Package ghidra.program.model.pcode

Class PartialUnion

java.lang.Object

ghidra.program.model.data.AbstractDataType

ghidra.program.model.pcode.PartialUnion

All Implemented Interfaces:

DataType

public class PartialUnion
extends AbstractDataType

A data-type representing an unspecified piece of a parent Union data-type. This is used internally by the decompiler to label Varnodes representing partial symbols, where the part is known to be contained in a Union data-type. Within the isolated context of a Varnode, its not possible to resolve to a specific field of the Union because the Varnode may be used in multiple ways.

Field Summary

Fields inherited from class ghidra.program.model.data.AbstractDataType

categoryPath, dataMgr, name

Fields inherited from interface ghidra.program.model.data.DataType

CONFLICT_SUFFIX, DEFAULT, NO_LAST_CHANGE_TIME, NO_SOURCE_SYNC_TIME, TYPEDEF_ATTRIBUTE_PREFIX, TYPEDEF_ATTRIBUTE_SUFFIX, VOID

Method Summary

Modifier and Type	Method	Description
DataType	clone(DataTypeManager dtm)	Returns an instance of this DataType using the specified DataTypeManager to allow its use of the corresponding DataOrganization while retaining its unique identity (see DataType.getUniversalID() and archive association (see DataType.getSourceArchive()) if applicable.
DataType	copy(DataTypeManager dtm)	Returns a new instance (shallow copy) of this DataType with a new identity and no source archive association.
int	getAlignedLength()	Get the aligned-length of this datatype as a number of 8-bit bytes.
int	getAlignment()	Gets the alignment to be used when aligning this datatype within another datatype.
Settings	getDefaultSettings()	Gets the settings for this data type.
String	getDescription()	Get a String briefly describing this DataType.
int	getLength()	Get the length of this DataType as a number of 8-bit bytes.
int	getOffset()
DataType	getParent()
String	getRepresentation(MemBuffer buf, Settings settings, int length)	Get bytes from memory in a printable format for this type.
SettingsDefinition[]	getSettingsDefinitions()	Get the list of settings definitions available for use with this datatype.
DataType	getStrippedDataType()	Get a data-type that can be used as a formal replacement for this (internal) data-type
Object	getValue(MemBuffer buf, Settings settings, int length)	Returns the interpreted data value as an instance of the advertised value class.
Class<?>	getValueClass(Settings settings)	Get the Class of the value Object to be returned by this datatype (see DataType.getValue(MemBuffer, Settings, int)).
boolean	isEquivalent(DataType dt)	Check if the given datatype is equivalent to this datatype.

Methods inherited from class ghidra.program.model.data.AbstractDataType

addParent, dataTypeAlignmentChanged, dataTypeDeleted, dataTypeNameChanged, dataTypeReplaced, dataTypeSizeChanged, dependsOn, encodeRepresentation, encodeValue, getCategoryPath, getDataOrganization, getDataOrganization, getDataTypeManager, getDataTypePath, getDefaultAbbreviatedLabelPrefix, getDefaultLabelPrefix, getDefaultLabelPrefix, getDefaultOffcutLabelPrefix, getDisplayName, getDocs, getLastChangeTime, getLastChangeTimeInSourceArchive, getMnemonic, getName, getParents, getPathName, getSourceArchive, getTypeDefSettingsDefinitions, getUniversalID, hasLanguageDependantLength, isDeleted, isEncodable, isNotYetDefined, isZeroLength, removeParent, replaceWith, setCategoryPath, setDescription, setLastChangeTime, setLastChangeTimeInSourceArchive, setName, setNameAndCategory, setSourceArchive, toString

Methods inherited from class java.lang.Object

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

Method Details

getParent

public DataType getParent()

Returns:

the Union data-type of which this is a part

getOffset

public int getOffset()

Returns:

the offset, in bytes, of this part within its parent Union

clone

public DataType clone(DataTypeManager dtm)

Description copied from interface: DataType

Returns an instance of this DataType using the specified DataTypeManager to allow its use of the corresponding DataOrganization while retaining its unique identity (see DataType.getUniversalID() and archive association (see DataType.getSourceArchive()) if applicable.

This instance will be returned if this datatype's DataTypeManager matches the specified dtm. The recursion depth of a clone will stop on any datatype whose DataTypeManager matches the specified dtm and simply use the existing datatype instance.

NOTE: In general, this method should not be used to obtain an instance to be modified. In most cases changes may be made directly to this instance if supported or to a DataType.copy(DataTypeManager) of this type.

Parameters:

dtm - the data-type manager instance whose data-organization should apply.

Returns:

cloned instance which may be the same as this instance

getLength

public int getLength()

Description copied from interface: DataType

Get the length of this DataType as a number of 8-bit bytes.

For primitive datatypes this reflects the smallest varnode which can be used to contain its value (i.e., raw data length).

Example: For x86 32-bit gcc an 80-bit long double raw data length of 10-bytes will fit within a floating point register while its aligned-length of 12-bytes is used by the gcc compiler for data/array/component allocations to maintain alignment (i.e., sizeof(long double) ).

