Frame

java.lang.Object
- org.springframework.asm.Frame

Direct Known Subclasses:

CurrentFrame
```
class Frame
extends java.lang.Object
```
The input and output stack map frames of a basic block.
Stack map frames are computed in two steps:
- During the visit of each instruction in MethodWriter, the state of the frame at the end of the current basic block is updated by simulating the action of the instruction on the previous state of this so called "output frame".
- After all instructions have been visited, a fix point algorithm is used in MethodWriter to compute the "input frame" of each basic block (i.e. the stack map frame at the beginning of the basic block). See MethodWriter.computeAllFrames().
Output stack map frames are computed relatively to the input frame of the basic block, which is not yet known when output frames are computed. It is therefore necessary to be able to represent abstract types such as "the type at position x in the input frame locals" or "the type at position x from the top of the input frame stack" or even "the type at position x in the input frame, with y more (or less) array dimensions". This explains the rather complicated type format used in this class, explained below.
The local variables and the operand stack of input and output frames contain values called "abstract types" hereafter. An abstract type is represented with 4 fields named DIM, KIND, FLAGS and VALUE, packed in a single int value for better performance and memory efficiency:
```
   =====================================
   |...DIM|KIND|.F|...............VALUE|
   =====================================
 
```
- the DIM field, stored in the 6 most significant bits, is a signed number of array dimensions (from -32 to 31, included). It can be retrieved with DIM_MASK and a right shift of DIM_SHIFT.
- the KIND field, stored in 4 bits, indicates the kind of VALUE used. These 4 bits can be retrieved with KIND_MASK and, without any shift, must be equal to CONSTANT_KIND, REFERENCE_KIND, UNINITIALIZED_KIND, LOCAL_KIND or STACK_KIND.
- the FLAGS field, stored in 2 bits, contains up to 2 boolean flags. Currently only one flag is defined, namely TOP_IF_LONG_OR_DOUBLE_FLAG.
- the VALUE field, stored in the remaining 20 bits, contains either
  - one of the constants ITEM_TOP, ITEM_ASM_BOOLEAN, ITEM_ASM_BYTE, ITEM_ASM_CHAR or ITEM_ASM_SHORT, ITEM_INTEGER, ITEM_FLOAT, ITEM_LONG, ITEM_DOUBLE, ITEM_NULL or ITEM_UNINITIALIZED_THIS, if KIND is equal to CONSTANT_KIND.
  - the index of a Symbol.TYPE_TAG Symbol in the type table of a SymbolTable, if KIND is equal to REFERENCE_KIND.
  - the index of an Symbol.UNINITIALIZED_TYPE_TAG Symbol in the type table of a SymbolTable, if KIND is equal to UNINITIALIZED_KIND.
  - the index of a local variable in the input stack frame, if KIND is equal to LOCAL_KIND.
  - a position relatively to the top of the stack of the input stack frame, if KIND is equal to STACK_KIND,
Output frames can contain abstract types of any kind and with a positive or negative array dimension (and even unassigned types, represented by 0 - which does not correspond to any valid abstract type value). Input frames can only contain CONSTANT_KIND, REFERENCE_KIND or UNINITIALIZED_KIND abstract types of positive or null array dimension. In all cases the type table contains only internal type names (array type descriptors are forbidden - array dimensions must be represented through the DIM field).
The LONG and DOUBLE types are always represented by using two slots (LONG + TOP or DOUBLE + TOP), for local variables as well as in the operand stack. This is necessary to be able to simulate DUPx_y instructions, whose effect would be dependent on the concrete types represented by the abstract types in the stack (which are not always known).
Author:

