/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000,2002,2003 INRIA, France Telecom
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package oracle.toplink.libraries.asm.tree.analysis;
import java.util.ArrayList;
import java.util.List;
import oracle.toplink.libraries.asm.Constants;
import oracle.toplink.libraries.asm.Type;
import oracle.toplink.libraries.asm.tree.AbstractInsnNode;
import oracle.toplink.libraries.asm.tree.IincInsnNode;
import oracle.toplink.libraries.asm.tree.MethodInsnNode;
import oracle.toplink.libraries.asm.tree.MultiANewArrayInsnNode;
import oracle.toplink.libraries.asm.tree.VarInsnNode;
/**
* A symbolic execution stack frame. A stack frame contains a set of local
* variable slots, and an operand stack. Warning: long and double values are
* represented by <i>two</i> slots in local variables, and by <i>one</i> slot
* in the operand stack.
*
* @author Eric Bruneton
*/
public class Frame {
/**
* The local variables of this frame.
*/
private Value[] locals;
/**
* The operand stack of this frame.
*/
private Value[] stack;
/**
* The number of elements in the operand stack.
*/
private int top;
/**
* Constructs a new frame with the given size.
*
* @param nLocals the maximum number of local variables of the frame.
* @param nStack the maximum stack size of the frame.
*/
public Frame (final int nLocals, final int nStack) {
this.locals = new Value[nLocals];
this.stack = new Value[nStack];
}
/**
* Constructs a new frame that is identical to the given frame.
*
* @param src a frame.
*/
public Frame (final Frame src) {
this(src.locals.length, src.stack.length);
init(src);
}
/**
* Copies the state of the given frame into this frame.
*
* @param src a frame.
* @return this frame.
*/
public Frame init (final Frame src) {
System.arraycopy(src.locals, 0, locals, 0, locals.length);
System.arraycopy(src.stack, 0, stack, 0, src.top);
top = src.top;
return this;
}
/**
* Returns the maximum number of local variables of this frame.
*
* @return the maximum number of local variables of this frame.
*/
public int getLocals () {
return locals.length;
}
/**
* Returns the value of the given local variable.
*
* @param i a local variable index.
* @return the value of the given local variable.
* @throws AnalyzerException if the variable does not exist.
*/
public Value getLocal (final int i) throws AnalyzerException {
if (i >= locals.length) {
throw new AnalyzerException("Trying to access an inexistant local variable");
}
return locals[i];
}
/**
* Sets the value of the given local variable.
*
* @param i a local variable index.
* @param value the new value of this local variable.
* @throws AnalyzerException if the variable does not exist.
*/
public void setLocal (final int i, final Value value) throws AnalyzerException {
if (i >= locals.length) {
throw new AnalyzerException("Trying to access an inexistant local variable");
}
locals[i] = value;
}
/**
* Returns the number of values in the operand stack of this frame. Long and
* double values are treated as single values.
*
* @return the number of values in the operand stack of this frame.
*/
public int getStackSize () {
return top;
}
/**
* Returns the value of the given operand stack slot.
*
* @param i the index of an operand stack slot.
* @return the value of the given operand stack slot.
* @throws AnalyzerException if the operand stack slot does not exist.
*/
public Value getStack (final int i) throws AnalyzerException {
if (i >= top) {
throw new AnalyzerException("Trying to access an inexistant stack element");
}
return stack[i];
}
/**
* Clears the operand stack of this frame.
*/
public void clearStack () {
top = 0;
}
/**
* Pops a value from the operand stack of this frame.
*
* @return the value that has been popped from the stack.
* @throws AnalyzerException if the operand stack is empty.
*/
public Value pop () throws AnalyzerException {
if (top == 0) {
throw new AnalyzerException("Cannot pop operand off an empty stack.");
}
return stack[--top];
}
/**
* Pushes a value into the operand stack of this frame.
*
* @param value the value that must be pushed into the stack.
* @throws AnalyzerException if the operand stack is full.
