public Class StackAwareMethodVisitor

true if stack adjustment is disabled.

A property to disable stack adjustment. Stack adjustment is typically needed when instrumenting other generated code that leaves excess values on the stack. This is also often the case when byte code obfuscation is used.

Pops all values currently on the stack.

Drains the stack to only contain the top value. For this, the value on top of the stack is temporarily stored in the local variable array until all values on the stack are popped off. Subsequently, the top value is pushed back onto the operand stack.

Parameters

store:int

The opcode used for storing the top value.

load:int

The opcode used for loading the top value.

size:StackSize

The size of the value on top of the operand stack.

Returns:int

The minimal size of the local variable array that is required to perform the operation.

Wraps the provided method visitor within a stack aware method visitor.

Parameters

methodVisitor:MethodVisitor

The method visitor to delegate operations to.

instrumentedMethod:MethodDescription

The method description for which this method visitor is applied.

Returns:MethodVisitor

An appropriate

Explicitly registers a label to define a given stack state.

Parameters

label:Label

The label to register a stack state for.

stackSizes:List<StackSize>

The stack sizes to assume when reaching the supplied label.

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitFieldInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitFieldInsn.

Visits a field instruction. A field instruction is an instruction that loads or stores the value of a field of an object.

Parameters

opcode:int

the opcode of the type instruction to be visited. This opcode is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.

owner:String

the internal name of the field's owner class (see Type#getInternalName()).

name:String

the field's name.

descriptor:String

the field's descriptor (see Type).

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitFrame.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitFrame.

Visits the current state of the local variables and operand stack elements. This method must(*) be called just before any instruction i that follows an unconditional branch instruction such as GOTO or THROW, that is the target of a jump instruction, or that starts an exception handler block. The visited types must describe the values of the local variables and of the operand stack elements just before i is executed.

(*) this is mandatory only for classes whose version is greater than or equal to Opcodes#V1_6.

The frames of a method must be given either in expanded form, or in compressed form (all frames must use the same format, i.e. you must not mix expanded and compressed frames within a single method):

• In expanded form, all frames must have the F_NEW type.
• In compressed form, frames are basically "deltas" from the state of the previous frame:
  • Opcodes#F_SAME representing frame with exactly the same locals as the previous frame and with the empty stack.
  • Opcodes#F_SAME1 representing frame with exactly the same locals as the previous frame and with single value on the stack ( numStack is 1 and stack[0] contains value for the type of the stack item).
  • Opcodes#F_APPEND representing frame with current locals are the same as the locals in the previous frame, except that additional locals are defined ( numLocal is 1, 2 or 3 and local elements contains values representing added types).
  • Opcodes#F_CHOP representing frame with current locals are the same as the locals in the previous frame, except that the last 1-3 locals are absent and with the empty stack (numLocal is 1, 2 or 3).
  • Opcodes#F_FULL representing complete frame data.

Parameters

type:int

the type of this stack map frame. Must be Opcodes#F_NEW for expanded frames, or Opcodes#F_FULL, Opcodes#F_APPEND, Opcodes#F_CHOP, Opcodes#F_SAME or Opcodes#F_APPEND, Opcodes#F_SAME1 for compressed frames.

localVariableLength:int

the number of local variables in the visited frame. Long and double values count for one variable.

localVariable:Object[]

the local variable types in this frame. This array must not be modified. Primitive types are represented by Opcodes#TOP, Opcodes#INTEGER, Opcodes#FLOAT, Opcodes#LONG, Opcodes#DOUBLE, Opcodes#NULL or Opcodes#UNINITIALIZED_THIS (long and double are represented by a single element). Reference types are represented by String objects (representing internal names, see Type#getInternalName()), and uninitialized types by Label objects (this label designates the NEW instruction that created this uninitialized value).

stackSize:int

the number of operand stack elements in the visited frame. Long and double values count for one stack element.

stack:Object[]

the operand stack types in this frame. This array must not be modified. Its content has the same format as the "local" array.

Annotations

@Override

@SuppressFBWarnings:RC_REF_COMPARISON_BAD_PRACTICE

justification:ASM models frames by reference identity.

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitInsn.

Visits a zero operand instruction.

Parameters

opcode:int

the opcode of the instruction to be visited. This opcode is either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0, FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD, LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE, POP, POP2, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP, IADD, LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, FDIV, DDIV, IREM, LREM, FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL, LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, I2C, I2S, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN, FRETURN, DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW, MONITORENTER, or MONITOREXIT.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitIntInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitIntInsn.

Visits an instruction with a single int operand.

Parameters

opcode:int

the opcode of the instruction to be visited. This opcode is either BIPUSH, SIPUSH or NEWARRAY.

operand:int

the operand of the instruction to be visited.
When opcode is BIPUSH, operand value should be between Byte.MIN_VALUE and Byte.MAX_VALUE.
When opcode is SIPUSH, operand value should be between Short.MIN_VALUE and Short.MAX_VALUE.
When opcode is NEWARRAY, operand value should be one of Opcodes#T_BOOLEAN, Opcodes#T_CHAR, Opcodes#T_FLOAT, Opcodes#T_DOUBLE, Opcodes#T_BYTE, Opcodes#T_SHORT, Opcodes#T_INT or Opcodes#T_LONG.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitInvokeDynamicInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitInvokeDynamicInsn.

