Class StackMapData

java.lang.Object

org.openjdk.asmtools.jasm.StackMapData

All Implemented Interfaces:

DataWriter

public class StackMapData
extends Object
implements DataWriter

4.7.4. The StackMapTable Attribute

StackMapTable_attribute { u2 attribute_name_index; u4 attribute_length; u2 number_of_entries; stack_map_entry entries[number_of_entries]; }

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	StackMapData.StackMapItemTagged	verification_type_info: Top_variable_info, Integer_variable_info, Float_variable_info, Null_variable_info, UninitializedThis_variable_info, Long_variable_info, Double_variable_info Common format: *_info { u1 tag = ITEM_*; // from 0 to 6 }
static class	StackMapData.StackMapItemTaggedPointer	verification_type_info: Object_variable_info, Uninitialized_variable_info Common Format: *_info { u1 tag = ITEM_*; // from 7 to 8 u2 cpool_index/offset; }

Field Summary

Fields

Modifier and Type	Field	Description
private StackMap.EntryType	entryType
(package private) final JasmEnvironment	environment
(package private) final boolean	hasStackMapTable
(package private) DataVector<? extends Indexer>	localsMap
private int	offset
private int	pc
private long	scannerPosition
(package private) DataVector<? extends Indexer>	stackMap
(package private) static final int	UNDEFINED
(package private) DataVector<? extends Indexer>	unsetFields

Constructor Summary

Constructors

Constructor	Description
StackMapData(JasmEnvironment environment, boolean hasStackMapTable)	In a class file whose version number is 50.0 or above, if a method's Code attribute does not have a StackMapTable attribute, it has an implicit stack map attribute (§4.10.1).

Method Summary

Modifier and Type	Method	Description
(package private) JasmTokens.Token	checkIntegrity()	Checks whether all fields corresponding to the current frame type are set.
StackMap.EntryType	getFrameType()
int	getLength()
boolean	isCountable()
(package private) boolean	isFrameTypeSet()	Checks whether a method's Code attribute has a StackMapTable attribute.
private boolean	isFull(DataVector<?>... maps)
(package private) boolean	isWrapper()	The early_larval_frame wraps a base_frame.
(package private) StackMapData	setOffset(int offset)
(package private) StackMapData	setOffset(StackMapData prevFrame)
(package private) StackMapData	setPC(int pc)
(package private) StackMapData	setScannerPosition(long scannerPosition)
(package private) StackMapData	setStackFrameType(int stackFrameTypeValue)	Sets Stack Frame type by number in table presentation: frame_type = 252
(package private) StackMapData	setStackFrameTypeByName(String stackFrameTypeName)
void	write(CheckedDataOutputStream out)

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

UNDEFINED

static final int UNDEFINED

See Also:

• Constant Field Values

environment

final JasmEnvironment environment

scannerPosition

private long scannerPosition

hasStackMapTable

final boolean hasStackMapTable

pc

private int pc

offset

private int offset

entryType

private StackMap.EntryType entryType

localsMap

DataVector<? extends Indexer> localsMap

stackMap

DataVector<? extends Indexer> stackMap

unsetFields

DataVector<? extends Indexer> unsetFields

Constructor Details

StackMapData

StackMapData(JasmEnvironment environment,
 boolean hasStackMapTable)

In a class file whose version number is 50.0 or above, if a method's Code attribute does not have a StackMapTable attribute, it has an implicit stack map attribute (§4.10.1). This implicit stack map attribute is equivalent to a StackMapTable attribute with number_of_entries equal to zero.

Parameters:

hasStackMapTable - false if a method's Code attribute does not have a StackMapTable attribute

Method Details

setOffset

StackMapData setOffset(StackMapData prevFrame)

setOffset

StackMapData setOffset(int offset)

setPC

StackMapData setPC(int pc)

setStackFrameTypeByName

StackMapData setStackFrameTypeByName(String stackFrameTypeName)

setStackFrameType

StackMapData setStackFrameType(int stackFrameTypeValue)

Sets Stack Frame type by number in table presentation: frame_type = 252

Parameters:

stackFrameTypeValue - frame type tag

Returns:

StackMapData object

setScannerPosition

StackMapData setScannerPosition(long scannerPosition)

isFrameTypeSet

boolean isFrameTypeSet()

Checks whether a method's Code attribute has a StackMapTable attribute.

Returns:

true if a method's Code attribute has a StackMapTable attribute.

isWrapper

boolean isWrapper()

The early_larval_frame wraps a base_frame. As a wrapper, it doesn't supply the offset_delta.

Returns:

true if the StackMapData is a base_frame wrapper.

isCountable

public boolean isCountable()

Specified by:

isCountable in interface DataWriter

checkIntegrity

JasmTokens.Token checkIntegrity()

Checks whether all fields corresponding to the current frame type are set.

Returns:

null if all fields are sufficiently valid to be written for the current stack map entry otherwise expected token

isFull

private boolean isFull(DataVector<?>... maps)

getLength

public int getLength()

Specified by:

getLength in interface DataWriter

write

public void write(CheckedDataOutputStream out)
           throws IOException

Specified by:

write in interface DataWriter

Throws:

IOException

getFrameType

public StackMap.EntryType getFrameType()