Eric Bruneton

Field Summary

Fields
Modifier and Type	Field and Description
`(package private) static int`	`APPEND_FRAME`
`private static int`	`ARRAY_OF` The constant to be added to an abstract type to get one with one more array dimension.
`private static int`	`BOOLEAN`
`private static int`	`BYTE`
`private static int`	`CHAR`
`(package private) static int`	`CHOP_FRAME`
`private static int`	`CONSTANT_KIND`
`private static int`	`DIM_MASK`
`private static int`	`DIM_SHIFT`
`private static int`	`DIM_SIZE`
`private static int`	`DOUBLE`
`private static int`	`ELEMENT_OF` The constant to be added to an abstract type to get one with one less array dimension.
`private static int`	`FLAGS_SHIFT`
`private static int`	`FLAGS_SIZE`
`private static int`	`FLOAT`
`(package private) static int`	`FULL_FRAME`
`private int`	`initializationCount` The number of types that are initialized in the basic block.
`private int[]`	`initializations` The abstract types that are initialized in the basic block.
`private int[]`	`inputLocals` The input stack map frame locals.
`private int[]`	`inputStack` The input stack map frame stack.
`private static int`	`INTEGER`
`private static int`	`ITEM_ASM_BOOLEAN`
`private static int`	`ITEM_ASM_BYTE`
`private static int`	`ITEM_ASM_CHAR`
`private static int`	`ITEM_ASM_SHORT`
`(package private) static int`	`ITEM_DOUBLE`
`(package private) static int`	`ITEM_FLOAT`
`(package private) static int`	`ITEM_INTEGER`
`(package private) static int`	`ITEM_LONG`
`(package private) static int`	`ITEM_NULL`
`(package private) static int`	`ITEM_OBJECT`
`(package private) static int`	`ITEM_TOP`
`(package private) static int`	`ITEM_UNINITIALIZED`
`(package private) static int`	`ITEM_UNINITIALIZED_THIS`
`private static int`	`KIND_MASK`
`private static int`	`KIND_SHIFT`
`private static int`	`KIND_SIZE`
`private static int`	`LOCAL_KIND`
`private static int`	`LONG`
`private static int`	`NULL`
`private int[]`	`outputLocals` The output stack map frame locals.
`private int[]`	`outputStack` The output stack map frame stack.
`private short`	`outputStackStart` The start of the output stack, relatively to the input stack.
`private short`	`outputStackTop` The index of the top stack element in `outputStack`.
`(package private) Label`	`owner` The basic block to which these input and output stack map frames correspond.
`private static int`	`REFERENCE_KIND`
`(package private) static int`	`RESERVED`
`(package private) static int`	`SAME_FRAME`
`(package private) static int`	`SAME_FRAME_EXTENDED`
`(package private) static int`	`SAME_LOCALS_1_STACK_ITEM_FRAME`
`(package private) static int`	`SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED`
`private static int`	`SHORT`
`private static int`	`STACK_KIND`
`private static int`	`TOP`
`private static int`	`TOP_IF_LONG_OR_DOUBLE_FLAG` A flag used for LOCAL_KIND and STACK_KIND abstract types, indicating that if the resolved, concrete type is LONG or DOUBLE, TOP should be used instead (because the value has been partially overridden with an xSTORE instruction).
`private static int`	`UNINITIALIZED_KIND`
`private static int`	`UNINITIALIZED_THIS`
`private static int`	`VALUE_MASK`
`private static int`	`VALUE_SIZE`

Constructor Summary

Constructors
Constructor and Description

Frame(Label owner)
Constructs a new Frame.

