ASM: a very small and fast Java bytecode manipulation framework
Copyright (c) 2000-2007 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 org.objectweb.asm;
A visitor to visit a Java method. The methods of this interface must be
called in the following order: [
visitAnnotationDefault ] (
visitAnnotation |
visitParameterAnnotation |
visitAttribute )* [
visitCode (
visitFrame |
visitXInsn |
visitLabel |
visitTryCatchBlock |
visitLocalVariable |
visitLineNumber)*
visitMaxs ]
visitEnd. In addition, the
visitXInsn
and
visitLabel methods must be called in the sequential order of
the bytecode instructions of the visited code,
visitTryCatchBlock
must be called
before the labels passed as arguments have been
visited, and the
visitLocalVariable and
visitLineNumber
methods must be called
after the labels passed as arguments have been
visited.
Visits the default value of this annotation interface method.
- Returns:
- a visitor to the visit the actual default value of this
annotation interface method, or null if this visitor
is not interested in visiting this default value. The 'name'
parameters passed to the methods of this annotation visitor are
ignored. Moreover, exacly one visit method must be called on this
annotation visitor, followed by visitEnd.
Visits an annotation of this method.
- Parameters:
desc
the class descriptor of the annotation class.visible
true if the annotation is visible at runtime.- Returns:
- a visitor to visit the annotation values, or null if
this visitor is not interested in visiting this annotation.
Visits an annotation of a parameter this method.
- Parameters:
parameter
the parameter index.desc
the class descriptor of the annotation class.visible
true if the annotation is visible at runtime.- Returns:
- a visitor to visit the annotation values, or null if
this visitor is not interested in visiting this annotation.
Visits a non standard attribute of this method.
- Parameters:
attr
an attribute.
Starts the visit of the method's code, if any (i.e. non abstract method).
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 unconditionnal 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
V1_6
.
Packed frames are basically
"deltas" from the state of the previous frame (very first frame is
implicitly defined by the method's parameters and access flags):
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 (nStack
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 (nLocal
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 (nLocals
is 1,
2 or 3). Opcodes.F_FULL
representing complete frame
data.
- Parameters:
type
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.nLocal
the number of local variables in the visited frame.local
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), and uninitialized
types by Label objects (this label designates the NEW instruction
that created this uninitialized value).nStack
the number of operand stack elements in the visited frame.stack
the operand stack types in this frame. This array must not
be modified. Its content has the same format as the "local" array.
Visits a zero operand instruction.
- Parameters:
opcode
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.
Visits an instruction with a single int operand.
- Parameters:
opcode
the opcode of the instruction to be visited. This opcode is
either BIPUSH, SIPUSH or NEWARRAY.operand
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
.
Visits a local variable instruction. A local variable instruction is an
instruction that loads or stores the value of a local variable.
- Parameters:
opcode
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.var
the operand of the instruction to be visited. This operand is
the index of a local variable.
Visits a type instruction. A type instruction is an instruction that
takes the internal name of a class as parameter.
- Parameters:
opcode
the opcode of the type instruction to be visited. This
opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.type
the operand of the instruction to be visited. This operand
must be the internal name of an object or array class (see Type.getInternalName()
).
Visits a field instruction. A field instruction is an instruction that
loads or stores the value of a field of an object.
- Parameters:
opcode
the opcode of the type instruction to be visited. This
opcode is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.owner
the internal name of the field's owner class (see Type.getInternalName()
).name
the field's name.desc
the field's descriptor (see Type
).
Visits a method instruction. A method instruction is an instruction that
invokes a method.
- Parameters:
opcode
the opcode of the type instruction to be visited. This
opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or
INVOKEINTERFACE.owner
the internal name of the method's owner class (see Type.getInternalName()
).name
the method's name.desc
the method's descriptor (see Type
).
Visits a jump instruction. A jump instruction is an instruction that may
jump to another instruction.
- Parameters:
opcode
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
the operand of the instruction to be visited. This operand
is a label that designates the instruction to which the jump
instruction may jump.
Visits a label. A label designates the instruction that will be visited
just after it.
- Parameters:
label
a Label
object.
Visits a LDC instruction.
Visits an IINC instruction.
- Parameters:
var
index of the local variable to be incremented.increment
amount to increment the local variable by.
Visits a TABLESWITCH instruction.
- Parameters:
min
the minimum key value.max
the maximum key value.dflt
beginning of the default handler block.labels
beginnings of the handler blocks. labels[i] is
the beginning of the handler block for the min + i key.
Visits a LOOKUPSWITCH instruction.
- Parameters:
dflt
beginning of the default handler block.keys
the values of the keys.labels
beginnings of the handler blocks. labels[i] is
the beginning of the handler block for the keys[i] key.
Visits a MULTIANEWARRAY instruction.
- Parameters:
desc
an array type descriptor (see Type
).dims
number of dimensions of the array to allocate.
Visits a try catch block.
- Parameters:
start
beginning of the exception handler's scope (inclusive).end
end of the exception handler's scope (exclusive).handler
beginning of the exception handler's code.type
internal name of the type of exceptions handled by the
handler, or null to catch any exceptions (for "finally"
blocks).- Throws:
java.lang.IllegalArgumentException
if one of the labels has already been
visited by this visitor (by the visitLabel
method).
Visits a local variable declaration.
- Parameters:
name
the name of a local variable.desc
the type descriptor of this local variable.signature
the type signature of this local variable. May be
null if the local variable type does not use generic
types.start
the first instruction corresponding to the scope of this
local variable (inclusive).end
the last instruction corresponding to the scope of this local
variable (exclusive).index
the local variable's index.- Throws:
java.lang.IllegalArgumentException
if one of the labels has not already
been visited by this visitor (by the
visitLabel
method).
Visits a line number declaration.
- Parameters:
line
a line number. This number refers to the source file from
which the class was compiled.start
the first instruction corresponding to this line number.- Throws:
java.lang.IllegalArgumentException
if start has not already been
visited by this visitor (by the visitLabel
method).
Visits the maximum stack size and the maximum number of local variables
of the method.
- Parameters:
maxStack
maximum stack size of the method.maxLocals
maximum number of local variables for the method.
Visits the end of the method. This method, which is the last one to be
called, is used to inform the visitor that all the annotations and
attributes of the method have been visited.