind == that.specialKind
&& this.registerNumber == that.registerNumber && this.flags == that.flags
&& this.fieldLoadedFromRegister == that.fieldLoadedFromRegister;
}
@Override
public String toString() {
StringBuilder buf = new StringBuilder("< ");
buf.append(signature);
switch (specialKind) {
case SIGNED_BYTE:
buf.append(", signed_byte");
break;
case RANDOM_INT:
buf.append(", random_int");
break;
case LOW_8_BITS_CLEAR:
buf.append(", low8clear");
break;
case HASHCODE_INT:
buf.append(", hashcode_int");
break;
case INTEGER_SUM:
buf.append(", int_sum");
break;
case AVERAGE_COMPUTED_USING_DIVISION:
buf.append(", averageComputingUsingDivision");
break;
case FLOAT_MATH:
buf.append(", floatMath");
break;
case NASTY_FLOAT_MATH:
buf.append(", nastyFloatMath");
break;
case HASHCODE_INT_REMAINDER:
buf.append(", hashcode_int_rem");
break;
case RANDOM_INT_REMAINDER:
buf.append(", random_int_rem");
break;
case MATH_ABS_OF_RANDOM:
buf.append(", abs_of_random");
break;
case MATH_ABS_OF_HASHCODE:
buf.append(", abs_of_hashcode");
break;
case FILE_SEPARATOR_STRING:
buf.append(", file_separator_string");
break;
case MATH_ABS:
buf.append(", Math.abs");
break;
case NON_NEGATIVE:
buf.append(", non_negative");
break;
case FILE_OPENED_IN_APPEND_MODE:
buf.append(", file opened in append mode");
break;
case SERVLET_REQUEST_TAINTED:
buf.append(", servlet request tainted");
break;
case NEWLY_ALLOCATED:
buf.append(", new");
break;
case ZERO_MEANS_NULL:
buf.append(", zero means null");
break;
case NONZERO_MEANS_NULL:
buf.append(", nonzero means null");
break;
case SERVLET_OUTPUT:
buf.append(", servlet_output");
break;
case TYPE_ONLY:
buf.append(", type_only");
break;
case NOT_SPECIAL:
break;
default:
buf.append(", #" + specialKind);
buf.append("(" + specialKindNames.get(specialKind) + ")");
break;
}
if (constValue != UNKNOWN) {
if (constValue instanceof String) {
buf.append(", \"");
buf.append(constValue);
buf.append("\"");
} else {
buf.append(", ");
buf.append(constValue);
}
}
if (source instanceof XField) {
buf.append(", ");
if (fieldLoadedFromRegister != -1 && fieldLoadedFromRegister != Integer.MAX_VALUE)
buf.append(fieldLoadedFromRegister).append(':');
buf.append(source);
}
if (source instanceof XMethod) {
buf.append(", return value from ");
buf.append(source);
}
if (isInitialParameter()) {
buf.append(", IP");
}
if (isNull()) {
buf.append(", isNull");
}
if (registerNumber != -1) {
buf.append(", r");
buf.append(registerNumber);
}
if (isCouldBeZero() && !isZero())
buf.append(", cbz");
if (userValue != null) {
buf.append(", uv: ");
buf.append(userValue.toString());
}
buf.append(" >");
return buf.toString();
}
public static Item merge(Item i1, Item i2) {
if (i1 == null)
return i2;
if (i2 == null)
return i1;
if (i1.equals(i2))
return i1;
Item m = new Item();
if (i1.getSpecialKind() == TYPE_ONLY && i2.getSpecialKind() != TYPE_ONLY)
return i2;
else if (i2.getSpecialKind() == TYPE_ONLY && i1.getSpecialKind() != TYPE_ONLY)
return i1;
m.flags = i1.flags & i2.flags;
m.setCouldBeZero(i1.isCouldBeZero() || i2.isCouldBeZero());
if (i1.pc == i2.pc)
m.pc = i1.pc;
if (Util.nullSafeEquals(i1.signature, i2.signature))
m.signature = i1.signature;
else if (i1.isNull())
m.signature = i2.signature;
else if (i2.isNull())
m.signature = i1.signature;
if (Util.nullSafeEquals(i1.constValue, i2.constValue))
m.constValue = i1.constValue;
if (Util.nullSafeEquals(i1.source, i2.source)) {
m.source = i1.source;
} else if ("".equals(i1.constValue))
m.source = i2.source;
else if ("".equals(i2.constValue))
m.source = i1.source;
if (Util.nullSafeEquals(i1.userValue, i2.userValue))
m.userValue = i1.userValue;
if (i1.registerNumber == i2.registerNumber)
m.registerNumber = i1.registerNumber;
if (i1.fieldLoadedFromRegister == i2.fieldLoadedFromRegister)
m.fieldLoadedFromRegister = i1.fieldLoadedFromRegister;
if (i1.specialKind == SERVLET_REQUEST_TAINTED) {
m.specialKind = SERVLET_REQUEST_TAINTED;
m.injection = i1.injection;
} else if (i2.specialKind == SERVLET_REQUEST_TAINTED) {
m.specialKind = SERVLET_REQUEST_TAINTED;
m.injection = i2.injection;
} else if (i1.specialKind == i2.specialKind)
m.specialKind = i1.specialKind;
else if (i1.specialKind == NASTY_FLOAT_MATH || i2.specialKind == NASTY_FLOAT_MATH)
m.specialKind = NASTY_FLOAT_MATH;
else if (i1.specialKind == FLOAT_MATH || i2.specialKind == FLOAT_MATH)
m.specialKind = FLOAT_MATH;
if (DEBUG)
System.out.println("Merge " + i1 + " and " + i2 + " gives " + m);
return m;
}
public Item(String signature, int constValue) {
this(signature, Integer.valueOf(constValue));
}
public static Item initialArgument(String signature, int reg) {
Item it = new Item(signature);
it.setInitialParameter(true);
it.registerNumber = reg;
return it;
}
public Item(String signature) {
this(signature, UNKNOWN);
}
public static Item typeOnly(String signature) {
Item it = new Item(signature, UNKNOWN);
it.setSpecialKind(TYPE_ONLY);
return it;
}
public Item(Item it) {
this.signature = it.signature;
this.constValue = it.constValue;
this.source = it.source;
this.fieldLoadedFromRegister = it.fieldLoadedFromRegister;
this.registerNumber = it.registerNumber;
this.userValue = it.userValue;
this.injection = it.injection;
this.flags = it.flags;
this.specialKind = it.specialKind;
this.pc = it.pc;
}
public Item(Item it, String signature) {
this(it);
this.signature = DescriptorFactory.canonicalizeString(signature);
if (constValue instanceof Number) {
Number constantNumericValue = (Number) constValue;
if (signature.equals("B"))
this.constValue = constantNumericValue.byteValue();
else if (signature.equals("S"))
this.constValue = constantNumericValue.shortValue();
else if (signature.equals("C"))
this.constValue = (char) constantNumericValue.intValue();
else if (signature.equals("I"))
this.constValue = constantNumericValue.intValue();
else if (signature.equals("D"))
this.constValue = constantNumericValue.doubleValue();
else if (signature.equals("F"))
this.constValue = constantNumericValue.floatValue();
}
char s = signature.charAt(0);
if (s != 'L' && s != '[')
this.source = null;
setSpecialKindFromSignature();
}
public Item(Item it, int reg) {
this(it);
this.registerNumber = reg;
}
public Item(String signature, FieldAnnotation f) {
this.signature = DescriptorFactory.canonicalizeString(signature);
setSpecialKindFromSignature();
if (f != null)
source = XFactory.createXField(f);
fieldLoadedFromRegister = -1;
}
public Item(String signature, FieldAnnotation f, int fieldLoadedFromRegister) {
this.signature = DescriptorFactory.canonicalizeString(signature);
if (f != null)
source = XFactory.createXField(f);
this.fieldLoadedFromRegister = fieldLoadedFromRegister;
}
/**
* If this value was loaded from an instance field,
* give the register number containing the object that the field was loaded from.
* If Integer.MAX value, the value was loaded from a static field
* If -1, we don't know or don't have the register containing the object that
* the field was loaded from.
* @return
*
*/
public int getFieldLoadedFromRegister() {
return fieldLoadedFromRegister;
}
public void setLoadedFromField(XField f, int fieldLoadedFromRegister) {
source = f;
this.fieldLoadedFromRegister = fieldLoadedFromRegister;
this.registerNumber = -1;
}
public @CheckForNull
String getHttpParameterName() {
if (!isServletParameterTainted())
throw new IllegalStateException();
if (injection == null)
return null;
return injection.parameterName;
}
public int getInjectionPC() {
if (!isServletParameterTainted())
throw new IllegalStateException();
if (injection == null)
return -1;
return injection.pc;
}
public Item(String signature, Object constantValue) {
this.signature = DescriptorFactory.canonicalizeString(signature);
setSpecialKindFromSignature();
constValue = constantValue;
if (constantValue instanceof Integer) {
int value = ((Integer) constantValue).intValue();
if (value != 0 && (value & 0xff) == 0)
specialKind = LOW_8_BITS_CLEAR;
if (value == 0)
setCouldBeZero(true);
} else if (constantValue instanceof Long) {
long value = ((Long) constantValue).longValue();
if (value != 0 && (value & 0xff) == 0)
specialKind = LOW_8_BITS_CLEAR;
if (value == 0)
setCouldBeZero(true);
}
}
private void setSpecialKindFromSignature() {
if (false && specialKind != NOT_SPECIAL)
return;
if (signature.equals("B"))
specialKind = SIGNED_BYTE;
else if (signature.equals("C"))
specialKind = NON_NEGATIVE;
}
public void setCouldBeNegative() {
if (specialKind == NON_NEGATIVE)
specialKind = NOT_SPECIAL;
}
public Item() {
signature = "Ljava/lang/Object;";
constValue = null;
setNull(true);
}
public static Item nullItem(String signature) {
Item item = new Item(signature);
item.constValue = null;
item.setNull(true);
return item;
}
/** Returns null for primitive and arrays */
public @CheckForNull
JavaClass getJavaClass() throws ClassNotFoundException {
String baseSig;
if (isPrimitive() || isArray())
return null;
baseSig = signature;
if (baseSig.length() == 0)
return null;
baseSig = baseSig.substring(1, baseSig.length() - 1);
baseSig = baseSig.replace('/', '.');
return Repository.lookupClass(baseSig);
}
public boolean isArray() {
return signature.startsWith("[");
}
@Deprecated
public String getElementSignature() {
if (!isArray())
return signature;
else {
int pos = 0;
int len = signature.length();
while (pos < len) {
if (signature.charAt(pos) != '[')
break;
pos++;
}
return signature.substring(pos);
}
}
public boolean isNonNegative() {
if (specialKind == NON_NEGATIVE)
return true;
if (constValue instanceof Number) {
double value = ((Number) constValue).doubleValue();
return value >= 0;
}
return false;
}
public boolean isPrimitive() {
return !signature.startsWith("L") && !signature.startsWith("[");
}
public int getRegisterNumber() {
return registerNumber;
}
public String getSignature() {
return signature;
}
/**
* Returns a constant value for this Item, if known. NOTE: if the value
* is a constant Class object, the constant value returned is the name
* of the class.