Constructors
Constructor and Description
`Frame(Label owner)` Constructs a new Frame.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`(package private) void`	`accept(MethodWriter methodWriter)` Makes the given `MethodWriter` visit the input frame of this `Frame`.
`private void`	`addInitializedType(int abstractType)` Adds an abstract type to the list of types on which a constructor is invoked in the basic block.
`(package private) void`	`copyFrom(Frame frame)` Sets this frame to the value of the given frame.
`(package private) void`	`execute(int opcode, int arg, Symbol argSymbol, SymbolTable symbolTable)` Simulates the action of the given instruction on the output stack frame.
`(package private) static int`	`getAbstractTypeFromApiFormat(SymbolTable symbolTable, java.lang.Object type)` Returns the abstract type corresponding to the given public API frame element type.
`private static int`	`getAbstractTypeFromDescriptor(SymbolTable symbolTable, java.lang.String buffer, int offset)` Returns the abstract type corresponding to the given type descriptor.
`(package private) static int`	`getAbstractTypeFromInternalName(SymbolTable symbolTable, java.lang.String internalName)` Returns the abstract type corresponding to the internal name of a class.
`private int`	`getConcreteOutputType(int abstractOutputType, int numStack)` Computes the concrete output type corresponding to a given abstract output type.
`private int`	`getInitializedType(SymbolTable symbolTable, int abstractType)` Returns the "initialized" abstract type corresponding to the given abstract type.
`(package private) int`	`getInputStackSize()`
`private int`	`getLocal(int localIndex)` Returns the abstract type stored at the given local variable index in the output frame.
`(package private) boolean`	`merge(SymbolTable symbolTable, Frame dstFrame, int catchTypeIndex)` Merges the input frame of the given `Frame` with the input and output frames of this `Frame`.
`private static boolean`	`merge(SymbolTable symbolTable, int sourceType, int[] dstTypes, int dstIndex)` Merges the type at the given index in the given abstract type array with the given type.
`private int`	`pop()` Pops an abstract type from the output frame stack and returns its value.
`private void`	`pop(int elements)` Pops the given number of abstract types from the output frame stack.
`private void`	`pop(java.lang.String descriptor)` Pops as many abstract types from the output frame stack as described by the given descriptor.
`private void`	`push(int abstractType)` Pushes the given abstract type on the output frame stack.
`private void`	`push(SymbolTable symbolTable, java.lang.String descriptor)` Pushes the abstract type corresponding to the given descriptor on the output frame stack.
`(package private) static void`	`putAbstractType(SymbolTable symbolTable, int abstractType, ByteVector output)` Put the given abstract type in the given ByteVector, using the JVMS verification_type_info format used in StackMapTable attributes.
`(package private) void`	`setInputFrameFromApiFormat(SymbolTable symbolTable, int numLocal, java.lang.Object[] local, int numStack, java.lang.Object[] stack)` Sets the input frame from the given public API frame description.
`(package private) void`	`setInputFrameFromDescriptor(SymbolTable symbolTable, int access, java.lang.String descriptor, int maxLocals)` Sets the input frame from the given method description.
`private void`	`setLocal(int localIndex, int abstractType)` Replaces the abstract type stored at the given local variable index in the output frame.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SAME_FRAME
```
static final int SAME_FRAME
```
    See Also:
    
    Constant Field Values
  - SAME_LOCALS_1_STACK_ITEM_FRAME
```
static final int SAME_LOCALS_1_STACK_ITEM_FRAME
```
    See Also:
    
    Constant Field Values
  - RESERVED
```
static final int RESERVED
```
    See Also:
    
    Constant Field Values
  - SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED
```
static final int SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED
```
    See Also:
    
    Constant Field Values
  - CHOP_FRAME
```
static final int CHOP_FRAME
```
    See Also:
    
    Constant Field Values
  - SAME_FRAME_EXTENDED
```
static final int SAME_FRAME_EXTENDED
```
    See Also:
    
    Constant Field Values
  - APPEND_FRAME
```
static final int APPEND_FRAME
```
    See Also:
    
    Constant Field Values
  - FULL_FRAME
```
static final int FULL_FRAME
```
    See Also:
    
    Constant Field Values
  - ITEM_TOP
```
static final int ITEM_TOP
```
    See Also:
    
    Constant Field Values
  - ITEM_INTEGER
```
static final int ITEM_INTEGER
```
    See Also:
    
    Constant Field Values
  - ITEM_FLOAT
```
static final int ITEM_FLOAT
```
    See Also:
    
    Constant Field Values
  - ITEM_DOUBLE
```
static final int ITEM_DOUBLE
```
    See Also:
    
    Constant Field Values
  - ITEM_LONG
```
static final int ITEM_LONG
```
    See Also:
    
    Constant Field Values
  - ITEM_NULL
```
static final int ITEM_NULL
```
    See Also:
    
    Constant Field Values
  - ITEM_UNINITIALIZED_THIS
```
static final int ITEM_UNINITIALIZED_THIS
```
    See Also:
    
    Constant Field Values
  - ITEM_OBJECT
```
static final int ITEM_OBJECT
```
    See Also:
    
