📄 codewriter.java
字号:
NA, //ASTORE_2, // -
NA, //ASTORE_3, // -
-3, //IASTORE, // visitInsn
-4, //LASTORE, // -
-3, //FASTORE, // -
-4, //DASTORE, // -
-3, //AASTORE, // -
-3, //BASTORE, // -
-3, //CASTORE, // -
-3, //SASTORE, // -
-1, //POP, // -
-2, //POP2, // -
1, //DUP, // -
1, //DUP_X1, // -
1, //DUP_X2, // -
2, //DUP2, // -
2, //DUP2_X1, // -
2, //DUP2_X2, // -
0, //SWAP, // -
-1, //IADD, // -
-2, //LADD, // -
-1, //FADD, // -
-2, //DADD, // -
-1, //ISUB, // -
-2, //LSUB, // -
-1, //FSUB, // -
-2, //DSUB, // -
-1, //IMUL, // -
-2, //LMUL, // -
-1, //FMUL, // -
-2, //DMUL, // -
-1, //IDIV, // -
-2, //LDIV, // -
-1, //FDIV, // -
-2, //DDIV, // -
-1, //IREM, // -
-2, //LREM, // -
-1, //FREM, // -
-2, //DREM, // -
0, //INEG, // -
0, //LNEG, // -
0, //FNEG, // -
0, //DNEG, // -
-1, //ISHL, // -
-1, //LSHL, // -
-1, //ISHR, // -
-1, //LSHR, // -
-1, //IUSHR, // -
-1, //LUSHR, // -
-1, //IAND, // -
-2, //LAND, // -
-1, //IOR, // -
-2, //LOR, // -
-1, //IXOR, // -
-2, //LXOR, // -
0, //IINC, // visitIincInsn
1, //I2L, // visitInsn
0, //I2F, // -
1, //I2D, // -
-1, //L2I, // -
-1, //L2F, // -
0, //L2D, // -
0, //F2I, // -
1, //F2L, // -
1, //F2D, // -
-1, //D2I, // -
0, //D2L, // -
-1, //D2F, // -
0, //I2B, // -
0, //I2C, // -
0, //I2S, // -
-3, //LCMP, // -
-1, //FCMPL, // -
-1, //FCMPG, // -
-3, //DCMPL, // -
-3, //DCMPG, // -
-1, //IFEQ, // visitJumpInsn
-1, //IFNE, // -
-1, //IFLT, // -
-1, //IFGE, // -
-1, //IFGT, // -
-1, //IFLE, // -
-2, //IF_ICMPEQ, // -
-2, //IF_ICMPNE, // -
-2, //IF_ICMPLT, // -
-2, //IF_ICMPGE, // -
-2, //IF_ICMPGT, // -
-2, //IF_ICMPLE, // -
-2, //IF_ACMPEQ, // -
-2, //IF_ACMPNE, // -
0, //GOTO, // -
1, //JSR, // -
0, //RET, // visitVarInsn
-1, //TABLESWITCH, // visiTableSwitchInsn
-1, //LOOKUPSWITCH, // visitLookupSwitch
-1, //IRETURN, // visitInsn
-2, //LRETURN, // -
-1, //FRETURN, // -
-2, //DRETURN, // -
-1, //ARETURN, // -
0, //RETURN, // -
NA, //GETSTATIC, // visitFieldInsn
NA, //PUTSTATIC, // -
NA, //GETFIELD, // -
NA, //PUTFIELD, // -
NA, //INVOKEVIRTUAL, // visitMethodInsn
NA, //INVOKESPECIAL, // -
NA, //INVOKESTATIC, // -
NA, //INVOKEINTERFACE, // -
NA, //UNUSED, // NOT VISITED
1, //NEW, // visitTypeInsn
0, //NEWARRAY, // visitIntInsn
0, //ANEWARRAY, // visitTypeInsn
0, //ARRAYLENGTH, // visitInsn
NA, //ATHROW, // -
0, //CHECKCAST, // visitTypeInsn
0, //INSTANCEOF, // -
-1, //MONITORENTER, // visitInsn
-1, //MONITOREXIT, // -
NA, //WIDE, // NOT VISITED
NA, //MULTIANEWARRAY, // visitMultiANewArrayInsn
-1, //IFNULL, // visitJumpInsn
-1, //IFNONNULL, // -
NA, //GOTO_W, // -
NA, //JSR_W, // -
};
for (i = 0; i < b.length; ++i) {
System.err.print((char)('E' + b[i]));
}
System.err.println();
*/
}
// --------------------------------------------------------------------------
// Constructor
// --------------------------------------------------------------------------
/**
* Constructs a CodeWriter.
*
* @param cw the class writer in which the method must be added.
* @param computeMaxs <tt>true</tt> if the maximum stack size and number of
* local variables must be automatically computed.
*/
protected CodeWriter (final ClassWriter cw, final boolean computeMaxs) {
if (cw.firstMethod == null) {
cw.firstMethod = this;
} else {
cw.lastMethod.next = this;
}
cw.lastMethod = this;
this.cw = cw;
this.computeMaxs = computeMaxs;
if (computeMaxs) {
// pushes the first block onto the stack of blocks to be visited
currentBlock = new Label();
currentBlock.pushed = true;
blockStack = currentBlock;
}
}
/**
* Initializes this CodeWriter to define the bytecode of the specified method.
*
* @param access the method's access flags (see {@link Constants}).
* @param name the method's name.
* @param desc the method's descriptor (see {@link Type Type}).
* @param exceptions the internal names of the method's exceptions. May be
* <tt>null</tt>.
* @param attrs the non standard attributes of the method.
