public class LocalVariablesSorter extends MethodVisitor
MethodVisitor that renumbers local variables in their order of appearance. This adapter
allows one to easily add new local variables to a method. It may be used by inheriting from this
class, but the preferred way of using it is via delegation: the next visitor in the chain can
indeed add new locals when needed by calling newLocal(org.objectweb.asm.Type) on this adapter (this requires a
reference back to this LocalVariablesSorter).| 限定符和类型 | 字段和说明 |
|---|---|
protected int |
firstLocal
Index of the first local variable, after formal parameters.
|
protected int |
nextLocal
Index of the next local variable to be created by
newLocal(org.objectweb.asm.Type). |
api, mv| 限定符 | 构造器和说明 |
|---|---|
protected |
LocalVariablesSorter(int api,
int access,
java.lang.String desc,
MethodVisitor mv)
Creates a new
LocalVariablesSorter. |
|
LocalVariablesSorter(int access,
java.lang.String desc,
MethodVisitor mv)
Creates a new
LocalVariablesSorter. |
| 限定符和类型 | 方法和说明 |
|---|---|
int |
newLocal(Type type)
Creates a new local variable of the given type.
|
protected int |
newLocalMapping(Type type) |
protected void |
setLocalType(int local,
Type type)
Notifies subclasses that a local variable has been added or remapped.
|
protected void |
updateNewLocals(java.lang.Object[] newLocals)
Notifies subclasses that a new stack map frame is being visited.
|
void |
visitFrame(int type,
int nLocal,
java.lang.Object[] local,
int nStack,
java.lang.Object[] stack)
Visits the current state of the local variables and operand stack elements.
|
void |
visitIincInsn(int var,
int increment)
Visits an IINC instruction.
|
void |
visitLocalVariable(java.lang.String name,
java.lang.String desc,
java.lang.String signature,
Label start,
Label end,
int index)
Visits a local variable declaration.
|
void |
visitMaxs(int maxStack,
int maxLocals)
Visits the maximum stack size and the maximum number of local variables of the method.
|
void |
visitVarInsn(int opcode,
int var)
Visits a local variable instruction.
|
visitAnnotation, visitAnnotationDefault, visitAttribute, visitCode, visitEnd, visitFieldInsn, visitInsn, visitIntInsn, visitInvokeDynamicInsn, visitJumpInsn, visitLabel, visitLdcInsn, visitLineNumber, visitLookupSwitchInsn, visitMethodInsn, visitMultiANewArrayInsn, visitParameterAnnotation, visitTableSwitchInsn, visitTryCatchBlock, visitTypeInsnprotected final int firstLocal
protected int nextLocal
newLocal(org.objectweb.asm.Type).public LocalVariablesSorter(int access,
java.lang.String desc,
MethodVisitor mv)
LocalVariablesSorter. Subclasses must not use this constructor.
Instead, they must use the LocalVariablesSorter(int, int, String, MethodVisitor)
version.access - access flags of the adapted method.desc - the method's descriptor (see Type).mv - the method visitor to which this adapter delegates calls.protected LocalVariablesSorter(int api,
int access,
java.lang.String desc,
MethodVisitor mv)
LocalVariablesSorter.api - the ASM API version implemented by this visitor. Must be one of
Opcodes.ASM4.access - access flags of the adapted method.desc - the method's descriptor (see Type).mv - the method visitor to which this adapter delegates calls.public void visitVarInsn(int opcode,
int var)
MethodVisitorvisitVarInsn 在类中 MethodVisitoropcode - 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.public void visitIincInsn(int var,
int increment)
MethodVisitorvisitIincInsn 在类中 MethodVisitorvar - index of the local variable to be incremented.increment - amount to increment the local variable by.public void visitMaxs(int maxStack,
int maxLocals)
MethodVisitorvisitMaxs 在类中 MethodVisitormaxStack - maximum stack size of the method.maxLocals - maximum number of local variables for the method.public void visitLocalVariable(java.lang.String name,
java.lang.String desc,
java.lang.String signature,
Label start,
Label end,
int index)
MethodVisitorvisitLocalVariable 在类中 MethodVisitorname - 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.public void visitFrame(int type,
int nLocal,
java.lang.Object[] local,
int nStack,
java.lang.Object[] stack)
MethodVisitorV1_6. 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.visitFrame 在类中 MethodVisitortype - 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.public int newLocal(Type type)
type - the type of the local variable to be created.protected void updateNewLocals(java.lang.Object[] newLocals)
newLocal(org.objectweb.asm.Type).
This method can update these types in place for the stack map frame being visited. The
default implementation of this method does nothing, i.e. a local variable added with
newLocal(org.objectweb.asm.Type) will have the same type in all stack map frames. But this behavior is not
always the desired one, for instance if a local variable is added in the middle of a
try/catch block: the frame for the exception handler should have a TOP type for this new
local.newLocals - the stack map frame types corresponding to the local variables added with
newLocal(org.objectweb.asm.Type) (and null for the others). The format of this array is the same as
in MethodVisitor.visitFrame(int, int, java.lang.Object[], int, java.lang.Object[]), except that long and double types use two slots.
The types for the current stack map frame must be updated in place in this array.protected void setLocalType(int local,
Type type)
local - a local variable identifier, as returned by newLocal().type - the type of the value being stored in the local variable.protected int newLocalMapping(Type type)