*/
public Object getConstant() {
return constValue;
}
/** Use getXField instead */
@Deprecated
public FieldAnnotation getFieldAnnotation() {
return FieldAnnotation.fromXField(getXField());
}
public XField getXField() {
if (source instanceof XField)
return (XField) source;
return null;
}
/**
* @param specialKind
* The specialKind to set.
*/
public void setSpecialKind(@SpecialKind int specialKind) {
this.specialKind = specialKind;
}
public Item cloneAndSetSpecialKind(@SpecialKind int specialKind) {
Item that = new Item(this);
that.specialKind = specialKind;
return that;
}
/**
* @return Returns the specialKind.
*/
public @SpecialKind
int getSpecialKind() {
return specialKind;
}
/**
* @return Returns the specialKind.
*/
public boolean isBooleanNullnessValue() {
return specialKind == ZERO_MEANS_NULL || specialKind == NONZERO_MEANS_NULL;
}
/**
* attaches a detector specified value to this item
*
* @param value
* the custom value to set
*/
public void setUserValue(Object value) {
userValue = value;
}
/**
*
* @return if this value is the return value of a method, give the
* method invoked
*/
public @CheckForNull
XMethod getReturnValueOf() {
if (source instanceof XMethod)
return (XMethod) source;
return null;
}
public boolean couldBeZero() {
return isCouldBeZero();
}
public boolean mustBeZero() {
Object value = getConstant();
return value instanceof Number && ((Number) value).intValue() == 0;
}
/**
* gets the detector specified value for this item
*
* @return the custom value
*/
public Object getUserValue() {
return userValue;
}
public boolean isServletParameterTainted() {
return getSpecialKind() == Item.SERVLET_REQUEST_TAINTED;
}
public void setServletParameterTainted() {
setSpecialKind(Item.SERVLET_REQUEST_TAINTED);
}
public void setIsServletWriter() {
setSpecialKind(Item.SERVLET_OUTPUT);
}
public boolean isServletWriter() {
if (getSpecialKind() == Item.SERVLET_OUTPUT)
return true;
if (getSignature().equals("Ljavax/servlet/ServletOutputStream;"))
return true;
XMethod writingToSource = getReturnValueOf();
return writingToSource != null && writingToSource.getClassName().equals("javax.servlet.http.HttpServletResponse")
&& (writingToSource.getName().equals("getWriter") || writingToSource.getName().equals("getOutputStream"));
}
public boolean valueCouldBeNegative() {
return !isNonNegative()
&& (getSpecialKind() == Item.RANDOM_INT || getSpecialKind() == Item.SIGNED_BYTE
|| getSpecialKind() == Item.HASHCODE_INT || getSpecialKind() == Item.RANDOM_INT_REMAINDER
|| getSpecialKind() == Item.HASHCODE_INT_REMAINDER || getSpecialKind() == Item.MATH_ABS_OF_RANDOM || getSpecialKind() == Item.MATH_ABS_OF_HASHCODE);
}
public @SpecialKind int getSpecialKindForAbs() {
switch (getSpecialKind()) {
case Item.HASHCODE_INT:
return Item.MATH_ABS_OF_HASHCODE;
case Item.RANDOM_INT:
return Item.MATH_ABS_OF_RANDOM;
default:
return Item.MATH_ABS;
}
}
public @SpecialKind int getSpecialKindForRemainder() {
switch (getSpecialKind()) {
case Item.HASHCODE_INT:
return Item.HASHCODE_INT_REMAINDER;
case Item.RANDOM_INT:
return Item.RANDOM_INT_REMAINDER;
default:
return Item.NOT_SPECIAL;
}
}
/** Value could be Integer.MIN_VALUE */
public boolean checkForIntegerMinValue() {
return !isNonNegative() && (getSpecialKind() == Item.RANDOM_INT || getSpecialKind() == Item.HASHCODE_INT);
}
/** The result of applying Math.abs to a checkForIntegerMinValue() value */
public boolean mightRarelyBeNegative() {
return !isNonNegative()
&& (getSpecialKind() == Item.MATH_ABS_OF_RANDOM || getSpecialKind() == Item.MATH_ABS_OF_HASHCODE);
}
/**
* @param isInitialParameter
* The isInitialParameter to set.
*/
private void setInitialParameter(boolean isInitialParameter) {
setFlag(isInitialParameter, IS_INITIAL_PARAMETER_FLAG);
}
/**
* @return Returns the isInitialParameter.
*/
public boolean isInitialParameter() {
return (flags & IS_INITIAL_PARAMETER_FLAG) != 0;
}
/**
* @param couldBeZero
* The couldBeZero to set.
*/
private void setCouldBeZero(boolean couldBeZero) {
setFlag(couldBeZero, COULD_BE_ZERO_FLAG);
}
/**
* @return Returns the couldBeZero.
*/
private boolean isCouldBeZero() {
return (flags & COULD_BE_ZERO_FLAG) != 0
|| isZero();
}
/**
* @return
*/
private boolean isZero() {
return constValue != null && constValue.equals(0);
}
/**
* @param isNull
* The isNull to set.
*/
private void setNull(boolean isNull) {
setFlag(isNull, IS_NULL_FLAG);
}
private void setFlag(boolean value, int flagBit) {
if (value)
flags |= flagBit;
else
flags &= ~flagBit;
}
/**
* @return Returns the isNull.
*/
public boolean isNull() {
return (flags & IS_NULL_FLAG) != 0;
}
/**
*
*/
public void clearNewlyAllocated() {
if (specialKind == NEWLY_ALLOCATED) {
if (signature.startsWith("Ljava/lang/StringB"))
constValue = null;
specialKind = NOT_SPECIAL;
}
}
public boolean isNewlyAllocated() {
return specialKind == NEWLY_ALLOCATED;
}
/**
* @param i
* @return
*/
public boolean hasConstantValue(int value) {
if (constValue instanceof Number)
return ((Number) constValue).intValue() == value;
return false;
}
public boolean hasConstantValue(long value) {
if (constValue instanceof Number)
return ((Number) constValue).longValue() == value;
return false;
}
}
@Override
public String toString() {
if (isTop())
return "TOP";
return stack.toString() + "::" + lvValues.toString();
}
public OpcodeStack() {
stack = new ArrayList<Item>();
lvValues = new ArrayList<Item>();
lastUpdate = new ArrayList<Integer>();
}
public boolean hasIncomingBranches(int pc) {
return jumpEntryLocations.get(pc) && jumpEntries.get(pc) != null;
}
boolean needToMerge = true;
private boolean reachOnlyByBranch = false;
public static String getExceptionSig(DismantleBytecode dbc, CodeException e) {
if (e.getCatchType() == 0)
return "Ljava/lang/Throwable;";
Constant c = dbc.getConstantPool().getConstant(e.getCatchType());
if (c instanceof ConstantClass)
return "L" + ((ConstantClass) c).getBytes(dbc.getConstantPool()) + ";";
return "Ljava/lang/Throwable;";
}
public void mergeJumps(DismantleBytecode dbc) {
if (!needToMerge)
return;
needToMerge = false;
if (dbc.getPC() == zeroOneComing) {
pop();
top = false;
OpcodeStack.Item item = new Item("I");
if (oneMeansNull)
item.setSpecialKind(Item.NONZERO_MEANS_NULL);
else
item.setSpecialKind(Item.ZERO_MEANS_NULL);
item.setPC(dbc.getPC() - 8);
item.setCouldBeZero(true);
push(item);
zeroOneComing = -1;
if (DEBUG)
System.out.println("Updated to " + this);
return;
}
boolean stackUpdated = false;
if (!isTop() && (convertJumpToOneZeroState == 3 || convertJumpToZeroOneState == 3)) {
pop();
Item topItem = new Item("I");
topItem.setCouldBeZero(true);
push(topItem);
convertJumpToOneZeroState = convertJumpToZeroOneState = 0;
stackUpdated = true;
}
List<Item> jumpEntry = null;
if (jumpEntryLocations.get(dbc.getPC()))
jumpEntry = jumpEntries.get(Integer.valueOf(dbc.getPC()));
boolean wasReachOnlyByBranch = isReachOnlyByBranch();
if (jumpEntry != null) {
setReachOnlyByBranch(false);
List<Item> jumpStackEntry = jumpStackEntries.get(Integer.valueOf(dbc.getPC()));
if (DEBUG2) {
if (wasReachOnlyByBranch) {
System.out.println("Reached by branch at " + dbc.getPC() + " with " + jumpEntry);
if (jumpStackEntry != null)
System.out.println(" and stack " + jumpStackEntry);
} else if (!jumpEntry.equals(lvValues)
|| jumpStackEntry != null && !jumpStackEntry.equals(stack)) {
System.out.println("Merging at " + dbc.getPC() + " with " + jumpEntry);
if (jumpStackEntry != null)
System.out.println(" and stack " + jumpStackEntry);
}
}
if (isTop()) {
lvValues = new ArrayList<Item>(jumpEntry);
if (jumpStackEntry != null)
stack = new ArrayList<Item>(jumpStackEntry);
else
stack.clear();
setTop(false);
return;
}
if (isReachOnlyByBranch()) {
setTop(false);
lvValues = new ArrayList<Item>(jumpEntry);
if (!stackUpdated) {
if (jumpStackEntry != null)
stack = new ArrayList<Item>(jumpStackEntry);
else
stack.clear();
}
} else {
setTop(false);
mergeLists(lvValues, jumpEntry, false);
if (!stackUpdated && jumpStackEntry != null)
mergeLists(stack, jumpStackEntry, false);
