javassist.bytecode
Class StackMap

java.lang.Object
  extended by javassist.bytecode.AttributeInfo
      extended by javassist.bytecode.StackMap

public class StackMap
extends AttributeInfo

Another stack_map attribute defined in CLDC 1.1 for J2ME.

This is an entry in the attributes table of a Code attribute. It was introduced by J2ME CLDC 1.1 (JSR 139) for pre-verification.

According to the CLDC specification, the sizes of some fields are not 16bit but 32bit if the code size is more than 64K or the number of the local variables is more than 64K. However, for the J2ME CLDC technology, they are always 16bit. The implementation of the StackMap class assumes they are 16bit.

Since:
3.12
See Also:
MethodInfo.doPreverify, StackMapTable

Nested Class Summary
static class StackMap.Walker
          A code walker for a StackMap attribute.
static class StackMap.Writer
          Internal use only.
 
Field Summary
static int DOUBLE
          Double_variable_info.tag.
static int FLOAT
          Float_variable_info.tag.
static int INTEGER
          Integer_variable_info.tag.
static int LONG
          Long_variable_info.tag.
static int NULL
          Null_variable_info.tag.
static int OBJECT
          Object_variable_info.tag.
static java.lang.String tag
          The name of this attribute "StackMap".
static int THIS
          UninitializedThis_variable_info.tag.
static int TOP
          Top_variable_info.tag.
static int UNINIT
          Uninitialized_variable_info.tag.
 
Method Summary
 AttributeInfo copy(ConstPool newCp, java.util.Map classnames)
          Makes a copy.
 void insertLocal(int index, int tag, int classInfo)
          Updates this stack map table when a new local variable is inserted for a new parameter.
 int numOfEntries()
          Returns number_of_entries.
 void print(java.io.PrintWriter out)
          Prints this stack map.
 void removeNew(int where)
          Undocumented method.
 
Methods inherited from class javassist.bytecode.AttributeInfo
get, getConstPool, getName, length, set
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

tag

public static final java.lang.String tag
The name of this attribute "StackMap".

See Also:
Constant Field Values

TOP

public static final int TOP
Top_variable_info.tag.

See Also:
Constant Field Values

INTEGER

public static final int INTEGER
Integer_variable_info.tag.

See Also:
Constant Field Values

FLOAT

public static final int FLOAT
Float_variable_info.tag.

See Also:
Constant Field Values

DOUBLE

public static final int DOUBLE
Double_variable_info.tag.

See Also:
Constant Field Values

LONG

public static final int LONG
Long_variable_info.tag.

See Also:
Constant Field Values

NULL

public static final int NULL
Null_variable_info.tag.

See Also:
Constant Field Values

THIS

public static final int THIS
UninitializedThis_variable_info.tag.

See Also:
Constant Field Values

OBJECT

public static final int OBJECT
Object_variable_info.tag.

See Also:
Constant Field Values

UNINIT

public static final int UNINIT
Uninitialized_variable_info.tag.

See Also:
Constant Field Values
Method Detail

numOfEntries

public int numOfEntries()
Returns number_of_entries.


copy

public AttributeInfo copy(ConstPool newCp,
                          java.util.Map classnames)
Makes a copy.

Overrides:
copy in class AttributeInfo
Parameters:
newCp - the constant pool table used by the new copy.
classnames - pairs of replaced and substituted class names.

insertLocal

public void insertLocal(int index,
                        int tag,
                        int classInfo)
                 throws BadBytecode
Updates this stack map table when a new local variable is inserted for a new parameter.

Parameters:
index - the index of the added local variable.
tag - the type tag of that local variable. It is available by StackMapTable.typeTagOf(char).
classInfo - the index of the CONSTANT_Class_info structure in a constant pool table. This should be zero unless the tag is ITEM_Object.
Throws:
BadBytecode
See Also:
CtBehavior.addParameter(javassist.CtClass), StackMapTable.typeTagOf(char), ConstPool

removeNew

public void removeNew(int where)
               throws CannotCompileException
Undocumented method. Do not use; internal-use only.

This method is for javassist.convert.TransformNew. It is called to update the stack map when the NEW opcode (and the following DUP) is removed.

Parameters:
where - the position of the removed NEW opcode.
Throws:
CannotCompileException

print

public void print(java.io.PrintWriter out)
Prints this stack map.



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Copyright (C) 1999-2010 Shigeru Chiba. All Rights Reserved.