Visits an invokedynamic instruction.

Parameters

name:String

the method's name.

descriptor:String

the method's descriptor (see Type).

bootstrap:Handle

the bootstrap method.

bootstrapArguments:Object[]

the bootstrap method constant arguments. Each argument must be an Integer, Float, Long, Double, String, Type, Handle or ConstantDynamic value. This method is allowed to modify the content of the array so a caller should expect that this array may change.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitJumpInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitJumpInsn.

Visits a jump instruction. A jump instruction is an instruction that may jump to another instruction.

Parameters

opcode:int

the opcode of the type instruction to be visited. This opcode is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ, IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.

label:Label

the operand of the instruction to be visited. This operand is a label that designates the instruction to which the jump instruction may jump.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitLabel.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitLabel.

Visits a label. A label designates the instruction that will be visited just after it.

Parameters

label:Label

a Label object.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitLdcInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitLdcInsn.

Visits a LDC instruction. Note that new constant types may be added in future versions of the Java Virtual Machine. To easily detect new constant types, implementations of this method should check for unexpected constant types, like this:

if (cst instanceof Integer) {
    // ...
} else if (cst instanceof Float) {
    // ...
} else if (cst instanceof Long) {
    // ...
} else if (cst instanceof Double) {
    // ...
} else if (cst instanceof String) {
    // ...
} else if (cst instanceof Type) {
    int sort = ((Type) cst).getSort();
    if (sort == Type.OBJECT) {
        // ...
    } else if (sort == Type.ARRAY) {
        // ...
    } else if (sort == Type.METHOD) {
        // ...
    } else {
        // throw an exception
    }
} else if (cst instanceof Handle) {
    // ...
} else if (cst instanceof ConstantDynamic) {
    // ...
} else {
    // throw an exception
}

Parameters

value:Object

the constant to be loaded on the stack. This parameter must be a non null Integer, a Float, a Long, a Double, a String, a Type of OBJECT or ARRAY sort for .class constants, for classes whose version is 49, a Type of METHOD sort for MethodType, a Handle for MethodHandle constants, for classes whose version is 51 or a ConstantDynamic for a constant dynamic for classes whose version is 55.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitLineNumber.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitLineNumber.

Visits a line number declaration.

Parameters

line:int

a line number. This number refers to the source file from which the class was compiled.

start:Label

the first instruction corresponding to this line number.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitLookupSwitchInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitLookupSwitchInsn.

Visits a LOOKUPSWITCH instruction.

Parameters

defaultOption:Label

beginning of the default handler block.

key:int[]

the values of the keys.

option:Label[]

beginnings of the handler blocks. labels[i] is the beginning of the handler block for the keys[i] key.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitMethodInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitMethodInsn.

Visits a method instruction. A method instruction is an instruction that invokes a method.

Parameters

opcode:int

the opcode of the type instruction to be visited. This opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or INVOKEINTERFACE.

owner:String

the internal name of the method's owner class (see Type#getInternalName()).

name:String

the method's name.

descriptor:String

the method's descriptor (see Type).

isInterface:boolean

if the method's owner class is an interface.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitMultiANewArrayInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitMultiANewArrayInsn.

Visits a MULTIANEWARRAY instruction.

Parameters

descriptor:String

an array type descriptor (see Type).

dimension:int

the number of dimensions of the array to allocate.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitTableSwitchInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitTableSwitchInsn.

Visits a TABLESWITCH instruction.

Parameters

minimum:int

the minimum key value.

maximum:int

the maximum key value.

defaultOption:Label

beginning of the default handler block.

option:Label[]

beginnings of the handler blocks. labels[i] is the beginning of the handler block for the min + i key.

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitTryCatchBlock.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitTryCatchBlock.

Visits a try catch block.

Parameters

start:Label

the beginning of the exception handler's scope (inclusive).

end:Label

the end of the exception handler's scope (exclusive).

handler:Label

the beginning of the exception handler's code.

type:String

the internal name of the type of exceptions handled by the handler (see Type#getInternalName()), or null to catch any exceptions (for "finally" blocks).

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitTypeInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitTypeInsn.

Visits a type instruction. A type instruction is an instruction that takes the internal name of a class as parameter (see Type#getInternalName()).

Parameters

opcode:int

the opcode of the type instruction to be visited. This opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.

type:String

the operand of the instruction to be visited. This operand must be the internal name of an object or array class (see Type#getInternalName()).

Annotations

@Override

Overrides net.bytebuddy.jar.asm.MethodVisitor.visitVarInsn.

Doc from net.bytebuddy.jar.asm.MethodVisitor.visitVarInsn.

Visits a local variable instruction. A local variable instruction is an instruction that loads or stores the value of a local variable.

Parameters

opcode:int

the opcode of the local variable instruction to be visited. This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE, ASTORE or RET.

variable:int

the operand of the instruction to be visited. This operand is the index of a local variable.

Annotations

@Override

@SuppressFBWarnings:SF_SWITCH_NO_DEFAULT

justification:No action required on default option.