}
if (DEBUG)
System.out.println(" merged lvValues " + lvValues);
} else if (isReachOnlyByBranch() && !stackUpdated) {
stack.clear();
for (CodeException e : dbc.getCode().getExceptionTable()) {
if (e.getHandlerPC() == dbc.getPC()) {
push(new Item(getExceptionSig(dbc, e)));
setReachOnlyByBranch(false);
setTop(false);
return;
}
}
setTop(true);
}
}
int convertJumpToOneZeroState = 0;
int convertJumpToZeroOneState = 0;
int registerTestedFoundToBeNonnegative = -1;
private void setLastUpdate(int reg, int pc) {
while (lastUpdate.size() <= reg)
lastUpdate.add(Integer.valueOf(0));
lastUpdate.set(reg, Integer.valueOf(pc));
}
public int getLastUpdate(int reg) {
if (lastUpdate.size() <= reg)
return 0;
return lastUpdate.get(reg).intValue();
}
public int getNumLastUpdates() {
return lastUpdate.size();
}
int zeroOneComing = -1;
boolean oneMeansNull;
public void sawOpcode(DismantleBytecode dbc, int seen) {
int register;
String signature;
Item it, it2;
Constant cons;
// System.out.printf("%3d %12s%s%n", dbc.getPC(), OPCODE_NAMES[seen],
// this);
if (dbc.isRegisterStore())
setLastUpdate(dbc.getRegisterOperand(), dbc.getPC());
precomputation(dbc);
needToMerge = true;
try {
if (isTop()) {
encountedTop = true;
return;
}
if (seen == GOTO) {
int nextPC = dbc.getPC() + 3;
if (nextPC <= dbc.getMaxPC()) {
int prevOpcode1 = dbc.getPrevOpcode(1);
int prevOpcode2 = dbc.getPrevOpcode(2);
try {
int nextOpcode = dbc.getCodeByte(dbc.getPC() + 3);
if ((prevOpcode1 == ICONST_0 || prevOpcode1 == ICONST_1)
&& (prevOpcode2 == IFNULL || prevOpcode2 == IFNONNULL)
&& (nextOpcode == ICONST_0 || nextOpcode == ICONST_1) && prevOpcode1 != nextOpcode) {
oneMeansNull = prevOpcode1 == ICONST_0;
if (prevOpcode2 != IFNULL)
oneMeansNull = !oneMeansNull;
zeroOneComing = nextPC + 1;
convertJumpToOneZeroState = convertJumpToZeroOneState = 0;
}
} catch (ArrayIndexOutOfBoundsException e) {
throw e; // throw new
// ArrayIndexOutOfBoundsException(nextPC + " "
// + dbc.getMaxPC());
}
}
}
switch (seen) {
case ICONST_1:
convertJumpToOneZeroState = 1;
break;
case GOTO:
if (convertJumpToOneZeroState == 1 && dbc.getBranchOffset() == 4)
convertJumpToOneZeroState = 2;
else
convertJumpToOneZeroState = 0;
break;
case ICONST_0:
if (convertJumpToOneZeroState == 2)
convertJumpToOneZeroState = 3;
else
convertJumpToOneZeroState = 0;
break;
default:
convertJumpToOneZeroState = 0;
}
switch (seen) {
case ICONST_0:
convertJumpToZeroOneState = 1;
break;
case GOTO:
if (convertJumpToZeroOneState == 1 && dbc.getBranchOffset() == 4)
convertJumpToZeroOneState = 2;
else
convertJumpToZeroOneState = 0;
break;
case ICONST_1:
if (convertJumpToZeroOneState == 2)
convertJumpToZeroOneState = 3;
else
convertJumpToZeroOneState = 0;
break;
default:
convertJumpToZeroOneState = 0;
}
switch (seen) {
case ALOAD:
pushByLocalObjectLoad(dbc, dbc.getRegisterOperand());
break;
case ALOAD_0:
case ALOAD_1:
case ALOAD_2:
case ALOAD_3:
pushByLocalObjectLoad(dbc, seen - ALOAD_0);
break;
case DLOAD:
pushByLocalLoad("D", dbc.getRegisterOperand());
break;
case DLOAD_0:
case DLOAD_1:
case DLOAD_2:
case DLOAD_3:
pushByLocalLoad("D", seen - DLOAD_0);
break;
case FLOAD:
pushByLocalLoad("F", dbc.getRegisterOperand());
break;
case FLOAD_0:
case FLOAD_1:
case FLOAD_2:
case FLOAD_3:
pushByLocalLoad("F", seen - FLOAD_0);
break;
case ILOAD:
pushByLocalLoad("I", dbc.getRegisterOperand());
break;
case ILOAD_0:
case ILOAD_1:
case ILOAD_2:
case ILOAD_3:
pushByLocalLoad("I", seen - ILOAD_0);
break;
case LLOAD:
pushByLocalLoad("J", dbc.getRegisterOperand());
break;
case LLOAD_0:
case LLOAD_1:
case LLOAD_2:
case LLOAD_3:
pushByLocalLoad("J", seen - LLOAD_0);
break;
case GETSTATIC: {
FieldSummary fieldSummary = AnalysisContext.currentAnalysisContext().getFieldSummary();
XField fieldOperand = dbc.getXFieldOperand();
if (fieldOperand != null && fieldSummary.isComplete() && !fieldOperand.isPublic()) {
OpcodeStack.Item item = fieldSummary.getSummary(fieldOperand);
if (item != null) {
Item itm = new Item(item);
itm.setLoadedFromField(fieldOperand, Integer.MAX_VALUE);
itm.setPC(dbc.getPC());
push(itm);
break;
}
}
FieldAnnotation field = FieldAnnotation.fromReferencedField(dbc);
Item i = new Item(dbc.getSigConstantOperand(), field, Integer.MAX_VALUE);
if (field.getFieldName().equals("separator") && field.getClassName().equals("java.io.File")) {
i.setSpecialKind(Item.FILE_SEPARATOR_STRING);
}
i.setPC(dbc.getPC());
push(i);
break;
}
case LDC:
case LDC_W:
case LDC2_W:
cons = dbc.getConstantRefOperand();
pushByConstant(dbc, cons);
break;
case INSTANCEOF:
pop();
push(new Item("I"));
break;
case IFNONNULL:
case IFNULL:
// {
// Item topItem = pop();
// if (seen == IFNONNULL && topItem.isNull())
// break;
// seenTransferOfControl = true;
// addJumpValue(dbc.getPC(), dbc.getBranchTarget());
//
// break;
// }
case IFEQ:
case IFNE:
case IFLT:
case IFLE:
case IFGT:
case IFGE:
seenTransferOfControl = true;
{
Item topItem = pop();
// System.out.printf("%4d %10s %s%n",
// dbc.getPC(),OPCODE_NAMES[seen], topItem);
if (seen == IFLT || seen == IFLE) {
registerTestedFoundToBeNonnegative = topItem.registerNumber;
}
// if we see a test comparing a special negative value with
// 0,
// reset all other such values on the opcode stack
if (topItem.valueCouldBeNegative() && (seen == IFLT || seen == IFLE || seen == IFGT || seen == IFGE)) {
int specialKind = topItem.getSpecialKind();
for (Item item : stack)
if (item != null && item.getSpecialKind() == specialKind)
item.setSpecialKind(Item.NOT_SPECIAL);
for (Item item : lvValues)
if (item != null && item.getSpecialKind() == specialKind)
item.setSpecialKind(Item.NOT_SPECIAL);
}
}
addJumpValue(dbc.getPC(), dbc.getBranchTarget());
break;
case LOOKUPSWITCH:
case TABLESWITCH:
seenTransferOfControl = true;
setReachOnlyByBranch(true);
pop();
addJumpValue(dbc.getPC(), dbc.getBranchTarget());
int pc = dbc.getBranchTarget() - dbc.getBranchOffset();
for (int offset : dbc.getSwitchOffsets())
addJumpValue(dbc.getPC(), offset + pc);
break;
case ARETURN:
case DRETURN:
case FRETURN:
case IRETURN:
case LRETURN:
seenTransferOfControl = true;
setReachOnlyByBranch(true);
pop();
break;
case MONITORENTER:
case MONITOREXIT:
case POP:
pop();
break;
case PUTSTATIC:
pop();
eraseKnowledgeOf(dbc.getXFieldOperand());
break;
case PUTFIELD:
pop(2);
eraseKnowledgeOf(dbc.getXFieldOperand());
break;
case IF_ACMPEQ:
case IF_ACMPNE:
case IF_ICMPEQ:
case IF_ICMPNE:
case IF_ICMPLT:
case IF_ICMPLE:
case IF_ICMPGT:
case IF_ICMPGE:
{
seenTransferOfControl = true;
Item right = pop();
Item left = pop();
Object lConstant = left.getConstant();
Object rConstant = right.getConstant();
boolean takeJump = false;
boolean handled = false;
if (seen == IF_ACMPNE || seen == IF_ACMPEQ) {
if (lConstant != null && rConstant != null && !lConstant.equals(rConstant) || lConstant != null
&& right.isNull() || rConstant != null && left.isNull()) {
handled = true;
takeJump = seen == IF_ACMPNE;
}
} else if (lConstant instanceof Integer && rConstant instanceof Integer) {
int lC = ((Integer) lConstant).intValue();
int rC = ((Integer) rConstant).intValue();
switch (seen) {
case IF_ICMPEQ:
takeJump = lC == rC;
handled = true;
break;
case IF_ICMPNE:
takeJump = lC != rC;
handled = true;
break;
case IF_ICMPGE:
takeJump = lC >= rC;
handled = true;
break;
case IF_ICMPGT:
takeJump = lC > rC;
handled = true;
break;
case IF_ICMPLE:
takeJump = lC <= rC;
handled = true;
break;
case IF_ICMPLT:
takeJump = lC < rC;
handled = true;
break;
default:
assert false;
}
}
if (handled) {
if (takeJump) {
int branchTarget = dbc.getBranchTarget();
addJumpValue(dbc.getPC(), branchTarget);
setTop(true);
break;
} else {
break;
}
}
if (right.hasConstantValue(Integer.MIN_VALUE) && left.mightRarelyBeNegative()
|| left.hasConstantValue(Integer.MIN_VALUE) && right.mightRarelyBeNegative()) {
for (Item i : stack)
if (i != null && i.mightRarelyBeNegative())
i.setSpecialKind(Item.NOT_SPECIAL);
for (Item i : lvValues)
if (i != null && i.mightRarelyBeNegative())
i.setSpecialKind(Item.NOT_SPECIAL);
}
int branchTarget = dbc.getBranchTarget();