*/
public void push (final Value value) throws AnalyzerException {
if (top >= stack.length) {
throw new AnalyzerException("Insufficient maximum stack size.");
}
stack[top++] = value;
}
public void execute (
final AbstractInsnNode insn,
final Interpreter interpreter) throws AnalyzerException
{
Value value1, value2, value3, value4;
List values;
int var;
switch (insn.getOpcode()) {
case Constants.NOP:
break;
case Constants.ACONST_NULL:
case Constants.ICONST_M1:
case Constants.ICONST_0:
case Constants.ICONST_1:
case Constants.ICONST_2:
case Constants.ICONST_3:
case Constants.ICONST_4:
case Constants.ICONST_5:
case Constants.LCONST_0:
case Constants.LCONST_1:
case Constants.FCONST_0:
case Constants.FCONST_1:
case Constants.FCONST_2:
case Constants.DCONST_0:
case Constants.DCONST_1:
case Constants.BIPUSH:
case Constants.SIPUSH:
case Constants.LDC:
push(interpreter.newOperation(insn));
break;
case Constants.ILOAD:
case Constants.LLOAD:
case Constants.FLOAD:
case Constants.DLOAD:
case Constants.ALOAD:
push(interpreter.copyOperation(insn, getLocal(((VarInsnNode)insn).var)));
break;
case Constants.IALOAD:
case Constants.LALOAD:
case Constants.FALOAD:
case Constants.DALOAD:
case Constants.AALOAD:
case Constants.BALOAD:
case Constants.CALOAD:
case Constants.SALOAD:
value2 = pop();
value1 = pop();
push(interpreter.binaryOperation(insn, value1, value2));
break;
case Constants.ISTORE:
case Constants.LSTORE:
case Constants.FSTORE:
case Constants.DSTORE:
case Constants.ASTORE:
value1 = interpreter.copyOperation(insn, pop());
var = ((VarInsnNode)insn).var;
setLocal(var, value1);
if (value1.getSize() == 2) {
setLocal(var + 1, interpreter.newValue(null));
}
if (var > 0 && getLocal(var - 1).getSize() == 2) {
setLocal(var - 1, interpreter.newValue(null));
}
break;
case Constants.IASTORE:
case Constants.LASTORE:
case Constants.FASTORE:
case Constants.DASTORE:
case Constants.AASTORE:
case Constants.BASTORE:
case Constants.CASTORE:
case Constants.SASTORE:
value3 = pop();
value2 = pop();
value1 = pop();
interpreter.ternaryOperation(insn, value1, value2, value3);
break;
case Constants.POP:
if (pop().getSize() == 2) {
throw new AnalyzerException("Illegal use of POP");
}
break;
case Constants.POP2:
if (pop().getSize() == 1) {
if (pop().getSize() != 1) {
throw new AnalyzerException("Illegal use of POP2");
}
}
break;
case Constants.DUP:
value1 = pop();
if (value1.getSize() != 1) {
throw new AnalyzerException("Illegal use of DUP");
}
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value1));
break;
case Constants.DUP_X1:
value1 = pop();
value2 = pop();
if (value1.getSize() != 1 || value2.getSize() != 1) {
throw new AnalyzerException("Illegal use of DUP_X1");
}
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
case Constants.DUP_X2:
value1 = pop();
if (value1.getSize() == 1) {
value2 = pop();
if (value2.getSize() == 1) {
value3 = pop();
if (value3.getSize() == 1) {
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value3));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
} else {
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
}
throw new AnalyzerException("Illegal use of DUP_X2");
case Constants.DUP2:
value1 = pop();
if (value1.getSize() == 1) {
value2 = pop();
if (value2.getSize() == 1) {
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
} else {
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value1));
break;
}
throw new AnalyzerException("Illegal use of DUP2");
case Constants.DUP2_X1:
value1 = pop();
if (value1.getSize() == 1) {
value2 = pop();
if (value2.getSize() == 1) {
value3 = pop();
if (value3.getSize() == 1) {
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value3));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