*/
protected void init (
final int access,
final String name,
final String desc,
final String[] exceptions,
final Attribute attrs)
{
this.access = access;
this.name = cw.newUTF8(name);
this.desc = cw.newUTF8(desc);
if (exceptions != null && exceptions.length > 0) {
exceptionCount = exceptions.length;
this.exceptions = new int[exceptionCount];
for (int i = 0; i < exceptionCount; ++i) {
this.exceptions[i] = cw.newClass(exceptions[i]);
}
}
this.attrs = attrs;
if (computeMaxs) {
// updates maxLocals
int size = getArgumentsAndReturnSizes(desc) >> 2;
if ((access & Constants.ACC_STATIC) != 0) {
--size;
}
if (size > maxLocals) {
maxLocals = size;
}
}
}
// --------------------------------------------------------------------------
// Implementation of the CodeVisitor interface
// --------------------------------------------------------------------------
public void visitInsn (final int opcode) {
if (computeMaxs) {
// updates current and max stack sizes
int size = stackSize + SIZE[opcode];
if (size > maxStackSize) {
maxStackSize = size;
}
stackSize = size;
// if opcode == ATHROW or xRETURN, ends current block (no successor)
if ((opcode >= Constants.IRETURN && opcode <= Constants.RETURN) ||
opcode == Constants.ATHROW)
{
if (currentBlock != null) {
currentBlock.maxStackSize = maxStackSize;
currentBlock = null;
}
}
}
// adds the instruction to the bytecode of the method
code.putByte(opcode);
}
public void visitIntInsn (final int opcode, final int operand) {
if (computeMaxs && opcode != Constants.NEWARRAY) {
// updates current and max stack sizes only if opcode == NEWARRAY
// (stack size variation = 0 for BIPUSH or SIPUSH)
int size = stackSize + 1;
if (size > maxStackSize) {
maxStackSize = size;
}
stackSize = size;
}
// adds the instruction to the bytecode of the method
if (opcode == Constants.SIPUSH) {
code.put12(opcode, operand);
} else { // BIPUSH or NEWARRAY
code.put11(opcode, operand);
}
}
public void visitVarInsn (final int opcode, final int var) {
if (computeMaxs) {
// updates current and max stack sizes
if (opcode == Constants.RET) {
// no stack change, but end of current block (no successor)
if (currentBlock != null) {
currentBlock.maxStackSize = maxStackSize;
currentBlock = null;
}
} else { // xLOAD or xSTORE
int size = stackSize + SIZE[opcode];
if (size > maxStackSize) {
maxStackSize = size;
}
stackSize = size;
}
// updates max locals
int n;
if (opcode == Constants.LLOAD || opcode == Constants.DLOAD ||
opcode == Constants.LSTORE || opcode == Constants.DSTORE)
{
n = var + 2;
} else {
n = var + 1;
}
if (n > maxLocals) {
maxLocals = n;
}
}
// adds the instruction to the bytecode of the method
if (var < 4 && opcode != Constants.RET) {
int opt;
if (opcode < Constants.ISTORE) {
opt = 26 /*ILOAD_0*/ + ((opcode - Constants.ILOAD) << 2) + var;
} else {
opt = 59 /*ISTORE_0*/ + ((opcode - Constants.ISTORE) << 2) + var;
}
code.putByte(opt);
} else if (var >= 256) {
code.putByte(196 /*WIDE*/).put12(opcode, var);
} else {
code.put11(opcode, var);
}
}
public void visitTypeInsn (final int opcode, final String desc) {
if (computeMaxs && opcode == Constants.NEW) {
// updates current and max stack sizes only if opcode == NEW
// (stack size variation = 0 for ANEWARRAY, CHECKCAST, INSTANCEOF)
int size = stackSize + 1;
if (size > maxStackSize) {
maxStackSize = size;
}
stackSize = size;
}
// adds the instruction to the bytecode of the method
code.put12(opcode, cw.newClass(desc));
}
public void visitFieldInsn (
final int opcode,
final String owner,
final String name,
final String desc)
{
if (computeMaxs) {
int size;
// computes the stack size variation
char c = desc.charAt(0);
switch (opcode) {
case Constants.GETSTATIC:
size = stackSize + (c == 'D' || c == 'J' ? 2 : 1);
break;
case Constants.PUTSTATIC:
size = stackSize + (c == 'D' || c == 'J' ? -2 : -1);
break;
case Constants.GETFIELD:
size = stackSize + (c == 'D' || c == 'J' ? 1 : 0);
break;
//case Constants.PUTFIELD:
default:
size = stackSize + (c == 'D' || c == 'J' ? -3 : -2);
break;
}
// updates current and max stack sizes
if (size > maxStackSize) {
maxStackSize = size;
}
stackSize = size;
}
// adds the instruction to the bytecode of the method
code.put12(opcode, cw.newField(owner, name, desc));
}
public void visitMethodInsn (
final int opcode,
final String owner,
final String name,
final String desc)
{
boolean itf = opcode == Constants.INVOKEINTERFACE;
Item i = cw.newMethodItem(owner, name, desc, itf);
int argSize = i.intVal;
if (computeMaxs) {
// computes the stack size variation. In order not to recompute several
// times this variation for the same Item, we use the intVal field of
// this item to store this variation, once it has been computed. More
// precisely this intVal field stores the sizes of the arguments and of
// the return value corresponding to desc.
if (argSize == 0) {
// the above sizes have not been computed yet, so we compute them...
argSize = getArgumentsAndReturnSizes(desc);
// ... and we save them in order not to recompute them in the future
i.intVal = argSize;
}
int size;
if (opcode == Constants.INVOKESTATIC) {
size = stackSize - (argSize >> 2) + (argSize & 0x03) + 1;
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