addJumpValue(dbc.getPC(), branchTarget);
break;
}
case POP2:
it = pop();
if (it.getSize() == 1)
pop();
break;
case IALOAD:
case SALOAD:
pop(2);
push(new Item("I"));
break;
case DUP:
handleDup();
break;
case DUP2:
handleDup2();
break;
case DUP_X1:
handleDupX1();
break;
case DUP_X2:
handleDupX2();
break;
case DUP2_X1:
handleDup2X1();
break;
case DUP2_X2:
handleDup2X2();
break;
case IINC:
register = dbc.getRegisterOperand();
it = getLVValue(register);
it2 = new Item("I", dbc.getIntConstant());
pushByIntMath(dbc, IADD, it2, it);
pushByLocalStore(register);
break;
case ATHROW:
pop();
seenTransferOfControl = true;
setReachOnlyByBranch(true);
setTop(true);
break;
case CHECKCAST: {
String castTo = dbc.getClassConstantOperand();
if (castTo.charAt(0) != '[')
castTo = "L" + castTo + ";";
it = pop();
if (!it.signature.equals(castTo)) {
it = new Item(it, castTo);
}
push(it);
break;
}
case NOP:
break;
case RET:
case RETURN:
seenTransferOfControl = true;
setReachOnlyByBranch(true);
break;
case GOTO:
case GOTO_W:
seenTransferOfControl = true;
setReachOnlyByBranch(true);
addJumpValue(dbc.getPC(), dbc.getBranchTarget());
stack.clear();
setTop(true);
break;
case SWAP:
handleSwap();
break;
case ICONST_M1:
case ICONST_0:
case ICONST_1:
case ICONST_2:
case ICONST_3:
case ICONST_4:
case ICONST_5:
push(new Item("I", (seen - ICONST_0)));
break;
case LCONST_0:
case LCONST_1:
push(new Item("J", Long.valueOf(seen - LCONST_0)));
break;
case DCONST_0:
case DCONST_1:
push(new Item("D", Double.valueOf(seen - DCONST_0)));
break;
case FCONST_0:
case FCONST_1:
case FCONST_2:
push(new Item("F", Float.valueOf(seen - FCONST_0)));
break;
case ACONST_NULL:
push(new Item());
break;
case ASTORE:
case DSTORE:
case FSTORE:
case ISTORE:
case LSTORE:
pushByLocalStore(dbc.getRegisterOperand());
break;
case ASTORE_0:
case ASTORE_1:
case ASTORE_2:
case ASTORE_3:
pushByLocalStore(seen - ASTORE_0);
break;
case DSTORE_0:
case DSTORE_1:
case DSTORE_2:
case DSTORE_3:
pushByLocalStore(seen - DSTORE_0);
break;
case FSTORE_0:
case FSTORE_1:
case FSTORE_2:
case FSTORE_3:
pushByLocalStore(seen - FSTORE_0);
break;
case ISTORE_0:
case ISTORE_1:
case ISTORE_2:
case ISTORE_3:
pushByLocalStore(seen - ISTORE_0);
break;
case LSTORE_0:
case LSTORE_1:
case LSTORE_2:
case LSTORE_3:
pushByLocalStore(seen - LSTORE_0);
break;
case GETFIELD: {
FieldSummary fieldSummary = AnalysisContext.currentAnalysisContext().getFieldSummary();
XField fieldOperand = dbc.getXFieldOperand();
if (fieldOperand != null && fieldSummary.isComplete() && !fieldOperand.isPublic()) {
OpcodeStack.Item item = fieldSummary.getSummary(fieldOperand);
if (item != null) {
Item addr = pop();
Item itm = new Item(item);
itm.setLoadedFromField(fieldOperand, addr.getRegisterNumber());
itm.setPC(dbc.getPC());
push(itm);
break;
}
}
Item item = pop();
int reg = item.getRegisterNumber();
Item valueLoaded = new Item(dbc.getSigConstantOperand(), FieldAnnotation.fromReferencedField(dbc), reg);
valueLoaded.setPC(dbc.getPC());
push(valueLoaded);
}
break;
case ARRAYLENGTH: {
pop();
Item newItem = new Item("I");
newItem.setSpecialKind(Item.NON_NEGATIVE);
push(newItem);
}
break;
case BALOAD: {
pop(2);
Item newItem = new Item("I");
newItem.setSpecialKind(Item.SIGNED_BYTE);
push(newItem);
break;
}
case CALOAD:
pop(2);
push(new Item("I"));
break;
case DALOAD:
pop(2);
push(new Item("D"));
break;
case FALOAD:
pop(2);
push(new Item("F"));
break;
case LALOAD:
pop(2);
push(new Item("J"));
break;
case AASTORE:
case BASTORE:
case CASTORE:
case DASTORE:
case FASTORE:
case IASTORE:
case LASTORE:
case SASTORE:
pop(3);
break;
case BIPUSH:
case SIPUSH:
push(new Item("I", Integer.valueOf(dbc.getIntConstant())));
break;
case IADD:
case ISUB:
case IMUL:
case IDIV:
case IAND:
case IOR:
case IXOR:
case ISHL:
case ISHR:
case IREM:
case IUSHR:
it = pop();
it2 = pop();
pushByIntMath(dbc, seen, it2, it);
break;
case INEG:
it = pop();
if (it.getConstant() instanceof Integer) {
push(new Item("I", Integer.valueOf(-constantToInt(it))));
} else {
push(new Item("I"));
}
break;
case LNEG:
it = pop();
if (it.getConstant() instanceof Long) {
push(new Item("J", Long.valueOf(-constantToLong(it))));
} else {
push(new Item("J"));
}
break;
case FNEG:
it = pop();
if (it.getConstant() instanceof Float) {
push(new Item("F", Float.valueOf(-constantToFloat(it))));
} else {
push(new Item("F"));
}
break;
case DNEG:
it = pop();
if (it.getConstant() instanceof Double) {
push(new Item("D", Double.valueOf(-constantToDouble(it))));
} else {
push(new Item("D"));
}
break;
case LADD:
case LSUB:
case LMUL:
case LDIV:
case LAND:
case LOR:
case LXOR:
case LSHL:
case LSHR:
case LREM:
case LUSHR:
it = pop();
it2 = pop();
pushByLongMath(seen, it2, it);
break;
case LCMP:
handleLcmp();
break;
case FCMPG:
case FCMPL:
handleFcmp(seen);
break;
case DCMPG:
case DCMPL:
handleDcmp(seen);
break;
case FADD:
case FSUB:
case FMUL:
case FDIV:
case FREM:
it = pop();
it2 = pop();
pushByFloatMath(seen, it, it2);
break;
case DADD:
case DSUB:
case DMUL:
case DDIV:
case DREM:
it = pop();
it2 = pop();
pushByDoubleMath(seen, it, it2);
break;
case I2B: {
it = pop();
Item newValue = new Item(it, "B");
newValue.setCouldBeNegative();
push(newValue);
}
break;
case I2C: {
it = pop();
Item newValue = new Item(it, "C");
push(newValue);
}
break;
case I2L:
case D2L:
case F2L: {
it = pop();
Item newValue = new Item(it, "J");
int specialKind = it.getSpecialKind();
if (specialKind != Item.SIGNED_BYTE && seen == I2L)
newValue.setSpecialKind(Item.RESULT_OF_I2L);
push(newValue);
}
break;
case I2S:
{
Item item1 = pop();
Item newValue = new Item(item1, "S");
newValue.setCouldBeNegative();
push(newValue);
}
break;
case L2I:
case D2I:
case F2I:
it = pop();
int oldSpecialKind = it.getSpecialKind();
it = new Item(it, "I");
if (oldSpecialKind == Item.NOT_SPECIAL)
it.setSpecialKind(Item.RESULT_OF_L2I);
push(it);
break;
case L2F:
case D2F:
case I2F:
it = pop();
if (it.getConstant() != null) {
push(new Item("F", Float.valueOf(constantToFloat(it))));
} else {
push(new Item("F"));
}
break;
case F2D:
case I2D:
case L2D:
it = pop();
if (it.getConstant() != null) {
push(new Item("D", Double.valueOf(constantToDouble(it))));
} else {
push(new Item("D"));
}
break;
case NEW: {
Item item = new Item("L" + dbc.getClassConstantOperand() + ";", (Object) null);
item.setSpecialKind(Item.NEWLY_ALLOCATED);
push(item);
}
break;
case NEWARRAY:
pop();
signature = "[" + BasicType.getType((byte) dbc.getIntConstant()).getSignature();
pushBySignature(signature, dbc);
break;
// According to the VM Spec 4.4.1, anewarray and multianewarray
// can refer to normal class/interface types (encoded in
// "internal form"), or array classes (encoded as signatures
// beginning with "[").
case ANEWARRAY:
pop();
signature = dbc.getClassConstantOperand();
if (signature.charAt(0) == '[')
signature = "[" + signature;
else
signature = "[L" + signature + ";";
pushBySignature(signature, dbc);
break;
case MULTIANEWARRAY:
int dims = dbc.getIntConstant();
for (int i = 0; i < dims; i++)
pop();
signature = dbc.getClassConstantOperand();
pushBySignature(signature, dbc);
break;
case AALOAD: {
pop();
it = pop();
String arraySig = it.getSignature();
if (arraySig.charAt(0) == '[')
pushBySignature(arraySig.substring(1), dbc);
else
push(new Item());
}
break;
case JSR:
seenTransferOfControl = true;
setReachOnlyByBranch(false);
push(new Item("")); // push return address on stack
addJumpValue(dbc.getPC(), dbc.getBranchTarget());
pop();
if (dbc.getBranchOffset() < 0) {
// OK, backwards JSRs are weird; reset the stack.
int stackSize = stack.size();
stack.clear();
for (int i = 0; i < stackSize; i++)
stack.add(new Item());
}
setTop(false);
break;
case INVOKEINTERFACE:
case INVOKESPECIAL:
case INVOKESTATIC:
case INVOKEVIRTUAL:
processMethodCall(dbc, seen);
break;
default:
throw new UnsupportedOperationException("OpCode " + OPCODE_NAMES[seen] + " not supported ");
}
}
catch (RuntimeException e) {
// If an error occurs, we clear the stack and locals. one of two
// things will occur.