}
} else {
value2 = pop();
if (value2.getSize() == 1) {
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
}
throw new AnalyzerException("Illegal use of DUP2_X1");
case Constants.DUP2_X2:
value1 = pop();
if (value1.getSize() == 1) {
value2 = pop();
if (value2.getSize() == 1) {
value3 = pop();
if (value3.getSize() == 1) {
value4 = pop();
if (value4.getSize() == 1) {
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value4));
push(interpreter.copyOperation(insn, value3));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
} else {
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value3));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
}
} else {
value2 = pop();
if (value2.getSize() == 1) {
value3 = pop();
if (value3.getSize() == 1) {
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value3));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
} else {
push(interpreter.copyOperation(insn, value1));
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
}
throw new AnalyzerException("Illegal use of DUP2_X2");
case Constants.SWAP:
value2 = pop();
value1 = pop();
if (value1.getSize() != 1 || value2.getSize() != 1) {
throw new AnalyzerException("Illegal use of SWAP");
}
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
case Constants.IADD:
case Constants.LADD:
case Constants.FADD:
case Constants.DADD:
case Constants.ISUB:
case Constants.LSUB:
case Constants.FSUB:
case Constants.DSUB:
case Constants.IMUL:
case Constants.LMUL:
case Constants.FMUL:
case Constants.DMUL:
case Constants.IDIV:
case Constants.LDIV:
case Constants.FDIV:
case Constants.DDIV:
case Constants.IREM:
case Constants.LREM:
case Constants.FREM:
case Constants.DREM:
value2 = pop();
value1 = pop();
push(interpreter.binaryOperation(insn, value1, value2));
break;
case Constants.INEG:
case Constants.LNEG:
case Constants.FNEG:
case Constants.DNEG:
push(interpreter.unaryOperation(insn, pop()));
break;
case Constants.ISHL:
case Constants.LSHL:
case Constants.ISHR:
case Constants.LSHR:
case Constants.IUSHR:
case Constants.LUSHR:
case Constants.IAND:
case Constants.LAND:
case Constants.IOR:
case Constants.LOR:
case Constants.IXOR:
case Constants.LXOR:
value2 = pop();
value1 = pop();
push(interpreter.binaryOperation(insn, value1, value2));
break;
case Constants.IINC:
var = ((IincInsnNode)insn).var;
setLocal(var, interpreter.unaryOperation(insn, getLocal(var)));
break;
case Constants.I2L:
case Constants.I2F:
case Constants.I2D:
case Constants.L2I:
case Constants.L2F:
case Constants.L2D:
case Constants.F2I:
case Constants.F2L:
case Constants.F2D:
case Constants.D2I:
case Constants.D2L:
case Constants.D2F:
case Constants.I2B:
case Constants.I2C:
case Constants.I2S:
push(interpreter.unaryOperation(insn, pop()));
break;
case Constants.LCMP:
case Constants.FCMPL:
case Constants.FCMPG:
case Constants.DCMPL:
case Constants.DCMPG:
value2 = pop();
value1 = pop();
push(interpreter.binaryOperation(insn, value1, value2));
break;
case Constants.IFEQ:
case Constants.IFNE:
case Constants.IFLT:
case Constants.IFGE:
case Constants.IFGT:
case Constants.IFLE:
interpreter.unaryOperation(insn, pop());
break;
case Constants.IF_ICMPEQ:
case Constants.IF_ICMPNE:
case Constants.IF_ICMPLT:
case Constants.IF_ICMPGE:
case Constants.IF_ICMPGT:
case Constants.IF_ICMPLE:
case Constants.IF_ACMPEQ:
case Constants.IF_ACMPNE:
value2 = pop();
value1 = pop();
interpreter.binaryOperation(insn, value1, value2);
break;
case Constants.GOTO:
break;
case Constants.JSR:
push(interpreter.newOperation(insn));
break;
case Constants.RET:
break;
case Constants.TABLESWITCH:
case Constants.LOOKUPSWITCH:
case Constants.IRETURN:
case Constants.LRETURN:
