org.intellij.lang.annotations

Annotation Type Flow

@Retention(value=CLASS)
 @Target(value={PARAMETER,METHOD})
public @interface Flow

This annotation assists the 'Data flow to this' feature by describing data flow from the method parameter to the corresponding container (e.g. ArrayList.add(item)) or from the container to the method return value (e.g. Set.toArray()) or between method parameters (e.g. System.arraycopy(array1, 0, array2, length))

Field Summary

Fields

Modifier and Type	Fields and Description
static java.lang.String	DEFAULT_SOURCE
static java.lang.String	DEFAULT_TARGET
static java.lang.String	RETURN_METHOD_TARGET
static java.lang.String	THIS_SOURCE
static java.lang.String	THIS_TARGET

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
java.lang.String	source Denotes the source of the data flow. Allowed values are: THIS_SOURCE - Means that the data flows from this container. E.g.
boolean	sourceIsContainer true if the data source is container and we should track not the expression but its contents. E.g.
java.lang.String	target Denotes the destination of the data flow. Allowed values are: THIS_TARGET - Means that the data flows inside this container (of the class the annotated method belongs to). E.g.
boolean	targetIsContainer true if the data target is container and we should track not the expression but its contents. E.g.

Field Detail

DEFAULT_SOURCE

public static final java.lang.String DEFAULT_SOURCE

THIS_SOURCE

public static final java.lang.String THIS_SOURCE

DEFAULT_TARGET

public static final java.lang.String DEFAULT_TARGET

RETURN_METHOD_TARGET

public static final java.lang.String RETURN_METHOD_TARGET

THIS_TARGET

public static final java.lang.String THIS_TARGET

Element Detail

source

public abstract java.lang.String source

Denotes the source of the data flow.
Allowed values are:

• THIS_SOURCE - Means that the data flows from this container.
  E.g. annotation for java.util.List method get(index) means the method reads contents of list and returns it.
  @Flow(source = THIS_SOURCE) T get(int index);
  
• this.Field name - means that the data flows from this container some (synthetic) field.
  E.g. annotation for java.util.Map.keySet() method here means that it returns data from the map from the field named "keys".
  @Flow(source = "this.keys") Set<K> keySet();

By default, the source() value is:

• THIS_SOURCE if the method was annotated, e.g.
  @Flow(sourceIsContainer=true, targetIsContainer=true) Object[] Collection.toArray()
  Here the annotation tells us that java.util.Collection.toArray() method
  reads the contents of this collection (source=THIS_SOURCE by default) and passes it outside.
• Corresponding argument if the method parameter was annotated, e.g.
  void List.add(@Flow(targetIsContainer=true) E item)
  Here the annotation tells us that java.util.List.add(E item) method
  takes the argument (source="item" by default) and passes it to this collection.

Default:

"The method argument (if parameter was annotated) or this container (if instance method was annotated)"

sourceIsContainer

public abstract boolean sourceIsContainer

true if the data source is container and we should track not the expression but its contents.
E.g. the java.util.ArrayList constructor takes the collection and stores its contents:
ArrayList(

 @Flow(sourceIsContainer=true, targetIsContainer=true) Collection<? extends E> collection 

)
By default it's false.

Default:

false

target

public abstract java.lang.String target

Denotes the destination of the data flow.
Allowed values are:

• THIS_TARGET - Means that the data flows inside this container (of the class the annotated method belongs to).
  E.g. annotation for java.util.List method add(element) means the method takes the argument and passes it to this collection.
  boolean add(@Flow(target=THIS_TARGET, targetIsContainer=true) E element);
  
• Parameter name - means the data flows to this parameter.
  E.g.
  void arraycopy(@Flow(sourceIsContainer=true, target="dest", targetIsContainer=true) Object src, int srcPos, Object dest, int destPos, int length)
  means that java.lang.System.arraycopy() method takes its first argument and passes it to the "dest" parameter.
• this.Field name - means that the data flows to this container in some (synthetic) field.
  E.g. annotation for java.util.Map.put(key, value) method here means that it takes the argument 'key' and stores the data in some (hidden) field named "keys".
  V put(@Flow(target = "this.keys", targetIsContainer=true) K key, V value);

By default, the target() value is:

• THIS_TARGET if the parameter was annotated, e.g.
  void List.set(int index, @Flow(targetIsContainer=true) E element)
  Here the annotation tells us that java.util.List.set(index, element) method
  reads its second argument 'element' and passes it to this collection (target=THIS_TARGET by default).
• RETURN_METHOD_TARGET if the method was annotated, e.g.:
  @Flow(sourceIsContainer=true) E List.remove(int index)
  Here the annotation tells us that java.util.List.remove(int index) method
  returns the data from its collection (target=RETURN_METHOD_TARGET by default).

Default:

"This container (if the parameter was annotated) or the return value (if instance method was annotated)"

targetIsContainer

public abstract boolean targetIsContainer

true if the data target is container and we should track not the expression but its contents.
E.g. the java.lang.System.arraycopy() method parameter 'dest' is actually an array:
void arraycopy(@Flow(sourceIsContainer=true, target="dest", targetIsContainer=true) Object src, int srcPos, Object dest, int destPos, int length)
By default it's false.

Default:

false