// Either the client will expect more stack items than really exist,
// and so they're condition check will fail,
// or the stack will resync with the code. But hopefully not false
// positives
String msg = "Error processing opcode " + OPCODE_NAMES[seen] + " @ " + dbc.getPC() + " in "
+ dbc.getFullyQualifiedMethodName();
AnalysisContext.logError(msg, e);
if (DEBUG)
e.printStackTrace();
clear();
} finally {
if (DEBUG) {
System.out.printf("%4d: %14s %s%n", dbc.getPC(), OPCODE_NAMES[seen] , this);
}
}
}
/**
* @param fieldOperand
*/
private void eraseKnowledgeOf(XField fieldOperand) {
if (fieldOperand == null) return;
for (Item item : stack)
if (item != null && fieldOperand.equals(item.getXField()))
item.setLoadedFromField(null, -1);
for (Item item : lvValues)
if (item != null && fieldOperand.equals(item.getXField()))
item.setLoadedFromField(null, -1);
}
public void precomputation(DismantleBytecode dbc) {
if (registerTestedFoundToBeNonnegative >= 0) {
for (int i = 0; i < stack.size(); i++) {
Item item = stack.get(i);
if (item != null && item.registerNumber == registerTestedFoundToBeNonnegative)
stack.set(i, item.cloneAndSetSpecialKind(Item.NON_NEGATIVE));
}
for (int i = 0; i < lvValues.size(); i++) {
Item item = lvValues.get(i);
if (item != null && item.registerNumber == registerTestedFoundToBeNonnegative)
lvValues.set(i, item.cloneAndSetSpecialKind(Item.NON_NEGATIVE));
}
}
registerTestedFoundToBeNonnegative = -1;
mergeJumps(dbc);
}
/**
* @param it
* @return
*/
private int constantToInt(Item it) {
Object constant = it.getConstant();
if (constant instanceof Number) {
return ((Number) constant).intValue();
}
if (constant instanceof Character) {
return ((Character) constant).charValue();
}
throw new IllegalArgumentException(String.valueOf(constant));
}
/**
* @param it
* @return
*/
private float constantToFloat(Item it) {
return ((Number) it.getConstant()).floatValue();
}
/**
* @param it
* @return
*/
private double constantToDouble(Item it) {
return ((Number) it.getConstant()).doubleValue();
}
/**
* @param it
* @return
*/
private long constantToLong(Item it) {
return ((Number) it.getConstant()).longValue();
}
/**
* handle dcmp
*
*/
private void handleDcmp(int opcode) {
Item it = pop();
Item it2 = pop();
if ((it.getConstant() != null) && it2.getConstant() != null) {
double d = constantToDouble(it);
double d2 = constantToDouble(it2);
if (Double.isNaN(d) || Double.isNaN(d2)) {
if (opcode == DCMPG)
push(new Item("I", Integer.valueOf(1)));
else
push(new Item("I", Integer.valueOf(-1)));
}
if (d2 < d)
push(new Item("I", Integer.valueOf(-1)));
else if (d2 > d)
push(new Item("I", Integer.valueOf(1)));
else
push(new Item("I", Integer.valueOf(0)));
} else {
push(new Item("I"));
}
}
/**
* handle fcmp
*
*/
private void handleFcmp(int opcode) {
Item it = pop();
Item it2 = pop();
if ((it.getConstant() != null) && it2.getConstant() != null) {
float f = constantToFloat(it);
float f2 = constantToFloat(it2);
if (Float.isNaN(f) || Float.isNaN(f2)) {
if (opcode == FCMPG)
push(new Item("I", Integer.valueOf(1)));
else
push(new Item("I", Integer.valueOf(-1)));
}
if (f2 < f)
push(new Item("I", Integer.valueOf(-1)));
else if (f2 > f)
push(new Item("I", Integer.valueOf(1)));
else
push(new Item("I", Integer.valueOf(0)));
} else {
push(new Item("I"));
}
}
/**
* handle lcmp
*/
private void handleLcmp() {
Item it = pop();
Item it2 = pop();
if ((it.getConstant() != null) && it2.getConstant() != null) {
long l = constantToLong(it);
long l2 = constantToLong(it2);
if (l2 < l)
push(new Item("I", Integer.valueOf(-1)));
else if (l2 > l)
push(new Item("I", Integer.valueOf(1)));
else
push(new Item("I", Integer.valueOf(0)));
} else {
push(new Item("I"));
}
}
/**
* handle swap
*/
private void handleSwap() {
Item i1 = pop();
Item i2 = pop();
push(i1);
push(i2);
}
/**
* handleDup
*/
private void handleDup() {
Item it;
it = pop();
push(it);
push(it);
}
/**
* handle dupX1
*/
private void handleDupX1() {
Item it;
Item it2;
it = pop();
it2 = pop();
push(it);
push(it2);
push(it);
}
/**
* handle dup2
*/
private void handleDup2() {
Item it, it2;
it = pop();
if (it.getSize() == 2) {
push(it);
push(it);
} else {
it2 = pop();
push(it2);
push(it);
push(it2);
push(it);
}
}
/**
* handle Dup2x1
*/
private void handleDup2X1() {
String signature;
Item it;
Item it2;
Item it3;
it = pop();
it2 = pop();
signature = it.getSignature();
if (signature.equals("J") || signature.equals("D")) {
push(it);
push(it2);
push(it);
} else {
it3 = pop();
push(it2);
push(it);
push(it3);
push(it2);
push(it);
}
}
private void handleDup2X2() {
Item it = pop();
Item it2 = pop();
if (it.isWide()) {
if (it2.isWide()) {
push(it);
push(it2);
push(it);
} else {
Item it3 = pop();
push(it);
push(it3);
push(it2);
push(it);
}
} else {
Item it3 = pop();
if (it3.isWide()) {
push(it2);
push(it);
push(it3);
push(it2);
push(it);
} else {
Item it4 = pop();
push(it2);
push(it);
push(it4);
push(it3);
push(it2);
push(it);
}
}
}
/**
* Handle DupX2
*/
private void handleDupX2() {
String signature;
Item it;
Item it2;
Item it3;
it = pop();
it2 = pop();
signature = it2.getSignature();
if (signature.equals("J") || signature.equals("D")) {
push(it);
push(it2);
push(it);
} else {
it3 = pop();
push(it);
push(it3);
push(it2);
push(it);
}
}
@edu.umd.cs.findbugs.internalAnnotations.StaticConstant
static final HashMap<String, String> boxedTypes = new HashMap<String, String>();
static private void addBoxedType(Class<?>... clss) {
for (Class<?> c : clss) {
Class<?> primitiveType;
try {
primitiveType = (Class<?>) c.getField("TYPE").get(null);
boxedTypes.put(ClassName.toSlashedClassName(c.getName()), primitiveType.getName());
} catch (Exception e) {
throw new AssertionError(e);
}
}
}
static {
addBoxedType(Integer.class, Long.class, Double.class, Short.class, Float.class, Boolean.class, Character.class,
Byte.class);
}
private void markConstantValueUnknown(Item item) {
item.constValue = null;
if (item.registerNumber >= 0) {
OpcodeStack.Item sbItem = getLVValue(item.registerNumber);
if (sbItem != null && sbItem.getSignature().equals(item.getSignature()))
sbItem.constValue = null;
}
}
private void processMethodCall(DismantleBytecode dbc, int seen) {
@SlashedClassName String clsName = dbc.getClassConstantOperand();
String methodName = dbc.getNameConstantOperand();
String signature = dbc.getSigConstantOperand();
String appenderValue = null;
boolean servletRequestParameterTainted = false;
boolean sawUnknownAppend = false;
Item sbItem = null;
Item topItem = null;
if (getStackDepth() > 0)
topItem = getStackItem(0);
int numberArguments = PreorderVisitor.getNumberArguments(signature);
if (boxedTypes.containsKey(clsName)
&& topItem != null
&& (methodName.equals("valueOf") && !signature.contains("String") || methodName.equals(boxedTypes.get(clsName)
+ "Value"))) {
// boxing/unboxing conversion
Item value = pop();
String newSignature = Type.getReturnType(signature).getSignature();
Item newValue = new Item(value, newSignature);
if (newValue.source == null)
newValue.source = XFactory.createReferencedXMethod(dbc);
if (newValue.specialKind == Item.NOT_SPECIAL) {
if (newSignature.equals("B") || newSignature.equals("Ljava/lang/Boolean;"))
newValue.specialKind = Item.SIGNED_BYTE;
else if (newSignature.equals("C") || newSignature.equals("Ljava/lang/Character;"))
newValue.specialKind = Item.NON_NEGATIVE;
}
push(newValue);
return;
}
int firstArgument = seen == INVOKESTATIC ? 0 : 1;
for (int i = firstArgument; i < firstArgument + numberArguments; i++) {
if (i >= getStackDepth())
break;
Item item = getStackItem(i);
String itemSignature = item.getSignature();
if (itemSignature.equals("Ljava/lang/StringBuilder;") || itemSignature.equals("Ljava/lang/StringBuffer;"))
markConstantValueUnknown(item);
}
boolean initializingServletWriter = false;
if (seen == INVOKESPECIAL && methodName.equals("<init>") && clsName.startsWith("java/io") && clsName.endsWith("Writer")
&& numberArguments > 0) {
Item firstArg = getStackItem(numberArguments-1);
if (firstArg.isServletWriter())
initializingServletWriter = true;
}
boolean topIsTainted = topItem != null && topItem.isServletParameterTainted();
HttpParameterInjection injection = null;
if (topIsTainted)
injection = topItem.injection;
// TODO: stack merging for trinaries kills the constant.. would be nice
// to maintain.
if ("java/lang/StringBuffer".equals(clsName) || "java/lang/StringBuilder".equals(clsName)) {
if ("<init>".equals(methodName)) {
if ("(Ljava/lang/String;)V".equals(signature)) {
Item i = getStackItem(0);
appenderValue = (String) i.getConstant();
if (i.isServletParameterTainted())
servletRequestParameterTainted = true;
} else if ("()V".equals(signature)) {
appenderValue = "";
}
} else if ("toString".equals(methodName) && getStackDepth() >= 1) {
Item i = getStackItem(0);
appenderValue = (String) i.getConstant();
if (i.isServletParameterTainted())
servletRequestParameterTainted = true;
} else if ("append".equals(methodName)) {
if (signature.indexOf("II)") == -1 && getStackDepth() >= 2) {
sbItem = getStackItem(1);
Item i = getStackItem(0);
if (i.isServletParameterTainted() || sbItem.isServletParameterTainted())
servletRequestParameterTainted = true;
Object sbVal = sbItem.getConstant();
Object sVal = i.getConstant();
if ((sbVal != null) && (sVal != null)) {
appenderValue = sbVal + sVal.toString();
} else
markConstantValueUnknown(sbItem);
} else if (signature.startsWith("([CII)")) {
sawUnknownAppend = true;
sbItem = getStackItem(3);
markConstantValueUnknown(sbItem);
} else {
sawUnknownAppend = true;
}
}
} else if (seen == INVOKESPECIAL && clsName.equals("java/io/FileOutputStream") && methodName.equals("<init>")
&& (signature.equals("(Ljava/io/File;Z)V") || signature.equals("(Ljava/lang/String;Z)V")) && stack.size() > 3) {
OpcodeStack.Item item = getStackItem(0);
Object value = item.getConstant();
if (value instanceof Integer && ((Integer) value).intValue() == 1) {
pop(3);
Item newTop = getStackItem(0);
if (newTop.signature.equals("Ljava/io/FileOutputStream;")) {
newTop.setSpecialKind(Item.FILE_OPENED_IN_APPEND_MODE);
newTop.source = XFactory.createReferencedXMethod(dbc);
newTop.setPC(dbc.getPC());
}
return;
}
} else if (seen == INVOKESPECIAL && clsName.equals("java/io/BufferedOutputStream") && methodName.equals("<init>")
