Object
- StackMapUtils
- - InstructionListUtils
  - - DCInstrument

```
public class DCInstrument
extends InstructionListUtils
```
Instruments a class file to perform Dynamic Comparability.
The DCInstrument class is responsible for modifying another class's bytecodes. Specifically, its main task is to add calls into the DynComp Runtime to calculate comparability values. These added calls are sometimes referred to as "hooks".

Nested Class Summary

Nested Classes
Modifier and Type Class Description

protected static class DCInstrument.JUnitState
Possible states of JUnit test discovery.

Field Summary

Fields
Modifier and Type	Field	Description
`protected boolean`	`constructor_is_initialized`	Has an `<init>` method completed initialization?
`protected ObjectType`	`dcomp_marker`
`protected @DotSeparatedIdentifiers String`	`dcomp_prefix`	Either "java.lang" or "daikon.dcomp".
`protected @DotSeparatedIdentifiers String`	`dcompRuntimeClassName`	Either "daikon.dcomp.DCRuntime" or "java.lang.DCRuntime".
`protected static SimpleLog`	`debug_dup`	Log file if debug_dup is enabled.
`protected static SimpleLog`	`debug_native`	Log file if debug_native is enabled.
`protected static SimpleLog`	`debug_transform`	Debug information about which classes and/or methods are transformed and why.
`protected static boolean`	`debugGetDefiningInterface`	If true, enable `getDefiningInterface(org.apache.bcel.classfile.JavaClass, java.lang.String, org.apache.bcel.generic.Type[])` debugging.
`protected static boolean`	`debugHandleInvoke`	If true, enable `handleInvoke(org.apache.bcel.generic.InvokeInstruction)` debugging.
`protected static boolean`	`debugJUnitAnalysis`	If true, enable JUnit analysis debugging.
`protected ClassGen`	`gen`	ClassGen for the current class.
`protected static InstructionList`	`global_catch_il`
`protected static CodeExceptionGen`	`global_exception_handler`
`protected InstructionFactory`	`ifact`	The BCEL InstructionFactory for generating byte code instructions.
`protected boolean`	`in_jdk`	Is the current class a member of the JDK?
`protected static Type[]`	`integer_arg`	Type array with an int.
`protected static Type`	`javalangClass`	ObjectType for "java.lang.Class".
`protected static ObjectType`	`javalangObject`
`protected static boolean`	`junit_parse_seen`	Have we seen 'JUnitCommandLineParseResult.parse'?
`protected static DCInstrument.JUnitState`	`junit_state`	Current state of JUnit test discovery.
`protected static Set<String>`	`junitTestClasses`	Set of JUnit test classes.
`protected @Nullable ClassLoader`	`loader`	The loader that loaded the Class to instrument.
`protected MethodGen`	`mgen`	MethodGen for the current method.
`protected static DCInstrument.MethodDef[]`	`obj_methods`	List of Object methods.
`protected static Type[]`	`object_arg`	Type array with an object.
`protected static Type`	`object_arr`
`protected static Type[]`	`object_int`	Type array with an object and an int.
`protected JavaClass`	`orig_class`	Unmodified version of input class.
`static boolean`	`quit_if_error`	Used when testing to continue processing if an error occurs.
`protected List<String>`	`skipped_methods`	Keeps track of the methods that were not successfully instrumented.
`protected static Type[]`	`string_arg`	Type array with a string.
`protected LocalVariableGen`	`tag_frame_local`	Local that stores the tag frame for the current method.
`protected static ObjectType`	`throwable`
`protected static Type[]`	`two_objects`	Type array with two objects.
`protected static String[]`	`uninit_classes`	Array of classes whose fields are not initialized from java.

Fields inherited from class StackMapUtils
debugInstrument, firstLocalIndex, initialLocalsCount, initialTypeList, liveRangeEnd, liveRangeOperandSize, liveRangeStart, liveRangeType, needStackMap, numberActiveLocals, pool, runningOffset, smta, stackMapTable, stackTypes

Constructor Summary

Constructors
Constructor	Description
`DCInstrument(JavaClass orig_class, boolean in_jdk, @Nullable ClassLoader loader)`	Initialize with the original class and whether or not the class is part of the JDK.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`add_create_tag_frame(MethodGen mg)`	Adds the code to create the tag frame to the beginning of the method.
`void`	`add_enter(MethodGen mg, MethodInfo mi, int method_info_index)`	Adds the call to DCRuntime.enter to the beginning of the method.
`void`	`add_exception_handler(MethodGen mg, InstructionList catch_il)`	Adds a try/catch block around the entire method.
`void`	`build_exception_handler(MethodGen mg)`	Adds a try/catch block around the entire method.
`protected String`	`full_name(JavaClass jc, Field f)`	Return the fully qualified fieldname of the specified field.
`List<String>`	`get_skipped_methods()`	Returns the list of uninstrumented methods.
`void`	`install_exception_handler(MethodGen mg)`	Adds a try/catch block around the entire method.
`JavaClass`	`instrument()`	Instruments the original class to perform dynamic comparabilty and returns the new class definition.
`JavaClass`	`instrument_jdk()`	Instruments a JDK class to perform dynamic comparability and returns the new class definition.
`void`	`instrument_method(MethodGen mg)`	Instrument the specified method for dynamic comparability.
`protected String`	`simplify_method_name(Method m)`	Return simplified name of a method.