    Constant Field Values
  - ITEM_UNINITIALIZED
```
static final int ITEM_UNINITIALIZED
```
    See Also:
    
    Constant Field Values
  - ITEM_ASM_BOOLEAN
```
private static final int ITEM_ASM_BOOLEAN
```
    See Also:
    
    Constant Field Values
  - ITEM_ASM_BYTE
```
private static final int ITEM_ASM_BYTE
```
    See Also:
    
    Constant Field Values
  - ITEM_ASM_CHAR
```
private static final int ITEM_ASM_CHAR
```
    See Also:
    
    Constant Field Values
  - ITEM_ASM_SHORT
```
private static final int ITEM_ASM_SHORT
```
    See Also:
    
    Constant Field Values
  - DIM_SIZE
```
private static final int DIM_SIZE
```
    See Also:
    
    Constant Field Values
  - KIND_SIZE
```
private static final int KIND_SIZE
```
    See Also:
    
    Constant Field Values
  - FLAGS_SIZE
```
private static final int FLAGS_SIZE
```
    See Also:
    
    Constant Field Values
  - VALUE_SIZE
```
private static final int VALUE_SIZE
```
    See Also:
    
    Constant Field Values
  - DIM_SHIFT
```
private static final int DIM_SHIFT
```
    See Also:
    
    Constant Field Values
  - KIND_SHIFT
```
private static final int KIND_SHIFT
```
    See Also:
    
    Constant Field Values
  - FLAGS_SHIFT
```
private static final int FLAGS_SHIFT
```
    See Also:
    
    Constant Field Values
  - DIM_MASK
```
private static final int DIM_MASK
```
    See Also:
    
    Constant Field Values
  - KIND_MASK
```
private static final int KIND_MASK
```
    See Also:
    
    Constant Field Values
  - VALUE_MASK
```
private static final int VALUE_MASK
```
    See Also:
    
    Constant Field Values
  - ARRAY_OF
```
private static final int ARRAY_OF
```
    The constant to be added to an abstract type to get one with one more array dimension.
    
    See Also:
    
    Constant Field Values
  - ELEMENT_OF
```
private static final int ELEMENT_OF
```
    The constant to be added to an abstract type to get one with one less array dimension.
    
    See Also:
    
    Constant Field Values
  - CONSTANT_KIND
```
private static final int CONSTANT_KIND
```
    See Also:
    
    Constant Field Values
  - REFERENCE_KIND
```
private static final int REFERENCE_KIND
```
    See Also:
    
    Constant Field Values
  - UNINITIALIZED_KIND
```
private static final int UNINITIALIZED_KIND
```
    See Also:
    
    Constant Field Values
  - LOCAL_KIND
```
private static final int LOCAL_KIND
```
    See Also:
    
    Constant Field Values
  - STACK_KIND
```
private static final int STACK_KIND
```
    See Also:
    
    Constant Field Values
  - TOP_IF_LONG_OR_DOUBLE_FLAG
```
private static final int TOP_IF_LONG_OR_DOUBLE_FLAG
```
    A flag used for LOCAL_KIND and STACK_KIND abstract types, indicating that if the resolved, concrete type is LONG or DOUBLE, TOP should be used instead (because the value has been partially overridden with an xSTORE instruction).
    
    See Also:
    
    Constant Field Values
  - TOP
```
private static final int TOP
```
    See Also:
    
    Constant Field Values
  - BOOLEAN
```
private static final int BOOLEAN
```
    See Also:
    
    Constant Field Values
  - BYTE
```
private static final int BYTE
```
    See Also:
    
    Constant Field Values
  - CHAR
```
private static final int CHAR
```
    See Also:
    
    Constant Field Values
  - SHORT
```
private static final int SHORT
```
    See Also:
    
    Constant Field Values
  - INTEGER
```
private static final int INTEGER
```
    See Also:
    
    Constant Field Values
  - FLOAT
```
private static final int FLOAT
```
    See Also:
    
    Constant Field Values
  - LONG
```
private static final int LONG
```
    See Also:
    
    Constant Field Values
  - DOUBLE
```
private static final int DOUBLE
```
    See Also:
    