&& signature.equals("(Ljava/io/OutputStream;)V")) {
if (getStackItem(0).getSpecialKind() == Item.FILE_OPENED_IN_APPEND_MODE
&& getStackItem(2).signature.equals("Ljava/io/BufferedOutputStream;")) {
pop(2);
Item newTop = getStackItem(0);
newTop.setSpecialKind(Item.FILE_OPENED_IN_APPEND_MODE);
newTop.source = XFactory.createReferencedXMethod(dbc);
newTop.setPC(dbc.getPC());
return;
}
} else if (seen == INVOKEINTERFACE && methodName.equals("getParameter")
&& clsName.equals("javax/servlet/http/HttpServletRequest") || clsName.equals("javax/servlet/http/ServletRequest")) {
Item requestParameter = pop();
pop();
Item result = new Item("Ljava/lang/String;");
result.setServletParameterTainted();
result.source = XFactory.createReferencedXMethod(dbc);
String parameterName = null;
if (requestParameter.getConstant() instanceof String)
parameterName = (String) requestParameter.getConstant();
result.injection = new HttpParameterInjection(parameterName, dbc.getPC());
result.setPC(dbc.getPC());
push(result);
return;
} else if (seen == INVOKEINTERFACE && methodName.equals("getQueryString")
&& clsName.equals("javax/servlet/http/HttpServletRequest") || clsName.equals("javax/servlet/http/ServletRequest")) {
pop();
Item result = new Item("Ljava/lang/String;");
result.setServletParameterTainted();
result.source = XFactory.createReferencedXMethod(dbc);
result.setPC(dbc.getPC());
push(result);
return;
} else if (seen == INVOKEINTERFACE && methodName.equals("getHeader")
&& clsName.equals("javax/servlet/http/HttpServletRequest") || clsName.equals("javax/servlet/http/ServletRequest")) {
/* Item requestParameter = */pop();
pop();
Item result = new Item("Ljava/lang/String;");
result.setServletParameterTainted();
result.source = XFactory.createReferencedXMethod(dbc);
result.setPC(dbc.getPC());
push(result);
return;
} else if (seen == INVOKESTATIC && methodName.equals("asList") && clsName.equals("java/util/Arrays")) {
/* Item requestParameter = */pop();
Item result = new Item(JAVA_UTIL_ARRAYS_ARRAY_LIST);
push(result);
return;
} else if (seen == INVOKESTATIC && signature.equals("(Ljava/util/List;)Ljava/util/List;")
&& clsName.equals("java/util/Collections")) {
Item requestParameter = pop();
if (requestParameter.getSignature().equals(JAVA_UTIL_ARRAYS_ARRAY_LIST)) {
Item result = new Item(JAVA_UTIL_ARRAYS_ARRAY_LIST);
push(result);
return;
}
push(requestParameter); // fall back to standard logic
}
pushByInvoke(dbc, seen != INVOKESTATIC);
if (initializingServletWriter)
this.getStackItem(0).setIsServletWriter();
if ((sawUnknownAppend || appenderValue != null || servletRequestParameterTainted) && getStackDepth() > 0) {
Item i = this.getStackItem(0);
i.constValue = appenderValue;
if (!sawUnknownAppend && servletRequestParameterTainted) {
i.injection = topItem.injection;
i.setServletParameterTainted();
}
if (sbItem != null) {
i.registerNumber = sbItem.registerNumber;
i.source = sbItem.source;
if (i.injection == null)
i.injection = sbItem.injection;
if (sbItem.registerNumber >= 0)
setLVValue(sbItem.registerNumber, i);
}
return;
}
if ((clsName.equals("java/util/Random") || clsName.equals("java/security/SecureRandom")) &&
(methodName.equals("nextInt") && signature.equals("()I")
|| methodName.equals("nextLong") && signature.equals("()J"))
) {
Item i = new Item(pop());
i.setSpecialKind(Item.RANDOM_INT);
push(i);
} else if (methodName.equals("size") && signature.equals("()I")
&& Subtypes2.instanceOf(ClassName.toDottedClassName(clsName), "java.util.Collection")) {
Item i = new Item(pop());
if (i.getSpecialKind() == Item.NOT_SPECIAL)
i.setSpecialKind(Item.NON_NEGATIVE);
push(i);
} else if (ClassName.isMathClass(clsName) && methodName.equals("abs")) {
Item i = new Item(pop());
if (i.getSpecialKind() == Item.HASHCODE_INT)
i.setSpecialKind(Item.MATH_ABS_OF_HASHCODE);
else if (i.getSpecialKind() == Item.RANDOM_INT)
i.setSpecialKind(Item.MATH_ABS_OF_RANDOM);
else
i.setSpecialKind(Item.MATH_ABS);
push(i);
} else if (seen == INVOKEVIRTUAL && methodName.equals("hashCode") && signature.equals("()I") || seen == INVOKESTATIC
&& clsName.equals("java/lang/System") && methodName.equals("identityHashCode")
&& signature.equals("(Ljava/lang/Object;)I")) {
Item i = new Item(pop());
i.setSpecialKind(Item.HASHCODE_INT);
push(i);
} else if (topIsTainted
&& (methodName.startsWith("encode") && clsName.equals("javax/servlet/http/HttpServletResponse") || methodName
.equals("trim") && clsName.equals("java/lang/String"))) {
Item i = new Item(pop());
i.setSpecialKind(Item.SERVLET_REQUEST_TAINTED);
i.injection = injection;
push(i);
}
if (!signature.endsWith(")V")) {
Item i = new Item(pop());
i.source = XFactory.createReferencedXMethod(dbc);
push(i);
}
}
boolean foobar = false;
private boolean mergeLists(List<Item> mergeInto, List<Item> mergeFrom, boolean errorIfSizesDoNotMatch) {
// merge stacks
int intoSize = mergeInto.size();
int fromSize = mergeFrom.size();
boolean changed = false;
if (errorIfSizesDoNotMatch && intoSize != fromSize) {
if (DEBUG2) {
System.out.println("Bad merging items");
System.out.println("current items: " + mergeInto);
System.out.println("jump items: " + mergeFrom);
}
} else {
if (DEBUG2) {
if (intoSize != fromSize) {
System.out.printf("Bad merging %d items from %d items%n", intoSize, fromSize);
System.out.println("current items: " + mergeInto);
System.out.println("jump items: " + mergeFrom);
}
}
List<Item> mergeIntoCopy = null;
if (DEBUG2)
mergeIntoCopy = new ArrayList<Item>(mergeInto);
int common = Math.min(intoSize, fromSize);
for (int i = 0; i < common; i++) {
Item oldValue = mergeInto.get(i);
Item newValue = mergeFrom.get(i);
Item merged = Item.merge(oldValue, newValue);
if (merged != null && !merged.equals(oldValue)) {
if (foobar)
System.out.println("foobar");
mergeInto.set(i, merged);
changed = true;
}
}
if (false) for (int i = common; i < fromSize; i++) {
Item newValue = mergeFrom.get(i);
if (foobar)
System.out.println("foobar");
mergeInto.add(newValue);
changed = true;
}
if (DEBUG2 && changed) {
System.out.println("Merge results:");
System.out.println("updating: " + mergeIntoCopy);
System.out.println(" with: " + mergeFrom);
System.out.println(" gives: " + mergeInto);
}
}
return changed;
}
public void clear() {
stack.clear();
lvValues.clear();
}
boolean encountedTop;
boolean backwardsBranch;
BitSet exceptionHandlers = new BitSet();
private boolean jumpInfoChangedByBackwardsBranch = false;
private Map<Integer, List<Item>> jumpEntries = new HashMap<Integer, List<Item>>();
private Map<Integer, List<Item>> jumpStackEntries = new HashMap<Integer, List<Item>>();
private BitSet jumpEntryLocations = new BitSet();
public void printJumpEntries() {
for(int i=jumpEntryLocations.nextSetBit(0); i>=0; i=jumpEntryLocations.nextSetBit(i+1)) {
List<Item> stack = jumpStackEntries.get(i);
List<Item> locals = jumpEntries.get(i);
if (stack != null)
System.out.printf("%4d: %s::%s%n", i, stack, locals);
else
System.out.printf("%4d: ::%s%n", i, locals);
}
}
public static class JumpInfo {
final Map<Integer, List<Item>> jumpEntries;
final Map<Integer, List<Item>> jumpStackEntries;
final BitSet jumpEntryLocations;
JumpInfo(Map<Integer, List<Item>> jumpEntries, Map<Integer, List<Item>> jumpStackEntries, BitSet jumpEntryLocations) {
this.jumpEntries = jumpEntries;
this.jumpStackEntries = jumpStackEntries;
this.jumpEntryLocations = jumpEntryLocations;
}
public int getNextJump(int pc) {
return jumpEntryLocations.nextSetBit(pc);
}
}
public static class JumpInfoFactory extends edu.umd.cs.findbugs.classfile.engine.bcel.AnalysisFactory<JumpInfo> {
public JumpInfoFactory() {
super("Jump info for opcode stack", JumpInfo.class);
}
public @CheckForNull JumpInfo analyze(IAnalysisCache analysisCache, MethodDescriptor descriptor) throws CheckedAnalysisException {
Method method = analysisCache.getMethodAnalysis(Method.class, descriptor);
JavaClass jclass = getJavaClass(analysisCache, descriptor.getClassDescriptor());
Code code = method.getCode();
if (code == null) {
return null;
}
JumpStackComputation branchAnalysis = new JumpStackComputation(descriptor);
return computeJumpInfo(jclass, method, branchAnalysis);
}
static class JumpStackComputation extends BytecodeScanningDetector {
static final boolean DEBUG = false;
final MethodDescriptor descriptor;
private JumpStackComputation(MethodDescriptor descriptor) {
this.descriptor = descriptor;
}
protected OpcodeStack stack = new OpcodeStack();
public OpcodeStack getStack() {
return stack;
}
@Override
public final void visitCode(Code obj) {
if (!getMethodDescriptor().equals(descriptor))
throw new IllegalStateException();
if (DEBUG) System.out.println(descriptor);
stack.resetForMethodEntry0(this);
super.visitCode(obj);
if (DEBUG) System.out.println();
}
@Override
public void sawOpcode(int seen) {
stack.precomputation(this);
if (DEBUG) System.out.printf("%4d %-15s %s%n", getPC(), OPCODE_NAMES[seen], stack);
try {
stack.sawOpcode(this, seen);
} catch (RuntimeException e) {
throw e;
}
}
}
/**
* @param jclass
* @param method
* @param stack
* @param branchAnalysis
* @return
*/
public static @CheckForNull JumpInfo computeJumpInfo(JavaClass jclass, Method method,
JumpStackComputation branchAnalysis) {
branchAnalysis.setupVisitorForClass(jclass);
XMethod createXMethod = XFactory.createXMethod(jclass, method);
if (!(createXMethod instanceof MethodInfo))
return null;
MethodInfo xMethod = (MethodInfo) createXMethod;
int iteration = 1;
OpcodeStack myStack = branchAnalysis.stack;
if (false)
myStack.learnFrom(myStack.getJumpInfoFromStackMap());
do {
if (DEBUG && iteration > 1 ) {
System.out.println("Iterative jump info for " + xMethod +", iteration " + iteration);
myStack.printJumpEntries();
System.out.println();
}
// myStack.resetForMethodEntry0(ClassName.toSlashedClassName(jclass.getClassName()), method);
branchAnalysis.doVisitMethod(method);
if (xMethod.hasBackBranch() != myStack.backwardsBranch && !myStack.encountedTop) {
AnalysisContext.logError(
String.format("For %s, mismatch on existence of backedge: %s for precomputation, %s for bytecode analysis",
xMethod, xMethod.hasBackBranch(), myStack.backwardsBranch));
}
if (iteration++ > 40) {