Methods inherited from class InstructionListUtils
append_inst, build_il, calculateLiveLocalTypes, calculateLiveStackTypes, delete_instructions, insertAtMethodStart, insertBeforeHandle, replaceInstructions

Methods inherited from class StackMapUtils
addNewParameter, addString, adjust_code_for_locals_change, bcelCalcStackTypes, buildUninitializedNewMap, create_local_from_live_range, create_method_scope_local, createNewStackMapAttribute, findStackMapEqual, findStackMapIndexAfter, findStackMapIndexBefore, fixLocalVariableTable, gen_locals, gen_locals_from_byte_codes, gen_locals_from_byte_codes, generate_Type_from_StackMapType, generateStackMapTypeFromType, get_attribute_name, get_local_variable_type_table_attribute, getSize, getStackMapTable_attribute, is_local_variable_type_table, isStackMapTable, modifyStackMapsForSwitches, printStackMapTable, remove_local_variable_type_table, set_method_stackTypes, setCurrentStackMapTable, typeToClassGetName, update_full_frameStackMap_entries, updateStackMapOffset, updateUninitializedNewOffsets

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

- Field Detail
  - quit_if_error
```
public static boolean quit_if_error
```
    Used when testing to continue processing if an error occurs. Currently, This flag is only used by BuildJDK.
  - orig_class
```
protected JavaClass orig_class
```
    Unmodified version of input class.
  - gen
```
protected ClassGen gen
```
    ClassGen for the current class.
  - mgen
```
protected MethodGen mgen
```
    MethodGen for the current method.
  - in_jdk
```
protected boolean in_jdk
```
    Is the current class a member of the JDK?
  - ifact
```
protected InstructionFactory ifact
```
    The BCEL InstructionFactory for generating byte code instructions.
  - loader
```
protected @Nullable ClassLoader loader
```
    The loader that loaded the Class to instrument.
  - constructor_is_initialized
```
protected boolean constructor_is_initialized
```
    Has an <init> method completed initialization?
  - tag_frame_local
```
protected LocalVariableGen tag_frame_local
```
    Local that stores the tag frame for the current method.
  - two_objects
```
protected static Type[] two_objects
```
    Type array with two objects.
  - object_int
```
protected static Type[] object_int
```
    Type array with an object and an int.
  - string_arg
```
protected static Type[] string_arg
```
    Type array with a string.
  - integer_arg
```
protected static Type[] integer_arg
```
    Type array with an int.
  - object_arg
```
protected static Type[] object_arg
```
    Type array with an object.
  - javalangClass
```
protected static Type javalangClass
```
    ObjectType for "java.lang.Class".
  - object_arr
```
protected static Type object_arr
```
  - throwable
```
protected static ObjectType throwable
```
  - dcomp_marker
```
protected ObjectType dcomp_marker
```
  - javalangObject
```
protected static ObjectType javalangObject
```
  - debug_native
```
protected static SimpleLog debug_native
```
    Log file if debug_native is enabled.
  - debug_dup
```
protected static SimpleLog debug_dup
```
    Log file if debug_dup is enabled.
  - debug_transform
```
protected static SimpleLog debug_transform
```
    Debug information about which classes and/or methods are transformed and why. Use debugInstrument for actual instrumentation details.
  - debugJUnitAnalysis
```
protected static final boolean debugJUnitAnalysis
```
    If true, enable JUnit analysis debugging.
    
    See Also:
    
    Constant Field Values
  - debugGetDefiningInterface
```
protected static final boolean debugGetDefiningInterface
```
    If true, enable getDefiningInterface(org.apache.bcel.classfile.JavaClass, java.lang.String, org.apache.bcel.generic.Type[]) debugging.
    
    See Also:
    
    Constant Field Values
  - debugHandleInvoke
```
protected static final boolean debugHandleInvoke
```
    If true, enable handleInvoke(org.apache.bcel.generic.InvokeInstruction) debugging.
    