    Constant Field Values
  - NULL
```
private static final int NULL
```
    See Also:
    
    Constant Field Values
  - UNINITIALIZED_THIS
```
private static final int UNINITIALIZED_THIS
```
    See Also:
    
    Constant Field Values
  - owner
```
Label owner
```
    The basic block to which these input and output stack map frames correspond.
  - inputLocals
```
private int[] inputLocals
```
    The input stack map frame locals. This is an array of abstract types.
  - inputStack
```
private int[] inputStack
```
    The input stack map frame stack. This is an array of abstract types.
  - outputLocals
```
private int[] outputLocals
```
    The output stack map frame locals. This is an array of abstract types.
  - outputStack
```
private int[] outputStack
```
    The output stack map frame stack. This is an array of abstract types.
  - outputStackStart
```
private short outputStackStart
```
    The start of the output stack, relatively to the input stack. This offset is always negative or null. A null offset means that the output stack must be appended to the input stack. A -n offset means that the first n output stack elements must replace the top n input stack elements, and that the other elements must be appended to the input stack.
  - outputStackTop
```
private short outputStackTop
```
    The index of the top stack element in outputStack.
  - initializationCount
```
private int initializationCount
```
    The number of types that are initialized in the basic block. See initializations.
  - initializations
```
private int[] initializations
```
    The abstract types that are initialized in the basic block. A constructor invocation on an UNINITIALIZED or UNINITIALIZED_THIS abstract type must replace every occurrence of this type in the local variables and in the operand stack. This cannot be done during the first step of the algorithm since, during this step, the local variables and the operand stack types are still abstract. It is therefore necessary to store the abstract types of the constructors which are invoked in the basic block, in order to do this replacement during the second step of the algorithm, where the frames are fully computed. Note that this array can contain abstract types that are relative to the input locals or to the input stack.
- Constructor Detail
  - Frame
```
Frame(Label owner)
```
    Constructs a new Frame.
    
    Parameters:
    
    owner - the basic block to which these input and output stack map frames correspond.
- Method Detail
  - copyFrom
```
final void copyFrom(Frame frame)
```
    Sets this frame to the value of the given frame.
    WARNING: after this method is called the two frames share the same data structures. It is recommended to discard the given frame to avoid unexpected side effects.
    
    Parameters:
    
    frame - The new frame value.
  - getAbstractTypeFromApiFormat
```
static int getAbstractTypeFromApiFormat(SymbolTable symbolTable,
                                        java.lang.Object type)
```
    Returns the abstract type corresponding to the given public API frame element type.
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    type - a frame element type described using the same format as in MethodVisitor.visitFrame(int, int, java.lang.Object[], int, java.lang.Object[]), i.e. either Opcodes.TOP, Opcodes.INTEGER, Opcodes.FLOAT, Opcodes.LONG, Opcodes.DOUBLE, Opcodes.NULL, or Opcodes.UNINITIALIZED_THIS, or the internal name of a class, or a Label designating a NEW instruction (for uninitialized types).
    
    Returns:
    
    the abstract type corresponding to the given frame element type.
  - getAbstractTypeFromInternalName
```
static int getAbstractTypeFromInternalName(SymbolTable symbolTable,
                                           java.lang.String internalName)
```
    Returns the abstract type corresponding to the internal name of a class.
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    internalName - the internal name of a class. This must not be an array type descriptor.
    
    Returns:
    
    the abstract type value corresponding to the given internal name.
  - getAbstractTypeFromDescriptor
```
private static int getAbstractTypeFromDescriptor(SymbolTable symbolTable,
                                                 java.lang.String buffer,
                                                 int offset)
```
    Returns the abstract type corresponding to the given type descriptor.
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    buffer - a string ending with a type descriptor.
    
    offset - the start offset of the type descriptor in buffer.
    