AnalysisContext.logError("Iterative jump info didn't converge after " + iteration + " iterations in " + xMethod
+ ", size " + method.getCode().getLength());
break;
}
} while (myStack.isJumpInfoChangedByBackwardsBranch() && myStack.backwardsBranch);
if (iteration > 20&& iteration <= 40) {
AnalysisContext.logError("Iterative jump info converged after " + iteration + " iterations in " + xMethod + ", size " + method.getCode().getLength());
}
return new JumpInfo(myStack.jumpEntries, myStack.jumpStackEntries, myStack.jumpEntryLocations);
}
}
public boolean isJumpTarget(int pc) {
return jumpEntryLocations.get(pc);
}
private void addJumpValue(int from, int target) {
if (DEBUG)
System.out.println("Set jump entry at " + methodName + ":" + target + " pc to " + stack + " : " + lvValues);
if (from >= target)
backwardsBranch = true;
List<Item> atTarget = jumpEntries.get(Integer.valueOf(target));
if (atTarget == null) {
setJumpInfoChangedByBackwardBranch("new target", from, target);
jumpEntries.put(Integer.valueOf(target), new ArrayList<Item>(lvValues));
jumpEntryLocations.set(target);
if (stack.size() > 0) {
jumpStackEntries.put(Integer.valueOf(target), new ArrayList<Item>(stack));
}
} else {
if (mergeLists(atTarget, lvValues, false))
setJumpInfoChangedByBackwardBranch("locals", from, target);
List<Item> stackAtTarget = jumpStackEntries.get(Integer.valueOf(target));
if (stack.size() > 0 && stackAtTarget != null)
if (mergeLists(stackAtTarget, stack, false))
setJumpInfoChangedByBackwardBranch("stack", from, target);
}
if (DEBUG)
System.out.println("merge target for " + methodName + ":" + target + " pc is " + atTarget);
}
private String methodName;
DismantleBytecode v;
public void learnFrom(JumpInfo info) {
if (info == null)
return;
jumpEntries = new HashMap<Integer, List<Item>>(info.jumpEntries);
jumpStackEntries = new HashMap<Integer, List<Item>>(info.jumpStackEntries);
jumpEntryLocations = (BitSet) info.jumpEntryLocations.clone();
}
public void initialize() {
setTop(false);
jumpEntries.clear();
jumpStackEntries.clear();
jumpEntryLocations.clear();
encountedTop = false;
backwardsBranch = false;
lastUpdate.clear();
convertJumpToOneZeroState = convertJumpToZeroOneState = 0;
zeroOneComing = -1;
registerTestedFoundToBeNonnegative = -1;
setReachOnlyByBranch(false);
}
public int resetForMethodEntry(final DismantleBytecode visitor) {
this.v = visitor;
initialize();
int result = resetForMethodEntry0(v);
Code code = v.getMethod().getCode();
if (code == null)
return result;
JumpInfo jump = null;
if (useIterativeAnalysis) {
if (visitor instanceof OpcodeStackDetector.WithCustomJumpInfo) {
jump = ((OpcodeStackDetector.WithCustomJumpInfo) visitor).customJumpInfo();
} else if ((visitor instanceof OpcodeStackDetector) && !((OpcodeStackDetector)visitor).isUsingCustomUserValue()) {
jump = getJumpInfo();
} else {
jump = getJumpInfoFromStackMap();
}
} else {
jump = getJumpInfoFromStackMap();
}
learnFrom(jump);
return result;
}
int nullSafeSize(@CheckForNull Collection<?> c) {
if (c == null)
return 0;
return c.size();
}
private JumpInfo getJumpInfo() {
IAnalysisCache analysisCache = Global.getAnalysisCache();
XMethod xMethod = XFactory.createXMethod(v.getThisClass(), v.getMethod());
if (xMethod instanceof MethodInfo) {
MethodInfo mi = (MethodInfo) xMethod;
if (!mi.hasBackBranch())
return null;
}
try {
return analysisCache.getMethodAnalysis(JumpInfo.class, xMethod.getMethodDescriptor());
} catch (CheckedAnalysisException e) {
AnalysisContext.logError("Error getting jump information", e);
return null;
}
}
private JumpInfoFromStackMap getJumpInfoFromStackMap() {
IAnalysisCache analysisCache = Global.getAnalysisCache();
XMethod xMethod = XFactory.createXMethod(v.getThisClass(), v.getMethod());
if (xMethod instanceof MethodInfo) {
MethodInfo mi = (MethodInfo) xMethod;
if (!mi.hasBackBranch())
return null;
}
try {
return analysisCache.getMethodAnalysis(JumpInfoFromStackMap.class, xMethod.getMethodDescriptor());
} catch (CheckedAnalysisException e) {
AnalysisContext.logError("Error getting jump information from StackMap", e);
return null;
}
}
public void setJumpInfoChangedByBackwardBranch(String kind, int from, int to) {
if (from < to)
return ;
if (DEBUG && !this.isJumpInfoChangedByBackwardsBranch())
System.out.printf("%s jump info at %d changed by jump from %d%n", kind, to, from);
this.setJumpInfoChangedByBackwardsBranch(from,to);
return ;
}
private int resetForMethodEntry0(PreorderVisitor visitor) {
return resetForMethodEntry0(visitor.getClassName(), visitor.getMethod());
}
int resetForMethodEntry0(@SlashedClassName String className, Method m) {
methodName = m.getName();
if (DEBUG)
System.out.println(" --- ");
String signature = m.getSignature();
stack.clear();
lvValues.clear();
top = false;
encountedTop = false;
backwardsBranch = false;
clearJumpInfoChangedByBackwardsBranch();
setReachOnlyByBranch(false);
seenTransferOfControl = false;
exceptionHandlers.clear();
Code code = m.getCode();
if (code != null) {
CodeException[] exceptionTable = code.getExceptionTable();
if (exceptionTable != null)
for (CodeException ex : exceptionTable)
exceptionHandlers.set(ex.getHandlerPC());
}
if (DEBUG)
System.out.println(" --- " + className + " " + m.getName() + " " + signature);
Type[] argTypes = Type.getArgumentTypes(signature);
int reg = 0;
if (!m.isStatic()) {
Item it = Item.initialArgument("L" + className + ";", reg);
setLVValue(reg, it);
reg += it.getSize();
}
for (Type argType : argTypes) {
Item it = Item.initialArgument(argType.getSignature(), reg);
setLVValue(reg, it);
reg += it.getSize();
}
return reg;
}
public int getStackDepth() {
return stack.size();
}
public Item getStackItem(int stackOffset) {
if (stackOffset < 0 || stackOffset >= stack.size()) {
AnalysisContext.logError("Can't get stack offset " + stackOffset + " from " + stack.toString() + " @ " + v.getPC()
+ " in " + v.getFullyQualifiedMethodName(), new IllegalArgumentException(stackOffset
+ " is not a value stack offset"));
return new Item("Lfindbugs/OpcodeStackError;");
}
int tos = stack.size() - 1;
int pos = tos - stackOffset;
try {
return stack.get(pos);
} catch (ArrayIndexOutOfBoundsException e) {
throw new ArrayIndexOutOfBoundsException("Requested item at offset " + stackOffset + " in a stack of size "
+ stack.size() + ", made request for position " + pos);
}
}
private Item pop() {
return stack.remove(stack.size() - 1);
}
public void replace(int stackOffset, Item value) {
if (stackOffset < 0 || stackOffset >= stack.size()) {
AnalysisContext.logError("Can't get replace stack offset " + stackOffset + " from " + stack.toString() + " @ " + v.getPC()
+ " in " + v.getFullyQualifiedMethodName(), new IllegalArgumentException(stackOffset
+ " is not a value stack offset"));
}
int tos = stack.size() - 1;
int pos = tos - stackOffset;
stack.set(pos, value);
}
public void replaceTop(Item newTop) {
pop();
push(newTop);
}
private void pop(int count) {
while ((count--) > 0)
pop();
}
private void push(Item i) {
stack.add(i);
}
private void pushByConstant(DismantleBytecode dbc, Constant c) {
if (c instanceof ConstantClass)
push(new Item("Ljava/lang/Class;", ((ConstantClass) c).getConstantValue(dbc.getConstantPool())));
else if (c instanceof ConstantInteger)
push(new Item("I", Integer.valueOf(((ConstantInteger) c).getBytes())));
else if (c instanceof ConstantString) {
int s = ((ConstantString) c).getStringIndex();
push(new Item("Ljava/lang/String;", getStringFromIndex(dbc, s)));
} else if (c instanceof ConstantFloat)
push(new Item("F", Float.valueOf(((ConstantFloat) c).getBytes())));
else if (c instanceof ConstantDouble)
push(new Item("D", Double.valueOf(((ConstantDouble) c).getBytes())));
else if (c instanceof ConstantLong)
push(new Item("J", Long.valueOf(((ConstantLong) c).getBytes())));
else
throw new UnsupportedOperationException("StaticConstant type not expected");
}
private void pushByLocalObjectLoad(DismantleBytecode dbc, int register) {
Method m = dbc.getMethod();
LocalVariableTable lvt = m.getLocalVariableTable();
if (lvt != null) {
LocalVariable lv = LVTHelper.getLocalVariableAtPC(lvt, register, dbc.getPC());
if (lv != null) {
String signature = lv.getSignature();
pushByLocalLoad(signature, register);
return;
}
}
pushByLocalLoad("Ljava/lang/Object;", register);
}
private void pushByIntMath(DismantleBytecode dbc, int seen, Item lhs, Item rhs) {
Item newValue = new Item("I");
if (lhs == null || rhs == null) {
push(newValue);
return;
}
try {
if (DEBUG)
System.out.println("pushByIntMath " + dbc.getFullyQualifiedMethodName() + " @ " + dbc.getPC() + " : " + lhs
+ OPCODE_NAMES[seen] + rhs);
if (rhs.getConstant() != null && lhs.getConstant() != null) {
int lhsValue = constantToInt(lhs);
int rhsValue = constantToInt(rhs);
if ((seen == IDIV || seen == IREM) && rhsValue == 0) {
push(newValue);
return;
}
switch (seen) {
case IADD:
newValue = new Item("I", lhsValue + rhsValue);
break;
case ISUB:
newValue = new Item("I", lhsValue - rhsValue);
break;
case IMUL:
newValue = new Item("I", lhsValue * rhsValue);
break;
case IDIV:
newValue = new Item("I", lhsValue / rhsValue);
break;
case IREM:
newValue = new Item("I", lhsValue % rhsValue);
break;
case IAND:
newValue = new Item("I", lhsValue & rhsValue);
if ((rhsValue & 0xff) == 0 && rhsValue != 0 || (lhsValue & 0xff) == 0 && lhsValue != 0)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
break;
case IOR:
newValue = new Item("I", lhsValue | rhsValue);
break;
case IXOR:
newValue = new Item("I", lhsValue ^ rhsValue);
break;
case ISHL:
newValue = new Item("I", lhsValue << rhsValue);
if (rhsValue >= 8)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
break;
case ISHR:
newValue = new Item("I", lhsValue >> rhsValue);
break;
case IUSHR:
newValue = new Item("I", lhsValue >>> rhsValue);
}
} else if ((seen == ISHL || seen == ISHR || seen == IUSHR)) {
if (rhs.getConstant() != null) {
int constant = constantToInt(rhs);
if ((constant & 0x1f) == 0)
newValue = new Item(lhs);
else if (seen == ISHL && (constant & 0x1f) >= 8)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
} else if (lhs.getConstant() != null) {
int constant = constantToInt(lhs);
if (constant == 0)
newValue = new Item("I", 0);
}
} else if (lhs.getConstant() != null && seen == IAND) {
