public abstract class

AbstractDCollectionOptimizer

extends AbstractPlugin
implements IDOptimizer
java.lang.Object
   ↳ com.pnfsoftware.jeb.core.AbstractPlugin
     ↳ com.pnfsoftware.jeb.core.units.code.android.ir.AbstractDCollectionOptimizer

Class Overview

Base class for dexdec (DEX decompiler) IR optimizer plugins working on a collection of IR contexts. Those plugins can access and modify the intermediate representation of a group of methods being decompiled. They can be used to implement a wide range of optimizations, from trivial code clean-up to the most complex deobfuscation passes. Internally, dexdec uses IR optimizers to perform dead-code removal, variable substitutions, immediate propagation, restructuring, constant folding, arithmetic operation simplifications, deobfuscations such as control-flow unflattening, etc.

Optimizers are usually managed by master optimizers (also called orchestrators). Third-party optimizer plugins can be automatically registered when creating an orchestrator. Refer to createMasterOptimizer.

Life-cycle information:
- plugins are reused (i.e. the performOnCollection() method is called multiple times)
- thread-safety:
-- Python script plugins must be thread-safe: a plugin instance may be executed by multiple threads concurrently
-- Java plugins (including Java script plugins) are not required to be thread-safe: a plugin instance will not be executed by multiple threads concurrently

See Also

Summary

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Inherited Constants
From interface com.pnfsoftware.jeb.core.units.code.android.ir.IDOptimizer
Fields
public List<IDMethodContext> ctxlist The list of IR method contexts available to the optimizer.
public IDexDecompilerUnit decomp Managing dex decompiler.
public IDexUnit dex Underlying dex code.
public IDGlobalContext g IR global context.
public static final ILogger logger Public logger accessible by the implementing optimizer.
public IJavaOperatorFactory of IR/AST operation factory reference (for convenience).
public IJavaTypeFactory tf IR/AST type factory reference (for convenience).
Public Constructors
AbstractDCollectionOptimizer()
Create a standard optimizer.
AbstractDCollectionOptimizer(DOptimizerType type)
Create an optimizer.
AbstractDCollectionOptimizer(DOptimizerType type, String name)
Create an optimizer.
Public Methods
void assignLocalFields(List<IDMethodContext> _ctxlist)
This convenience method can be used to assign the object's attributes from the values of the provided IR contexts.
String getName()
Retrieve the plugin name.
EditablePluginInformation getPluginInformation()
Retrieve basic information about the plugin, such as name, version, author, and organization.
double getPriority()
Get the optimizer priority.
Set<String> getTags()
Get the optimizer tags.
DOptimizerType getType()
Get the optimizer type.
boolean isCollectionOptimizer()
Determine whether this optimizer performs on a single method or an a collection of methods.
boolean isEnabled()
Determine whether the optimizer is enabled or not.
int perform(IDMethodContext ctx)
Run the optimizer on the provided target method.
abstract int performOnCollection()
An optimizer must implement this method.
final int performOnCollection(List<IDMethodContext> ctxlist, Map<IDMethodContext, Integer> pmcntmap)
Run the optimizer on the provided collection of methods.
void resetLocalFields()
Reset this object's attributes.
void setEnabled(boolean enabled)
Enable or disable this optimizer.
Protected Methods
void addTag(String tag)
void checkInterrupted()
Verify if an interruption request was made by the managing decompiler.
void recordMethodOptimization(IDMethodContext ctx, int cnt)
void removeTag(String tag)
void setName(String name)
Set the optimizer name.
void setPriority(double priority)
Set the optimizer priority.
void setType(DOptimizerType type)
Set the optimizer type.
[Expand]
Inherited Methods
From class com.pnfsoftware.jeb.core.AbstractPlugin
From class java.lang.Object
From interface com.pnfsoftware.jeb.core.IPlugin
From interface com.pnfsoftware.jeb.core.units.code.android.ir.IDOptimizer

Fields

public List<IDMethodContext> ctxlist

The list of IR method contexts available to the optimizer. A collection is not a class. Those IR contexts may represent methods from multiple classes.

public IDexDecompilerUnit decomp

Managing dex decompiler.

public IDexUnit dex

Underlying dex code.

public IDGlobalContext g

IR global context.

public static final ILogger logger

Public logger accessible by the implementing optimizer. Writing to the logger should be favored over writing directly to stdout.

public IJavaOperatorFactory of

IR/AST operation factory reference (for convenience).

public IJavaTypeFactory tf

IR/AST type factory reference (for convenience).