NOTE: Other than the VoidDataType, no datatype should ever return 0, even if DataType.isZeroLength(), and only Dynamic/FactoryDataType datatypes should return -1. If DataType.isZeroLength() is true a length of 1 should be returned. Where a zero-length datatype can be handled (e.g., Composite) the DataType.isZeroLength() method should be used.

Returns:

the length of this DataType

getAlignedLength

public int getAlignedLength()

Description copied from interface: DataType

Get the aligned-length of this datatype as a number of 8-bit bytes.

For primitive datatypes this is equivalent to the C/C++ "sizeof" operation within source code and should be used when determining Array element length or component sizing for a Composite. For Pointer, Composite and Array types this will return the same value as DataType.getLength().

Example: For x86 32-bit gcc an 80-bit long double raw data length of 10-bytes will fit within a floating point register while its aligned-length of 12-bytes is used by the gcc compiler for data/array/component allocations to maintain alignment (i.e., sizeof(long double) ).

NOTE: Other than the VoidDataType, no datatype should ever return 0, even if DataType.isZeroLength(), and only Dynamic / FactoryDataType / FunctionDefinition datatypes should return -1. If DataType.isZeroLength() is true a length of 1 should be returned.

Returns:

byte length of binary encoding.

getDescription

public String getDescription()

Description copied from interface: DataType

Get a String briefly describing this DataType.

Returns:

a one-liner describing this DataType.

getValue

public Object getValue(MemBuffer buf,
 Settings settings,
 int length)

Description copied from interface: DataType

Returns the interpreted data value as an instance of the advertised value class.

For instance, Pointer data types should return an Address object (or null), or integer data types should return a Scalar object.

Parameters:

buf - the data buffer

settings - the settings to use.

length - indicates the maximum number of bytes that may be consumed by a Dynamic datatype, otherwise this value is ignored. A value of -1 may be specified to allow a Dynamic datatype to determine the length based upon the actual data bytes

Returns:

the data object, or null if data is invalid

getRepresentation

public String getRepresentation(MemBuffer buf,
 Settings settings,
 int length)

Description copied from interface: DataType

Get bytes from memory in a printable format for this type.

Parameters:

buf - the data.

settings - the settings to use for the representation.

length - the number of bytes to represent.

Returns:

the representation of the data in this format, never null.

getSettingsDefinitions

public SettingsDefinition[] getSettingsDefinitions()

Description copied from interface: DataType

Get the list of settings definitions available for use with this datatype.

In the case of a TypeDef, the return list will include the TypeDefSettingsDefinition list from the associated base data type.

Unlike TypeDefSettingsDefinition standard settings definitions generally support default, component-default and data-instance use. In addition, standard settings definitions are never considered during DataType.isEquivalent(DataType) checking or during the resolve process.

Returns:

list of the settings definitions for this datatype.

getDefaultSettings

public Settings getDefaultSettings()

Description copied from interface: DataType

Gets the settings for this data type. The settings may have underlying default settings and may in turn become defaults for instance-specific settings (e.g., Data or DataTypeComponent). It is important to note that these settings are tied to a specific DataType instantiation so it is important to understand the scope of its use. Example: The BuiltInDataTypeManager has its own set of DataType instances which are separate from those which have been instantiated or resolved to a specific Program/Archive DataTypeManager. Settings manipulation may be disabled by default in some instances.

Returns:

the settings for this dataType.

copy

public DataType copy(DataTypeManager dtm)

Description copied from interface: DataType

Returns a new instance (shallow copy) of this DataType with a new identity and no source archive association.

Any reference to other datatypes will use DataType.clone(DataTypeManager).

Parameters:

dtm - the data-type manager instance whose data-organization should apply.

Returns:

new instanceof of this datatype

getValueClass

public Class<?> getValueClass(Settings settings)

Description copied from interface: DataType

Get the Class of the value Object to be returned by this datatype (see DataType.getValue(MemBuffer, Settings, int)).

Parameters:

settings - the relevant settings to use or null for default.

Returns:

Class of the value to be returned by this datatype or null if it can vary or is unspecified. Types which correspond to a string or char array will return the String class.

isEquivalent

public boolean isEquivalent(DataType dt)

Description copied from interface: DataType

Check if the given datatype is equivalent to this datatype.

The precise meaning of "equivalent" is datatype dependent.
NOTE: if invoked by a DB object or manager it should be invoked on the DataTypeDB object passing the other datatype as the argument.

Parameters:

dt - the datatype being tested for equivalence.

Returns:

true if the if the given datatype is equivalent to this datatype.

getAlignment

public int getAlignment()

Description copied from interface: DataType

Gets the alignment to be used when aligning this datatype within another datatype.

Returns:

this datatype's alignment.

getStrippedDataType

public DataType getStrippedDataType()

Get a data-type that can be used as a formal replacement for this (internal) data-type

Returns:

a replacement data-type