case Constants.FRETURN:
case Constants.DRETURN:
case Constants.ARETURN:
interpreter.unaryOperation(insn, pop());
break;
case Constants.RETURN:
break;
case Constants.GETSTATIC:
push(interpreter.newOperation(insn));
break;
case Constants.PUTSTATIC:
interpreter.unaryOperation(insn, pop());
break;
case Constants.GETFIELD:
push(interpreter.unaryOperation(insn, pop()));
break;
case Constants.PUTFIELD:
value2 = pop();
value1 = pop();
interpreter.binaryOperation(insn, value1, value2);
break;
case Constants.INVOKEVIRTUAL:
case Constants.INVOKESPECIAL:
case Constants.INVOKESTATIC:
case Constants.INVOKEINTERFACE:
values = new ArrayList();
String desc = ((MethodInsnNode)insn).desc;
for (int i = Type.getArgumentTypes(desc).length; i > 0; --i) {
values.add(0, pop());
}
if (insn.getOpcode() != Constants.INVOKESTATIC) {
values.add(0, pop());
}
if (Type.getReturnType(desc) == Type.VOID_TYPE) {
interpreter.naryOperation(insn, values);
} else {
push(interpreter.naryOperation(insn, values));
}
break;
case Constants.NEW:
push(interpreter.newOperation(insn));
break;
case Constants.NEWARRAY:
case Constants.ANEWARRAY:
case Constants.ARRAYLENGTH:
push(interpreter.unaryOperation(insn, pop()));
break;
case Constants.ATHROW:
interpreter.unaryOperation(insn, pop());
break;
case Constants.CHECKCAST:
case Constants.INSTANCEOF:
push(interpreter.unaryOperation(insn, pop()));
break;
case Constants.MONITORENTER:
case Constants.MONITOREXIT:
interpreter.unaryOperation(insn, pop());
break;
case Constants.MULTIANEWARRAY:
values = new ArrayList();
for (int i = ((MultiANewArrayInsnNode)insn).dims; i > 0; --i) {
values.add(0, pop());
}
push(interpreter.naryOperation(insn, values));
break;
case Constants.IFNULL:
case Constants.IFNONNULL:
interpreter.unaryOperation(insn, pop());
break;
default:
throw new RuntimeException("Illegal opcode");
}
}
/**
* Merges this frame with the given frame.
*
* @param frame a frame.
* @param interpreter the interpreter used to merge values.
* @return <tt>true</tt> if this frame has been changed as a result of the
* merge operation, or <tt>false</tt> otherwise.
* @throws AnalyzerException if the frames have incompatible sizes.
*/
public boolean merge (final Frame frame, final Interpreter interpreter)
throws AnalyzerException
{
if (top != frame.top) {
throw new AnalyzerException("Incompatible stack heights");
}
boolean changes = false;
for (int i = 0; i < locals.length; ++i) {
Value v = interpreter.merge(locals[i], frame.locals[i]);
if (v != locals[i]) {
locals[i] = v;
changes |= true;
}
}
for (int i = 0; i < top; ++i) {
Value v = interpreter.merge(stack[i], frame.stack[i]);
if (v != stack[i]) {
stack[i] = v;
changes |= true;
}
}
return changes;
}
/**
* Merges this frame with the given frame (case of a RET instruction).
* @param frame a frame
* @param access the local variables that have been accessed by the
* subroutine to which the RET instruction corresponds.
* @return <tt>true</tt> if this frame has been changed as a result of the
* merge operation, or <tt>false</tt> otherwise.
*/
public boolean merge (final Frame frame, final boolean[] access) {
boolean changes = false;
for (int i = 0; i < locals.length; ++i) {
if (!access[i] && !locals[i].equals(frame.locals[i])) {
locals[i] = frame.locals[i];
changes = true;
}
}
return changes;
}
/**
* Returns a string representation of this frame.
*
* @return a string representation of this frame.
*/
public String toString () {
StringBuffer b = new StringBuffer();
for (int i = 0; i < locals.length; ++i) {
b.append(locals[i]);
}
b.append(' ');
for (int i = 0; i < top; ++i) {
b.append(stack[i].toString());
}
return b.toString();
}
}
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