Package de.fraunhofer.aisec.cpg.graph.statements.expressions

Class Expression

java.lang.Object
de.fraunhofer.aisec.cpg.graph.Node
de.fraunhofer.aisec.cpg.graph.statements.Statement
de.fraunhofer.aisec.cpg.graph.statements.expressions.Expression
All Implemented Interfaces:
DeclarationHolder, HasType, Persistable, IVisitable<de.fraunhofer.aisec.cpg.graph.Node>
Direct Known Subclasses:
ArrayCreationExpression, ArrayRangeExpression, ArraySubscriptionExpression, BinaryOperator, CallExpression, CastExpression, CompoundStatementExpression, ConditionalExpression, DeclaredReferenceExpression, DeleteExpression, DesignatedInitializerExpression, ExpressionList, InitializerListExpression, Literal, NewExpression, TypeExpression, TypeIdExpression, UnaryOperator, UninitializedValue
public class Expression
extends Statement
implements HasType
Represents one expression. It is used as a base class for multiple different types of expressions. The only constraint is, that each expression has a type.

Note: In our graph, Expression is inherited from Statement. This is a constraint of the C++ language. In C++, it is valid to have an expression (for example a Literal) as part of a function body, even though the expression value is not used. Consider the following code: int main() { 1; }

This is not possible in Java, the aforementioned code example would prompt a compile error.

  • Field Details

    • type

      protected Type type
      The type of the value after evaluation.

  • Constructor Details

    • Expression

      public Expression()

  • Method Details

    • getType

      public Type getType()
      Specified by:
      getType in interface HasType

    • getPropagationType

      public Type getPropagationType()
      Specified by:
      getPropagationType in interface HasType
      Returns:
      The returned Type is always the same as getType() with the exception of ReferenceType since there is no case in which we want to propagate a reference when using typeChanged()

    • updateType

      public void updateType​(Type type)
      Description copied from interface: HasType
      Sideeffect free type modification WARNING: This should only be used by the TypeSystem Pass
      Specified by:
      updateType in interface HasType
      Parameters:
      type - new type

    • updatePossibleSubtypes

      public void updatePossibleSubtypes​(java.util.Set<Type> types)
      Specified by:
      updatePossibleSubtypes in interface HasType

    • setType

      public void setType​(Type type, HasType root)
      Description copied from interface: HasType
      Set the node's type. This may start a chain of type listener notifications
      Specified by:
      setType in interface HasType
      Parameters:
      type - new type
      root - The node that initiated the type change chain. When a node receives a type setting command where root == this, we know that we have a type listener circle and can abort. If root == null, the type change is seen as an externally triggered event and subsequent type listeners receive the current node as their root.

    • getPossibleSubTypes

      public java.util.Set<Type> getPossibleSubTypes()
      Specified by:
      getPossibleSubTypes in interface HasType

    • setPossibleSubTypes

      public void setPossibleSubTypes​(java.util.Set<Type> possibleSubTypes, HasType root)
      Description copied from interface: HasType
      Set the node's possible subtypes. Listener circle detection works the same way as with HasType.setType(Type, HasType)
      Specified by:
      setPossibleSubTypes in interface HasType

    • resetTypes

      public void resetTypes​(Type type)
      Description copied from interface: HasType
      Used to set the type and clear the possible subtypes list for when a type is more precise than the current.
      Specified by:
      resetTypes in interface HasType
      Parameters:
      type - the more precise type

    • registerTypeListener

      public void registerTypeListener​(HasType.TypeListener listener)
      Specified by:
      registerTypeListener in interface HasType

    • unregisterTypeListener

      public void unregisterTypeListener​(HasType.TypeListener listener)
      Specified by:
      unregisterTypeListener in interface HasType

    • getTypeListeners

      public java.util.Set<HasType.TypeListener> getTypeListeners()
      Specified by:
      getTypeListeners in interface HasType

    • refreshType

      public void refreshType()
      Specified by:
      refreshType in interface HasType

    • toString

      public java.lang.String toString()
      Overrides:
      toString in class de.fraunhofer.aisec.cpg.graph.Node

    • equals

      public boolean equals​(java.lang.Object o)
      Overrides:
      equals in class Statement

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Statement