    Returns:
    
    the abstract type corresponding to the given type descriptor.
  - setInputFrameFromDescriptor
```
final void setInputFrameFromDescriptor(SymbolTable symbolTable,
                                       int access,
                                       java.lang.String descriptor,
                                       int maxLocals)
```
    Sets the input frame from the given method description. This method is used to initialize the first frame of a method, which is implicit (i.e. not stored explicitly in the StackMapTable attribute).
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    access - the method's access flags.
    
    descriptor - the method descriptor.
    
    maxLocals - the maximum number of local variables of the method.
  - setInputFrameFromApiFormat
```
final void setInputFrameFromApiFormat(SymbolTable symbolTable,
                                      int numLocal,
                                      java.lang.Object[] local,
                                      int numStack,
                                      java.lang.Object[] stack)
```
    Sets the input frame from the given public API frame description.
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    numLocal - the number of local variables.
    
    local - the local variable types, described using the same format as in MethodVisitor.visitFrame(int, int, java.lang.Object[], int, java.lang.Object[]).
    
    numStack - the number of operand stack elements.
    
    stack - the operand stack types, described using the same format as in MethodVisitor.visitFrame(int, int, java.lang.Object[], int, java.lang.Object[]).
  - getInputStackSize
```
final int getInputStackSize()
```
  - getLocal
```
private int getLocal(int localIndex)
```
    Returns the abstract type stored at the given local variable index in the output frame.
    
    Parameters:
    
    localIndex - the index of the local variable whose value must be returned.
    
    Returns:
    
    the abstract type stored at the given local variable index in the output frame.
  - setLocal
```
private void setLocal(int localIndex,
                      int abstractType)
```
    Replaces the abstract type stored at the given local variable index in the output frame.
    
    Parameters:
    
    localIndex - the index of the output frame local variable that must be set.
    
    abstractType - the value that must be set.
  - push
```
private void push(int abstractType)
```
    Pushes the given abstract type on the output frame stack.
    
    Parameters:
    
    abstractType - an abstract type.
  - push
```
private void push(SymbolTable symbolTable,
                  java.lang.String descriptor)
```
    Pushes the abstract type corresponding to the given descriptor on the output frame stack.
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    descriptor - a type or method descriptor (in which case its return type is pushed).
  - pop
```
private int pop()
```
    Pops an abstract type from the output frame stack and returns its value.
    
    Returns:
    
    the abstract type that has been popped from the output frame stack.
  - pop
```
private void pop(int elements)
```
    Pops the given number of abstract types from the output frame stack.
    
    Parameters:
    
    elements - the number of abstract types that must be popped.
  - pop
```
private void pop(java.lang.String descriptor)
```
    Pops as many abstract types from the output frame stack as described by the given descriptor.
    
    Parameters:
    
    descriptor - a type or method descriptor (in which case its argument types are popped).
  - addInitializedType
```
private void addInitializedType(int abstractType)
```
    Adds an abstract type to the list of types on which a constructor is invoked in the basic block.
    
    Parameters:
    
    abstractType - an abstract type on a which a constructor is invoked.
  - getInitializedType
```
private int getInitializedType(SymbolTable symbolTable,
                               int abstractType)
```
    Returns the "initialized" abstract type corresponding to the given abstract type.
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    abstractType - an abstract type.
    
    Returns:
    
    the REFERENCE_KIND abstract type corresponding to abstractType if it is UNINITIALIZED_THIS or an UNINITIALIZED_KIND abstract type for one of the types on which a constructor is invoked in the basic block. Otherwise returns abstractType.
  - execute
```
void execute(int opcode,
             int arg,
             Symbol argSymbol,
             SymbolTable symbolTable)
```
    Simulates the action of the given instruction on the output stack frame.
    
    Parameters:
    
    opcode - the opcode of the instruction.
    
    arg - the numeric operand of the instruction, if any.
    
    argSymbol - the Symbol operand of the instruction, if any.
    
    symbolTable - the type table to use to lookup and store type Symbol.
  - getConcreteOutputType
```
private int getConcreteOutputType(int abstractOutputType,
                                  int numStack)
```
    Computes the concrete output type corresponding to a given abstract output type.
    
    Parameters:
    
    abstractOutputType - an abstract output type.
    
    numStack - the size of the input stack, used to resolve abstract output types of STACK_KIND kind.
    