int value = constantToInt(lhs);
if (value == 0)
newValue = new Item("I", 0);
else if ((value & 0xff) == 0)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
else if (value >= 0)
newValue.setSpecialKind(Item.NON_NEGATIVE);
} else if (rhs.getConstant() != null && seen == IAND) {
int value = constantToInt(rhs);
if (value == 0)
newValue = new Item("I", 0);
else if ((value & 0xff) == 0)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
else if (value >= 0)
newValue.setSpecialKind(Item.NON_NEGATIVE);
} else if (seen == IAND && lhs.getSpecialKind() == Item.ZERO_MEANS_NULL) {
newValue.setSpecialKind(Item.ZERO_MEANS_NULL);
newValue.setPC(lhs.getPC());
} else if (seen == IAND && rhs.getSpecialKind() == Item.ZERO_MEANS_NULL) {
newValue.setSpecialKind(Item.ZERO_MEANS_NULL);
newValue.setPC(rhs.getPC());
} else if (seen == IOR && lhs.getSpecialKind() == Item.NONZERO_MEANS_NULL) {
newValue.setSpecialKind(Item.NONZERO_MEANS_NULL);
newValue.setPC(lhs.getPC());
} else if (seen == IOR && rhs.getSpecialKind() == Item.NONZERO_MEANS_NULL) {
newValue.setSpecialKind(Item.NONZERO_MEANS_NULL);
newValue.setPC(rhs.getPC());
}
} catch (ArithmeticException e) {
assert true; // ignore it
} catch (RuntimeException e) {
String msg = "Error processing2 " + lhs + OPCODE_NAMES[seen] + rhs + " @ " + dbc.getPC() + " in "
+ dbc.getFullyQualifiedMethodName();
AnalysisContext.logError(msg, e);
}
if (lhs.getSpecialKind() == Item.INTEGER_SUM && rhs.getConstant() != null) {
int rhsValue = constantToInt(rhs);
if (seen == IDIV && rhsValue == 2 || seen == ISHR && rhsValue == 1)
newValue.setSpecialKind(Item.AVERAGE_COMPUTED_USING_DIVISION);
}
if (seen == IADD && newValue.getSpecialKind() == Item.NOT_SPECIAL && lhs.getConstant() == null
&& rhs.getConstant() == null)
newValue.setSpecialKind(Item.INTEGER_SUM);
if (seen == IREM && lhs.getSpecialKind() == Item.HASHCODE_INT)
newValue.setSpecialKind(Item.HASHCODE_INT_REMAINDER);
if (seen == IREM && lhs.getSpecialKind() == Item.RANDOM_INT)
newValue.setSpecialKind(Item.RANDOM_INT_REMAINDER);
if (seen == IREM && lhs.checkForIntegerMinValue()) {
if (rhs.getConstant() != null) {
int rhsValue = constantToInt(rhs);
if (!Util.isPowerOfTwo(rhsValue))
newValue.setSpecialKind(lhs.getSpecialKindForRemainder());
} else
newValue.setSpecialKind(lhs.getSpecialKindForRemainder());
}
if (DEBUG)
System.out.println("push: " + newValue);
newValue.setPC(dbc.getPC());
push(newValue);
}
private void pushByLongMath(int seen, Item lhs, Item rhs) {
Item newValue = new Item("J");
try {
if ((rhs.getConstant() != null) && lhs.getConstant() != null) {
long lhsValue = constantToLong(lhs);
if (seen == LSHL) {
newValue = new Item("J", Long.valueOf(lhsValue << constantToInt(rhs)));
if (constantToInt(rhs) >= 8)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
} else if (seen == LSHR)
newValue = new Item("J", Long.valueOf(lhsValue >> constantToInt(rhs)));
else if (seen == LUSHR)
newValue = new Item("J", Long.valueOf(lhsValue >>> constantToInt(rhs)));
else {
long rhsValue = constantToLong(rhs);
if (seen == LADD)
newValue = new Item("J", Long.valueOf(lhsValue + rhsValue));
else if (seen == LSUB)
newValue = new Item("J", Long.valueOf(lhsValue - rhsValue));
else if (seen == LMUL)
newValue = new Item("J", Long.valueOf(lhsValue * rhsValue));
else if (seen == LDIV)
newValue = new Item("J", Long.valueOf(lhsValue / rhsValue));
else if (seen == LAND) {
newValue = new Item("J", Long.valueOf(lhsValue & rhsValue));
if ((rhsValue & 0xff) == 0 && rhsValue != 0 || (lhsValue & 0xff) == 0 && lhsValue != 0)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
} else if (seen == LOR)
newValue = new Item("J", Long.valueOf(lhsValue | rhsValue));
else if (seen == LXOR)
newValue = new Item("J", Long.valueOf(lhsValue ^ rhsValue));
else if (seen == LREM)
newValue = new Item("J", Long.valueOf(lhsValue % rhsValue));
}
} else if (rhs.getConstant() != null && seen == LSHL && constantToInt(rhs) >= 8)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
else if (lhs.getConstant() != null && seen == LAND && (constantToLong(lhs) & 0xff) == 0)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
else if (rhs.getConstant() != null && seen == LAND && (constantToLong(rhs) & 0xff) == 0)
newValue.setSpecialKind(Item.LOW_8_BITS_CLEAR);
} catch (RuntimeException e) {
// ignore it
}
push(newValue);
}
private void pushByFloatMath(int seen, Item it, Item it2) {
Item result;
@SpecialKind int specialKind = Item.FLOAT_MATH;
if ((it.getConstant() instanceof Float) && it2.getConstant() instanceof Float) {
if (seen == FADD)
result = new Item("F", Float.valueOf(constantToFloat(it2) + constantToFloat(it)));
else if (seen == FSUB)
result = new Item("F", Float.valueOf(constantToFloat(it2) - constantToFloat(it)));
else if (seen == FMUL)
result = new Item("F", Float.valueOf(constantToFloat(it2) * constantToFloat(it)));
else if (seen == FDIV)
result = new Item("F", Float.valueOf(constantToFloat(it2) / constantToFloat(it)));
else if (seen == FREM)
result = new Item("F", Float.valueOf(constantToFloat(it2) % constantToFloat(it)));
else
result = new Item("F");
} else {
result = new Item("F");
if (seen == DDIV)
specialKind = Item.NASTY_FLOAT_MATH;
}
result.setSpecialKind(specialKind);
push(result);
}
private void pushByDoubleMath(int seen, Item it, Item it2) {
Item result;
@SpecialKind int specialKind = Item.FLOAT_MATH;
if ((it.getConstant() instanceof Double) && it2.getConstant() instanceof Double) {
if (seen == DADD)
result = new Item("D", Double.valueOf(constantToDouble(it2) + constantToDouble(it)));
else if (seen == DSUB)
result = new Item("D", Double.valueOf(constantToDouble(it2) - constantToDouble(it)));
else if (seen == DMUL)
result = new Item("D", Double.valueOf(constantToDouble(it2) * constantToDouble(it)));
else if (seen == DDIV)
result = new Item("D", Double.valueOf(constantToDouble(it2) / constantToDouble(it)));
else if (seen == DREM)
result = new Item("D", Double.valueOf(constantToDouble(it2) % constantToDouble(it)));
else
result = new Item("D"); // ?
} else {
result = new Item("D");
if (seen == DDIV)
specialKind = Item.NASTY_FLOAT_MATH;
}
result.setSpecialKind(specialKind);
push(result);
}
private void pushByInvoke(DismantleBytecode dbc, boolean popThis) {
String signature = dbc.getSigConstantOperand();
if (dbc.getNameConstantOperand().equals("<init>") && signature.endsWith(")V") && popThis) {
pop(PreorderVisitor.getNumberArguments(signature));
Item constructed = pop();
if (getStackDepth() > 0) {
Item next = getStackItem(0);
if (constructed.equals(next)) {
next = new Item(next);
next.source = XFactory.createReferencedXMethod(dbc);
next.pc = dbc.getPC();
replace(0, next);
}
}
return;
}
pop(PreorderVisitor.getNumberArguments(signature) + (popThis ? 1 : 0));
pushBySignature(Type.getReturnType(signature).getSignature(), dbc);
}
public Item getItemMethodInvokedOn(DismantleBytecode dbc) {
int opcode = dbc.getOpcode();
switch (opcode) {
case INVOKEVIRTUAL:
case INVOKEINTERFACE:
case INVOKESPECIAL:
String signature = dbc.getSigConstantOperand();
int stackOffset = PreorderVisitor.getNumberArguments(signature);
return getStackItem(stackOffset);
}
throw new IllegalArgumentException("Not visiting an instance method call");
}
private String getStringFromIndex(DismantleBytecode dbc, int i) {
ConstantUtf8 name = (ConstantUtf8) dbc.getConstantPool().getConstant(i);
return name.getBytes();
}
private void pushBySignature(String s, DismantleBytecode dbc) {
if ("V".equals(s))
return;
Item item = new Item(s, (Object) null);
if (dbc != null)
item.setPC(dbc.getPC());
if ("B".equals(s))
item.setSpecialKind(Item.SIGNED_BYTE);
else if ("C".equals(s))
item.setSpecialKind(Item.NON_NEGATIVE);
push(item);
}
private void pushByLocalStore(int register) {
Item it = new Item(pop());
if (it.getRegisterNumber() != register) {
for (Item i : lvValues)
if (i != null) {
if (i.registerNumber == register)
i.registerNumber = -1;
if (i.fieldLoadedFromRegister == register)
i.fieldLoadedFromRegister = -1;
}
for (Item i : stack)
if (i != null) {
if (i.registerNumber == register)
i.registerNumber = -1;
if (i.fieldLoadedFromRegister == register)
i.fieldLoadedFromRegister = -1;
}
}
if (it.registerNumber == -1)
it.registerNumber = register;
setLVValue(register, it);
}
private void pushByLocalLoad(String signature, int register) {
Item oldItem = new Item(getLVValue(register));
Item newItem = oldItem;
if (newItem.signature.equals("Ljava/lang/Object;") && !signature.equals("Ljava/lang/Object;")) {
newItem = new Item(oldItem);
newItem.signature = signature;
}
if (newItem.getRegisterNumber() < 0) {
if (newItem == oldItem)
newItem = new Item(oldItem);
newItem.registerNumber = register;
}
push(newItem);
}
private void setLVValue(int index, Item value) {
int addCount = index - lvValues.size() + 1;
while ((addCount--) > 0)
lvValues.add(null);
if (!useIterativeAnalysis && seenTransferOfControl)
value = Item.merge(value, lvValues.get(index));
lvValues.set(index, value);
}
public Item getLVValue(int index) {
if (index >= lvValues.size())
return new Item();
Item item = lvValues.get(index);
if (item != null)
return item;
return new Item();
}
public int getNumLocalValues() {
return lvValues.size();
}
/**
* @param top
* The top to set.
*/
private void setTop(boolean top) {
if (top) {
if (!this.top)
this.top = true;
} else if (this.top)
this.top = false;
}
/**
* @return Returns the top.
*/
public boolean isTop() {
if (top)
return true;
return false;
}
/**
* @param reachOnlyByBranch
* The reachOnlyByBranch to set.
*/
void setReachOnlyByBranch(boolean reachOnlyByBranch) {
if (reachOnlyByBranch)
setTop(true);
this.reachOnlyByBranch = reachOnlyByBranch;
}
/**
* @return Returns the reachOnlyByBranch.
*/
boolean isReachOnlyByBranch() {
return reachOnlyByBranch;
}
/**
* @return Returns the jumpInfoChangedByBackwardsBranch.
*/
boolean isJumpInfoChangedByBackwardsBranch() {
return jumpInfoChangedByBackwardsBranch;
}
void clearJumpInfoChangedByBackwardsBranch() {
this.jumpInfoChangedByBackwardsBranch = false;
}
/**
* @param jumpInfoChangedByBackwardsBranch The jumpInfoChangedByBackwardsBranch to set.
*/
void setJumpInfoChangedByBackwardsBranch(int from, int to) {
this.jumpInfoChangedByBackwardsBranch = true;
}
}
// vim:ts=4