Public Constructors

public AbstractDCollectionOptimizer ()

Create a standard optimizer.

public AbstractDCollectionOptimizer (DOptimizerType type)

Create an optimizer.

public AbstractDCollectionOptimizer (DOptimizerType type, String name)

Create an optimizer.

Public Methods

public void assignLocalFields (List<IDMethodContext> _ctxlist)

This convenience method can be used to assign the object's attributes from the values of the provided IR contexts.

Parameters
_ctxlist an IR context

public String getName ()

Retrieve the plugin name. Should be consistent with the value returned by getPluginInformation().getName().

public EditablePluginInformation getPluginInformation ()

Retrieve basic information about the plugin, such as name, version, author, and organization.

Returns
  • the plugin information

public double getPriority ()

Get the optimizer priority. A higher value means a higher priority. Priorities are used by optimizer orchestrators to determine in which order optimizers should be executed.

Returns
  • the default priority

public Set<String> getTags ()

Get the optimizer tags. An optimizer may have 0, 1, or more tags. A tag is a non-null, non-empty string.

Returns
  • a collection of tags; may be empty (tags are optional), but never null

public DOptimizerType getType ()

Get the optimizer type. Types are used by optimizer orchestrators to determine whether an optimizer should run.

public boolean isCollectionOptimizer ()

Determine whether this optimizer performs on a single method or an a collection of methods.

public boolean isEnabled ()

Determine whether the optimizer is enabled or not. This method is used by optimizer orchestrators to determine whether an optimizer can be scheduled for execution.

Returns
  • true if this optimizer is enabled

public int perform (IDMethodContext ctx)

Run the optimizer on the provided target method.

For this method to be called by an orchestrator, isCollectionOptimizer() must return false.

Parameters
ctx a method context
Returns
  • number of optimizations performed

public abstract int performOnCollection ()

An optimizer must implement this method. This method is called by a master optimizer to perform optimizations on the provided target contexts.

Returns
  • total count of optimizations; it is also recommended to #recordOptimization(IDMethodContext, int) register per-method optimizations

public final int performOnCollection (List<IDMethodContext> ctxlist, Map<IDMethodContext, Integer> pmcntmap)

Run the optimizer on the provided collection of methods.

For this method to be called by an orchestrator, isCollectionOptimizer() must return true.

Parameters
ctxlist a collection of method contexts
pmcntmap optional output map that will receive the per-method optimization counts
Returns
  • number of optimizations performed

public void resetLocalFields ()

Reset this object's attributes. Same as #assignLocalFields(IDMethodContext) assignLocalFields(null).

public void setEnabled (boolean enabled)

Enable or disable this optimizer. This flag is checked by a master optimizer.

Protected Methods

protected void addTag (String tag)

protected void checkInterrupted ()

Verify if an interruption request was made by the managing decompiler. This method may be called when potentially length computations are performed in a loop.

protected void recordMethodOptimization (IDMethodContext ctx, int cnt)

protected void removeTag (String tag)

protected void setName (String name)

Set the optimizer name. To be used by the constructor.

Parameters
name if null, a name will be auto-generated

protected void setPriority (double priority)

Set the optimizer priority. To be used by the constructor.

Parameters
priority the new priority (high means higher priority). When optimizers are managed and run by an orchestrator, the optimizers with a higher priority are run before those having a lower priority. The default priority is 0.

protected void setType (DOptimizerType type)

Set the optimizer type. To be used by the constructor.

Parameters
type if null, a standard optimizer is assumed