    Returns:
    
    the concrete output type corresponding to 'abstractOutputType'.
  - merge
```
final boolean merge(SymbolTable symbolTable,
                    Frame dstFrame,
                    int catchTypeIndex)
```
    Merges the input frame of the given Frame with the input and output frames of this Frame. Returns true if the given frame has been changed by this operation (the input and output frames of this Frame are never changed).
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    dstFrame - the Frame whose input frame must be updated. This should be the frame of a successor, in the control flow graph, of the basic block corresponding to this frame.
    
    catchTypeIndex - if 'frame' corresponds to an exception handler basic block, the type table index of the caught exception type, otherwise 0.
    
    Returns:
    
    true if the input frame of 'frame' has been changed by this operation.
  - merge
```
private static boolean merge(SymbolTable symbolTable,
                             int sourceType,
                             int[] dstTypes,
                             int dstIndex)
```
    Merges the type at the given index in the given abstract type array with the given type. Returns true if the type array has been modified by this operation.
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    sourceType - the abstract type with which the abstract type array element must be merged. This type should be of CONSTANT_KIND, REFERENCE_KIND or UNINITIALIZED_KIND kind, with positive or null array dimensions.
    
    dstTypes - an array of abstract types. These types should be of CONSTANT_KIND, REFERENCE_KIND or UNINITIALIZED_KIND kind, with positive or null array dimensions.
    
    dstIndex - the index of the type that must be merged in dstTypes.
    
    Returns:
    
    true if the type array has been modified by this operation.
  - accept
```
final void accept(MethodWriter methodWriter)
```
    Makes the given MethodWriter visit the input frame of this Frame. The visit is done with the MethodWriter.visitFrameStart(int, int, int), MethodWriter.visitAbstractType(int, int) and MethodWriter.visitFrameEnd() methods.
    
    Parameters:
    
    methodWriter - the MethodWriter that should visit the input frame of this Frame.
  - putAbstractType
```
static void putAbstractType(SymbolTable symbolTable,
                            int abstractType,
                            ByteVector output)
```
    Put the given abstract type in the given ByteVector, using the JVMS verification_type_info format used in StackMapTable attributes.
    
    Parameters:
    
    symbolTable - the type table to use to lookup and store type Symbol.
    
    abstractType - an abstract type, restricted to CONSTANT_KIND, REFERENCE_KIND or UNINITIALIZED_KIND types.
    
    output - where the abstract type must be put.
    
    See Also:
    
    JVMS 4.7.4

Class Frame

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SAME_FRAME

SAME_LOCALS_1_STACK_ITEM_FRAME

RESERVED

SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED

CHOP_FRAME

SAME_FRAME_EXTENDED

APPEND_FRAME

FULL_FRAME

ITEM_TOP

ITEM_INTEGER

ITEM_FLOAT

ITEM_DOUBLE

ITEM_LONG

ITEM_NULL

ITEM_UNINITIALIZED_THIS

ITEM_OBJECT

ITEM_UNINITIALIZED

ITEM_ASM_BOOLEAN

ITEM_ASM_BYTE

ITEM_ASM_CHAR

ITEM_ASM_SHORT

DIM_SIZE

KIND_SIZE

FLAGS_SIZE

VALUE_SIZE

DIM_SHIFT

KIND_SHIFT

FLAGS_SHIFT

DIM_MASK

KIND_MASK

VALUE_MASK

ARRAY_OF

ELEMENT_OF

CONSTANT_KIND

REFERENCE_KIND

UNINITIALIZED_KIND

LOCAL_KIND

STACK_KIND

TOP_IF_LONG_OR_DOUBLE_FLAG

TOP

BOOLEAN

BYTE

CHAR

SHORT

INTEGER

FLOAT

LONG

DOUBLE

NULL

UNINITIALIZED_THIS

owner

inputLocals

inputStack

outputLocals

outputStack

outputStackStart

outputStackTop

initializationCount

initializations

Constructor Detail

Frame

Method Detail

copyFrom

getAbstractTypeFromApiFormat

getAbstractTypeFromInternalName

getAbstractTypeFromDescriptor

setInputFrameFromDescriptor

setInputFrameFromApiFormat

getInputStackSize

getLocal

setLocal

push

push

pop