    See Also:
    
    Constant Field Values
  - skipped_methods
```
protected List<String> skipped_methods
```
    Keeps track of the methods that were not successfully instrumented.
  - dcomp_prefix
```
protected @DotSeparatedIdentifiers String dcomp_prefix
```
    Either "java.lang" or "daikon.dcomp".
  - dcompRuntimeClassName
```
protected @DotSeparatedIdentifiers String dcompRuntimeClassName
```
    Either "daikon.dcomp.DCRuntime" or "java.lang.DCRuntime".
  - junitTestClasses
```
protected static Set<String> junitTestClasses
```
    Set of JUnit test classes.
  - junit_state
```
protected static DCInstrument.JUnitState junit_state
```
    Current state of JUnit test discovery.
  - junit_parse_seen
```
protected static boolean junit_parse_seen
```
    Have we seen 'JUnitCommandLineParseResult.parse'?
  - uninit_classes
```
protected static String[] uninit_classes
```
    Array of classes whose fields are not initialized from java. Since the fields are not initialized from java, their tag storage is not allocated as part of a store, but rather must be allocated as part of a load. We call a special runtime method for this so that we can check for this in other cases.
  - obj_methods
```
protected static DCInstrument.MethodDef[] obj_methods
```
    List of Object methods. Since we can't instrument Object, none of these can be instrumented, and most of them don't provide useful comparability information anyway. The equals method and the clone method are special-cased in the handleInvoke(org.apache.bcel.generic.InvokeInstruction) routine.
  - global_catch_il
```
protected static InstructionList global_catch_il
```
  - global_exception_handler
```
protected static CodeExceptionGen global_exception_handler
```
- Constructor Detail
  - DCInstrument
```
public DCInstrument(JavaClass orig_class,
                    boolean in_jdk,
                    @Nullable ClassLoader loader)
```
    Initialize with the original class and whether or not the class is part of the JDK.
- Method Detail
  - instrument
```
public JavaClass instrument()
```
    Instruments the original class to perform dynamic comparabilty and returns the new class definition.
    
    Returns:
    
    the modified JavaClass
  - instrument_jdk
```
public JavaClass instrument_jdk()
```
    Instruments a JDK class to perform dynamic comparability and returns the new class definition. A second version of each method in the class is created which is instrumented for comparability.
    
    Returns:
    
    the modified JavaClass
  - instrument_method
```
public void instrument_method(MethodGen mg)
```
    Instrument the specified method for dynamic comparability.
    
    Parameters:
    
    mg - MethodGen for the method to be instrumented
  - get_skipped_methods
```
public List<String> get_skipped_methods()
```
    Returns the list of uninstrumented methods. (Note: instrument_jdk() needs to have been called first.)
  - build_exception_handler
```
public void build_exception_handler(MethodGen mg)
```
    Adds a try/catch block around the entire method. If an exception occurs, the tag stack is cleaned up and the exception is rethrown.
  - add_exception_handler
```
public void add_exception_handler(MethodGen mg,
                                  InstructionList catch_il)
```
    Adds a try/catch block around the entire method.
  - install_exception_handler
```
public void install_exception_handler(MethodGen mg)
```
    Adds a try/catch block around the entire method.
  - add_create_tag_frame
```
public void add_create_tag_frame(MethodGen mg)
```
    Adds the code to create the tag frame to the beginning of the method. This needs to be before the call to DCRuntime.enter (since it passed to that method).
  - add_enter
```
public void add_enter(MethodGen mg,
                      MethodInfo mi,
                      int method_info_index)
```
    Adds the call to DCRuntime.enter to the beginning of the method.
    
    Parameters:
    
    mg - method to modify
    
    mi - MethodInfo for method
    
    method_info_index - index for MethodInfo
  - full_name
```
protected String full_name(JavaClass jc,
                           Field f)
```
    Return the fully qualified fieldname of the specified field.
    
    Parameters:
    
    jc - class containing the field
    
    f - the field
    
    Returns:
    
    string containing the fully qualified name
  - simplify_method_name
```
protected String simplify_method_name(Method m)
```
    Return simplified name of a method. Both exceptions and annotations are removed.
    
    Parameters:
    
    m - the method
    
    Returns:
    
    string containing the simplified method name

Class DCInstrument

Nested Class Summary

Field Summary

Fields inherited from class StackMapUtils

Constructor Summary

Method Summary

Methods inherited from class InstructionListUtils

Methods inherited from class StackMapUtils

Methods inherited from class Object

Field Detail

quit_if_error

orig_class

gen

mgen

in_jdk

ifact

loader

constructor_is_initialized

tag_frame_local

two_objects

object_int

string_arg

integer_arg

object_arg

javalangClass

object_arr

throwable

dcomp_marker

javalangObject

debug_native

debug_dup

debug_transform

debugJUnitAnalysis

debugGetDefiningInterface

debugHandleInvoke

skipped_methods

dcomp_prefix

dcompRuntimeClassName

junitTestClasses

junit_state

junit_parse_seen

uninit_classes

obj_methods

global_catch_il

global_exception_handler

Constructor Detail

DCInstrument

Method Detail

instrument

instrument_jdk

instrument_method

get_skipped_methods

build_exception_handler

add_exception_handler

install_exception_handler

add_create_tag_frame

add_enter

full_name

simplify_method_name